Vision Loss

Coding Dimension ID: 
325
Coding Dimension path name: 
Vision Loss

3D Modeling of Retina using Polymer Scaffolds for Understanding Disease Pathogenesis

Funding Type: 
Basic Biology IV
Grant Number: 
RB4-05785
ICOC Funds Committed: 
$1 526 319
Disease Focus: 
Vision Loss
Stem Cell Use: 
Embryonic Stem Cell
iPS Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Active
Public Abstract: 
Inherited retinal degenerations result in visual loss in patients as early as in their adolescence. Retinitis Pigmentosa includes a group of such degenerations which run in families and can result in legal blindness by 40 years of age. Even though we know by now a number of gene mutations which can cause these disorders, we do not understand how these mutations ultimately lead to loss of the cells. Recent advances in stem cell technologies now have provided us with the opportunity to gain a better understanding of the disorders. In this proposal, we plan to study the degenerative process by creating an eye-like structure in a dish using a combination of stem cell and bioengineering approaches. We plan to use 3D scaffolds to grow eye cells generated from pluripotent stem cells. We will directly compare normal retinal cells with cells derived from patients with Retinitis Pigmentosa. This approach will allow us to identify the processes that ultimately lead to the death of the photoreceptor cells int he eye and blindness. In the future, we could then extend this work to identify new drugs which will help halt or at least slow down the degeneration in these patients.
Statement of Benefit to California: 
Photoreceptor degenerations, including Retinitis Pigmentosa (RP), cause visual impairment for millions of patients in the United States and a number of patients in the state of California being one of the most populous states in the US. RP encompasses a group of retinal degeneration with a prevalence of 1 in 4000 and runs in families. Typical symptoms include night blindness followed by decreasing vision, and eventually legal blindness or, in many cases, complete blindness. RP is usually diagnosed in adolescents and young adults. Most people with RP are legally blind by age 40. There are no effective forms of treatment for a majority of these patients. Thus results in a tremendous stress on the state of CA's resources. In addition, there is both monetary and psychological stress on the families esp. in cases of Retinitis Pigmentosa as multiple family members are affected. The only way to potentially help these patients will be to either replace the dead cells with new photoreceptors or find ways to better understand the degenerative process in order to identify novel drugs to delay the progression of degeneration. The proposed research in this application is to generate eye tissue in a dish from patients with severe forms of Retinitis Pigmentosa in order to gain a better understanding of the disease. This will in turn help us in the future to identify new drugs to delay or stop the visual loss and this will attract new biotechnology partners in the state of CA.
Progress Report: 
  • Inherited retinal degenerations result in visual loss in patients early in life. Retinitis Pigmentosa, a form of inherited retinal degeneration, affects thousands of patients in US and in the state of California. The second most common gene whose mutation results in retinitis pigmentosa is RP1. How mutation in the gene result in loss of vision is not completely clear and we are working of gaining a better understanding of this by creating a 3D artificial retina in a dish. This invloved using stem-cell derived eye cells grown on patterned articifical scaffolds.
  • In our initial year of funding, we have improved our methodologies to make the various cells that make up the retina in the dish and are working on optimizing the generation of scaffolds. These scaffold will allow us to generated a retina, the light-sensing layer of the eye, in a dish. We have also over the course of the year generated stem cell lines using patient cells. Using the recent state-of-the-art technologies to convert patient cells to stem-cells, we have been able to convert blood cells to stem cells and then reconverted them to cells in the eye. We will now use these cells to better understand the degeneration and vision loss in the second year of the grant.

Human retinal progenitor cells as candidate therapy for retinitis pigmentosa

Funding Type: 
Early Translational II
Grant Number: 
TR2-01794
ICOC Funds Committed: 
$4 738 251
Disease Focus: 
Vision Loss
Stem Cell Use: 
Adult Stem Cell
oldStatus: 
Closed
Public Abstract: 
The targeted disease is retinitis pigmentosa (RP), is a severe form of blindness that runs in families. This disease is not overly common, yet represents an attainable near term target for stem cell therapy for a number of reasons: 1) RP destroys the light detecting cells of the retina but generally leaves the rest of the visual system and body unharmed, so the clinical goal is circumscribed; 2) RP is prototypical of degenerations of the nervous system, so a cure for this less common disease would accelerate progress towards new therapies for a range of more familiar conditions; 3) scientific research has shown that degenerating rods and cones can be spared in animals by transplanting particular types of stem cells, so the scientific feasibility of treating RP in this way has already been established in principle. The therapeutic approach is to save the light sensing cells of the eye (rod and cone photoreceptors) in people going blind using a type of stem cell obtained from the immature retina, but not from early embryos. These particular stem cells from the retina, known as progenitor cells, are capable of rescuing photoreceptors from degeneration following transplantation to the eye. These same cells are also highly efficient at becoming rod photoreceptors and this provides another more sustained pathway by which they preserve the crucial cone photoreceptors. In addition, there is evidence that the stem cells themselves might become functional photoreceptors and thereby stabilize the retina by directly replacing the dying cells in the patient’s eye. Thus, transplanted stem cells could treat the targeted disease of RP in multiple ways simultaneously. Importantly, there are a host of reasons why clinical trials in the eye are easier and safer than most locations in the body. The eye is an important proving ground for stem cell-based therapies and provides a stepping stone to many otherwise incurable diseases of the brain and spinal cord.
Statement of Benefit to California: 
Benefits to the state of California and its citizens are both direct and indirect. The direct benefit is medical in that there is currently no cure or established treatment for the individuals and families that suffer from the dreadful hereditary blindness known as retinitis pigmentosa. In addition, there are many people in California and throughout the world that suffer from degenerative diseases of the retina and central nervous system that could benefit from further development and alternate applications of the type of stem cell therapy proposed in the current application. The rapid progress that could be achieved via this proposal would help legitimize the use of stem cells and should thereby accelerate the development of stem cell-based therapeutics for a wide range of other diseases. In so doing there would be an indirect benefit to California by making our state a focal point for stem cell breakthroughs. This would increase medical capabilities, strengthen the [REDACTED], and energize local biotechnology companies with outside investment and a payoff in jobs and tax revenues.
Progress Report: 
  • At the end of Year 1 of the grant period, our team has made substantial progress and achieved quite a few of the milestones initially established for the entire 3 year period. A retinal cell bank has been established for research purposes and, in addition, initial clinical-grade cell production is now under way with the target of generating 3 clinical cell banks. We have shown that our human cells are able to help blind rats to see following transplantation to the eye. We have developed a range of methods to help prove the safety of our cells, both before and after transplantation, with definitive long term tests results to be obtained over the next few months. We have begun to unravel the molecular genetics of the cell and are specifically investigating what give them the ability to preserve vision in the face of progressive blindness. In summary, work is advancing rapidly and ahead of schedule, consistent with a realistic, achievable biological strategy. On behalf of the patients who we know are depending upon us, our team is committed to seeing this technology into the clinic in the shortest possible timeline.

Regeneration of Functional Human Corneal Epithelial Progenitor Cells

Funding Type: 
Early Translational II
Grant Number: 
TR2-01768
ICOC Funds Committed: 
$2 354 041
Disease Focus: 
Vision Loss
Stem Cell Use: 
Adult Stem Cell
Cell Line Generation: 
Adult Stem Cell
oldStatus: 
Active
Public Abstract: 
Over 3.2 million people worldwide are bilateral blind from corneal diseases. Limbal stem cell deficiency (LSCD) has been recognized as a major cause, either primary or secondary, of significant visual loss and blindness in many common corneal disorders. A healthy, transparent ocular surface is made up of non-keratinized, stratified squamous epithelium that is highly differentiated. The corneal epithelium is constantly renewed and maintained by the corneal epithelial stem cells, or limbal stem cells (LSCs) that are presumed to reside at the limbus, the junction between the cornea and conjunctiva. When the LSCs are deficient and unable to repopulate the corneal surface, the cornea surface will become opaque. Corneal transplant can’t survive and is contraindicated in LSCD. LSC transplantation, in the form of keratolimbal allograft to restore a transparent corneal surface, has been the main therapy in the United States. The 5-year survival of these allografts is about 30%, largely due to immune rejection. Transplantation of autologous limbal epithelial stem cells that have been expanded on tissue culture has successfully restored vision and revolutionized the patient specific stem-cell based therapy as recently reported by an Italian LSC transplant team. They have achieved a 68% success rate during a mean follow up time of 3 years. The expansion process requires mouse 3T3 feeder cells to grow a sufficient amount of stem cells for transplantation. To reduce cross-contamination from animal products, LSCs that are expanded in a xenobiotic-free culture system has been established; however, the 3-year survival rate of these cells after transplantation is 50% and only 30% survive at 5 year, suggestive of inefficient expansion without the mouse feeders. Therefore, new cell engineering methods that can efficiently expand and regenerate autologous LSCs in a xenobiotic-free system are dearly needed to achieve acceptable clinical outcome and offer stem-cell based therapy to patients with this devastating blinding diseases in the United States. The first goal of this proposed translational research is to establish a xenobiotic-free culture system by replacing the mouse feeder cells with a human feeder system to expand sufficient amount of LSCs for transplantation. This will allow immediate initiation of clinical trial. We will then further optimized the expansion efficiency by modulating the Wnt and Notch signaling pathways based on our findings that Wnt and Notch signaling regulate the proliferation and differentiation of corneal epithelial cells. In parallel, transdifferentiation of human skin epithelial stem cells to corneal epithelial cells will be induced using a similar approach. The ability and safety of these regenerated human corneal epithelial stem cells to reconstruct the ocular surface will be tested in a LSCD animal model. The results of this proposed study will pave the way for preclinical development of this novel cell engineering technique.
Statement of Benefit to California: 
This proposal is to develop a stem-cell based transplantation therapy for treating a blinding corneal disorder, limbal stem cell deficiency (LSCD). Corneal diseases are the second leading cause of treatable blindness in the world and over 3.2 million people worldwide are bilateral blind from corneal diseases. LSCD has been recognized as a major cause, either primary or secondary, of significant visual loss and blindness in many common corneal disorders, such as chemical/thermal burn, keratopathy related to contact lens wear, and severe infection and inflammation. Due to visual impairment, LSCD patients lose the ability to drive, read, and watch TV. In addition, they would experience recurrent corneal erosion that causes severe pain and sensitivity to light. Frequent break down of the corneal surface increases the risk of infection that requires frequent medical interventions. All of these can also exert psychological impact to the patients and their family members. Therefore, LSCD imposes significant social and economical impact on our society. California is the most populated state in the US. There are more than 36 million people in the State of California and the population will increase to 46 million in 2030. Accordingly, the number of residents with limbal stem cell deficiency is likely disproportionately elevated due to the environmental risk factors. Thus, this disease affects a large population of patients in the state of California. A new treatment to restore vision would represent an important benefit to the people of California. Further, the project would train new stem-cell researchers and advance innovative technology in stem cell therapy. This technology has application to other stem-cell related diseases. When this project enters the clinical phase, it will bring together new physicians and scientists and attract funding by the federal government. In addition, it will undoubtedly attract biotechnology investment in California. The stem-cell based transplantation to treat a stem-cell related disease like limbal stem cell deficiency is well-aligned with the broad mission of CIRM and the objectives of the Early Translational Research Award program.
Progress Report: 
  • Over last year, our research team has made significant progress in achieving our research goals and reaching the appropriate milestones. We first have demonstrated that we are able to grow the human limbal stem cells under the standard method using mouse 3T3 cells as feeder at the same efficiency level as the leading group in the world. This is the first milestone that we have reached.
  • We then proceeded with the initial testing of all the proposed human feeder candidates for their ability to support the growth of human limbal stem cells. We found that the current standard culture method on 3T3 cells did not work for human feeder cells. We then investigated four new culture methods to maximize the growth of limbal epithelial cells on human feeder candidates. We also have included a new human feeder cell candidate, adipose-derived mesenchymal stem cells. We are very excited to find that two of the human feeder cell types could support the growth of limbal epithelial cells with a significantly higher efficiency than the 3T3 cells using our two new culture methods. We are in the process of further refining the culture methods and characterize the expanded limbal epithelial cells. We believe that we are able to establish a xenobiotic free culture system to efficiently expand limbal stem cells for transplantation.
  • The goal of the project is to establish a xenobiotic-free culture system that can efficiently expand human limbal stem cells (LSCs) for transplantation. We have met all of the milestones and have accomplished the following:
  • 1) We can grow LSCs on 3T3 feeder cells (the current gold standard culture method) in our laboratory as efficiently as those described in the literature.
  • 2) We have established two cell carrier systems for transplantation.
  • 3) We have established four 3T3 feeder-free culture methods, including a feeder-free system to expand human LSCs as efficiently as the 3T3 feeder cells do. Three types of human feeder cells— limbal fibroblasts, bone marrow-derived mesenchymal stem cells, and adipose-derived mesenchymal stem cells—support the growth of LSCs. All of the 3T3 feeder-free cultures contain more than 3% of p63bright cells.
  • 4) We have shown that two Wnt small molecule activators can increase the expansion efficiency of LSCs by more than 125%.
  • 5) A nude mouse model of LSC deficiency (LSCD) has been established to test the in vivo function of cultured human LSCs.
  • In addition to reaching these milestones, we have derived a novel method in which feeder cells are completely separated from LSCs during culture. This novel method eliminates contamination by the feeder cells but maintains close contact between them. We have found that trypsin has detrimental effects on LSCs during isolation. Limbal epithelial cells in clusters/sheets and limbal tissue explant culture are superior to single-cell culture for the expansion of LSCs. We will continue to investigate which of the four 3T3 feeder-free systems is the most efficient in expanding the LSC population, and we will continue to refine the LSCD animal model. Before the end of the award period, we will be able to select the most efficient and consistent xenobiotic-free method of cell culture and start regulatory tests that are necessary for submission of an investigational new drug (IND) application to the FDA so that we can begin the first clinical trial to treat patients with unilateral LSCD in California.
  • During the last six months, my laboratory has successfully established a xenobiotic-free and feeder-free culture method to efficiently expand human corneal epithelial stem cells in culture by removing the feeder cells and replacing the fetal bovine serum with human serum. The amount of stem cells produced using this method is comparable to the standard culture method using mouse 3T3 cells as feeder cells and fetal bovine serum. We also have tested the feasibility of using fibrin gel and amniotic membrane as cell carrier and found that amniotic membrane is superior to fibrin as cell carrier. We are establishing an animal model to test the disease modifying effects of these cultivated stem cells. Lastly, we can increase the limbal stem cell expansion efficiency by modulating the Wnt and Notch signaling pathway.

Development of a Stem Cell-based Transplantation Strategy for Treating Age-related Macular Degeneration

Funding Type: 
Early Translational I
Grant Number: 
TR1-01272
ICOC Funds Committed: 
$5 503 069
Disease Focus: 
Vision Loss
Stem Cell Use: 
Adult Stem Cell
iPS Cell
oldStatus: 
Closed
Public Abstract: 
Age related macular degeneration (AMD) is a blinding disease of the elderly affecting nearly one in three individuals over the age of 75. Central vision is lost in AMD, severely impairing the ability to read, watch television, or drive. The epicenter of AMD is the retinal pigment epithelium (RPE), a single layer of cells in the retina adjacent to the photoreceptor cells. A recent breakthrough in AMD research showed that this disease is caused in about 50% of cases by the innate immune system (complement system) inappropriately attacking RPE cells. Specifically, AMD results when regulators of the complement system, which normally protect the RPE, are weakened by mutations. This sickens and later kills the RPE, causing secondary degeneration of photoreceptors in the central retina (macula). The goal of this proposal is to develop a strategy for transplanting stem-cell derived RPE cells into the eyes of patients with AMD. In the past, transplantation of RPE cells from postmortem donors yielded encouraging initial therapeutic effects that subsequently failed due to immune rejection. Current stem-cell technology offers the opportunity to avoid this complication. We plan to generate functional RPE cells from stem cells of the ciliary margin zone (CMZ) in the eye, or pluripotent stem cells induced from skin fibroblasts (iPS cells) taken from the same AMD patient who will later receive the induced RPE cells as a transplant. The study of inherited blindness has benefited greatly from mouse genetic models, where new potential therapies can be tested and developed. One aim of this proposal is to produce RPE cells from mouse and human CMZ- and iPS-cell precursors. To establish that these cells are functional, we will test for two hallmarks of a fully differentiated RPE: (i) the ability to convert vitamin A into visual chromophore for photoreceptor-opsin pigments, and (ii) the ability to phagocytose photoreceptor outer-segments. In a later aim we will transplant these induced RPE cells into the eyes of two genetic “knockout” mice that lack the ability to synthesize visual chromophore. We will test for rescue of the biochemical defects, and correction of the blindness in these mutant mice. In another experiment, we will add to the induced RPE cells a gene that protects from inappropriate complement activation. These cells will be transplanted into the eyes of two other knockout mouse-models of AMD that exhibit abnormal activation of the complement system. We will study these mice to establish correction of the immune defect. Finally, we will test the safety of CMZ- and iPS-derived RPE cells by transplanting them into immune-deficient mice to confirm no tumor formation. At the end of the grant period, we expect to have a new and well-tested stem-cell based transplantation strategy that will be ready for phase-one clinical trials in AMD patients.
Statement of Benefit to California: 
This proposal is to develop a stem-cell based transplantation approach for treating age-related macular degeneration (AMD). AMD is a severe and common disease of the elderly that causes central blindness. The prevalence of AMD increases with advancing age. By 75 years, approximately one in three individuals have some degree of visual loss due to AMD. Thus AMD is significantly more prevalent than Alzheimer disease. Patients with AMD lose the ability to drive, read, watch TV, and recognize faces. With advancing visual impairment, AMD patients lose the ability to care for themselves and others. Thus, AMD imposes a large social and economic burden on our society. As the population in California ages, this burden is expected to increase. The stem-cell based transplantation strategy in this proposal offers the real potential of slowing or arresting the progression of blindness in AMD patients. This alone would represent an important benefit to the people of California. Further, the project would advance innovative technology in stem cell therapy. This technology has application to other neurodegenerative diseases. The project will train new stem-cell researchers in California. As the project enters the clinical phase, it will engage new scientists and physicians and attract funding by the federal government. Further, the opportunity to treat a hugely prevalent disease like AMD will undoubtedly attract biotechnology investment in California. This stem-cell based transplantation approach to treat a major disease like AMD is well-aligned with the broad mission of CIRM and the objectives of the Early Translational Research Award program.
Progress Report: 
  • The broad goal of this project is to develop a stem-cell derived replacement for RPE cells in the eye that die in patients with age-related macular degeneration (AMD). Since RPE cells are often genetically defective in AMD, we will correct this defect in the stem-cell derived RPE cells before transplanting them into patients. These transplanted cells will express specific proteins that will protect them from being attacked by the innate immune system. During the first year of funding we made excellent progress toward this goal. We learned how to generate RPE cells from mouse and human stem cells of various sources. We prepared all the DNA constructs that will be required to protect the transplanted RPE cells from attack by the innate immune system. We also developed a new approach for injecting RPE cells into the correct part of the mouse eye (subretinal space) without damaging other parts of the retina. We are enthusiastic to continue our work on this exciting project.
  • The broad goal of this project is to develop a stem-cell derived replacement for retinal pigment epithelial (RPE) cells in the eye, which die in patients with age-related macular degeneration (AMD). Since RPE cells are often genetically defective in AMD, we will correct this defect in the stem-cell derived RPE cells before transplanting them into patients. These transplanted cells will express specific proteins that will protect them from being attacked by the innate immune system. During our second year of funding, we transplanted human stem-cell derived RPE cells into the eyes of mice that are blind due to a genetic defect in the rpe65 gene. We showed that the human cells integrated into the RPE layer of these mice. Further, we demonstrated that the transplanted cells partially rescued the blindness in rpe65 / mice. We also generated and tested the recombinant viruses that will protect RPE cells from attack by the innate immune system. We are on schedule to complete the planned studies for this project during the final year of funding.
  • This project is to develop a new treatment for age-related macular degeneration (AMD) based on transplantation of retinal pigment epithelial (RPE) cells into the subretinal space of a patient’s eyes. These RPE cells are induced from stem cells collected from the same patient, to avoid the problem of immune rejection. AMD is primarily an inflammatory disorder caused by inappropriate attack of RPE cells by the complement system. Accordingly, negative regulators of complement activation will be expressed in the stem-cell derived RPE cells by viral transduction. We explored two sources of stem cells that can be collected from a patient: embryonic stem cells and induced pluripotent stem (iPS) cells from skin fibroblasts. We successfully programed these stem cells into fully functional RPE cells. Our team has extensive experience with the biochemistry and cell biology of the RPE. We used “knockout” mouse models with mutations in RPE genes to test the efficiency of RPE-cell transplantation. Next, we planned to test the strategy of protecting RPE cells from complement attack by over-expressing complement negative-regulatory factors. We tested the long-term viability of induced RPE cells, and rule-out tumorgenicity by transplanting these cells into the eyes of severe-combined immunodeficient mice.

Autologous Retinal Pigmented Epithelial Cells Derived from Induced Pluripotent Stem Cells for the Treatment of Atrophic Age Related Macular Degeneration

Funding Type: 
Early Translational I
Grant Number: 
TR1-01219
ICOC Funds Committed: 
$5 945 738
Disease Focus: 
Aging
Vision Loss
Stem Cell Use: 
iPS Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Closed
Public Abstract: 
The leading cause of visual loss in Americans over the age of 65 is age related macular degeneration (AMD) which occurs in both a "wet" and a "dry" form. Both forms of the disease are associated with loss of cells called retinal pigmented epithelium (RPE) which can lead to profound loss of central vision. Currently, there is no treatment that will reverse or prevent the loss of these cells and associated blindness. Nutritional supplementation with antioxidants, macular pigments and long chain PUFAs was shown to slightly reduce disease progression but the clinical reality is that 6-8% of people over the age of 75 are legally blind from this disease. Others have observed that RPE cells can be obtained from human embryonic stem cells and that these cells may be transplanted into eyes of animals with diseases that resemble human macular degeneration with RPE dysfunction. Potential problems with this approach to treating humans with this disease include the possibility that the embryonic stem cells from which the RPE are derived may be carried over into the eye and form tumors or elicit an immune response in the recipient eye since the cells are not from the same individual receiving the transplant. Recent advances in stem cell biology now make it possible to induce the formation of pluripotent stem cells (iPSC) from adult, or somatic, tissues of individuals; these cells, in turn, may be stimulated to form RPE cells. Thus, it would be possible to produce RPE cells from the skin or hair of the same individual who would receive the transplant. In order to do this, current technology requires the use of lentiviral vectors that integrate into the genetic material of the recipient cells. In addition, the efficiency with which the iPSC are formed is not very high and to produce these cells, and the derived RPE cells, it is necessary to use "feeder" cell layers and molecules derived from animals. In this research proposal, we will take advantage of novel chemistries and molecular biological techniques to develop iPSC from somatic tissues of patients with AMD and produce RPE cells that could then be used to replace damaged tissue in these patients' eyes. Using small molecules obtained from unique chemical libraries, we will enhance the efficiency of iPSC and RPE production from somatic cells and eliminate the use of animal cell "feeder" layers and supplements. Furthermore, we will use a unique procedure ("an episomal vector") to produce iPSC from somatic cells that does not require the use of potentially dangerous viruses and permanently integrated genetic material. If we are successful, a patient with early signs of AMD could come into their ophthalmologist's office, have a skin biopsy performed that could be used to obtain RPE cells that could then be transplanted into that individual's eye at a later date when their own RPE begin to degenerate, but before they have visual loss.
Statement of Benefit to California: 
As the population ages, individuals are prone to develop diseases of aging that significantly impact the quality of life in the "golden years." Foremost among these diseases is age related macular degeneration (AMD), a disease that affects the tissue in the back of the eye (the retina) used for vision. The central portion of this tissue, called the macula, is most affected in AMD and can lead to loss of fine, or "reading", vision. Vision loss occurs from two principal forms of the disease; the "wet" type involving the abnormal growth of new blood vessels and the "dry" type, involving degeneration and scarring of the macula. In both forms, special types of cells under the retina, called retinal pigmented epithelial (RPE) cells degenerate and contribute to the loss of vision. It is estimated that 15-20 million Americans over the age of 65 have AMD and 10-15% of these have vision loss secondary to the disease. Geographic atrophy (the dry type) affects 0.81% of the US population, equivalent to a prevalence of approximately 300,000 in California. Another 6.12% of the population (2.2 million Californians) suffer from early-stage AMD which puts them at high risk for developing geographic atrophy within 5 years. Currently there are some drugs available to help a certain portion of patients with the "wet" form of the disease, but there are no treatments for the "dry" or atrophic, form of the disease. We propose the use of transplants of healthy RPE cells into the eyes of patients with the atrophic form of AMD; these cells would be derived from the patients own skin or hair cells after inducing the production of pluripotent stem cells which could then be stimulated to become RPE cells. If successful, this approach would potentially provide a treatment for the leading cause of vision loss in Californians over the age of 65 with cells derived from their own tissue, avoiding potential complications associated with (1) repeated injections into the eye, (2) using cells from animals or other individuals and (3) deriving cells for transplant that have been exposed to animal cells or molecules and viral genetic material. Preserving vision in the elderly population not only would immensely improve the quality of life for these individuals, but it would also greatly facilitate their ability to function independently and productively.
Progress Report: 
  • The recent development of technologies capable of producing induced pluripotent stem (iPS) cells from adult somatic tissues may permit their use to generate autologous retinal pigment epithelium (RPE) grafts for the treatment of diseases like age-related macular degeneration. However, conventional reprogramming techniques are based on random genomic integration of four transcription factors with oncogenic potential. To minimize the risk of tumor formation, the use of iPS cells reprogrammed with a reduced number of these factors would be advantageous. We therefore evaluated the differentiation capacity of iPS cells generated from primary human epidermal keratinocytes by lentiviral transduction with only two or one factor (Oct4 and Klf4 or Oct4 only, respectively) and additional treatment with small molecules. Human iPS cells reprogrammed by conventional methods were used for comparison. Four factor-, two factor-, and one factor-derived iPS cells could be differentiated into cells that expressed RPE-specific markers (e.g., bestrophin, CRALBP, RPE65, tyrosinase). Moreover, these cells exhibited morphological and functional features characteristic of RPE cells such as formation of epithelial monolayers with intercellular tight junctions, homogenous polygonal morphology, pronounced pigmentation, phagocytosis of photoreceptor outer segments, and vectorial apical-to-basolateral fluid transport. Furthermore, we have demonstrated that the 1-factor iPSC-derived RPE cells, when injected into a rodent model of atrophic macular degeneration, could establish grafts of RPE and prevent the degeneration of photoreceptors (neurons) in this model. Thus, we demonstrate that human iPS cells generated by novel reprogramming techniques can be differentiated into cells with RPE-specific morphology, gene/protein expression and function. Compared to conventional iPS cells, these cells may be superior for clinical application due to the elimination of oncogenic reprogramming factors and, ultimately, retroviral transfection vectors.
  • The recent development of technologies capable of producing induced pluripotent stem (iPS) cells from adult somatic tissues may permit their use to generate autologous retinal pigment epithelium (RPE) grafts for the treatment of diseases like age-related macular degeneration. However, conventional reprogramming techniques are based on random genomic integration of four transcription factors with oncogenic potential. To minimize the risk of tumor formation, the use of iPS cells reprogrammed with a reduced number of these factors would be advantageous. We therefore evaluated the differentiation capacity of iPS cells generated from primary human epidermal keratinocytes by lentiviral transduction with only two or one factor (Oct4 and Klf4 or Oct4 only, respectively) and additional treatment with small molecules. Human iPS cells reprogrammed by conventional methods were used for comparison. Four factor-, two factor-, and one factor-derived iPS cells could be differentiated into cells that expressed RPE-specific markers (e.g., bestrophin, CRALBP, RPE65, tyrosinase). Moreover, these cells exhibited morphological and functional features characteristic of RPE cells such as formation of epithelial monolayers with intercellular tight junctions, homogenous polygonal morphology, pronounced pigmentation, phagocytosis of photoreceptor outer segments, and vectorial apical-to-basolateral fluid transport. Furthermore, we have demonstrated that the 1-factor iPSC-derived RPE cells, when injected into a rodent model of atrophic macular degeneration, could establish grafts of RPE and prevent the degeneration of photoreceptors (neurons) in this model. Thus, we demonstrate that human iPS cells generated by novel reprogramming techniques can be differentiated into cells with RPE-specific morphology, gene/protein expression and function. Compared to conventional iPS cells, these cells may be superior for clinical application due to the elimination of oncogenic reprogramming factors and, ultimately, retroviral transfection vectors.
  • The recent development of technologies capable of producing induced pluripotent stem (iPS) cells from adult somatic tissues may permit their use to generate autologous retinal pigment epithelium (RPE) grafts for the treatment of diseases like age-related macular degeneration. However, conventional reprogramming techniques are based on random genomic integration of four transcription factors with oncogenic potential. To minimize the risk of tumor formation, the use of iPS cells reprogrammed with a reduced number of these factors would be advantageous. We therefore evaluated the differentiation capacity of iPS cells generated from primary human epidermal keratinocytes by lentiviral transduction with only two or one factor (Oct4 and Klf4 or Oct4 only, respectively) and additional treatment with small molecules. Human iPS cells reprogrammed by conventional methods were used for comparison. Four factor-, two factor-, and one factorderived iPS cells could be differentiated into cells that expressed RPE-specific markers (e.g., bestrophin,CRALBP, RPE65, tyrosinase). Moreover, these cells exhibited morphological and functional features characteristic of RPE cells such as formation of epithelial monolayers with intercellular tight junctions, homogenous polygonal morphology, pronounced pigmentation, phagocytosis of photoreceptor outer segments, and vectorial apical-to-basolateral fluid transport. Furthermore, we have demonstrated that the 1-factor iPSC-derived RPE cells, when injected into a rodent model of atrophic macular degeneration, could establish grafts of RPE and prevent the degeneration of photoreceptors (neurons) in this model. Thus, we demonstrate that human iPS cells generated by novel reprogramming techniques can be differentiated into cells with RPE-specific morphology, gene/protein expression and function. Compared to conventional iPS cells, these cells may be superior for clinical application due to the elimination of oncogenic reprogramming factors and, ultimately, retroviral transfection vectors.
  • The recent development of technologies capable of producing induced pluripotent stem (iPS) cells from adult somatic tissues may permit their use to generate autologous retinal pigment epithelium (RPE) grafts for the treatment of diseases like age-related macular degeneration. However, conventional reprogramming techniques are based on random genomic integration of four transcription factors with oncogenic potential. To minimize the risk of tumor formation, the use of iPS cells reprogrammed with a reduced number of these factors would be advantageous. We therefore evaluated the differentiation capacity of iPS cells generated from primary human epidermal keratinocytes by lentiviral transduction with only two or one factor (Oct4 and Klf4 or Oct4 only, respectively) and additional treatment with small molecules. Human iPS cells reprogrammed by conventional methods were used for comparison. Four factor-, two factor-, and one factorderived iPS cells could be differentiated into cells that expressed RPE-specific markers (e.g., bestrophin,CRALBP, RPE65, tyrosinase). Moreover, these cells exhibited morphological and functional features characteristic of RPE cells such as formation of epithelial monolayers with intercellular tight junctions, homogenous polygonal morphology, pronounced pigmentation, phagocytosis of photoreceptor outer segments, and vectorial apical-to-basolateral fluid transport. Furthermore, we have demonstrated that the 1-factor iPSC-derived RPE cells, when injected into a rodent model of atrophic macular degeneration, could establish grafts of RPE and prevent the degeneration of photoreceptors (neurons) in this model. We have completed a study of the long-term effects of these cells injected into rodent eyes and observe continued trophic rescue effects and lack of any adverse events for up to two years post-injection. Thus, we demonstrate that human iPS cells generated by novel reprogramming techniques can be differentiated into cells with RPE-specific morphology, gene/protein expression and function. Compared to conventional iPS cells, these cells may be superior for clinical application due to the elimination of oncogenic reprogramming factors and, ultimately, retroviral transfection vectors.

Therapeutic potential of Retinal Pigment Epithelial cell lines derived from hES cells for retinal degeneration.

Funding Type: 
SEED Grant
Grant Number: 
RS1-00222
ICOC Funds Committed: 
$684 322
Disease Focus: 
Aging
Vision Loss
Stem Cell Use: 
Embryonic Stem Cell
oldStatus: 
Closed
Public Abstract: 
Retinal degeneration represents a group of blinding diseases that are increasingly impacting the health and well being of Californians. It is estimated that by 2020, over 450,000 Californians will suffer from vision loss or blindness due to the age-related macular degeneration (AMD), the most common cause of retinal degeneration diseases in the elderly. Furthermore, retinitis pigmentosa is the leading cause of inherited blindness in younger people. Currently there are no cures for these diseases. A layer of cells at the back of the eye called the retinal pigment epithelium (RPE), provide support, protection, and nutrition to the light sensitive retina, and cooperate with other retinal cells to maintain normal visual function. The dysfunction and/or loss of these RPE cells play a critical role in the development of the previously described blinding diseases. We suggest that effective treatment of retinal degeneration could be achieved by the proper replacement of damaged RPE and retinal cells with healthy ones. However, lack of the reasonable supply of healthy human eye cells hampers the application of this therapeutic approach. Recent advances in knowledge and technology of embryonic stem cells brings new hope for the development of cell replacement treatment. Embryonic stem (ES) cells are capable of unlimited self-replication and production of different cell types. RPE cells derived from human ES cells (hES-RPE) are a potentially unlimited resource for the cell replacement approach. We hypothesize that the dysfunction and/or loss of RPE can be replenished and restored through the transplantation of functionally polarized RPE monolayers derived from human embryonic stem cells, and this transplantation can cure the retinal degeneration diseases caused by RPE dysfunction.We propose to: 1. Derive RPE cells from human ES cells; 2. Establish and characterize the functionally mature or polarized monolayer of hES-RPE cells that will be suitable for transplantation; 3. Rescue the retinal degeneration phenotype through the transplantation of functionally mature or polarized monolayer of hES-RPE cells in animal models. Our goal is to determine the feasibility of treating the retinal degeneration diseases caused by RPE dysfunction through the transplantation of a monolayer of polarized hES-RPE cell sheet. The knowledge and technology from our research can be used to develop new treatments for human retinal degeneration diseases.
Statement of Benefit to California: 
Age-related macular degeneration (AMD) is the leading cause of severe vision loss or blindness among the elderly, and currently no cure for this disorder exists. Based on the fact that California is the most populated state, and that the population continues to age, it is estimated that over 450,000 of Californians will suffer from AMD with severe vision impairment by 2020. Studies have shown that the devastating consequences of AMD include the progressive loss of independence and productivity, and increased risks of falls, fractures, and depression among diseased population. So this is not only a problem of the individual quality of life, but also an issue of increasing public health burden and concern. In this study we will test the feasibility of treating AMD and other retinal degenerative diseases through the transplantation of human embryonic stem cells that have been treated to differentiate into retinal pigment epithelial cells (RPE); the cells known to primarily degenerate or die in AMD. If our experimentation with RPE replacement therapy is successful in animal models, the knowledge and techniques can be quickly used to develop novel treatments for human diseases. Hundreds of thousands of Californians with AMD and other retinal degeneration diseases could benefit from our research for better quality of life with reduced morbidity. The California economy may significantly benefit from this work through potential reduced costs for health care, social welfare, and the loss of labor force.
Progress Report: 
  • It is estimated that by 2020, over 450,000 Californians will suffer from vision loss or blindness due to the age-related macular degeneration (AMD), the most common cause of retinal degeneration in the elderly. A layer of cells at the back of the eye called the retinal pigment epithelium (RPE), provides support, protection, and nutrition to the light sensitive retina, and cooperates with other retinal cells to maintain normal visual function. The dysfunction and/or loss of these RPE cells play a critical role in the development of dry AMD, the most common form of that disease. RPE cells derived from human ES cells (hES-RPE) are a potentially unlimited resource for cell replacement therapy.
  • During this grant period we were able to develop methods to reproducibly derive RPE cells from established human ES (hES) cell lines.
  • Normal RPE cells have a polarized appearance, meaning that they have specialized appearances and functions on the top (retinal facing) and bottom of the cells. We were then able to induce the hES-derived RPE to develop a polarized appearance very similar to that found in the normal eye. These cells had specialized characteristics that were remarkable similar to normal RPE and showed ability to function like normal RPE cells. We then developed sheets of hES-derived RPE on substrates that could be used for surgical implantation into animal eyes.
  • We then performed studies to establish appropriate animal models in which to test the ability of hES-derived RPE to prevent or slow retinal degeneration in animal models that have some features of human AMD. We were not able to use standard mouse models of AMD because mouse eyes are too small to perform the surgical implantation of polarized RPE. We first looked at a rabbit model of RPE degeneration induced by a toxin (sodium iodate). We were able to establish reproducible RPE degeneration in these animals but whenever we tried to implant hES-derived RPE under the retinas of these animals, the RPE cells did not survive. We believe that the toxin that was used to induce this model was being taken up by the transplanted cells resulting in their death. We then tested a genetic model of retinal degeneration in rats (RCS rat). We were able to demonstrate reproducible retinal degeneration in these animals. When we transplanted hES-derived RPE under the retinas of these animals, we were able to show that the RPE were indeed human in origin and that they were able to survive for at least several weeks after transplantation. Importantly, we were able to show that in the areas where hES-derived RPE were transplanted, there was less retinal degeneration than in the areas in which there was no transplantation or "sham" transplantation.
  • Thus, in conclusion, we were able to show (1) the reproducible culture of RPE cells from human ES cell lines, (2) that these hES-derived RPE had the appearance and functional characterisitics of human RPE and could be grown on substrates as sheets or polarized cells, and (3) that when these sheets of polarized hES-derived RPE were implanted under the retinal of rats with retinal degeneration, that they were able to survive and showed the ability to slow the progression of retinal degeneration in these animals.
  • The results of this study suggest that hES cells may be an unlimited source of RPE cells suitable for transplantation into eyes with retinal degeneration and that subretinal implantation of polarized hES-derived RPE may represent a novel therapy for dry AMD.

Development of Cellular Therapies for Retinal Disease

Funding Type: 
Research Leadership 2
Grant Number: 
LA1_C2-02086
ICOC Funds Committed: 
$4 880 116
Disease Focus: 
Vision Loss
Stem Cell Use: 
Embryonic Stem Cell
iPS Cell
Cell Line Generation: 
iPS Cell
oldStatus: 
Active
Public Abstract: 
The long term goal of our research program is regeneration of the diseased eye. Age-related macular degeneration, diabetic retinopathy, and retinitis pigmentosa are leading causes of blindness for which there are no effective treatments for the majority of cases. Loss of vision is due to progressive degeneration of the photoreceptor cells, or loss of cells that support the photoreceptors, such as retinal pigment epithelial (RPE) cells or cells in the retinal blood vessels. The RPE is a pigmented cell layer that lies just behind the retinal and is necessary for photoreceptor survival. One possible strategy for treatment of these blinding diseases is to replace cells that are lost via transplantation. My work explores this approach, with the object of first identifying and characterizing sources of cells, determining the optimal parameters for transplantation, and investigating molecular, cellular and behavioral events that occur upon transplantation in animal models of retinal degeneration. In the case of age-related macular degeneration, there is a solid body of evidence that RPE cell loss is often an early event in disease progression. We have shown that RPE can be derived from human embryonic stem cells (hESC) and induced pluripotent stem cells (iPSC), and they can rescue vision in rodent and pig models of retinal dystrophy. We have joined forces with interdisciplinary teams in the UK and California to transition this work to the clinic, using RPE derived from hESC. We will also investigate other forms of RPE-based eye disease by generating iPSC from patients, differentiating them to RPE, and analyzing function. Small molecules that are candidate drugs will then be screened for functional rescue. In the case of diabetic retinopathy, we are investigating a strategy to used hESC-derived cells to repair blood vessels. Finally, in retinitis pigmentosa, we will pursue a possible route to replace photoreceptors by converting the surviving retinal ganglion cells into light sensing cells. The aim of the proposed studies is to provide foundational knowledge that will enable and guide further translation of cellular therapies to improve vision in patients.
Statement of Benefit to California: 
Age-related macular degeneration (AMD), retinitis pigmentosa (RP) and diabetic retinopathy are leading causes of vision loss and blindness. Because California is the most populous state in the nation, and because the elderly constitute a greater percentage of its population, it is estimated that over 450,000 of Californians will suffer from AMD with severe vision impairment by 2020, leading to huge costs. Diabetes continues to be a major health concern, with vision loss a common outcome. Moreover, the devastating consequences of vision deficits include the progressive loss of independence and productivity, and increased risks of falls, fractures, and depression among diseased population. So this is not only a problem of the individual quality of life, but also an issue of increasing public health burden and concern. Clearly, there is a need for better treatments. In these diseases, loss of vision is due to progressive degeneration of the light sensitive photoreceptor cells of the eye or defects in the supporting cells of the eye, including the retinal pigmented epithelium (RPE). There is now a solid body of evidence that suggests that RPE degeneration is the first step in AMD. There is no cure for these conditions at present, although studies of model experimental animals, mostly rats and mice, suggest several possible routes to therapy. One of these involves the transplantation of cells to slow the degeneration of photoreceptors by replacing key support cells lost during degeneration. My work explores this approach with the object of first identifying and characterizing sources of ocular cells, determining the optimal parameters for transplantation, and identifying molecular and cellular and behavioral events that occur upon transplantation in animal models of retinal degeneration. One source of cells for transplantation is ocular cells derived from human embryonic stem cells (hESC) or induced pluripotent stem cells (iPSC). We have shown that ocular cells, especially RPE, can be derived from both hESC and iPSC, and they can rescue visual function in rodent models of retinal dystrophy. We have shown that RPE can be derived from both hESC and iPSC, and they can rescue visual function in rodent models of retinal dystrophy. We have teamed up with an interdisciplinary disease team of stem cell biologists, materials chemists, neuroscientists, and retinal surgeons to transition this work towards clinical application for AMD, using hESC to produce RPE. Other research aims are to generate specific blood vessel cells from stem cells to replenish the retinal blood vessels in diabetic retinopathy, to generate new photosensitive cells to restore vision, and to use iPSC derived from patients to understand retinal disease and identify novel treatments. California patients with vision loss will benefit greatly from the studies proposed.
Progress Report: 
  • The goal for the first year was to establish a totally new laboratory from the ground up at the recently opened new UC Santa Barbara Center for Stem Cell Biology and Engineering funded by CIRM. This involved equipping the whole laboratory from small to large equipment items. This was made possible by the recruitment of three excellent scientists: a senior scientist, a research technician and a PhD student. This enabled the laboratory to quickly get established and running some initial experiments to ensure processes were working. We have run a number of preliminary experiments the results of which will be presented at conference later this year. The goal of the initial experiments was to establish techniques to improve cell transplantation for eye diseases.
  • The foundation of this project is built on the premise of cell therapies for age-related macular degeneration (AMD). AMD is a disease of failed and eventually aberrant wound repair. In its early phase, it is characterized by the formation and accumulation of debris in the back of the eye that can act as barriers to normal function and lead to activation of an immune response. While the nature of the insult that initiates this response is not fully understood, it may in part be due to cumulative wear and tear that results in oxidative or physical damage to eye. Whatever the origin, the response only serves to cause further damage and disease progression. Eventually, a tipping point is reached that triggers a switch that leads to the transition to the advanced forms of AMD characterized by cell death and and scaring. The aim of the second year is to understand this wound response and change using stem cell based models.

Stem cell based treatment strategy for Age-related Macular Degeneration (AMD)

Funding Type: 
Disease Team Research I
Grant Number: 
DR1-01444
ICOC Funds Committed: 
$18 904 916
Disease Focus: 
Vision Loss
Collaborative Funder: 
UK
Stem Cell Use: 
Embryonic Stem Cell
Cell Line Generation: 
Embryonic Stem Cell
oldStatus: 
Active
Public Abstract: 
Retinal degeneration represents a group of blinding diseases that are increasingly impacting the health and well being of Californians. It is estimated that by 2020, over 450,000 Californians will suffer from vision loss or blindness due to the age-related macular degeneration (AMD), the most common cause of retinal degeneration diseases in the elderly. AMD is a progressive ocular disease of the part of the retina, called the macula, which enables people to read, visualize faces, and drive. The disease initially causes distortion in central vision, and eventually leads to legal blindness. A layer of cells at the back of the eye called the retinal pigment epithelium (RPE), provide support, protection, and nutrition to the light sensitive cells of the retina; the photoreceptors which consist of rods and cones . The dysfunction and/or loss of these RPE cells play a critical role in the loss of the PR’s and hence the blindness in AMD. Effective treatment could be achieved by proper replacement of damaged RPE and retinal cells with healthy ones. More specifically, the regenerated and restored RPE layer would prevent the irreversible loss of the PR’s. However, the lack of a feasible approach to restore the RPE cells has prevented the realization of a potential therapy. Recent advances in knowledge and technology of human embryonic stem (hES) cells brings new hope for the development of cell replacement treatment. hES cells are capable of unlimited self-replication and production of different cell types. RPE cells derived from hES cells are a potentially unlimited and robust source for regenerating RPE. We hypothesize that the dysfunction and/or loss of RPE can be overcome by regenerating and restoring the RPE through the transplantation of functionally polarized RPE monolayers derived from hES cells. Such RPE cells derived from hES can then be transplanted into the eye, using minimally invasive surgical procedures saving the PR from dying. Our group is composed of unique multidisciplinary members who collectively have more than two decades of experience in efforts to restore sight to the blind as well as retinal cell transplantation and stem cell research. Our plan for this grant is to use our expertise and infrastructure to show to the FDA the success of our preclinical tests using hES derived RPE cells in order to get approval to conduct a clinical trial in patients at risk of vision loss due to AMD.
Statement of Benefit to California: 
Age-related macular degeneration (AMD) is the leading cause of vision loss and blindness among the elderly. Based on the fact that California is one of the most populated state in the Unites States (38 million population in 2007), and a greater percentage of its population will be 65 years or older. It is estimated that over 450,000 of Californians will suffer from AMD with severe vision impairment by 2020. Even using National Eye Institute numbers from 2003 and adjusting it for the population of California, the costs for California exceed $8 billion (http://www.nei.nih.gov/eyedata/hu_estimates.asp). Since the introduction of the anti-VEGF drug Lucentis by Genentech in 2006, the cost for the treatment for AMD has even further sky rocketed. For example, the cost of these monthly injections to treat all of the new cases of neovascular (wet) AMD in 2008 in California alone would exceed 9 billion (single patient costs per year often is approximately $25k/year). Moreover, studies have shown that the devastating consequences of AMD include the progressive loss of independence and productivity, and increased risks of falls, fractures, and depression among diseased population. So this is not only a problem of the individual quality of life, but also an issue of increasing public health burden and concern. In this study, we will test the feasibility of treating AMD through the transplantation of human embryonic stem cells that have been treated to differentiate into retinal pigment epithelial cells (RPE); one of the key cell types known to primarily degenerate or die in AMD. The approach of regenerating the RPE cell layer has many advantages over regenerating photoreceptors and is much more likely to be achieved in the near future. The biggest advantage to RPE cell layer regeneration is that it is preventative and protects or rescues the photoreceptors from degenerating. Also, since it is not a neuronal cell line it does not need to form synapses with the host; a much more difficult task. The success of our preclinical experimentation with RPE replacement therapy will be seamlessly and quickly transferred into clinical trials to develop novel treatments for AMD. Ultimately, hundreds of thousands of Californians with AMD would benefit from our research, with improvement in quality of life and reduced morbidity. The California economy will significantly benefit from this work through potential reduced costs for health care and social welfare. We also envision that our research would lead to a new industry and hence many more employment opportunities and also add to the revenue generated by the state of California. Also our efforts at the University level in California would lead to new curricula in stem cells and regenerative medicine and thus educate the work force of the future.
Progress Report: 
  • It is estimated that by 2020, over 450,000 Californians will suffer from vision loss or blindness due to the age-related macular degeneration (AMD), the most common retinal degenerative disease in the elderly. AMD is a progressive ocular disease of the part of the retina at the back of the eye, called the macula, which enables people to read, visualize faces, and drive. The disease initially causes distortion in central vision, and eventually leads to legal blindness.
  • A layer of cells at the back of the eye called the retinal pigment epithelium (RPE)provide support, protection, and nutrition to the light sensitive photoreceptors in the retina. The dysfunction and/or loss of these RPE cells play a critical role in the loss of the PR’s and hence the blindness in AMD. Effective treatment could be achieved by proper replacement of damaged RPE and retinal cells with healthy ones. RPE cells derived from human embryonic stem cells (hESC) are a potentially unlimited and robust source for regenerating RPE (hESC-RPE).
  • During the first year of our Disease Team Grant we have assembled a closely working team of interdisciplinary scientists and physician scientists at the University of Southern California (USC), Doheny Eye Institute (DEI), University of California Santa Barbara (UCSB), California Institute of Technology (Caltech), and City of Hope (COH). Our scientists work and meet together frequently to discuss progress and we have had 2 highly successful full-day retreats; one at USC and one at UCSB.
  • We are on track for each of the Year 1 proposed milestones. During the first year we have made a decision on final selection of hESC line; and have developed protocols for the generation and molecular and functional characterization of hESC-RPE and are transferring these protocols to our manufacturing and regulatory partners at City of Hope. COH has had onsite visits to learn protocols at UCSB and USC and we have had a day-long meeting at COH to further refine protocols and procedures. In collaboration with Caltech we have developed a non-biodegradable substrate on which these cells are grown and where they develop characteristics of mature RPE cells. Specialized surgical instruments have been developed at DEI and Caltech to implant the hESC cells grown on substrate under the retina. We have utilized sophisticated instrumentation to image the retina in live animals and have used these instruments to follow rats with progressive retinal degeneration before and after implantation of the hESC. We have demonstrated that hESC rescue the degeneration and integrate well into the host retina. Sections of these retinas are evaluated histologically at the microscopic level using sophisticated quantitative imaging techniques.
  • Our group is composed of unique multidisciplinary members who collectively have more than two decades of experience in efforts to restore sight to the blind as well as retinal cell transplantation and stem cell research. Our ultimate goal is to submit an Investigational New Drug (IND) Application to the Food and Drug Administration (FDA) by the end of the 4th year of the grant in order to get approval to conduct a clinical trial in patients at risk of vision loss due to AMD.
  • Age-Related Macular Degeneration (AMD) is a devastating disease that can lead to severe vision impairment and blindness. Vision loss in AMD usually is after age 55 and affects almost 2 million Americans.
  • Vision is initiated by light striking and activating specific cells called photoreceptor cells of the neural retina within the eye. There is a small, specialized region in the central portion of the retina called the macula that is particularly important for central, sharp and color vision. It has a high percentage of photoreceptor cells called "cone cells" and it is this region that is most affected by AMD. Thus, with cone cell degeneration in AMD, a person loses their central, sharp vision with color vision affected as well.
  • In the normal retina, photoreceptor cells are supported metabolically and structurally by a thin layer of cells next to them called Retinal Pigment Epithelial (RPE)Cells. Without these RPE cells, photoreceptor cells quickly degenerate and die. In AMD, it is thought that dysfunction of RPE cells is an early and critical sign of AMD. Thus, replacing dead or dying RPE cells in AMD could be a way to slow the disease process and even improve vision.
  • Our CIRM disease team grant which we call The California Project to Cure Blindness aims to treat AMD through replacement of these dysfunctional RPE cells with fresh RPE cells that will then keep photoreceptor cells alive and functioning. Because only very few RPE cells are present in a human eye, direct RPE transplantation would be very difficult so we rely on the use of human embryonic stem cells (hESCs). Through the work in our CIRM funded disease team grant we have been able to use a particular stem cell line and differentiate into adult-like RPE cells that exhibit many characteristics of normal mature human RPE cells. We believe that implanting these hESCs within the eye next to the retina could be of benefit in AMD in saving the photoreceptors.
  • Our technique is to not only implant the hESC derived RPE cells in the eye but to place them on a special ultrathin substrate platform that will maintain them in proper orientation next to the retina. Moreover, implantation can be done with hESC cells that had been allowed to differentiate in tissue culture prior to implantation, insuring that the implanted cells indeed express the characteristics of mature, functional RPE cells.
  • In this last year, substantial progress has been made in progressing to our goal of replenishing RPE cells in the AMD retina and restoring vision. First, a specific hESC line has been identified that will differentiate into cells that have many of the morphological and biochemical characteristics of normal adult RPE cells. Second, an appropriate material has been found that can act as a substratum (platform) that will support the RPE cells and allow them to function in a normal manner. Third, we have begun to demonstrated the safety of our procedure as well as its efficacy in slowing vision loss in a rodent model of retina degeneration. Fourth, we also have developed unique surgical techniques that will allow us to safely and effectively place the cells in the animal and ultimately human eyes.
  • In parallel to these basic studies, we are advancing our strategies that will let us treat human patients with AMD. Clinical protocols are being established that will be submitted to the US FDA to gain their approval in order to start phase 1 (early) Clinical Trial. In summary, our CIRM grant has allowed us to develop a procedure that should let us treat severe vision loss in AMD. Already, data at 6 months in animal studies has demonstrated the safety of the technique as well as the restoration of functional vision in a model system. Hopefully, this will lead us to a successful human clinical trial with sight restoration in currently untreatable cases of dry AMD.
  • Age-Related Macular Degeneration (AMD) is a devastating disease that can lead to severe vision impairment and blindness. Vision loss in AMD usually is after age 55 and affects almost 2 million Americans.
  • Vision is initiated by light striking and activating specific cells called photoreceptor cells of the neural retina within the eye. There is a small, specialized region in the central portion of the retina called the macula that is particularly important for central, sharp and color vision. It has a high percentage of photoreceptor cells called "cone cells" and it is this region that is most affected by AMD. Thus, with cone cell degeneration in AMD, a person loses their central, sharp vision with color vision affected as well.
  • In the normal retina, photoreceptor cells are supported metabolically and structurally by a thin layer of cells next to them called Retinal Pigment Epithelial (RPE)Cells. Without these RPE cells, photoreceptor cells quickly degenerate and die. In AMD, it is thought that dysfunction of RPE cells is an early and critical sign of AMD. Thus, replacing dead or dying RPE cells in AMD could be a way to slow the disease process and even improve vision.
  • Our CIRM disease team grant which we call The California Project to Cure Blindness aims to treat AMD through replacement of these dysfunctional RPE cells with fresh RPE cells that will then keep photoreceptor cells alive and functioning. Because only very few RPE cells are present in a human eye, direct RPE transplantation would be very difficult so we rely on the use of human embryonic stem cells (hESCs). Through the work in our CIRM funded disease team grant we have been able to use a particular stem cell line and differentiate into adult-like RPE cells that exhibit many characteristics of normal mature human RPE cells. We believe that implanting these hESCs within the eye next to the retina could be of benefit in AMD in saving the photoreceptors.
  • Our technique is to not only implant the hESC derived RPE cells in the eye but to place them on a special ultrathin substrate platform that will maintain them in proper orientation next to the retina. Moreover, implantation can be done with hESC cells that had been allowed to differentiate in tissue culture prior to implantation, insuring that the implanted cells indeed express the characteristics of mature, functional RPE cells.
  • In this last year, substantial progress has been made in progressing to our goal of replenishing RPE cells in the AMD retina and restoring vision. First, a specific hESC line has been identified that will differentiate into cells that have many of the morphological and biochemical characteristics of normal adult RPE cells. Second, an appropriate material has been found that can act as a substratum (platform) that will support the RPE cells and allow them to function in a normal manner. Third, we have begun to demonstrated the safety of our procedure as well as its efficacy in slowing vision loss in a rodent model of retina degeneration. Fourth, we also have developed unique surgical techniques that will allow us to safely and effectively place the cells in the animal and ultimately human eyes.
  • In parallel to these basic studies, we are advancing our strategies that will let us treat human patients with AMD. Clinical protocols are being established that will be submitted to the US FDA to gain their approval in order to start phase 1 (early) Clinical Trial. In summary, our CIRM grant has allowed us to develop a procedure that should let us treat severe vision loss in AMD. Already, data at 6 months in animal studies has demonstrated the safety of the technique as well as the restoration of functional vision in a model system. Hopefully, this will lead us to a successful human clinical trial with sight restoration in currently untreatable cases of dry AMD.
  • Age-Related Macular Degeneration (AMD) is a devastating disease that can lead to severe vision impairment and blindness. Vision loss in AMD usually is after age 55 and affects almost 2 million Americans.
  • Vision is initiated by light striking and activating specific cells called photoreceptor cells of the neural retina within the eye. There is a small, specialized region in the central portion of the retina called the macula that is particularly important for central, sharp and color vision. It has a high percentage of photoreceptor cells called "cone cells" and it is this region that is most affected by AMD. Thus, with cone cell degeneration in AMD, a person loses their central, sharp vision with color vision affected as well.
  • In the normal retina, photoreceptor cells are supported metabolically and structurally by a thin layer of cells next to them called Retinal Pigment Epithelial (RPE)Cells. Without these RPE cells, photoreceptor cells quickly degenerate and die. In AMD, it is thought that dysfunction of RPE cells is an early and critical sign of AMD. Thus, replacing dead or dying RPE cells in AMD could be a way to slow the disease process and even improve vision.
  • Our CIRM disease team grant which we call The California Project to Cure Blindness aims to treat AMD through replacement of these dysfunctional RPE cells with fresh RPE cells that will then keep photoreceptor cells alive and functioning. Because only very few RPE cells are present in a human eye, direct RPE transplantation would be very difficult so we rely on the use of human embryonic stem cells (hESCs). Through the work in our CIRM funded disease team grant we have been able to use a particular stem cell line and differentiate into adult-like RPE cells that exhibit many characteristics of normal mature human RPE cells. We believe that implanting these hESCs within the eye next to the retina could be of benefit in AMD in saving the photoreceptors.
  • Our technique is to not only implant the hESC derived RPE cells in the eye but to place them on a special ultrathin substrate platform that will maintain them in proper orientation next to the retina. Moreover, implantation can be done with hESC cells that had been allowed to differentiate in tissue culture prior to implantation, insuring that the implanted cells indeed express the characteristics of mature, functional RPE cells.
  • In this last year, substantial progress has been made in progressing to our goal of replenishing RPE cells in the AMD retina and restoring vision. First, a specific hESC line has been identified that will differentiate into cells that have many of the morphological and biochemical characteristics of normal adult RPE cells. Second, an appropriate material has been found that can act as a substratum (platform) that will support the RPE cells and allow them to function in a normal manner. Third, we have begun to demonstrated the safety of our procedure as well as its efficacy in slowing vision loss in a rodent model of retina degeneration. Fourth, we also have developed unique surgical techniques that will allow us to safely and effectively place the cells in the animal and ultimately human eyes.
  • In parallel to these basic studies, we are advancing our strategies that will let us treat human patients with AMD. Clinical protocols are being established that will be submitted to the US FDA to gain their approval in order to start phase 1 (early) Clinical Trial. In summary, our CIRM grant has allowed us to develop a procedure that should let us treat severe vision loss in AMD. Already, data at 6 months in animal studies has demonstrated the safety of the technique as well as the restoration of functional vision in a model system. Hopefully, this will lead us to a successful human clinical trial with sight restoration in currently untreatable cases of dry AMD.

Phase 1 Safety Assessment of CPCB-RPE1, hESC-derived RPE Cell Coated Parylene Membrane Implants, in Patients with Advanced Dry Age Related Macular Degeneration

Funding Type: 
Disease Team Therapy Development III
Grant Number: 
DR3-07438
ICOC Funds Committed: 
$18 922 665
Disease Focus: 
Vision Loss
Stem Cell Use: 
Embryonic Stem Cell
oldStatus: 
Closed
Public Abstract: 
It is estimated that by 2020, over 450,000 Californians will suffer from vision loss or blindness due to the age-related macular degeneration (AMD), the most common cause of retinal degeneration in the elderly. AMD is a progressive ocular disease of the part of the retina, called the macula, which enables people to read, visualize faces, and drive. The disease initially causes distortion in central vision, and eventually leads to legal blindness. A layer of cells at the back of the eye called the retinal pigment epithelium (RPE), provides support, protection, and nutrition to the light sensitive cells of the retina; the photoreceptors. The dysfunction and/or loss of these RPE cells is believed to play a critical role in the subsequent death of photoreceptors and resulting loss of vision in AMD. Hence, if RPE cells can be restored, it may be possible to prevent or delay progressive vision loss in patients with AMD. We are developing a therapy to replace RPE cells in patients with a form of AMD known as geographic atrophy. The RPE cells are delivered on a synthetic membrane, just as normal RPE cells in the eye are arranged as a thin layer of cells on a substrate known as the Bruch’s membrane. We have made excellent progress in the current grant period funded by CIRM and are on track to file to an investigational new drug application to the FDA to start the phase 1 human study. We have also shown that our approach of delivering the RPE as a sheet into diseased animal eyes has a much better chance of restoring retinal function than if these cells were injected as a suspension. In this current grant from CIRM, we are seeking to translate this preclinical work and to test this product in a Phase I clinical trial in patients with geographic atrophy.
Statement of Benefit to California: 
Age-related macular degeneration (AMD) is the leading cause of vision loss and blindness among the elderly. It is estimated that over 1.75 million individuals in the US suffer from advanced AMD, and that this number will grow to nearly 3 million by 2020. Based on the demographics of California and the incidence rates of AMD among various age groups, it is anticipated that more than 400,000 Californians will develop advanced forms of AMD over the next 15 years. Although VEGF inhibitors such as Lucentis and Eylea provide therapeutic options for the wet form of AMD, no approved therapies currently exist for the advanced form of dry AMD, geographic atrophy, which is estimated to affect more than 100,000 Californians today, with another 160,000 new cases in California expected in the next 15 years. Studies have shown that the devastating consequences of AMD include the progressive loss of independence and productivity, and increased risks of falls, fractures, and depression among patients, resulting in substantial quality of life and economic impacts to many Californians. One health economics analysis estimated the total GDP from dry AMD in the United States to be more than $24 billion annually. Given that California accounts for more than 12% of US GDP, this analysis can be extrapolated to estimate that total GDP loss due to dry AMD in California is likely nearly $3 billion annually. In the proposed project, phase I clinical testing of an implant composed of an ultrathin membrane coated with human embryonic stem cell-derived retinal pigment epithelial cells (RPE), one of the key cell types known to primarily degenerate or die in AMD, will begin in patients with advanced AMD. This project has been developed in California and clinical testing will begin in California. This project will benefit the state of California by providing treatment options for the hundreds of thousands of Californians with dry AMD, providing support for the further development of a therapy originally developed with California, and creating jobs in California by enabling the formation a new California-based start-up to further develop this product.

Retinal progenitor cells for treatment of retinitis pigmentosa

Funding Type: 
Disease Team Therapy Development - Research
Grant Number: 
DR2A-05739
ICOC Funds Committed: 
$17 306 668
Disease Focus: 
Vision Loss
Stem Cell Use: 
Adult Stem Cell
Cell Line Generation: 
Embryonic Stem Cell
oldStatus: 
Active
Public Abstract: 
The targeted disease is retinitis pigmentosa (RP), a severe form of blindness that often runs in families, but other times arises spontaneously from genetic errors. This disease is not overly common, yet represents an attainable near term target for stem cell therapy for a number of reasons: 1) RP destroys the light detecting cells of the retina in the back of the eye, yet generally leaves the rest of the visual system and body unharmed, so the clinical goal is circumscribed; 2) RP is prototypical of degenerations of the nervous system, so a cure for this less common disease would accelerate progress towards new therapies for a range of more familiar conditions; 3) scientific research has shown that degenerating rods and cones can be saved in animals by transplanting particular types of stem cells, thus the scientific feasibility of treating RP in this way has already been established in principle. The therapeutic approach to be championed here is to save the light sensing cells of the eye (rod and cone photoreceptors) in people going blind using a type of stem cell obtained from the immature retina, but not from early embryos. These particular stem cells from the retina, known as progenitor cells, are capable of saving photoreceptors from degeneration following transplantation to the eye. These same cells are also highly efficient at producing new rod photoreceptors and this provides another more sustained pathway by which they preserve the crucial cone photoreceptors. In addition, there is evidence that the stem cells themselves might become functional photoreceptors and thereby stabilize the retina by directly replacing the dying cells in the patient’s eye. Thus, transplanted stem cells could treat the targeted disease of RP in multiple ways simultaneously. Importantly, there are a host of reasons why clinical trials in the eye are easier and safer than most locations in the body. The eye is an important proving ground for stem cell-based therapies and provides a stepping stone to many otherwise incurable diseases of the brain and spinal cord. As part of the current project, our cell type of interest will be grow under conditions ensuring pharmaceutical standards are met. The resulting cells will be tested in animals for safety and to make certain that they are therapeutically potent. An application will be made to the FDA seeking approval for the use of these cells in early clinical trials. Following approval, a small number of patients with severe RP will be injected with cells in their worse-seeing eye and followed clinically for a specified period of time to determine the safety and effectiveness of the treatment.
Statement of Benefit to California: 
Benefits to the state of California and its citizens are both direct and indirect. The direct benefit is medical in that there is currently no cure or established treatment for the individuals and families that suffer from the dreadful hereditary blindness known as retinitis pigmentosa. In addition, there are many people in California and throughout the world that suffer from degenerative diseases of the retina, such as age-related macular degeneration (AMD), and the central nervous system that could benefit from further development and alternate applications of the type of stem cell therapy proposed in the current application. The rapid progress into the clinic that could be achieved via this proposal would help legitimize the use of stem cells for previously incurable diseases and should thereby accelerate the development of stem cell-based therapeutics for a wide range of other conditions. In so doing there would be an indirect benefit to California by making our state a focal point for stem cell breakthroughs. This would increase medical capabilities, strengthen the state’s educational system, and energize local biotechnology companies with outside investment and a payoff in jobs and tax revenues. In the current economic situation, the citizens of the state are looking for a return on their investment in stem cell research. The leadership for the state is looking for a novel technology to reinvigorate the economy, provide desirable jobs, and reaffirm the flagship image of California. The project presented in this application has a real chance of provide that sort of spark.
Progress Report: 
  • Retinitis pigmentosa (RP) is a severe form of blindness that often runs in families, but other times arises spontaneously or from recessive genetic errors. This disease is rare, yet represents an attainable near term target for stem cell therapy for a number of reasons: 1) RP destroys the light detecting cells of the retina in the back of the eye, yet generally leaves the rest of the visual system and body unharmed, so the clinical goal is circumscribed; 2) RP is prototypical of degenerations of the nervous system, so a cure for this less common disease would accelerate progress towards new therapies for a range of more familiar conditions; 3) scientific research has shown that degenerating rods and cones can be saved in animals by transplanting particular types of stem cells, thus the scientific feasibility of treating RP in this way has already been established in principle. The therapeutic approach pursued by our team is to save the light sensing cells of the eye (rod and cone photoreceptors) by transplanting a type of stem cell known as a progenitor cell. These cells are capable of saving photoreceptors from degeneration following transplantation to the eye. These same cells are also highly efficient at producing new rod photoreceptors and this provides another more sustained pathway by which they preserve the crucial cone photoreceptors. In addition, there is evidence that the stem cells themselves might become functional photoreceptors and thereby stabilize the retina by directly replacing the dying cells in the patient’s eye. Thus, transplanted stem cells could treat the targeted disease of RP in multiple ways simultaneously. Importantly, there are a host of reasons why clinical trials in the eye are easier and safer than most locations in the body. The eye is therefore an important proving ground for stem cell-based therapies and provides a steppingstone to many otherwise incurable diseases of the brain and spinal cord.
  • As part of the current project, our cell type of interest has now been manufactured under specific conditions ensuring that pharmaceutical standards are met (Good Manufacturing Practice, GMP). The resulting GMP cells have been tested in the laboratory to verify that they are free from microbial contamination and chromosomal defects. The cells are currently being tested in animals for safety and to make certain that they are therapeutically potent. When this testing is completed, an application will be made to the FDA seeking approval for the use of these cells in early clinical trials. Following approval, a small number of patients with severe RP will be injected with cells in their worse-seeing eye and followed clinically for a specified period of time to determine the safety and effectiveness of the treatment.

Pages

Subscribe to RSS - Vision Loss

© 2013 California Institute for Regenerative Medicine