Liver Disease

Coding Dimension ID: 
301
Coding Dimension path name: 
Liver Disease
Funding Type: 
Early Translational II
Grant Number: 
TR2-01857
Investigator: 
Name: 
Type: 
PI
ICOC Funds Committed: 
$5 199 767
Disease Focus: 
Liver Disease
Stem Cell Use: 
Embryonic Stem Cell
oldStatus: 
Active
Public Abstract: 

Because there is still considerable morbidity and mortality associated with the process of whole liver transplantation, and because more than a thousand people die each year while on the liver transplantation list, and tens of thousands more never get on the list because of the lack of available livers, it is evident that improved and safer liver transplantation would be valuable, as would approaches that provide for an increased number of transplantations in a timely manner. A technology that might address these issues is the development of a human liver cell line that can be employed in liver cell transplantation or in a bioartificial liver. Developing such a cell line from human embryonic stem cells (hESC) would provide a valuable tool for pharmacology studies, as well as for use in cell-based therapeutics. The objective of this proposal is to focus a team effort to determine which differentiated hESC will be the most effective liver-like cells in cell culture and in animal studies, and to then use the best cells in clinical trials of cell transplantation in patients with advanced liver disease.

In the proposed studies, the team will differentiate hESC so that they act like liver cells in culture. Once it has been established that the cells are acting like liver cells by producing normal human liver proteins, and that they do not result in tumors, the cells will be assessed in clinically-relevant models using techniques that can then be adapted to future human clinical trials. One of the ways cells can be evaluated is to label the cells which will provide a means to monitor them with various imaging systems. The intent in these studies is to determine which will be the most effective cells to use in human clinical trials. Once this is determined, the best cells can then be employed in human patients.

If the studies are successfully undertaken, we will have established a clinically useful and viable liver cell line that could be used to repopulate an injured liver in a safer and less expensive manner than with whole liver transplantation. Moreover, all people who have liver failure or an inherited liver disease could be treated, because there would be an unlimited supply of liver cells.

Statement of Benefit to California: 

In California, as in all parts of the US, there are not enough livers available for transplantation for all the people who need them. The result is that many more people die of liver failure than is necessary. One way to improve this situation is the transplantation of liver cells rather than whole organ transplantation. We are attempting to develop liver cell lines from stem cells that will act like normal liver cells. If the cells that we develop function well and do not act like cancer cells in culture, the cells will be assessed in clinically-relevant models using techniques that can then be adapted to future human clinical trials. In our studies, we will compare human embryonic stem cells with other stem cells to determine which will be the most effective cells to transplant into people. In the future, we will employ the best cells in clinical trials in humans. If the studies are successfully undertaken, we will have established a clinically useful and viable liver cell line that could be used to repopulate an injured liver in a safer and less expensive manner than with whole liver transplantation. Moreover, all people who have liver failure or an inherited liver disease could be treated, because there would be an unlimited supply of liver cells.

Progress Report: 
  • Because there is still considerable morbidity and mortality associated with the process of whole liver transplantation, and because more than a thousand people die each year while on the liver transplantation list, and tens of thousands more never get on the list because of the lack of available livers, it is evident that improved and safer liver transplantation would be valuable, as would approaches that provide for an increased number of transplantations in a timely manner. A technology that might address these issues is the development of a human liver cell line that can be employed in liver cell transplantation or in a bioartificial liver. Developing such a cell line from human embryonic stem cells (hESC) would provide a valuable tool for pharmacology studies, as well as for use in cell-based therapeutics. The objective of this proposal is to focus a team effort to determine which differentiated hESC will be the most effective liver-like cells in cell culture and in animal studies, and to then use the best cells in clinical trials of cell transplantation in patients with advanced liver disease.
  • In the past year, we have been able to differentiate hESC so that they act like liver cells in culture. The cells are acting like liver cells by producing normal human liver proteins, and they metabolize drugs in a manner similar to liver cells, and they do not cause tumors when transplanted. Now we are ready to assess the cells in clinically-relevant models using techniques that can then be adapted to future human clinical trials. The intent in these studies is to determine which will be the most effective cells to use in human clinical trials. Once this is determined, the best cells can then be employed in human patients.
  • If the studies are successfully undertaken, we will have established a clinically useful and viable liver cell line that could be used to repopulate an injured liver in a safer and less expensive manner than with whole liver transplantation. Moreover, all people who have liver failure or an inherited liver disease could be treated, because there would be an unlimited supply of liver cells.
  • Some patients with life-threatening liver disease can be effectively treated with liver transplantation. However, this requires a major surgical procedure that is associated with considerable morbidity and mortality. More importantly, the long-standing shortage of donor livers has rendered this treatment unavailable to most patients. Consequently, thousands of patients with end-stage liver disease die each year while on a waiting list for liver transplantation, and tens of thousands are never put on this list. Since human embryonic stem cells replicate virtually indefinitely in culture, these cells, if differentiated into liver cells (hepatocytes), represent an infinite source of cells that can be made available to treat patients with liver failure.
  • The objective of this award than is to develop a reproducible and efficient differentiation method to produce metabolically active human embryonic stem cell-derived hepatocytes. The initial requirement is that at least 90-95% of the cells must have liver-specific gene expression and possess metabolic function comparable to freshly isolated human hepatocytes. In addition, the yield from differentiation should be adequate to support preclinical studies. We believe that we made excellent progress during the grant award period towards meeting the success criteria for the quality of the cells in in vitro analysis. We firmly believe that our cells represent an exceedingly good level of hepatocyte function in culture, and that the remaining tasks are to scale-up their production and to determine a strategy to enhance their in vivo function.
  • The objective of this Early Translational II Research Award is to develop a reproducible and efficient differentiation method to produce metabolically active human embryonic stem cell-derived hepatocytes (hEDH)(also called liver cells). We have determined that at least 90-95% of the cells have liver-specific gene expression and possess biotransformation ability comparable to freshly isolated human hepatocytes. This means that our cells that we have differentiated from embryonic stem cells are acting like human liver cells. In addition, the yield from differentiation should be adequate to support preclinical studies. We believe that we made excellent progress during the grant award period towards meeting the success criteria for the quality of the cells and that further work may well yield cells that can be transplanted into people.
Funding Type: 
Tools and Technologies I
Grant Number: 
RT1-01012
Investigator: 
Type: 
PI
ICOC Funds Committed: 
$971 558
Disease Focus: 
Liver Disease
Toxicity
Stem Cell Use: 
Embryonic Stem Cell
oldStatus: 
Closed
Public Abstract: 

Drug-induced liver toxicity, including that from FDA-approved drugs, is the leading cause of liver failure in the US. One of the biggest road blocks to testing drug-induced liver toxicity prior to clinical studies or release of the drug into the market is the absence of a good model of human drug metabolism in the liver. Development of a clinically predictive drug screening system would allow earlier detection of drug-induced liver toxicity, thus decreasing drug costs, decreasing the scale of pre-clinical animal testing, and increasing drug safety. Unfortunately, use of primary human liver cells for drug screening is hampered by their limited availability and poor viability in culture. Human embryonic stem (hES) cells, however, could provide a renewable, scalable, relevant source of liver cells since they can be induced to turn into these types of cells. Unfortunately, though, current hES protocols yield primarily immature liver cells, even though mature adult-like liver cells would be needed for drug screening. Here we propose development of a new hES cell line tool that attaches a fluorescent molecule to a protein found in mature liver cells. This would be a very powerful tool for two key avenues of study and development. First, it will facilitate testing of new methods to enhance the maturation of hES-derived liver cells, ultimately leading to better protocols for transplantation and regenerative medicine purposes. Second, it will also be instrumental in screening for drug-induced liver toxicity effects. While [REDACTED] interests lie more with the usage of this tool for drug screening purposes, we plan to openly share this tool with the scientific community under standard licensing agreements so that rapid progress can be made in both these areas.

Statement of Benefit to California: 

This proposal has been submitted by a California company whose mission is to develop and commercialize ES cell-based assays to aid in drug discovery and development. Using stem cells to model how the liver metabolizes drugs would lead to earlier detection of drug-induced liver toxicity, keeping many of the more dangerous clinical drugs from ever reaching the market. This would increase drug safety, decrease drug costs, and decrease the scale of pre-clinical animal testing that is currently used in drug development benefiting all Californians.

The work outlined in this proposal will also bring significant revenue into California, in various different forms. Whenever possible, we will continue to order supplies and/or use services through our standing relationships with California vendors, such as E&K Scientific (Santa Clara, CA), Invitrogen (Carlsbad, CA), and Stanford University Core Research facilities in order to support California businesses and universities. Partnering and licensing of the technology developed in this proposal, as well as commercialization of new and safer drugs, would bring revenue and additional jobs into California. In addition, patents arising from these technologies are also potentially significant for California, due to the licensing revenue fees that would go back to the state.

The ES cell line tool generated as a result of this proposal, along with the reagents used to make it, will be shared openly with the scientific community under transfer and/or licensing agreements that are standard to both academic and industrial scientific entities. This will facilitate rapid progress toward two key avenues of research and development: 1) screening drugs for potential toxic effects on the liver and 2) for better understanding liver development, ultimately leading to better protocols for transplanting ES-derived liver cells into patients with liver disease or drug-induced liver toxicity. This would also result in more jobs in California to carry out this work and would form the basis of additional academic and corporate collaborations that would increase California's leadership role in stem cell applications.

Progress Report: 
  • The leading cause of liver failure in the US is drug-induced liver toxicity. Currently there is an absence of a good model of human drug metabolism in the liver, which poses one of the biggest road blocks to testing drug-induced liver toxicity prior to clinical studies or release of the drug into the market. We are using human embryonic stem (hES) cells to develop a clinically predictive drug screening system that should allow earlier detection of drug-induced liver toxicity, thus decreasing drug costs, decreasing the scale of pre-clinical animal testing, and increasing drug safety. There are two arms to this work. The first is to engineer a new hES cell line that attaches a fluorescent molecule to a protein found in mature liver cells. To date we have completed the genetic molecules necessary for development of this cell line, and we are currently using these molecules to generate the engineered hES cell line. The second arm is to test new methods to enhance the maturation of hES-derived liver cells, since current hES protocols only yield immature liver cells. As part of this approach, we are testing a novel 3D culture system that has already been shown to improve maturation of other cell types, such as heart cells and fresh liver cells from humans. By combining our new hES cell line with improved protocols for generating mature hES-derived liver cells, we will have a powerful system not only for screening drugs for potential liver toxicity effects but also for improving protocols for transplantation and regenerative medicine purposes. We plan to openly share this new cell line with the scientific community under standard licensing agreements so that rapid progress can be made in both these areas.
  • We have developed and validated two human ES cell clones that have the BLA reporter correctly targeted into the CYP3A4 gene. In addition, we have made major improvements to the hepatocyte differentiation protocols, resulting in cultures with greater than 85% hepatocytes, which express significant levels of mature hepatocyte proteins and drug metabolizing enzymes, including albumin, CYP1A2 and CYP3A4. Furthermore, these cultures demonstrate CYP1A2-dependent metabolism of acetaminophen, which is approximately 20% of the activity, on a per cell basis, seen from primary human hepatocytes. This is significantly more than we have seen with any other protocols. We expect to use these cells in our drug development programs as screening assays for liver metabolism and toxicity studies.
  • We have successfully achieved the major aim of this grant, which was to develop a new human embryonic stem (hES) cell line in which a fluorescent molecule is attached to a protein found in mature liver cells. This protein is responsible for metabolizing the majority of drugs currently in the market, so it is critical to understand the effect that different drugs have on the function of this protein so that drug-induced liver toxicity, which is the leading cause of liver failure in the US, can be reduced. We have done extensive validation of this cell line tool, and we are currently in the process of developing it into an assay system for screening compounds for drug-induced liver toxicity effects. There is a great need for this type of assay since there is currently an absence of a robust model of human drug metabolism in the liver. As part of this development, we have also done extensive work optimizing the generation of liver cells from hES cells. We now can differentiate hES cells into nearly pure populations of cells that are precursors to liver cells and we are currently using our new cell line to facilitate testing new methods to enhance the maturation of these precursors into hES-derived liver cells. The combination of using our new cell line tool in an optimized protocol for generating hES-derived liver cells will hopefully result in a clinically predictive drug screening system that will allow earlier detection of drug-induced liver toxicity, decreased pre-clinical animal testing, and increased drug safety. We are committed to aggressively continuing this work even beyond the close of this grant funding to achieve the goal of a human cell-based, clinically predictive liver toxicity drug screening system.
Funding Type: 
Comprehensive Grant
Grant Number: 
RC1-00359
Investigator: 
Name: 
Type: 
PI
ICOC Funds Committed: 
$2 504 614
Disease Focus: 
Liver Disease
Stem Cell Use: 
Adult Stem Cell
Embryonic Stem Cell
oldStatus: 
Closed
Public Abstract: 

Because there is still considerable morbidity and mortality associated with the process of transplantation, and because more than a thousand people die each year while on the liver transplantation list, it is evident that improved and safer liver transplantation would be valuable, as would approaches that provide for an increased number of transplantations in a timely manner. A technology that might address these issues is the development of a human liver cell line that can be employed in liver cell transplantation or in a bioartificial assist device. Developing such a cell line from human embryonic stem cells (hESC) or from other human stem cell sources would provide a valuable tool for pharmacology studies, as well as for use in cell-based therapeutics.

In the proposed studies, we will differentiate human embryonic stem cells or fetal liver cells or bone-marrow derived cells so that they act like liver cells in culture. Once it has been established that the cells are acting like liver cells by producing normal human liver proteins, and that they do not act like cancer cells, the cells will be injected into the livers of immunoincompetent mice that do not rejects human cells. Then we will evaluate whether the cells grow and thrive in the mouse livers, whether they still produce high levels of human liver-specific proteins, whether they produce tumors in the mouse livers, and whether they can replace damaged mouse liver cells with human cells. One of the ways this will be done is to label the cells with a marker gene and to image the marker gene in the livers of the mice with special x-ray machines that can distinguish a few hundred human cells in the mouse liver. Finally, we will infuse the human liver stem cells into the liver of monkeys to determine if they will grow in the monkey livers, because the monkeys are more similar to man. Such studies should be done in nonhuman primates before clinical studies are undertaken to employ these cells to replace abnormal liver cells in man. Our intent is these studies is to compare and contrast three types of stem cells to determine which will be the most effective cells to use in human studies.

If the studies are successfully undertaken, we will establish a clinically useful and safe liver cell line that could be used to repopulate an injured liver in a safer and less expensive manner than with liver transplantation; moreover, all people who had liver failure or an inherited liver disease could be treated, because there would be an unlimited supply of liver cells.

Statement of Benefit to California: 

In California, as in all parts of the US, there are not enough livers available for transplantation for all the people who need them. The result is that many more people die of liver failure than is necessary. One way to improve this situation is the transplantation of liver cells rather than whole organ transplantation. We are attempting to develop liver cell lines from stem cells that will act like normal liver cells. If the cells that we develop function well and do not act like cancer cells in culture, we will then transplant them into special mouse models of liver disease and see if the human cells can rescue the mouse from its liver disease. As a final test, we will see if the cells function in primate livers. In our studies, we will compare human embryonic stem cells with adult stem cells to determine which will be the most effective cells to transplant into people. If the studies are successfully undertaken, it means that we will have a stem cell line that can then be employed in human studies to determine their safety and effectiveness.

Progress Report: 
  • Because there is still considerable morbidity and mortality associated with the process of whole liver transplantation, and because more than a thousand people die each year while on the liver transplantation list, and tens of thousands more never get on the list because of the lack of available livers, it is evident that improved and safer liver transplantation would be valuable, as would approaches that provide for an increased number of transplantations in a timely manner. A technology that might address these issues is the development of a human liver cell line that can be employed in liver cell transplantation or in a bioartificial liver. Developing such a cell line from human embryonic stem cells (hESC) or from other human stem cell sources would provide a valuable tool for cell-based therapeutics.
  • In the past year, we have improved on our ability to differentiate the hESC towards liver cells in culture. They are producing normal human liver proteins. They also are capable of metabolizing drugs and other substances in the same manner of normal liver cells in culture. This means that they have the most important attributes of normal liver cells. Also, we have employed these cells in clinically-relevant models using techniques that can then be adapted to future human clinical trials. Moreover, they do not produce tumors.
  • In addition, we are employing adult stem cells derived from the bone marrow in collaborative studies with colleagues in Egypt. These stem cells have been differentiated so that they act like liver cells, and they have been transplanted into patients with advanced liver disease. The patients that have received the cells have improvement in their blood tests, and they are living longer than would have been expected without the transplantation.
  • Thus we are making some progress in establishing a clinically useful and viable liver cell line that could be used to repopulate an injured liver in a safer and less expensive manner than with liver transplantation.
  • Because there is still considerable morbidity and mortality associated with the process of whole liver transplantation, and because more than a thousand people die each year while on the liver transplantation list, and tens of thousands more never get on the list because of the lack of available livers, it is evident that improved and safer liver transplantation would be valuable, as would approaches that provide for an increased number of transplantations in a timely manner. A technology that might address these issues is the development of a human liver cell line that can be employed in liver cell transplantation or in a bioartificial liver. Developing such a cell line from human embryonic stem cells (hESC) or from other human stem cell sources would provide a valuable tool for cell-based therapeutics.
  • In the past year, we have improved on our ability to differentiate the hESC towards liver cells in culture. They are producing normal human liver proteins. They also are capable of metabolizing drugs and other substances in the same manner of normal liver cells in culture. This means that they have the most important attributes of normal liver cells. Also, we have employed these cells in clinically-relevant models using techniques that can then be adapted to future human clinical trials. Moreover, they do not produce tumors.
  • We have also worked to differentiate human induced pluripotent cells (hiPSC) to become liver-like cells in culture. The hiPSC behave very much like hESC, in that they are pluripotent. However, they are derived from adult somatic cells and thus do not have the ethical concerns associated with hESC. Our differentiation protocol has been successful in deriving cells that again have most of the important attributes of normal liver cells. Thus, we are hopeful that they also may be helpful for cell-based therapeutics in the future.
  • In addition, we are employing adult stem cells derived from the bone marrow in collaborative studies with colleagues in Egypt. These stem cells have been differentiated so that they act like liver cells, and they have been transplanted into patients with advanced liver disease. The patients that have received the cells have improvement in their blood tests, and they are living longer than would have been expected without the transplantation.
  • Thus we are making some progress in establishing a clinically useful and viable liver cell line that could be used to repopulate an injured liver in a safer and less expensive manner than with liver transplantation.
  • Because there is still considerable morbidity and mortality associated with the process of whole liver transplantation, and because more than a thousand people die each year while on the liver transplantation list, and tens of thousands more never get on the list because of the lack of available livers, it is evident that improved and safer liver transplantation would be valuable, as would approaches that provide for an increased number of transplantations in a timely manner. A technology that might address these issues is the development of a human liver cell line that can be employed in liver cell transplantation or in a bioartificial liver. Developing such a cell line from human embryonic stem cells (hESC) or from other human stem cell sources would provide a valuable tool for cell-based therapeutics.
  • In the past year, we have improved on our ability to differentiate the hESC towards liver cells in culture. They are producing normal human liver proteins. They also are capable of metabolizing drugs and other substances in the same manner of normal liver cells in culture. This means that they have the most important attributes of normal liver cells. Also, we have employed these cells in clinically-relevant models using techniques that can then be adapted to future human clinical trials. Moreover, they do not produce tumors.
  • We have also worked to differentiate human induced pluripotent cells (hiPSC) to become liver-like cells in culture. The hiPSC behave very much like hESC, in that they are pluripotent. However, they are derived from adult somatic cells and thus do not have the ethical concerns associated with hESC. Our differentiation protocol has been successful in deriving cells that again have most of the important attributes of normal liver cells. Thus, we are hopeful that they also may be helpful for cell-based therapeutics in the future.
  • Thus we are making some progress in establishing a clinically useful and viable liver cell line that could be used to repopulate an injured liver in a safer and less expensive manner than with liver transplantation.

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