Human Embryonic Stem Cells and Neural Crest Plasticity

Funding Type: 
SEED Grant
Grant Number: 
RS1-00333
ICOC Funds Committed: 
$0
Disease Focus: 
Amyotrophic Lateral Sclerosis
Neurological Disorders
Spinal Cord Injury
Neurological Disorders
Stem Cell Use: 
Embryonic Stem Cell
Public Abstract: 
Craniofacial anomalies and bone defects pose a difficult and challenging problem both for the doctor and for patients along with their families. A great demand exists for the repair of craniofacial bone defects. Orofacial defects repaired with grafts obtained from an orofacial donor site are usually more successful than those from non-orofacial sites. However, the efficacy is limited by high cost, donor morbidity, and scarcity of orofacial tissue sources. Some skeletal diseases such as cherubism, hyperparathyroid jaw tumor syndrome and craniofacial fibrous dysplasia affect only orofacial bones. Studies of the craniofacial skeleton also indicate that molecular mechanisms controlling skeletogenesis in the head are unique and distinctive from those occurring in other body sites. Neural crest cells are multipotent stem cells that contribute to a diverse array of tissues throughout the embryo. During craniofacial development, cranial neural crest contributes extensively to the formation of mesenchymal structures in the head and neck, such as orofacial bone, cartilage, tooth and cranial nerve ganglia. The majority of orofacial skeleton is neural crest derived. In this application, we propose to derive cranial neural crest-like progenitor cells from human embryonic stem cells and subsequently induce bone formation by these cranial neural crest-like cells. Bone tissues generated from cranial neural crest-like cells share similar developmental origin with craniofacial bones, thereby representing a superior therapeutic tissue source for craniofacial bone repair. The results from this proposal will be used to optimize strategies for maintenance of stem cell populations while improving our ability to stimulate the development of cell specific lineages needed for the repair and regeneration of defects in craniofacial tissues.
Statement of Benefit to California: 
Craniofacial anomalies and bone defects pose a difficult and challenging problem both for the doctor and for patients along with their families. A great demand exists for the repair of craniofacial bone defects. Orofacial defects repaired with grafts obtained from an orofacial donor site are usually more successful than those from non-orofacial sites. However, the efficacy is limited by high cost, donor morbidity, and scarcity of orofacial tissue sources. This proposal will benefit the people and the state of California by deriving cranial neural crest-like progenitor cells from human embryonic stem cells. Bone tissues generated from cranial neural crest-like cells share similar developmental origin with craniofacial bones, thereby representing a superior therapeutic tissue source for craniofacial bone repair.
Progress Report: 
  • A main goal of research in our laboratory is to identify strategies to promote neural repair in spinal cord injury and related neurological conditions. On the one hand, we have been using mouse models of spinal cord injury to study a long-standing puzzle in the field, namely, why axons, the fibers that connect nerve cells, do not regenerate after injury to the brain and the spinal cord. On the other hand, relevant to this CIRM SEED grant, we have started to explore the developmental and therapeutic potential of human embryonic stem cells (hESCs) for neural repair. We do this by first developing a method to genetically manipulate a HUES line of hESCs. The advent of hESCs has offered enormous potential for regenerative medicine and for basic understanding of human biology. To attain the full potential of hESCs as a tool both for therapeutic development and for basic research, we need to greatly enhance and expand our ability to genetically manipulate hESCs. A major goal for our SEED grant-sponsored research is to establish methods to genetically manipulate the HUES series of hESC lines, which are gaining wide utility in the research community due to the advantages on their growth characteristics over previously developed hESC lines. The first gene that we targeted in HUES cells, Fezf2, is critical for the development of the corticospinal tract, which plays important roles in fine motor control in humans and hence represents an important target for recovery and repair after spinal cord injury. By introducing a fluorescent reporter to the Fezf2 locus, we are now able to monitor the differentiation of hESCs into Fezf2-expressing neuronal lineages. This work has been published. A second goal is to start to explore the developmental and therapeutic potential of these cells and cells that derived from these cells in the brain and spinal cord. We are currently utilizing the cell line genetically engineered above to develop an efficient method to differentiate HUES cells into subcerebral neurons. Results so far have been encouraging. Efforts are also underway to overexpress Fezf2 as a complementary approach to drive the differentiation of HUES cells into specific neuronal types. Together, these studies will lay down the foundation for therapeutic development with HUES cells and their more differentiated derivatives for neurological disorders including spinal cord injury where neural regeneration can be beneficial. The CIRM SEED grant has allowed us to pursue a new, exciting path of research that we would have not pursued had we not been awarded the grant. Furthermore, the CIRM funded research has opened a new window of opportunity for us to explore genetic engineering of hESCs to model human neurological conditions in future.

© 2013 California Institute for Regenerative Medicine