Counter to the prevailing theory that beta cells die-off in Type 2 diabetes patients, NYSCF – Druckenmiller Fellow and postdoctoral research scientist at Columbia University Medical Center Chutima Talchai, PhD, is co-author on a paper in Cell that suggests these insulin-producing cells de-differentiate. Employing cellular lineage tracking, Dr. Talchai and her colleagues followed beta cells in Type 2 diabetic mice models. They discovered that these cells reverted to an immature state, rendered unable to produce insulin. These results could inform how diabetes is treated by identifying an agent to help re-differentiate these affected cells.
Dieter Egli, PhD, a NYSCF Senior Research Fellow, is co-author on a paper published in the August 19th edition of Nature Genetics, a study conducted in collaboration with the research group of Alex Meissner, PhD, of Harvard University. They studied how the mouse egg erases methylation marks on DNA that are specific to specialized adult cells yet differ in comparison to embryonic stem cells. These methylation marks are thought to be a major barrier in the reprogramming of a specialized cell to a stem cell. Within twelve days after nuclear transfer, they found that regulatory regions of genes were demethylated while repetitive DNA sequences remained methylated. This finding suggests that the egg contains factors that mediate the rapid and specific demethylation of genes, which may be important for development. Thereby, this work elucidates the potential of oocytes to reprogram specialized cells into stem cells.
At the Alzheimer’s Association International Conference this past July, Andrew Sproul, PhD, a NYSCF Postdoctoral Associate, presented NYSCF’s latest efforts to understand Alzheimer’s disease. They have generated relevant induced pluripotent stem (iPS) cell models from AD patients and well relatives that were then differentiated into cholinergic neurons. Other efforts in the generation of human iPS cell disease models include cortical neurons from Down’s syndrome patients and the creation of cell lines from ALS patients. These iPS lines reveal the underlying biology that animal models do not.
Dieter Egli, a NYSCF Senior Research Fellow, contributed to a study published in Molecular Medicine that provides direct evidence of sight-loss recovery using induced pluripotent stem (iPS) cell transplantation. In collaboration with Stephen Tsang, PhD, from Columbia University, Egli provided human retinal pigmented epithelium cells, derived from iPS cells. These cells were then grafted into mice genetically engineered to suffer from retinitis pigmentosa, a degenerative eye disease that causes vision impairment and blindness. Tests to measure visual function revealed improved sight in these mice. This autologous iPS cell graft could lead to clinical applications in human patients diagnosed with macular or retinal degeneration.
Dung-Fang Lee, PhD, a NYSCF – Druckenmiller Fellow Alumnus at Mount Sinai School of Medicine, has published a new study in the August edition of Cell Stem Cell that elucidates a molecular signal necessary to maintain self-renewal and pluripotency in embryonic stem cells (ESCs) and somatic cells. When regulatory molecule aurora kinase A was depleted, Dr. Lee and his team found inhibited gene expression in ESCs. This suggests the essential role aurora kinase A signaling plays in cell differentiation, self-renewal, and reprogramming.
