Cell Therapy for Diabetes: Expansion and re-differentiation of adult human pancreatic islet cells for transplantation (Ramot)
Prof. Efrat has developed a protocol for re-differentiating human beta cells after expansion; this can be explained by the open chromatin structure around beta-cell-specific genes that is retained in these cells. Thus, the cells can be expanded and then redifferentiated to beta cells to provide an expanded number of functional insulin producing cells. The entire process is performed in xeno-free defined media.Stage of Development
Beta-cell labeling with a fluorescent protein demonstrates replication of cells derived from islet beta cells. 40% of replicating cells are derived from beta cells. Fluorescent cells can be sorted and expanded in pure cultures.
Replication is accompanied by a decrease in expression of key beta-cell genes
Cell dedifferentiation and proliferation in vitro correlate with reactivation of the NOTCH pathway. Inhibition of HES1 expression using shRNA during culture initiation results in reduced β-cell replication and dedifferentiation, suggesting that HES1 inhibition may also affect cell redifferentiation following expansion.
Shift to differentiation conditions following expansion results in restoration of beta-cell gene expression and insulin production.
In vivo analyses demonstrated the ability of the redifferentiated cells to replace β-cell function in hyperglycemic immunodeficient mice.
· Adult tissue source
· Growth in defined media
· No gene modification
· Expansion of over 65,000 fold (within 4 months)
Expansion of functional islet cells from single cadaveric donors for transplantation into multiple recipients for the treatment of diabetes and as a valuable tool for drug screening (organ-in-a tube).
10-2007-107
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