Response of Chick B Islets to Insulin Secretagogues is Comparable to those of Human Islet Equivalents

Context The B islets isolated from 3-5 day old chick respond well to glucose challenge in a similar fashion to those isolated from mouse pancreas. Objective To compare insulin secretory response of chick B islets with that of human Islet Equivalents (hIEqs) generated from stem cells. Methods Human Umbilical Cord Mesenchymal Stem Cells (UC-MSCs) were differentiated into hIEqs employing three step sequential serum free protocols. Results Immunofluorescence staining demonstrated Insulin, C peptide and Glut 2 positivity of both these islets. Static insulin stimulation of these islets in response to glucose, metformin and Gama Amino Butyric Acid (GABA) resulted in increased insulin secretion as compared to basal glucose stimulation. Our results demonstrate that insulin secretory response of Chick B islets to Metformin and GABA is comparable to those of hIEqs. Moreover, both chick and hIEqs could be successfully cryopreserved and revived in a commercially available cryomix Cryostore 5, indicating resemblance in their behaviour at sub-zero temperatures. Conclusion Present study advocates Chick islets as an alternative source for diabetes research and islet banking. Received December 07th, 2014 – Accepted March 25th, 2015