Cyclin Dependent Kinase 5 (CDK5): the possible connection in insulin‐related neurodegenerative diseases

Cyclin Dependent Kinase 5 (CDK5) is a member of the cyclin‐dependent kinase family, regulators of the cell cycle. Although CDK5 has > 65% homology with this family, it has no known role in cell cycle regulation and is activated by a‐typical cyclin activating partners. CDK5 is suggested to have a role in establishing the neuronal phenotype and many of its substrates affect cell morphology and motility. Through studies of chemical inhibition of CDK5 during the neurotrophic‐induced differentiation of a neuronal cell model, our lab has shown CDK5's importance in establishment of the neuronal phenotype. These results are in good agreement with published reports. CDK5 is recently reported to play a role in non‐neuronal tissue such as the pancreas, where it may function in the insulin‐positive phenotype. Using a pancreatic cell model AR42J, we studied CDK5's role during the transdifferentiation of these acinar cells into insulin‐positive cells. Here we show results of those studies including confirmation of transdifferentiation through mRNA analysis and the impact of chemical inhibition of CDK5. To explore the connection between the developing pancreas and the nervous system, we additionally employed a novel co‐cultivation method of our two cell models. From these investigations we begin to examine the reported correlation between insulin‐related illness and the likelihood of developing neurodegenerative diseases.