Evaluation of therapeutic efficiency of in vivo transfection of rat intestinal crypt CBC stem cells using orally delivered GIP/Ins-PiggyBac gene construct expressing insulin in differentiated K cells for type 1 diabetes mellitus
Principle investigator: Rasol Salehi
Type 1 diabetes mellitus (T1DM), a chronic metabolic disorder, caused by autoimmune destruction of pancreatic β-cells. The most common current treatment for T1DM is exogenous insulin administration; however, ideal blood glucose level is rarely achieved, hence incidence of debilitating complications of diabetes would be very often.
Novel therapeutic options like gene therapy created much hope to provide accurate and prolonged relief. To be approved as an ideal therapeutic modality, gene therapy must fulfill several criteria including safe delivery vectors, delivery route and suitable candidate cells for ectopic and regulated insulin production according to the patient body requirements.
Intestinal K-cells are suitable ectopic cells for regulated insulin secretion. It has been previously demonstrated that production of insulin in intestinal K cells under glucose‐dependent insulinotropic peptide (GIP) promoter, protected mice against streptozotocin (STZ)-induced diabetes. GIP is an incretin hormone secreted from enteroendocrine K‐cells upon sensing glucose and some other nutrients. The main drawback of intestinal k-cells to be used as ectopic insulin production is their short half-life of around 3-5 days which is a serious limitation for stable and prolonged insulin production. Safe, efficient and integrative vector is needed for delivery of insulin gene. Transposon based vectors (PiggyBac) are proved to provide higher level of safety comparing to the commonly used lentivirus vectors. Also for targeted delivery of insulin gene construct, oral rout would be the most convenient. However the main barrier for oral delivery is the harsh and complex environment of the stomach with various destructive enzymes. Hence intensive protection measures should be consider for safe travelling of the gene construct along the GI tract.
In the current project we are going to examine the feasibility of our hypothesis and finding applicable solutions to overcome the limitations exist in using intestinal k-cells as an ideal cell source for ectopic and regulated insulin production.