Type 2 diabetes mellitus (T2DM) has been shown to be associated with hyperglycemia, insulin resistance, hyperinsulinemia and impaired insulin secretion from pancreatic β-cells leading to micro- and macro-vascular complications including multiorgan failures. At the cellular level, the mechanism of insulin resistance is associated with complex PI3K-Akt mediated insulin signaling pathway. Moreover, lipid phosphatase SHIP2 (Src homology 2 domain containing inositol 5-phosphatase 2) plays a vital role as a negative regulator of the insulin signaling pathway downstream of PI3K by hydrolyzing phosphatidylinositol- 3,4,5-trisphosphate (PIP3) into phosphatidylinositol- 3,4- biphosphate (PIP2). Scientific reports have shown that inhibition of SHIP2 activity might improve Akt phosphorylation and thus PI3K-Akt mediated insulin signaling pathway. Considering this, I am interested in the SHIP2 inhibitors with drug like properties such as improved solubility, pharmacokinetic and bioavailability properties with little to no contraindications.
In the present thesis, I have attempted to detect indirectly the capacity of 8 novel small molecule SHIP2 inhibitors, #160, #161, #162, #163, #167B, #170A, #171, #172 for their ability to phosphorylate Akt kinase in L6 myotubes using immunoblotting as a tool and compared data using graphical representation to pick up the best candidate. Two inhibitors, #163 and #170A were further chosen for alamarBlue® cytotoxicity assay. Treatment with #163 did not display direct cytotoxic effects on the myotubes. The viability of myotubes was not affected at low concentrations of #170A, but it started to reduce at concentrations >200 µM. In my study, I came up with #163 and #170A as the best lead candidates for further analysis. In future, more trials need to be performed with these inhibitors. Moreover, there are several other novel small molecule SHIP2 inhibitors identified from chemical library that need to be tested. Briefly, in this thesis, I have first time reported 8 novel small molecule SHIP2 inhibitors which could be a significant step in the discovery of new T2DM drugs for more efficient, cost effective and safe treatment of the disease with least contraindications
