Targeting protein tyrosine phosphatase to enhance insulin action for the potential treatment of diabetes.

The increasing prevalence of type 2 diabetes has sparked interest in the development of agents that treat and prevent the disease. Mounting evidence indicates that protein tyrosine phosphatase (PTP)1B negatively regulates insulin and leptin signaling making it a prime target for enhancing insulin sensitivity and controlling body mass. Despite intense efforts, development of orally bioavailable small-molecule PTP1B inhibitors has been a challenge.

1,2,3,4-Tetrahydroisoquinolinyl sulfamic acids as phosphatase PTP1B inhibitors.

High-throughput screening of the P&GP corporate repository against several protein tyrosine phosphatases identified the sulfamic acid moiety as potential phosphotyrosine mimetic. Incorporation of the sulfamic acid onto a 1,2,3,4-tetrahydroisoquinoline scaffold provided a promising starting point for PTP1B inhibitor design.

A nonspecific phosphotyrosine phosphatase inhibitor, bis(maltolato)oxovanadium(IV), improves glucose tolerance and prevents diabetes in Zucker diabetic fatty rats.

The molecular basis of insulin resistance, a major risk factor for development of Type II diabetes, involves defective insulin signaling. Insulin-mediated signal transduction is negatively regulated by the phosphotyrosine phosphatase, PTP1B, and numerous studies have demonstrated that organo-vanadium compounds, which are nonselective phosphotyrosine phosphatase inhibitors, have insulin-mimetic properties. However, whether or not vanadium compounds can prevent the transition from insulin resistance to overt diabetes is unknown.