DYRK1A inhibition restores pancreatic functions and improves glucose metabolism in a preclinical model of type 2 diabetes.

OBJECTIVES: Insulin deficiency caused by the loss of β cells and/or impaired insulin secretion is a key factor in the pathogenesis of type 2 diabetes (T2D). The restoration of β cell number and function is thus a promising strategy to combat diabetes. Dual-specificity tyrosine-regulated kinase 1A (DYRK1A) has been shown to regulate human β cell proliferation. DYRK1A inhibitors are potential therapeutic tools, due to their ability to induce β cell proliferation. However, their anti-diabetic effects in the complex setting of type 2 diabetes remains unexplored. The aim of this study was to determine the impact of chronic DYRK1A inhibition on the remission of diabetes in pre-diabetic and overtly diabetic Goto-Kakizaki (GK) rats. METHODS: We assessed the impact of in vivo treatment with a DYRK1A inhibitor, Leucettinib-92, on β cell proliferation and insulin secretion in GK rats. Further, we evaluated the effects of long-term Leucettinib-92 treatment on the whole-body glucose metabolism in overtly diabetic GK rats through the assessment of fasting and post-absorptive glycemia, glucose tolerance and insulin sensitivity. RESULTS: Short-term in vivo treatment of prediabetic GK rats with Leucettinb-92 stimulated β cell proliferation in vivo, and sustainably prevented the development of overt hyperglycemia. Long-term treatment of adult GK rats with established diabetes increased the β cell mass and reduced basal hyperglycemia. Leucettinib-92 treatment also improved glucose tolerance, and glucose-induced insulin secretion in vivo. CONCLUSIONS: We show that DYRK1A inhibition restores the β cell mass and function in a preclinical model of T2D, leading to the improvement of body's global glucose homeostasis.