Project description:Illuminating the mechanisms controlling glucose homeostasis may deepen our understanding of the pathogenesis of T2DM and provide new therapeutic strategies for T2DM in future. As reported, Dyrk1b is a pleiotropic protein and its genetic mutations associate with blood glucose levels. Yet, the role of Dyrk1b in glucose metabolism is not well understood. Herein, we find that hepatic Dyrk1b overexpression in mice impairs the glucose tolerance and insulin resistance, whereas global Dyrk1b deficiency improves glucose metabolism of mcie. Dyrk1b overexpression in vitro blunts insulin signalling and glucose uptake. Collectively, our study uncovers a novel link between hepatic Dyrk1b and whole body glucose homeostasis.
Project description:Illuminating the mechanisms controlling glucose homeostasis may deepen our understanding of the pathogenesis of T2DM and provide new therapeutic strategies for T2DM in future. As reported, Dyrk1b is a pleiotropic protein and its genetic mutations associate with blood glucose levels. Yet, its role in glucose metabolism remains to be established. Herein, we invetigate the role of Dyrk1b in glucose metabolism and the underlying mechanisms. We find that hepatic Dyrk1b overexpression in mice impairs the glucose tolerance and insulin resistance, whereas global Dyrk1b deficiency improves glucose metabolism of mcie. Dyrk1b overexpression in vitro blunts insulin signalling and glucose uptake. Quantitative proteomic analyses further reveal that Wbp2 is a putative target of Dyrk1b. Importantly, hepatic Wbp2 restoration rescues the glucose homeostasis in Dyrk1b overexpression mice. Additionally, ATAC-seq analyses indicate Dyrk1b’s role in remodelling hepatic chromatin landscape. Collectively, our study uncovers a novel link between hepatic Dyrk1b and whole body glucose homeostasis via modulation of hepatic Wbp2 expression.
Project description:One of the causes of hyperglycemia in type 2 diabetes is elevated hepatic glucose production. AKT-FOXO1 pathway is primarily involved in the hormonal upregulation of this process, and pharmacological or genetic inhibition of this pathway prevents diabetes in animal models. Here we report that DYRK1B regulates FoxO1 function through phosphorylation to regulate hepatic glucose metabolism. DYRK1B expression is induced by fasting and in diabetic mice. DYRK1B promoted hepatic gluconeogenesis and glucose intolerance in in vivo and in vitro model systems. Liver-specific DYRK1B conditional knockout mice were protected from diet-induced hyperglycemia. Mechanistically, DYRK1B interacted with and phosphorylated FoxO1, primarily at T467S468, which is required for its nuclear localization. DYRK1B inhibited AKT mediated FoxO1 phosphorylation at T24 and S256 and enhanced its nuclear retention. DYRK1B mediated phosphorylation of FoxO1 enhanced the expression of gluconeogenic genes and promoted gluconeogenesis. Treatment with DYRK1B pharmacological inhibitor AZ191 significantly lowered blood glucose levels in diabetic mice. We conclude that DYRK1B is a regulator of glucose metabolism, and its pharmacological inhibition could serve as therapeutic target for treating diabetes.
Project description:One of the causes of hyperglycemia in type 2 diabetes is elevated hepatic glucose production. AKT-FOXO1 pathway is primarily involved in the hormonal upregulation of this process, and pharmacological or genetic inhibition of this pathway prevents diabetes in animal models. Here we report that DYRK1B regulates FoxO1 function through phosphorylation to regulate hepatic glucose metabolism. DYRK1B expression is induced by fasting and in diabetic mice. DYRK1B promoted hepatic gluconeogenesis and glucose intolerance in in vivo and in vitro model systems. Liver-specific DYRK1B conditional knockout mice were protected from diet-induced hyperglycemia. Mechanistically, DYRK1B interacted with and phosphorylated FoxO1, primarily at T467S468, which is required for its nuclear localization. DYRK1B inhibited AKT mediated FoxO1 phosphorylation at T24 and S256 and enhanced its nuclear retention. DYRK1B mediated phosphorylation of FoxO1 enhanced the expression of gluconeogenic genes and promoted gluconeogenesis. Treatment with DYRK1B pharmacological inhibitor AZ191 significantly lowered blood glucose levels in diabetic mice. We conclude that DYRK1B is a regulator of glucose metabolism, and its pharmacological inhibition could serve as therapeutic target for treating diabetes.
Project description:Dual-specificity tyrosine phosphorylation-regulated kinase 1B (DYRK1B), a member of the CMGC group of kinase, is associated with metabolic syndrome. However, the molecular mechanisms involved remain elusive. In this study, we demonstrate that Dyrk1b expression is induced in liver by fasting and in diabetic mice. Using both in vivo and in vitro studies, we show that DYRK1B promotes hepatic gluconeogenesis and glucose intolerance. Liver-specific Dyrk1b conditional knockout mice were protected from diet-induced hyperglycemia. Mechanistically, DYRK1B interacts with and phosphorylates FOXO1, primarily at Thr467/Ser468, which is essential for its nuclear localization. Additionally, DYRK1B inhibits AKT mediated FOXO1 phosphorylation at Thr24 and Ser256, thereby enhancing its nuclear retention. DYRK1B mediated phosphorylation enhances the expression of gluconeogenic genes and promotes gluconeogenesis. Further, a pharmacological inhibitor of DYRK1B significantly reduced blood glucose levels in diabetic mice. Collectively, these findings offer new insights into DYRK1B’s role in the glucose metabolism and identify it as a new therapeutic target for treating diabetes.