Dexamethasone-induced Krüppel-like factor 9 expression promotes hepatic gluconeogenesis and hyperglycemia
Cui A1, Fan H1, Zhang Y1, Zhang Y1, Niu D1, Liu S2, Liu Q2, Ma W3, Shen Z2, Shen L1, Liu Y1, Zhang H1, Xue Y1, Cui Y1, Wang Q4, Xiao X5, Fang F1, Yang J3, Cui Q3, Chang Y1,6
J Clin Invest. 2019 Apr 29;129(6):2266-2278
Chronic glucocorticoid therapy has serious side effects, including diabetes and fatty liver. However, the molecular mechanisms responsible for steroid-induced diabetes remain largely enigmatic. Here, we show that hepatic Krüppel-like factor 9 (Klf9) gene expression is induced by dexamethasone and fasting. The overexpression of Klf9 in primary hepatocytes strongly stimulated Pgc1a gene expression through direct binding to its promoter, thereby activating the gluconeogenic program. However, Klf9 mutation abolished the stimulatory effect of dexamethasone on cellular glucose output. Adenovirus-mediated overexpression of KLF9 in the mouse liver markedly increased blood glucose levels and impaired glucose tolerance. Conversely, both global Klf9-mutant mice and liver-specific Klf9-deleted mice displayed fasting hypoglycemia. Moreover, the knockdown of Klf9 in the liver in diabetic mouse models, including ob/ob and db/db mice, markedly lowered fasting blood glucose levels. Notably, hepatic Klf9 deficiency in mice alleviated hyperglycemia induced by chronic dexamethasone treatment. These results suggest a critical role for KLF9 in the regulation of hepatic glucose metabolism and identify hepatic induction of KLF9 as a mechanism underlying glucocorticoid therapy-induced diabetes.