TY - JOUR T1 - Adipocyte JAK2 mediates hepatic insulin sensitivity and the diabetogenic action of Growth Hormone JF - bioRxiv DO - 10.1101/076265 SP - 076265 AU - Kevin C. Corbit AU - João Paulo G. Camporez AU - Jennifer L. Tran AU - Camella G. Wilson AU - Rachel J. Perry AU - Gerald I. Schulman AU - Michael J. Jurczak AU - Ethan J. Weiss Y1 - 2016/01/01 UR - http://biorxiv.org/content/early/2016/09/20/076265.abstract N2 - For nearly 100 years, Growth Hormone (GH) has been known to regulate insulin sensitivity and risk of diabetes. However, the tissue governing the effects of GH signaling on insulin and glucose homeostasis remains unknown. Excess GH reduces fat mass and insulin sensitivity. Conversely, GH insensitivity (GHI) is associated with increased adiposity, augmented insulin sensitivity, and protection from diabetes. Here we induce adipocyte-specific GHI through conditional deletion of Jak2 (JAK2A), an obligate transducer of GH signaling. Similar to whole-body GHI, JAK2A mice had increased adiposity and extreme insulin sensitivity. Loss of adipocyte Jak2 augmented hepatic insulin sensitivity and conferred resistance to diet-induced metabolic stress without overt changes in circulating fatty acids. While GH injections induced hepatic insulin resistance in control mice, the diabetogenic action was absent in JAK2A mice. Collectively, our results show that adipose tissue governs the effects of GH on insulin and glucose homeostasis. Further, we show that JAK2 mediates liver insulin sensitivity via an extra-hepatic, adipose tissue-dependent mechanism. ER -