Islets RNA-seq from male C57Bl/6J on ketogenic diet

A ketogenic diet (KD) is a very low-carbohydrate, very high-fat diet recently proposed to treat obesity and type 2 diabetes. While KD grows in popularity, its effects on metabolic health are understudied. (here) We show that, while KD protects against weight gain and induces weight loss, over long-term, mice develop hyperlipidemia, hepatic steatosis, and severe glucose intolerance. Unlike HFD-fed mice, KD mice are not insulin resistant and have low levels of insulin. Hyperglycemic clamp and ex vivo GSIS revealed cell-autonomous and whole-body impairments in insulin secretion. Major ER/Golgi stress and disrupted ER-Golgi protein trafficking was indicated by transcriptomic profiling of KD islets and confirmed by electron micrographs showing a dilated and fragmented Golgi network compatible with defects in insulin granule biogenesis and secretion. Overall, our results suggest long-term KD leads to multiple aberrations of metabolic parameters that caution its systematic use as a health promoting dietary intervention. Overall design: Mice were place on one of 3 diets for 9 months, a 10% low fat control diet, a 60% high fat diet, and an 89.9% fat ketogenic diet. At sacrifice, islets were isolated and snap frozen. RNA was extracted and sequenced to compare how a ketogenic diet affects gene expression in the in islets.