Skeletal muscle enhancer interactions identify genes controlling whole-body metabolism.

Obesity and type 2 diabetes (T2D) are metabolic disorders influenced by lifestyle and genetic factors that are characterized by insulin resistance in skeletal muscle, a prominent site of glucose disposal. Numerous genetic variants have been associated with obesity and T2D, of which the majority are located in non-coding DNA regions. This suggests that most variants mediate their effect by altering the activity of gene-regulatory elements, including enhancers.

Overexpression of cyclooxygenase-2 in adipocytes reduces fat accumulation in inguinal white adipose tissue and hepatic steatosis in high-fat fed mice.

Cyclooxygenases are known as important regulators of metabolism and immune processes via conversion of C20 fatty acids into various regulatory lipid mediators, and cyclooxygenase activity has been implicated in browning of white adipose tissues. We generated transgenic (TG) C57BL/6 mice expressing the Ptgs2 gene encoding cyclooxygenase-2 (COX-2) in mature adipocytes. TG mice fed a high-fat diet displayed marginally lower weight gain with less hepatic steatosis and a slight improvement in insulin sensitivity, but no difference in glucose tolerance.

A safflower oil based high-fat/high-sucrose diet modulates the gut microbiota and liver phospholipid profiles associated with early glucose intolerance in the absence of tissue inflammation.

Scope: Omega-6 (n-6) PUFA-rich diets are generally considered obesogenic in rodents. Here, we examined how long-term intake of a high-fat/high-sucrose (HF/HS) diet based on safflower oil affected metabolism, inflammation, and gut microbiota composition.

Methods And Results: We fed male C57BL/6J mice a HF/HS diet based on safflower oil-rich in n-6 PUFAs-or a low-fat/low-sucrose diet for 40 wk.