Steroidogenic Acute Regulatory Protein (StAR) Overexpression Reduces Inflammation and Insulin Resistance in Obese Mice.

Abstract

Steroidogenic acute regulatory protein (StAR), a mitochondrial cholesterol delivery protein, plays a beneficial role in hyperlipidemia, NAFLD, and endothelial inflammation. Elevated circulating fatty acids and low grade inflammation are known as key risk factors of insulin resistance and type 2 diabetes. In the present study, C57BL/6J mice were fed with HFD and infected with recombinant adenovirus expressing StAR by tail-vein injection. Intraperitoneal glucose/insulin tolerance test was performed to assess the insulin sensitivity. Morphological analysis and intramuscular lipid determination were used to illustrate the adipose hypertrophy and ectopic fat accumulation in skeletal muscle. The levels of inflammatory factor and nitric oxide were determined by ELISA and classic Griess reagent methods, respectively. The fatty acids composition was analysis using gas chromatography-mass spectrometry (GC-MS). The expression of genes associated with inflammation and insulin resistance were determined by Western blotting and qPCR to elucidate the underlying mechanism. We demonstrated that StAR overexpression ameliorated insulin resistance and systemic inflammatory response with the reduction of adipose hypertrophy and intramuscular lipid in HFD-fed mice. In addition, StAR overexpression increased serum unsaturated fatty acids (UFAs) and PPARγ expression in muscle and adipose tissue of obese mice. In conclusion, StAR may activate PPARγ by increasing UFAs, which leads to a protective role in systemic inflammation and insulin resistance in obese mice. J. Cell. Biochem. 118: 3932-3942, 2017. © 2017 Wiley Periodicals, Inc.

• Authors: Yanyan Qiu, Xianxian Sui, Shengxuan Cao, Xiaobo Li, Yanxia Ning, Songmei Wang, Lianhua Yin, Xiuling Zhi
• Journal: Journal of cellular biochemistry (J Cell Biochem) Vol. 118 Issue 11 Pg. 3932-3942 (11 2017) ISSN: 1097-4644 [Electronic] United States
• PMID: 28402022 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2017 Wiley Periodicals, Inc.

Chemical References

• Dietary Fats
• Fatty Acids, Unsaturated
• PPAR gamma
• Phosphoproteins
• steroidogenic acute regulatory protein
• Nitric Acid

Topics

• Adipose Tissue (metabolism, pathology)
• Animals
• Dietary Fats (adverse effects, pharmacology)
• Fatty Acids, Unsaturated (blood)
• Inflammation
• Insulin Resistance
• Male
• Mice
• Muscle, Skeletal (metabolism, pathology)
• Nitric Acid (blood)
• Obesity (chemically induced, genetics, metabolism, pathology)
• PPAR gamma (genetics, metabolism)
• Phosphoproteins (biosynthesis, genetics)