Gene regulation of RMR-related DNAJC6 on adipogenesis and mitochondria function in 3T3-L1 preadipocytes

Abstract

In the pilot GWAS of children obesity, DNAJC6 gene was found as a regulator for resting metabolic rate (RMR) and obesity in children aged 8–9 years. To investigate whether DNAJC6 gene regulated obesity and energy metabolism, the physiological mechanisms during adipogenesis of 3T3-L1 preadipocytes were confirmed after DNAJC6 gene was overexpressed or inhibited. Overexpressing DNAJC6 gene maintained a 3T3-L1 preadipocyte status during cell differentiation (MTT, ORO, DAPI/BODIPY). It suppressed adipogenesis and adipokine production (leptin, adiponectin), insulin signaling with IRS-GLUT4 system (RT-PCR, Western blotting), and mitochondrial function (Mito Stress Test). DNAJC6 overexpressed cells inhibited mTOR expression, but maintained LC3 expression at a high level, indicating that autophagy occurred and energy was obtained. However, when DNAJC6 gene was inhibited, fat synthesis factor was highly expressed during differentiation (PPARr, C/EBPa, aP2, etc) and the intracellular stress level increased accordingly, which affected the reduction of reserve respiratory capacity during mitochondrial respiration. Our study confirmed gene regulation of DNAJC6, overexpression or inhibition, affects adipogenesis with energy metabolism and mitochondrial functions. This basic data can be used for clinic obesity studies to control an energy imbalance.