Adipose-specific deletion of Kif5b exacerbates obesity and insulin resistance in a mouse model of diet-induced obesity

Recent studies have shown that KIF5B (conventional kinesin heavy chain) mediates glucose transporter type 4 translocation and adiponectin secretion in 3T3-L1 adipocytes, suggesting an involvement of KIF5B in the homeostasis of metabolism. However, the in vivo physiologic function of KIF5B in adipose tissue remains to be determined. In this study, adipose-specific Kif5b knockout (F-K5bKO) mice were generated using the Cre-LoxP strategy. F-K5bKO mice had similar body weights to controls fed on a standard chow diet. However, F-K5bKO mice had hyperlipidemia and significant glucose intolerance and insulin resistance. Deletion of Kif5b aggravated the deleterious impact of a high-fat diet (HFD) on body weight gain, hepatosteatosis, glucose tolerance, and systematic insulin sensitivity. These changes were accompanied by impaired insulin signaling, decreased secretion of adiponectin, and increased serum levels of leptin and proinflammatory adipokines. F-K5bKO mice fed on an HFD exhibited lower energy expenditure and thermogenic dysfunction as a result of whitening of brown adipose due to decreased mitochondria biogenesis and down-regulation of key thermogenic gene expression. In conclusion, selective deletion of Kif5b in adipose tissue exacerbates HFD-induced obesity and its associated metabolic disorders, partly through a decrease in energy expenditure, dysregulation of adipokine secretion, and insulin signaling.-Cui, J., Pang, J., Lin, Y.-J., Gong, H., Wang, Z.-H., Li, Y.-X., Li, J., Wang, Z., Jiang, P., Dai, D.-P., Li, J., Cai, J.-P., Huang, J.-D., Zhang, T.-M. Adipose-specific deletion of Kif5b exacerbates obesity and insulin resistance in a mouse model of diet-induced obesity.