title: IL-6 induces lipolysis and mitochondrial dysfunction, but does not affect insulin-mediated glucose transport in 3T3-L1 adipocytes.
abstract: Interleukin-6 (IL-6) has emerged as an important cytokine involved in the regulation of metabolism. However, the role of IL-6 in the etiology of obesity and insulin resistance is not fully understood. Mitochondria are key organelles of energy metabolism, and there is growing evidence that mitochondrial dysfunction plays a crucial role in the pathogenesis of obesity-associated insulin resistance. In this study, we determined the direct effect of IL-6 on lipolysis in adipocytes, and the effects of IL-6 on mitochondrial function were investigated. We found that cells treated with IL-6 displayed fewer lipids and an elevated glycerol release rate. Further, IL-6 treatment led to decreased mitochondrial membrane potential, decreased cellular ATP production, and increased intracellular ROS levels. The mitochondria in IL-6-treated cells became swollen and hollow with reduced or missing cristae. However, insulin-stimulated glucose transport was unaltered. PGC-1α, NRF1, and mtTFA mRNA levels were markedly increased, and the mitochondrial contents were also increased. Our results demonstrate that IL-6 can exert a direct lipolytic effect and induce mitochondrial dysfunction. However, IL-6 did not affect insulin sensitivity in adipocytes in vitro. We deduce that in these cells, enhanced mitochondrial biogenesis might play a compensatory role in glucose transport.
authors: Department of Pediatrics, Nanjing Maternal and Child Health Hospital of Nanjing Medical University, Nanjing, China.
authors: Chenbo
authors: C
authors: Ji
authors: Xiaohui
authors: X
authors: Chen
authors: Chunlin
authors: C
authors: Gao
authors: Liuhong
authors: L
authors: Jiao
authors: Jianguo
authors: J
authors: Wang
authors: Guangfeng
authors: G
authors: Xu
authors: Hailong
authors: H
authors: Fu
authors: Xirong
authors: X
authors: Guo
authors: Yaping
authors: Y
authors: Zhao
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D001692:Biological Transport; D018929:Cell Culture Techniques; D004347:Drug Interactions; D005947:Glucose / Q000378:metabolism*; D051246:Glucose Transport Proteins, Facilitative / Q000378:metabolism*; D007328:Insulin / Q000494:pharmacology*; D015850:Interleukin-6 / Q000378:metabolism / Q000494:pharmacology*; D008066:Lipolysis / Q000187:drug effects*; D051379:Mice; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D051246:Glucose Transport Proteins, Facilitative; D007328:Insulin; D015850:Interleukin-6; D017382:Reactive Oxygen Species; D005947:Glucose