Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea.
Metabolism. 2011 Dec;60(12):1664-72. doi: 10.1016/j.metabol.2011.04.008. Epub 2011 May 31.
Leptin and adiponectin are hormones secreted from adipocytes that have important roles in metabolism and energy homeostasis. This review evaluates the effects of leptin and adiponectin on β-cell function by analyzing and compiling results from human clinical trials and epidemiologic studies as well as in vitro and in vivo experiments. Leptin has been shown to inhibit ectopic fat accumulation and thereby prevent β-cell dysfunction and protect the β-cell from cytokine- and fatty acid-induced apoptosis. However, leptin suppresses insulin gene expression and secretion as well as glucose transport into the β-cell. Adiponectin stimulates insulin secretion by enhancing exocytosis of insulin granules and upregulating the expression of the insulin gene; however, this effect depends on the prevailing glucose concentration and status of insulin resistance. In addition, adiponectin has antiapoptotic properties in β-cells. Available evidence concerning the role of these adipokines on insulin secretion, insulin gene expression, and apoptosis is not always entirely consistent; and many fundamental questions remain to be answered by future studies.
瘦素和脂联素是由脂肪细胞分泌的激素，在代谢和能量平衡中具有重要作用。本综述通过分析和综合人类临床试验和流行病学研究以及体外和体内实验的结果，评估了瘦素和脂联素对β细胞功能的影响。瘦素已被证明可抑制异位脂肪积累，从而防止β细胞功能障碍并保护β细胞免受细胞因子和脂肪酸诱导的细胞凋亡。然而，瘦素抑制胰岛素基因的表达和分泌以及葡萄糖向β细胞的转运。脂联素通过增强胰岛素颗粒的胞吐作用和上调胰岛素基因的表达来刺激胰岛素分泌；然而，这种作用取决于葡萄糖浓度和胰岛素抵抗的状态。此外，脂联素在β细胞中具有抗凋亡作用。关于这些脂肪因子对胰岛素分泌、胰岛素基因表达和细胞凋亡作用的现有证据并不完全一致；许多基本问题仍有待未来的研究来回答。
