Kim Eun Ran, Xu Yang, Mizuno Tooru M
Division of Endocrinology & Metabolic Disease, Department of Physiology, University of Manitoba, Winnipeg, MB, Canada.
Division of Endocrinology & Metabolic Disease, Department of Physiology, University of Manitoba, Winnipeg, MB, Canada.
Behav Brain Res. 2014 Mar 15;261:60-4. doi: 10.1016/j.bbr.2013.12.005. Epub 2013 Dec 12.
Xenin is a gut hormone that reduces food intake partly by acting through the hypothalamus. However, the mechanism of hypothalamic xenin action is not fully understood. To identify xenin-regulated genes in the hypothalamus, we compared expression levels of metabolism-related genes in the hypothalamus between saline-treated control and xenin-treated mice. Intraperitoneal injection of xenin caused a significant increase in hypothalamic interleukin 1 beta (IL-1β) mRNA levels without causing a significant change in hypothalamic IL-1α mRNA levels. To further examine the possible contribution of IL-1 signaling to xenin's anorexigenic action, the effect of intraperitoneal injection of xenin on food intake was compared between wild-type and type I IL-1 receptor (IL-1RI)-deficient mice. Intraperitoneal administration of xenin (7.5 μg/g b.w.) caused a significant reduction of food intake in wild-type mice, while it failed to reduce food intake in pre-obese IL-1RI-deficient mice. These findings support the role of hypothalamic IL-1β-IL-1RI signaling in the mediation of the anorexigenic effect of xenin.
蛙皮素是一种肠道激素，它部分通过下丘脑发挥作用来减少食物摄入量。然而，下丘脑蛙皮素作用的机制尚未完全明确。为了鉴定下丘脑中受蛙皮素调节的基因，我们比较了生理盐水处理的对照小鼠和蛙皮素处理的小鼠下丘脑内代谢相关基因的表达水平。腹腔注射蛙皮素导致下丘脑白细胞介素1β（IL-1β）mRNA水平显著升高，而下丘脑IL-1α mRNA水平无显著变化。为了进一步研究IL-1信号传导对蛙皮素厌食作用的可能贡献，我们比较了野生型小鼠和I型白细胞介素1受体（IL-1RI）缺陷型小鼠腹腔注射蛙皮素对食物摄入量的影响。腹腔注射蛙皮素（7.5μg/g体重）导致野生型小鼠食物摄入量显著减少，而在肥胖前期IL-1RI缺陷型小鼠中未能减少食物摄入量。这些发现支持下丘脑IL-1β-IL-1RI信号传导在介导蛙皮素厌食效应中的作用。
