Cammisotto Philippe G, Bendayan Moise, Sané Alain, Dominguez Michel, Garofalo Carole, Levy Emile
Departments of Pathology and Cell Biology, University of Montreal, 2900, Bd Edouard-Montpetit, Montreal, Canada H3T 1J4.
Int J Cell Biol. 2010;2010:928169. doi: 10.1155/2010/928169. Epub 2010 Apr 29.
Gastric Leptin is absorbed by duodenal enterocytes and released on the basolateral side towards the bloodstream. We investigated in vitro some of the mechanisms of this transport. Caco-2/15 cells internalize leptin from the apical medium and release it through transcytosis in the basal medium in a time- temperature-dependent and saturable fashion. Leptin receptors are revealed on the apical brush-border membrane of the Caco-2 cells. RNA-mediated silencing of the receptor led to decreases in the uptake and basolateral release. Leptin in the basal medium was found bound to the soluble form of its receptor. An inhibitor of clathrin-dependent endocytosis (chlorpromazine) decreased leptin uptake. Confocal immunocytochemistry and the use of brefeldin A and okadaic acid revealed the passage of leptin through the Golgi apparatus. We propose that leptin transcytosis by intestinal cells depends on its receptor, on clathrin-coated vesicles and transits through the Golgi apparatus.
胃瘦素被十二指肠肠上皮细胞吸收，并在基底外侧释放进入血液循环。我们在体外研究了这种转运的一些机制。Caco-2/15细胞从顶端培养基中摄取瘦素，并通过转胞吞作用以时间-温度依赖性和饱和性的方式将其释放到基底培养基中。在Caco-2细胞的顶端刷状缘膜上发现了瘦素受体。RNA介导的受体沉默导致摄取和基底外侧释放减少。发现基底培养基中的瘦素与其受体的可溶性形式结合。网格蛋白依赖性内吞作用的抑制剂（氯丙嗪）减少了瘦素的摄取。共聚焦免疫细胞化学以及布雷菲德菌素A和冈田酸的使用揭示了瘦素通过高尔基体的过程。我们提出，肠道细胞的瘦素转胞吞作用取决于其受体、网格蛋白包被囊泡，并通过高尔基体转运。
