Vázquez-Carretero María Dolores, Carvajal Ana Eloisa, Serrano-Morales José Manuel, García-Miranda Pablo, Ilundain Anunciación Ana, Peral María José
Departamento de Fisiología, Facultad de Farmacia, Universidad de Sevilla, 41012, Sevilla, Spain.
J Bioenerg Biomembr. 2016 Dec;48(6):569-579. doi: 10.1007/s10863-016-9689-1. Epub 2016 Nov 23.
The expression of the phosphoinositides phosphatases Synaptojanins (Synjs) 1 and 2 has been shown in brain and in some peripheral tissues, but their expression in the intestine has not been reported. Herein we show that the small and large intestine express Synj1 and Synj2. Their mRNA levels, measured by RT-PCR, are not affected by development in the small intestine but in the colon they increase with age. Immunostaining assays reveal that both Synjs localize at the apical domain of the epithelial cells and at the lamina propria at sites also expressing the neuron marker calretinin. Synj2 staining at the lamina propria is fainter than that of Synj1. In colonocytes Synjs are at the apical membrane and cytosolic membrane vesicles. Synj2 is also at the mitochondria. Western blots reveal that the intestinal mucosa expresses at least two Synj1 (170- and 139-kDa) and two Synj2 (160- and 148-kDa) isoforms. The observations suggest that Synj1-170, Synj2-160, and Synj2-148 in colonocytes, might participate in processes that take place mainly at the apical domain of the epithelial cells whereas Synj1-139 in those at the enteric nervous system. Experimental colitis augments the mRNA abundance of both Synjs in colon but only Synj2 mRNA levels are increased in colon tumors. In conclusion, as far as we know, this is the first report showing expression, location and isoforms of Synj1 and Synj2 in the small and large intestine and that they might participate in intestinal pathology.
磷酸肌醇磷酸酶突触素（Synjs）1和2已在脑和一些外周组织中被证实有表达，但它们在肠道中的表达尚未见报道。在此我们发现，小肠和大肠均表达Synj1和Synj2。通过逆转录聚合酶链反应（RT-PCR）检测，它们的mRNA水平在小肠中不受发育影响，但在结肠中会随年龄增加。免疫染色分析显示，两种突触素均定位于上皮细胞的顶端区域以及固有层中也表达神经元标志物钙视网膜蛋白的部位。固有层中Synj2的染色比Synj1淡。在结肠细胞中，突触素位于顶端膜和胞质膜囊泡。Synj2也存在于线粒体。蛋白质免疫印迹显示，肠黏膜表达至少两种Synj1（170 kDa和139 kDa）和两种Synj2（160 kDa和148 kDa）亚型。这些观察结果表明，结肠细胞中的Synj1-170、Synj2-160和Synj2-148可能参与主要发生在上皮细胞顶端区域的过程，而肠神经系统中的Synj1-139则参与相关过程。实验性结肠炎会增加结肠中两种突触素的mRNA丰度，但只有Synj2的mRNA水平在结肠肿瘤中升高。总之，据我们所知，这是首次报道Synj1和Synj2在小肠和大肠中的表达、定位及亚型，且它们可能参与肠道病理过程。
