TRPC6 channels modulate the response of pancreatic stellate cells to hypoxia
TRPC6 channels modulate the response of pancreatic stellate cells to hypoxia
复制标题
DOI：
10.1007/s00424-017-2057-0
复制
发表时间：
2017-12-01
影响因子：
4.5
通讯作者：
Schwab, Albrecht
中科院分区：
文献类型：
--
作者：
Nielsen, Nikolaj;Kondratska, Kateryna;Schwab, Albrecht
胰腺癌的特征是大量纤维化（结缔组织增生），主要是由激活的胰腺星状细胞（PSCs）引起的。这导致低氧肿瘤微环境通过刺激PSCs分泌生长因子和趋化因子进一步增强其活化。由于它们中的许多通过g蛋白偶联受体（gpcr）引发其作用，因此我们测试了TRPC6通道（许多g蛋白偶联受体途径的效应蛋白）是否为PSCs的缺氧激活所必需。到目前为止，离子通道在psc中的功能几乎未被探索。qPCR结果显示，TRPC6通道是小鼠psc原代培养中最丰富的TRPC通道之一。通过比较TRPC6（-/-）小鼠和野生型（wt）幼崽的PSCs来评估TRPC6通道功能。细胞迁移、Ca2+信号和细胞因子分泌被分析为PSC激活的读数。用1% O-2或二甲基氧基酰甘氨酸（DMOG）化学孵育PSCs 24 h诱导缺氧。PSCs在缺氧条件下迁移速度更快。由于自分泌刺激减少，在缺氧条件下，TRPC6(-/-) PSCs无法将其迁移速度提高到与wt PSCs相同的水平。这种缺陷不能通过血小板源性生长因子的刺激来克服。与这些结果一致，缺氧条件下wt细胞的钙内流增加，而TRPC6(-/-) PSCs则没有增加。我们认为，在缺氧触发的自分泌刺激途径中，PSCs的TRPC6通道是主要的效应蛋白。
Pancreatic cancer is characterized by a massive fibrosis (desmoplasia), which is primarily caused by activated pancreatic stellate cells (PSCs). This leads to a hypoxic tumor microenvironment further reinforcing the activation of PSCs by stimulating their secretion of growth factors and chemokines. Since many of them elicit their effects via G-protein-coupled receptors (GPCRs), we tested whether TRPC6 channels, effector proteins of many G-protein-coupled receptor pathways, are required for the hypoxic activation of PSCs. Thus far, the function of ion channels in PSCs is virtually unexplored. qPCR revealed TRPC6 channels to be one of the most abundant TRPC channels in primary cultures of murine PSCs. TRPC6 channel function was assessed by comparing PSCs from TRPC6(-/-) mice and wildtype (wt) littermates. Cell migration, Ca2+ signaling, and cytokine secretion were analyzed as readout for PSC activation. Hypoxia was induced by incubating PSCs for 24 h in 1% O-2 or chemically with dimethyloxalylglycine (DMOG). PSCs migrate faster in response to hypoxia. Due to reduced autocrine stimulation, TRPC6(-/-) PSCs fail to increase their rate of migration to the same level as wt PSCs under hypoxic conditions. This defect could not be overcome by the stimulation with platelet-derived growth factor. In line with these results, calcium influx is increased in wt but not TRPC6(-/-) PSCs under hypoxia. We conclude that TRPC6 channels of PSCs are major effector proteins in an autocrine stimulation pathway triggered by hypoxia.