Peroxisome Proliferator-Activated Receptor γ-Mediated Inhibition on Hypoxia-Triggered Store-Operated Calcium Entry A Caveolin-1-Dependent Mechanism
Peroxisome Proliferator-Activated Receptor γ-Mediated Inhibition on Hypoxia-Triggered Store-Operated Calcium Entry A Caveolin-1-Dependent Mechanism
复制标题
过氧化物酶体增殖物激活受体γ介导的对缺氧触发的钙离子进入的抑制。
DOI：
10.1165/rcmb.2015-0002oc
复制
发表时间：
2015-12-01
影响因子：
6.4
通讯作者：
Wang, Jian
中科院分区：
文献类型：
--
作者：
Yang, Kai;Lu, Wenju;Wang, Jian
我们之前的出版物表明，过氧化物酶体增殖物激活受体γ（PPARγ）通过靶向大鼠远端肺动脉平滑肌细胞（PASMC）中钙池操纵的钙内流（SOCE）来抑制慢性缺氧（CH）诱导的肺动脉高压的发病机制。在这项研究中，我们的目的是确定膜支架蛋白 Caveolin-1 在 PPAR gamma 对 SOCE 的抑制过程中的作用。成年（6-8 周）雄性 Wistar 大鼠（200-250 g）暴露于 CH（10% O-2）21 天，以建立 CH 诱导的肺动脉高压。原代培养的大鼠远端PASMCs用于分子生物学实验。首先，低氧暴露导致远端肺动脉和 PASMC 中的 Caveolin-1 蛋白表达分别增加 2.5 倍和 1 倍。其次，通过Mn2+猝灭和细胞外Ca2+恢复实验测量，有效敲低caveolin-1可分别显着降低缺氧诱导的SOCE，分别为58.2%和41.5%。这些结果表明，caveolin-1 是 SOCE 的重要调节因子，缺氧上调的 Caveolin-1 在很大程度上解释了 PASMC 中缺氧升高的 SOCE。然后，通过使用高效PPARγ激动剂GW1929，我们检测到PPARγ激活在缺氧下分别抑制SOCE和caveolin-1蛋白62.5％和59.8％，这表明caveolin-1也是PASMCs中PPARγ抑制SOCE过程中的关键靶点。此外，通过使用针对PPARγ和caveolin-1的有效小干扰RNA以及PPARγ拮抗剂T0070907，我们观察到PPARγ通过促进其溶酶体降解而对caveolin-1蛋白发挥抑制作用，而不影响信使RNA水平。 PPAR gamma 至少部分通过抑制 PASMC 中的细胞 Caveolin-1 蛋白来抑制 SOCE。
Our previous publication demonstrated that peroxisome proliferator-activated receptor gamma (PPAR gamma) inhibits the pathogenesis of chronic hypoxia (CH)-induced pulmonary hypertension by targeting store-operated calcium entry (SOCE) in rat distal pulmonary arterial smooth muscle cells (PASMCs). In this study, we aim to determine the role of a membrane scaffolding protein, caveolin-1, during the suppressive process ofPPAR gamma on SOCE. Adult (6-8 weeks) male Wistar rats (200-250 g) were exposed to CH (10% O-2) for 21 days to establish CH-induced pulmonary hypertension. Primary cultured rat distal PASMCs were applied for the molecular biological experiments. First, hypoxic exposure led to 2.5-fold and 1-fold increases of caveolin-1 protein expression in the distal pulmonary arteries and PASMCs, respectively. Second, effective knockdown of caveolin-1 significantly reduced hypoxia-induced SOCE for 58.2% and 41.5%, measured by Mn2+ quenching and extracellular Ca2+ restoration experiments, respectively. These results suggested that caveolin-1 acts as a crucial regulator of SOCE, and hypoxia-up-regulated caveolin-1 largely accounts for hypoxia-elevated SOCE in PASMCs. Then, by using a high-potency PPAR gamma agonist, GW1929, we detected that PPAR gamma activation inhibited SOCE and caveolin-1 protein for 62.5% and 59.8% under hypoxia, respectively, suggesting that caveolin-1 also acts as a key target during the suppressive process of PPAR gamma on SOCE in PASMCs. Moreover, by using effective small interfering RNAs against PPAR gamma and caveolin-1, and PPAR gamma antagonist, T0070907, we observed that PPAR gamma plays an inhibitory role on caveolin-1 protein by promoting its lysosomal degradation, without affecting the messenger RNA level. PPAR gamma inhibits SOCE, at least partially, by suppressing cellular caveolin-1 protein in PASMCs.