Wu Junnan, Zheng Chunxia, Wang Xiao, Yun Shifeng, Zhao Yue, Liu Lin, Lu Yuqiu, Ye Yuting, Zhu Xiaodong, Zhang Changming, Shi Shaolin, Liu Zhihong
J Clin Invest. 2015 Nov 2;125(11):4091-106. doi: 10.1172/JCI81061. Epub 2015 Oct 5.
Calcium/calcineurin signaling is critical for normal cellular physiology. Abnormalities in this pathway cause many diseases, including podocytopathy; therefore, understanding the mechanisms that underlie the regulation of calcium/calcineurin signaling is essential. Here, we showed that critical components of calcium/calcineurin signaling, including TRPC6, PPP3CA, PPP3CB, PPP3R1, and NFATC3, are the targets of the microRNA-30 family (miR-30s). We found that these 5 genes are highly expressed as mRNA, but the level of the proteins is low in normal podocytes. Conversely, protein levels were markedly elevated in podocytes from rats treated with puromycin aminonucleoside (PAN) and from patients with focal segmental glomerulosclerosis (FSGS). In both FSGS patients and PAN-treated rats, miR-30s were downregulated in podocytes. In cultured podocytes, PAN or a miR-30 sponge increased TRPC6, PPP3CA, PPP3CB, PPP3R1, and NFATC3 expression; calcium influx; intracellular Ca2+ concentration; and calcineurin activity. Moreover, NFATC3 nuclear translocation, synaptopodin degradation, integrin β3 (ITGB3) activation, and actin fiber loss, which are downstream of calcium/calcineurin signaling, were induced by miR-30 reduction but blocked by the calcineurin inhibitor FK506. Podocyte-specific expression of the miR-30 sponge in mice increased calcium/calcineurin pathway component protein expression and calcineurin activity. The mice developed podocyte foot process effacement and proteinuria, which were prevented by FK506. miR-30s also regulated calcium/calcineurin signaling in cardiomyocytes. Together, our results identify miR-30s as essential regulators of calcium/calcineurin signaling.
钙/钙调神经磷酸酶信号传导对正常细胞生理功能至关重要。该信号通路异常会引发包括足细胞病在内的多种疾病；因此，了解钙/钙调神经磷酸酶信号传导调控的潜在机制至关重要。在此，我们发现钙/钙调神经磷酸酶信号传导的关键组分，包括瞬时受体电位阳离子通道蛋白6（TRPC6）、蛋白磷酸酶3催化亚基α（PPP3CA）、蛋白磷酸酶3催化亚基β（PPP3CB）、蛋白磷酸酶3调节亚基Bα（PPP3R1）和活化T细胞核因子3（NFATC3），是微小RNA-30家族（miR-30s）的作用靶点。我们发现这5个基因的mRNA高度表达，但在正常足细胞中蛋白质水平较低。相反，在嘌呤霉素氨基核苷（PAN）处理的大鼠和局灶节段性肾小球硬化（FSGS）患者的足细胞中，蛋白质水平显著升高。在FSGS患者和PAN处理的大鼠中，足细胞中的miR-30s均下调。在培养的足细胞中，PAN或miR-30海绵增加了TRPC6、PPP3CA、PPP3CB、PPP3R1和NFATC3的表达；钙内流；细胞内Ca2+浓度；以及钙调神经磷酸酶活性。此外，钙/钙调神经磷酸酶信号传导下游的NFATC3核转位、突触足蛋白降解、整合素β3（ITGB3）活化和肌动蛋白纤维丢失，由miR-30减少诱导，但被钙调神经磷酸酶抑制剂FK506阻断。在小鼠中足细胞特异性表达miR-30海绵增加了钙/钙调神经磷酸酶信号通路组分蛋白表达和钙调神经磷酸酶活性。这些小鼠出现了足细胞足突消失和蛋白尿，FK506可预防这些症状。miR-30s还调节心肌细胞中的钙/钙调神经磷酸酶信号传导。总之，我们的结果确定miR-30s是钙/钙调神经磷酸酶信号传导的重要调节因子。
