BMP4 inhibits PDGF-induced proliferation and collagen synthesis via PKA-mediated inhibition of calpain-2 in pulmonary artery smooth muscle cells
BMP4 inhibits PDGF-induced proliferation and collagen synthesis via PKA-mediated inhibition of calpain-2 in pulmonary artery smooth muscle cells
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DOI：
10.1152/ajplung.00260.2016
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发表时间：
2017-05-01
影响因子：
4.9
通讯作者：
Su, Yunchao
中科院分区：
文献类型：
--
作者：
Cai, Pengcheng;Kovacs, Laszlo;Su, Yunchao
在本研究中，我们研究了骨形态发生蛋白 4 (BMP4) 对 PDGF 诱导的肺动脉平滑肌细胞 (PASMC) 细胞增殖和胶原合成的影响。在存在和不存在 BMP4 的情况下，正常人 PASMC 在有或没有 PDGF-BB 的情况下孵育 0.5 至 24 小时。然后测量胶原蛋白-I、p-Smad2/3、p-Smad1/5 和细胞内活性 TGF-1 的蛋白质水平、钙蛋白酶活性和细胞增殖。结果表明，BMP4 诱导 p-Smad1/5 增加，但对对照 PASMC 中胶原蛋白 I、p-Smad2/3 的蛋白水平以及细胞内活性 TGF-β 1 和钙蛋白酶活性没有影响。然而，BMP4 减弱了暴露于 PDGF-BB 的 PASMC 中细胞增殖和胶原蛋白 I、p-Smad2/3 的蛋白水平以及细胞内活性 TGF-β 1 和钙蛋白酶活性的增加。此外，BMP4 增加了 PKA 活性，而 PKA 的抑制则阻止了 BMP4 对正常 PASMC 中 PDGF-BB 诱导的钙蛋白酶激活的抑制作用。 PKA 激活剂毛喉素再现了 BMP4 对 PDGF 诱导的钙蛋白酶激活的抑制作用。此外，BMP4 还可阻止正常 PASMC 中 PDGF 诱导的 calpain-2 丝氨酸 369 磷酸化降低。最后，BMP4 不会减弱 PDGF 诱导的细胞增殖、I 型胶原蛋白水平和钙蛋白酶激活的增加，也不会诱导 PKA 激活，也不会阻止 PDGF 诱导的特发性肺动脉高压 (PAH) 患者 PASMC 中丝氨酸 369 处钙蛋白酶 2 磷酸化的减少。这些数据表明，BMP4 通过 PKA 介导的抑制正常 PASMC 中的 calpain-2 来抑制 PDGF 诱导的细胞增殖和胶原蛋白合成。 BMP4 对 PDGF 诱导的细胞增殖、胶原蛋白合成和 calpain-2 激活的抑制作用在 PAH 患者的 PASMC 中受损，这可能有助于 PAH 的肺血管重塑。
In the present study, we investigated the effect of bone morphogenetic protein 4 (BMP4) on PDGF-induced cell proliferation and collagen synthesis in pulmonary artery smooth muscle cells (PASMCs). Normal human PASMCs were incubated with and without PDGF-BB in the absence and presence of BMP4 for 0.5 to 24 h. The protein levels of collagen-I, p-Smad2/3, p-Smad1/5, and intracellular active TGF- 1, calpain activity, and cell proliferation were then measured. The results showed that BMP4 induced an increase in p-Smad1/5 but had no effect on the protein levels of collagen-I, p-Smad2/3, and intracellular active TGF-beta 1 and calpain activity in control PASMCs. Nevertheless, BMP4 attenuated increases in cell proliferation and protein levels of collagen-I, p-Smad2/3, and intracellular active TGF-beta 1 and calpain activity in PASMCs exposed to PDGF-BB. Moreover, BMP4 increased PKA activity and inhibition of PKA prevented the inhibitory effects of BMP4 on PDGF-BB-induced calpain activation in normal PASMCs. The PKA activator forskolin recapitulated the suppressive effect of BMP4 on PDGF-induced calpain activation. Furthermore, BMP4 prevented a PDGF-induced decrease in calpain-2 phosphorylation at serine-369 in normal PASMCs. Finally, BMP4 did not attenuate PDGF-induced increases in cell proliferation, collagen-I protein levels, and calpain activation and did not induce PKA activation and did not prevent a PDGF-induced decrease in calpain-2 phosphorylation at serine-369 in PASMCs from idiopathic pulmonary arterial hypertension (PAH) patients. These data demonstrate that BMP4 inhibits PDGF-induced cell proliferation and collagen synthesis via PKA-mediated inhibition of calpain-2 in normal PASMCs. The inhibitory effects of BMP4 on PDGF-induced cell proliferation, collagen synthesis, and calpain-2 activation are impaired in PASMCs from PAH patients, which may contribute to pulmonary vascular remodeling in PAH.