Regulation of TGF-β1-driven Differentiation of Human Lung Fibroblasts EMERGING ROLES OF CATHEPSIN B AND CYSTATIN C
Regulation of TGF-β1-driven Differentiation of Human Lung Fibroblasts EMERGING ROLES OF CATHEPSIN B AND CYSTATIN C
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DOI：
10.1074/jbc.m113.542407
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发表时间：
2014-06-06
影响因子：
4.8
通讯作者：
Lalmanach, Gilles
中科院分区：
文献类型：
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作者：
Kasabova, Mariana;Joulin-Giet, Alix;Lalmanach, Gilles
肺基质稳态部分依赖于蛋白水解活性的精细调节。我们检测了人半胱氨酸组织蛋白酶（Cats）的表达及其对TGF-β 1诱导成纤维细胞分化为肌成纤维细胞的相对贡献。使用从特发性肺纤维化患者获得的原代成纤维细胞和人肺CCD-19 Lu成纤维细胞进行测定。Cat B的药理学抑制和遗传沉默减少了α-平滑肌肌动蛋白表达，延迟了成纤维细胞分化，并导致细胞内50-kDa TGF-β 1的积累。此外，添加Cat B在Cat B siRNA预处理的裂解物中产生25-kDa成熟形式的TGF-β 1。抑制Cat B可降低Smad 2/3的磷酸化，但对p38 MAPK和JNK的磷酸化没有影响，表明Cat B主要干扰TGF-β 1驱动的经典Smad信号通路。虽然半胱氨酸蛋白酶抑制剂C的mRNA表达是稳定的，它的分泌，这是由布雷菲德菌素A抑制，增加在TGF-β 1诱导分化的特发性肺纤维化和CCD-19 Lu成纤维细胞。此外，半胱氨酸蛋白酶抑制剂C参与了细胞外猫的控制，因为它的基因沉默恢复了它们的蛋白水解活性。这些数据支持Cat B参与肺肌纤维化的观点，如肝纤维化期间星状细胞所示。此外，我们提出，TGF-β 1通过驱动有效的胱抑素C依赖性抑制细胞外基质降解猫促进纤维化。
Lung matrix homeostasis partly depends on the fine regulation of proteolytic activities. We examined the expression of human cysteine cathepsins (Cats) and their relative contribution to TGF-beta 1-induced fibroblast differentiation into myofibroblasts. Assays were conducted using both primary fibroblasts obtained from patients with idiopathic pulmonary fibrosis and human lung CCD-19Lu fibroblasts. Pharmacological inhibition and genetic silencing of Cat B diminished alpha-smooth muscle actin expression, delayed fibroblast differentiation, and led to an accumulation of intracellular 50-kDa TGF-beta 1. Moreover, the addition of Cat B generated a 25-kDa mature form of TGF-beta 1 in Cat B siRNA-pretreated lysates. Inhibition of Cat B decreased Smad 2/3 phosphorylation but had no effect on p38 MAPK and JNK phosphorylation, indicating that Cat B mostly disturbs TGF-beta 1-driven canonical Smad signaling pathway. Although mRNA expression of cystatin C was stable, its secretion, which was inhibited by brefeldin A, increased during TGF-beta 1-induced differentiation of idiopathic pulmonary fibrosis and CCD-19Lu fibroblasts. In addition, cystatin C participated in the control of extracellular Cats, because its gene silencing restored their proteolytic activities. These data support the notion that Cat B participates in lung myofibrogenesis as suggested for stellate cells during liver fibrosis. Moreover, we propose that TGF-beta 1 promotes fibrosis by driving the effective cystatin C-dependent inhibition of extracellular matrix-degrading Cats.