Research of heat shock protein 47 and defensins in the pathogenesis of pulmonary fibrosis

热休克蛋白(HSP)47作为胶原特异性分子伴侣参与了多种胶原蛋白的合成和组装。HSP47在肝硬变和其他纤维化疾病中的表达上调。本文研究了中性粒细胞天青颗粒中具有抗菌和细胞毒活性的阳离子蛋白α防御素对肺成纤维细胞产生热休克蛋白47和胶原的影响，以及热休克蛋白47的表达与肺纤维化过程的关系。首先，利用手术活检标本，我们发现特发性普通型间质性肺炎(UIP)患者肺成纤维细胞和II型肺泡细胞中HSP47的表达明显高于胶原血管病相关的UIP和特发性非特异性间质性肺炎，与特发性UIP相比预后更好。我们还研究了α-Defen…的直接作用人中性粒细胞多肽(HNP-1)对人肺成纤维细胞HSP47和胶原-1表达的影响5μg/mlHNP-1诱导成纤维细胞增殖，50μg/mlHNP-1使成纤维细胞活力下降。当HNP-1浓度为10~25μg/ml时，HSP47和胶原-1mRNA的表达显著增加，蛋白释放量呈剂量依赖性增加。转化生长因子-β也促进了人正常成纤维细胞和A549细胞中这些mRNA和蛋白的表达，而吡非尼酮抑制了这些发现。此外，我们还利用实时荧光定量聚合酶链式反应技术研究了转化生长因子β对A549细胞和成纤维细胞中PDGF和HGF等生长因子表达的影响。在博莱霉素诱导的小鼠肺纤维化模型中，HSP47的表达与肺纤维化的程度也有很好的相关性。提示α-防御素可能通过上调HSP47和胶原-1的表达，直接促进肺成纤维细胞的纤维化进程，在肺纤维化的发病机制中起重要作用，HSP47阳性细胞可能具有促进胶原合成和释放的能力。吡非尼酮直接抑制这些阳性细胞，这些阳性细胞负责肺纤维化中细胞外基质的积累和沉积。这些发现提示BSP47和α-防御素可能是治疗特发性肺纤维化的新的有希望的靶点。较少

Heat shock Protein (HSP) 47 is involved in the synthesis/assembly of various collagens as a collagen-Specific molecular chaperone. HSP 47 expression has been shown upregulated in liver cirrhosis and other fibrotic diseases. We have studied the effect of α-defensin, cationic proteins with antimicrobial and cytotoxic activity in the azurophil granule of neutrophils, on the production of HSP 47 and collagen using lung fibroblasts, and the relationship between HSP47 expression and fibrotic process in murine bleomycin-induced pulmonary fibrosis. At first, using surgical biopsy specimens from human patients, we demonstrated that expression of HSP47 in lung fibroblasts and type II pneumocytes was significantly higher in idiopathic usual interstitial pneumonia (UIP) patients than in those with collagen vascular disease-associated UIP and idiopathic non-specific interstitial pneumonia, which has the better prognosis compared with idiopathic UIP. We also investigated the direct effect of α-defen … More sin (human neutrophil peptide (HNP)-1) on expression of HSP47 and collagen-1 in human lung fibroblasts. HNP-1 5 μg/ml induced fibroblast proliferatioh and concentrations >50 μg/ml of HNP-1 reduced the cell-viability. Expression of HSP 47 and collagen-1 mRNA was significantly increased by 10 to 25 μg/ml of HNP-1, whereas their protein release increased in dose-dependent manner. TGF-beta also enhanced the expression of these mRNA and proteins in human normal fibroblasts and A549 cells, and pirfenidone inhibited these findings. In addition, We are studying the effects of TGF-beta on expression of growth factors including PDGF and HGF in A549 and fibroblasts using real time PCR. In murine bleomycin-induced pulmonary fibrosis, a good correlation was also observed between the degree of pulmonary fibrosis and expression of HSP47 using in situ hybridization. Our results suggest that α-defensin may promote directly fibrotic process through upregulation of HSP 47 and collagen-1 in human lung fibroblasts and play an important role in the pathogenesis of pulmonary fibrosis and HSP47 positive cells may have an ability of enhanced collagen synthesis and release. Pirfenidone inhibited directly these positive cells responsible for the accumulation and deposition of extracellular matrix seen in pulmonary fibrosis. These findings suggest that BSP47 and α-defensin might be anew promising target for the treatment of idiopathic pulmonary fibrosis. Less