Shao Songjun, Fang Haiyan, Duan Lindi, Ye Xianwei, Rao Shanshan, Han Jin, Li Yumei, Yuan Guohang, Liu Weijia, Zhang Xiangyan
Department of Respiratory and Critical Medicine, Guizhou Provincial People's Hospital, Guiyang, China.
Academic Department, Guizhou Institute of Respiratory Diseases, Guiyang, China.
Arch Med Sci. 2019 Jan 16;16(2):436-445. doi: 10.5114/aoms.2018.81357. eCollection 2020.
Lysyl hydroxylase 3 (LH3) is a collagen post-translational modifying enzyme; it is abnormally activated during the formation of collagen cross-links. iCRT3 is an inhibitor of both Wnt and β-catenin responsive transcription. We hypothesized that LH3 is regulated by TGFβ1/Smad3 signaling and Wnt/β-catenin signaling pathways. Some evidence suggested that there is complicated cross-talk between the two signal pathways in the genesis of pulmonary fibrosis.
The normal culturing human lung cancer cell line A549 was derived from pulmonary epithelial cells. Transforming growth factor-β1 (TGF-β1) was induced A549 cells of pulmonary fibrosis. MTT assays detected cell growth stimulation by TGF-β1; collagen pyridine-crosslinking contents were detected by ELISA kits. Immunofluorescence were used to evaluate expression of key molecules in PLOD3 (LH3), Wnt/β-catenin and TGFβ1/Smad3 pathways.
Our findings suggested that iCRT3 could decrease LH3 protein expression ( < 0.01), Wnt1, β-catenin and p-Smad3 protein expression ( < 0.05). Knock-down PLOD3 could decrease LH3, collagen I gene and protein expression ( < 0.05). These effects were associated with decreasing collagen pyridine-crosslinking production ( < 0.05). However, ovexpression PLOD3 could increase LH3, collagen I gene and protein expression ( < 0.05). The result showed that LH3 plays an important role in collagen post-translational modifications, and it is regulated by Wnt/β-catenin and TGFβ1/Smad3 pathways.
This study suggests that PLOD3 (LH3) represents a target to prevent pulmonary fibrosis.
赖氨酰羟化酶3（LH3）是一种胶原蛋白翻译后修饰酶；它在胶原蛋白交联形成过程中被异常激活。iCRT3是Wnt和β-连环蛋白反应性转录的抑制剂。我们假设LH3受TGFβ1/Smad3信号通路和Wnt/β-连环蛋白信号通路调控。一些证据表明，在肺纤维化发生过程中，这两条信号通路之间存在复杂的相互作用。
正常培养的人肺癌细胞系A549源自肺上皮细胞。转化生长因子-β1（TGF-β1）诱导A549细胞发生肺纤维化。MTT法检测TGF-β1对细胞生长的刺激作用；用ELISA试剂盒检测胶原蛋白吡啶交联含量。采用免疫荧光法评估PLOD3（LH3）、Wnt/β-连环蛋白和TGFβ1/Smad3信号通路中关键分子的表达。
我们的研究结果表明，iCRT3可降低LH3蛋白表达（<0.01）、Wnt1、β-连环蛋白和p-Smad3蛋白表达（<0.05）。敲低PLOD3可降低LH3、I型胶原蛋白基因和蛋白表达（<0.05）。这些作用与胶原蛋白吡啶交联产物减少有关（<0.05）。然而，过表达PLOD3可增加LH3、I型胶原蛋白基因和蛋白表达（<0.05）。结果表明，LH3在胶原蛋白翻译后修饰中起重要作用，且受Wnt/β-连环蛋白和TGFβ1/Smad3信号通路调控。
本研究表明，PLOD3（LH3）是预防肺纤维化的一个靶点。
