Promotion of Myofibroblast Differentiation and Tissue Fibrosis by the Leukotriene B4-Leukotriene B4 Receptor Axis in Systemic Sclerosis
Promotion of Myofibroblast Differentiation and Tissue Fibrosis by the Leukotriene B4-Leukotriene B4 Receptor Axis in Systemic Sclerosis
复制标题
DOI：
10.1002/art.41192
复制
发表时间：
2020-04-30
影响因子：
13.3
通讯作者：
Zou, Hejian
中科院分区：
文献类型：
--
作者：
Liang, Minrui;Lv, Jiaoyan;Zou, Hejian
目的探讨炎性脂质介质白三烯B-4(LTB4)及其受体BLT1在系统性硬化症(SSC)发生发展中的作用。对SSC患者和健康人的皮肤和肺组织切片进行白三烯A(4)水解酶(LTA(4)H)和BLT1的免疫组织化学染色，结合不同的细胞标志物。在博莱霉素或血管紧张素II攻击或DNA拓扑异构酶I免疫的SSc小鼠模型中，通过遗传或药物阻断LTB4-BLT1轴，以评估其对全身疾病特征和肌成纤维细胞标志物的影响。结果SSc患者血清LTb4水平较正常对照组升高44.93%(平均+/-SD 220.3+/-74.75pg/mlvs 152.0+/-68.05pg/ml；P<；0.0001)，并与SSc相关性间质性肺疾病和弥漫性皮肤SSc相关。SSC患者皮损部位LTA(4)H和BLT1水平升高，且均大量表达于肌成纤维细胞和内皮细胞。阻断SSC小鼠模型的LTB4-BLT1轴可显著减轻皮肤和肺纤维化，博莱霉素组小鼠皮肤和肺组织中α-平滑肌肌动蛋白阳性的肌成纤维细胞分别减少54.00%和52.65%。重组LTB4刺激的成纤维细胞、内皮细胞和SSC患者血清的免疫印迹结果显示，BLT1促进了成纤维细胞-肌成纤维细胞和内皮-间充质细胞的转化，这依赖于磷脂酰肌醇3-激酶(PI3K)/Akt/雷帕霉素机械靶(MTOR)途径的激活，而不依赖于成纤维细胞或内皮细胞释放转化生长因子β(TGFβ)。结论LTB4-BLT1轴可能通过PI3K/Akt/mTOR途径直接促进成肌细胞分化而参与SSC纤维化的发生，这一过程似乎不依赖于转化生长因子的自分泌。
Objective To investigate the role of the inflammatory lipid mediator leukotriene B-4 (LTB4) and its receptor, BLT1, in the development and progression of systemic sclerosis (SSc).Methods Serum levels of LTB4 were compared in 64 patients with SSc and 80 healthy controls. Skin and lung tissue sections from patients with SSc and healthy donors were immunostained for leukotriene A(4) hydrolase (LTA(4)H), the critical enzyme for LTB4 synthesis, and BLT1, in combination with different cell markers. In mouse models of SSc using bleomycin or angiotensin II challenge or immunization with the DNA topoisomerase I, genetic or pharmacologic interruption of the LTB4-BLT1 axis in mice was carried out to assess its effects on systemic disease features and myofibroblast markers. Immunoblotting was performed to examine the signaling pathway in fibroblasts and endothelial cells following stimulation with LTB4 or with serum from SSc patients.Results Serum LTB4 levels were 44.93% higher in patients with SSc than in matched healthy controls (mean +/- SD 220.3 +/- 74.75 pg/ml versus 152.0 +/- 68.05 pg/ml; P < 0.0001), and this was associated with the patient subsets of SSc-associated interstitial lung disease and diffuse cutaneous SSc. Levels of LTA(4)H and BLT1 were increased in lesional areas of the skin and lungs of SSc patients, and both were abundant in myofibroblasts and endothelial cells. Interruption of the LTB4-BLT1 axis in mouse models of SSc significantly mitigated dermal and pulmonary fibrosis, with 54.00% and 52.65% fewer alpha-smooth muscle actin-positive myofibroblasts accumulating in the skin and lungs of mice, respectively, after bleomycin challenge. Immunoblotting of cultures with recombinant LTB4-stimulated fibroblasts and endothelial cells or with serum from SSc patients showed that fibroblast-myofibroblast and endothelial-mesenchymal transitions were promoted via BLT1, and that this was dependent on activation of the phosphatidylinositol 3-kinase (PI3K)/Akt/mechanistic target of rapamycin (mTOR) pathway but independent of the release of transforming growth factor beta (TGF beta) by fibroblasts or endothelial cells.Conclusion The LTB4-BLT1 axis may contribute to fibrosis in SSc by directly promoting myofibroblast differentiation via the PI3K/Akt/mTOR pathway, and this appears to operate independently of autocrine secretion of TGF beta.