Yang Yuan, Zhu Shuai, Li Yanhong, Lu Qian, Zhang Qiuyi, Su Linchong, Zhang Qiuping, Zhao Yi, Luo Yubin, Liu Yi
Department of Rheumatology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, P.R. China.
Department of Rheumatology and Immunology, The First Affiliated Hospital of Chengdu Medical College, Chengdu, Sichuan 610500, P.R. China.
Exp Ther Med. 2020 Dec;20(6):257. doi: 10.3892/etm.2020.9387. Epub 2020 Oct 27.
Mesenchymal stem cell (MSC) infusion has become a novel therapeutic strategy for complex autoimmune diseases; however, few detailed studies have been performed to investigate the benefit and mechanism of MSC treatment on systemic sclerosis (SSc). The present study aimed to evaluate the therapeutic effect of human umbilical cord derived-MSCs (UC-MSCs) on bleomycin-induced SSc in mice and explore the potential underlying mechanism. The murine SSc model was established by daily subcutaneous injection of bleomycin for 4 weeks, followed with two UC-MSC infusions every 7 days. Skin fibrosis was assessed by H&E and Masson staining. Flow cytometry was used to determine IL-17A, IFN-γ, tumor necrosis factor-β, IL-10 and IL-12 levels in serum samples and T cell subsets in murine spleen. Additionally, gene expression levels of cytokines and fibrosis markers in skin samples were measured by reverse transcription-quantitative PCR. Immunofluorescence staining was performed to track UC-MSC localization and lymphocyte cell infiltration . UC-MSC treatment exerted an anti-fibrotic role in bleomycin-induced SSc mice, as confirmed by histological improvement, decreased collagen synthesis, and reduced collagen-1α1, collagen-1α2, fibronectin-1 and α-smooth muscle actin gene expression levels. The results indicated that UC-MSC treatment only had a limited systematic effect on cytokine production in serum samples and T cell activation in the spleen. By contrast, T helper (Th)17 cell infiltration and activation in skin were efficiently inhibited after UC-MSC infusion, as evidenced by the decreased IL-17A and retinoic acid-related orphan receptor γt gene expression as well as IL-17A production. UC-MSC administration significantly ameliorated bleomycin-induced skin fibrosis and collagen formation primarily by eliminating local inflammation and Th17 cell activation in the skin; however, the systemic inhibitory effect of UM-MSCs on cytokines was less profound.
间充质干细胞（MSC）输注已成为治疗复杂自身免疫性疾病的一种新策略；然而，关于MSC治疗系统性硬化症（SSc）的益处和机制，鲜有详细研究。本研究旨在评估人脐带间充质干细胞（UC-MSC）对博来霉素诱导的小鼠SSc的治疗效果，并探索其潜在机制。通过连续4周每日皮下注射博来霉素建立小鼠SSc模型，随后每7天输注两次UC-MSC。通过苏木精-伊红（H&E）和Masson染色评估皮肤纤维化情况。采用流式细胞术检测血清样本中白细胞介素-17A（IL-17A）、干扰素-γ（IFN-γ）、肿瘤坏死因子-β、IL-10和IL-12水平以及小鼠脾脏中的T细胞亚群。此外，通过逆转录定量聚合酶链反应检测皮肤样本中细胞因子和纤维化标志物的基因表达水平。进行免疫荧光染色以追踪UC-MSC的定位和淋巴细胞浸润情况。组织学改善、胶原合成减少以及胶原-1α1、胶原-1α2、纤连蛋白-1和α-平滑肌肌动蛋白基因表达水平降低证实了UC-MSC治疗对博来霉素诱导的SSc小鼠具有抗纤维化作用。结果表明，UC-MSC治疗对血清样本中的细胞因子产生和脾脏中的T细胞活化仅具有有限的全身效应。相比之下，UC-MSC输注后皮肤中辅助性T（Th）17细胞浸润和活化受到有效抑制，IL-17A和维甲酸相关孤儿受体γt基因表达降低以及IL-17A产生减少证明了这一点。UC-MSC给药主要通过消除皮肤局部炎症和Th17细胞活化，显著改善了博来霉素诱导的皮肤纤维化和胶原形成；然而，UM-MSCs对细胞因子的全身抑制作用较弱。
