Arthritis Center, Rheumatology, Boston University School of Medicine, Boston, MA 02118, USA.
Int J Mol Med. 2012 Dec;30(6):1473-80. doi: 10.3892/ijmm.2012.1150. Epub 2012 Oct 5.
Systemic sclerosis (SSc) is characterized by fibrosis of the skin and internal organs. The present study was undertaken to examine the effects of ciprofloxacin, a fluoroquinolone antibiotic implicated in matrix remodeling, on dermal and lung fibroblasts obtained from SSc patients. Dermal and lung fibroblasts from SSc patients and healthy subjects were treated with ciprofloxacin. Western blotting was used to analyze protein levels and RT-PCR was used to measure mRNA expression. The pharmacologic inhibitor UO126 was used to block Erk1/2 signaling. SSc dermal fibroblasts demonstrated a significant decrease in collagen type I mRNA and protein levels after antibiotic treatment, while healthy dermal fibroblasts were less sensitive to ciprofloxacin, downregulating collagen only at the protein levels. Connective tissue growth factor (CCN2) gene expression was significantly reduced and matrix metalloproteinase 1 (MMP1) levels were enhanced after ciprofloxacin treatment to a similar extent in healthy and SSc fibroblasts. Ciprofloxacin induced Erk1/2 phosphorylation, and Erk1/2 blockade completely prevented MMP1 upregulation. However, Smad1 and Smad3 activation in response to TGFβ was not affected. The expression of friend leukemia integration factor 1 (Fli1), a transcriptional repressor of collagen, was increased after treatment with ciprofloxacin only in SSc fibroblasts, and this was accompanied by a decrease in the levels of DNA methyltransferase 1 (Dnmt1). Similar effects were observed in SSc-interstitial lung disease (ILD) lung fibroblasts. In summary, our study demonstrates that ciprofloxacin has antifibrotic actions in SSc dermal and lung fibroblasts via the downregulation of Dnmt1, the upregulation of Fli1 and induction of MMP1 gene expression via an Erk1/2-dependent mechanism. Thus, our data suggest that ciprofloxacin may be an attractive therapy for SSc skin and lung fibrosis.
系统性硬化症（SSc）的特征是皮肤和内脏器官纤维化。本研究旨在探讨氟喹诺酮类抗生素环丙沙星对来自 SSc 患者的皮肤和肺成纤维细胞的影响，该抗生素与基质重塑有关。用环丙沙星处理 SSc 患者和健康受试者的皮肤和肺成纤维细胞。采用 Western blot 分析蛋白水平，采用 RT-PCR 测量 mRNA 表达。用药理抑制剂 UO126 阻断 Erk1/2 信号。抗生素治疗后，SSc 皮肤成纤维细胞的 I 型胶原 mRNA 和蛋白水平显著降低，而健康皮肤成纤维细胞对环丙沙星的敏感性较低，仅在蛋白水平下调胶原。结缔组织生长因子（CCN2）基因表达在抗生素处理后显著降低，基质金属蛋白酶 1（MMP1）水平在健康和 SSc 成纤维细胞中均显著升高。环丙沙星诱导 Erk1/2 磷酸化，Erk1/2 阻断完全阻止了 MMP1 的上调。然而，TGFβ 刺激下 Smad1 和 Smad3 的激活不受影响。仅在 SSc 成纤维细胞中，环丙沙星处理后朋友白血病整合因子 1（Fli1）的表达增加，这伴随着 DNA 甲基转移酶 1（Dnmt1）水平的降低。在 SSc 间质性肺疾病（ILD）肺成纤维细胞中也观察到类似的作用。总之，我们的研究表明，环丙沙星通过下调 Dnmt1、上调 Fli1 和诱导 MMP1 基因表达，在 SSc 皮肤和肺成纤维细胞中具有抗纤维化作用，这是通过 Erk1/2 依赖的机制实现的。因此，我们的数据表明，环丙沙星可能是治疗 SSc 皮肤和肺纤维化的一种有吸引力的治疗方法。
