核受体组成型雄烷受体/NR1I3 增强转化生长因子 β 的促纤维化作用，并有助于实验性皮肤纤维化的发展。

The nuclear receptor constitutive androstane receptor/NR1I3 enhances the profibrotic effects of transforming growth factor β and contributes to the development of experimental dermal fibrosis.

机构信息

University of Erlangen-Nuremberg, Erlangen, Germany; Paris Descartes University, INSERM U1016, and Cochin Hospital, AP-HP, Paris, France.

出版信息

Arthritis Rheumatol. 2014 Nov;66(11):3140-50. doi: 10.1002/art.38819.

DOI:10.1002/art.38819

PMID:25155144

Abstract

OBJECTIVE

Nuclear receptors regulate cell growth, differentiation, and homeostasis. Selective nuclear receptors promote fibroblast activation, which leads to tissue fibrosis, the hallmark of systemic sclerosis (SSc). This study was undertaken to investigate the effects of constitutive androstane receptor (CAR)/NR1I3, an orphan nuclear receptor, on fibroblast activation and experimental dermal fibrosis.

METHODS

CAR expression was quantified by quantitative polymerase chain reaction, Western blotting, immunohistochemistry, and immunofluorescence. CAR expression was modulated by small molecules, small interfering RNA, forced overexpression, and site-directed mutagenesis. The effects of CAR activation were analyzed in cultured fibroblasts, in bleomycin-induced dermal fibrosis, and in mice overexpressing a constitutively active transforming growth factor β (TGFβ) receptor type I (TβRI-CA).

RESULTS

Up-regulation of CAR was detected in the skin and in dermal fibroblasts in SSc patients. Stimulation of healthy fibroblasts with TGFβ induced the expression of CAR messenger RNA and protein in a Smad-dependent manner. Pharmacologic activation or overexpression of CAR in healthy fibroblasts significantly increased the stimulatory effects of TGFβ on collagen synthesis and myofibroblast differentiation, and amplified the stimulatory effects of TGFβ on COL1A2 transcription activity. Treatment with CAR agonist increased the activation of canonical TGFβ signaling in murine models of SSc and exacerbated bleomycin-induced and TβRI-CA-induced fibrosis with increased dermal thickening, myofibroblast counts, and collagen accumulation.

CONCLUSION

Our findings indicate that CAR is up-regulated in SSc and regulates TGFβ signaling. Activation of CAR increases the profibrotic effects of TGFβ in cultured fibroblasts and in different preclinical models of SSc. Thus, inactivation of CAR might be a novel approach to target aberrant TGFβ signaling in SSc and in other fibrotic diseases.

摘要

目的

核受体调节细胞生长、分化和内稳态。选择性核受体促进成纤维细胞活化，导致组织纤维化，这是系统性硬化症（SSc）的标志。本研究旨在探讨组成型雄烷受体（CAR）/NR1I3（一种孤儿核受体）对成纤维细胞活化和实验性皮肤纤维化的影响。

方法

通过定量聚合酶链反应、Western 印迹、免疫组织化学和免疫荧光定量检测 CAR 表达。通过小分子、小干扰 RNA、强制过表达和定点突变调节 CAR 表达。在培养的成纤维细胞、博来霉素诱导的皮肤纤维化和过表达组成型激活转化生长因子β（TGFβ）受体 I 型（TβRI-CA）的小鼠中分析 CAR 激活的影响。

结果

在 SSc 患者的皮肤和真皮成纤维细胞中检测到 CAR 的上调。TGFβ刺激健康成纤维细胞以 Smad 依赖性方式诱导 CAR 信使 RNA 和蛋白的表达。在健康成纤维细胞中，CAR 的药理学激活或过表达显著增加了 TGFβ对胶原合成和肌成纤维细胞分化的刺激作用，并放大了 TGFβ对 COL1A2 转录活性的刺激作用。CAR 激动剂治疗增加了 SSc 小鼠模型中经典 TGFβ 信号的激活，并加剧了博来霉素诱导和 TβRI-CA 诱导的纤维化，导致皮肤增厚、肌成纤维细胞计数和胶原积累增加。