Jafarinejad-Farsangi Saeideh, Farazmand Ali, Mahmoudi Mahdi, Gharibdoost Farhad, Karimizadeh Elham, Noorbakhsh Farshid, Faridani Habibeh, Jamshidi Ahmad Reza
a Department of Cell and Molecular Biology , University of Tehran , Tehran , Iran .
Autoimmunity. 2015;48(6):369-78. doi: 10.3109/08916934.2015.1030616. Epub 2015 Apr 10.
The most prominent feature of systemic sclerosis (SSc) and other diseases associated with fibrosis is the prolonged activation of fibroblasts not eliminated by apoptosis, hence characterized by accumulation of more extra cellular matrix (ECM). We tend to verify if microRNA-29a (miR-29a) as an anti-fibrotic factor could induce apoptosis in SSc fibroblasts. We did not detect apoptosis in SSc fibroblasts. We found that Bcl-2 expression was upregulated in SSc fibroblasts and the ratio of Bax:Bcl-2 in these cells was significantly lower (p = 0.02) compared to normal fibroblasts. Transfection of both SSc and transforming growth factor-β (TGF-β) stimulated fibroblasts by miR-29a mimic, significantly decreased the expression of two anti-apoptotic members of the Bcl-2 family, Bcl-2 (p = 0.0005, p = 0.01) and Bcl-XL (p = 0.0001, p = 0.006), resulted in enhanced Bax:Bcl-2 ratio and induced a high rate of apoptosis. Recently, miR-29 has been introduced as an anti-fibrotic factor with potential therapeutic effect on SSc. Until now, it has not been proposed whether there is a relationship between miR-29a and apoptosis in SSc. According to our results, it seems that miR-29a is a potent inducer of apoptosis in SSc fibroblasts and an attenuator of ECM production in these cells. MiR-29a disrupted the expression profiling of Bcl-2 family proteins (Bax, Bcl-2 and Bcl-XL) which is the central point of dynamic life-death rheostat in many apoptotic pathways. Furthermore, dermal fibroblasts from patients with SSc showed elevation in TNF-α mRNA levels, while restoration of miR-29a decreases TNF-α production in these cells. Although further molecular studies are necessary to investigate the underlying apoptotic pathways, the present findings suggest that anti-fibrotic and pro-apoptotic properties of miR-29a could provide novel benefits toward the development of fibroblast-specific anti-fibrotic therapies.
系统性硬化症（SSc）及其他与纤维化相关疾病最显著的特征是成纤维细胞长时间激活，未因凋亡而被清除，因此其特征为细胞外基质（ECM）积累增多。我们试图验证作为抗纤维化因子的微小RNA-29a（miR-29a）是否能诱导SSc成纤维细胞凋亡。我们未在SSc成纤维细胞中检测到凋亡。我们发现SSc成纤维细胞中Bcl-2表达上调，与正常成纤维细胞相比，这些细胞中Bax:Bcl-2的比例显著降低（p = 0.02）。用miR-29a模拟物转染SSc和转化生长因子-β（TGF-β）刺激的成纤维细胞，显著降低了Bcl-2家族两个抗凋亡成员Bcl-2（p = 0.0005，p = 0.01）和Bcl-XL（p = 0.0001，p = 0.006）的表达，导致Bax:Bcl-2比例升高并诱导了高凋亡率。最近，miR-29已被作为一种对SSc有潜在治疗作用的抗纤维化因子引入。到目前为止，尚未有人提出miR-29a与SSc中的凋亡之间是否存在关联。根据我们的结果，似乎miR-29a是SSc成纤维细胞凋亡的有效诱导剂，也是这些细胞中ECM产生的减弱剂。miR-29a破坏了Bcl-2家族蛋白（Bax、Bcl-2和Bcl-XL）的表达谱，而这是许多凋亡途径中动态生死调节的关键点。此外，SSc患者的真皮成纤维细胞显示肿瘤坏死因子-α（TNF-α）mRNA水平升高，而miR-29a的恢复降低了这些细胞中TNF-α的产生。尽管需要进一步的分子研究来探究潜在的凋亡途径，但目前的研究结果表明，miR-29a的抗纤维化和促凋亡特性可为成纤维细胞特异性抗纤维化疗法的开发提供新的益处。
