Department of Pharmacy, Affiliated Zhongshan Hospital of Dalian University, Dalian, China.
Department of Radiology, Affiliated Zhongshan Hospital of Dalian University, Dalian, China.
Biochem Biophys Res Commun. 2014 Oct 3;452(4):951-7. doi: 10.1016/j.bbrc.2014.09.025. Epub 2014 Sep 16.
Acute lung injury (ALI) is a severe clinical condition with high morbidity and mortality. Apoptosis is a key pathologic feature of ALI, and Bcl-2 plays an important role during the pathogenesis of ALI via the regulation of apoptosis. However, the regulation of Bcl-2 during ALI, particularly through microRNAs, remains unclear. We hypothesize that certain miRNAs may play deleterious or protective roles in ALI via the regulation of Bcl-2. The LPS stimulation of A549 cells was used to mimic ALI in vitro. First, we confirmed that Bcl-2 is involved in LPS-induced apoptosis in A549 cells. Then, bioinformatic analyses and quantitative real-time polymerase chain reaction assays were performed to screen for miRNAs targeting Bcl-2. We observed that miR-135a was markedly increased in LPS-challenged A549 cells. miR-135a inhibition markedly restored Bcl-2 expression and protected A549 cells from LPS-induced apoptosis. Furthermore, bioinformatic analysis and luciferase activity assays were conducted to confirm that miR-135a binds directly to the 3'-untranslated region of Bcl-2 and suppresses its expression. Interestingly, the inhibition of miR-135a did not attenuate apoptosis under LPS-treated conditions when Bcl-2 was knocked down. Therefore, we suggest that miR-135a regulation of LPS-induced apoptosis in A549 cells may depend in part on the regulation of Bcl-2. The miR-135a/Bcl-2 signaling pathway may be a novel therapeutic target for the prevention of ALI.
急性肺损伤（ALI）是一种严重的临床病症，具有高发病率和死亡率。细胞凋亡是 ALI 的一个关键病理特征，Bcl-2 通过调节细胞凋亡在 ALI 的发病机制中发挥重要作用。然而，Bcl-2 在 ALI 中的调节，特别是通过 microRNAs 的调节，尚不清楚。我们假设某些 microRNAs 可能通过调节 Bcl-2 在 ALI 中发挥有害或保护作用。通过 LPS 刺激 A549 细胞来模拟体外的 ALI。首先，我们证实 Bcl-2 参与了 LPS 诱导的 A549 细胞凋亡。然后，进行了生物信息学分析和实时定量聚合酶链反应（PCR）检测，以筛选针对 Bcl-2 的 microRNAs。我们观察到，miR-135a 在 LPS 刺激的 A549 细胞中明显增加。miR-135a 抑制显著恢复了 Bcl-2 的表达，并保护 A549 细胞免受 LPS 诱导的凋亡。此外，进行了生物信息学分析和荧光素酶活性检测，以确认 miR-135a 直接结合到 Bcl-2 的 3'非翻译区并抑制其表达。有趣的是，当 Bcl-2 被敲低时，miR-135a 抑制并没有减弱 LPS 处理条件下的细胞凋亡。因此，我们认为 miR-135a 调节 LPS 诱导的 A549 细胞凋亡可能部分依赖于 Bcl-2 的调节。miR-135a/Bcl-2 信号通路可能是预防 ALI 的新的治疗靶点。
