Biopharmaceutical Key Laboratory of Heilongjiang Province, College of Pharmacy, Harbin Medical University, Harbin, Heilongjiang Province 150081, P.R. China.
College of Pharmacy, Harbin University of Commerce, Harbin, Heilongjiang Province 150081, P.R. China.
Mol Ther. 2021 Apr 7;29(4):1411-1424. doi: 10.1016/j.ymthe.2021.01.005. Epub 2021 Jan 9.
Pulmonary artery smooth muscle cells (PASMCs) proliferation caused by hypoxia is an important pathological process of pulmonary hypertension (PH). Prevention of PASMCs proliferation can effectively reduce PH mortality. Long non-coding RNAs (lncRNAs) are involved in the proliferation process. Recent evidence has demonstrated that functional peptides encoded by lncRNAs play important roles in cell pathophysiological process. Our previous study has demonstrated that lnc-Rps4l with high coding ability mediates the PASMCs proliferation under hypoxic conditions. We hypothesize in this study that a lnc-Rps4l-encoded peptide is involved in hypoxic-induced PASMCs proliferation. The presence of peptide 40S ribosomal protein S4 X isoform-like (RPS4XL) encoded by lnc-Rps4l in PASMCs under hypoxic conditions was confirmed by bioinformatics, immunofluorescence, and immunohistochemistry. Inhibition of proliferation by the peptide RPS4XL was demonstrated in hypoxic PASMCs by MTT, bromodeoxyuridine (BrdU) incorporation, and immunofluorescence assays. By using the bioinformatics, coimmunoprecipitation (coIP), and mass spectrometry, RPS6 was identified to interact with RPS4XL. Furthermore, lnc-Rps4l-encoded peptide RPS4XL inhibited the RPS6 process via binding to RPS6 and inhibiting RPS6 phosphorylation at p-RPS6 (Ser240+Ser244) phosphorylation site. These results systematically elucidate the role and regulatory network of Rps4l-encoded peptide RPS4XL in PASMCs proliferation. These discoveries provide potential targets for early diagnosis and a leading compound for treatment of hypoxic PH.
缺氧引起的肺动脉平滑肌细胞（PASMC）增殖是肺动脉高压（PH）的重要病理过程。预防 PASMC 增殖可以有效降低 PH 死亡率。长链非编码 RNA（lncRNA）参与细胞增殖过程。最近的证据表明，lncRNA 编码的功能肽在细胞病理生理过程中发挥重要作用。我们之前的研究表明，具有高编码能力的 lnc-Rps4l 介导缺氧条件下 PASMC 的增殖。在这项研究中，我们假设 lnc-Rps4l 编码的肽参与缺氧诱导的 PASMC 增殖。通过生物信息学、免疫荧光和免疫组织化学证实了在缺氧条件下 lnc-Rps4l 在 PASMCs 中存在编码肽 40S 核糖体蛋白 S4 X 同工型（RPS4XL）。通过 MTT、溴脱氧尿苷（BrdU）掺入和免疫荧光测定证实了肽 RPS4XL 在缺氧 PASMCs 中的增殖抑制作用。通过生物信息学、共免疫沉淀（coIP）和质谱分析，鉴定出 RPS6 与 RPS4XL 相互作用。此外，lnc-Rps4l 编码肽 RPS4XL 通过与 RPS6 结合并抑制 RPS6 在 p-RPS6（Ser240+Ser244）磷酸化位点的磷酸化来抑制 RPS6 过程。这些结果系统地阐明了 Rps4l 编码肽 RPS4XL 在 PASMC 增殖中的作用和调节网络。这些发现为早期诊断提供了潜在的靶点，并为治疗缺氧 PH 提供了先导化合物。
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