Previous studies have shown that some specific long non-coding RNAs are dysregulated in vascular walls and abnormally expressed in vascular disease. LncRNA HLA complex group 18 (HCG18) is a member of the HLA complex group, which has been rarely investigated in human diseases. In this study, we aimed to investigate the role of HCG in vascular smooth muscle cells. HCG18 was over-expressed by adenovirus transfection and knocked down in vascular smooth muscle cells by shRNA. Cell proliferation was detected by CCK-8 assays. Flow cytometry was employed to test the impacts of HCG18 on vascular smooth muscle apoptotic cells. The expression of associated genes in protein and mRNA levels was detected by western blotting, immunofluorescence and qRT-PCR. The interactions between HCG18 and fused in sarcoma (FUS) were confirmed by RNA EMSA and RIP assays. The expression of serum HCG18 was decreased in hypertensive patients and PDGF-BB-treated vascular smooth muscle cells. HCG18 inhibited proliferation and induced apoptotic cells in vascular smooth muscle cells. In addition, we also found that HCG18 can inhibit vascular smooth muscle cell phenotypic switching from a contractile to a secretory phenotype. Finally, our results showed that HCG18 enhanced apoptotic cells by directly binding with FUS. Our findings reveal that HCG18 is involved in the regulation of proliferation, apoptosis and the expression levels of markers of the contractile and synthetic phenotype.

中文翻译：

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LncRNA HCG18对于血管平滑肌细胞增殖和表型转换至关重要。

先前的研究表明，某些特定的长非编码RNA在血管壁中失调，在血管疾病中异常表达。LncRNA HLA复合物组18（HCG18）是HLA复合物组的成员，很少在人类疾病中进行研究。在这项研究中，我们旨在研究HCG在血管平滑肌细胞中的作用。HCG18在腺病毒转染中过表达，并在shRNA中在血管平滑肌细胞中被敲低。通过CCK-8测定法检测细胞增殖。流式细胞仪用于测试HCG18对血管平滑肌凋亡细胞的影响。通过蛋白质印迹，免疫荧光和qRT-PCR检测蛋白质和mRNA水平中相关基因的表达。RNA EMSA和RIP分析证实了HCG18与肉瘤融合症（FUS）之间的相互作用。高血压患者和PDGF-BB治疗的血管平滑肌细胞中血清HCG18的表达降低。HCG18抑制增生并诱导血管平滑肌细胞凋亡。此外，我们还发现HCG18可以抑制血管平滑肌细胞表型从收缩型转变为分泌型。最后，我们的结果表明，HCG18通过直接与FUS结合来增强凋亡细胞。我们的研究结果表明，HCG18参与调节增殖，凋亡和收缩和合成表型标志物的表达水平。我们还发现，HCG18可以抑制血管平滑肌细胞表型从收缩型转变为分泌型。最后，我们的结果表明，HCG18通过直接与FUS结合来增强凋亡细胞。我们的发现表明，HCG18参与了增殖，凋亡和可收缩和合成表型标志物表达水平的调节。我们还发现，HCG18可以抑制血管平滑肌细胞表型从收缩型转变为分泌型。最后，我们的结果表明，HCG18通过直接与FUS结合来增强凋亡细胞。我们的发现表明，HCG18参与了增殖，凋亡和可收缩和合成表型标志物表达水平的调节。