Significant role of long non-coding RNA MALAT1 in deep vein thrombosis via the regulation of vascular endothelial cell physiology through the microRNA-383-5p/BCL2L11 axis

Deep vein thrombosis (DVT) is a vascular disease. The long non-coding RNA (lncRNA), metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), is positively expressed in DVT tissues, and regulates the biological behavior of endothelial progenitor cells. Here, we explored whether MALAT1 affected the physiology of human vascular endothelial cells (HUVECs) and analyzed its underlying mechanism. To overexpress/silence the expression of MALAT1 in HUVECs, MALAT1-plasmid/MALAT1-small interfering RNA (siRNA) was used. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and flow cytometry analyses were performed to observe the cell viability and apoptosis. Reverse transcription-quantitative polymerase chain reaction and western blotting were used to determine the apoptosis-related protein and gene expression levels. We used Starbase software to predict the associations among MALAT1, microRNA (miR)-383-5p, and BCL2-like 11 (BCL2L11). Luciferase reporter assay was used to validate their relationship. Compared to the control vector group, MALAT1-plasmid suppressed the viability and induced apoptosis of HUVECs, while improving Bcl-2-associated X protein (Bax) expression and decreasing Bcl-2 expression. There was an interaction between MALAT1 and miR-383-5p. Compared to the control siRNA group, MALAT1-siRNA increased the cell viability, reduced cell apoptosis, upregulated Bcl-2 expression, and suppressed Bax expression. These changes were reversed by the miR-383-5p inhibitor. Additionally, we verified that BCL2L11 is a target of miR-383-5p. miR-383-5p improved the cell proliferation, while decreasing cell apoptosis in HUVECs by targeting BCL2L11. Therefore, the lncRNA-MALAT1/miR-383-5p/BCL2L11 axis may be effective for DVT treatment.

深静脉血栓形成（deep vein thrombosis, DVT）是一类血管疾病。长链非编码RNA（long non-coding RNA, lncRNA）转移相关肺腺癌转录本1（metastasis-associated lung adenocarcinoma transcript 1, MALAT1）在DVT组织中呈阳性表达，且可调控内皮祖细胞的生物学行为。本研究旨在探讨MALAT1对人脐静脉内皮细胞（human vascular endothelial cells, HUVECs）生理功能的影响，并解析其潜在作用机制。为在HUVECs中过表达或沉默MALAT1的表达，本研究采用MALAT1过表达质粒（MALAT1-plasmid）与MALAT1小干扰RNA（small interfering RNA, siRNA）进行干预。通过噻唑蓝[3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐，MTT]法与流式细胞术检测细胞活力与细胞凋亡情况；采用逆转录定量聚合酶链反应（reverse transcription-quantitative polymerase chain reaction, RT-qPCR）与蛋白质印迹法检测凋亡相关蛋白及基因的表达水平。本研究借助Starbase软件预测MALAT1、微小RNA（microRNA, miR）-383-5p与BCL2样蛋白11（BCL2-like 11, BCL2L11）三者间的靶向关联，并通过双荧光素酶报告基因实验验证其调控关系。实验结果显示：与空载体对照组相比，MALAT1过表达质粒可抑制HUVECs的细胞活力并诱导细胞凋亡，同时上调Bcl-2相关X蛋白（Bcl-2-associated X protein, Bax）的表达，下调Bcl-2的表达；且MALAT1与miR-383-5p之间存在靶向结合作用。与阴性对照siRNA组相比，MALAT1小干扰RNA可提升HUVECs的细胞活力、降低细胞凋亡率，同时上调Bcl-2的表达并抑制Bax的表达，而miR-383-5p抑制剂可逆转上述效应。此外，本研究证实BCL2L11是miR-383-5p的下游靶基因；miR-383-5p可通过靶向调控BCL2L11的表达，促进HUVECs的增殖并抑制其凋亡。综上，长链非编码RNA MALAT1/miR-383-5p/BCL2L11调控轴有望成为DVT治疗的潜在靶点与策略。