目的：探讨lncRNA MALAT1对视网膜血管内皮细胞增殖、迁移及血管生成的影响及其分子机制。

方法：qPCR检测正常对照组、糖尿病患者无视网膜病变组、糖尿病视网膜病变患者组血清中lncRNA MALAT1的表达水平以及葡萄糖培养对lncRNA MALAT1的表达水平的影响。qRT-PCR检测miR-124-3p表达水平； Western blotting检测SOX7表达水平； 双荧光素酶报告系统检测lncRNA MALAT1与miR-124-3p、miR-124-3p与SOX7的靶向作用关系； CCK-8实验检测细胞的增殖活力； Transwell实验检测细胞的迁移能力； 体外成管实验检测hRMECs血管形成能力。

结果：lncRNA MALAT1在糖尿病视网膜病变患者血清中的表达水平显著高于糖尿病患者无视网膜病变组和正常对照组(P<0.001)； 体外葡萄糖培养显著促进lncRNA MALAT1在hRMECs细胞的表达，并显著促进hRMECs细胞的增殖、迁移和血管形成(均P<0.05)。敲低lncRNA MALAT1显著抑制hRMECs细胞的增殖、迁移和成管能力(均P<0.05)。双荧光素酶报告基因实验表明，lncRNA MALAT1与miR-124-3p、miR-124-3p与SOX7之间存在靶向结合作用。过表达miR-124-3p显著抑制hRMECs细胞的增殖、迁移和成管能力(均P<0.05)； 过表达lncRNA MALAT1+miR-124-3p，同时过表达miR-124-3p+SOX7，敲低lncRNA MALAT1+过表达SOX7均显著消除了过表达miR-124-3p对hRMECs细胞增殖、迁移和血管形成的抑制作用(均P<0.05)。

结论：lncRNA MALAT1通过下调miR-124-3p对SOX7的负调控作用促进糖尿病视网膜病变中视网膜内皮细胞增殖、迁移和血管形成。lncRNA MALAT1在糖尿病视网膜病变患者的异常上调可能是微血管功能障碍的潜在生物标志。

METHODS: The expression levels of lncRNA MALAT1 in plasma of normal control group, diabetic without retinopathy group and diabetic retinopathy group were detected by qPCR and the effect of glucose culture on the expression levels of lncRNA MALAT1 were detected by qPCR too. The expression level of miR-124-3p was detected by qRT-PCR; Western blotting was used to detect the expression level of SOX7; The targeting relationship between lncRNA MALAT1 and miR-124-3p, miR-124-3p and SOX7 were detected by the dual-luciferase reporter system; CCK-8 assay was used to detect cell proliferation activity; Transwell assay was used to detect the migration ability of cells; Angiogenesis of hRMECs cells was measured by in vitro tube formation assay.

RESULTS:The expression level of lncRNA MALAT1 in plasma of diabetic retinopathy patients was significantly higher than that of diabetic without retinopathy group and normal control group(P<0.001). In vitro glucose culture significantly promoted the expression of lncRNA MALAT1 in hRMECs cells, as well as the proliferation, migration and angiogenesis of hRMECs cells(all P<0.05). Knockdown of lncRNA MALAT1 significantly inhibited the proliferation, migration and tubule formation of hRMECs cells(all P<0.05). Dual-luciferase reporter gene assay showed that lncRNA MALAT1 targeted with miR-124-3p, and miR-124-3p targeted with SOX7. Overexpression of miR-124-3p significantly inhibited the proliferation, migration and tubule formation of hRMECs cells(all P<0.05). Overexpression of lncRNA MALAT1+miR-124-3p, miR-124-3p+SOX7, and knockdown of lncRNA MALAT1+overexpression of SOX7 all significantly eliminated the inhibitory effect of hRMECs cells(all P<0.05).

CONCLUSION: lncRNA MALAT1 promote the proliferation, migration and angiogenesis of retinal endothelial cells in diabetic retinopathy by down-regulating the negative regulation of miR-124-3p on SOX7. Therefore, abnormal upregulation of lncRNA MALAT1 in patients with diabetic retinopathy is a potential biomarker.