目的：探讨lncRNA SNHG6对高糖诱导的人视网膜微血管内皮细胞(hRMECs)损伤的影响及其可能的作用机制。

方法：采用高糖诱导hRMECs建立细胞损伤模型。高糖(HG)组将hRMECs培养在浓度为25 mmol/L D-葡萄糖的DMEM培养基24 h； 正常(NG)组将hRMECs培养在浓度为5.5 mmol/L D-葡萄糖的DMEM培养基； 按照实验设计分别将si-NC、si-SNHG6、 si-SNHG6和anti-miR-NC、si-SNHG6和anti-miR-186-5p转染至hRMECs，随后25 mmol/L D-葡萄糖孵育24 h，分别记为HG+si-NC组、HG+si-SNHG6组、HG+si-SNHG6+anti-miR-NC组、HG+si-SNHG6+anti-miR-186-5p组。qRT-PCR法检测lncRNA SNHG6、miR-186-5p的表达量； 双荧光素酶报告实验检测lncRNA SNHG6与miR-186-5p的靶向关系； MTT法与流式细胞术分别检测细胞增殖及凋亡； ELISA法检测IL-1β、TNF-α、IL-8、IL-10的水平； 采用试剂盒检测SOD的活性和MDA的水平； Western blot检测cleaved-caspase3、Bax、Bcl-2蛋白表达量。

结果：HG组与NG组比较lncRNA SNHG6表达升高，miR-186-5p表达降低(均P<0.05)； lncRNA SNHG6可靶向结合miR-186-5p。转染si-SNHG6后细胞增殖抑制率、凋亡率、cleaved-caspase3、Bax蛋白水平，IL-1β、TNF-α、IL-8含量以及MDA活性降低(P<0.05)，而Bcl-2蛋白、IL-10含量以及SOD的活性升高(P<0.05)。共转染si-SNHG6和anti-miR-186-5p后，细胞增殖抑制率、凋亡率、cleaved-caspase3、Bax、IL-1β、TNF-α、IL-8以及MDA升高(P<0.05)，而Bcl-2蛋白、IL-10和SOD降低(P<0.05)。

结论：干扰lncRNA SNHG6表达可通过促进miR-186-5p表达而抑制高糖诱导的hRMECs凋亡、炎症反应及氧化应激。

METHODS: The D-glucose-induced hRMECs were used to establish normal glucose(NG)and high glucose(HG)cell injured model. In the HG group, the hRMECs were cultured in DMEM medium at a concentration of 25 mmol/L D-glucose for 24 h, while in the NC group, they were cultured in DMEM medium at a concentration of 5.5 mmol/L D-glucose; according to experimental design, si-NC, si-SNHG6, si-SNHG6 and anti-miR-NC and si-SNHG6 and anti-miR-186-5p were transfected into hRMECs, and then incubated at a concentration of 25 mmol/L D-glucose for 24 h, with HG+si-NC group, HG+si-SNHG6 group, HG+si-SNHG6+anti-miR-NC group and HG+si-SNHG6+anti-miR-186-5p group marked, respectively. The quantitative real-time polymerase chain reaction(qRT-PCR)was used to detect the expression of lncRNA SNHG6 and miR-186-5p; dual-luciferase reporter assay was used to detect the targeting relationship; MTT assay and flow cytometry were used to detect the cell proliferation and apoptosis, respectively; enzyme linked immunosorbent assay(ELISA)was used to detect the levels of IL-1β, TNF-α, IL-8, IL-10; testing kits were used to detect activity of SOD and level of MDA; the Western blot was used to detect the protein expression of cleaved-caspase3, Bax and Bcl-2.

RESULTS: The lncRNA SNHG6 expression increased in the HG group, while miR-186-5p expression decreased(both P<0.05). There was target binding of lncRNA SNHG6 with miR-186-5p. After the transfection of si-SNHG6, cell inhibition rate, apoptosis rate, cleaved-caspase3, Bax protein levels, IL-1β, TNF-α, IL-8 contents, and MDA activity were decreased(P<0.05), while Bcl-2 protein, IL-10 contents, and SOD activity were increased(P<0.05). Co-transfection of si-SNHG6 and anti-miR-186-5p increased cell proliferation inhibition rate, apoptosis rate, cleaved-caspase3, Bax, IL-1β, TNF-α, IL-8, and MDA(P<0.05), but decreased Bcl-2, IL-10 and SOD(P<0.05).

CONCLUSION: Interfering with lncRNA SNHG6 could inhibit cell apoptosis, inflammation and oxidative stress of high-glucose- induced hRMECs by elevating the expression of miR-186-5p.