AIM: To explore the effect of lncRNA SNHG6 on injury of human retinal microvascular endothelial cells(hRMECs)induced by high glucose and its possible mechanism.

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.