目的：观察长链非编码RNA(lncRNA)KCNQ1OT1通过miR-19a-3p/TSHZ3影响高糖(HG)诱导的人视网膜上皮细胞(ARPE-19)增殖、凋亡与氧化应激情况。

方法：运用细胞计数试剂盒8(CCK-8)检测5、15、45、135mmol/L HG刺激的ARPE-19的细胞存活率。将ARPE-19细胞分为NC组、45mmol/L HG组、si-NC+45mmol/L HG组、si-lncRNA KCNQ1OT1+45mmol/L HG组、miR-NC+45mmol/L HG组、miR-19a-3p mimics+45mmol/L HG组、si-con+45mmol/L HG组、si-TSHZ3+45mmol/LHG组、pcDNA+si-lncRNA KCNQ1OT1+45mmol/L HG组、pcDNA-TSHZ3+si-lncRNA KCNQ1OT1+45mmol/L HG组。运用CCK-8检测细胞存活率，qRT-PCR检测lncRNA KCNQ1OT1、miR-19a-3p和TSHZ3 mRNA表达，Western Blot检测TSHZ3、活化-含半胱氨酸的天冬氨酸蛋白水解酶3(Cleaved-caspase-3)、B细胞淋巴瘤/白血病-2(Bcl-2)相关X蛋白(Bax)蛋白质的表达，酶联免疫吸附测定法(ELISA)检测氧化应激指标活性氧(ROS)、丙二醛(MDA)水平。双荧光素酶活性检测lncRNA KCNQ1OT1和miR-19a-3p、miR-19a-3p和TSHZ3之间的靶向结合。

结果：15、45、135mmol/L HG抑制ARPE-19细胞的存活率，后续选择细胞存活率约50%的HG浓度45mmol/L。45mmol/L HG提高ARPE-19细胞中lncRNA KCNQ1OT1、TSHZ3 mRNA、TSHZ3蛋白表达水平、凋亡率、Cleaved-caspase-3、Bax蛋白表达、ROS和MDA水平，降低miR-19a-3p表达水平、细胞存活率(P<0.05)。lncRNA KCNQ1OT1、TSHZ3低表达或miR-19a-3p高表达提高HG诱导的ARPE-19细胞的存活率，降低凋亡率、Cleaved-caspase-3、Bax蛋白表达、ROS和MDA水平(P<0.05)。lncRNA KCNQ1OT1靶向miR-19a-3p，miR-19a-3p靶向TSHZ3，lncRNA KCNQ1OT13通过miR-19a-3p调控TSHZ3的表达。lncRNA KCNQ1OT1低表达对HG诱导的ARPE-19细胞存活率、凋亡以及氧化应激的影响被TSHZ3过表达所逆转。

结论：lncRNA KCNQ1OT13低表达通过miR-19a-3p/TSHZ3，促进HG诱导的ARPE-19，并抑制其凋亡和氧化应激。

METHODS: Cell counting kit 8(CCK-8)was used to detect the cell viability of human retinal epithelial cells ARPE-19 stimulated with 5, 15, 45, 135mmol/L HG. The ARPE-19 cells were divided into NC group, 45mmol/L HG group, si-NC+45mmol/L HG group, si-lncRNA KCNQ1OT1+45mmol/L HG group, miR-NC+45mmol/L HG group, miR-19a-3p mimics+45mmol/L HG group, si-con+45mmol/L HG group, si-TSHZ3+45mmol/L HG group, pcDNA+si-lncRNA KCNQ1OT1+45mmol/L HG group, pcDNA-TSHZ3+si-lncRNA KCNQ1OT1+45mmol/L HG group. CCK-8 was used to detect cell viability, qRT-PCR was used to detect the expressions of lncRNA KCNQ1OT1, miR-19a-3p and TSHZ3 mRNA, Western Blot was used to detect TSHZ3, activation-cysteine-containing aspartate proteolytic enzyme 3(Cleaved-caspase-3), B-cell lymphoma/leukemia-2(Bcl-2)related X protein(Bax)protein expressions, and enzyme-linked immunosorbent assay(ELISA)was used to detect the levels of oxidative stress indicators reactive oxygen species(ROS)and malondialdehyde(MDA). The dual luciferase activity was used to detect the targeted binding between lncRNA KCNQ1OT1 and miR-19a-3p, miR-19a-3p and TSHZ3.

RESULTS: 15, 45, 135mmol/L HG inhibited the survival rate of ARPE-19 cells, and the subsequent select the HG concentration 45mmol/L with a cell survival rate of about 50%. 45mmol/L HG increased the expression levels of lncRNA KCNQ1OT1, TSHZ3 mRNA, TSHZ3 protein, the apoptosis rate, Cleaved-caspase-3 and Bax protein expressions, ROS and MDA levels in ARPE-19 cells, and reduced cell survival rate and the expression level of miR-19a-3p(P<0.05). Low expression of lncRNA KCNQ1OT1, TSHZ3 or high expression of miR-19a-3p improved the survival rate of ARPE-19 cells induced by HG, and reduced apoptosis rate, Cleaved-caspase-3 and Bax protein expressions, ROS and MDA levels(P<0.05). lncRNA KCNQ1OT1 targeted miR-19a-3p, miR-19a-3p targeted TSHZ3, and lncRNA KCNQ1OT13 regulated the expression of TSHZ3 through miR-19a-3p. The effect of lncRNA KCNQ1OT1 low expression on the survival rate, apoptosis and oxidative stress of ARPE-19 cells induced by HG was reversed by the overexpression of TSHZ3.

CONCLUSION: The low expression of lncRNA KCNQ1OT13 promotes the proliferation of retinal epithelial cells induced by high glucose, and inhibits their apoptosis and oxidative stress through miR-19a-3p/TSHZ3.