Effect of circ_0084043 silence upon human renal tubular epithelial cell injury induced by high glucose

Objective To explore the effect of silencing circular RNA_0084043(circ_0084043) on the inflammatory responses, oxidative stress and apoptosis of human renal tubular epithelial cells induced by high glucose and its targeted regulation of miR-142-5p. Methods Renal tubular epithelial cells HK-2 were divided into the groups of Con, HG, HG+si-NC, HG+si-circ_0084043, HG+miR-NC, HG+miR-142-5p, HG+si-circ_0084043+anti-miR-NC and HG+si-circ_0084043+anti-miR-142-5p. Quantitative realtime polymerase chain reaction(qRT-PCR) was utilized for detecting the expression levels of circ_0084043 and miR-142-5p according to the random number table Enzyme-linked immunosorbent assay(ELISA) was utilized for detecting the levels of tumor necrosis factor-alpha(TNF-α) and interleukin-8(IL-8). The levels of malondialedhyde(MDA) and superoxide dismutase(SOD) were detected. Flow cytometry was employed for detecting apoptotic rate. Dual luciferase reporter gene was utilized for detecting the targeting relationship between circ_0084043 and miR-142-5p and Western blot for detecting the expressions of Bcl-2 and Bax protein. Results As compared with Con group, the expression level of circ_0084043 spiked in HG group(1.00±0.04) vs(3.57±0.49)(P<0.05) while the expression level of miR-142-5p declined(1.00±0.05) vs (0.34±0.06) (P<0.05);the levels of TNF-α, IL-8 and MDA(18.43±2.06) vs(49.55±2.65) mg/mL; (11.74±0.83) vs(27.62±2.25) mg/mL; (0.23±0.08) vs(2.86±0.37) nmol/mg(P<0.05), apoptotic rate(6.74±0.95)% vs(23.15±2.49)%and protein level of Bax increased(P<0.05) while activity of SOD decreased(40.05±3.07) vs(17.35±1.54) U/mg (P<0.05) and protein level of Bcl-2 dropped(P<0.05). Compared with HG/HG+si-NC group, the levels of TNF-α, IL-8 and MDA declined in HG+si-circ_0084043 group(49.55±2.65)/(48.42±4.04) vs(34.90±4.95) mg/mL; (27.62±2.25)/(27.76±3.53) vs(19.14±1.02) mg/mL; (2.86±0.37)/(2.81±0.43) vs (0.89±0.12) nmol/mg(P< 0.05) and apoptotic rate(23.15±2.49)/(23.73±3.28)% vs(14.47±0.93)%and protein level of Bax declined(P<0.05) while the activity of SOD(17.35±1.54)/(17.40±0.63) vs(28.54±2.56) U/mg (P<0.05) and protein level of Bcl-2 rose(P<0.05). And circ_0084043 could target miR-142-5p. As compared with HG+miR-NC group, the levels of TNF-α, IL-8 and MDA declined in HG+miR-142-5p group(48.78±4.56) vs(35.18±3.93) mg/mL; (27.98±1.64) vs(18.31±1.11) mg/mL; (2.81±0.32) vs(0.96±0.08) nmol/mg(P<0.05) and apoptotic rate(22.27±2.68)% vs(16.01±0.48)% and protein level of Bax dropped(P<0.05) while activity of SOD(17.40±1.09) vs(25.22±1.67) U/mg(P<0.05) and protein level of Bcl-2 rose(P<0.05). As compared with HG+si-circ_0084043+antimiR-NC group, the levels of TNF-α, IL-8 and MDA rose in HG+si-circ_0084043+anti-miR-142-5p group(34.74±1.51) vs(46.31±2.65) mg/mL; (19.03±0.66) vs(23.07±1.19) mg/mL; (0.89±0.06) vs(1.43±0.11) nmol/mg (P<0.05) and apoptotic rate(14.69±0.49)% vs(18.37±0.89)%and protein level of Bax spiked(P<0.05) while the activity of SOD(28.38±1.03) vs(19.56±0.83) U/mg (P<0.05) and protein level of Bcl-2 declined(P<0.05). Conclusion Silencing circ_0084043 could inhibit cell inflammatory responses, oxidative stress and apoptosis through negatively regulating miR-142-5p, thereby blunting the damage of human renal tubular epithelial cells induced by high glucose.