To investigate the effects of TSP1 on renal tubular epithelial cell injury and secretion of inflammatory factors induced by high glucose.

TSP-1 shRNA (shTSP-1) was transfected into renal tubular epithelial cells to silence TSP-1 gene. The renal tubular epithelial cells were divided into control group (treated with 5.6 mmol/L glucose), high glucose group (treated with 30 mmol/L glucose), NC + high glucose group (treated with 30 mmol/ L glucose, transfected with lentivirus control), interference + high glucose group (treated with 30 mmol/L glucose culture, transfected with TSP1 shRNA lentivirus). Realtime PCR and Western Blot were used to detect the effect of high glucose on the expression of TSP1 and the effect of TSP1 shRNA on the expression of TSP1. The level of ROS in cells was detected by DCFH-DA. The content of MDA in culture medium was detected by thiobarbituric acid. ELISA was used to detect TNF-α and IL-8 in the supernatant of the culture medium. Annexin V-FITC/PI double staining was used to detect apoptosis. Western Blot assay was used to detect c-caspase-3 in cells. Independent sample t test was used to compare the mean difference between the two groups, single factor analysis of variance was used to compare the difference among multiple groups, and SNK-q test was used to compare the two groups.

The levels of TSP1 mRNA and protein in the high glucose group were higher than those in the control group (P < 0.05). The levels of TSP1 mRNA and protein in the interference + high glucose group were lower than those in the high glucose group (P < 0.05). Compared with the control group, the level of ROS in the high glucose group increased, the contents of MDA, TNF-α and IL-8 increased in culture medium, the rate of apoptosis increased, the level of c-caspase-3 protein in the cells increased [ (2.36±0.21) nmol/ml, (45.91±2.87) ng/ml, (25.42±3.26) ng/ ml vs (1.05±0.13) nmol/ml, (20.14±1.36) ng/ml, (12.98±1.63) ng/ml], the difference has statistical significance (P < 0.05). Compared with high glucose group and NC + high glucose group, the level of ROS in the interference + high glucose group decreased, the contents of MDA, TNF-α and IL-8 in culture medium decreased, the apoptosis rate decreased, the level of c-caspase-3 decreased [ (1.63±0.10) nmol/ ml, (34.20±2.06) ng/ml, (18.75±1.62) ng/ml vs (2.36±0.21) nmol/ ml, (45.91±2.87) ng/ ml, (25.42±3.26) ng/ml和(2.30±0.42) nmol/ml, (46.32±5.24) ng/ml, (26.91±2.74) ng/ml], the difference has statistical significance (P < 0.05) .

High glucose induces TSP1 expression in renal tubular epithelial cells, down-regulation of its expression can inhibit high glucose-induced renal tubular epithelial cell injury and reduce cell secretion of inflammatory factors.