lncRNA PVT1 modulates NLRP3‑mediated pyroptosis in septic acute kidney injury by targeting miR‑20a‑5p

Abstract

Acute kidney injury (AKI) is the most common complication of sepsis. The current incidence of sepsis is high (0.3% of total population) worldwide, and septic AKI may cause death in patients. Long non‑coding (lnc)RNAs serve important roles in the pathogenesis of AKI. Therefore, the present study investigated the mechanism underlying lncRNA plasmacytoma variant translocation 1 (PVT1)‑mediated regulation of pyroptosis in septic AKI. Septic kidney injury was induced in mice using the caecal ligation and puncture method, and lipopolysaccharide (LPS)‑induced HK‑2 cell models were also established. Haematoxylin‑eosin staining was performed to assess pathological alterations of kidney tissues in the mice. The levels of IL‑1β, IL‑18 and lactate dehydrogenase were determined by conducting ELISAs. Reverse transcription‑quantitative PCR was used to detect the expression levels of PVT1 and microRNA (miR)‑20a‑5p. To assess pyroptosis, the protein expression levels of nucleotide‑binding oligomerization domain‑like receptor protein 3 (NLRP3), IL‑1β, IL‑18, apoptosis‑associated speck‑like protein containing a CARD and cleaved caspase‑1 were measured via western blotting. Flow cytometry was performed to assess the rate of cell pyroptosis. Dual luciferase reporter assays were used to assess the binding relationships of PVT1/miR‑20a‑5p and miR‑20a‑5p/NLRP3. PVT1 expression was significantly increased, whereas miR‑20a‑5p expression was significantly decreased in sepsis model mice and LPS‑induced HK‑2 cells compared with sham mice and control HK‑2 cells, respectively. PVT1 knockdown significantly suppressed cell pyroptosis and downregulated the expression of inflammatory factors in LPS‑induced HK‑2 cells. The results also indicated that PVT1 served as a sponge of miR‑20a‑5p, and miR‑20a‑5p directly targeted NLRP3. miR‑20a‑5p knockdown significantly promoted LPS‑induced cell pyroptosis. Moreover, PVT1 knockdown inhibited LPS‑induced cell pyroptosis by targeting the miR‑20a‑5p/NLRP3 signalling pathway. The results of the present study suggested that PVT1 modulated NLRP3‑mediated pyroptosis in septic AKI by targeting miR‑20a‑5p, which might suggest significant potential therapeutic targets for septic AKI.