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

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-1 beta, 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-1 beta, 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.