MiR-133a alleviates renal injury caused by sepsis by targeting BNIP3L.

Abstract

Sepsis is an important cause of acute kidney injury (AKI), seriously jeopardizing the health of patients. This paper's aim was to investigate whether microRNA-133a had a protective effect on sepsis-induced kidney injury. We established a kidney injury model with lipopolysaccharide (LPS) and divided TCMK-1 cells into 4 groups: control group (con); LPS treatment group; LPS + negative control (NC) treatment group; LPS + miR-133a mimic (mim) group. The expressions of miR-133a, TNF-α mRNA, IL-6 mRNA, Bax mRNA, Bcl-2 mRNA, BNIP3L mRNA, IκKα Mrna and IκB-α mRNA were detected by PCR. Western blot was used to detect the protein expression of TNF-α, IL-6, Bax, Bcl-2, BNIP3L, IκKα and IκB-α. Cell viability was measured by cell counting kit-8 (CCK-8). Flow cytometry was utilized to detect apoptosis rate. IL-1β immunofluorescence and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) staining were used to observe the inflammation and apoptosis in TCMK-1 cells. The miR-133a expression was decreased in TCMK-1 cells treated with LPS. In the LPS treatment group, the expression of TNF-α, IL-6, Bax, BNIP3L and IκKα increased, and the expression of Bcl-2 and IκB-α decreased. When overexpressing miR-133a, the protein and mRNA expression of TNF-α, IL-6, Bax, BNIP3L and IκKα decreased markedly, while the expression of Bcl-2 and IκB-α increased markedly. Compared with the LPS-treated group, the apoptotic rate, the number of TUNEL-positive cells, and the immunofluorescence intensity of IL-1β in LPS+mim group were greatly decreased. The miR-133a expression was decreased in TCMK-1 cells treated by LPS and miR-133a can inhibit inflammation and apoptosis of TCMK-1 cells induced by LPS by targeting BNIP3L via inhibiting NF-κB pathway.