LncRNA H19 overexpression protects against acute kidney injury after cardiopulmonary bypass via activating Pink1/Parkin-mediated mitophagy.

Background: Cardiopulmonary bypass-associated acute kidney injury (CPB-AKI) is a serious and common complication following cardiopulmonary bypass (CPB), leading to worse outcomes and higher mortality. However, the underlying pathological mechanisms of CPB-AKI remain largely unknown. This study aimed to investigate the role of long non-coding RNA H19 (H19) in regulating CPB-AKI.

Methods: We examined the expressions of H19 and mitophagy-related proteins in a CPB-AKI rat model and HK-2 cells following oxygen-glucose deprivation/reperfusion (OGD/R). In vivo, lentiviral-mediated overexpression of H19 was induced in the kidney through tail vein injection. We then evaluated renal functions, kidney pathological damage, levels of inflammatory cytokines (tumor necrosis factor-α, interleukin (IL)-1β, IL-6, and IL-10), neutrophil infiltration, and the activation of PTEN-induced putative kinase 1 (Pink1)/Parkin-mediated mitophagy following CPB-AKI. In vitro, small interfering RNA (siRNA) was used to downregulate H19 expression in HK-2 cells. We also examined cell viability, apoptosis, inflammation, and Pink1/Parkin-mediated mitophagy after OGD/R.

Results: We demonstrated an increase in H19 expression and activation of Pink1/Parkin-mediated mitophagy in the rat model of CPB-AKI and HK-2 cells following OGD/R. In the rat models of CPB-AKI, lentivirus-mediated overexpression of H19 significantly attenuated renal injury, characterized by better renal function, reduced tissue damage, decreased neutrophil infiltration, and lower inflammatory cytokine release (P <0.05). Notably, overexpression of H19 significantly activated Pink1/Parkin-mediated mitophagy. Furthermore, in vitro, downregulation of H19 by specific siRNA in HK-2 cells significantly decreased cell viability, worsened HK-2 injury after OGD/R, increased inflammatory cytokine release, and decreased Pink1/Parkin-mediated mitophagy activity, promoting cell apoptosis (P <0.05).

Conclusions: These findings suggest that H19 overexpression may protect against CPB-AKI by activating Pink1/Parkin-mediated mitophagy and decreasing inflammatory responses and cellular apoptosis. Thus, H19 overexpression might be a promising therapeutic target for treating CPB-AKI.