S-nitrosoglutathione inhibits pyroptosis of kidney tubular epithelial cells in sepsis via the SIRT3/SOD2/mtROS signaling pathway.

Objectives: Pyroptosis is considered to play an important role in the occurrence, development and prognosis of septic acute kidney injury (SAKI). We aimed to explore the specific molecular mechanism of S-nitrosoglutathione (SNG) regulating pyroptosis of kidney tubular epithelial cells (KTECs).

Methods: By constructing a mice model of sepsis, we pretreated them with SNG and used biochemical methods to detect the levels of serum inflammatory factors and mitochondrial reactive oxygen species (mtROS), assessed the severity of kidney injury and KTECs mitochondrial damage, and detected the expression of KTECs pyroptosis-related proteins and sirtuin 3 (SIRT3)/superoxide dismutase 2 (SOD2) pathway proteins.

Results: The kidney injury caused by sepsis was significantly aggravated, and the levels of IL-1β, IL-6, IL-18, TNF-α, malondialdehyde (MDA) and mtROS were all increased, accompanied by the decrease of SIRT3 and SOD2 proteins, while NOD-like receptor with pyrin domain 3 (NLRP3), gasdermin D (GSDMD), Caspase-1 proteins expression and the number of KTECs apoptotic cells were all increased. However, after SNG pretreatment, the levels of IL-1β, IL-6, IL-18, TNF-α, MDA and mtROS were all significantly decreased, the expression of SIRT3 and SOD2 proteins were increased, NLRP3, GSDMD, Caspase-1 proteins expression and the number of KTECs apoptotic cells were decreased.

Conclusions: SNG protects SAKI by regulating the SIRT3/SOD2/mtROS signaling pathway to inhibit the pyroptosis of KTECs.