3-(2-4-dichloro-5-methoxyphenyl)-2-sulfanyl-4(3h)-quinazolinone and Acute-Kidney-Injury

Contrast-induced acute kidney injury (CI-AKI) is a serious and common complication in patients receiving intravenous iodinated contrast medium (CM). Clinically, congestive heart failure is the most critical risk factor for CI-AKI and always leads to renal congestion for increased central venous pressure and fluid overload. Here, we aimed to investigate a novel CI-AKI rat model based on renal congestion. After the exploratory testing phase, we successfully constructed a CI-AKI rat model by inducing renal congestion by clamping the unilateral renal vein, removing the contralateral kidney, and a single tail vein injection of iohexol. This novel CI-AKI rat model showed elevated serum creatinine, urea nitrogen, and released tubular injury biomarkers (KIM-1 and NGAL), reduced glomerular filtration rate, and typical pathologic features of CM-induced tubular injury with extensive foamy degeneration, tubular edema, and necrosis. Electron microscopy and confocal laser scanning revealed excessive mitochondrial fission and increased translocation of Drp1 from the cytoplasm to the mitochondrial surface in tubular epithelial cells. As a Drp1 inhibitor, Mdivi-1 attenuated excessive mitochondrial fission and exerted reno-protection against CM injury. Simultaneously, Mdivi-1 alleviated oxidative stress, apoptosis, and inflammatory responses induced by CM toxicity. We concluded that renal congestion exacerbated CM toxicity and presented a novel CI-AKI rat model. Excessive mitochondrial fission plays a crucial role in CM reno-toxicity and is a promising target for preventing and treating CI-AKI.

Topics: Acute Kidney Injury; Contrast Media; Humans; Kidney; Mitochondrial Dynamics

Mitochondria play an essential role in energy metabolism. Oxygen deprivation can poison cells and generate a chain reaction due to the free radical release. In patients with sepsis, the kidneys tend to be the organ primarily affected and the proximal renal tubules are highly susceptible to energy metabolism imbalances. Dynamin-related protein 1 (DRP1) is an essential regulator of mitochondrial fission. Few studies have confirmed the role and mechanism of DRP1 in acute kidney injury (AKI) caused by sepsis. We established animal and cell sepsis-induced AKI (S-AKI) models to keep DRP1 expression high. We found that Mdivi-1, a DRP1 inhibitor, can reduce the activation of the NOD-like receptor pyrin domain-3 (NLRP3) inflammasome-mediated pyroptosis pathway and improve mitochondrial function. Both S-AKI models showed that Mdivi-1 was able to prevent the mitochondrial content release and decrease the expression of NLRP3 inflammasome-related proteins. In addition, silencing NLRP3 gene expression further emphasized the pyroptosis importance in S-AKI occurrence. Our results indicate that the possible mechanism of action of Mdivi-1 is to inhibit mitochondrial fission and protect mitochondrial function, thereby reducing pyroptosis. These data can provide a potential theoretical basis for Mdivi-1 potential use in the S-AKI prevention.

Topics: Acute Kidney Injury; Animals; Apoptosis; Cell Line; Disease Models, Animal; Down-Regulation; Dynamins; Inflammasomes; Kidney Tubules; Lipopolysaccharides; Male; Mice, Inbred C57BL; Mitochondria; NLR Family, Pyrin Domain-Containing 3 Protein; Oxidative Stress; Quinazolinones; RNA, Small Interfering; Sepsis