Abstract

BACKGROUND: Reactive oxygen species (ROS) and inflammation both contribute to the progression of aldosterone-induced renal injury. To better understand the underlying mechanisms, we examined mitochondrial dysfunction and NLRP3 inflammasome activation in aldosterone-infused rats, and explored the role of rotenone in attenuating these injuries.

MATERIAL AND METHODS: Sprague-Dawley rats were divided into 3 groups: vehicle-treated, aldosterone-infused, and aldosterone plus rotenone. Renal damage was evaluated using PAS staining and electron microscopy. Levels of ROS were measured from renal tissue and serum; immunohistochemistry analysis examined the inflammation pathway; Western blot and real-time PCR assessed NLRP3 inflammasome activity.

RESULTS: Glomerular segmental sclerosis, foot process effacement, and proteinuria were demonstrated in the aldosterone-infused rats. Specifically, the thiobarbituric acid-reactive substances (TBARS) oxidative stress marker, MDA, was significantly increased; ATP content and mtDNA copy number were markedly decreased; inflammatory mediators NF-κB p65 and CTGF were upregulated; and NLRP3 inflammasome and its related target proteins, IL-1β and IL-18, were also increased. Treatment with rotenone, an inhibitor of mitochondrial complex I, significantly attenuated oxidative stress, mitochondrial dysfunction, and inflammasome response in aldosterone-infused rats.

CONCLUSIONS: Rotenone ameliorated aldosterone-infused renal injury, possibly by inhibiting oxidative stress, mitochondrial dysfunction, and NLRP3 inflammasome activity. These results provide novel evidence for the role of rotenone in aldosterone-induced renal injury or other chronic kidney disease.

Keywords: Aldosterone - chemistry, Adenosine Triphosphate - chemistry, Carrier Proteins - metabolism, DNA, Mitochondrial - metabolism, Glomerulosclerosis, Focal Segmental - pathology, Inflammasomes - metabolism, Inflammation - metabolism, Kidney - pathology, Malondialdehyde - chemistry, Microscopy, Electron, Mitochondria - pathology, Proteinuria - pathology, Reactive Oxygen Species - metabolism, Real-Time Polymerase Chain Reaction, Rotenone - metabolism, Thiobarbituric Acid Reactive Substances - chemistry, Transcription Factor RelA - metabolism