Abstract
Background and Purpose
Obesity, an important risk factor for developing chronic kidney disease (CKD), affects the kidneys by two main molecular signalling pathways: the endocannabinoid/CB1 receptor system, whose activation in obesity promotes renal inflammation, fibrosis, and injury, and the inducible NOS (iNOS), which generates ROS resulting in oxidative stress. Hence, a compound that inhibits both peripheral CB1 receptors and iNOS may serve as an effective therapeutic agent against obesity-induced CKD.
Experimental Approach
Here, we describe the effect of a novel peripherally restricted, orally bioavailable dual CB1 receptor/iNOS antagonist, MRI-1867 (3 mg·kg−1), in ameliorating obesity-induced CKD, and compared its metabolic and renal efficacies to a stand-alone peripheral CB1 receptor antagonist (JD5037; 3 mg·kg−1), iNOS antagonist (1400W; 10 mg·kg−1), and pair feeding. Mice with high-fat diet-induced obesity were treated orally with these compounds or vehicle (Veh) for 28 days. Standard diet-fed mice treated with Veh served as controls.
Key Results
Enhanced expression of CB1 receptors and iNOS in renal tubules was found in human kidney patients with obesity and other CKDs. The hybrid inhibitor ameliorated obesity-induced kidney morphological and functional changes via decreasing kidney inflammation, fibrosis, oxidative stress, and renal injury. Some of these features were independent of the improved metabolic profile mediated via inhibition of CB1 receptors. An additional interesting finding is that these beneficial effects on the kidney were partially associated with modulating renal adiponectin signalling.
Conclusions and Implications
Collectively, our results highlight the therapeutic relevance of blocking CB1 receptors and iNOS in ameliorating obesity-induced CKD.