Melanocortin 5 receptor signaling protects against podocyte injury in proteinuric glomerulopathies.

Kidney Int

Division of Nephrology, Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio, USA; Division of Kidney Disease and Hypertension, Rhode Island Hospital, the Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA. Electronic address:

Published: January 2025

Melanocortin therapeutics, exemplified by adrenocorticotropic hormone, have a proven steroidogenic-independent anti-proteinuric and glomerular protective effect. The biological functions of melanocortins are mediated by melanocortin receptors (MCR), including MC1R, which recent studies have shown to protect against glomerular disease. However, the role of other MCRs like MC5R is unknown. Here, MC5R knockout exacerbated glomerulopathy in mice injured by adriamycin (ADR) or nephrotoxic serum (NTS), as demonstrated by increased albuminuria and podocyte injury. Conversely, selective MC5R agonism using a peptidomimetic agonist improved outcomes of glomerulopathies. Mechanistically, MC5R is expressed in glomerular podocytes. Reconstitution of MC5R in podocytes attenuated glomerular injury and proteinuria in MC5R knockout mouse models of glomerulopathies, indicating a direct podocyte protective effect. In vitro, MC5R agonism in primary wild-type podocytes attenuated ADR-elicited cytoskeleton disruption, hypermotility and apoptosis, associated with restored inhibitory phosphorylation of glycogen synthases kinase 3β (GSK3β), a signaling transducer downstream of MC5R and at the nexus of multiple podocytopathic pathways. In parallel, ADR-induced phosphorylation and activation of GSK3β substrates, such as paxillin and NFκB RelA/p65, were abrogated, leading to improved actin cytoskeleton integrity and diminished expression of mediators of podocyte injury, like MCP-1, B7-1 and Cathepsin L. This protective effect of MC5R agonism was blunted in wild-type podocytes expressing constitutively active GSK3β and was mimicked in MC5R knockout podocytes by ectopic expression of dominant negative GSK3β. Consistently in ADR-injured MC5R knockout mice, worsened podocytopathy was associated with enhanced GSK3β hyperactivity. These findings suggest that MC5R signaling protects against podocyte injury and may serve as a novel therapeutic target for glomerular diseases.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.kint.2025.01.009DOI Listing

Publication Analysis

Top Keywords

podocyte injury
16
mc5r knockout
16
mc5r
12
mc5r agonism
12
signaling protects
8
protects podocyte
8
podocytes attenuated
8
wild-type podocytes
8
podocyte
5
injury
5

Similar Publications

Melanocortin 5 receptor signaling protects against podocyte injury in proteinuric glomerulopathies.

Kidney Int

January 2025

Division of Nephrology, Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio, USA; Division of Kidney Disease and Hypertension, Rhode Island Hospital, the Warren Alpert Medical School of Brown University, Providence, Rhode Island, USA. Electronic address:

Melanocortin therapeutics, exemplified by adrenocorticotropic hormone, have a proven steroidogenic-independent anti-proteinuric and glomerular protective effect. The biological functions of melanocortins are mediated by melanocortin receptors (MCR), including MC1R, which recent studies have shown to protect against glomerular disease. However, the role of other MCRs like MC5R is unknown.

View Article and Find Full Text PDF

Background: Although recent progress provides mechanistic insights into diabetic nephropathy (DN), effective treatments remain scarce. DN, characterized by proteinuria and a progressive decline in renal function, primarily arises from podocyte injury, which impairs the glomerular filtration barrier. Wogonoside, a bioactive compound from the traditional Chinese herb Scutellaria baicalensis, has not been explored for its role in DN.

View Article and Find Full Text PDF

Autophagy and mitophagy are critical cellular processes that maintain homeostasis by removing damaged organelles and promoting cellular survival under stress conditions. In the context of diabetic kidney disease, these mechanisms play essential roles in mitigating cellular damage. This review provides an in-depth analysis of the recent literature on the relationship between autophagy, mitophagy, and diabetic kidney disease, highlighting the current state of knowledge, existing research gaps, and potential areas for future investigations.

View Article and Find Full Text PDF

Several microRNAs (miRNAs) emerged as powerful regulators of fibrotic processes, "fibromiRs", and can also influence the expression of genes responsible for the generation of reactive oxygen species, "redoximiRs". We aimed to investigate whether plasma exosomes from hypertensive and diabetes patients are enriched in fibromiRs and redoximiRs using deep sequencing technology and their association with relevant signalling pathways implicated in oxidative stress and fibrogenesis by GO terms and KEGG pathways. RNA-Seq analysis from P-EXO identified 31 differentially expressed (DE) miRNAs in patients compared to controls, of which 77% are biofluid specific.

View Article and Find Full Text PDF

Diabetic kidney disease (DKD) is a leading cause of chronic kidney disease (CKD) and end-stage renal disease worldwide, affecting approximately 40% of individuals with type 2 diabetes (T2DM) and 30% of those with type 1 diabetes (T1DM). As the prevalence of diabetes continues to rise, the burden of DKD is expected to grow correspondingly. This review explores the roles of key molecular pathways, including the apelinergic system, vascular endothelial growth factor (VEGF)/VEGF receptor (VEGFR) axis, and nitric oxide (NO)/nitric oxide synthase (NOS) signaling, in DKD pathogenesis and potential therapeutic applications.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!