From Glomerular Endothelial Remodeling to Kidney Protection: Emerging Molecular Mechanisms and Biomarker Signatures of GLP-1 Receptor Agonists

Kidney-protective therapies for diabetes mellitus have evolved rapidly in recent years, with glucagon-like peptide-1 receptor agonists (GLP-1RAs) offering renal protection. While some recent clinical trials have shown kidney benefits of these agents that extend well beyond improvements in blood glucose levels and reductions in albuminuria, much is still unknown about the precise molecular mechanisms. In this narrative review, we critically summarize the clinical and mechanistic evidence for GLP-1RA kidney protection, focusing on renal receptor localization, changes in glomerular endothelial cells, inflammatory signaling, mitochondrial dysfunction, and extracellular matrix turnover. We highlight recent results from the FLOW trial, which showed clinically significant kidney benefits with semaglutide, and from the REMODEL trial, which combines renal imaging with single-nucleus RNA sequencing and spatial transcriptomics. Although REMODEL did not demonstrate significant improvements in its coprimary imaging endpoints, exploratory molecular analyses identified treatment-associated changes in glomerular endothelial transcriptional programs and predicted endothelial–immune cell interactions. These findings suggest that microvascular remodeling may contribute to renal protection, although direct glomerular endothelial cell GLP1 receptor expression remains to be confirmed. In experimental systems, the pathways identified also involve control of oxidative stress, inflammasome activation, regulation of mitochondrial function, podocyte health, and fibrosis-related signaling, but their causal role in human kidney disease is yet to be proven. Novel proteomic and extracellular matrix biomarkers, such as tumor necrosis factor receptors, kidney injury molecule-1, and markers of collagen turnover, may help phenotype biological treatment responses beyond classical kidney function and albuminuria measures. Finally, tissue-based molecular phenotyping, combined with circulating and urinary markers, may resolve robust molecular signatures, and separating direct receptor effects from secondary systemic effects will be critical to translating GLP-1RA-mediated kidney benefit into biomarker-based nephrology.