Gpr97 Exacerbates AKI by Mediating Sema3A Signaling

Area of Science:

• Nephrology
• Molecular Biology
• Immunology

Background:

• G protein-coupled receptors (GPCRs) play crucial roles in renal function and pathophysiology.
• Gpr97, an adhesion GPCR family member, has an uncharacterized role in acute kidney injury (AKI).
• Investigating Gpr97's involvement in AKI is essential for understanding kidney disease mechanisms.

Purpose of the Study:

• To elucidate the role of Gpr97 in the development and progression of AKI.
• To determine the molecular mechanisms underlying Gpr97's function in renal injury.
• To explore Gpr97 as a potential therapeutic target for AKI.

Main Methods:

• Utilized Gpr97-deficient mice and wild-type controls in ischemia-reperfusion and cisplatin-induced AKI models.
• Assessed renal injury and inflammation via histological examination in mice and human patients with acute tubular necrosis.
• Employed microarray analysis, in vitro assays (siRNA knockdown, electrophoretic mobility shift assays, luciferase reporter assays), and Sema3A protein treatment to investigate molecular pathways.

Main Results:

• Gpr97 expression was upregulated in kidneys of mice and patients with AKI.
• Gpr97-deficient mice exhibited significantly reduced renal injury and inflammation compared to wild-type mice.
• Gpr97 deficiency attenuated AKI-induced semaphorin 3A (Sema3A) expression and modulated survivin, phosphorylated STAT3, and toll-like receptor 4 levels.

Conclusions:

• Gpr97 is a key mediator in AKI pathogenesis.
• Gpr97 deficiency mitigates renal injury and inflammation, partly through regulating Sema3A expression.
• Targeting Gpr97-mediated Sema3A signaling presents a promising novel therapeutic avenue for AKI.