Pulmonary surfactants and the respiratory-renal connection in steroid-sensitive nephrotic syndrome of childhood
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ABSTRACT: Summary Steroid-sensitive nephrotic syndrome (SSNS) in childhood is usually due to minimal change disease (MCD). Unlike many glomerular conditions, SSNS/MCD is commonly precipitated by respiratory infections. Of interest, pulmonary inflammation releases surfactants in circulation which are soluble agonists of SIRPα, a podocyte receptor that regulates integrin signaling. Here, we characterized this pulmonary-renal connection in MCD and performed studies to determine its importance. Children with SSNS/MCD in relapse but not remission had elevated plasma surfactants and urinary SIRPα. Sera from relapsing subjects triggered podocyte SIRPα signaling via tyrosine phosphatase SHP-2 and nephrin dephosphorylation, a marker of podocyte activation. Further, addition of surfactants to MCD sera from patients in remission replicated these findings. Similarly, nasal instillation of toll-like receptor 3 and 4 agonists in mice resulted in elevated serum surfactants and their binding to glomeruli triggering proteinuria. Together, our data document a critical pulmonary-podocyte signaling pathway involving surfactants and SIRPα signaling in SSNS/MCD. Graphical abstract Highlights • A key pulmonary-renal interplay is evidenced in minimal change disease• Urinary SIRPα is elevated in subjects with steroid-sensitive nephrotic syndrome• Circulating surfactants, soluble SIRPα ligands, are elevated in minimal change disease• Surfactants interact with SIRPα in podocytes causing foot effacement and proteinuria Health sciences; Nephrology; Cell biology
SUBMITTER: Cara-Fuentes G
PROVIDER: S-EPMC9284382 | biostudies-literature |
REPOSITORIES: biostudies-literature
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