Neutrophil extracellular traps drive tubulointerstitial fibrosis via the coiled-coil domain-containing protein 25 (CCDC25)-Yes-associated protein 1 (YAP1) axis-mediated autophagy regulation

Background and purpose: Tubulointerstitial fibrosis (TIF) is a pathological hallmark of chronic kidney disease (CKD) without effective therapy. Neutrophil extracellular traps (NETs) are complex web-like structures released by activated neutrophils, but their functional contribution to CKD-TIF remains largely unknown. Here, we uncovered a novel pathological role of NETs in driving TIF development.

Experimental approach: NETs levels were evaluated in human kidney biopsies and serum samples. Peptidylarginine deiminase 4 (PAD4) knockout mice were subjected to unilateral ureteral obstruction and adenine-induced nephropathy models. The underlying mechanisms were elucidated by RNA Sequencing, transmission electron microscopy, molecular docking and co-immunoprecipitation. The PAD4 inhibitor GSK484 was administered to evaluate the role of NETs in TIF.

Key results: NETs markedly accumulated in kidneys of CKD patients and murine models, positively correlating with renal dysfunction and fibrosis progression. PAD4 knockout suppressed NETs formation and attenuated TIF. Mechanistically, transcriptomic analyses displayed pronounced activation of autophagy-related pathways in NETs-stimulated fibroblasts, whereas Autophagy inhibition suppressed fibroblast activation. NETs components interacted with the transmembrane receptor coiled-coil domain-containing protein 25 (CCDC25), triggering dissociation of Yes-associated protein 1 (YAP1) from its receptor. This molecular rearrangement facilitates YAP1 nuclear translocation, subsequently enhancing autophagic activity in fibroblasts and promoting their phenotypic transition into myofibroblasts. Therapeutic administration of the PAD4 inhibitor GSK484 significantly attenuated renal fibrosis in vivo.

Conclusions and implications: Our study provides the first evidence that NETs exacerbate CKD-TIF by enhancing fibroblast Autophagy via the CCDC25-YAP1 axis, highlighting the NETs inhibitor GSK484 as a promising therapeutic candidate.