Hemodynamic Disruption Triggers Glomerular Barrier Injury via Endothelial Glycocalyx Degradation in Nephrotic Syndrome

Nephrotic syndrome (NS) is a renal disorder characterized by severe proteinuria and generalized edema, frequently accompanied by a hypercoagulable state. Despite extensive clinical characterization, the mechanistic link between altered renal microhemodynamics and structural-functional disruption of the glomerular filtration barrier (GFB) remains incompletely understood. The endothelial glycocalyx (EG), a glycosaminoglycan-rich layer lining the vascular endothelium, serves as a critical mechanosensor and barrier regulator. Its degradation is implicated in increased vascular permeability and microcirculatory dysfunction. Here, we developed an integrated investigative platform combining an adriamycin (ADR)-induced NS rat model with in vitro microphysiological systems, including a vascular?on?a?chip (VOAC) and a glomerulus?on?a?chip (GOAC). The VOAC employed controlled laminar shear stress to evaluate EG morphology and endothelial responses in human umbilical vein endothelial cell (HUVEC) monolayers. The GOAC co?cultured HUVECs and podocytes in parallel microchannels separated by a porous membrane to quantify GFB permeability under defined flow conditions. In vivo, ADR-treated rats exhibited impaired shearstress-related hemodynamics, elevated fibrinogen (FBG) levels, increased whole?blood and plasma viscosity, enhanced erythrocyte aggregation, and shortened prothrombin time (PT) and activated partial thromboplastin time (APTT). EG injury was evidenced by reduced expressionof Syndecan?1, Glypican?1, and CD44, alongside increased urinary excretion of hyaluronic acid (HA) and heparan sulfate (HS). In both VOAC and GOAC models, low shear stress dose-dependently induced EG loss, cytoskeletal disorganization, upregulation of vascular adhesion molecules, and increased permeability to high?molecular?weight dextrans. Treatment with sulodexide significantly restored EG architecture, improved hemorheological parameters, attenuated adhesion molecule expression, and normalized microvascular barrier function both in vivo and in vitrosettings. These findings demonstrate that EG degradation is a pivotal event linking hemodynamic alterations to GFB injury in NS and highlight the potential of microphysiological organ-on-a-chip platforms for dissecting vascular pathophysiology and evaluating EG-targeted therapeutics.