Abstract Body: Introduction: In the United States, 50-80% of chronic kidney disease (CKD) patients use a central venous catheter (CVC) for hemodialysis. Protracted exposure of CVCs against fragile venous walls results in central venous stenosis (CVS), which has devastating complications. Despite its higher prevalence of up to 40% in CKD patients, little is known about its pathogenesis and the means to target it.
Hypothesis: We posit that a venous guide-wire injury will induce specific perturbation in the target cells (endothelial and vascular smooth muscle cells) in the CKD milieu.
Methods: Twenty-two 8-12-week-old Sprague Dawley rats on 0.75 % Adenine diet (CKD rats) for two weeks and N=18 normal chaw (control ) were subjected to guide wire injury on their right internal jugular veins. After the injury, animals were harvested on days 0, 5, and 14. GeoMax Whole transcriptome analysis, validation, and molecular studies were performed after validation studies.
Results: Compared to non-CKD rats, injured veins of CKD rats showed higher thrombus, deposition of extracellular matrix, and perivascular fibrosis, all consistent with CVS. Spatial transcriptomics analysis revealed significant (P < 0.05) and at least more than 50% upregulation of genes of matrix modifying enzymes (MMP 10 and 19), collagen, and others. OF these changes, a consistent 1.6 to 2-fold upregulation was noted in the Tumor Necrosis Factor (TNF) family members (Tnfrsf1b, Traf3, ifnb1, Tradd) in endothelial and vascular smooth muscle cells. This finding was validated using IHC, which demonstrated TNF-alpha upregulation in the endothelial cells of the injured veins of CKD rats (P= 0.002, P <0.0001 at days 5 and 14) compared to controls. Mechanistic probing revealed that endothelial cells exposed to the serum from CKD patients suppressed survival and migration (P <0.05), both of which were reversed by anti-TNF neutralizing antibodies (P =0.05) through the JNK and Phospho p-38 pathway. At the same time, no effect was noted in primary human vascular smooth muscle cells.
Conclusion: Leveraging a rodent model of CVS, this study generates and validates the first central venous stenosis model in rats, demonstrating higher perivascular fibrosis in the CKD milieu. The spatiotemporal genetic perturbation in the injured vein of CKD rats, showing the multitude of pathways perturbed by the injury in the CKD milieu of TNF, can be therapeutically targeted with FDA-approved TNF agents.