Announcement
Thank you for attending THSNA 2026. The virtual meeting is now closed.
Thank you for attending THSNA 2026. The virtual meeting is now closed.
Presentation Details
| Factor X deficiency does not fully recapitulate the effects of prothrombin knockdown on podocytopathy during proteinuric glomerular disease (THSNA �Travel Awardee) Kaushik Muralidharan1, Amanda Waller1, Katelyn Wolfgang1, Mayra Oseguera1, Eman Abdelghani2, Brittney Spruill1, Bryce Kerlin1, 3. 1Center for Clinical and Translational Research, Abigail Wexner Research Institute at Nationwide Childrens Hospital, Columbus, OH, USA.2Indiana Hemophilia and Thrombosis Center, Indianapolis, IN, USA.3Faculty of Medicine at The Ohio State University, Columbus, OH, USA |
Abstract
Background: New therapeutic strategies for proteinuric glomerular disease are urgently needed to reduce morbidities and mortalities associated with End-stage kidney disease (ESKD). We previously demonstrated that thrombin interacts with and directly damages podocytes through PAR heterodimers. In rat models of glomerular disease, (pro)thrombin (fII) knockdown and both direct (dabigatran) and indirect (rivaroxaban) (pro)thrombin antagonism improved podocyte injury, disease activity, and progression. However, the mechanisms behind intraglomerular thrombin generation during proteinuria remain unknown. This study aimed to determine if factor X knockdown would mirror the effects of prothrombin knockdown during glomerular disease. Methods: Prothrombin- and factor X-knockdown mice (F2lox/- and F10Friuli/Friuli, respectively) were crossed with podocin-Cre; inducible diphtheria toxin receptor mice and compared to wild-type (WT) mice with normal F2 and F10 loci (N=12-16/group). On Day 0, podocyte-specific proteinuria was induced by a single intraperitoneal injection of 1 ng/g diphtheria toxin (DT) vs no DT. Spot urine samples were collected every 4-7 days to measure albumin:creatinine ratios. Transcutaneous FITC-sinistrin Glomerular Filtration Rate (GFR) was determined at baseline and Day 34. Tissues and blood were collected on Day 35. Glomeruli were isolated and analyzed by flow cytometry for podocyte cell death. Results: Prothrombin and factor X activities were 9.7% ± 2.63 and 15.9% ± 7.54 of WT levels in the F2lox/- and F10Friuli/Friuli mice, respectively (P<0.001). Compared to WT mice, F2lox/- mice had 27.5% ± 3.62 less albuminuria from days 9 to 35 (P<0.001), while albuminuria in the F10Friuli/Friuli mice was 10.2% ± 3.51 decreased compared to WT over the same period (P = 0.250). By day 34, GFR in the WT mice was 34.2% ± 1.88 lower than healthy control mice (1.44 ± 0.08 vs 2.19 ± 0.17 mL/min/100g body weight in the WT vs control mice, respectively; P=0.043). Prothrombin knockdown improved day 34 GFR, resulting in a 29.3% ± 2.68 increase in the F2lox/- mice (2.04 ± 0.19 mL/min/100 g body weight; P = 0.010 vs. WT). In contrast, day 34 GFR in the F10Friuli/Friuli mice was 1.67 ± 0.16 mL/min/100g body weight; a 13.6% ± 1.32 improvement over WT levels (P=0.224; NS). Prothrombin knockdown also reduced in situ podocyte injury at day 35, such that the proportion of TUNEL-positive podocytes was 26.4% ±1.61 decreased in the F2lox/- mice compared to WT mice (P<0.042), whereas F10Friuli/Friuli mice were 9.7% ±1.78 decreased (P=0.104; NS). Discussion: Prothrombin knockdown reduced albuminuria, alleviated podocytopathy, and improved glomerular function in a mouse model of proteinuric glomerular disease, recapitulating prior observations in rat models. In contrast, factor X knockdown did not significantly improve the disease in this model, indicating that factor X likely does not have a major role in intraglomerular thrombin production during proteinuria. These results further support that thrombin is a central factor in proteinuric glomerular disease; however, how thrombin is produced within the glomerulus remains unknown, and identifying this process could lead to new therapeutic targets. Ongoing research is investigating an alternative prothrombinase that might contribute to intraglomerular thrombin production during proteinuria. These studies involve administering rivaroxaban to mice, a direct FXa inhibitor.
No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the author.
No part of this publication may be reproduced, distributed, or transmitted in any form or by any means, including photocopying, recording, or other electronic or mechanical methods, without the prior written permission of the author.