Aim: Kidney impairment is observed in patients with COVID-19. The effect of anti-COVID-19 agent remdesivir on kidneys is currently unknown. We aimed to determine the effect of remdesivir on renal fibrosis and its downstream mechanisms.Methods: Remdesivir and its active nucleoside metabolite GS-441524 were used to treat TGF-β stimulated renal fibroblasts (NRK-49F) and human renal epithelial (HK2) cells. Vehicle or remdesivir were given by intraperitoneal injection or renal injection through the left ureter in unilateral ureteral obstruction (UUO) mice. Serum and kidneys were harvested. The concentrations of remdesivir and GS-441524 were measured using LC-MS/MS. Renal and liver function were assessed. Renal fibrosis was evaluated by Masson’s trichrome staining and Western blotting.Results: Remdesivir and GS-441524 inhibited the expression of fibrotic markers (fibronectin and aSMA) in NRK-49F and HK2 cells. Intraperitoneal injection or renal injection of remdesivir attenuated renal fibrosis in UUO kidneys. Renal and liver function were unchanged in remdesivir treated UUO mice. Two remdesivir metabolites were detected after injection. Phosphorylation of Smad3 that was enhanced in cell and animal models for renal fibrosis was attenuated by remdesivir. In addition, the expression of Smad7, an anti-fibrotic factor, was increased after remdesivir treatment in vitro and in vivo. Moreover, knockdown of Smad7 blocked the antifibrotic effect of GS and RDV on renal cells.Conclusion: Remdesivir inhibits renal fibrosis in obstructed kidneys.

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Aim: Kidney impairment is observed in patients with . We aimed to demonstrate the effect of anti-COVID-19 agent remdesivir on renal fibrosis.Methods: Remdesivir and its active nucleoside metabolite GS-441524 were used to treat TGF-β stimulated renal fibroblasts (NRK-49F) and human renal epithelial cells (HK2). Cell viability was determined by CCK8 assay, and fibrotic markers were measured by Western blotting. Vehicle or remdesivir were given by intraperitoneal injection or renal injection through the left ureter in unilateral ureteral obstruction (UUO) mice. Serum and kidneys were harvested. The concentrations of remdesivir and GS-441524 were measured using LC-MS/MS. Renal and liver function were assessed. Renal fibrosis was evaluated by Masson's trichrome staining and Western blotting. Results: Remdesivir and GS-441524 inhibited cell proliferation and the expression of fibrotic markers (fibronectin, pSmad3, and aSMA) in NRK-49F and HK2 cells. Intraperitoneal injection or renal injection of remdesivir attenuated renal fibrosis of UUO kidneys. Renal and liver function were not changed in remdesivir treated UUO mice. Remdesivir can not be detected, but two remdesivir metabolites were detected after injection. Conclusion: Remdesivir inhibits renal fibrosis in obstructed kidneys.was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission.Remdesivir (Product name GS-5734; Cat. No. CSN19703) was purchased from CSNpharm (Chicago, Illinois, USA) and dissolved in DMSO as a 50mg/ml stock, which was further diluted into normal saline by sonication as a working solution.0.04% typan blue dye (A601140, Sangon, Shanghai, China) was added into vehicle or remdisivir working solution to monitor the injection process. 50 μ L of vehicle or remdesivir (1mg/mL) was injected retrogradely once into the left kidney via the ureter.Right after the injection, unilateral ureteral obstruction was performed. Cell cultureHK2 renal proximal tubular epithelial cells were obtained from the Cell Bank of Shanghai Institute of Biological Sciences (Chinese Academy of Science). NRK-49F rat kidney interstitial fibroblast cells were purchased from National Infrastructure of Cell Line Resource, Chinese Academy of Medical Sciences. HK2 and NRK-49F cells were cultured in DMEM/F12 medium containing 10%FBS and 0.5% penicillin and streptomycin in an atmosphere of 5% CO2 and 95% air at 37°C. For Western blotting, HK2 and NRK-49F cells were seeded in 6-well plate to 40-50% confluence, which were starved with DMEM/F12 medium 0.5% fetal bovine serum overnight before the experiment. In the next day, fresh medium containing 0.5% fetal bovine serum was changed, and then cells were exposed to 2.5 ng/ml TGF-β (Peprotech, Rocky Hill, NJ,

Chronic kidney disease (CKD) is a worldwide public health problem that is caused by repeated injuries to the glomerulus or renal tubules. Renal fibrosis commonly accompanies CKD, and it is histologically characterized by excessive deposition of extracellular matrix proteins, such as fibronectin and collagen I, in interstitial areas. Indirect in vivo experimental data suggest that renal asymmetric dimethylarginine (ADMA) exerts antifibrotic activity in CKD. In this study, we aimed to demonstrate that renal ADMA has a direct effect on fibrosis in vivo . Normal saline, ADMA, nonsense control siRNA, Ddah1 siRNA or Ddah2 siRNA was administered into the kidney through the left ureter in a mouse model of unilateral ureteral obstruction (UUO). UUO kidneys were harvested at day 1 or 7. Western blotting was performed to assess the expression of ADMA, DDAH1 and DDAH2 and the expression of fibrotic markers, such as fibronectin, collagen I, α‐smooth muscle actin, phosphorylation of Smad3 and connective tissue growth factor. Masson’s trichrome staining was used to further evaluate renal fibrosis. We observed that intrarenal administration of ADMA increased the renal accumulation of ADMA and attenuated renal fibrosis at days 1 and 7. Knockdown of Ddah1 or Ddah2 increased the amount of ADMA in UUO kidneys and inhibited the expression of fibrotic proteins at days 1 and 7, which was further confirmed by Masson’s staining. Thus, our in vivo data suggest that renal ADMA exerts direct antifibrotic effects in a mouse model of UUO.

Mammalian protein arginine methyltransferase 3 (PRMT3) catalyzes the monomethylation and dimethylation of the arginine residues of proteins. The role of PRMT3 in renal fibrosis is currently unknown. We aimed to study the role of PRMT3 in renal fibrosis and explored its underlying mechanisms. Quantitative PCR analysis and Western blotting analysis showed that the expression of PRMT3 was up-regulated in unilateral ureteral obstruction (UUO) mouse kidneys. Knockout of Prmt3 gene enhanced interstitial fibrosis in UUO kidneys as shown by Masson staining and Western blotting analysis the expression of pro-fibrotic markers. The production of asymmetric dimethylarginine (ADMA) was increased in wide type UUO kidneys but not further increased in Prmt3 knockout UUO kidneys. Administration of exogeneous ADMA in UUO kidneys blocked the enhanced renal interstitial fibrosis in Prmt3 mutant mice. Moreover, genetic deletion of Prmt3 gene increased blood urea nitrogen levels and renal deposition of collagen in folic acid injected mice. We conclude that PRMT3 inhibits renal tubulointerstitial fibrosis through elevating renal ADMA levels.

In order to improve the quality of railway passenger service, the quality of railway passenger service is investigated through field investigation and questionnaire survey, the evaluation index system of railway passenger service quality is established, and the Delphi method is used to screen important service quality evaluation indicators, The model of railway passenger service quality evaluation is established by Delphi method and analytic hierarchy process based on passenger perception, the top five indicators in the weight ranking in the station service quality evaluation index system can show the importance of the station environment in improving the quality of passenger service. On this basis, 1088 valid questionnaires on the addition of lifting stools in station waiting halls were analyzed. The results show that most passengers are concerned about the comfort of the renovated seats and the safety of luggage storage, and the innovative design of the lifting stool greatly improves the space utilization of the waiting hall when improving the railway passenger service.