1, 25-(OH)2-VitD3 attenuates renal tubulointerstitial fibrosis in diabetic kidney disease by inhibiting Snail1-SMAD3/SMAD4 complex formation.
- Author:
Chengchong HUANG
1
;
Rong DONG
2
,
3
,
4
;
Zhengsheng LI
5
;
Jing YUAN
2
,
6
Author Information
1. The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang 550002, China.
2. Department of Nephrology, Guizhou Provincial People's Hospital
3. NHC Key Laboratory of Pulmonary Immunological Disease, Guiyang 550002
4. College of Medicine, Guizhou University, Guiyang 550025, China.
5. Department of Nephrology, The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang 550001, China.
6. NHC Key Laboratory of Pulmonary Immunological Disease, Guiyang 550002, China. *Corresponding author, E-mail: yuanjinger@126.com.
- Publication Type:Journal Article
- MeSH:
Animals;
Rats;
Cadherins/genetics*;
Diabetes Mellitus/pathology*;
Diabetic Nephropathies/pathology*;
Epithelial-Mesenchymal Transition;
Fibrosis/pathology*;
Glucose/pharmacology*;
Kidney/pathology*;
Rats, Sprague-Dawley;
RNA, Messenger;
RNA, Small Interfering;
Transforming Growth Factor beta1/metabolism*;
Vitamin D/pharmacology*
- From:
Chinese Journal of Cellular and Molecular Immunology
2023;39(4):325-331
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the effect of 1, 25-(OH)2-VitD3 (VitD3) on renal tubuleinterstitial fibrosis in diabetic kidney disease. Methods NRK-52E renal tubular epithelial cells were divided into control group (5.5 mmol/L glucose medium treatment), high glucose group (25 mmol/L glucose medium treatment) and high glucose with added VitD3 group (25 mmol/L glucose medium combined with 10-8 mmol/L VitD3). The mRNA and protein expression of Snail1, SMAD3, SMAD4, α-SMA and E-cadherin in NRK-52E cells were detected by real-time quantitative PCR and Western blot analysis respectively. The expression and localization of Snail1, SMAD3 and SMAD4 were detected by immunofluorescence cytochemical staining. The binding of Snail1 with SMAD3/SMAD4 complex to the promoter of Coxsackie-adenovirus receptor (CAR) was detected by chromatin immunoprecipitation. The interaction among Snail1, SMAD3/SMAD4 and E-cadherin were detected by luciferase assay. Small interfering RNA (siRNA) was used to inhibit the expression of Snail1 and SMAD4, and the expression of mRNA of E-cadherin was detected by real-time quantitative PCR. SD rats were randomly divided into control group, DKD group and VitD3-treated group. DKD model was established by injection of streptozotocin (STZ) in DKD group and VitD3-treated group. After DKD modeling, VitD3-treated group was given VitD3 (60 ng/kg) intragastric administration. Control group and DKD group were given normal saline intragastric administration. In the DKD group and VitD3-treated group, insulin (1-2 U/kg) was injected subcutaneously to control blood glucose for 8 weeks. The mRNA and protein levels of Snail1, SMAD3, SMAD4, α-SMA and E-cadherin in renal tissues were detected by real-time quantitative PCR and Western blot analysis respectively. Immunohistochemistry was used to detect the expression and localization of Snail1, SMAD3, SMAD4, α-SMA and E-cadherin in renal tissue. Results Compared with the control group, the mRNA and protein expressions of Snail1, SMAD3, SMAD4 and α-SMA in NRK-52E cells cultured with high glucose and in DKD renal tissues were up-regulated, while E-cadherin expression was down-regulated. After the intervention of VitD3, the expression levels of Snail1, SMAD3, SMAD4, α-SMA and E-cadherin in the DKD model improved to be close to those in the control group. Chromatin immunoprecipitation showed that Snail1 and SMAD3/SMAD4 bound to CAR promoter IV, while VitD3 prevented Snail1 and SMAD3/SMAD4 from binding to CAR promoter IV. Luciferase assay confirmed the interaction among Snail1, SMAD3/SMAD4 and E-cadherin. After the mRNA of Snail1 and SMAD4 was inhibited by siRNA, the expression of E-cadherin induced by high glucose was up-regulated. Conclusion VitD3 could inhibit the formation of Snail1-SMAD3/SMAD4 complex and alleviate the renal tubulointerstitial fibrosis in DKD.
