Intermedin attenuates renal fibrosis by induction of heme oxygenase-1 in rats with unilateral ureteral obstruction

Abstract Background Intermedin [IMD, adrenomedullin-2 (ADM-2)] attenuates renal fibrosis by inhibition of oxidative stress. However, the precise mechanisms remain unknown. Heme oxygenase-1 (HO-1), an antioxidant agent, is associated with antifibrogenic effects. ADM is known to induce HO-1. Whether I...

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Main Authors: Xi Qiao, Lihua Wang, Yanhong Wang, Xiaole Su, Yufeng Qiao, Yun Fan, Zhiqiang Peng
Format: Article
Language:English
Published: BioMed Central 2017-07-01
Series:BMC Nephrology
Subjects:
Online Access:http://link.springer.com/article/10.1186/s12882-017-0659-6
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spelling doaj-art-9439a842f9584e28a6fa76e85dc07dc12018-08-20T17:23:04ZengBioMed CentralBMC Nephrology1471-23692017-07-0118111110.1186/s12882-017-0659-6Intermedin attenuates renal fibrosis by induction of heme oxygenase-1 in rats with unilateral ureteral obstructionXi Qiao0Lihua Wang1Yanhong Wang2Xiaole Su3Yufeng Qiao4Yun Fan5Zhiqiang Peng6Department of Nephrology, Second Hospital of Shanxi Medical University, Shanxi Kidney Disease InstituteDepartment of Nephrology, Second Hospital of Shanxi Medical University, Shanxi Kidney Disease InstituteDepartment of Microbiology and Immunology, Shanxi Medical UniversityDepartment of Nephrology, Second Hospital of Shanxi Medical University, Shanxi Kidney Disease InstituteDepartment of Nephrology, Second Hospital of Shanxi Medical University, Shanxi Kidney Disease InstituteDepartment of Nephrology, Second Hospital of Shanxi Medical University, Shanxi Kidney Disease InstituteDepartment of Nephrology, Second Hospital of Shanxi Medical University, Shanxi Kidney Disease InstituteAbstract Background Intermedin [IMD, adrenomedullin-2 (ADM-2)] attenuates renal fibrosis by inhibition of oxidative stress. However, the precise mechanisms remain unknown. Heme oxygenase-1 (HO-1), an antioxidant agent, is associated with antifibrogenic effects. ADM is known to induce HO-1. Whether IMD has any effect on HO-1 is unclear. Herein, we determined whether the antifibrotic properties of IMD are mediated by induction of HO-1. Methods Renal fibrosis was induced by unilateral ureteral obstruction (UUO) performed on male Wistar rats. Rat proximal tubular epithelial cell line (NRK-52E) was exposed to rhTGF-β1 (10 ng/ml) to establish an in vitro model of epithelial-mesenchymal transition (EMT). IMD was over-expressed in vivo and in vitro using the vector pcDNA3.1-IMD. Zinc protoporphyrin (ZnPP) was used to block HO-1 enzymatic activity. IMD effects on HO-1 expression in the obstructed kidney of UUO rat and in TGF-β1-stimulated NRK-52E were analyzed by real-time RT-PCR, Western blotting or immunohistochemistry. HO activity in the obstructed kidney, contralateral kidney of UUO rat and NRK-52E was examined by measuring bilirubin production. Renal fibrosis was determined by Masson trichrome staining and collagen I expression. Macrophage infiltration and IL-6 expression were evaluated using immunohistochemical analysis. In vivo and in vitro EMT was assessed by measuring α-smooth muscle actin (α-SMA) and E-cadherin expression using Western blotting or immunofluorescence, respectively. Results HO-1 expression and HO activity were increased in IMD-treated UUO kidneys or NRK-52E. The obstructed kidneys of UUO rats demonstrated significant interstitial fibrosis on day 7 after operation. In contrast, kidneys that were treated with IMD gene transfer exhibited minimal interstitial fibrosis. The obstructed kidneys of UUO rats also had greater macrophage infiltration and IL-6 expression. IMD restrained infiltration of macrophages and expression of IL-6 in UUO kidneys. The degree of EMT was extensive in obstructed kidneys of UUO rats as indicated by decreased expression of E-cadherin and increased expression of α-SMA. In vitro studies using NRK-52E confirmed these observations. EMT was suppressed by IMD gene delivery. However, all of the above beneficial effects of IMD were eliminated by ZnPP, an inhibitor of HO enzyme activity. Conclusion This study demonstrates that IMD attenuates renal fibrosis by induction of HO-1.http://link.springer.com/article/10.1186/s12882-017-0659-6IntermedinRenalFibrosisReactive oxygen speciesHeme oxygenase-1
institution Open Data Bank
collection Open Access Journals
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language English
format Article
author Xi Qiao
Lihua Wang
Yanhong Wang
Xiaole Su
Yufeng Qiao
Yun Fan
Zhiqiang Peng
spellingShingle Xi Qiao
Lihua Wang
Yanhong Wang
Xiaole Su
Yufeng Qiao
Yun Fan
Zhiqiang Peng
Intermedin attenuates renal fibrosis by induction of heme oxygenase-1 in rats with unilateral ureteral obstruction
BMC Nephrology
Intermedin
Renal
Fibrosis
Reactive oxygen species
Heme oxygenase-1
author_facet Xi Qiao
Lihua Wang
Yanhong Wang
Xiaole Su
Yufeng Qiao
Yun Fan
Zhiqiang Peng
author_sort Xi Qiao
title Intermedin attenuates renal fibrosis by induction of heme oxygenase-1 in rats with unilateral ureteral obstruction
title_short Intermedin attenuates renal fibrosis by induction of heme oxygenase-1 in rats with unilateral ureteral obstruction
title_full Intermedin attenuates renal fibrosis by induction of heme oxygenase-1 in rats with unilateral ureteral obstruction
title_fullStr Intermedin attenuates renal fibrosis by induction of heme oxygenase-1 in rats with unilateral ureteral obstruction
title_full_unstemmed Intermedin attenuates renal fibrosis by induction of heme oxygenase-1 in rats with unilateral ureteral obstruction
title_sort intermedin attenuates renal fibrosis by induction of heme oxygenase-1 in rats with unilateral ureteral obstruction
publisher BioMed Central
series BMC Nephrology
issn 1471-2369
publishDate 2017-07-01
description Abstract Background Intermedin [IMD, adrenomedullin-2 (ADM-2)] attenuates renal fibrosis by inhibition of oxidative stress. However, the precise mechanisms remain unknown. Heme oxygenase-1 (HO-1), an antioxidant agent, is associated with antifibrogenic effects. ADM is known to induce HO-1. Whether IMD has any effect on HO-1 is unclear. Herein, we determined whether the antifibrotic properties of IMD are mediated by induction of HO-1. Methods Renal fibrosis was induced by unilateral ureteral obstruction (UUO) performed on male Wistar rats. Rat proximal tubular epithelial cell line (NRK-52E) was exposed to rhTGF-β1 (10 ng/ml) to establish an in vitro model of epithelial-mesenchymal transition (EMT). IMD was over-expressed in vivo and in vitro using the vector pcDNA3.1-IMD. Zinc protoporphyrin (ZnPP) was used to block HO-1 enzymatic activity. IMD effects on HO-1 expression in the obstructed kidney of UUO rat and in TGF-β1-stimulated NRK-52E were analyzed by real-time RT-PCR, Western blotting or immunohistochemistry. HO activity in the obstructed kidney, contralateral kidney of UUO rat and NRK-52E was examined by measuring bilirubin production. Renal fibrosis was determined by Masson trichrome staining and collagen I expression. Macrophage infiltration and IL-6 expression were evaluated using immunohistochemical analysis. In vivo and in vitro EMT was assessed by measuring α-smooth muscle actin (α-SMA) and E-cadherin expression using Western blotting or immunofluorescence, respectively. Results HO-1 expression and HO activity were increased in IMD-treated UUO kidneys or NRK-52E. The obstructed kidneys of UUO rats demonstrated significant interstitial fibrosis on day 7 after operation. In contrast, kidneys that were treated with IMD gene transfer exhibited minimal interstitial fibrosis. The obstructed kidneys of UUO rats also had greater macrophage infiltration and IL-6 expression. IMD restrained infiltration of macrophages and expression of IL-6 in UUO kidneys. The degree of EMT was extensive in obstructed kidneys of UUO rats as indicated by decreased expression of E-cadherin and increased expression of α-SMA. In vitro studies using NRK-52E confirmed these observations. EMT was suppressed by IMD gene delivery. However, all of the above beneficial effects of IMD were eliminated by ZnPP, an inhibitor of HO enzyme activity. Conclusion This study demonstrates that IMD attenuates renal fibrosis by induction of HO-1.
topic Intermedin
Renal
Fibrosis
Reactive oxygen species
Heme oxygenase-1
url http://link.springer.com/article/10.1186/s12882-017-0659-6
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