Connective tissue growth factor expression after angiotensin II exposure is dependent on transforming growth factor-β signaling via the canonical Smad-dependent pathway in hypertensive induced myocardial fibrosis
Introduction: Transforming growth factor-β (TGF-β) and connective tissue growth factor (CTGF) are often described as the initial pro-fibrotic mediators upregulated early in fibrosis models dependent on angiotensin II (Ang-II). In the present study, we explore the mechanistic link between TGF-β and C...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
SAGE Publications
2018-03-01
|
| Series: | Journal of the Renin-Angiotensin-Aldosterone System |
| Online Access: | https://doi.org/10.1177/1470320318759358 |
| _version_ | 1797284650376232960 |
|---|---|
| author | Chloe Kok Sum Wong Alec Falkenham Tanya Myers Jean-Francois Légaré |
| author_facet | Chloe Kok Sum Wong Alec Falkenham Tanya Myers Jean-Francois Légaré |
| author_sort | Chloe Kok Sum Wong |
| collection | DOAJ |
| description | Introduction: Transforming growth factor-β (TGF-β) and connective tissue growth factor (CTGF) are often described as the initial pro-fibrotic mediators upregulated early in fibrosis models dependent on angiotensin II (Ang-II). In the present study, we explore the mechanistic link between TGF-β and CTGF expression by using a novel TGF-β trap. Materials and methods: NIH/3T3 fibroblasts were subjected to TGF-β with or without TGF-β trap or 1D11 antibody, CTGF or CTGF plus TGF-β for six or 24 hours, and then used for quantitative real-time polymerase chain reaction (qRT-PCR) or immunocytochemistry. Male C57BL/6 mice were infused with Ang-II and randomly assigned TGF-β trap for six or 24 hours. Hearts were harvested for histological analyses, qRT-PCR and western blotting. Results: Exogenous TGF-β-induced fibroblasts resulted in significant upregulation of CTGF, TGF-β and type I collagen transcript levels in vitro. Additionally, TGF-β promoted the differentiation of fibroblasts into α-SMA + myofibroblasts. CTGF expression was reduced by the addition of TGF-β trap or neutralizing antibody, confirming that its expression is dependent on TGF-β signaling. In contrast, exogenous CTGF did not appear to have an effect on fibroblast production of pro-fibrotic transcripts or fibroblast differentiation. Ang-II infusion in vivo led to a significant increase in TGF-β and CTGF mRNA expression at six and 24 hours with corresponding changes in Smad2 phosphorylation (pSmad2), indicative of increased TGF-β signaling. Ang-II animals that received the TGF-β trap demonstrated reduced CTGF mRNA levels and pSmad2 at six hours, suggesting that early CTGF expression is dependent on TGF-β signaling. Conclusions: We demonstrated that CTGF expression is dependent on TGF-β signaling both in vitro and in vivo in a model of myocardial fibrosis. This also suggests that early myocardial CTGF mRNA expression (six hours) after Ang-II exposure is likely dependent on latent TGF-β activation via the canonical Smad-dependent pathway in resident cardiac cells. |
| first_indexed | 2024-03-07T17:51:22Z |
| format | Article |
| id | doaj.art-f3342ab7397742b293bb06a6eb5f61be |
| institution | Directory Open Access Journal |
| issn | 1752-8976 |
| language | English |
| last_indexed | 2024-03-07T17:51:22Z |
| publishDate | 2018-03-01 |
| publisher | SAGE Publications |
| record_format | Article |
| series | Journal of the Renin-Angiotensin-Aldosterone System |
| spelling | doaj.art-f3342ab7397742b293bb06a6eb5f61be2024-03-02T14:04:01ZengSAGE PublicationsJournal of the Renin-Angiotensin-Aldosterone System1752-89762018-03-011910.1177/1470320318759358Connective tissue growth factor expression after angiotensin II exposure is dependent on transforming growth factor-β signaling via the canonical Smad-dependent pathway in hypertensive induced myocardial fibrosisChloe Kok Sum Wong0Alec Falkenham1Tanya Myers2Jean-Francois Légaré3Department of Pathology, Dalhousie University, Halifax, NS, CanadaDepartment of Pathology, Dalhousie University, Halifax, NS, CanadaDepartment of Surgery, Dalhousie University, Halifax, NS, CanadaCardiovascular Research New Brunswick, New Brunswick Heart Centre, Saint John Regional Hospital, Saint John, New Brunswick, CanadaIntroduction: Transforming growth factor-β (TGF-β) and connective tissue growth factor (CTGF) are often described as the initial pro-fibrotic mediators upregulated early in fibrosis models dependent on angiotensin II (Ang-II). In the present study, we explore the mechanistic link between TGF-β and CTGF expression by using a novel TGF-β trap. Materials and methods: NIH/3T3 fibroblasts were subjected to TGF-β with or without TGF-β trap or 1D11 antibody, CTGF or CTGF plus TGF-β for six or 24 hours, and then used for quantitative real-time polymerase chain reaction (qRT-PCR) or immunocytochemistry. Male C57BL/6 mice were infused with Ang-II and randomly assigned TGF-β trap for six or 24 hours. Hearts were harvested for histological analyses, qRT-PCR and western blotting. Results: Exogenous TGF-β-induced fibroblasts resulted in significant upregulation of CTGF, TGF-β and type I collagen transcript levels in vitro. Additionally, TGF-β promoted the differentiation of fibroblasts into α-SMA + myofibroblasts. CTGF expression was reduced by the addition of TGF-β trap or neutralizing antibody, confirming that its expression is dependent on TGF-β signaling. In contrast, exogenous CTGF did not appear to have an effect on fibroblast production of pro-fibrotic transcripts or fibroblast differentiation. Ang-II infusion in vivo led to a significant increase in TGF-β and CTGF mRNA expression at six and 24 hours with corresponding changes in Smad2 phosphorylation (pSmad2), indicative of increased TGF-β signaling. Ang-II animals that received the TGF-β trap demonstrated reduced CTGF mRNA levels and pSmad2 at six hours, suggesting that early CTGF expression is dependent on TGF-β signaling. Conclusions: We demonstrated that CTGF expression is dependent on TGF-β signaling both in vitro and in vivo in a model of myocardial fibrosis. This also suggests that early myocardial CTGF mRNA expression (six hours) after Ang-II exposure is likely dependent on latent TGF-β activation via the canonical Smad-dependent pathway in resident cardiac cells.https://doi.org/10.1177/1470320318759358 |
| spellingShingle | Chloe Kok Sum Wong Alec Falkenham Tanya Myers Jean-Francois Légaré Connective tissue growth factor expression after angiotensin II exposure is dependent on transforming growth factor-β signaling via the canonical Smad-dependent pathway in hypertensive induced myocardial fibrosis Journal of the Renin-Angiotensin-Aldosterone System |
| title | Connective tissue growth factor expression after angiotensin II exposure is dependent on transforming growth factor-β signaling via the canonical Smad-dependent pathway in hypertensive induced myocardial fibrosis |
| title_full | Connective tissue growth factor expression after angiotensin II exposure is dependent on transforming growth factor-β signaling via the canonical Smad-dependent pathway in hypertensive induced myocardial fibrosis |
| title_fullStr | Connective tissue growth factor expression after angiotensin II exposure is dependent on transforming growth factor-β signaling via the canonical Smad-dependent pathway in hypertensive induced myocardial fibrosis |
| title_full_unstemmed | Connective tissue growth factor expression after angiotensin II exposure is dependent on transforming growth factor-β signaling via the canonical Smad-dependent pathway in hypertensive induced myocardial fibrosis |
| title_short | Connective tissue growth factor expression after angiotensin II exposure is dependent on transforming growth factor-β signaling via the canonical Smad-dependent pathway in hypertensive induced myocardial fibrosis |
| title_sort | connective tissue growth factor expression after angiotensin ii exposure is dependent on transforming growth factor β signaling via the canonical smad dependent pathway in hypertensive induced myocardial fibrosis |
| url | https://doi.org/10.1177/1470320318759358 |
| work_keys_str_mv | AT chloekoksumwong connectivetissuegrowthfactorexpressionafterangiotensiniiexposureisdependentontransforminggrowthfactorbsignalingviathecanonicalsmaddependentpathwayinhypertensiveinducedmyocardialfibrosis AT alecfalkenham connectivetissuegrowthfactorexpressionafterangiotensiniiexposureisdependentontransforminggrowthfactorbsignalingviathecanonicalsmaddependentpathwayinhypertensiveinducedmyocardialfibrosis AT tanyamyers connectivetissuegrowthfactorexpressionafterangiotensiniiexposureisdependentontransforminggrowthfactorbsignalingviathecanonicalsmaddependentpathwayinhypertensiveinducedmyocardialfibrosis AT jeanfrancoislegare connectivetissuegrowthfactorexpressionafterangiotensiniiexposureisdependentontransforminggrowthfactorbsignalingviathecanonicalsmaddependentpathwayinhypertensiveinducedmyocardialfibrosis |