Flavopiridol inhibits TGF-β-stimulated biglycan synthesis by blocking linker region phosphorylation and nuclear translocation of Smad2

Transforming Growth Factor (TGF) β is a pleiotropic growth factor implicated in the development of atherosclerosis for its role in mediating glycosaminoglycan (GAG) chain hyperelongation on the proteoglycan biglycan, a phenomenon that leads to increased binding of atherogenic lipoproteins in the wal...

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Main Authors:	Rostam, Muhamad Ashraf, Shajimoon, Aravindra, Kamato, Danielle, Mitra, Partha, Piva, Terence J., Cao, Yingnan, Zheng, Wenhua, Osman, Narin, Little, Peter J.
Format:	Article
Language:	English English
Published:	American Society for Pharmacology and Experimental Therapeutics 2018
Subjects:	RM Therapeutics. Pharmacology
Online Access:	http://irep.iium.edu.my/62174/ http://irep.iium.edu.my/62174/ http://irep.iium.edu.my/62174/ http://irep.iium.edu.my/62174/7/62174_Flavopiridol%20Inhibits%20TGF-%CE%B2-Stimulated%20Biglycan_article.pdf http://irep.iium.edu.my/62174/8/62174_Flavopiridol%20Inhibits%20TGF-%CE%B2-Stimulated%20Biglycan_scopus.pdf

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spelling	iium-621742019-01-30T03:12:53Z http://irep.iium.edu.my/62174/ Flavopiridol inhibits TGF-β-stimulated biglycan synthesis by blocking linker region phosphorylation and nuclear translocation of Smad2 Rostam, Muhamad Ashraf Shajimoon, Aravindra Kamato, Danielle Mitra, Partha Piva, Terence J. Cao, Yingnan Zheng, Wenhua Osman, Narin Little, Peter J. RM Therapeutics. Pharmacology Transforming Growth Factor (TGF) β is a pleiotropic growth factor implicated in the development of atherosclerosis for its role in mediating glycosaminoglycan (GAG) chain hyperelongation on the proteoglycan biglycan, a phenomenon that leads to increased binding of atherogenic lipoproteins in the wall of blood vessels. TGF-β signalling pathway components leading to the modification of GAG chains on biglcyan are therefore potential targets for the treatment of atherosclerosis. Phosphorylation of the transcription factor Smad has emerged as a critical step in the signalling pathways that control the synthesis of biglycan, both the core protein and the GAG chains. We have previously shown that flavopiridol, a well known cyclin dependent kinase (CDK) inhibitor inhibited biglycan synthesis. We have used flavopiridol to study the role of linker region phosphorylation in the TGF-β-stimulated synthesis of biglycan. We used radiosulfate incorporation and SDS PAGE to assess proteoglycan synthesis; RT PCR to assess gene expression and chromatin immunoprecipitation (ChIP) to assess the binding of phosphorylated Smads to the promoter region of GAG synthesis genes. Flavopiridol blocked TGF-β-stimulated synthesis of mRNA for the GAG synthesizing enzymes, chondroitin 4-sulfotransferase (C4ST-1), chondroitin sulfate synthase-1 (ChSy-1), and xylosyltransferase-1 (XT-1); as well as biglycan core protein mRNA and protein expression. The incorporation of radiosulfate into proteoglycans stimulated by TGF-β as well as GAG hyperelongation were also blocked by flavopiridol. Flavopiridol blocked TGF-β-stimulated Smad2 phosphorylation at both the serine triplet and the isolated threonine residue in the linker region. The binding of polyphosphorylated Smad to the promoter region of the C4ST-1 and ChSy-1 genes was stimulated by TGF-β and this response was blocked by flavopiridol demonstrating that linker region phosphorylated Smad can pass to the nucleus and positively regulate transcription. These results demonstrate the validity of the kinases, which phosphorylate the Smad linker region as potential target(s) for the development of a therapeutic agent to prevent atherosclerosis. American Society for Pharmacology and Experimental Therapeutics 2018-04 Article PeerReviewed application/pdf en http://irep.iium.edu.my/62174/7/62174_Flavopiridol%20Inhibits%20TGF-%CE%B2-Stimulated%20Biglycan_article.pdf application/pdf en http://irep.iium.edu.my/62174/8/62174_Flavopiridol%20Inhibits%20TGF-%CE%B2-Stimulated%20Biglycan_scopus.pdf Rostam, Muhamad Ashraf and Shajimoon, Aravindra and Kamato, Danielle and Mitra, Partha and Piva, Terence J. and Cao, Yingnan and Zheng, Wenhua and Osman, Narin and Little, Peter J. (2018) Flavopiridol inhibits TGF-β-stimulated biglycan synthesis by blocking linker region phosphorylation and nuclear translocation of Smad2. Journal of Pharmacology and Experimental Therapeutics, 365 (1). pp. 156-164. ISSN 0022-3565 E-ISSN 1521-0103 http://jpet.aspetjournals.org/content/early/2018/02/09/jpet.117.244483.long 10.1124/jpet.117.244483
repository_type	Digital Repository
institution_category	Local University
institution	International Islamic University Malaysia
building	IIUM Repository
collection	Online Access
language	English English
topic	RM Therapeutics. Pharmacology
spellingShingle	RM Therapeutics. Pharmacology Rostam, Muhamad Ashraf Shajimoon, Aravindra Kamato, Danielle Mitra, Partha Piva, Terence J. Cao, Yingnan Zheng, Wenhua Osman, Narin Little, Peter J. Flavopiridol inhibits TGF-β-stimulated biglycan synthesis by blocking linker region phosphorylation and nuclear translocation of Smad2
description	Transforming Growth Factor (TGF) β is a pleiotropic growth factor implicated in the development of atherosclerosis for its role in mediating glycosaminoglycan (GAG) chain hyperelongation on the proteoglycan biglycan, a phenomenon that leads to increased binding of atherogenic lipoproteins in the wall of blood vessels. TGF-β signalling pathway components leading to the modification of GAG chains on biglcyan are therefore potential targets for the treatment of atherosclerosis. Phosphorylation of the transcription factor Smad has emerged as a critical step in the signalling pathways that control the synthesis of biglycan, both the core protein and the GAG chains. We have previously shown that flavopiridol, a well known cyclin dependent kinase (CDK) inhibitor inhibited biglycan synthesis. We have used flavopiridol to study the role of linker region phosphorylation in the TGF-β-stimulated synthesis of biglycan. We used radiosulfate incorporation and SDS PAGE to assess proteoglycan synthesis; RT PCR to assess gene expression and chromatin immunoprecipitation (ChIP) to assess the binding of phosphorylated Smads to the promoter region of GAG synthesis genes. Flavopiridol blocked TGF-β-stimulated synthesis of mRNA for the GAG synthesizing enzymes, chondroitin 4-sulfotransferase (C4ST-1), chondroitin sulfate synthase-1 (ChSy-1), and xylosyltransferase-1 (XT-1); as well as biglycan core protein mRNA and protein expression. The incorporation of radiosulfate into proteoglycans stimulated by TGF-β as well as GAG hyperelongation were also blocked by flavopiridol. Flavopiridol blocked TGF-β-stimulated Smad2 phosphorylation at both the serine triplet and the isolated threonine residue in the linker region. The binding of polyphosphorylated Smad to the promoter region of the C4ST-1 and ChSy-1 genes was stimulated by TGF-β and this response was blocked by flavopiridol demonstrating that linker region phosphorylated Smad can pass to the nucleus and positively regulate transcription. These results demonstrate the validity of the kinases, which phosphorylate the Smad linker region as potential target(s) for the development of a therapeutic agent to prevent atherosclerosis.
format	Article
author	Rostam, Muhamad Ashraf Shajimoon, Aravindra Kamato, Danielle Mitra, Partha Piva, Terence J. Cao, Yingnan Zheng, Wenhua Osman, Narin Little, Peter J.
author_facet	Rostam, Muhamad Ashraf Shajimoon, Aravindra Kamato, Danielle Mitra, Partha Piva, Terence J. Cao, Yingnan Zheng, Wenhua Osman, Narin Little, Peter J.
author_sort	Rostam, Muhamad Ashraf
title	Flavopiridol inhibits TGF-β-stimulated biglycan synthesis by blocking linker region phosphorylation and nuclear translocation of Smad2
title_short	Flavopiridol inhibits TGF-β-stimulated biglycan synthesis by blocking linker region phosphorylation and nuclear translocation of Smad2
title_full	Flavopiridol inhibits TGF-β-stimulated biglycan synthesis by blocking linker region phosphorylation and nuclear translocation of Smad2
title_fullStr	Flavopiridol inhibits TGF-β-stimulated biglycan synthesis by blocking linker region phosphorylation and nuclear translocation of Smad2
title_full_unstemmed	Flavopiridol inhibits TGF-β-stimulated biglycan synthesis by blocking linker region phosphorylation and nuclear translocation of Smad2
title_sort	flavopiridol inhibits tgf-β-stimulated biglycan synthesis by blocking linker region phosphorylation and nuclear translocation of smad2
publisher	American Society for Pharmacology and Experimental Therapeutics
publishDate	2018
url	http://irep.iium.edu.my/62174/ http://irep.iium.edu.my/62174/ http://irep.iium.edu.my/62174/ http://irep.iium.edu.my/62174/7/62174_Flavopiridol%20Inhibits%20TGF-%CE%B2-Stimulated%20Biglycan_article.pdf http://irep.iium.edu.my/62174/8/62174_Flavopiridol%20Inhibits%20TGF-%CE%B2-Stimulated%20Biglycan_scopus.pdf
first_indexed	2023-09-18T21:28:09Z
last_indexed	2023-09-18T21:28:09Z
_version_	1777412330735271936

Flavopiridol inhibits TGF-β-stimulated biglycan synthesis by blocking linker region phosphorylation and nuclear translocation of Smad2

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