Fibroblast expression of the coactivator p300 governs the intensity of profibrotic response to transforming growth factor β

Swati Bhattacharyya, Asish K Ghosh*, Jaspreet Pannu, Yasuji Mori, Shinsuke Takagawa, Guofen Chen, Maria Trojanowska, Anita C. Gilliam, John Varga

*Corresponding author for this work

Research output: Contribution to journalArticle

66 Citations (Scopus)

Abstract

Objective. Transforming growth factor β (TGFβ) induces profibrotic responses in normal fibroblasts, and plays a fundamental role in the pathogenesis of fibrosis in scleroderma (systemic sclerosis [SSc]). The intensity of cellular responses elicited by cytokines is modulated by transcriptional coactivators such as the histone acetylase p300. The objective of these studies was to delineate the physiologic role of p300 in Smad-dependent profibrotic responses elicited by TGFβ. Methods. Ectopic p300 was transiently expressed in normal dermal fibroblasts. Cellular p300 levels were suppressed using p300-specific ribozymes. The regulation of gene expression was examined by transient transfection assays, Northern blotting, and immunoblot analysis. The expression of p300 in normal and scleroderma fibroblasts was evaluated by confocal microscopy and immunoblotting, and p300 levels in skin from mice with experimental scleroderma were assessed by immunohistochemistry. Results. In normal fibroblasts, TGFβ induced an increase in the levels of p300. Forced expression of ectopic p300 in these cells dramatically enhanced the magnitude of TGFβ responses, whereas selective depletion of p300 using ribozyme resulted in abrogation of TGFβ-induced collagen synthesis and promoter activity. Furthermore, TGFβ lost its ability to induce Smad-dependent transcription in p300-depleted fibroblasts. These responses could be fully rescued with ectopic p300. Abrogation of Smad-mediated TGFβ signaling was not due to alterations in the levels or the ligand-dependenf phosphorylation or intracellular trafficking of endogenous Smads. Immunohistochemical analysis demonstrated substantially increased p300 expression in lesional skin from mice with chronic graft-versus-host disease, an animal model of scleroderma. Furthermore, levels of p300 were 2-3-fold higher in cultured fibroblasts derived from SSc patients than in fibroblasts from matched normal controls. Conclusion. These results establish, for the first time, that the coactivator histone acetylase p300, itself a target of TGFβ regulation, is an essential component of the cellular TGFβ signal transduction pathways mediating stimulation of collagen synthesis in fibroblasts. Since the cellular abundance of p300 appears to govern the intensity of profibrotic responses elicited by TGFβ, elevated p300 expression in lesional tissue may contribute to the progression of skin fibrosis in scleroderma.

Original languageEnglish (US)
Pages (from-to)1248-1258
Number of pages11
JournalArthritis and rheumatism
Volume52
Issue number4
DOIs
StatePublished - Apr 1 2005

Fingerprint

Transforming Growth Factors
Fibroblasts
Catalytic RNA
Skin
Systemic Scleroderma
Fibrosis
Collagen
Fibroblast Growth Factors
Gene Expression Regulation
Graft vs Host Disease
Immunoblotting
Confocal Microscopy
Northern Blotting
Transfection
Signal Transduction
Animal Models
Immunohistochemistry
Phosphorylation
Cytokines
Ligands

ASJC Scopus subject areas

  • Immunology and Allergy
  • Rheumatology
  • Immunology
  • Pharmacology (medical)

Cite this

Bhattacharyya, Swati ; Ghosh, Asish K ; Pannu, Jaspreet ; Mori, Yasuji ; Takagawa, Shinsuke ; Chen, Guofen ; Trojanowska, Maria ; Gilliam, Anita C. ; Varga, John. / Fibroblast expression of the coactivator p300 governs the intensity of profibrotic response to transforming growth factor β. In: Arthritis and rheumatism. 2005 ; Vol. 52, No. 4. pp. 1248-1258.
@article{d02c8d0c355b42a89f45b1a7f816db30,
title = "Fibroblast expression of the coactivator p300 governs the intensity of profibrotic response to transforming growth factor β",
abstract = "Objective. Transforming growth factor β (TGFβ) induces profibrotic responses in normal fibroblasts, and plays a fundamental role in the pathogenesis of fibrosis in scleroderma (systemic sclerosis [SSc]). The intensity of cellular responses elicited by cytokines is modulated by transcriptional coactivators such as the histone acetylase p300. The objective of these studies was to delineate the physiologic role of p300 in Smad-dependent profibrotic responses elicited by TGFβ. Methods. Ectopic p300 was transiently expressed in normal dermal fibroblasts. Cellular p300 levels were suppressed using p300-specific ribozymes. The regulation of gene expression was examined by transient transfection assays, Northern blotting, and immunoblot analysis. The expression of p300 in normal and scleroderma fibroblasts was evaluated by confocal microscopy and immunoblotting, and p300 levels in skin from mice with experimental scleroderma were assessed by immunohistochemistry. Results. In normal fibroblasts, TGFβ induced an increase in the levels of p300. Forced expression of ectopic p300 in these cells dramatically enhanced the magnitude of TGFβ responses, whereas selective depletion of p300 using ribozyme resulted in abrogation of TGFβ-induced collagen synthesis and promoter activity. Furthermore, TGFβ lost its ability to induce Smad-dependent transcription in p300-depleted fibroblasts. These responses could be fully rescued with ectopic p300. Abrogation of Smad-mediated TGFβ signaling was not due to alterations in the levels or the ligand-dependenf phosphorylation or intracellular trafficking of endogenous Smads. Immunohistochemical analysis demonstrated substantially increased p300 expression in lesional skin from mice with chronic graft-versus-host disease, an animal model of scleroderma. Furthermore, levels of p300 were 2-3-fold higher in cultured fibroblasts derived from SSc patients than in fibroblasts from matched normal controls. Conclusion. These results establish, for the first time, that the coactivator histone acetylase p300, itself a target of TGFβ regulation, is an essential component of the cellular TGFβ signal transduction pathways mediating stimulation of collagen synthesis in fibroblasts. Since the cellular abundance of p300 appears to govern the intensity of profibrotic responses elicited by TGFβ, elevated p300 expression in lesional tissue may contribute to the progression of skin fibrosis in scleroderma.",
author = "Swati Bhattacharyya and Ghosh, {Asish K} and Jaspreet Pannu and Yasuji Mori and Shinsuke Takagawa and Guofen Chen and Maria Trojanowska and Gilliam, {Anita C.} and John Varga",
year = "2005",
month = "4",
day = "1",
doi = "10.1002/art.20996",
language = "English (US)",
volume = "52",
pages = "1248--1258",
journal = "Arthritis and Rheumatology",
issn = "2326-5191",
publisher = "John Wiley and Sons Ltd",
number = "4",

}

Fibroblast expression of the coactivator p300 governs the intensity of profibrotic response to transforming growth factor β. / Bhattacharyya, Swati; Ghosh, Asish K; Pannu, Jaspreet; Mori, Yasuji; Takagawa, Shinsuke; Chen, Guofen; Trojanowska, Maria; Gilliam, Anita C.; Varga, John.

In: Arthritis and rheumatism, Vol. 52, No. 4, 01.04.2005, p. 1248-1258.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Fibroblast expression of the coactivator p300 governs the intensity of profibrotic response to transforming growth factor β

AU - Bhattacharyya, Swati

AU - Ghosh, Asish K

AU - Pannu, Jaspreet

AU - Mori, Yasuji

AU - Takagawa, Shinsuke

AU - Chen, Guofen

AU - Trojanowska, Maria

AU - Gilliam, Anita C.

AU - Varga, John

PY - 2005/4/1

Y1 - 2005/4/1

N2 - Objective. Transforming growth factor β (TGFβ) induces profibrotic responses in normal fibroblasts, and plays a fundamental role in the pathogenesis of fibrosis in scleroderma (systemic sclerosis [SSc]). The intensity of cellular responses elicited by cytokines is modulated by transcriptional coactivators such as the histone acetylase p300. The objective of these studies was to delineate the physiologic role of p300 in Smad-dependent profibrotic responses elicited by TGFβ. Methods. Ectopic p300 was transiently expressed in normal dermal fibroblasts. Cellular p300 levels were suppressed using p300-specific ribozymes. The regulation of gene expression was examined by transient transfection assays, Northern blotting, and immunoblot analysis. The expression of p300 in normal and scleroderma fibroblasts was evaluated by confocal microscopy and immunoblotting, and p300 levels in skin from mice with experimental scleroderma were assessed by immunohistochemistry. Results. In normal fibroblasts, TGFβ induced an increase in the levels of p300. Forced expression of ectopic p300 in these cells dramatically enhanced the magnitude of TGFβ responses, whereas selective depletion of p300 using ribozyme resulted in abrogation of TGFβ-induced collagen synthesis and promoter activity. Furthermore, TGFβ lost its ability to induce Smad-dependent transcription in p300-depleted fibroblasts. These responses could be fully rescued with ectopic p300. Abrogation of Smad-mediated TGFβ signaling was not due to alterations in the levels or the ligand-dependenf phosphorylation or intracellular trafficking of endogenous Smads. Immunohistochemical analysis demonstrated substantially increased p300 expression in lesional skin from mice with chronic graft-versus-host disease, an animal model of scleroderma. Furthermore, levels of p300 were 2-3-fold higher in cultured fibroblasts derived from SSc patients than in fibroblasts from matched normal controls. Conclusion. These results establish, for the first time, that the coactivator histone acetylase p300, itself a target of TGFβ regulation, is an essential component of the cellular TGFβ signal transduction pathways mediating stimulation of collagen synthesis in fibroblasts. Since the cellular abundance of p300 appears to govern the intensity of profibrotic responses elicited by TGFβ, elevated p300 expression in lesional tissue may contribute to the progression of skin fibrosis in scleroderma.

AB - Objective. Transforming growth factor β (TGFβ) induces profibrotic responses in normal fibroblasts, and plays a fundamental role in the pathogenesis of fibrosis in scleroderma (systemic sclerosis [SSc]). The intensity of cellular responses elicited by cytokines is modulated by transcriptional coactivators such as the histone acetylase p300. The objective of these studies was to delineate the physiologic role of p300 in Smad-dependent profibrotic responses elicited by TGFβ. Methods. Ectopic p300 was transiently expressed in normal dermal fibroblasts. Cellular p300 levels were suppressed using p300-specific ribozymes. The regulation of gene expression was examined by transient transfection assays, Northern blotting, and immunoblot analysis. The expression of p300 in normal and scleroderma fibroblasts was evaluated by confocal microscopy and immunoblotting, and p300 levels in skin from mice with experimental scleroderma were assessed by immunohistochemistry. Results. In normal fibroblasts, TGFβ induced an increase in the levels of p300. Forced expression of ectopic p300 in these cells dramatically enhanced the magnitude of TGFβ responses, whereas selective depletion of p300 using ribozyme resulted in abrogation of TGFβ-induced collagen synthesis and promoter activity. Furthermore, TGFβ lost its ability to induce Smad-dependent transcription in p300-depleted fibroblasts. These responses could be fully rescued with ectopic p300. Abrogation of Smad-mediated TGFβ signaling was not due to alterations in the levels or the ligand-dependenf phosphorylation or intracellular trafficking of endogenous Smads. Immunohistochemical analysis demonstrated substantially increased p300 expression in lesional skin from mice with chronic graft-versus-host disease, an animal model of scleroderma. Furthermore, levels of p300 were 2-3-fold higher in cultured fibroblasts derived from SSc patients than in fibroblasts from matched normal controls. Conclusion. These results establish, for the first time, that the coactivator histone acetylase p300, itself a target of TGFβ regulation, is an essential component of the cellular TGFβ signal transduction pathways mediating stimulation of collagen synthesis in fibroblasts. Since the cellular abundance of p300 appears to govern the intensity of profibrotic responses elicited by TGFβ, elevated p300 expression in lesional tissue may contribute to the progression of skin fibrosis in scleroderma.

UR - http://www.scopus.com/inward/record.url?scp=17244371148&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=17244371148&partnerID=8YFLogxK

U2 - 10.1002/art.20996

DO - 10.1002/art.20996

M3 - Article

C2 - 15818659

AN - SCOPUS:17244371148

VL - 52

SP - 1248

EP - 1258

JO - Arthritis and Rheumatology

JF - Arthritis and Rheumatology

SN - 2326-5191

IS - 4

ER -