Induction of Tenascin-C in Cardiac Myocytes by Mechanical Deformation

doi:10.1074/jbc.274.31.21840

Induction of Tenascin-C in Cardiac Myocytes by Mechanical Deformation

ROLE OF REACTIVE OXYGEN SPECIES*

From the ^‡Cardiovascular Division, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts 02115 and the ^¶Central Research Division, Molecular Sciences Department, Pfizer Inc., Groton, Connecticut 06340

Abstract

Mechanical overload may change cardiac structure through angiotensin II-dependent and angiotensin II-independent mechanisms. We investigated the effects of mechanical strain on the gene expression of tenascin-C, a prominent extracellular molecule in actively remodeling tissues, in neonatal rat cardiac myocytes. Mechanical strain induced tenascin-C mRNA (3.9 ± 0.5-fold, p < 0.01, n = 13) and tenascin-C protein in an amplitude-dependent manner but did not induce secreted protein acidic and rich in cysteine nor fibronectin. RNase protection assay demonstrated that mechanical strain induced all three alternatively spliced isoforms of tenascin-C. An angiotensin II receptor type 1 antagonist inhibited mechanical induction of brain natriuretic peptide but not tenascin-C. Antioxidants such as N-acetyl-l-cysteine, catalase, and 1,2-dihydroxy-benzene-3,5-disulfonate significantly inhibited induction of tenascin-C. Truncated tenascin-C promoter-reporter assays using dominant negative mutants of IκBα and IκB kinase β and electrophoretic mobility shift assays indicated that mechanical strain increases tenascin-C gene transcription by activating nuclear factor-κB through reactive oxygen species. Our findings demonstrate that mechanical strain induces tenascin-C in cardiac myocytes through a nuclear factor-κB-dependent and angiotensin II-independent mechanism. These data also suggest that reactive oxygen species may participate in mechanically induced left ventricular remodeling.

Footnotes

↵* This work was supported in part by a Grant-in-Aid from the American Heart Association and by NHLBI Grant HL-54759 from the National Institutes of Health.The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
↵§ Supported in part by grants from the Uehara Memorial Foundation, the Mochida Memorial Foundation for Medical and Pharmaceutical Research, and the Japan Foundation of Cardiovascular Research.
↵‖ To whom correspondence should be addressed: Cardiovascular Division, Brigham and Women’s Hospital, 75 Francis St., Boston, MA 02115. Tel.: 617-732-7146; Fax: 617-264-5139; E-mail: rtlee@bics.bwh.harvard.edu.
Abbreviations:

AT₁

angiotensin II receptor type 1

NRVM

neonatal rat ventricular myocytes

BNP

brain natriuretic peptide

MAP

mitogen-activated protein

JNK

c-Jun NH₂-terminal kinases

ROS

reactive oxygen species

NF

nuclear factor

HBSS

Hanks’ balanced salt solution

DMEM

Dulbecco’s modified Eagle’s medium

FCS

fetal calf serum

SPARC

secreted protein acidic and rich in cysteine

GAPDH

glyceraldehyde-3-phosphate dehydrogenase

CAT

chloramphenicol acetyltransferase

PDGF-BB

platelet-derived growth factor-BB

IKK

IκB kinase
- Received February 2, 1999.
- Revision received May 27, 1999.
The American Society for Biochemistry and Molecular Biology, Inc.