Expression of the multifunctional Y-box protein, YB-1, in myofibroblasts of the infarcted rat heart.
Intracellular signaling mechanisms regulating the turnover of alpha-SMA-positive myofibroblasts (myoFbs) at the site of myocardial infarction (MI) are poorly understood. Y-Box (YB)-1, a multifunctional protein, may be involved in regulation of proliferation, migration and apoptosis of myoFbs. Our objective was to study the expression of YB-1 in the infarcted rat heart and its localization in myoFbs. On days 3-28 following MI, we monitored YB-1 expression and its colocalization with alpha-SMA, and proliferation markers PCNA and Ki-67 in infarcted tissue by Western blot, immunohistochemistry, and immunofluorescent double-labeling. YB-1 is barely detectable in normal myocardium. At the infarct site, however, YB-1 is markedly elevated from day 3 post-MI concomitant with the induction of cell proliferation. MyoFbs are the major source of YB-1 and retain it up to day 28 post-MI. We suggest early expression of YB-1 promotes proliferation and migration of myoFbs, whereas prolonged expression may be responsible for scar formation.
Department of Molecular Sciences, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
German
G
Kamalov
Balwantkumar R
BR
Varma
Li
L
Lu
Yao
Y
Sun
Karl T
KT
Weber
Ramareddy V
RV
Guntaka
D000818:Animals; D022762:CCAAT-Enhancer-Binding Proteins / Q000378:metabolism*; D002478:Cells, Cultured; D005347:Fibroblasts / Q000378:metabolism*; D006352:Heart Ventricles / Q000378:metabolism*; D008297:Male; D009203:Myocardial Infarction / Q000378:metabolism*; D051839:NFI Transcription Factors; D051381:Rats; D017207:Rats, Sprague-Dawley; D014018:Tissue Distribution; D014157:Transcription Factors / Q000378:metabolism*; D051840:Y-Box-Binding Protein 1
D022762:CCAAT-Enhancer-Binding Proteins; D051839:NFI Transcription Factors; D014157:Transcription Factors; D051840:Y-Box-Binding Protein 1