Original Article

Transient expression of cellular retinol-binding protein-1 during cardiac repair after myocardial infarction YU, Mengyue, et al. Retinoic acid (RA) is a vitamin A derivative that exerts pleiotropic biological effects. Intracellular transport and metabolism of RA are regulated by cellular retinol-binding proteins (CRBP). CRBP-1 is transiently expressed in granulation tissue fibroblasts during wound healing; however, its role in cardiac remodeling remains unknown. A rat myocardial infarction (MI) model was established by ligation of the left coronary artery, and hearts were obtained at 3, 6, 15, 30 and 45 days after operation. Heart sections were examined immunohistochemically using anti-vimentin, anti-α-smooth muscle actin (α-SMA), anti-matrix metalloproteinase (MMP)-2, anti-MMP-9 and anti-CRBP-1 antibodies. Infarction involved 48.8 ± 3.6 % of the left ventricle and was followed by an important cardiac remodeling. Vimentin-positive fibroblastic cells including α-SMA-positive myofibroblasts expressed CRBP-1 at 3-, 6-, and 15-days after MI. Expression of CRBP-1 reached a maximum at 6-days after infarction. Thereafter, CRBP-1 expression was dramatically decreased, showing a similar tendency to MMP expression. Human heart specimens of individuals [...] YU, Mengyue, et al. Transient expression of cellular retinol-binding protein-1 during cardia