Increased expression of biglycan mRNA in pressure-overloaded rat heart

Biglycan mRNA expression in rat myocardium after abdominal aortic banding w ith renal ischemia was examined. The Northern blot analysis demonstrated th at expression of biglycan mRNA in the pressure-overloaded hearts on days 2, 7, 14 and 28 was 2.88 +/-0.89, 2.32 +/-0.49, 2.17 +/-0.57 and 1.81 +/-0.46 -fold higher, respectively, than that in the sham-operated hearts. In situ hybridization showed an increased density of biglycan mRNA signal-positive cells in the pressure-overloaded hearts. The cells with positive signals we re spindle-shaped mesenchymal cells in the myocardial interstitium. A marke d increase in biglycan mRNA signal expression was also observed in endothel ial cells and smooth muscle cells of the thickened myocardial capillary wal l. These results demonstrated an increase in biglycan mRNA in the pressure- overloaded heart in mesenchymal cells in the myocardial interstitium, and i n endothelial and smooth muscle cells of the capillaries, indicating that b iglycan contributes to the ventricular and vascular remodeling in response to pressure overload.