Transforming growth factor-β1 (TGF-β1) has been shown to modulate both cell proliferation and the synthesis of extracellular matrix by vascular cells. This study was aimed to establish the temporal correlation between TGF-β1 expression, the expression of the extracellular matrix protein fibronectin, and plaque development during atherogenesis of hypercholesterolemic rabbits. New Zealand White rabbits were fed with 2% cholesterol-supplemented chow for 1 week, 2 weeks, 3 weeks or 6 weeks. TGF-β1 mRNA and protein expression was examined in serial sections of aorta by in situ hybridization and immunohistochemistry. Fibronectin expression was examined by immunohistochemistry. In the control and 1-week feeding group, the expression of TGF-β1 mRNA and protein was not apparent. In 2-week feeding group, intimal thickening was detected in which TGF-β1 mRNA and protein were not clearly observed, either. The 3-week and 6-week feeding groups exhibited fatty streaks in which TGF-β1 mRNA and protein expression markedly increased as feeding proceeded. Cell type-specific staining indicated that TGF-β1 was expressed by macrophages as well as smooth muscle cells of the fatty streaks. Immunostaining of fibronectin detected low expression levels in control, 1-week and 2-week feeding groups with pronounced upregulation in the thickened intima and the proximal media in 3-week and 6-week feeding groups. The results implicate a role for TGF-β1 in modulating fatty streak formation and the synthesis of extracellular protein fibronectin during plaque development.
|Number of pages||8|
|Journal||Histology and Histopathology|
|Publication status||Published - 2000 Apr|
All Science Journal Classification (ASJC) codes
- Pathology and Forensic Medicine
- Cell Biology