A novel cultured tissue model of rat aorta: VSMC proliferation mechanism in relationship to atherosclerosis

• Published in: Experimental and molecular pathology 2007-12, Vol.83 (3), p.453-458
• Main Authors: Wang, Caiying, Zhang, Yanlin, Yang, Qin, Yang, Yaan, Gu, Yongping, Wang, Mincheng, Wu, Kaiyun
• Format: Article
• Language: English
• Subjects: Animals; Aorta, Abdominal - anatomy & histology; Atherosclerosis; Atherosclerosis (general aspects, experimental research); Biological and medical sciences; Blood and lymphatic vessels; Cardiology. Vascular system; Cell Proliferation; Endothelin-1; Endothelin-1 - metabolism; Hypertension-related gene-1 (HRG-1); Investigative techniques, diagnostic techniques (general aspects); Male; Medical sciences; Models, Biological; Muscle, Smooth, Vascular - cytology; Muscle, Smooth, Vascular - physiology; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; Phenotype; Rats; Rats, Sprague-Dawley; Smooth muscle 22 alpha (SM22α); Tissue Culture Techniques; VSMC proliferation
• ISSN: 0014-4800; 1096-0945
• DOI: 10.1016/j.yexmp.2007.08.002

Development of a cultured tissue experimental model of rat aorta was explored in order to study mechanism of vascular smooth muscle (VSMC) proliferation. This particular model has potential with regard to amelioration of atherosclerosis and other vascular diseases in comparison to whole animal and cell culture models. The aorta segments of rats were divided into 4 experimental groups: the injured endothelium, injured endothelium plus BQ123, without injured endothelium and without injured endothelium plus BQ123. Each of group was subdivided into a further 2 subgroups and cultured with 20% serum and with serum-free DMEM. Each group cultured in vitro for 5, 8 and 13 days respectively. The control group was not cultured in vitro. Bromodeoxyuridine (BrDU 8 × 10 − 4  mol/l) was added into the cultured medium of all groups, 24 h prior to harvesting. These segments were fixed in 4% paraformaldehyde for paraffin slice used to HE and immunocytochemical staining and other aorta segments were used to detect the expressions of hypertension-related gene-1 (HRG-1) and smooth muscle 22 alpha (SM22α) by RT-PCR. ET-1 content in the supernatant was detected with radioimmunology. Proliferous VSMC can be observed on artery segments cultured in vitro, and conspicuous plaques were developed on model vascular wall cultured for 13 days. Labeled cells increased with an increase in culture time but were not seen in the control group. A greater number of labeled cells were observed in injured endothelium group cultured in 20% serum DMEM. Hyperplasia was inhibited after BQ123 was added into the medium, suggesting that serum and ET-1 are important factors that lead to VSMC proliferation. Expressions of HRG-1 and SM22α were decreased while the aorta segments were cultured in vitro, minimum or even absent mRNA expressions of HRG-1 and SM22α were detected in injured endothelium cultured in 20% serum DMEM and increased in injured endothelium plus BQ123 group cultured. ET-1 content in the supernatant increased in injured endothelium cultured in 20% serum DMEM. These results show that the phenotypic transform and VSMC proliferation on cultured artery segments were related not only to serum culture, but also to ET-1 secreting. ET-1 and serum may be the main factors of contributing to the proliferation and phenotypic transform. This model provides a favorable experimental platform for research into the mechanism of vascular proliferous diseases as well as its prevention and treatment.