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Objective: To investigate whether the number of circulating endothelial progenitor cells (EPCs) correlate with the severity of coronary stenosis in patients with stable coronary artery disease (CAD)., Methods: 80 consecutive patients who underwent coronary angiography (exclusion of acute coronary syndrome and myocardial infarction) were enrolled. Physical examination and blood tests were performed to assess the disease severity and cardiovascular risk factors. Circulating EPCs as measured by the number of CD133/KDR double positive cells were detected by FACS., Results: The number of EPCs inversely correlated with age, creatinine clearance (Ccr) and left ventricular mass index (LVMI) (P = 0.004, 0.015, 0.014 respectively). Patients with hypertension showed significant reduction in number of EPCs compared to those without hypertension (P = 0.004). Moreover, the number of EPCs in patients with coronary artery disease was significantly lower than that of those with normal coronary artery (P < 0.01). EPCs also inversely correlated with angiographic Gensini score (n = 49, r = -0.305, P = 0.039)., Conclusions: In patients with stable CAD, the numbers of circulating EPCs correlate with the severity of CAD as well as cardiovascular risk factors.

Migration of adventitial fibroblasts (AF) is involved in the neointimal formation which is one of the common pathological processes in several vascular diseases. The observation of whether the migratory response of AF from hypertensive animal is different from that of controls may provide an explanation of vascular remodeling in hypertension. We examined whether there is any difference between the migratory activity of AF derived from spontaneously hypertensive rat (SHR) and that from their normotensive counterpart Wistar-Kyoto rats (WKY). In addition, the role of osteopontin (OPN) in cell migration was also examined. Primary cultures of aortic adventitial fibroblasts were derived from SHR and age-matched WKY. Migration of fibroblasts was determined with the Transwell method. The mRNA expression level of OPN was measured by a real-time quantitative PCR. When compared with WKY-derived cells, migration of adventitial fibroblasts from SHR exhibited an increased response when stimulated by 10% serum (cell number per field 35.20+/-5.26 vs 22.2+/-3.27, p<0.05). Chemotaxis induced by 10 ng/ml bFGF showed a similar difference (cell number per field 30.23+/-4.54 vs 19.20+/-4.47, p<0.05). We also found that SHR-derived fibroblasts expressed a higher level of OPN mRNA than the cells from WKY (1863.23+/-43.91 vs 326.24+/-68.29, p<0.01). To verify if OPN is associated with the enhanced migratory ability in AF from SHR, we designed the antisense oligonucleotide of OPN. The results showed that the antisense OPN oligonucleotide significantly inhibited AF migration (cell number per field 38.60+/-5.98 vs 26.61+/-3.84, p<0.05), while sense and mismatch OPN oligonucleotide had no effect on cell migration. Therefore, the migration of adventitial fibroblasts appeared to be enhanced in cultures derived from SHR. OPN might be involved in the difference observed.

To identify the genes that are differentially expressed during the phenotypic transition from vascular adventitial fibroblasts to myofibroblasts, the adventitial fibroblasts were cultured from rat thoracic aorta, and myofibroblasts were obtained by treatment of fibroblasts with TGF-beta1. Differential display PCR (DD-PCR) was used to screen for differentially expressed genes by comparison of mRNA extracted from the two cell populations. Bands upregulated or downregulated on DD gels were excised, reamplified, cloned and sequenced. DD results were verified by quantitative PCR and Northern blot analysis.Antisense oligonucleotide was transfected to study the effect of osteopontin on migration of AF. Differential display showed a significant difference in gene expression profile between the two cell types. A transcript that was downregulated in myofibroblasts showed high DNA sequence homology to part of the gene for NADH dehydrogenase subunit 5. An upregulated transcript showed significant sequence homology to osteopontin gene. Quantitative PCR and Northern blot analysis confirmed the DD results. Among the other differential bands detected, 4 candidate sequences showed no homology to the known genes. The AF numbers of migration were significantly decreased by use of OPN antisense oligonucleotide. This study suggests that the downregulation of gene encoding NADH dehydrogenase subunit 5 and upregulation of osteopontin gene and several other unknown genes may be involved in the phenotypic transition of adventitial fibroblasts to myofibroblats. Inhibition of the expression of OPN may play an important role in the process of vascular remodeling.