Abstract:Atherosclerosis (As) is a chronic inflammatory arterial wall injury process, and vessel wall cells play an important role in the occurrence and development of As. Vascular endothelial cell (VEC) act as a semi-permeable barrier between vascular smooth muscle cell (VSMC) and vascular lumen, and its injury is the initial stage of As. In addition, Through phenotypic transformation, VSMC could transform into many cell phenotype of the plaques, including macrophage, foam cell, mesenchymal stem cell and so on, and these cells further involved in the occurrence of As. Fibroblast is the main component of vascular adventitia,in pathological conditions, fibroblast differentiate into myofibroblast and participate in the occurrence of As. In this article, we will review the involvement of vascular wall cells in the mechanism of As and its potential therapeutic targets for the treatment of As, which provide new therapeutic ideas for As.

Abstract:Scholars often focus on the formation of vascular intimal atherosclerosis (As) plaque, but pay little attention to the immune response of vascular adventitia and its impact on the course of the disease. Previous studies have found that there are orderly aggregate of immune cells in the adventitia of aged ApoE－/－ mice, forming ectopic lymphoid tissue similar to lymph node, which is called artery tertiary lymphoid organs (ATLO), and its formation has an obvious regulatory effect on intimal As. The discovery and study of ATLO point out a new direction for the study of As and provide a good example for the study of tertiary lymphoid organ (TLO) in other diseases. Therefore, clarifying the characteristics and formation mechanism of TLO is of great significance for the prevention and treatment of As, and provides a solid foundation for its clinical application in other diseases.

Abstract:The vascular adventitia is layered with loose connective tissue, which includes external elastic lamina, vasa vasorum, and nerve ending. Fibroblasts are the main cellular components of the adventitia. In the previous studies, the vascular adventitia is considered to only play roles in nourishing blood vessels and maintaining the tension and structure of blood vessels. Recent studies have found that vascular adventitia secretes a variety of bioactive polypeptides as an autocrine/paracrine manner. These bioactive polypeptides play a vital role in the maintenance of vascular homeostasis and vascular injury diseases such as atherosclerosis, abdominal aortic aneurysm, hypertension, pulmonary arterial hypertension, vascular calcification and restenosis after angioplasty. Paying attention to and strengthening the research on the biological effects of paracrine/autocrine bioactive polypeptides from vascular adventitia and their roles in the maintenance of vascular homeostasis and injury diseases has important significance for the maintenance of vascular homeostasis and the understanding of the pathogenesis of vascular injury diseases.

Abstract:Coronary atherosclerosis is a chronic inflammatory disease that affects the structure and function of coronary arteries, leading to a series of cardiovascular events. In recent years, the study on the pathogenesis of atherosclerosis in the adventitia of coronary arteries has attracted more and more attention. The adventitia is made up of fibroblasts, progenitor cells, immune cells, microvessels and adrenergic nerves, which surround perivascular adipose tissue. All kinds of tissues and cells of the adventitia have high metabolic activity, which can regulate the structure and function of the whole vascular wall “from the outside to the inside” and participate in the formation of atherosclerosis. This paper reviews the recent advances in the pathogenesis of coronary atherosclerosis in the adventitia of arteries.

Abstract:Aim To observe the effect of interferon-inducible protein 204 (p204) on the apoptosis, proliferation and migration of vascular adventitial fibroblast cells (VAF) in rat. Methods The specific small interference RNA (siRNA) of p204 gene (Ifi204) were transfected into VAF in vitro instantaneously. VAF were divided into three groups, Ifi204 siRNA transfection group (Ifi204-siRNA), control siRNA transfection group (Con-siRNA), untreated VAF as a negative intervention control group (Neg). Then the cell vitality to reflect cell proliferation was analyzed by MTT method, cell apoptosis was analyzed by flow cytometry, cell migration by scratch assay and transwell chamber. The mRNA and protein levels of p204, p53 and p21 were measured by real-time qRT-PCR and Western blot, respectively. Results After transfection of the Ifi204 siRNA, the mRNA and protein expression levels of p204, p53 and p21 were decreased in the VAF, and the cell apoptosis was inhibited, the cell proliferation and migration were promoted. Conclusion Inhibition of p204 expression can promote VAF cell growth and migration, which may be related to the inhibition of p53 and p21 expression.

Abstract:Aim To investigate the effect of interferon-inducible protein 16 (IFI16) siRNA on the proliferation and apoptosis of interferon-α (IFN-α) induction of human brain vascular adventitial fibroblasts (HBVAF). MethodsThe siRNA of IFI16 gene was transfected into HBVAF in vitro. 48 hours after transfection, the cells were exposed to 2×106 U/L IFN-α for 24 h. Cell cycle and apoptosis were analyzed by flow cytometry. The mRNA and protein levels of IFI16 were measured by real-time PCR and Western blot. Results After transfection with IFI16 siRNA, the expression of IFI16 mRNA and protein levels was decreased in HBVAF, and the cell cycle at G/S transition was promoted.Meanwhile, stimulated with IFN-α up-regulated the expression of IFI16 mRNA and protein levels, and inhibited the cell cycle transition at G/S and promoted cells apoptosis in HBVAF. Such effect was restrained by transfection with IFI l6 siRNA into HBVAF. Conclusion IFN-α may inhibit cells proliferation and promote cells apoptosis of HBVAF by up-regulating the expression of IFI16.

Abstract:Aim To explore the effect of urotensin Ⅱ （UⅡ） on expression of interleukin-6 （IL-6） in rat aortic adventitial fibroblast （AF） and its intracellular mechanisms. Methods Growth-arrested AF was incubated in serum-free medium with UⅡ （10－10～10－7 mol/L）. In order to explore the mechanism of UⅡ effects, the cells were pretreated with some inhibitors of signal transduction pathways for 30 min, and then incubated with UⅡ （10－8 mol/L） for 3 h to 24 h. The IL-6 mRNA expression in the cells and secretion from the cells induced by UⅡ were evaluated by reverse transcription polymerase chain reaction （RT-PCR） and enzyme-linked immunosorbent assay （ELISA）, respectively. Results （1）UⅡ significantly increased IL-6 mRNA expression and protein secretion in rat AF, in a concentration-dependent （10－10～10－7 mol/L） and a time-dependent manner, with maximal effect at 10－8 mol/L at 3 h for mRNA expression, or at 24 h for protein secretion （both P<0.01）. （2）The effect of UⅡ was inhibited by SB710411 （10－6 mol/L）, nicardipine （10－5 mol/L）, PD98059 （10－5 mol/L）, H7 （10－5 mol/L）, Y-27632 （10－5 mol/L） and cyclosporine A （CsA） （10－5 mol/L）, the inhibitors of UⅡ receptor, Ca2＋ channel, mitogen activated protein kinase, protein kinase C, Rho kinase, and calcineurin, respectively. Conclusion UⅡ significantly induces IL-6 expression in rat AF, via activation of its receptor, Ca2＋ channel, mitogen activated protein kinase, protein kinase C, Rho kinase and calcineurin signal transduction pathways, indicating that UⅡ induced-IL-6 expression is one of the important mechanisms responsible for accelerated atherosclerosis.

Abstract:The relationship between carotid artery atherosclerosis and cardiovascular and cerebrovascular diseases are so close, some parameters which represent carotid artery atherosclerosis including carotid artery intima-media thickness, carotid artery plaque and carotid artery adventitia have positive correlation with cardiovascular and cerebrovascular diseases, and predict cardiovascular events and cerebrovascular events.

Abstract:Aim To study the relationship between the phenotypic differentiation of adventitial fibroblasts and the early atherosclerotic lesion formation. Methods ApoE-/- mice and wild-type C57BL/6 black mice of 6 weeks were used in this experiment. All animals were fed hyperlipidic diet for 2, 4 or 8 weeks. The ascending aorta was removed for serial sectioning. Some sections were stained with immunohistochemistry to observe the expression of α-smooth muscle-actin（α-SM-actin） and transforming growth factor beta 1 （TGF-β1 ） in the adventitia at different time points. In addition the arterial adventitial fibroblasts derived from ApoE-/- mice and C57BL/6 mice after hyperlipidic diet for 2 weeks were cultured. The expression of α-SM-actin was examined by immunofluorescence staining and Western Blot. The ultrastructural changes were observed by transmission electromicroscope. The expression of TGF-β1 protein was verified by Western Blot. Results In vivo the adventitia exhibited positive expression of α-SM- actin after hyperlipidic diet for 2 and 4 weeks but weakly positive staining for α-SM-actin expression after hyperlipidic diet for 8 weeks. TGF-β1 expression increased gradually in the adventitia with increasing duration of the hyperlipidic diet. However there was no α-SM-actin and TGF-β1 expression in the adventitia of C57BL/6 mice all the time. In vitro part cells of ApoE-/- mice showed positive α-SM-actin and obvious increase of filaments. But that was not found in C57BL/6 mice. The protein levels of α-SM-actin and TGF-β1 were higher than C57BL/6 mice（P<0.05）. Conclusion The adventitial fibroblasts were differentiated into myofibroblasts at the early stage of atherosclerosis.

Abstract:Aim To discuss a set of system to culture vascular smooth muscle cell(VSMC),vascular adventitial fibroblast(VAF) and vascular endothelial cell(VEC) from murine aorta,which are simple,reliable and easy to replicate. Methods The primary culture of VSMC,VAF and VEC used the tissue adherent method,trypsin digestion for passage transfer. The cells were purified by differential adherent and natural growth purification. Myofibroblast(MF) was transformed from VAF by growth factor-β1(TGF-β1) induced. Phase contrast microscope and immunocytochemistry staining were used to identify the morphological and the immunological characteristics,respectively. Results The tissues and cells activity were excellent. The growth cycle of primary VSMC/VAF and VEC were 10~12 days and 12~14 days,respectively. And passage cycle was 7~10 days. After being purified and subculture,the cells purity achieved 95%~100%. The growth characteristics of VSMC assumed the model peak and valley,and with anti α-SMA(+) /Vimentin(-);the VEC assumed pebble-like appearance,and anti CD31(+)/α-SMA(-);the staining of VAF were Vimentin(+)/α-SMA(-),while the induction MF were Vimentin(+)/α-SMA(+). The primary cells were successfully passaged more than 10 generations,without growth vigor decreasing. Conclusion We have established a set of system methods to culture the primary VEC,VSMC,VAF and MF of rat aorta origin,the advantages of our approach are simple,reliable and easy to replicate,while the cells have high purity and excellent biological activity. This method is still suitable for culturing the ingredient cell of mouse aorta vessel wall.