THE ROLES OF bcl-2 GENE FAMILY IN THE PULMONARY ARTERY REMODELING OF HYPOXIA PULMONARY HYPERTENSION IN RATS

Objective. To investigate the roles of apoptosis in the pulmonary artery remodeling of pulmonary hypertension secondary to hypoxia and illustrate the relative genes expression. Methods. Thirty rats were divided into hypoxia group（ 10％ O2, 8h/d） and normal control group. On the 15th day of hypoxia, pulmonary artery pressure and right ventricular hypertrophy index were measured and pulmonary artery vessels were studied by light microscope. Then terminal deoxynucleotidyl transferase- mediated dUTP nick- end labeling（ TUNEL） technique was used to detect nucleosomal DNA fragmentation of apoptotic cells. In situ hybridization and RT- PCR were used to detect the expression level of bcl- 2 and bax. Results. The pulmonary artery pressure and right ventricular hypertrophy index of hypoxia group were increased significantly, the pulmonary artery wall of hypoxic group become incrassate than control group. Apoptotic cells can be found in lung with hypoxia or without hypoxia. Compared with control group, apoptotic index of hypoxic group decreased significantly. Through the methods of in situ hybridization and RT- PCR, we found the expression of bcl- 2 increased whereas bax decreased significantly in the hypoxic group. Conclusion. The alternation in bcl- 2 and bax expression induced by hypoxia play an important role in the pulmonary artery remodeling which is the main pathologic change of pulmonary hypertension secondary to hypoxia.

Histomorphological observation in arterial remodeling following New Zealand rabbit auto-extremity artery transplantation

Objective： To investigate the histomorphological change in auto-extremity artery following transplantation. Methods： 50 New Zealand rabbits were randomly divided into 5 groups（postoperative 1 d, 3 d, 7 d, 14 d, 56 d, n = 10）. Femoral artery was harvested and end-to-side anastomosed with carotid in order to build the auto-extremity arterial graft animal model. On the postoperative 1^st, 35^nd, 7^th, 14th and 56^th days, grafts for morphometric analysis under the Image analysis system were obtained; and electron microscope was scanned to observe endothelial cells. In addition, Immunostaining of sections were performed with the mouse monoclonal antibody of the a -smooth muscle isoform of actin and proliferating cell nuclear antigen antibody. Results： Overall patency rate for all conduits was 86%.The intimal hyperplasia was first observed in the 7^th day group, and continued to increase in the 56^th day group（183.21 ± 111.74） μ m, P 〈 0.01. Additionally, the luminal narrowed（32.43 ± 18.28）% in the 56^th day group. Smooth muscle cells were the mainly hyperplastic components. The most active proliferation of cells was detected in the 14^th day group, where the extracellular matrix gradually deposited in the intima. Conclusion： Moderate intimal hyperplasia occurred in arterial conduits and vascular structure experienced constrictive remodeling after auto-transplantation.

Carotid remodeling of hypertensive subjects and polymorphism of the angiotensin-converting enzyme gene

Background This study was designed to investigate the relationships between changes in the structure and function of carotid arteries and angiotensin converting enzyme (ACE) gene polymorphism in Chinese hypertensive subjects. Methods Multiplex polymerase chain reaction amplification was used to evaluate the ACE gene insertion/deletion (I/D) polymorphism. High-resolution B-mode ultrasound examinations were performed to detect parameters of carotid artery remodeling. Results Intima-media thickness (IMT) was significantly different among the DD, ID and II genotypes of ACE (DD>ID>II, P <0.05). Carotid internal diameter,distensibility and stiffness were similar among the DD,ID and II genotypes of ACE ( P >0.05) in hypertensive subjects. The frequency of the DD gene and D allele of ACE were higher in patients with thickening carotid than in patients with normal carotid (70.4% vs 24.1%,and 79.5% vs 40.5%,respectively, P <0.001). In multiple stepwise regression analysis,independent risk factors for increased carotid IMT in hypertensive subjects were ACE genotypes ( P <0.001),age ( P <0.001) and carotid internal diameter ( P =0.032). Moreover,triglycerides and total cholesterol were higher in patients with the DD genotype than in those with the II genotype ( P <0.05). Conclusions The I/D polymorphism of the ACE gene was related to IMT,but not to internal diameter,distensibility and stiffness of the carotid in Chinese hypertensive subjects. ACE gene polymorphism was a main risk factor for increased carotid IMT. These results may imply that there is a link between lipid metabolism and ACE genotype polymorphism in Chinese hypertensive subjects.

Mechanism of arterial remodeling in chronic allograft vasculopathy

Chronic allograft vasculopathy(CAV)remains a major obstacle for long-term survival of grafts even though therapeutic strategies have improved considerably in recent years.CAV is characterized by concentric and diffuse neointimal formation,medial apoptosis,infiltration of lymphocyte or inflammatory cells,and deposition of extracellular matrix both in arteries and veins.Recent studies have shown that stem cells derived from the recipient contribute to neointimal formation under the regulation of chemokines and cytokines.Arterial remodeling in allografts eventually causes ischemic graft failure.The pathogenesis is multi-factorial with both immunologic and non-immunological factors being involved.The immunological factors have been discussed extensively in other articles.This review focuses mainly on the arterial remodeling that occurs in 3 layers of vessel walls including intimal injury,accumulation of smooth muscle-like cells in the neointimal,medial smooth muscle cell apoptosis,adventitial fibrosis,and deposition of extracellular matrix.

Adrenomedullin and endocrine control of immune cells during pregnancy

The immunology of pregnancy is complex and incompletely understood. Aberrant immune activity in the decidua and in the placenta is believed to play a role in diseases of pregnancy, such as infertility, miscarriage, fetal growth restriction and preeclampsia. Here, we briefly review the endocrine control of uterine natural killer cell populations and their functions by the peptide hormone adrenomedullin. Studies in genetic animal models have revealed the critical importance of adrenomedullin dosage at the maternal-fetal interface, with cells from both the maternal and fetal compartments contributing to essential aspects underlying appropriate uterine receptivity, implantation and vascular remodeling of spiral arteries. These basic insights into the crosstalk between the endocrine and immune systems within the maternal- fetal interface may ultimately translate to a better understanding of the functions and consequences of dysregulated adrenomedullin levels in clinically complicated pregnancies.