Hypercholesteremia was induced by cholesterol feeding of rabbits for 10 weeks. Gross examination of aorta of these animals showed an evidence of atheromatous lesions. The endogenous catecholamines in heart, adrenal gland, spleen, brain, liver and kidney of these hypercholesteremic rabbits were markedly reduced as compared to those of normal animals, respectively. There may exist some correleration between the serum cholesterol and tissue catecholamines.
Animal ; Arteriosclerosis/etiology* ; Arteriosclerosis/metabolism ; Carbon Isotopes ; Catecholamines/metabolism* ; Cholesterol/blood* ; Female ; Rabbits

Chronic infection and inflammation have recently been implicated as important etiologic agents for atherosclerosis in general and, in particular, ischemic heart disease. Several agents have been suggested as possible candidates for the chronic inflammation including cytomegalovirus, Helicobacter pylori and Chlamydia pneumoniae. We hypothesized that a vascular infection with C. pneumoniae may induce a chronic inflammatory reaction in the host vascular tissue and activated inflammatory cells may express inflammatory mediators such as cyclooxygenase-2 (COX-2) and matrix metalloproteinases (MMPs). At first, we evaluated the relationship between C. pneumoniae infection and atherosclerosis indirectly by serologic study, and then, to confirm our hypothesis, we performed an immunohistochemical study of atherosclerotic plaques. The seropositive rate of anti-Chlamydia pneumoniae IgG was higher in the disease group (Group I, 59.8%, n = 254) than in the negative control group (Group III, 47.4%, n = 97) (p = 0.041), but the anti-Chlamydia pneumoniae IgA was not different in seropositivity between the two groups (Group I, 64.6%; Group III, 57.7%). The simultaneous seropositive rates of both IgG and IgA were 56.7% in Group I and 43.3% in Group III (p = 0.033). In subgroups without the conventional risk factors of atherosclerosis, these findings were more prominent. Furthermore, we performed immunohistochemical staining on the atherosclerotic aortic tissues obtained from patients that were seropositive to C. pneumoniae (n = 5), by using antibodies to C. pneumoniae, COX-2, and MMP-9. The immunoreactivity for COX-2 and MMP-9 increased in the atherosclerotic plaques itself, predominantly in the surrounding area of immunoreactive C. pneumoniae. These findings support our hypothesis and C. pneumoniae may participate in a pathogenetic mechanism for atherogenesis or progression of atherosclerosis. The present study may open a promising perspective concerning future therapeutic trials of chronic inflammation related atherogenesis under pathophysiological conditions.
Aged ; Arteriosclerosis/pathology* ; Arteriosclerosis/microbiology* ; Arteriosclerosis/metabolism ; Chlamydia Infections/complications* ; Chlamydophila pneumoniae ; Female ; Gelatinase B/metabolism ; Human ; Isoenzymes/metabolism ; Male ; Middle Age ; Prostaglandin-Endoperoxide Synthase/metabolism ; Serologic Tests*

Neovascularization of the adventitial vasa vasorum with extension into the intima of atherosclerotic lesions is frequently observed, but its pathophysiological significance is still subject to debate. Recently, leptin, the product of the Ob gene, was identified. Leptin, via activation of the endothelial receptor (Ob-R), generates a growth signal involving a tyrosine kinase-dependent intracellular pathway and promotes angiogenic processes. We hypothesized that a high concentration of leptin within vasa vasorum and plaque itself, may influence inflammatory and vascular neovascularization coupling with functional upregulation of the vascular endothelial growth factor (VEGF). Microscopic computerized tomography was utilized for the spatial distribution of vasa vasorum and intimal neovascularization from atherosclerotic human coronary arteries. Atherosclerotic coronary arteries showed a dense plexus of microvessels in the adventitia and plaque itself. Microscopic analysis from human atherosclerotic aortas revealed an increase in the intimal thickness with neovascularization. The immunoreactivity for Ob-R, VEGF and matrix metalloproteinase (MMP) increased in atherosclerotic plaque, predominantly in the endothelial lining of the intimal neovessel and macrophages/foam cells. Our observation of a prominent colocalization between Ob-R, VEGF and MMP supports this hypothesis and these factors participate in the neovascularization of atherosclerotic lesions. The present study is the first report on vascular tissue and it opens a promising perspective concerning future investigations of leptin-dependent modulation of atherogenesis and vascular neovascularization under pathophysiolgical conditions.
Adult ; Arteriosclerosis/physiopathology ; Arteriosclerosis/pathology ; Arteriosclerosis/metabolism* ; Blood Vessels/pathology ; Blood Vessels/metabolism ; Carrier Proteins/physiology ; Carrier Proteins/metabolism* ; Human ; Middle Age ; Neovascularization, Pathologic/physiopathology

AIMTo study the expressions of scavenger receptor class B type I(SR-BI) and peroxisome proliferator-activated receptor gamma (PPARgamma) in atherosclerotic mini swine and provide a new mechanism for investigating the pathogenesis of atherosclerosis.

METHODSChinese mini swine were fed by a normal control diet or a high fat/high cholesterol diet for 12 months after common carotid artery injury induced by balloon denudation. Plasma total cholesterol(TC), high-density lipoprotein cholesterol (HDL-C) and triglycerides (TG) were determined by commercially enzymatic methods every two months. The sections, which were taken from liver and abdominal aorta, were stained with hematoxylin eosin. The expressions of SR-BI and PPARgamma mRNA and protein in liver and aorta tissue were detected by reverse transcriptase-polymerase chain reaction (RT-PCR), Western blot and immunohistochemistry respectively.

RESULTSAt the end of 12 months, plasma TC, HDL-C and TG in HFHC mini swine were increased. There were fatty liver and atherosclerotic plaque in mini swine live and aorta respectively. The expression of SR-BI was upregulated in HFHC mini swine liver and aorta tissue.

CONCLUSIONHFHC may induce atherosclerosis and the expression of SR-BI and PPARgamma. Upregulating SR-BI expression may inhibit atherosclerosis. Increasing SR-BI expression in liver and aorta may accelerate SR-BI-mediated reverse cholesterol transport and develop a new anti-atherogenic strategy.

Animals ; Arteriosclerosis ; pathology ; Atherosclerosis ; metabolism ; PPAR gamma ; metabolism ; Receptors, Scavenger ; metabolism ; Swine

Advanced atherosclerosis is often associated with dystrophic calcification and remodeling of extracellular matrix of vascular wall. Recently many studies have documented a general relationship between calcification and severity of coronary disease, and discussed the feasibility of electron beam computed tomography for detecting and quantifying the coronary artery calcification in the patients. The present study investigated the expression and the localization of osteopontin, one of noncollagenous bone matrix protein, within the calcified coronary arteries. Autopsy-derived coronary artery specimens were scanned and reconstructed to visualize the pattern of coronary calcification using a novel microscopic computed tomography technique. The localization of the osteopontin were evaluated by immunohistochemial stain with LF7. The present study showed that the pattern of coronary calcification is variable and the expression of osteopontin is localized mainly to calcified lesion. The smooth muscle cells in addition to macrophage expressed osteopontin protein in human coronary atherosclerotic plaques. Soluble osteopontin released near to the sites of vascular calcification may represent an adaptive mechanism aimed at regulating the process of vascular calcification.
Aged ; Calcinosis/metabolism ; Coronary Arteriosclerosis/pathology* ; Coronary Arteriosclerosis/metabolism* ; Coronary Vessels/pathology* ; Coronary Vessels/metabolism ; Coronary Vessels/chemistry* ; Female ; Human ; Immunohistochemistry ; Male ; Middle Age ; Sialoglycoproteins/biosynthesis ; Sialoglycoproteins/analysis*

OBJECTIVETo identify distinct proteins involved in human atherosclerosis obliterans (ASO) by a differential proteomic approach.

METHODSEight atherosclerotic femoral arteries with a mean age of 68.6 years (6 male and 2 female) and 5 normal femoral arteries with a mean age of 44.2 years (3 male and 2 female) were obtained from high amputation patients. Then the first 2-dimensional maps of the proteome of human femoral arteries was plotted to compare ASO and control specimens. Proteomic profiling was to differentiate and identify histological proteins that were associated with ASO. The differentially expressed proteins were sequenced by matrix assisted laser desorption/ionization mass spectrometry (MALDI-TOF-MS). The result was verified by immunohistochemistry (IHC) and Western blot.

RESULTSASO was associated with distinct patterns of protein expression in the femoral arteries. A total of 25 distinct spots corresponding to 13 different proteins were identified by MALDI-TOF-MS using the NCBI and IPI databases. These proteins were mainly involved in the pathogenetic mechanisms such as inflammation, oxidative stress, proliferation and transformation of SMCs. The low level of heat shock protein 27 (HSP27) in ASO was verified by IHC and western-blot in accord with the result of MS.

CONCLUSIONProteomic analysis can be used to investigate differentially expressed proteins, which may provide new insights into ASO pathogenesis, such as HSP27.

Adult ; Aged ; Arteriosclerosis Obliterans ; metabolism ; pathology ; Female ; Humans ; Male ; Middle Aged ; Proteome ; metabolism

OBJECTIVE: To explore the relationship between activity of plasma heparin cofactor II (HC II) and the incidence of in-stent restenosis aft er the intervention of arteriosclerosis obliterans in lower extremity. METHODS: A total of 62 patients with arteriosclerosis obliterans in lower extremity underwent femoropopliteal stent implantation. They were divided into 2 groups: A high HC II activity group (≥100%, n=40) and a low HC II activity group (<100%, n=22). All patients filled in follow up tables and conducted body examination. Possible risk factors resulting in restenosis were collected. Patients were followed up for 6 months after femoropopliteal stent implantation. RESULTS: Baseline clinical characteristics were not significantly different between the 2 groups. The degree and incidence of angiographic restenosis at the end of the 6th month after the implantation in the high HC II activity group were all significantly lower than those in the low HC II activity group (P<0.05). Multivariate analysis demonstrated that high plasma HC II activity was an independent factor in reducing the incidence of angiographic restenosis (OR=0.982, P=0.048, 95%CI, 0.966, 0.998). CONCLUSION High plasma HC II activity is an independent factor in reducing the degree of in-stent restenosis. The lower the plasma HC II activity, the severer the degree of in-stent restenosis.
Arteriosclerosis Obliterans ; surgery ; Constriction, Pathologic ; Heparin Cofactor II ; metabolism ; Humans ; Incidence ; Lower Extremity ; Risk Factors ; Stents

The role of very low density lipoprotein receptor (LVLDR) in the process of foam cell formation was investigated. After the primary cultured mouse peritoneal macrophages were incubated with VLDL, beta-VLDL or low density lipoprotein (LDL), respectively for 24 h and 48 h, foam cells formation was identified by oil red O staining and cellular contents of triglyceride (TG) and total cholesterol (TC) were determined. The mRNA levels of LDLR, LDLR related protein (ILRP) and VLDLR were detected by semi-quantitative RT-PCR. The results demonstrated that VLDL, beta-VLDL and LDL could increase the contents of TG and TC in macrophages. Cells treated with VLDL or beta-VLDL showed markedly increased expression of VLDLR and decreased expression of LDLR, whereas LRP was up-regulated slightly. For identifying the effect of VLDL receptor on cellular lipid accumulation, ldl-A7-VR cells, which expresses VLDLR and trace amount of LRP without functional LDLR, was used to incubate with lipoproteins for further examination. The results elucidated that the uptake of triglyceride-rich lipoprotein mediated by VLDLR plays an important role in accumulation of lipid and the formation of foam cells.
Animals ; Arteriosclerosis ; metabolism ; pathology ; Cells, Cultured ; Cholesterol, LDL ; metabolism ; pharmacology ; Female ; Foam Cells ; cytology ; metabolism ; Lipoproteins, VLDL ; pharmacology ; Macrophages, Peritoneal ; cytology ; metabolism ; Mice ; Receptors, LDL ; metabolism ; Triglycerides ; metabolism

Inflammation appears to have a major role in the development of atherosclerosis. Cyclooxygenase-2 (COX-2) is involved in the inflammatory response via the generation of prostanoids that, in turn, are involved in the production of matrix metalloproteinases (MMPs). This study aimed to investigate atherosclerosis in human aortas for in situ tissue distribution of COX-2, MMPs including MMP-9 and membrane type 1 MMP (MT1-MMP), and tissue inhibitor of metalloproteinase-2 (TIMP-2). Immunohistochemical studies were performed on atherosclerotic lesions of aortas from patients with aortic aneurysms (n = 4) and dissections (n = 3) by using antibodies to COX-2, MMP-9, MT1-MMP, and TIMP-2. Control tissues were obtained from traumatically dissected aortas (n = 2). All specimens from diseased aortas had atherosclerotic lesions ranging from fatty streak to atheromatous plaques. In control, there was no expression of COX-2, MMP-9, and MT1-MMP in all aortic layers. Immunoreactivity for COX-2 was predominantly noted in macrophages and smooth muscle cells (SMCs) of the intima including atherosclerotic plaque itself and the medial layer of the plaque base, as well as in SMCs and endothelial lining of the vasa vasorum in the adventitia. Immunoreactivity for MMP-9 and MT1-MMP was found in the same distribution as that of COX-2. Additionally, the expression of TIMP-2 increased in relation to MMP-9 expression. This study demonstrates that COX-2 is coexpressed with MMP-9 and MT1-MMP, not only by macrophages and SMCs in atherosclerotic lesions, but also in endothelial lining of the vasa vasorum of human aortas. Thus, vascular inflammatory reactions may influence extracellular matrix remodeling by coactivation of MMPs in the development of atherosclerosis and, in turn, the progression of disease.
Animal ; Aorta/enzymology* ; Aortic Diseases/pathology ; Aortic Diseases/enzymology* ; Arteriosclerosis/pathology ; Arteriosclerosis/enzymology* ; Female ; Guinea Pigs ; Human ; Immunochemistry ; Isoenzymes/metabolism* ; Male ; Matrix Metalloproteinases/metabolism* ; Middle Age ; Prostaglandin-Endoperoxide Synthase/metabolism*

BACKGROUND: Arteriosclerosis obliterans (ASO) is a major cause of adult limb loss worldwide. Autophagy of vascular endothelial cell (VEC) contributes to the ASO progression. However, the molecular mechanism that controls VEC autophagy remains unclear. In this study, we aimed to explore the role of the GRB2 associated binding protein 1 (GAB1) in regulating VEC autophagy. METHODS: In vivo and in vitro studies were applied to determine the loss of adapt protein GAB1 in association with ASO progression. Histological GAB1 expression was measured in sclerotic vascular intima and normal vascular intima. Gain- and loss-of-function of GAB1 were applied in VEC to determine the effect and potential downstream signaling of GAB1. RESULTS: The autophagy repressor p62 was significantly downregulated in ASO intima as compared to that in healthy donor (0.80 vs. 0.20, t = 6.43, P < 0.05). The expression level of GAB1 mRNA (1.00 vs. 0.24, t = 7.41, P < 0.05) and protein (0.72 vs. 0.21, t = 5.97, P < 0.05) was significantly decreased in ASO group as compared with the control group. Loss of GAB1 led to a remarkable decrease in LC3II (1.19 vs. 0.68, t = 5.99, P < 0.05), whereas overexpression of GAB1 significantly led to a decrease in LC3II level (0.41 vs. 0.93, t = 7.12, P < 0.05). Phosphorylation levels of JNK and p38 were significantly associated with gain- and loss-of-function of GAB1 protein. CONCLUSION Loss of GAB1 promotes VEC autophagy which is associated with ASO. GAB1 and its downstream signaling might be potential therapeutic targets for ASO treatment.
Adaptor Proteins, Signal Transducing ; Adult ; Arteriosclerosis Obliterans/genetics* ; Autophagy ; GRB2 Adaptor Protein ; Humans ; Phosphoproteins/metabolism* ; Phosphorylation ; Protein Binding ; Signal Transduction