The expression pattern of vascular endothelial growth factor C and D in human esophageal normal mucosa, dysplasia and neoplasia

BACKGROUND/AIMS: Vascular endothelial growth factor C (VEGF-C) and D (VEGF-D) are considered to be potentially lymphangiogenic and can selectively induce hyperplasia of the lymphatic vasculature. In this study, we examined the expression of VEGF-C and -D in esophageal carcinoma. METHODOLOGY: With immunohistochemical staining using specific antibodies, we classified 26 esophageal carcinoma cases and 11 dysplasia cases. RESULTS: All esophageal carcinomas clearly expressed VEGF-C. In esophageal dysplasia, 9 (82%) lcases were positive for VEGF-C, and 2 (18%) were negative. In contrast, none of the normal esophageal mucosa expressed VEGF-C. Seventeen (65%) of 26 cases of esophageal carcinoma were positively stained for VEGF-D and 7 (35%) were negative. VEGF-D was also positive in 2 (18%) cases of esophageal dysplasia, but in no cases of normal tissue. VEGF-C was detected in all carcinomas and dysplastic lesions that expressed VEGF-D. CONCLUSIONS: Active production of VEGF-C and -D was observed not only in esophageal carcinomas but also in some dysplastic lesions. This finding raises the possibility that VEGF-C and -D might play positive roles in the early stage of esophageal carcinogenesis.     

Apoptosis of vascular smooth muscle cells is induced by Fas ligand derived from monocytes/macrophage

Fas and its ligand (FasL), are a receptor-ligand pair identified as promoting cell death in several tissues. Apoptosis of vascular smooth muscle cells (VSMCs) in human atherosclerotic plaque may contribute to weakening of the fibrous cap, ultimately resulting in plaque rupture. We investigated the ability of monocytes to induce apoptosis of cultured VSMCs through Fas/FasL pathway. In addition, we examined the association of FasL with apoptosis in human coronary plaques. Both activated monocytes and the supernatant obtained from activated monocytes were able to kill cultured VSMCs. The apoptotic response of VSMCs was almost completely blocked by the caspase inhibitor z-VAD-fmk and was partially blocked by incubation with antagonistic anti-Fas IgG1 which suggests that Fas/FasL system was involved in the induction of cell death. An approximate 30 kDa protein, which represents a cleaved, soluble form of FasL, was identified in culture medium from activated monocytes, but not in culture medium from control, unactivated monocytes. Immunohistochemical analysis of human atherosclerotic coronary lesions showed that FasL is expressed by macrophages, and microvessels in the adventitia as well as in the plaque. Finally, double-staining with terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) and FasL antibody showed that FasL enriched lesions always included a number of TUNEL-positive cells. These data suggest that Fas/FasL pathway can be employed by monocytes/macrophages to induce VSMC apoptosis in the atherosclerotic lesions.     

Vascular endothelial growth factor-D expression in human atherosclerotic lesions

OBJECTIVE: Vascular endothelial growth factor-D (VEGF-D) is a recently characterized member of the VEGF family, but its expression in atherosclerotic lesions remains unknown. We studied the expression of VEGF-D and its receptors (VEGFR-2 and VEGFR-3) in normal and atherosclerotic human arteries, and compared that to the expression pattern of VEGF-A. METHODS: Human arterial samples (n=39) obtained from amputation operations and fast autopsies were classified according to the stage of atherosclerosis and studied by immunohistochemistry. The results were confirmed by in situ hybridization and RT-PCR. RESULTS: We found that while VEGF-A expression increased during atherogenesis, VEGF-D expression remained relatively stable only decreasing in complicated lesions. In normal arteries and in early lesions VEGF-D was mainly expressed in smooth muscle cells, whereas in complicated atherosclerotic lesions the expression was most prominent in macrophages and also colocalized with plaque neovascularization. By comparing the staining profiles of different antibodies, we found that proteolytic processing of VEGF-D was efficient in the vessel wall. VEGFR-2, but not VEGFR-3, was expressed in the vessel wall at every stage of atherosclerosis. CONCLUSIONS: Our results suggest that in large arteries VEGF-D is mainly expressed in smooth muscle cells and that it may have a role in the maintenance of vascular homeostasis. However, in complicated lesions it was also expressed in macrophages and may contribute to plaque neovascularization. The constitutive expression of VEGFR-2 in arteries suggests that it may be one of the principal mediators of the VEGF-D effects in large arteries.     

Low thrombogenicity of calcified atherosclerotic plaques is associated with bone morphogenetic protein-2-dependent inhibition of tissue factor expression

Morphology of atherosclerotic plaque is a major determinant of plaque thrombogenicity. Calcified atherosclerotic lesions are less prone to thrombosis and contain less tissue factor (TF) than lipid-rich plaques. Although bone morphogenetic protein (BMP)-2 is a known mediator of vascular calcification, the role of BMP-2 in the regulation of plaque thrombogenicity has not been established. We hypothesized that the expression of BMP-2 within highly calcified atherosclerotic plaques inhibits TF expression and reduces thrombogenicity of calcified lesions. In the present study, we measured levels of TF and BMP-2 in human calcified and lipid-rich carotid plaques and studied the effects of BMP-2 on TF expression in human monocytes in vitro. Quantitative immunohistochemical analysis of endarterectomy specimens for TF and BMP-2 revealed that calcified plaques contained nearly three-times less TF antigen than lipid-rich ones. In contrast, calcified plaques expressed two-times more BMP-2 antigen than lipid-rich lesions. BMP-2 markedly decreased protein expression and surface redistribution of TF in activated human monocytes in vitro. BMP-2-mediated inhibition of TF expression in monocytes/macrophages could contribute to reduced thrombogenicity of calcified atherosclerotic plaques.     

Vascular endothelial growth factors C and D and their VEGFR-2 and 3 receptors in blood and lymphatic vessels in healthy and arthritic synovium

OBJECTIVE: To localize vascular endothelial growth factor C (VEGF-C) and VEGF-D in synovial specimens in relation to their VEGFR-2 and VEGFR-3 receptors in blood and lymphatic vessels. METHODS: Immunohistochemical staining and messenger RNA analysis from control and arthritic synovial membrane specimens. RESULTS: Quantitative RT-PCR disclosed that VEGF-C mRNA copy numbers were higher than VEGF-D mRNA copy numbers in the rheumatoid arthritis (RA), osteoarthritis, and control patient groups studied (p < 0.01). Immunohistochemical staining localized VEGF-C to synovial lining cell layer, pericytes, and smooth muscle cells of blood vessels. The number of VEGF-C positive cells was increased in the synovial lining of ankylosing spondylitis (AS) and RA compared to control synovium. However, in contrast to control synovial lining, little if any VEGF-D was detected in AS or RA synovial lining. VEGFR-2 expressing stromal blood vessels, also positive for the vascular endothelial marker PAL-E and the basement membrane marker laminin, were more abundant in RA and AS than in controls. Interestingly, the lymphatic endothelial receptor VEGFR-3 was also expressed in most synovial vessels, especially in the sublining capillaries and venules. CONCLUSION: VEGF-C is strongly expressed in the hypertrophic synovial lining of arthritic joints, whereas VEGF-D expression is very low in AS and RA. The expression of VEGF-C and VEGF-D in pericytes and smooth muscle cells suggests that these factors may have a role in maintaining vascular homeostasis. The VEGF receptors VEGFR-2 and VEGFR-3 are present in most of the sublining blood vessels. The expression of the lymphatic marker VEGFR-3 in the sublining blood vessels may relate to fluid filtration and/or fenestrations. The relatively few lymphatic vessels along with increased vascular permeability in RA may contribute to the development of tissue edema and joint stiffness.     

Apoptosis and angiogenesis are induced in the unstable coronary atherosclerotic plaque

OBJECTIVE: Apoptosis and angiogenesis may be involved in the pathogenesis of atherosclerosis and plaque destabilization. In this study, we investigated if apoptosis and angiogenesis were induced in the unstable human coronary atherosclerotic plaque compared to stable atherosclerotic plaque. METHODS: Atherosclerotic plaques from patients with stable (n = 9) and unstable angina (n = 13) were obtained by directional coronary atherectomy performed during percutaneous transluminal coronary angioplasty. Apoptosis was detected by terminal deoxynucleotidyl transferase end labelling (TUNEL), as well as by immunostaining for caspase 3, Bax and Bcl-2. Neovascularization was determined by immunostaining for the endothelial cell-specific CD31, vascular endothelial growth factor (VEGF-A), angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2), hypoxia inducible factor-1alpha (HIF-alpha), and the sections were quantified blindly. RESULTS: The apoptotic nuclei were more frequently found in the unstable coronary atherosclerotic plaques. When the number of apoptotic cells was quantified, an increased apoptotic index was found in the unstable plaques (P = 0.04). The positive staining for caspase-3 was increased in the unstable plaques (P = 0.0008), while no difference in either Bax or Bcl-2 was found between groups. Neovascularization, as evidenced by lumens surrounded by a CD31 positive endothelial layer, was more frequently present in the plaques from patients with unstable angina (P = 0.04). The number of cells with positive staining for VEGF-A was increased in unstable plaques (P = 0.005). No difference of Ang I, Ang II, HIF1-alpha was found between groups. CONCLUSIONS: In unstable human coronary plaques, apoptosis probably involving caspase 3 was found. The plaques had an increased neovascularization, probably induced by VEGF-A. These factors may contribute to explaining plaque destabilization and intraplaque haemorrhage.     

Human blood-derived macrophages induce apoptosis in human plaque-derived vascular smooth muscle cells by Fas-ligand/Fas interactions

Human atherosclerotic plaques that rupture are characterized by relatively low vascular smooth muscle cell (VSMC) and high inflammatory cell contents. Ruptured plaques also contain higher numbers of apoptotic VSMCs than do stable lesions, suggesting that VSMC apoptosis may promote plaque rupture. We examined the ability of human monocytes/macrophages to induce apoptosis of VSMCs derived from human carotid plaque, aortic media, and coronary media. Macrophages, but not T lymphocytes, induced a dose-dependent apoptosis of VSMCs, which required monocyte maturation to macrophages and direct cell-cell contact/proximity. VSMC apoptosis was inhibited by neutralizing antibodies to Fas-ligand (Fas-L) or an Fas-Fc fusion protein, indicating the requirement for membrane-bound Fas and Fas-L. Monocyte maturation was associated with increased surface expression of Fas-L, coincident with the onset of cytotoxicity. VSMCs expressed surface Fas, which was increased in plaque VSMCs, and plaque VSMCs also underwent Fas-induced apoptosis. We conclude that human macrophages potently induce human VSMC apoptosis, which requires direct cell-cell interactions and is in part dependent on Fas/Fas-L interactions. Macrophage-induced VSMC apoptosis may therefore directly promote plaque rupture.     

Lymphangiogenesis in aortic valve stenosis--novel regulatory roles for valvular myofibroblasts and mast cells

ObjectiveTo investigate mechanisms of lymphangiogenesis in aortic valve stenosis (AS).MethodsLymphatic vessels were visualized with LYVE-1 staining in 20 control, 5 sclerotic, and 40 stenotic human aortic valves. Vascular endothelial growth factors (VEGFs) VEGF-C and VEGF-D, and their lymphangiogenic receptor VEGFR-3, and the angiogenic VEGFR-2 were analysed by quantitative real-time PCR and immunohistochemistry. Cultured myofibroblasts derived from human stenotic aortic valves, and cultured human mast cells were used to study VEGF-C regulation, and VEGF-C and VEGF-A were quantified from cell culture media by enzyme immunoassays.ResultsLymphatic vessels, VEGF-C, VEGF-D, VEGFR-3 and VEGFR-2 all were present in the aortic valves. In AS, the number of lymphatic vessels and the expression of VEGF-D, VEGFR-3, and VEGFR-2 were increased. Moreover, the numbers of lymphatic vessels correlated positively with those of neovessels (r = 0.525, p = 0.001) and mast cells (r = 0.374, p = 0.017). Cultured valvular myofibroblasts produced VEGF-C, and addition of tumour necrosis factor alpha (TNF-α) to the cells augmented its secretion. In contrast, proteases released by activated human mast cells degraded VEGF-C.ConclusionThese results show that lymphangiogenesis is induced in advancing AS. Furthermore, valvular myofibroblasts and activated mast cells were identified as novel regulators of lymphangiogenesis in aortic valves.     

Lymphatic reprogramming of microvascular endothelial cells by CEA-related cell adhesion molecule-1 via interaction with VEGFR-3 and Prox1

Here, we demonstrate that carcinoembryonic antigen-related cell adhesion molecule-1 (CEACAM1) is expressed and co-localized with podoplanin in lymphatic endothelial cells (LECs) of tumor but not of normal tissue. CEACAM1 overexpression in human dermal microvascular endothelial cells (HDMECs) results in a significant increase of podoplanin-positive cells in fluorescence-activated cell sorting analyses, while such effects are not observed in CEACAM1 overexpressing human umbilical vein endothelial cell (HUVECs). This effect of CEACAM1 is ceased when HDMECs are transfected with CEACAM1/y- missing the tyrosine residues in its cytoplasmic domain. CEACAM1 overexpression in HDMECs leads to an up-regulation of vascular endothelial growth factor C, -D (VEGF-C, -D) and their receptor vascular endothelial growth factor receptor 3 (VEGFR-3) at mRNA and protein levels. HDMECs transfected with CEACAM1 but not those with CEACAM1/y- show enhanced expression of the lymphatic markers Prox1, podoplanin, and LYVE-1. Furthermore, Prox1 silencing in HDMECs via small interfering RNA blocks the CEACAM1-induced increase of VEGFR-3 expression. Number and network of endothelial tubes induced by VEGF-C and -D are enhanced in CEACAM1-overexpressing HDMECs. Moreover, VEGF-A treatment of CEACAM1-silenced HDMECs restores their survival but not that with VEGF-C and VEGF-D. These data imply that the interaction of CEACAM1 with Prox1 and VEGFR-3 plays a crucial role in tumor lymphangiogenesis and reprogramming of vascular endothelial cells to LECs. CEACAM1-induced signaling effects appear to be dependent on the presence of tyrosine residues in the CEACAM1 cytoplasmic domain.     

不同转移潜能的小鼠肝癌淋巴道转移和淋巴管生成的研究

目的探讨小鼠淋巴道高、低转移潜能的肝癌细胞的体内淋巴道转移状况和淋巴管生成对淋巴道转移的影响。方法将淋巴道高、低转移潜能的肝癌细胞接种于Balb／C小鼠，观察成瘤及转移情况，对肿瘤组织进行淋巴管染色，观察淋巴管生成情况。另取高、低转移潜能的细胞株进行体外淋巴管生成实验并进行小鼠肿瘤转移基因芯片检测，对血管内皮细胞生长因子C、D（VEGF—C、D）进行半定量逆转录聚合酶链反应及实时定量聚合酶链反应分析。结果高，低转移细胞在小鼠髂总动脉旁、肾门淋巴结的转移差异有统计学意义（P=0．0l8）。高转移潜能组诱导淋巴管生成的数量大于低转移组和对照组（P=0．032）。高转移组的CD44、E-cadherin．HER2／neu、H—Ras．VEGF—C的表达均高于低转移组，nm23A．nm23-E4、pl6ink4a、CD61等均低于低转移组。半定量逆转录聚合酶链反应表明，高转移组vEGF—C高于低转移组，VEGF—D低于低转移组。实时定量聚合酶链反应分析高转移组的VEGF—D分泌显著小于低转移组，vEGF—C／VEGF—D在高转移组明显高于低转移组。结论肝癌的淋巴道转移与淋巴管生成有关，VEGF—C、D相关基因表达的改变影响淋巴管生成。VEGF—C／VEGF—D比值可能是有效判断并影响肝癌淋巴道转移潜能的指标之一。     

神经导向因子Netrin-1调节单核巨噬细胞迁移与动脉粥样斑块关系的研究进展

动脉粥样硬化是动脉壁的一种慢性炎症性疾病,单核巨噬细胞在其发生发展中起着关键作用。动脉粥样斑块中单核巨噬细胞迁移能力受损,滞留于斑块内,增加了斑块不稳定性,加速动脉粥样硬化病变的进展。目前研究表明动脉粥样斑块中巨噬细胞分泌的神经导向因子Netrin-1通过与巨噬细胞表面相应受体结合,可以抑制巨噬细胞迁出斑块,促进动脉粥样硬化的进展。但在动脉粥样硬化形成初期,血管内皮细胞表达的Netrin-1却被发现对动脉粥样硬化起到保护作用。     

Specific involvement of caspases in the differentiation of monocytes into macrophages

Caspases are cysteine proteases involved in apoptosis and cytokine maturation. In erythroblasts, keratinocytes, and lens epithelial cells undergoing differentiation, enucleation has been regarded as a caspase-mediated incomplete apoptotic process. Here, we show that several caspases are activated in human peripheral blood monocytes whose differentiation into macrophages is induced by macrophage colony-stimulating factor (M-CSF). This activation is not associated with cell death and cannot be detected in monocytes undergoing dendritic cell differentiation in the presence of interleukin-4 (IL-4) and granulocyte-macrophage colony-stimulating factor (GM-CSF). The mechanisms and consequences of caspase activation were further studied in U937 human monocytic cells undergoing phorbol ester-induced differentiation into macrophages. Differentiation-associated caspase activation involves the release of cytochrome c from the mitochondria and leads to the cleavage of the protein acinus while the poly(ADP-ribose)polymerase remains uncleaved. Inhibition of caspases by either exposure to the broad-spectrum inhibitor benzyloxycarbonyl-Val-Ala-(DL)-Asp-fluoromethylketone (z-VAD-fmk) or expression of the p35 baculovirus inhibitory protein or overexpression of Bcl-2 inhibits the differentiation process. In addition, z-VAD-fmk amplifies the differentiation-associated production of radical oxygen species in both phorbol ester-differentiated U937 cells and M-CSF-treated monocytes, shifting the differentiation process to nonapoptotic cell death. Altogether, these results indicate that caspase activation specifically contributes to the differentiation of monocytes into macrophages, in the absence of cell death.     

Vascular endothelial growth factor-C (VEGF-C) is a more specific risk factor for lymph node metastasis than VEGF-D in submucosal colorectal cancer

BACKGROUND/AIMS: It is useful to decide whether lymphatic involvement or lymph node metastasis exists before polypectomy or operation in submucosal colorectal cancer. Whether vascular endothelial growth factor-C (VEGF-C) or VEGF-D could predict lymph node metastasis and lymphatic involvement is uncertain. METHODOLOGY: Expression of the VEGF-C and VEGF-D in human submucosal colorectal cancers was investigated in paraffin-embedded stepwise sections by means of immunohistochemistry, and the correlation between immunohistochemical expression pattern and clinicopathological features was also evaluated. RESULTS: The results showed that VEGF-C overexpression correlated with lymphatic involvement (P = 0.01) and lymph node metastasis (P = 0.02), but VEGF-D overexpression did not correlate significantly. In multivariate analysis lymphatic invasion was the predictive factor (P = 0.0129), but VEGF-C positivity was not predictive (P = 0.3437). CONCLUSIONS: These results may suggest that VEGF-C is a more specific risk factor for lymph node metastasis than VEGF-D in submucosal colorectal cancer.     

Vascular endothelial growth factor C and D expression correlates with lymph node metastasis and poor prognosis in patients with resected esophageal cancer

Vascular endothelial growth factors C (VEGF-C) and D (VEGF-D) are important lymphangiogenic factors in human cancers. We studied the expression of VEGF-C and VEGF-D using immunohistochemistry in 73 resected esophageal cancer specimens, and correlated the results with patient clinicopathologic features and survival. High expression of VEGF-C was identified in 40 (54.7%) patients, and it correlated positively with histological grade (p=0.038), tumor stage (p=0.01), depth of tumor invasion (p=0.036) and lymph node metastasis (p=0.001). In 48 of 73 (65.7%) tumors, the VEGF-D protein was also expressed at high levels. VEGF-D immunoreactivity significantly correlated with tumor location (p=0.027), size of tumor (p=0.015), histological grade (p=0.02), depth of invasion (p=0.001) and lymph node metastasis (p=0.018). In logistic multivariate analysis, high expression of VEGF-C (OR 1.941, 95% CI 1.263-7.289, p=0.024) was associated with lymph node metastasis. Calculating the prognostic relevance revealed that both VEGF-C and VEGF-D correlated with decreased overall survival (p=0.01, p=0.003), disease free survival (p=0.02, p=0.006), and cancer-specific survival (p=0.03, p=0.005). In conclusion, our results suggest that high levels of both VEGF-C and VEGF-D proteins are associated with lymph node involvement, and that VEGF-C expression is an independent predictor of risk for lymph node metastasis in esophageal cancer. In locally advanced disease, overexpression of VEGF-C and VEGF-D may be useful in identifying patients who are more likely to have a poor prognosis even after curative resection.     

Strong induction of members of the chitinase family of proteins in atherosclerosis: chitotriosidase and human cartilage gp-39 expressed in lesion macrophages

Atherosclerosis is initiated by the infiltration of monocytes into the subendothelial space of the vessel wall and subsequent lipid accumulation of the activated macrophages. The molecular mechanisms involved in the anomalous behavior of macrophages in atherogenesis have only partially been disclosed. Chitotriosidase and human cartilage gp-39 (HC gp-39) are members of the chitinase family of proteins and are expressed in lipid-laden macrophages accumulated in various organs during Gaucher disease. In addition, as shown in this study, chitotriosidase and HC gp-39 can be induced with distinct kinetics in cultured macrophages. We investigated the expression of these chitinase-like genes in the human atherosclerotic vessel wall by in situ hybridizations on atherosclerotic specimens derived from femoral artery (4 specimens), aorta (4 specimens), iliac artery (3 specimens), carotid artery (4 specimens), and coronary artery (1 specimen), as well as 5 specimens derived from apparently normal vascular tissue. We show for the first time that chitotriosidase and HC gp-39 expression was strongly upregulated in distinct subsets of macrophages in the atherosclerotic plaque. The expression patterns of chitotriosidase and HC gp-39 were compared and shown to be different from the patterns observed for the extracellular matrix protein osteopontin and the macrophage marker tartrate-resistant acid phosphatase. Our data emphasize the remarkable phenotypic variation among macrophages present in the atherosclerotic lesion. Furthermore, chitotriosidase enzyme activity was shown to be elevated up to 55-fold in extracts of atherosclerotic tissue. Although a function for chitotriosidase and HC gp-39 has not been identified, we hypothesize a role in cell migration and tissue remodeling during atherogenesis.     

Vascular endothelial growth factor D (VEGF-D) is a ligand for the tyrosine kinases VEGF receptor 2 (Flk1) and VEGF receptor 3 (Flt4)

We have identified a member of the VEGF family by computer-based homology searching and have designated it VEGF-D. VEGF-D is most closely related to VEGF-C by virtue of the presence of N- and C-terminal extensions that are not found in other VEGF family members. In adult human tissues, VEGF-D mRNA is most abundant in heart, lung, skeletal muscle, colon, and small intestine. Analyses of VEGF-D receptor specificity revealed that VEGF-D is a ligand for both VEGF receptors (VEGFRs) VEGFR-2 (Flk1) and VEGFR-3 (Flt4) and can activate these receptors. However, VEGF-D does not bind to VEGFR-1. Expression of a truncated derivative of VEGF-D demonstrated that the receptor-binding capacities reside in the portion of the molecule that is most closely related in primary structure to other VEGF family members and that corresponds to the mature form of VEGF-C. In addition, VEGF-D is a mitogen for endothelial cells. The structural and functional similarities between VEGF-D and VEGF-C define a subfamily of the VEGFs.     

Dendritic cells in the arterial wall express C1q: potential significance in atherogenesis

OBJECTIVE: Dendritic cells (DCs) accumulate in atherosclerotic lesions but their characteristics and their role in atherogenesis are poorly understood. C1q, an element of the first component of complement, is expressed by interdigitating dendritic cells and follicular dendritic cells in the spleen. It has been suggested that C1q is involved in capturing immune complexes in the lymphoid tissue. Immune complexes are also detected in atherosclerotic lesions. The present study investigated whether C1q is expressed by DCs in the arterial wall. Because DCs accumulating within atherosclerotic lesions might originate from monocytes that infiltrate the intima from very early stages of atherosclerosis, C1q expression was also examined in monocyte-derived DCs in vitro. METHODS: Specimens of the aorta, carotid, mammary, popliteal and tibial arteries were obtained during operation. Expression of C1q in the arterial wall was studied by immunohistochemistry. The nature of cells expressing C1q was studied in sections double stained with antibodies to C1q and cell type specific markers including CD1a and S-100 (for identification of DCs), CD68 (macrophages), CD3 (T-cells), von Willebrand factor (endothelial cells), and smooth muscle alpha-actin (smooth muscle cells). In vitro, DCs were differentiated from human peripheral blood monocytes using GM-CSF and IL-4. Peripheral blood monocytes were differentiated to macrophages using M-CSF. The expression of C1q in monocytes and in vitro monocyte-derived DCs and macrophages was determined by RT-PCR, Western blotting, immunofluorescence microscopy and flow cytometry. RESULTS: In all the arterial specimens studied, DCs expressing C1q were detected. C1q was also found in macrophages, macrophage foam cells and in neovascular endothelial cells in atherosclerotic lesions, but no C1q expression was detected in T-cells and smooth muscle cells. In vitro analysis demonstrated that monocyte-derived DCs and macrophages express C1q but no C1q was detected in monocytes. CONCLUSION: C1q is expressed by DCs residing in the arterial wall as well as by monocyte-derived DCs in vitro. Expression of C1q occurs during differentiation of monocytes to DCs and macrophages and might be important in binding and trapping immune complexes in atherosclerotic lesions.     

胃癌组织中VEGF-C、VEGF-D、MMP-9的表达变化及意义

目的观察血管内皮生长因子（VEGF）C、D和基质金属蛋白酶MMP-9在胃癌组织中的表达及其意义。方法采用免疫组织化学染色检测108例胃癌手术切除标本中VEGF-C、D及MMP-9的表达情况,并以正常胃黏膜组织作为对照。结果VEGF-C、VEGF-D及MMP-9在胃癌组织中的阳性表达率分别为55．7％、77．8％、75．0％,而在正常胃黏膜的阳性表达率分别为15．0％、20．0％、10．0％,三者的表达率在两组问均有明显差异（P均〈0．05）。伴淋巴结转移的胃癌病例其VEGF-D及MMP-9阳性表达率（87．0％,83．3％）高于无淋巴结转移者（31．5％,33．3％）,P均〈0．05;而VEGF-C在两组的阳性表达率相近,P〉0．05。结论VEGF-D及MMP-9的表达与胃癌分期、淋巴结转移关系密切,有望成为胃癌治疗的新靶点。