腺苷对人静脉内皮细胞增殖的影响

目的探讨腺苷对人脐静脉内皮细胞（human umbilical vein endothelial cell，HUVEC）增殖的影响。方法MTT法观察腺苷的最佳作用浓度及最佳作用时问。结果4％FBS浓度下，腺苷具有明显的促HUVEC增殖作用，为最佳浓度。在10-^4 mol／L腺苷终浓度对细胞增殖有明显的促进作用，为最佳腺苷浓度。腺苷的促生艮作用在24h即出现，在48h已达到较高水平。结论在血供基本被阻断或血流基本正常的情况下，腺苷可能对细胞增殖尤影响；但在m流减少的情况下，腺苷的应用可以促进内皮细胞增殖，可能对血管新生有启动作用。     

Influence of carboxylic acid functionalization on the cytotoxic effects induced by single wall carbon nanotubes on human endothelial cells (HUVEC)

A vast variety of nanomaterials have been developed in the recent years, being carbon nanotubes (CNTs) the ones that have attracted more attention, due to its unique properties which make them suitable for numerous applications. Consequently, it is predicted that tons of CNTs will be produced worldwide every year, being its exposure of toxicological concern. Nanomaterials, once into the body, can translocate from the uptake sites to the blood circulation or the lymphatic system, resulting in distribution throughout the body. Thus, the vascular endothelium can be in contact with them and can suffer from their toxic effects. In this regard, the aim of this work was to investigate the cytotoxicity of single-walled carbon nanotubes (SWCNTs) on human endothelial cells evaluating the influence of acid carboxylic functionalization and also the exposure time (24 and 48 h). Biomarkers assessed were neutral red uptake, protein content, a tetrazolium salt metabolization and cell viability by means of the Trypan blue exclusion test. Cells were exposed to concentrations between 0 and 800 μg/mL SWCNTs for 24 and 48 h. Results have shown that both SWCNTs and carboxylic acid functionalized single-walled carbon nanotubes (COOH-SWCNTs) induce toxic effects in HUVEC cells in a concentration- and time-dependent way. Moreover, the carboxylic acid functionalization results in a higher toxicity compared to the SWCNTs.     

疡愈涂剂对人白细胞与血管内皮细胞黏附影响的分子机制

目的研究疡愈涂剂(YangYuTuJi,YYTJ)对白细胞与血管内皮细胞黏附影响的分子机制,探讨其促进皮肤创伤愈合的机制。方法用虎红染色法观察YYTJ高(132.5mg/L)、中(66.3mg/L)、低(33.2mg/L)浓度对中性粒细胞(polymorphonuclear,PMN)、人单核细胞(THP-1)与肿瘤坏死因子(tumor necrosis factor,TNF)诱导的人脐静脉内皮细胞(human umbilical vein endothelial cells,HUVEC)黏附的影响,用荧光免疫细胞化学法观察YYTJ对HUVEC表面细胞间黏附分子-1(inter cell ularadhesion molecule-1,ICAM-1)、血管细胞黏附分子-1(vascular cell adhesion molecule-1,VCAM-1)和CD44表达的影响。结果 YYTJ和TNF共同作用HUVEC12h后,高浓度YYTJ能明显抑制HUVEC与PMN以及THP-1黏附(P<0.05),能明显抑制HUVEC表面ICAM-1和CD44表达(P<0.05)。中浓度YYTJ能明显抑制HUVEC表面VCAM-1和CD44表达(P<0.05,P<0.01)。低浓度YYTJ能明显降低HUVEC表面CD44表达(P<0.05)。结论疡愈涂剂通过降低TNF诱导的HUVEC表面黏附分子的表达,抑制白细胞与血管内皮细胞的黏附,从而抑制过度的炎性反应。     

Expression and function of vascular endothelial growth factor receptors (Flt-1 and Flk-1) in vascular adventitial fibroblasts

Vascular endothelial growth factor receptors (VEGFRs) are previously considered to exist exclusively in endothelial cells. However, little is known if the receptors are expressed in other non-endothelial cells. In this study, we measured activation of two VEGFRs, Flk-1 and Flt-1, and their biological functions in cultured adventitial fibroblasts and injured rat carotid injury arteries induced by balloon angioplasty. Our results indicated that Flt-1, but not Flk-1, existed in adventitial fibroblasts. Angiotensin II increased Flt-1 protein expression in a time- and concentration-dependent manner. Adventitial fibroblast migration stimulated by vascular endothelial growth factor (VEGF) and placental growth factor (PIGF) required Flt-1 expression. The Flt-1-induced adventitial fibroblast migration was blocked by anti-Flt-1 neutralizing antibody and soluble VEGFR1 protein (sFlt-1). However, Flt-1 activation did not enhance cell proliferation. In addition, Flt-1 expression was significantly increased in the neointima and adventitia in injured rat carotid arteries. We concluded that functional expression of Flt-1 in adventitial fibroblasts might be an important mediator in the pathogenesis of vascular remodeling after arterial injury.     

Calycosin protects HUVECs from advanced glycation end products-induced macrophage infiltration

Ethnopharmacological relevance

Astragali radix is a traditional Chinese medicine that has long been used for treatment of diabetes and diabetes-associated disease, but its active component and mechanism on the disease is not well defined.

Aim of the study

Infiltration of leukocytes within the glomeruli and vasculature is one of the early and characteristic features of diabetic nephropathy. Advanced glycation end products (AGEs) play pivotal role in the progression of diabetic-associated diseases. The present study was designed to explore the therapeutic effect of calycosin, an active component from A. radix, on AGEs-induced macrophages infiltration in HUVECs.

Materials and methods

Transwell HUVEC-macrophage co-culture system was established to evaluate macrophage migration and adhesion. Immunocytochemistry was applied to examine TGF-beta1, ICAM-1 and RAGE protein expressions; real-time PCR was carried out to determine mRNA expression of TGF-beta1, ICAM-1 and RAGE. Immunofluorescence was carried out to observe estrogen receptor-alpha, ICAM-1, RAGE expression and the phosphorylation status of ERK1/2 and NF-κB.

Results

Calycosin significantly reduced AGEs-induced macrophage migration and adhesion to HUVEC. Pre-treatment with calycosin strikingly down-regulated HUVEC TGF-beta1, ICAM-1 and RAGE expressions in both protein and mRNA levels. Furthermore, calycosin incubation significantly increased estrogen receptor expression and reversed AGEs-induced ERK1/2 and NF-κB phosphorylation and nuclear translocation in HUVEC, and this effect of calycosin could be inhibited by estrogen receptor inhibitor, ICI182780.

Conclusions

These findings suggest that calycosin can reduce AGEs-induced macrophage migration and adhesion to endothelial cells and relieve the local inflammation; furthermore, this effect was via estrogen receptor-ERK1/2-NF-κB pathway.     

芎芍胶囊对人脐静脉内皮细胞分泌血管新生因子的影响

目的探讨芎芍胶囊对人脐静脉内皮细胞（HUVEC）分泌血管新生因子影响的机制。方法采用血清药理学和体外干预培养HUVEC的方法,通过MTF法和酶联免疫吸附分析法观察芎芍胶囊低、中、高剂量对HUVEC的体外增殖和分泌Ang、Ang-2、VEGF、bFGF、EGF和TGF-β1的影响。结果芎芍胶囊各剂量组均有促HUVEC增殖的作用。低剂量组有促进HUVEC分泌Ang、Ang-2、EGF和VEGF的作用,而对bFGF、TGF-β1分泌的影响无明显差异;中剂量组有促进HUVEC分泌Ang、Ang-2、EGF和bFGF的作用,抑制TGF-β1的分泌,对VEGF的分泌无明显影响;高剂量组有促进HUVEC分泌Ang、EGF和bFGF的作用,并抑制VEGF与TGF-β1的分泌,而对Ang-2的影响无明显差异。结论芎芍胶囊能促进HUVEC的增殖,增加HUVEC分泌促血管新生因子和降低抑血管生成因子表达,且与剂量有一定的关系。     

Heterogeneous glycosylation patterns of human PAI-1 may reveal its cellular origin

The main inhibitor of intravascular fibrinolysis is plasminogen activator inhibitor 1 (PAI-1) which binds to and irreversibly inhibits tissue plasminogen activator (tPA). PAI-1 is present in blood, both in platelets and in plasma, and PAI-1 levels are associated with risk of atherothrombosis. Several tissues express PAI-1 but the source of plasma PAI-1 is not known. We recently found that platelets can de novo synthesize PAI-1 and the amount synthesized in vitro in 24 hours is 35-fold higher than required to maintain normal plasma levels. Recombinant human PAI-1 expressed in different cell types or secreted naturally by human cell lines, exhibit heterogeneous glycosylation patterns. The aim of this study was to investigate the hypothesis that platelets might be the source of plasma PAI-1 and that the cellular source of PAI-1 can be determined by its tissue-specific glycosylation pattern. PAI-1 was isolated from platelets, macrophages, endothelial cells, adipose tissue, as well as plasma from lean and obese subjects. The glycosylation was analyzed by nanoLC-MS/MS. PAI-1 isolated from cell lysates and conditioned media from macrophages, endothelial cells, and adipose tissue expressed heterogeneous glycosylation patterns. By contrast, no glycans were detected on PAI-1 isolated from plasma or platelets from healthy lean individuals. Hence, our data suggest that platelets may be the main source of plasma PAI-1 in lean individuals. Interestingly, plasma PAI-1 from obese subjects had a glycan composition similar to that of adipose tissue suggesting that obese subjects with elevated PAI-1 levels may have a major contribution from other tissues.     

Treatment of endothelium with the chemotherapy agent vincristine affects activated protein C generation to a greater degree in newborn plasma than in adult plasma

INTRODUCTION: Activated protein C (APC) is well-established as a physiologically important anticoagulant. During development, plasma concentrations of protein C and alpha(2)macroglobulin, factors involved in APC generation, differ from adult levels. Chemotherapy drugs can perturb endothelial expression of PC-activating receptors. This study examines the effect of chemotherapy treatment of endothelium on APC generation in newborn and adult plasma. MATERIALS AND METHODS: APC generations were initiated on endothelial cells treated with vincristine or media by recalcifying defibrinated plasma with buffer containing thromboplastin. APC generation was terminated by mixing timed subsamples into FFRCMK-EDTA or heparin, followed by EDTA. APC-PCI and APC-alpha(1)AT were assayed by ELISA. APC-alpha(2)M was measured chromogenically. Since heparin converts free APC to APC-PCI, the difference between APC-PCI detected in heparin subsamples and APC-PCI detected in FFRCMK-EDTA subsamples gave the free APC. Cellular expression of EPCR and TM were measured by flow cytometry and Western blot. RESULTS: Vincristine-treated endothelium decreased free APC generation in newborn plasma to a greater degree than in adult plasma. APC-PCI levels in both adult and newborn plasma were unaffected by chemotherapy. Vincristine treatment reduced levels of APC-alpha(1) AT and APC-alpha(2) M to a greater degree in newborn plasma versus adult plasma. Expression of EPCR was reduced in cells treated with vincristine. Conversely, TM was reduced on the cell surface, but increased in whole cell lysates. CONCLUSIONS: The differential response of newborn and adult plasma PC components to chemotherapy-mediated changes in cell surface components may be a factor in the increased risk of thrombosis in children receiving chemotherapy.