Insulin activates vascular endothelial growth factor in vascular smooth muscle cells: influence of nitric oxide and of insulin resistance

BACKGROUND: We aimed to evaluate whether insulin influences vascular endothelial growth factor (VEGF) synthesis and secretion in cultured vascular smooth muscle cells (VSMCs) via nitric oxide (NO) and whether these putative effects are lost in insulin-resistant states. MATERIALS AND METHODS: In VSMC derived from human arterioles and from aortas of insulin-sensitive Zucker fa/+rats and insulin-resistant Zucker fa/fa rats incubated with different concentrations of human regular insulin with or without inhibitors of phosphatidylinositol 4,5-bisphosphate 3-kinase (PI3-K), mitogen-activated protein kinase (MAPK), nitric oxide synthase (NOS) and guanosine 3',5'cyclic monophosphate(cGMP)-dependent protein kinase (PKG), we measured protein expression (Western blot) and secretion (ELISA) of VEGF. RESULTS: We found that in VSMCs from humans and from insulin-sensitive Zucker fa/+rats, insulin increases VEGF protein expression and secretion, with mechanisms blunted by wortmannin and LY294002 (PI3-K inhibitors), PD98059 (MAPK inhibitor), L-NMMA (NOS inhibitor) and Rp-8pCT-cGMPs (PKG inhibitor). Also the NO donor sodium nitroprusside (SNP) and the cGMP analogue 8-Bromo-cGMP increase VEGF protein expression and secretion, with mechanisms inhibited by wortmannin and PD98059. The insulin effects on VEGF are impaired in VSMCs from Zucker fa/fa rats, which also present a reduced insulin ability to increase NO. CONCLUSIONS: In VSMCs from humans and insulin-sensitive Zucker fa/+rats: (i) insulin increases VEGF protein expression and secretion via both PI3-K and MAPK; (ii) the insulin effects on VEGF are mediated by nitric oxide. The insulin action on both nitric oxide and VEGF is impaired in VSMCs from Zucker fa/fa rats, an animal model of metabolic and vascular insulin-resistance.     

Human macrophages modulate the phenotype of cultured rabbit aortic smooth muscle cells through secretion of platelet-derived growth factor

Phenotypic change of aortic smooth muscle cells (SMC) is a key step for their abnormal proliferation in atheromatous lesions. In this study modulation of the growth properties of SMC by macrophages was investigated to clarify the mechanism regulating the SMC phenotype. Cultured rabbit SMC preincubated with either macrophages derived from human peripheral monocytes, or conditioned medium from macrophages grew faster than control SMC in the absence of either macrophages or conditioned medium. SMC preincubated with purified platelet-derived growth factor (PDGF) also grew faster than control SMC in the absence of PDGF, and their rapid growth was maintained for at least two passages. SMC preincubated with conditioned medium of macrophages plus anti-PDGF antibody did not grow faster than control SMC. Furthermore SMC preincubated with PDGF acquired the ability to secrete some mitogen, which differed from PDGF. These results suggest that macrophages modulate the phenotype of SMC by a mechanism mediated by PDGF. As a result the SMC grow faster and at the same time secrete some mitogen probably distinct from PDGF in an autocrine manner.     

Aggregated low density lipoprotein induces tissue factor by inhibiting sphingomyelinase activity in human vascular smooth muscle cells

Summary. Background: Our previous results demonstrated that aggregated low density lipoprotein (agLDL) induces tissue factor (TF) expression and activation through Rho A translocation in human vascular smooth muscle cells (VSMC). We also previously demonstrated that membrane sphingomyelin (SM) content is higher in agLDL‐exposed VSMC than in control cells. The main enzymes regulating cellular SM content are the family of sphingomyelinases (Smases) that hydrolize SM to phosphorylcholine and ceramide (CER). Objectives: We wished to investigate whether agLDL has the ability to modulate acidic‐ (A‐) and neutral (N‐) Smase activity and whether or not this effect is related to the upregulatory effect of agLDL on Rho A translocation and TF activation in human VSMC. Methods and Results: By measuring generated [¹⁴C]‐phosphorylcholine, we found that agLDL significantly decreased A‐Smase and specially N‐Smase activity. Pharmacological Smase inhibitors increased Rho A and TF. Specific loss‐of‐function of A‐Smase or N‐Smase 1 (N1‐Smase) by siRNA treatment (500 nmol L^?1, 12 hours) dramatically increased membrane Rho A protein levels (5‐ and 3‐fold, respectively). Concomitantly, TF protein expression and TF procoagulant activity were also increased. Inhibition of A‐Smase or N‐Smase activity by agLDL, siRNA‐anti A‐ or N1‐Smase or pharmacological treatment significantly increased the SM content of vascular cells. The inhibition of SM synthesis by fumonisin B₁ (FB₁) prevented the upregulatory effect of agLDL on TF. Conclusions: These results demonstrate that inhibition of both A‐ and N1‐Smase might explain the upregulatory effect of agLDL on TF activation, and suggest that this effect is related, at least in part, to membrane SM enrichment.     

Homocysteine induces connective tissue growth factor expression in vascular smooth muscle cells.

BACKGROUND: Increased homocysteine levels in blood might be an important risk factor for the development of cardiovascular diseases. Connective tissue growth factor (CTGF) was found to be involved in atherosclerotic plaque progression. So far, the possible connection between homocysteine and CTGF has not been studied. OBJECTIVE: This study was designed to test whether homocysteine could induce CTGF expression in vascular smooth muscle cells (VSMC). METHODS AND RESULTS: Hyperhomocysteinemia was induced in Sprague-Dawley rats after 4 weeks of a high-methionine diet. CTGF mRNA and protein expression was detected in the aortas isolated from hyperhomocysteinemic rats, but not in the controls. The underlying mechanism of homocysteine-induced CTGF expression was investigated in cultured human umbilical vein smooth muscle cells (HUVSMC). CTGF mRNA expression was induced after treatment with dl-homocysteine (50 micromol L(-1)) for 1 h, which remained at the elevated level for up to 8 h. CTGF protein level increased after homocysteine treatment for 8 h, and the elevated status was maintained for up to 48 h. Several intracellular signals elicited by homocysteine are involved in CTGF synthesis, including protein kinase C (PKC) activation and reactive oxygen species (ROS). Transfection HUVSMCs with a CTGF small interference RNA (siRNA) plasmid, which specifically inhibited the expression of CTGF, decreased extracellular matrix (ECM) accumulation caused by homocysteine. CONCLUSION: Our results demonstrate that homocysteine could increase the expression of CTGF in VSMC both in vivo and in vitro. The novel findings suggest that homocysteine might contribute to accelerated progression of atherosclerotic lesions by inducing CTGF expression.     

Lysyl oxidase enhances elastin synthesis and matrix formation by vascular smooth muscle cells

Lysyl oxidase (LOX) is a copper‐dependent enzyme that initiates covalent crosslinking of elastin precursors by oxidizing peptidyl lysine to aminoadipic semi‐aldehydes. Previous studies have shown LOX deficiency to affect crosslinking of elastin and collagen in vivo, resulting in disorganized connective tissue formation. In this study, we investigated the utility of exogenously supplemented LOX peptides (50–100 µl/well) to elastin synthesis, crosslinking efficiency and matrix deposition in adult rat aortic smooth muscle cell (RASMC) cultures. Additionally, we also examined the role of LOX peptides on SMC proliferation and matrix metalloproteinase (MMP) synthesis in these cultures. Highly purified bovine aorta LOX peptide was found to increase matrix elastin synthesis by 40–80% to that in control cultures in a dose‐dependent manner, while the crosslinking efficiency significantly (as measured by the ratio of matrix elastin protein to the total elastin protein synthesized) improved to 45–55% of total elastin synthesized under these conditions. However, LOX peptides affected neither SMC proliferation relative to controls, nor elastin precursor (tropoelastin) synthesis, nor the total elastin synthesis on a per‐cell basis. In general, LOX peptides also did not affect MMP‐2 and MMP‐9 activities relative to control cultures, except for MMP‐9 activity suppression at a higher LOX dose, suggesting that these LOX peptide cues could be safely used to enhance tropoelastin crosslinking into matrix structures and elastin matrix yield, within tissue‐engineered constructs, a major challenge in the field. Copyright © 2009 John Wiley & Sons, Ltd.     

双龙丸对兔主动脉粥样斑块内血管内皮生长因子和碱性成纤维细胞生长因子表达的影响

目的观察双龙丸对兔主动脉粥样硬化斑块内血管内皮生长因子 (VEGF)和碱性成纤维细胞生长因子 (bFGF)表达的影响。方法免疫损伤加高脂喂养建立兔动脉粥样硬化 (AS)模型 ,分为空白对照组 (Ⅰ组 ,6只 )、实验对照组 (Ⅱ组 ,6只 )、开搏通对照组 (Ⅲ组 ,6只 ,10mg/kg·d ,灌胃 12周 )和双龙丸组 (Ⅳ组 ,6只 ,2 5 2 g/kg·d ,灌胃 12周 )。免疫组织化学法定性和定量观察VEGF和bFGF在主动脉粥样斑块内表达。结果Ⅲ组和Ⅳ组VEGF和bFGF表达面积、密度和密度指数比Ⅱ组显著降低 (P <0 0 1) ;Ⅳ组VEGF表达面积、密度和密度指数比Ⅲ组显著降低 (P <0 0 1)。病理染色示 ,Ⅰ组内中膜未见泡沫细胞形成 ,无bFGF和VEGF黄染。Ⅱ组 ,粥样斑块内大量泡沫细胞形成 ,广泛淡黄染。Ⅲ组和Ⅳ组 ,内膜少量泡沫细胞形成 ,呈轻微淡黄染。结论双龙丸和开搏通一样 ,可通过抑制VEGF和bFGF在动脉粥样斑块内表达 ,延缓或逆转动脉粥样硬化进展。     

他汀类药物对高磷介导血管平滑肌细胞成骨细胞转分化和钙化的影响

目的探讨他汀类药物对高磷介导血管平滑肌细胞成骨细胞转分化和钙化的影响。方法将体外培养的人主动脉平滑肌细胞（HASMC）分成对照组（常规Medium 231培养基）、正常磷浓度组（Pi1.5mmol/L）和高磷组（Pi2.5mmmol/L）。Real-time PCR测定干预72h后细胞的核结合因子α（cbf α）和骨桥蛋白（OPN）水平,测定干预14d后上清液的钙浓度。HASMC在浓度为0.1umol/L的阿托伐他汀和2.5mmol/L的Pi培养基中共同孵育14d后,检测HASMC的钙含量。结果培养72h后,cbf-α在Pi 2.5mmol/L组的mRNA表达明显高于对照组[（50.02±0.38）vs（1.02±0.35）,P〈0.001],而Pi 1.5mmol/L组与对照组无明显差别[（1.07±0.15）vs（1.02±0.35）,P〉0.05]。Pi 2.5mmol/L组的OPN表达亦明显高于对照组[（14.62±0.35）vs（1.05±0.16）],而Pi 1.5mmol/L组与对照组无明显差别[（0.99±0.10）vs（1.05±0.16）]。高磷组钙含量明显高于对照组[（115±2.43）vs（4.08±0.32）,P〈0.001],而Pi 1.5mmol/L组与对照组相比无明显变化[（5.01±0.21）vs（4.08±0.32）,P〉0.05]。阿托伐他汀能使高磷诱导HASMC的钙沉积明显减少[（115±2.43）vs（58±2.65）ug/mg蛋白,P〈0.01]。结论高磷作用能明显增加HASMC的cbfα-1的表达,明显增加HASMC成骨细胞标志性蛋白OPN的表达,使HASMC向成骨细胞转分化,进而促进HASMC钙化;阿托伐他汀能抑制高磷诱导的HASMC的钙化作用。     

小鼠主动脉平滑肌细胞Robo4膜蛋白的提取

目的优化小鼠主动脉平滑肌细胞膜蛋白提取方法,获得高纯度的Rob04膜蛋白。方法高速离心法选择性地分离提取总膜蛋白,BCA法测定总膜蛋白含量,Western—Blot检测目的蛋白条带。结果成功提取总膜蛋白,总膜蛋白浓度达1．47μg／μL,Western-Blot检测出Rob04膜蛋白条带。结论该提取方法简单、可靠、快速,获得的膜蛋白纯度高,可用于Western—Blot后续试验。     

腺病毒介导的线粒体融合素基因-2诱导大鼠颈动脉球囊损伤后血管平滑肌细胞凋亡

目的研究腺病毒介导的线粒体融合素基因2(mitofusin2gene,Mfn2)对大鼠颈动脉球囊损伤后血管平滑肌细胞(vascularsmoothmusclecells,VSMCs)凋亡的影响。方法建立大鼠颈动脉球囊损伤模型,用携带大鼠Mfn2基因(rMfn2)的重组腺病毒Adv rMfn2GFP和含有绿色荧光蛋白基因的对照腺病毒Adv GFP分别感染球囊损伤动脉段,以磷酸缓冲液(PBS)作为未感染对照组,假手术组作为正常对照组,采用免疫组织化学方法检测外源基因表达水平;末端脱氧核苷酸转移酶介导的dUTP缺口末端标记法(TUNEL)检测凋亡细胞;Image Pro图像分析系统进行血管定量组织形态学分析。结果病毒感染后5d,免疫组织化学证实Adv rMfn2GFP组Mfn2蛋白表达水平明显;TUNEL染色显示,Adv rMfn2GFP组的VSMCs凋亡率明显高于PBS组和Adv GFP组,假手术组未见TUNEL阳性VSMCs(n=10,P<0.01);感染后21d,Adv rMfn2GFP组的血管内膜面积及内膜中膜面积比明显低于对照组(n=10,P<0.01)。结论高表达Mfn2基因可诱导大鼠颈动脉球囊损伤后血管平滑肌细胞凋亡。     

Protein kinase C‐δ mediates von Willebrand factor secretion from endothelial cells in response to vascular endothelial growth factor (VEGF) but not histamine

Summary. Background: Vascular endothelial growth factor (VEGF) and histamine induce von Willebrand factor (VWF) release from vascular endothelial cells. Protein kinase C (PKC) is involved in the control of exocytosis in many secretory cell types. Objectives: We investigated the role of PKC and the interactions between PKC and Ca²⁺ signaling in both VEGF‐induced and histamine‐induced VWF secretion from human umbilical vein endothelial cells (HUVECs). Results: Several PKC inhibitors (staurosporine, Ro31‐8220, myristoylated PKC peptide inhibitor and Go6983) block VEGF‐induced but not histamine‐induced VWF secretion. PKC‐α and novel PKCs (PKC‐δ, PKC‐ε, and PKC‐η), but not PKC‐β, are expressed in HUVECs. Both VEGF and histamine activate PKC‐δ. However, gene inactivation experiments using small interfering RNA indicate that PKC‐δ (but not PKC‐α) is involved in the regulation of VEGF‐induced but not histamine‐induced secretion. Both VEGF and histamine induce a rise in cytosolic free Ca²⁺ ([Ca²⁺]_c), but the response to VEGF is weaker and even absent in a significant subset of cells. Furthermore, VEGF‐induced secretion is largely preserved when the rise in [Ca²⁺]_c is prevented by BAPTA‐AM. Conclusions: Our study identifies striking agonist specificities in signal–secretion coupling. Histamine‐induced secretion is dependent on [Ca²⁺]_c but not PKC, whereas VEGF‐induced secretion is largely dependent on PKC‐δ and significantly less on [Ca²⁺]_c. Our data firmly establish the key role of PKC‐δ in VEGF‐induced VWF release, but suggest that a third, VEGF‐specific, signaling intermediate is required as a PKC‐δ coactivator.     

Heparanase induces tissue factor expression in vascular endothelial and cancer cells

BACKGROUND: Over-expression of tissue factor (TF) and activation of the coagulation system are common in cancer patients. Heparanase is an endo-beta-D-glucuronidase that cleaves heparan sulfate chains on cell surfaces and in the extracellular matrix, activity that closely correlates with cell invasion, angiogenesis and tumor metastasis. The study was undertaken to investigate the involvement of heparanase in TF expression. METHODS: Tumor-derived cell lines were transfected with heparanase cDNA and TF expression was examined. The effect of exogenous addition of active and inactive heparanase on TF expression and activity was studied in tumor cell lines and primary human umbilical vein endothelial cells. TF expression was also explored in heparanase over-expressing transgenic (Tg) mice. Blast cells were collected from acute leukemia patients and TF and heparanase expression levels were analyzed. RESULTS: Over-expression of heparanase in tumor-derived cell lines resulted in a 2-fold increase in TF expression levels, and a similar trend was observed in heparanase Tg mice in vivo. Likewise, exogenous addition of heparanase to endothelial or tumor-derived cells resulted in enhanced TF expression and activity. Interestingly, TF expression was also induced in response to enzymatically inactive heparanase, suggesting that this effect was independent of heparanase enzymatic activity. The regulatory effect of heparanase on TF expression involved activation of the p38 signaling pathway. A positive correlation between TF expression levels and heparanase activity was found in blasts collected from 22 acute leukemia patients. CONCLUSIONS: Our results indicate that in addition to its well-known function as an enzyme paving a way for invading cells, heparanase also participates in the regulation of TF gene expression and its related coagulation pathways.     

miR‐145 attenuates phenotypic transformation of aortic vascular smooth muscle cells to prevent aortic dissection

Background miR‐145 is closely related to vascular smooth muscle cells (VSMC) phenotype transformation; however, the regulatory mechanisms through which miR‐145 regulates the VSMC phenotype transformation under mechanical stretching are unclear. In this study, we evaluated the roles of miR‐145 in VSMCs subjected to mechanical stretching in aortic dissection (AD).MethodsThe expression of miR‐145 in the aortic vessel wall of model animals and patients with AD was analyzed by quantitative polymerase chain reaction. miR‐145‐related protein‐protein interaction networks and Wikipathways were used to analyze VSMC phenotypic transformation pathways regulated by miR‐145. We used gain‐ and loss‐of‐function studies to evaluate the effects of miR‐145 on VSMC differentiation under mechanical stretch induction and assessed whether Krüppel‐like factor 4 (KLF4) was regulated by miR‐145 in the aorta under mechanical stretch conditions.Results miR‐145 was abundantly expressed in the walls of the normal human aorta, but was significantly downregulated in animal models and the walls of patients with dissection. We found that contractile phenotype‐related proteins were downregulated in VSMCs subjected to mechanical stretching, whereas the expression of secreted phenotype‐related proteins increased. miR‐145 overexpression also downregulated contractile phenotype‐related proteins in VSMCs and suppressed upregulation of phenotype‐related proteins. Finally, under mechanical stretching, KLF4 expression was significantly increased in VSMCs, and overexpression of miR‐145 blocked this effect.ConclusionOur results confirmed that mechanical stretch‐induced phenotypic transformation of VSMCs to promote AD via upregulation of KLF4; this mechanism was regulated by miR‐145, which directly modulated KLF4 expression and VSMC differentiation.     

超声造影剂对血管平滑肌细胞增殖、迁移和凋亡的影响

目的探讨超声波联合超声造影剂对平滑肌细胞增殖、迁移和凋亡的影响.方法体外培养大鼠胸主动脉血管平滑肌细胞（VSMC）.采用MIT法、Millicell小室、Annexin V-FITC/PI双标染色和流式细胞仪,检测VSMC的增殖、迁移能力和凋亡,观察血小板衍生生长因子--BB（PDGF-BB）对VSMC增殖、迁移和凋亡的影响,频率1 MHz、声强0.3 W/cm^2的连续波超声联合声学造影剂辐照VSMC后上述指标的变化.结果PDGF-BB对VSMC的凋亡无影响,但可促进VSMC增殖和迁移.超声联合造影剂辐照VSMC 30 s即可显著抑制PDGF-BB所致的VSMC增殖（P〈0.05）,同时细胞凋亡比例显著增高（P〈0.01）,辐照60 s可显著抑制PDGF-BB所致的VSMC迁移（P〈0.05）,随着辐照时间延长,以上作用增强,辐照60 s时对VSMC增殖的抑制程度最强.结论低强度超声波辐照联合超声造影剂可抑制VSMC增殖、迁移,并促进细胞凋亡.     

超声联合微泡抑制血管平滑肌细胞增殖机制的研究

目的观察超声联合微泡对血管平滑肌细胞(VSMCs)周期分布及细胞周期调节蛋白激酶(CDK2)和抑制物p27表达的影响,探讨超声联合微泡抑制VSMCs增殖的作用机制。方法体外培养的VSMCs经血小板衍生生长因子-BB(PDGF-BB)刺激后,以低频连续波超声(频率1MHz、声强为0.3W/cm2)联合脂质微泡(1μl/ml)辐照VSMCs60s。分别用流式细胞仪、免疫细胞化学法检测细胞周期分布和细胞周期调控蛋白CDK2、p27的表达。结果与对照组比较,PDGF-BB刺激组细胞G0～G1期细胞比例下降而S期细胞比例增高(P<0.01),CDK2表达上调而p27表达降低(P<0.01);与PDGF-BB组相比,超声联合微泡组G0～G1期细胞比例增高,S期细胞比例降低(P<0.01),CDK2表达下调而p27表达增高(P<0.01)。结论超声联合微泡下调CDK2蛋白和上调p27蛋白的表达,阻滞细胞周期进程,可能是抑制VSMCs增殖的机制之一。     

低频超声对大鼠主动脉平滑肌细胞凋亡的作用

目的观察低频超声波对体外培养的大鼠主动脉平滑肌细胞（VSMCs）凋亡的影响。方法42.6kHz超声辐照大鼠主动脉平滑肌细胞,台盼蓝染色分析辐照后即刻细胞存活率,流式细胞仪观察24小时后细胞凋亡。结果低频超声辐照可以诱导培养的VSMCs凋亡,该作用在50秒内随辐照时间的增加有增加的趋势。结论低频超声在无明显杀伤细胞的情况下可在短时间内诱导培养的VSMCs凋亡,提示低频超声是一种潜在的治疗PCI术后再狭窄的手段。     

Parathyroid hormone stimulates the endothelial expression of vascular endothelial growth factor

Background We showed previously that parathyroid hormone (PTH) may stimulate the endothelial expression of pro‐atherosclerotic and pro‐inflammatory markers. Considering the impact of PTH on vasculature, we decided to evaluate its effect on mRNA and intra‐cellular protein expressions of endothelial vascular endothelial growth factor (VEGF) taking into account that VEGF may play a role in the pathogenesis of endothelial dysfunctions. Materials and methods Human umbilical vein cords endothelial cells (HUVEC) were stimulated for 24 h with 10^?12–10^?10 mol L^?1 PTH. The VEGF‐165 mRNA expression (critical in stimulating endothelial cell proliferation) was evaluated by RT/PCR and the intra‐cellular VEGF protein expression by flow cytometry. The pathways by which PTH may have an effect on VEGF expression were also evaluated. Results PTH (10^?10 mol L^?1) significantly increased VEGF‐165 mRNA expression (P < 0·05). The addition of 50 nmol L^?1 protein kinase C (PKC) and 10 µmol L^?1 protein kinase A (PKA) inhibitors significantly reduced the VEGF‐165 mRNA expression (P = 0·01). We also examined whether nitric oxide (NO) may be involved in the PTH‐induced stimulation of VEGF‐165 expression. Pre‐treatment of the cells with 200 µmol L‐nitro arginine methyl ester (L‐NAME, NO synthase inhibitor) was found to inhibit VEGF‐165 mRNA expression (P = 0·006). VEGF protein could not be detected in the medium of HUVEC but it was present in the cell cytoplasm. PTH had no significant effect on cytoplasmatic VEGF protein expression. Conclusion The stimulatory effect of PTH on endothelial VEGF‐165 mRNA expression is partly through PKC and PKA pathways and is also NO dependent.     

Decorin mimic promotes endothelial cell health in endothelial monolayers and endothelial–smooth muscle co‐cultures

Non‐specific cytotoxins, including paclitaxel and sirolimus analogues, currently utilized as anti‐restenotic therapeutics, affect not only smooth muscle cells (SMCs) but also neighbouring vascular endothelial cells (ECs). These drugs inhibit the formation of an intact endothelium following vessel injury, thus emphasizing the critical need for new candidate therapeutics. Utilizing our in vitro models, including EC monolayers and both hyperplastic and quiescent EC–SMC co‐cultures, we investigated the ability of DS–SILY₂₀, a decorin mimic, to promote EC health. DS–SILY₂₀ increased EC proliferation and migration by 1.5‐ and 2‐fold, respectively, which corresponded to increased phosphorylation of ERK‐1/2. Interestingly, IL‐6 secretion and the production of both E‐selectin and P‐selectin were reduced in the presence of 10 μm DS–SILY₂₀, even in the presence of the potent pro‐inflammatory cytokine platelet‐derived growth factor (PDGF). In hyperplastic and quiescent EC–SMC co‐cultures, DS–SILY₂₀ treatment reduced the secretion of IFNγ, IL‐1β, IL‐6 and TNFα, corresponding to a 23% decrease in p38 phosphorylation. E‐selectin and P‐selectin expression was further reduced following DS–SILY₂₀ treatment in both co‐culture models. These results indicate that DS–SILY₂₀ promotes EC health and that this decorin mimic could serve as a potential therapeutic to promote vessel healing following percutaneous coronary intervention (PCI). Copyright © 2015 John Wiley & Sons, Ltd.     

同型半胱氨酸刺激动脉平滑肌细胞的初步研究

目的观察不同分型及不同浓度的同型半胱氨酸(Hcy)刺激动脉平滑肌细胞的结果,揭示高同型半胱氨酸血症致动脉粥样硬化的作用机制。方法对大鼠动脉平滑肌细胞进行体外原代培养,在培养中加入不同型及不同浓度的同型半胱氨酸进行对平滑肌细胞刺激,然后用MTT比色方法,观察平滑肌细胞的增殖情况。结果经单因素方差分析,DHcy促进平滑细胞的增殖与对照组之间没有显著性差异。D,LHcy与LHcy在一定浓度时,与对照组之间存在明显差异(P<001)。DHcy、D,LHcy、LHcy在促进平滑肌细胞增殖方面,经双因素方差分析,只有D,LHcy及LHcy之间存在显著差异(P<005)。结论大鼠动脉平滑肌细胞的增殖程度与D,LHcy及LHcy的水平呈正相关,而DHcy促进平滑肌细胞增殖作用不明显。LHcy促进平滑肌细胞增殖的程度与D,LHcy之间差异没有显著性,与DHcy之间存在显著性差异。     

人髓性白血病细胞VEGF及其受体的检测

目的 建立人髓性白血病细胞血管内皮生长因子（vascular endothelial growth factor,VEGF）及其受体KDR和Flt-1在基因转录和蛋白质水平上的检测方法,为临床判断白血病患者的预后提供技术支持。方法 用RT-PCR测定K562和HL-602种白血病细胞VEGF及其受体mRNA表达,免疫组织化学染色法检测VEGF及其受体蛋白表达;ELISA法检测细胞上清液中VEGF的分泌水平。结果 2种髓系白血病细胞均检测到VEGF的基因转录和蛋白表达。HL-60细胞同时表达Fh-1和KDR2种受体,而K562细胞仅有受体Flt-1的表达,未见受体KDR的mRNA和蛋白表达。细胞培养上清液中检出VEGF的高分泌。结论 VEGF及其受体在髓性白血病细胞表达增高,但不同细胞系VEGF受体表达有差异。VEGF及其受体在白血病的发生、发展中可能起重要作用。