尿酸对大鼠血管平滑肌细胞赖氨酰氧化酶和基质金属蛋白酶-2表达的影响

目的:研究尿酸对大鼠血管平滑肌细胞赖安酰氧化酶(LOX)和基质金属蛋白酶-2(MMP-2)表达的影响。方法:人工传代培养大鼠血管平滑肌细胞,分为对照组、尿酸组(20、40、60 mg/L尿酸干预48 h;40 mg/L尿酸干预24、48、72 h)、β氨基丙腈组(40 mg/L尿酸干预48 h后加入LOX的特异性抑制剂β氨基丙腈10 mg/ml孵育24 h)。用激光共聚焦显微镜观察细胞内活性氧情况。提取大鼠血管平滑肌细胞RNA和蛋白,用逆转录聚合酶链式反应和免疫印迹法测定LOX及MMP-2信使核糖核酸(mRNA)和蛋白的表达水平。结果:尿酸组大鼠血管平滑肌细胞增殖量、细胞内活性氧、LOX及MMP-2的m RNA和蛋白水平均明显高于对照组;与尿酸组相比,β氨基丙腈组大鼠血管平滑肌细胞LOX及MMP-2 mRNA和蛋白表达均明显下调,差异均有统计学意义(P均0.01)。结论:尿酸可上调大鼠血管平滑肌细胞LOX及MMP-2表达。     

尿酸减轻氧化应激诱导的血管内皮细胞损伤

目的　探讨尿酸对氧化应激情况下的人脐静脉内皮细胞（HUVEC）有无保护作用以及其可能的机制。方法　将人脐静脉内皮细胞分为四组：不做任何处理的对照组、单纯叔丁基过氧化氢（t-BHP）组、单纯尿酸组和尿酸+t-BHP组。MTT试验计算各组细胞存活率。DCFH-DA探针检测各组细胞内活性氧（ROS）水平。流式细胞仪检测各组细胞凋亡情况。荧光定量PCR技术检测各组细胞核转录相关因子2（Nrf2）mRNA表达变化。Western　blot　技术检测各组细胞胞浆与胞核中Nrf2蛋白表达水平。结果　MTT试验发现，尿酸+t-BHP组细胞存活率（78.5%±7.6%）显著高于单纯t-BHP组（P<0.05）。尿酸+t-BHP组细胞内ROS水平以及细胞凋亡率都明显低于单纯t-BHP组（P<0.05）。各组Nrf2的mRNA表达水平差异均无显著性（P>0.05），但单纯尿酸组与尿酸+t-BHP组细胞核内Nrf2明显增多。结论　尿酸对氧化应激下的血管内皮细胞具有保护作用，其机制可能为尿酸增加了血管内皮细胞中Nrf2的核内转移。     

TFPI基因转染对血管平滑肌细胞中细胞凋亡抑制蛋白的调控

目的研究组织因子途径抑制物(TFPI)基因转染对大鼠血管平滑肌细胞中细胞凋亡抑制蛋白(IAP)表达的影响,探讨TFPI诱导细胞凋亡的可能机制。方法将含有人TFPI基因的重组腺病毒或含β-半乳糖苷酶(LacZ)基因的重组腺病毒或DMEM在体外分别转染大鼠血管平滑肌细胞,用ELISA方法测定转染后细胞中TFPI蛋白的表达水平,用RT-PCR方法测定基因转染后不同时间点细胞中c-IAP1mRNA的表达,用Western-blot方法检测基因转染后不同时间点细胞中survivin的表达。结果基因转染后1天在血管平滑肌细胞中即可检测到TFPI蛋白表达,峰值出现在转染后第3天;基因转染后3天和7天,TFPI组c-IAP1 mRNA的表达与对照组相比明显减少(P0.05);基因转染后3、5、7天,TFPI组survivin的表达与对照组相比明显减少(P0.05),且具有明显的时间依赖性。结论 TFPI可能通过抑制IAP的表达来发挥诱导平滑肌细胞凋亡的作用,从而抑制冠状动脉介入治疗后再狭窄发生。     

蛋白激酶GIa基因在血性脑脊液致大鼠脑动脉平滑肌细胞增殖中的作用

目的 观察血性脑脊液对大鼠脑动脉平滑肌细胞蛋白激酶Gia mRNA及其蛋白表达水平变化与增殖的关系,探讨蛋白激酶Gla基因在蛛网膜下腔出血后继发慢性脑血管痉挛分子机制中的调控作用.方法 组织块法原代培养脑动脉平滑肌细胞.采用半定量逆转录多聚酶链反应技术检测对照组、血性脑脊液处理24 h组、血性脑脊液处理48 h组蛋白激酶Gia基因mRNA的表达水平;采用蛋白质印迹技术检测相应的蛋白的表达水平.采用甲基噻唑基四唑法、氚标记胸腺嘧啶核苷掺入法检测脑动脉平滑肌细胞增殖改变.结果 血性脑脊液诱导脑动脉平滑肌细胞不断增殖.各组均检测出蛋白激酶Gia基因的mRNA以及蛋白表达的变化,图像定量分析光密度值显示各组表达的mRNA以及蛋白表达与细胞增殖改变密切相关.结论 蛋白激酶Gia基因可能在蛛网膜下腔出血后脑血管痉挛中调节脑动脉平滑肌细胞增殖.     

HPS-1对人肺腺癌A549细胞凋亡诱导作用的机制研究

目的 评价HPS-1对人肺腺癌A549细胞凋亡蛋白Caspase 3、8、9以及Bax、Bcl-2mRNA表达的影响,探究HPS-1抗肺肿瘤可能机制.方法 人肺腺癌A549细胞经低、中、高剂量HPS-1处理不同时间后,噻唑蓝(MTT)法检测各组细胞的增殖情况,流式细胞术(FCM)法检测各组细胞凋亡率及细胞周期比例,比色法检测各组细胞凋亡蛋白Caspase-3、8、9的表达,RT-PCR法检测各组细胞Bax、Bcl-2 mRNA的表达.结果 MTT结果显示,低、中、高剂量HPS-1对人肺腺癌A549细胞的增殖具有明显抑制作用,且具有时间、剂量依赖性;FCM法检测发现,低、中、高剂量HPS-1对人肺腺癌A549细胞的凋亡具有促进作用,且与剂量呈正相关;比色法检测各组细胞发现,HPS-1促进凋亡蛋白Caspase-3、8、9的上调,且HPS-1高剂量组凋亡蛋白上调更明显.结论 HPS-1具有抑制人肺腺癌A549细胞增殖、诱导其凋亡作用,且该作用可能与HPS-1阻滞细胞周期G1期,上调凋亡蛋白Caspase-3、8、9及Bax mRNA表达,下调Bcl-2 mRNA表达有关.     

碱性成纤维细胞生长因子在烟草烟雾诱导大鼠血管平滑肌细胞增殖中的作用

目的探讨烟草烟雾提取物对大鼠血管平滑肌细胞增殖的影响及碱性成纤维细胞生长因子在其中的作用。方法按不同浓度烟草烟雾提取物(0、2.5%、5%、10%和20%)分为对照组、低浓度、中等浓度、高浓度和过高浓度烟草烟雾提取物组刺激血管平滑肌细胞,采用MTT法观察细胞增殖变化,免疫细胞化学法测定碱性成纤维细胞生长因子和增殖细胞核抗原蛋白的表达,同时用逆转录-聚合酶链反应法检测碱性成纤维细胞生长因子mRNA表达。用筛选出的最适烟草烟雾提取物浓度处理大鼠血管平滑肌细胞不同时间(0、4、8、12 h和24 h)后,检测碱性成纤维细胞生长因子mRNA及碱性成纤维细胞生长因子和增殖细胞核抗原蛋白的变化。用碱性成纤维细胞生长因子抗体和最适浓度烟草烟雾提取物干预血管平滑肌细胞24 h后检测细胞增殖及碱性成纤维细胞生长因子和增殖细胞核抗原蛋白表达的变化。结果 (1)与对照组相比,低浓度烟草烟雾提取物组(P0.05)和中浓度组血管平滑肌细胞增加明显(P0.01),而高浓度组和过高浓度组与对照组比较差异无显著性(P0.05)。碱性成纤维细胞生长因子mRNA、蛋白和增殖细胞核抗原蛋白在对照组中有少量表达,低浓度烟草烟雾提取物组表达增加(P0.01),中浓度烟草烟雾提取物组达到高峰,高浓度和过高浓度烟草烟雾提取物组仍高于对照组(P0.01)。(2)对照组(不加烟草烟雾提取物组即0 h组)血管平滑肌细胞中有少量碱性成纤维细胞生长因子mRNA、蛋白和增殖细胞核抗原蛋白表达。低浓度烟草烟雾提取物刺激4 h后细胞内碱性成纤维细胞生长因子mRNA、蛋白和增殖细胞核抗原蛋白表达增加(P0.01),碱性成纤维细胞生长因子mRNA于8 h达高峰;碱性成纤维细胞生长因子和增殖细胞核抗原蛋白于12 h达高峰。(3)碱性成纤维细胞生长因子抗体可显著抑制5%烟草烟雾提取物诱导的血管平滑肌细胞增殖和碱性成纤维细胞生长因子、增殖细胞核抗原蛋白表达增加。结论低浓度和中浓度烟草烟雾提取物对大鼠血管平滑肌细胞的促增殖作用逐渐增加;高浓度和过高浓度组时促增殖作用反而减弱。烟草烟雾提取物可能是通过增加碱性成纤维细胞生长因子的表达促进大鼠血管平滑肌细胞的增殖。     

阿司匹林对血管平滑肌细胞增殖及增殖细胞核抗原表达的影响

目的探讨阿司匹林对大鼠血管平滑肌细胞增殖的影响及相关机制。方法体外培养大鼠主动脉平滑肌细胞,用不同浓度的阿司匹林处理,并且设置对照组,采用MTT法检测阿司匹林对血管平滑肌细胞增殖活性的影响,用免疫细胞化学和逆转录聚合酶链反应检测阿司匹林作用后血管平滑肌细胞中增殖细胞核抗原的表达。结果较高浓度(5×10-3mol/L)的阿司匹林对血管平滑肌细胞的增殖有明显抑制作用(P<0.05),相对抑制率为31.5%。与对照组相比,该浓度组血管平滑肌细胞中增殖细胞核抗原的蛋白和mRNA表达量均显著降低(P<0.05)。结论阿司匹林可能通过降低增殖细胞核抗原的表达来抑制血管平滑肌的增殖,对心血管系统具有抗血小板聚集之外的保护作用。     

葛根素对血管平滑肌细胞增殖及Bcl-2蛋白和凝血酶受体mRNA表达的影响

目的观察葛根素对凝血酶诱导的血管平滑肌细胞增殖及Bcl-2蛋白和凝血酶受体mRNA表达的影响,旨在认识葛根素作用的分子机制。方法以细胞计数法和流式细胞仪DNA含量测定,细胞周期分析法观察凝血酶及葛根素对血管平滑肌细胞增殖和DNA合成的影响。凝血酶及葛根素等各处理因素作用24 h后,用免疫印迹法检测Bcl-2蛋白表达,以半定量逆转录聚合酶链反应检测凝血酶受体mRNA的表达。结果凝血酶对血管平滑肌细胞有明显促增殖作用,促增殖效应在24 h末达峰值,且凝血酶浓度在0.1~1.0 u/L之间有剂量依赖关系;葛根素呈剂量依赖性地抑制凝血酶诱导的细胞增殖、DNA合成及血管平滑肌细胞Bcl-2蛋白的表达;高浓度(1.5×10-3mol/L)葛根素可显著抑制凝血酶诱导的凝血酶受体mRNA上调。结论葛根素能抑制凝血酶诱导的血管平滑肌细胞增殖,这可能与其抑制Bcl-2蛋白有关,并部分与其抑制凝血酶受体mRNA表达有关。     

吡格列酮通过内质网应激致凋亡途径对大鼠血管平滑肌细胞钙化的影响

目的　探讨吡格列酮通过内质网应激致凋亡途径对大鼠血管平滑肌细胞钙化的影响及机制。方法　利用β-甘油磷酸钠联合丙酮酸钠制备钙化血管平滑肌细胞模型,予不同浓度（10、50、100　μmol/L）吡格咧酮干预。用Von　Kossa　染色、茜素红S染色测定钙含量以及碱性磷酸酶（ALP）活性观察细胞钙化程度。采用流式细胞术及Tunel法检测细胞凋亡率,实时荧光定量PCR及Western　Blot检测各组细胞GRP78、Caspase-12和Runx2的mRNA及蛋白表达。结果　钙化组其钙含量、ALP活性较对照组细胞增多（P<0.05）,而不同浓度吡格列酮呈剂量依赖性地减轻钙化大鼠血管平滑肌细胞的钙含量和ALP活性（P<0.05）;钙化组其细胞凋亡率较对照组明显升高,而不同浓度吡格列酮呈剂量依赖性地减轻钙化大鼠血管平滑肌细胞凋亡率（P<0.05）;钙化组GRP78、Caspase-12和Runx2　的mRNA及蛋白表达明显升高,而不同浓度吡格列酮呈剂量依赖性地下调钙化大鼠血管平滑肌细胞GRP78、Caspase-12和Runx2的mRNA及蛋白表达（P<0.05）。结论　吡咯列酮通过内质网应激致凋亡途径作用可减轻β-磷酸甘油诱导的血管平滑肌细胞钙化,其作用可能与GRP78、Caspase-12及Runx2表达下调有关。     

TGIF2对高糖诱导的血管内皮细胞生物学行为的影响

目的探讨同源异型结构域蛋白转化生长影响因子(TGIF)2对高糖诱导的血管内皮细胞生物学行为的影响。方法将培养的人脐静脉内皮(HUVECs)细胞分为对照组(未处理)、高糖组(葡萄糖处理)、空载体阴性对照质粒(NC)高糖组(葡萄糖+转染NC质粒)和TGIF2高糖组(葡萄糖+转染psiC HECK2-TGIF2 3'-UTR质粒),处理24 h和48 h后,以3-(4,5-二甲基噻唑-2)-2,5-二苯基四氮唑溴盐(MTT)法检测细胞增殖;处理48 h后,以RT-PCR和Western印迹检测各组细胞中TGIF2 mRNA和蛋白表达,Transwell法检测细胞迁移,流式细胞仪检测细胞凋亡。结果与对照组相比,高糖组、NC高糖组和TGIF2高糖组HUVECs细胞中TGIF2 mRNA和蛋白表达水平、细胞活力、迁移能力均显著降低,凋亡率显著升高(P0.05);与高糖组相比,TGIF2高糖组中TGIF2 mRNA和蛋白表达、细胞活力、迁移能力显著升高,细胞凋亡率显著降低(P0.05)。结论高糖诱导下,TGIF2在血管内皮细胞中表达下降,上调其表达对高糖诱导的血管内皮细胞增殖、迁移和凋亡具有一定的保护作用。     

血管平滑肌细胞表达牛磺酸转运体

牛磺酸是一种条件必须氨基酸,是细胞内高丰度的一种自由氨基酸。牛磺酸主要通过牛磺酸转运体（Taurine transporter,TAUT）摄入细胞。本研究探讨牛磺酸转运体在血管平滑肌细胞内的表达。通过RT-PCR,测定TAUT基因在血管平滑肌细胞mRNA的表达,利用Western blot和免疫组织化学方法检测TAUT在血管平滑肌细胞蛋白的表达。体外培养的大鼠血管平滑肌细胞和大鼠主动脉组织切片中血管平滑肌细胞均可表达TAUT。血管平滑肌细胞可转录及翻译TAUT。     

反义凝血酶受体基因序列对大鼠血管平滑肌细胞增殖的影响

为了研究凝血酶受体在血管平滑肌细胞增埴中的作用 ,探讨反义凝血酶受体基因序列对大鼠血管平滑肌细胞增殖的影响 ,通过培养SD大鼠胸主动脉血管平滑肌细胞 ,以3 H TdR掺入率作为评价反义凝血酶受体基因序列抑制血管平滑肌细胞增殖的指标 ;用反转录聚合酶链反应检测反义凝血酶受体基因序列抑制血管平滑肌细胞凝血酶受体mRNA的表达 ;用Western blot检测反义凝血酶受体基因序列抑制血管平滑肌细胞凝血酶受体蛋白质的表达 ;用3 H 肌醇掺入率检测反义凝血酶受体序列抑制血管平滑肌细胞磷酸肌醇代谢的影响。结果发现 ,反义凝血酶受体基因序列明显抑制血管平滑肌细胞的增殖 (与对照组相比 ,P <0 .0 5 ) ;明显抑制血管平滑肌细胞的凝血酶受体mRNA和蛋白的表达 ;明显抑制了血管平滑肌细胞磷酸肌醇代谢。提示反义凝血酶受体基因序列明显抑制血管平滑肌细胞的增殖 ;凝血酶受体反义序列明显抑制血管平滑肌细胞的增殖是通过抑制凝血酶受体基因的表达 (特别是通过抑制DNA、mRNA和蛋白的表达 ) ,抑制细胞内信号传递来完成     

Cartilage oligomeric matrix protein (thrombospondin-5) is expressed by human vascular smooth muscle cells

Cartilage oligomeric matrix protein (COMP/thrombospondin [TSP]-5) belongs to the thrombospondin gene family and is an extracellular glycoprotein found predominantly in cartilage and tendon. To date, there is limited evidence of COMP/TSP-5 expression outside of the skeletal system. The aim of the present study was to investigate the expression of COMP/TSP-5 in cultured human vascular smooth muscle cells and human arteries. COMP/TSP-5 mRNA and protein expression was detected in cultured human vascular smooth muscle cells with both Northern blotting and immunoprecipitation. Serum, as well as transforming growth factor (TGF)beta1 and TGF-beta3, stimulated COMP/TSP-5 mRNA expression. COMP/TSP-5 was detected in normal as well as atherosclerotic and restenotic human arteries with immunohistochemistry. The majority of COMP/TSP-5 was expressed in close proximity to vascular smooth muscle cells. In vitro attachment assays demonstrated strong adhesion of smooth muscle cells to COMP/TSP-5-coated surfaces, with the majority of cells spreading and forming stress fibers. In addition, COMP/TSP-5 supported the migration of smooth muscle cells in vitro. The present study shows that COMP/TSP-5 is present in human arteries and may play a role in the adhesion and migration of vascular smooth muscle cells during vasculogenesis and in vascular disease settings such as atherosclerosis.     

Vasculin,a novel vascular protein differentially expressed in human atherogenesis

Recent suppressive subtractive hybridization analysis on human atherosclerotic plaque-derived RNA revealed genes upregulated in plaques with a thrombus versus stable plaques. Clone SSH6, containing part of a putative open reading frame of an unknown protein, was further investigated. Full-length cDNA, coding for a 473-amino acid (aa) protein, was identified in a vascular smooth muscle cell (SMC) cDNA library. Bioinformatics suggested the presence of multiple SSH6 variants due to alternative splicing of exon 3. Multiple-tissue Northern blot analysis demonstrated a differential expression pattern of these variants, as a ubiquitously expressed SSH6 mRNA missing exon 3, was detected apart from a putative vascular SMC-specific form containing exon 3. Western blot analysis indicated a ubiquitous 35-kDa protein (SSH6-beta), in addition to a 45-kDa protein (vasculin), detected in the vascular wall and in plasma. Analysis of arteries displaying various stages of atherosclerosis indicated that the vasculin/SSH6-beta ratio increases throughout atherogenesis. Immunohistochemical analysis demonstrated cytoplasmic expression of SSH6 gene products in macrophages, endothelial cells, and SMCs. In summary, we identified a novel mRNA/protein, vasculin, in the arterial wall and plasma. The regulated expression of vasculin in plaques suggests a role in atherogenesis. Moreover, its presence in plasma opens perspectives for vasculin as a marker for atherosclerosis.     

致动脉粥样硬化不同因素对大鼠腹腔巨噬细胞和主动脉平滑肌细胞分泌表达Tenascin-C的影响

目的　观察一些致动脉粥样硬化因素对培养的大鼠腹腔巨噬细胞和主动脉平滑肌细胞分泌表达Tenascin C的影响。方法　体外分离培养大鼠腹腔巨噬细胞和主动脉平滑肌细胞 ,同步后分别加入不同刺激因子采用Westernbolt及逆转录聚合酶链反应 (RT PCR)的方法检测Tenascin C蛋白和mRNA水平表达。结果　Tenascin C在两种细胞的对照组中均不表达 ,低密度脂蛋白刺激组只有少量表达 ,其余各刺激组均呈高水平表达。加入氧化修饰低密度脂蛋白 (oxLDL) 2h后即有Tenascin C的表达 ,6h时达高峰 ,可持续到 2 4h。oxLDL与Tenascin C蛋白的表达呈明显的浓度依赖性。结论　oxLDL等致动脉粥样硬化刺激因子可在转录水平上调Tenascin C基因的表达 ,从而促进血管平滑肌细胞和巨噬细胞分泌表达高水平的Tenascin C ,这可能是动脉粥样硬化中Tenascin C沉积的主要原因     

Phenotype-related alteration in expression of natriuretic peptide receptors in aortic smooth muscle cells.

To elucidate the physiological and pathophysiological roles of the natriuretic peptide family in vascular smooth muscle cells, in which the natriuretic peptide family is implicated in growth inhibition as well as vasorelaxation, we have examined the phenotype-related expression of three kinds of natriuretic peptide receptors in rat aortic smooth muscle cells. The expression of natriuretic peptide receptors at the mRNA level was studied by Northern blot hybridization, and the expression at the protein level was determined by the cGMP production method and receptor binding assay. In intact aortic media, atrial natriuretic peptide (ANP)-A receptor mRNA and ANP-B receptor mRNA were detected, and the potency of cGMP production by ANP was at least two orders of magnitude stronger than that by C-type natriuretic peptide. Clearance receptor mRNA was undetectable, and only a small amount of the clearance receptor was detected by the binding assay in intact aortic media. By contrast, in cultured aortic smooth muscle cells at the first, fifth, and 17th passages, the ANP-B receptor mRNA level markedly increased; meanwhile, the expression of the ANP-A receptor mRNA became undetectable. C-type natriuretic peptide was one order of magnitude more potent than ANP in cGMP production in cultured aortic smooth muscle cells. The clearance receptor density and its mRNA level increased tremendously in these cultured cells. These results demonstrate that the marked phenotype-related alteration occurs in the expression of natriuretic peptide receptors in rat aortic smooth muscle cells.     

TIMP-4 is regulated by vascular injury in rats

The role of basement membrane-degrading matrix metalloproteinases (MMPs) in enabling vascular smooth muscle cell migration after vascular injury has been established in several animal models. In contrast, the role of their native inhibitors, the tissue inhibitors of matrix metalloproteinases (TIMPs), has remained unproven despite frequent coregulation of MMPs and TIMPs in other disease states. We have investigated the time course of expression and localization of TIMP-4 in rat carotid arteries 6 hours, 24 hours, 3 days, 7 days, and 14 days after balloon injury by in situ hybridization, immunohistochemistry, and Western blot analysis. TIMP-4 protein was present in the adventitia of injured carotid arteries from 24 hours after injury. At 7 and 14 days after injury, widespread immunostaining for TIMP-4 was observed throughout the neointima, media, and adventitia of injured arteries. Western blot analysis confirmed the quantitative increase in TIMP-4 protein at 7 and 14 days. In situ hybridization detected increased expression of TIMP-4 as early as 24 hours after injury and a marked induction in neointimal cells 7 days after injury. We then studied the effect of TIMP-4 protein on the migration of smooth muscle cells through a matrix-coated membrane in vitro and demonstrated a 53% reduction in invasion of rat vascular smooth muscle cells. These data and the temporal relationship between the upregulation of TIMP-4, its accumulation, and the onset of collagen deposition suggest an important role for TIMP-4 in the proteolytic balance of the vasculature controlling both smooth muscle migration and collagen accumulation in the injured arterial wall.     

Heparin-binding EGF-like growth factor induces expression of lectin-like oxidized LDL receptor-1 in vascular smooth muscle cells

Receptor-mediated endocytosis of oxidized LDL (Ox-LDL) has been implicated in lipid accumulation and vascular cell dysfunction. Lectin-like Ox-LDL receptor-1 (LOX-1) is highly inducible by proinflammatory cytokines, as well as angiotensin II and Ox-LDL in vitro. LOX-1 is expressed in macrophages and smooth muscle cells accumulated in the intima of advanced atherosclerotic plaques in vivo. Here we show that heparin-binding epidermal growth factor-like growth factor (HB-EGF), a potent mitogen for vascular smooth muscle cells, induces LOX-1 expression in cultured bovine aortic smooth muscle cells. HB-EGF (1-100 ng/ml) induced LOX-1 expression, which was peaked between 8 and 16 h after HB-EGF stimulation. HB-EGF-induced expression of LOX-1 was suppressed by ZD1839, an inhibitor of EGF receptor phosphorylation. Both MEK and p38 mitogen-activated protein kinase (MAPK) inhibitors significantly blocked LOX-1 upregulation induced by HB-EGF. Phosphatidylinositol 3-kinase (PI3K) inhibitors also blocked HB-EGF-induced LOX-1 expression. HB-EGF induced phosphorylation of ERK, p38 MAPK and Akt, which were suppressed by ZD1839. Upregulated expression of LOX-1 was associated with enhanced uptake of DiI-labeled Ox-LDL in smooth muscle cells. Taken together, HB-EGF can also act as an inducer of LOX-1 expression and play an integral role in foam cell transformation, cellular dysfunction, and proliferation of smooth muscle cells in atherogenesis.