ADM和ADT对肺动脉平滑肌细胞胶原合成及磷酸化ERK1/2表达的影响

目的: 检测不同浓度的肾上腺髓质素(ADM)和肾上腺加压素(ADT)对培养的Wistar大鼠肺动脉平滑肌细胞(PASMCs)Ⅰ、Ⅲ型胶原合成和磷酸化细胞外信号调节激酶(p-ERK1/2)表达的影响,探讨PASMCs增殖过程中ERK途径是否被激活。方法: 取健康雄性Wistar大鼠,行大鼠远端PASMCs分离并进行原代培养,采用小鼠抗人平滑肌α-actin单克隆抗体对培养细胞进行鉴定;在培养基内分别加入10^-7 mol/L ADM或ADT培养72 h 后加入兔抗大鼠Ⅰ型、Ⅲ型胶原抗体和兔抗大鼠p-ERK1/2抗体,0.01 mol/L PBS作阴性对照,FITC标记山羊抗兔IgG为Ⅱ抗,免疫荧光法观察PASMCs内Ⅰ、Ⅲ型胶原及p-ERK1/2表达。Western blotting检测10^-7mol/L、10^-8mol/L和10^-9 mol/L ADM或ADT对p-ERK1/2蛋白表达的影响。结果: 经平滑肌α-actin单克隆抗体对培养细胞进行鉴定,其纯度达97%。10^-7 mol/L ADM可抑制PASMCsⅠ、Ⅲ型胶原及p-ERK1/2的表达(P<0.05,P<0.01);10^-7 mol/L的ADT刺激后大鼠PASMCsⅠ、Ⅲ型胶原及p-ERK1/2的表达增强(P＜0.05,P<0.01)。Western blotting结果显示ADM可呈剂量依赖性抑制p-ERK1/2蛋白表达(P<0.01,P<0.05);而ADT也可呈剂量依赖性促进p-ERK1/2蛋白表达(P<0.01,P<0.05)。结论: ADM可抑制大鼠PASMCsⅠ、Ⅲ型胶原及p-ERK1/2表达,而ADT可促进PASMCsⅠ、Ⅲ型胶原及p-ERK1/2表达,提示PASMCs增殖过程中ERK通路被激活,ADM和ADT可能通过ERK1/2信号通路来调节PASMCs增殖。     

活性氧和ERK1/2信号通路在缺氧大鼠肺动脉平滑肌细胞增殖和凋亡中的作用

目的：研究缺氧状态下大鼠肺动脉平滑肌细胞（PASMCs）内活性氧（ROS）水平的变化,ROS对细胞外信号调节激酶（ERK）1/2蛋白表达的影响以及ROS和ERK1/2在PASMCs增殖和凋亡关系失衡中的作用。方法: 原代培养正常大鼠PASMCs,选用第2-3代用于实验。分别在常氧及缺氧条件下用ROS清除剂tiron、ERK1/2抑制剂PD98059进行分组干预。通过NBT还原法和DCFH-DA荧光探针检测细胞内ROS,免疫荧光法检测磷酸化- ERK1/2（p-ERK1/2）蛋白表达,MTT比色法和增殖细胞核抗原（PCNA）蛋白的免疫细胞化学法检测细胞增殖,原位末端标记法（TUNEL）检测细胞凋亡。结果: (1)缺氧组细胞内ROS水平明显高于对照组（P<0.01）;(2)缺氧组的增殖活性与对照组相比显著增高（P<0.01）,而凋亡率显著降低（P<0.01）,使用tiron后能明显抑制缺氧诱导的细胞增殖（P<0.05）,而凋亡率却明显升高（P<0.01）;(3)缺氧组p-ERK1/2蛋白表达显著高于对照组（P<0.01）,使用tiron后缺氧诱导的p-ERK1/2表达被显著抑制（P<0.01）;(4)使用PD98059也能明显抑制缺氧诱导的细胞增殖（P<0.05）,而凋亡率也明显升高（P<0.01）,缺氧下同时使用PD98059和tiron与单用tiron相比,对细胞增殖和凋亡的影响均无明显差异（P>0.05）。结论: 缺氧时PASMCs中生成增多的ROS通过活化下游ERK1/2信号通路,促进PASMCs增殖并抑制凋亡,从而在缺氧性肺动脉重建过程中发挥重要作用。     

FHL1在香烟烟雾刺激的大鼠肺动脉平滑肌细胞增殖与迁移中的作用

 目的：研究FHL1 (four-and-a-half LIM domain 1)在香烟烟雾提取物（CSE）刺激的大鼠远端肺动脉平滑肌细胞（PASMCs）增殖及迁移中的作用。方法：原代培养PASMCs,分别予CSE及FHL1 siRNA转染干预,分为6组：空白组、阴性转染组、FHL1 siRNA转染组、CSE组、CSE+阴性转染组和CSE+FHL1 siRNA转染组。Real-time PCR法检测FHL1 mRNA的表达,Western blotting法检测FHL1 蛋白,CCK-8法检测细胞增殖,Transwell 法测定细胞迁移。结果：CSE刺激导致PASMCs增殖、迁移及FHL1蛋白表达增加 (P<0.01) ,但FHL1 mRNA的表达无明显改变（P＞0.05）。FHL1 siRNA转染PASMCs,可降低CSE所致的PASMCs增殖及迁移(P<0.01)。结论：CSE可促进PASMCs增殖与迁移以及FHL1蛋白的表达, 抑制FHL1蛋白的表达可减弱CSE对PASMCs增殖和迁移的作用。这些结果表明CSE促进PASMCs增殖和迁移与FHL1蛋白有关。     

瞬时感受器电位香草酸受体1参与低氧性人肺动脉平滑肌细胞系的增殖

 目的 探讨低氧培养的人肺动脉平滑肌细胞系中瞬时感受器电位香草酸受体1的表达及功能改变,。方法 用RT-PCR、Real-time PCR和Western blot检测人肺动脉平滑肌细胞中TRPV1的表达。用细胞计数法检测细胞增殖。结果 低氧能明显上调人肺动脉平滑肌细胞中TRPV1通道的mRNA和蛋白的表达,并促进增殖, TRPV1通道阻断剂 Capsazepine呈剂量依赖性地抑制增殖。结论 TRPV1通道可能参与或调制低氧所致细胞增殖。     

钙敏感受体在缺氧诱导的大鼠肺动脉平滑肌细胞增殖中的作用

目的:观察钙敏感受体(CaSR)在缺氧诱导的大鼠肺动脉平滑肌细胞增殖中的作用。方法:Ⅱ型胶原酶消化法提取、培养大鼠肺动脉平滑肌细胞。应用Western blotting技术及免疫荧光染色分析CaSR蛋白在肺动脉平滑肌的表达;采用激光共聚焦扫描技术检测不同处理因素对细胞内钙离子浓度([Ca2+]i)的影响,应用MTT法分析不同处理因素对细胞存活率的影响。结果:大鼠肺动脉平滑肌细胞有CaSR蛋白表达。缺氧能够增加CaSR和增殖细胞核抗原(PCNA)的表达、细胞存活率及[Ca2+]i(与对照组比较,P0.05)。GdCl3(CaSR激动剂)能够增强缺氧的上述作用,NPS2390(CaSR抑制剂)则能够减弱缺氧的作用。结论:缺氧诱导的CaSR表达增加参与了缺氧性肺动脉平滑肌细胞增殖。     

慢性吸烟大鼠肺动脉平滑肌细胞钾通道Kv1.5、BKCa表达的变化

目的：观察吸烟对大鼠肺动脉平滑肌大电导的钙激活的钾通道（BK_Ca）和电压依赖性延迟整流钾通道Kv1.5蛋白和mRNA表达的影响，以阐明吸烟引起的肺血管反应性改变中钾通道表达的变化。方法：复制大鼠的慢性吸烟模型，采用HE染色、免疫组织化学染色、原位杂交等方法。结果：（1）慢性吸烟可降低大鼠肺动脉平滑肌 BK_Ca 蛋白和mRNA表达；（2）慢性吸烟可降低大鼠肺动脉平滑肌Kv1.5蛋白和mRNA表达；（3）大动脉 BK_Ca的降低程度大于Kv1.5，小动脉 BK_Ca和Kv1.5的降低程度无明显差异。结论：慢性吸烟可下调大鼠肺动脉平滑肌钾通道 BK_Ca和Kv1.5的表达水平，是导致肺血管反应性增高的机制之一。     

低氧对大鼠肺动脉平滑肌细胞血红素加氧酶-1 mRNA 表达及细胞增殖的影响

探讨血红素加氧酶－1（HO－1）mRNA在低氧大鼠肺动脉平滑肌细胞（PASMC0的表达及HO－1／一氧化碳（HO－1／CO）体系对PASMC增殖的影响。应用荧光定量RT－PCR法测定HO－1mRNA表达。用双波长法检测碳氧血红蛋白（HbCO)吸光值。应用免疫细胞化学方法检测细胞增殖核抗原（PCNA）及核转录因子－κB（NF-κB）的表达。发现HO－1 mRNA在常氧大鼠PASMC有低水平的表达，低氧12h HO-1mRNA水平是常氧时的1．5倍，且HbCO产量随之显著增高（P＜0．01）；低氧24h HO-1 mRNA表达呈回落趋势，HbCO产量亦有所减少，但两者仍高于常氧水平。低氧12h及24h PASMC PCNA核阳性反应颗粒表达较常氧时增强（P＜0．01，P＜0．001），使用HO抑制剂ZnPP-9，其PCNA该阳性反应颗粒表达较单纯低氧时增加更多（P＜0．001，P＜0．01）。低氧组核NF－κB阳性染色较常氧组增强（P＜0．001），使用ZnPP-9，其表达则比低氧时更多（P＜0．01）。低氧通过诱导大鼠PASMC的HO－1 mRNA基因表达，上调HO／CO体系活性，使内源性CO含量增高，抑制PASMC增殖；NF－κB参与了PASMC增殖的调控机制。     

Neonatal pulmonary hypertension prevents reorganisation of the pulmonary arterial smooth muscle cytoskeleton after birth

The pulmonary arterial smooth muscle cell (SMC) cytoskeleton was studied in tissue from 36 piglets aged from within 5 min of birth to 21 d of age, and in 8 adults. An additional 16 piglets were made pulmonary hypertensive by exposure to hypobaric hypoxia (50.8 kPa) for 3 d. In conduit intrapulmonary elastic arteries α, β and γ actin, the 204, 200 and 196 kDa myosin heavy chain (MHC) isoforms and vinculin were localised by immunohistochemistry. The total actin content, the proportion of monomeric to filamentous α and γ actin and changes in the proportions of the MHC isoforms were determined biochemically. Dividing SMCs were localised and quantified using Ki-67. We found a transient reduction in immunohistochemical expression of γ actin, 204 kDa MHC isoform and vinculin at 3 and 6 d in the inner media, associated with a transient increase in Ki-67 labelling. The actin content also decreased at 3 and 6 d ( P < 0.05), but there was a postnatal, permanent increase in monomeric actin, first the α then the γ isoform. The relative proportions of the MHC isoforms did not change between birth and adulthood in elastic pulmonary arteries but in muscular arteries the 200 kDa isoform increased between 14 d and adulthood. Pulmonary hypertension prevented both the immunohistochemical changes and the postnatal burst of SMC replication and prevented the transient postnatal reduction in actin content. These findings suggest that rapid remodelling of the actin cytoskeleton is an essential prerequisite of a normal postnatal fall in pulmonary vascular resistance.     

钙敏感受体通过PI3K信号通路介导缺氧诱导的大鼠肺动脉平滑肌细胞增殖

目的:探讨钙敏感受体(CaSR)在缺氧诱导的大鼠肺动脉平滑肌细胞(PASMCs)增殖中的信号转导途径。方法:Ⅱ型胶原酶消化法提取、培养大鼠PASMCs。通过缺氧培养箱内(93%N₂、2%O₂、5%CO₂)培养24h的方法复制细胞缺氧模型。应用Western blotting分析不同处理情况下细胞周期素D1(cyclin D1)及磷酸化的蛋白激酶B(p-Akt)在PASMCs中的表达;采用流式细胞术检测不同处理因素对细胞增殖周期及增殖指数的影响,应用BrdU掺入法分析不同处理因素对细胞DNA合成的影响。结果:缺氧引起PASMCs的cyclin D1及p-Akt表达水平上调,增加BrdU掺入量、S期细胞数量和细胞增殖指数,GdCl₃能够放大缺氧的作用,但上述效应可以被LY294002抑制。结论:CaSR通过PI3K/Akt信号通路参与缺氧诱导的大鼠PASMCs增殖。     

Altered collagen homeostasis in human aortic smooth muscle cells (HAoSMCs) induced by aldosterone

The importance of aldosterone for cardiovascular diseases is well established. Most of the adverse effects seem to originate from its ability to produce vascular injury, including fibrosis. It is currently under debate whether aldosterone per se is able to induce fibrosis or whether it acts as a cofactor under pathological conditions. We tested whether aldosterone per se and in the presence of reactive oxygen stress (H₂O₂) enhances collagen abundance in human aortic smooth muscle cell (HAoSMC) media in primary culture and, if so, by which means. Collagen abundance, as well as epidermal growth factor receptor (EGFR) expression and ERK1/2 phosphorylation, was investigated by ELISA and Western blot. Collagenase activity and H₂O₂ formation were determined by fluorometry and luminometry. Aldosterone alone did not affect collagen abundance but potentiated the stimulatory effect of low concentrations of H₂O₂ (1-10 μmol/l). This effect disappeared when shedding of membrane-bound EGFR ligands was prevented by GM6001. EGFR expression and cellular EGF responsiveness were enhanced by aldosterone. Inhibition of the EGFR kinase (tyrphostin AG1478) prevented the increase of collagen. The increase in collagen abundance was prevented by blockade of the mineralocorticoid receptor (MR) and could be reproduced by MR transfection into Chinese hamster ovary cells. We conclude that aldosterone sensitizes HAoSMC for H₂O₂-induced increase of collagen abundance at least in part by enhanced EGFR expression.     

抑制肌球蛋白轻链激酶活性对内皮素-1诱导的大鼠肺动脉平滑肌细胞增殖及凋亡失衡的影响

目的:观察抑制肌球蛋白轻链激酶(MLCK)对内皮素-1(ET-1)诱导的大鼠肺动脉平滑肌细胞(pulmonary artery smooth muscle cells,PASMCs)增殖与凋亡失衡的影响。方法:细胞分成3组:对照组;内皮素-1组;内皮素-1+肌球蛋白轻链激酶抑制剂组(ET-1+M组)。干预72 h后,免疫印迹法测定细胞内MLCK表达水平;甘油凝胶电泳和免疫印迹法检测肌球蛋白轻链(MLC)的磷酸化水平,MTT比色法及[3H]-TdR掺入法检测PASMCs的增殖情况,流式细胞仪检测PASMCs的细胞周期变化及凋亡率。结果:同对照组比较,ET-1刺激后肺动脉平滑肌细胞MLCK蛋白表达显著增强、MLC磷酸化上调、增殖增多、凋亡率明显降低(均P0.05);加入MLCK抑制剂干预后,MLCK表达明显下降(P0.05)、MLC去磷酸化显著增强、逆转了ET-1对PASMCs增殖及凋亡的影响。结论:抑制MLCK能显著逆转内皮素-1诱导的大鼠肺动脉平滑肌细胞增殖与凋亡的失衡。     

miR-339通过靶向调控IGF2BP1抑制肺动脉平滑肌细胞的增殖

目的:本研究旨在探讨微小RNA-339(miR-339)在肺动脉平滑肌细胞(PASMCs)增殖中的作用并探讨其潜在机制。方法:利用不同浓度的血管紧张素Ⅱ处理PASMCs 48 h,通过转染miR-339模拟物(miR-339mimic)和miR-339抑制物(miR-339 inhibitor)分别使miR-339过表达或低表达,利用CCK-8法和活细胞计数检测细胞的增殖能力;利用RT-qPCR检测miR-339和PCNA mRNA的表达水平;利用Western blot检测蛋白水平;萤光素酶报告试验分析证实miR-339和IGF2BP1之间的相互作用。结果:血管紧张素II浓度依赖性地增加PASMCs的增殖和PCNA的mRNA表达,并降低miR-339的表达(P 0. 05)。miR-339过表达抑制PASMCs增殖和PCNA mRNA表达(P 0. 05),而miR-339表达下调则促进PASMCs的增殖和PCNA的mRNA表达(P 0. 05)。miR-339表达上调可以抑制血管紧张素II处理后的PASMCs的增殖(P 0. 05)。生物信息学分析以及萤光素酶报告试验检测证实胰岛素样生长因子2 mRNA结合蛋白1(IGF2BP1)的3’-UTR为miR-339靶点,进一步用RT-qPCR及Western blot实验发现miR-339负调控PASMCs中IGF2BP1的表达(P 0. 05)。IGF2BP1的过表达减弱了miR-339对PASMCs增殖和PCNA mRNA表达的抑制作用(P 0. 05)。miR-339 mimic转染可以抑制磷酸化p38蛋白的水平(P 0. 05),对p38蛋白的水平没有影响。结论:miR-339对PASMCs的增殖起抑制作用,这种抑制作用可能是部分通过调控IGF2BP1以及p38 MAPK信号通路来实现的。     

Inhibitory effect of rapamycin on proliferation of human umbilical arterial smooth muscle cells

Abstract

Objective: Rapamycin has a protective cardiovascular effect and inhibits proliferation and migration of vascular smooth muscle cells. We investigated the effects of rapamycin on proliferation of cultured human umbilical arterial smooth muscle cells (HUASMCs) by determining interleukin-6 (IL-6) levels.

Materials and methods: Adherent third-generation primary-cultured HUASMCs were used in the study, and MTT assay was used to measure the effects of different rapamycin concentrations on cell proliferation at various time points (3–96?h). RT-PCR was used to measure IL-6 mRNA expression and ELISA was used to measure IL-6 protein expression.

Results: After three passages, HUASMCs displayed >90% confluence. Inhibition of cell proliferation by rapamycin was both time and dose dependent. When the action concentration of rapamycin was 100?ng·mL^–1, the inhibitory effect was strongest after 48?h (30.25?±?2.40)%, and the follow-up study was conducted after 48?h. When the action time of rapamycin was 48?h, the inhibitory effect of 150?ng·mL^–1 at the action concentration was the strongest, and the inhibitory rate was (42.88?±?3.84)%. There was no significant difference between the inhibitory effect and the action concentration of 100?ng·mL^–1 (p>.05). Moreover, low (2?ng·mL^–1), moderate (10?ng·mL^–1), and high (100?ng·mL^–1) rapamycin concentrations down-regulated both IL-6 mRNA and expression factor in a dose-dependent manner.

Discussion and conclusions: Rapamycin inhibits proliferation of HUASMCs in vitro and through down-regulation of IL-6 expression.     

慢性缺氧对大鼠肺动脉平滑肌细胞胞内钙的影响及其机制研究

目的:研究慢性缺氧对大鼠肺动脉平滑肌细胞(PASMCs)胞内钙浓度(［Ca²⁺］_i)的影响及L-型钙通道和胞内钙库的作用,为缺氧性肺动脉高压(HPH)发病机制的进一步研究提供理论依据。 方法:复制大鼠缺氧性肺动脉高压动物模型，利用Fura－2/AM钙离子成像方法测定PASMCs在不同钙离子浓度细胞外液及L-型钙通道阻滞剂nifedipine和IP3R钙通道抑制剂肝素干预前后 ［Ca²⁺］_i变化。 结果:(1)缺氧＋含钙外液组PASMCs ［Ca²⁺］_i 显著高于对照＋含钙外液组（P<0.05）。缺氧＋含钙外液组PASMCs ［Ca²⁺］_i显著高于缺氧＋无钙外液组（P<0.05）。(2)缺氧nifedipine组PASMCs［Ca²⁺］_i在加药前后无显著差异（P>0.05）。（3）缺氧未干预组与缺氧肝素组PASMCs ［Ca²⁺］_i无明显差异（P>0.05）。 结论:慢性缺氧可使PASMCs的［Ca²⁺］_i增加。慢性缺氧引起［Ca²⁺］_i增加可能与细胞外钙内流有关，L-型钙通道和IP3R钙通道在调节［Ca²⁺］_i的过程中可能不独立发挥作用。     

PI-3K在低氧大鼠肺动脉平滑肌细胞增殖中的表达

目的:研究低氧肺动脉平滑肌细胞(PASMC)增殖时磷脂酰肌醇3 激酶(PI-3K)的表达。方法:实验分为无血清培养基(SFM)组和低氧48 h(H48 h)组, 应用免疫组织化学法和流式细胞仪检测低氧PASMC。结果:SFM组和H48 h组PASMC细胞浆内均有PI-3K p110阳性表达, H48 h组(0.1891±0.0301)的表达明显高于SFM组(0.1025±0.0164, P＜0.05);PCNA在SFM组的少数PASMC细胞核内有阳性表达, H48h组(24.58±4.07)%的增殖指数(PI)明显高于SFM组(8.76±1.21)%(P＜0.05);流式细胞仪检测发现PASMC的S+G₂／M期细胞所占细胞总数的百分比在H48 h(27.15±5.43)%显著高于SFM组(10.64±1.52)%(P＜0.05)。结论:低氧可显著上调PI3K的表达, 提示PI-3K可能在低氧PASMC增殖中起重要作用。     

Effect of annexin A2 on hepatopulmonary syndrome rat serum-induced proliferation of pulmonary arterial smooth muscle cells

Hepatopulmonary syndrome (HPS) is characterizes by an arterial oxygenation defect induced by intrapulmonary vasodilation that increase morbidity and mortality. However, the underlying mechanisms on HPS-associated pulmonary vascular remodeling remains undefined. In this study, we found that HPS rat serum, drawn from common bile duct ligation (CBDL) rats, mediated the overexpression of ANXA2 and the proliferation of PASMCs. And small interfering RNA (siRNA) that target rat ANXA2 led to significant downregulation of ANXA2, which resulted in the decreased proliferation of PASMCs. Subsequently, we further examined the role of ANXA2 siRNA in the regulation of pro-proliferative signaling such as that mediated by ERK1/2 and NF-κB, and found the attenuation of HPS-associated activation of the signaling pathway. Thus, the fact highlighted the crucial role of ANXA2 in HPS-associated PASMC proliferation, and suggested a potential therapeutic effect on HPS-associated pulmonary vascular remodeling.     

Mechanisms simultaneously regulate smooth muscle proliferation and differentiation

Vascular smooth muscle cell(VSMC) differentiation and proliferation are two important physiological processes during vascular development.The phenotypic alteration from differentiated to proliferative VSMC contributes to the development of several major cardiovascular diseases including atherosclerosis,hypertension,restenosis after angioplasty or bypass,diabetic vascular complications,and transplantation arteriopathy.Since the VSMC phenotype in these pathological conditions resembles that of developing VSMC during embryonic development,understanding of the molecular mechanisms that control VSMC differentiation will provide fundamental insights into the pathological processes of these cardiovascular diseases.Although VSMC differentiation is usually accompanied by an irreversible cell cycle exit,VSMC proliferation and differentiation occur concurrently during embryonic development.The molecular mechanisms simultaneously regulating these two processes,however,remain largely unknown.Our recent study demonstrates that cell division cycle 7,a key regulator of cell cycle,promotes both VSMC differentiation and proliferation through different mechanisms during the initial phase of VSMC differentiation.Conversely,Krüppel-like factor 4 appears to be a repressor for both VSMC differentiation and proliferation.This review attempts to highlight the novel role of cell division cycle 7 in TGF-β-induced VSMC differentiation and proliferation.The role of Krüppel-like factor 4 in suppressing these two processes will also be discussed.     

Smad通路参与ERK通路诱导血管平滑肌细胞增殖的过程

目的： 探讨Smad通路是否参与细胞外信号调节激酶(ERK)通路诱导血管平滑肌细胞（VSMCs）增殖的过程及其可能机制。方法：将人脐动脉平滑肌细胞（hUASMCs）分为对照组、血小板源性生长因子（PDGF）组、ERK阻断剂组和PDGF+ERK阻断剂组。用MTT法测hUASMCs的增殖活性(A值)，用免疫组化法测hUASMCs内细胞核增殖抗原（PCNA）、磷酸化ERK和磷酸化Smad蛋白的表达，用RT-PCR法测hUASMCs内Smad2/3 mRNA的表达。结果：PDGF组hUASMCs的增殖活性(A值)及hUASMCs内的PCNA、磷酸化ERK和磷酸化Smad2/3蛋白的表达都明显高于其它各组(P<0.01)；各组hUASMCs内Smad2/3 mRNA的表达没有差异。结论： Smad通路可在蛋白水平参与ERK通路诱导VSMCs的增殖过程。     

缓激肽对TGF-β1诱导的猪肺动脉平滑肌细胞增殖的影响

 目的：研究缓激肽（BK）对转化生长因子 β1（TGF-β1）诱导的肺动脉平滑肌细胞（PASMCs）增殖的影响及其可能机制。方法：原代培养猪PASMCs,采用CCK-8法测定BK对TGF-β1诱导的PASMCs增殖能力的影响,同时应用Western blotting检测PASMCs PI3K、p-Akt和p-ERK1/2表达的变化。结果：TGF-β1呈剂量依赖性促进PASMCs增殖（P<005）,BK显著抑制了TGF-β1诱导的PASMCs增殖（P<005）,而BK 2型受体（B2R）抑制剂HOE-140可以显著抑制BK的效应（P<005）;Western blotting结果显示,BK抑制TGF-β1诱导的PASMCs增殖主要是通过阻断PI3K/Akt和ERK1/2信号通路活化而实现。结论：BK显著抑制TGF-β1诱导的PASMCs增殖,此作用可能与其抑制PI3K/Akt和ERK1/2信号通路活化有关。     

内皮细胞条件培养液对平滑肌细胞合成胶原的影响

本实验采用胶原酶消化法分离、培养兔主动脉内皮细胞(EC)及平滑肌细胞(SMC),以[~3H]-脯氨酸掺入SMC合成的[~3H]-羟脯氨酸中的量作为测定胶原的指标,观察了兔主动脉内皮细胞条件培养液(EC-CM)对动脉SMC合成胶原的影响,结果发现融合的EC-CM能促进SMC的胶原合成,但SMC数无明显变化;1:2稀释的EC-CM促进SMC合成胶原的作用最大。可见EC通过促进SMC的胶原合成而参与了动脉粥样硬化过程。