兔后肢缺血诱导侧支血管生长过程中巨噬细胞浸润的变化

目的检测兔侧支血管生长过程中各时期巨噬细胞的浸润情况;方法单侧结扎兔后肢股动脉,随后将股动脉结扎的远侧端连到相邻的静脉上造成动静脉短路,另侧为对照组,分别存活2d,1周,2周,4周后处死,用特异性的巨噬细胞抗体(RAM11)免疫荧光组织化学结合共聚焦技术检测侧支血管壁内巨噬细胞的数目及其分布;结果在正常血管,其外膜有少量巨噬细胞的存在,股动脉结扎后2d,侧支血管外膜巨噬细胞的数目增加,并黏附至内皮细胞,结扎1周后,侧支血管外膜巨噬细胞的数目显著增加,中膜有巨噬细胞的浸润,结扎2周后,侧支血管外膜巨噬细胞的数目减少,但仍高于正常血管,结扎4周后,侧支血管巨噬细胞的数目明显减少,跟正常血管情况类似,统计学分析结果表明,在结扎后2d、一周、二周和四周不同的时间,巨噬细胞在侧支血管的分布差异具有显著性;结论侧支血管发育过程中巨噬细胞的浸润和侧支血管的形成密切相关,提示巨噬细胞参与了侧支血管的生长发育。     

血管内皮生长因子及其受体2与哮喘模型大鼠气道平滑肌细胞增殖关系的研究

目的探讨血管内皮生长因子(VEGF)及其受体2(Flk-1)在哮喘大鼠气道平滑肌细胞(ASMC)中表达变化及其对ASMC增殖的影响。方法 SD大鼠18只,随机分为对照组,哮喘模型组和地塞米松干预组各6只,并培养各组气道平滑肌细胞。用免疫组织化学技术检测ASMC增殖细胞核抗原(PCNA)的表达;用RT-PCR及Western blot方法分别检测VEGF和Flk-1mRNA及蛋白质在不同组大鼠ASMC的表达程度。结果(1)哮喘模型组ASMC PCNA表达较对照组和干预组显著增加(P0.05)。(2)哮喘模型组ASMC VEGF164,VEGF188mRNA和VEGF205mRNA的表达较对照组和干预组显著增加(P0.05或P0.01)。(3)哮喘模型组ASMC VEGF及Flk-1蛋白质在大鼠ASMC中的表达较对照组和干预组显著增加(P0.05)。直线相关性分析显示,大鼠ASMC PCNA表达与大鼠ASMC中VEGF205,188,164及Flk-1mRNA表达水平呈正相关(r分别为0.79,0.86,0.83,0.68;P0.05);大鼠ASMC PCNA表达与大鼠ASMC中VEGF及Flk-1蛋白质表达水平也呈正相关(r分别为0.80,0.77;P0.05)。结果 哮喘模型大鼠ASMC中VEGF及其受体Flk-1表达上调,并与气道平滑肌细胞增殖有密切关系。该结果提示VEGF及其受体2可能参与了哮喘气道重建中气道平滑肌细胞增殖的过程。     

VEGF与其受体2在哮喘大鼠气道中表达变化及其对气道平滑肌细胞增殖的影响

目的探讨血管内皮生长因子(VEGF)及其受体2(Flk-1)在哮喘大鼠气道中表达变化及其对气道平滑肌细胞增殖的影响.方法 SD大鼠18只,随机分为对照组,哮喘模型组和地塞米松干预组各6只.以腹腔注射1%卵蛋白致敏和2%卵蛋白雾化吸入激发复制哮喘模型,干预组在每次激发前给予地塞米松干预.用免疫组织化学技术检测气道平滑肌α-actin以及VEGF和Flk-1蛋白质在不同组大鼠肺组织的表达程度;用RT-PCR方法检测VEGF和Flk-1mRNA在不同组大鼠肺组织的表达程度;采用HMIAS-2000型高清晰度彩色医学图文分析系统进行图像分析.结果 (1)哮喘模型组气道壁平滑肌厚度较对照组和干预组显著增加(P<0.05).(2)哮喘模型组VEGF及Flk-1蛋白质在大鼠肺组织中的表达较对照组和干预组显著增加(P<0.05).(3)哮喘模型组VEGF144,VEGF188 mRNA和VEGF205 mRNA在大鼠肺组织中的表达较对照组和干预组显著增加(P<0.05或P<0.01).哮喘模型组Flk-1mRNA在大鼠肺组织中的表达较对照组和干预组显著增加(P<0.05).直线相关性分析显示,气道壁平滑肌厚度与大鼠肺组织中VEGF205,188,144及Flk-1mRNA表达水平呈正相关(r分别为0.739,0.747,0.744,0.682;P<0.05);气道壁平滑肌厚度与大鼠肺组织中VEGF及Flk-1蛋白质表达水平也呈正相关(r分别为0.693,0.672;P<0.05).结论哮喘模型大鼠肺组织中VEGF及其受体Flk-1表达上调,并与气道平滑肌增殖有密切关系.该结果提示VEGF及其受体2可能参与了哮喘气道重建中气道平滑肌增殖的过程.     

乳腺癌及癌前病变血管生成相关分子的表达及意义

目的探讨血管生成异常与乳腺癌发生发展的关系。方法采用免疫组化方法检测30例正常乳腺,30例普通性增生,30例非典型增生（AH）,20例导管内癌,50例浸润性导管癌组织中微血管密度（MVD）、VEGF及受体Flk-1/KDR的表达变化。结果各组CD34、VEGF及Flk-1/KDR的表达程度不同,浸润性导管癌组最高。随病程演进,MVD增加（P〈0.05）,VEGF及其受体Flk-1/KDR在血管内皮细胞表达渐进增高（P〈0.05）,但在病程初期各主要指标改变不明显,显著变化始于AH阶段。MVD在AH与导管内癌组间差异不显著（P〉0.05）,VEGF及Flk-1/KDR的表达在AH与导管内癌组间有显著差异（P〈0.05）。结论血管生成在乳腺癌发生发展过程中起着重要作用,血管生成异常可能是乳腺癌发生过程中的早期事件。VEGF及其受体Flk-1/KDR的表达异常可能是乳腺普通性增生-AH-乳腺癌这一癌性转化过程中血管生成异常的主要始动因素,VEGF及其受体Flk-1/KDR可能成为乳腺癌早期诊断及治疗的分子靶标。     

一氧化氮对小鼠胚胎围植入期子宫VEGF及其受体表达的调节

为研究NO在胚胎植入中的作用机理 ,本文采用子宫角注射、原位杂交及Westernblot方法研究了一氧化氮 (NO)在小鼠胚胎植入过程中对血管内皮生长因子 (VEGF)及其受体表达的调节。受试小鼠于妊娠第三天 (D3 )在一侧子宫角内注射一氧化氮合酶 (NOS)抑制剂N 硝基 L 精氨酸甲酯 (L NAME)或者L NAME与NO的供体硝普钠 (SNP)合用 ,另一侧子宫角为对照侧 ;收集并分别检测了D5,D6和D7天小鼠子宫中VEGF及其受体mRNA和蛋白的表达情况。结果显示 :与对照侧相比 ,L NAME处理后小鼠胚胎围植入期子宫中VEGF及其受体mRNA的表达有不同程度的下降 ;对VEGF及其受体蛋白表达水平检测表明 ,抑制的NO产生也使VEGF及其受体蛋白在小鼠围植入期子宫中的表达有不同程度的降低。当NOS抑制剂和NO的供体SNP同时注射小鼠时 ,VEGF及其受体mRNA和蛋白表达都恢复到正常水平。以上结果表明 ,在小鼠胚胎植入中NO可通过调节VEGF及其受体的表达参与血管新生 ,从而对胚胎植入起到调节作用     

骨髓基质干细胞移植对扩张型心肌病心衰大鼠心功能改善作用机制的研究

通过对心肌胶原纤维、微血管生成、血管内皮生长因子(VEGF)及其受体表达的研究,探讨骨髓基质干细胞(BMSSCs)心肌内移植对扩张型心肌病心衰大鼠心功能的保护机制．应用阿霉素注射法建立扩张型心肌病心衰大鼠模型,成功建模后移植4', 6-二乙酰基-2-苯基吲哚(DAPI)标记的BMSSCs．分别于术后1、2、3、4周进行血流动力学检测,利用免疫组化、RT-PCR技术分析心肌胶原纤维、血管内皮生长因子(VEGF)及其受体Flt-1、Flk-1表达的改变,以及微血管密度．结果显示,移植细胞于术后4周通过免疫荧光可检测到存活．于术后2周开始,移植组心功能较对照组改善,表现为移植组收缩压(LVSP)、左心室内压最大上升或下降速率(?dp/dt)较对照组显著升高,舒张压(LVDP)显著下降,P < 0.05．移植组心肌胶原纤维沉积减少,光密度值比较P < 0.05．移植组VEGF、Flt-1、Flk-1表达较同期对照组增加,并张且与其受体达峰时间不同步．4周时移植组微血管密度明显高于对照组．上述结果表明,BMSSCs移植后可通过上调受体内VEGF、Flt-1、Flk-1的表达,促进血管新生,减少胶原纤维沉积,从而改善受体心脏的功能．     

人脐静脉血管平滑肌促内皮细胞组织因子表达的体外实验研究

目的研究血管平滑肌细胞对血管内皮细胞组织因子表达的影响并探讨其临床意义.方法用贴块法培养人脐静脉平滑肌细胞;酶消化法培养人脐静脉内皮细胞;用培养平滑肌细胞条件培养液(SMC-CM)刺激培养的内皮细胞,一步凝固法检测内皮细胞组织因子的活性;Northern blot检测内皮细胞组织因子的mRNA表达;并用酶联免疫吸附试验检测SMC-CM中IL-1α、IL-1β、TNF-α和VEGF的含量.结果 SMC-CM使内皮细胞组织因子活性呈剂量依赖性增强,作用6h增至最高,最高增强约38倍;SMC-CM使内皮细胞组织因子mRNA表达显著增强;SMC-CM中的组织因子诱导剂不耐热,且并非IL-1α、IL-1β、TNF-α和VEGF等已知的组织因子诱导剂.结论血管平滑肌细胞能促进血管内皮细胞组织因子的表达,提示体内增生的平滑肌细胞,如动脉再狭窄新内膜中的平滑肌细胞可能诱导局部血管内皮细胞活化及表达组织因子,在局部血栓形成中起一定作用.     

白藜芦醇促进老年大鼠缺血后肢侧支血管生长

目的 本研究旨在探讨白藜芦醇对老年大鼠缺血后肢侧支血管生长的影响。方法 采用老年大鼠股动脉结扎建立侧支血管生长模型,10 mg/kg白藜芦醇处理,免疫荧光染色和HE染色观察大鼠后肢侧支血管生长情况。结果 HE染色显示,股动脉结扎后给予白藜芦醇处理使侧支血管管壁增厚,管腔增大;免疫荧光染色显示,股动脉结扎后给予白藜芦醇处理使侧支血管管壁增殖细胞（Ki-67阳性细胞）增多,eNOS表达增强。结论 白藜芦醇可促进老年大鼠缺血后肢侧支血管的生长。     

DR和CT对大鼠股动脉结扎诱导的侧支血管显像能力的对比研究

目的:探讨数字化X线摄影(digital radiography,DR)和电子计算机断层扫描成像(Computed Tomography,CT)对大鼠股动脉结扎诱导的侧支血管显像能力的对比.方法:28只健康SD大鼠,右侧行股动脉结扎,存活1W,采用明胶-四氧化三铅混合物行血管造影观察大鼠后肢侧支血管形成情况并分别采用DR及CT进行摄片,观察DR及CT对侧支血管的显像能力.结果:DR及CT均显示在股动脉结扎处血管连续性中断,并出现不同数量的侧支血管;DR对新生侧支血管的显影分辨率和清晰度明显高于CT,且远端股动脉显影较CT清晰,CT横断面成像具有放射状伪影.结论:经DR拍摄的侧支血管的显像能力较CT清晰,利用DR可以直观清晰的将其显像.     

血管内皮生长因子基因对兔髂动脉内膜损伤的组织形态变化过程的影响

探讨血管内皮细胞的特异丝裂原－血管内皮生长因子（VEGF）基因阻止血管内膜损伤后形成再狭窄的组织变化过程。建立球囊拉伤血管内膜的兔髂动脉模型,将携带VEGF目的基因的真核表达载体pcDNA3/VEGF经多聚赖氨酸处理的PTCA球囊导管导入拉伤的血管内膜。VEGF基因组拉伤2周时血管内壁有VEGF mRNA和蛋白的高表达。血管内膜内皮化较快。2周时即有许多血管内皮细胞呈岛状分布。4周时内膜基本恢复光滑。内膜平滑肌细胞增生明显减少,而对照组2周时血管内膜粗糙,基底膜暴露,拉伤后4周仍无内皮细胞再生,最后形成虫蚀样改变。血管中膜平滑肌细胞穿过内弹性膜进入内膜并大量增生,内膜增厚。VEGF基因定位导入血管内壁后。VEGF mRNA和蛋白高表达且发挥其生物学效应,内皮细胞岛状增生,加快内膜内皮化,减轻内膜增厚。     

Involvement of neuronal NO synthase in collateral artery growth

To evaluate the role of neuronal nitric oxides synthase (nNOS) in collateral artery growth (arteriogenesis), we analyzed the expression pattern of nNOS at distinct time points on RNA and protein levels in a rabbit and a murine model of peripheral arteriogenesis. In the rabbit model, Northern blot analyses revealed a significant upregulation of nNOS at 6 h (1.6-fold), 12 h (2.2-fold) and 24 h (2.0-fold) after induction of arteriogenesis via femoral artery ligation, when compared to the sham operated side. In mice, an upregulation of nNOS was also detected using Northern blot (at 6 h, 12 h) and qRT-PCR (12 h: 2.4-fold). On the protein level, nNOS was found to be upregulated 24 h after femoral artery ligation. Immunohistochemical staining showed that nNOS was localized in endothelial and smooth muscle cells of collateral arteries, as well as in skeletal muscle and nerves. In summary, our data provide evidence that nNOS is not constitutively expressed, but is induced during arteriogenesis, playing a role in supplying reactive oxygen species such as H2O2 and low levels of NO.     

Collateral vessel growth induced by femoral artery ligature is impaired by denervation

Innervation plays an important role in development and remodeling of blood vessels. However, very little is known whether innervation is involved in arteriogenesis. In the present study, we tested the hypothesis that innervation may contribute to the process of arteriogenesis induced by ligature of femoral artery in rat/rabbit hind limb with or without denervation. We found that: (1) angiography showed more collateral vessels in the ligature side than that in ligature plus denervation side; (2) collateral vessels in denervation side was characterized by an inward remodeling; (3) in both collateral vessels (CVs) from only femoral ligature side as well as the ligature plus denervation side, ICAM-1 and VCAM-1 expression was up-regulated but increased VCAM-1 was more evident in the adventitia of collateral vessels of only femoral ligature side; (4) 7 days after surgery, in CVs from the femoral ligature side only, numerous macrophages (RAM11 positive cells) and high cell proliferation ratio (ki67 positive cells) were detected, but they were less in the denervation side. In conclusion, our data demonstrate for the first time that neural regulation is one of the factors that contributes to collateral vessel growth in rat/rabbit hind limb ischemic model by showing collateral vessel growth induced by femoral artery ligature is impaired by denervation.     

VEGF receptor antagonism blocks arteriogenesis, but only partially inhibits angiogenesis, in skeletal muscle of exercise-trained rats

Both collateral vessel enlargement (arteriogenesis) and capillary growth (angiogenesis) in skeletal muscle occur in response to exercise training. Vascular endothelial growth factor (VEGF) is implicated in both processes. Thus we examined the effect of a VEGF receptor (VEGF-R) inhibitor (ZD4190, AstraZeneca) on collateral-dependent blood flow in vivo and collateral artery size ex vivo (indicators of arteriogenesis) and capillary contacts per fiber (CCF; an index of angiogenesis) in skeletal muscle of both sedentary and exercise-trained rats 14 days after bilateral occlusion of the femoral arteries. Total daily treadmill run time increased appreciably from approximately 70 to approximately 100 min (at 15-20 m/min, twice per day) and produced a large (approximately 75%, P < 0.01) increase in calf muscle blood flow and a greater size of the collateral artery (wall cross-sectional area). ZD4190, which previously has been shown to inhibit the activity of VEGF-R2 and -R1 tyrosine kinase in vitro (IC50 = 30 and 700 nM, respectively), completely blocked the increase in collateral-dependent blood flow and inhibited collateral vessel enlargement. Thus exercise-stimulated collateral arteriogenesis appears to be completely dependent on VEGF-R signaling. Interestingly, enhanced mRNA expression of the VEGF family ligand placental growth factor (2- to 3.5-fold), VEGF-R1 (approximately 2-fold), and endothelial nitric oxide synthase (2- to 3.5-fold) in an isolated collateral artery implicates these factors as important in arteriogenesis. Training of ischemic muscle also induced angiogenesis, as shown by an increase (approximately 25%, P < 0.01) in CCF in white gastrocnemius muscle. VEGF-R inhibition only partially blocked (P < 0.01) but did not eliminate the increase (P < 0.01) in capillarity. Our findings indicate that VEGF-R tyrosine kinase activity is essential for collateral arteriogenesis and important for the angiogenesis induced in ischemic muscle by exercise training; however, other angiogenic stimuli are also important for angiogenesis in flow-limited active muscle.     

Activation of the integrins α5β1 and αvβ3 and focal adhesion kinase (FAK) during arteriogenesis

Migration and proliferation of smooth muscle cells (SMC) are important events during arteriogenesis, but the underlying mechanism is still only partially understood. The present study investigates the expression of integrins alpha 5 beta 1 and v beta 3 as well as focal adhesion kinase (FAK) and phosphorylated FAK (pY397), key mediators for cell migration and proliferation, in collateral vessels (CV) in rabbit hind limbs induced by femoral ligation or an arteriovenous (AV) shunt created between the distal femoral artery stump and the accompanying femoral vein by confocal immunofluorescence. In addition, the effect of the extracellular matrix components fibronectin (FN), laminin (LN), and Matrigel on expression of these focal adhesion molecules proliferation was studied in cultured SMCs. We found that: (1) in normal vessels (NV), both integrins alpha 5 beta 1 and alpha v beta 3 were mainly expressed in endothelial cells, very weak in smooth muscle cells (SMC); (2) in CVs, both alpha 5 beta 1 and alpha v beta 3 were significantly upregulated (P < 0.05); this was more evident in the shunt-side CVs, 1.5 and 1.3 times higher than that in the ligation side, respectively; (3) FAK and FAK(py397) were expressed in NVs and CVs in a similar profile as was alpha 5 beta 1 and alpha v beta 3; (4) in vitro SMCs cultured on fibronectin (overexpressed in collaterals) expressed higher levels of FAK, FAK (pY397), alpha 5 beta 1, and alpha v beta 3 than on laminin, whereas SMCs growing inside Matrigel expressed little of these proteins and showed no proliferation. In conclusion, our data demonstrate for the first time that the integrin-FAK signaling axis is activated in collateral vessels and that altered expression of FN and LN may play a crucial role in mediating the integrin-FAK signaling pathway activation. These findings explain a large part of the positive remodeling that collateral vessels undergo under the influence of high fluid shear stress.     

Vascular endothelial growth factor (VEGF) stimulates monocyte migration through endothelial monolayers via increased integrin expression

Monocytes play an important role in collateral vessel formation (arteriogenesis) by attaching to activated endothelium and by invading the walls of innate collateral vessels where they produce growth factors. Previous studies have demonstrated that this process can be promoted by several chemokines and growth factors. In this study we examined the interaction between monocytes and endothelium under stimulation of the angiogenic agent vascular endothelial growth factor (VEGF). We report here the novel finding that VEGF stimulates the expression of the alphaL-, alphaM- and beta2-integrin monomers. In functional assays and by using neutralizing antibodies it was shown that VEGF stimulates adhesion of monocytes to human umbilical vein endothelial cells (HUVEC), and increased transmigration through endothelial monolayers is dependent on interaction of monocyte beta2-integrins with its endothelial counter ligand ICAM-1. Based on these in vitro data we hypothesize that the positive effect of VEGF on arteriogenesis may involve monocyte activation.     

Enhanced arteriogenesis in mice overexpressing erythropoietin

After permanent occlusion of the femoral artery, the survival of ischemic limb tissue depends on collateral artery growth (arteriogenesis). In previous work, we have shown that shear stress triggers arteriogenesis. To test whether increased shear stress results in enhanced arteriogenesis, we compared arteriogenesis in transgenic mice overexpressing erythropoietin (EPO), which possessed increased blood viscosity through the higher hematocrit (thereby providing increased shear stress), with wild-type mice. The right femoral artery was occluded proximal to the origin of the arteria poplitea. Distal blood flow was assessed by laser Doppler imaging, and the growth and remodeling of collateral arteries was examined by light and electron microscopy and morphometry. After occlusion of the femoral artery, EPO mice demonstrated enhanced arteriogenesis: their collateral arteries developed a 1.7-fold diameter and a 2-fold wall thickness compared with wild-type. However, the blood flow recovery in EPO mice was markedly retarded. Structural remodeling and growth of collateral arteries was markedly enhanced in EPO mice, presumably as a result of increased blood viscosity and shear stress.     

The proteoglycan osteoglycin/mimecan is correlated with arteriogenesis

Arteriogenesis or collateral growth is able to compensate for the stenosis of major arteries. Using differential display RT-PCR on growing and quiescent collateral arteries in a rabbit femoral artery ligation model, we cloned the rabbit full-length cDNA of osteoglycin/mimecan. Osteoglycin was present in the adventitia of collateral arteries as a glycosylated protein without keratan sulfate side chains, mainly produced by smooth muscle cells (SMCs) and perivascular fibroblasts. Northern blot, Western blot, and immunohistochemistry confirmed a collateral artery-specific downregulation of osteoglycin from 6 h to 3 weeks after the onset of arteriogenesis. Treatment of primary SMCs with the arteriogenic protein fibroblast growth factor-2 (FGF-2) resulted in a similar reduction of osteoglycin expression as observed in vivo. Application of the FGF-2 inhibitor polyanethole sulfonic acid (PAS) blocked the downregulation of osteoglycin and interfered with arteriogenesis. From our study we conclude that downregulation of osteoglycin is a fundamental requirement for proper arteriogenesis.     

Expression of endothelial nitric oxide synthase in the vascular wall during arteriogenesis

Nitric oxide (NO) has been demonstrated to play an important role in angiogenesis, and also to be involved in collateral vessel growth. The expression of endothelial NO synthase (eNOS) is moderated partly by blood flow-induced mechanical factors, i.e., shear stress. The purpose of this study was to evaluate how the expression of eNOS correlates with the development of collateral vessels in dog heart, induced by chronic occlusion of the left circumflex artery. Immunoconfocal microscopy using an antibody against eNOS was used to detect expression of eNOS in different stages of arteriogenesis. Collateral vessels were classified into normal, growing and mature vessels by using the cytoskeleton marker desmin. Expression of the growth factors bFGF and metallproteinase-2 (MMP-2) was also examined. The data show that in normal arteriolar vessels, expression of eNOS is very low, but in growing collateral vessel there is a 6.2-fold increase, which, however, returned to normal levels in mature collateral vessels. The expression of eNOS was localized only in endothelium, either in normal or growing vessels. bFGF was very weakly stained in normal vessels, but highly expressed in growing collateral vessels. MMP-2 was strongly stained in neointima, but very weak in endothelium. In addition, we also examined expression of iNOS because iNOS may be induced in vessel injury or in disease states, but it was not detected in either normal or growing collateral vessels. Our findings indicate that the expression pattern of eNOS is closely associated with the development of collateral vessels, suggesting that eNOS plays an important role in arteriogenesis.     

Remodeling of the adventitia during coronary arteriogenesis

We studied the role of the adventitia in adaptive arteriogenesis during the phase of active growth of coronary collateral vessels (CV) induced by chronic occlusion of the left circumflex coronary artery in canine hearts. We used electron microscopy and immunoconfocal (IF) labeling for bFGF, matrix metalloproteinase (MMP)-2, MMP-9, tissue-type plasminogen activator (tPA), its inhibitor (PAI-1), fibronectin (FN), and Ki-67. Proliferation of smooth muscle cells and adventitial fibroblasts was evident. Quantitative IF showed that adventitial MMP-2, MMP-9, and FN were 9.2-, 7.5-, and 8.6-fold, bFGF was 5.1-fold, and PAI-1 was 3.4-fold higher in CV than in normal vessels (NV). The number of fibroblasts was 5-fold elevated in CV, but the elastic fiber content was 25-fold greater in NV than in CV. Perivascular myocyte damage and induction of endothelial nitric oxide synthase in peri-CV capillaries indicate expansion of CV. It was concluded that adventitial activation is associated with the development of CV through cell proliferation, production of growth factors, and induction of extracellular proteolysis thereby contributing to remodeling during adaptive arteriogenesis.     

The ankyrin repeat containing SOCS box protein 5: a novel protein associated with arteriogenesis

Arteriogenesis, the growth of pre-existing collateral arteries, can be induced in rabbit by occlusion of the femoral artery. In order to identify and characterize genes differentially expressed during the early phase of arteriogenesis, cDNA of collateral arteries 24h after femoral ligation or sham operation was subjected to suppression subtractive hybridization. We identified the ankyrin repeat containing SOCS box protein 5 (asb5) and cloned the rabbit full-length cDNA. Asb5 was demonstrated to be a single-copy gene. We localized the asb5 protein in vivo in endothelial and smooth muscle cells of collateral arteries as well as in satellite cells. Asb5 was significantly upregulated in growing collateral arteries on mRNA and protein level. The infusion of doxorubicin in rabbit led to a significant decrease of the asb5 mRNA. In summary, our data show that asb5 is a novel protein implicated in the initiation of arteriogenesis.