血小板源生长因子及其受体与动脉粥样硬化

血小板源生长因子是成纤维细胞、平滑肌细胞及其他间充质来源细胞的强有丝分裂原和化学驱动剂。近年来的研究表明,在动脉粥样斑块发展过程中,血小板源生长因子及血小板源生长因子受体的作用可能尤其重要。文章对血小板源生长因子及其受体的结构、特点、作用和与动脉粥样硬化的病理关系作了简要归纳,以期为更好理解动脉粥样硬化的过程和探索如何防止其发生提供参考。     

动脉壁正常区与脂斑区血小板源性生长因子及其受体基因表达的比较

应用Ｎｏｒｔｈｅｒｎ印迹分析技术测定了正常人主动脉平滑肌细胞血小板源性生长因子及其受体ｍＲＮＡ的表达，以探其与动脉样硬化发生的关系，结果显示，正常动脉壁及有脂纹脂斑动脉的正常区ＰＤＧＦ链ｍＲＮＡ仅有微量表达，未检出ＰＤＧＦ受体ｍＲＮＡ的表达；而脂纹脂斑区的ＰＤＧＦＡ链ｍＲＮＡ及ＰＤＧＦβ－受体ｍＲＮＡ表达则显著增高，提示动脉壁ＰＤＧＦＡ链及受体ｍＲＮＡ表达增高与Ａｓ的发生有关。     

血小板源性生长因子B及其受体在豚鼠哮喘模型气道中的表达

血小板源性生长因子Ｂ及其受体在豚鼠哮喘模型气道中的表达戚好文吕坤聚李焕章李玉松王文勇血小板源性生长因子Ｂ（ＰＤＧＦ－Ｂ）是一种由ｃ－ｓｉｓ原癌基因编码的多肽类生长因子，参与多种疾病的发病过程，但其是否参与哮喘发病目前尚未完全阐明。本研究应用免疫组织化...     

血小板源性生长因子受体表达和活性的调控机制

PDGF-A、PDGF-B及相应受体于20多年前已经分离成功。随着PDGF-C和PDGF-D等新家族成员的不断发现,PDGF系统越来越复杂。与PDGF在细胞生长和生存中的重要作用相一致的是,PDGF受体的表达和活性受到正反馈及负反馈机制的严密调控。调控机制下调可能导致慢性炎症反应和肿瘤等严重疾病的发生。正确认识PDGF及其受体有助于疗效更佳的药物出现。     

血小板源性生长因子及受体与心肌纤维化相关性研究

心肌纤维化(myocardial fibrosis, MF)是心肌组织中胶原合成和降解代谢失衡的结果,以细胞外基质在心肌中过度沉积为特点。心肌纤维化发生机制复杂,肾素-血管紧张素-醛固酮系统、内皮素、缓激肽及细胞因子等均参与其调控过程。血小板源性生长因子作为细胞因子之一与其受体形成通路,诱导胶原的合成与增殖,与心肌纤维化的发生发展密切相关。     

血小板衍生生长因子及其受体与缺血性脑血管病

血小板衍生生长因子(platelet-derived growth factor,PDGF)是一种具有广泛生物学作用的多肽,它是体内较强的促有丝分裂剂和化学诱导剂,与机体组织的生长、发育以及各种损伤后修复有密切的关系.现代医学发现,缺血性脑血管病的发生和发展过程中需要生长因子(如PDGF)的参与.我们着重综述近年来对PDGF及受体功能的研究进展,以及如何在缺血性脑血管病中发挥功能.     

血小板源性生长因子影响血管弹性蛋白酶表达

探讨球囊损伤后血管平滑肌细胞丝氨酸弹性蛋白酶表达增加的机理。用球囊导管损伤Wistar系雄性大鼠主动脉或颈总动脉。以血小板源性生长因子A和大鼠胰腺丝氨酸弹性蛋白酶的地高辛标记RNA探针进行原位杂交，并用抗5-溴脱氧尿嘧啶抗体进行双重染色。用抗血小板源性生长因子从、抗血小板源性生长因子BB、抗胰腺弹性蛋白酶、抗人增殖细胞核抗原等抗体进行免疫染色或免疫双重染色。电镜观察细胞的超微结构。结果发现：①在球囊损伤后O．5～4h，血小板源性生长因子mRNA表达细胞多于弹性蛋白酶mRNA表达细胞；②增殖细胞和迁移细胞既有血小板源性生长因子mRNA和其蛋白表达，又有弹性蛋白酶mRNA和其蛋白表达；③迁移细胞多为增殖细胞核抗原染色阳性．细胞内可见到核分裂像。提示血小板源性生长因子可能是刺激中膜平滑肌细胞增殖、迁移并使其弹性蛋白酶增加的影响因子之一。     

雄激素对老龄大鼠血管平滑肌组织雄激素受体及血小板源性生长因子受体基因表达的影响

2001年10月至2003年2月，我们通过本试验探讨不同剂量的庚酸睾酮(TE)对衰老雄性大鼠血管平滑肌组织中雄激素受体(AR)及血小板源性生长因子受体β(PDGFR-β)基因表达的影响。     

动脉壁正常区与脂斑区血小板源性生长因子及其受体基因表达的比较

应用Ｎｏｒｔｈｅｒｎ印迹分析技术测定了正常人主动脉平滑肌细胞血小板源性生长因子（ｐｌａｔｅｌｅｔｄｅｒｉｖｅｄｇｒｏｗｔｈｆａｃｔｏｒ，ＰＤＧＦ）及其受体ｍＲＮＡ的表达，以探讨其与动脉粥样硬化（ａｔｈｅｒｏｓｃｌｅｒｏｓｉｓ，Ａｓ）发生的关系。结果显示，正常动脉壁及有脂纹脂斑动脉的正常区ＰＤＧＦ链ｍＲＮＡ仅有微量表达，未检出ＰＤＧＦ受体ｍＲＮＡ的表达；而脂纹脂斑区的ＰＤＧＦＡ链ｍＲＮＡ及ＰＤＧＦβ－受体ｍＲＮＡ表达则显著增高。提示动脉壁ＰＤＧＦＡ链及ＰＤＧＦ受体ｍＲＮＡ表达增高与Ａｓ的发生有关。     

亚砷酸钠抑制血小板源性生长因子受体β介导的细胞迁移及其机制

目的研究亚砷酸钠(NaAsO2)对血小板源性生长因子受体β(PDGFRβ)介导细胞迁移的影响及其作用机制。方法用脂质体介导的细胞转染技术将人PDGFRβ表达载体转染体外培养的不表达PDGFRβ的PAE细胞,G418抗性筛选建立稳定转染的细胞株,采用RT-PCR检测PDGFRβ的表达;用细胞损伤修复实验观察细胞损伤24 h完全修复所需的PDGFBB最低浓度;划痕实验观察加入不同浓度NaAsO224 h后,细胞迁移的抑制率;RT-PCR分析不同浓度NaAsO2组中MMP3 mRNA表达水平。结果 RT-PCR检测转染组细胞表达PDGFRβ;细胞损伤修复实验检测细胞损伤24 h完全修复所需的血小板源性生长因子BB(PDGFBB)最低浓度为10μg/L;NaAsO2明显抑制了PDGFRβ介导的细胞迁移,呈典型的剂量效应关系;同时显著下调MMP-3 mRNA表达水平。结论下调MMP3基因表达在NaAsO2抑制PDGFRβ介导的细胞迁移中起重要作用。     

Rat Leydig cells bind platelet-derived growth factor through specific receptors and produce platelet-derived growth factor-like molecules.

The platelet-derived growth factor (PDGF) is a major mitogen for cells of mesenchymal origin. Because Leydig cells arise from mesenchymal precursors, we tested the hypothesis that these cells might be a target for PDGF. We also investigated a possible production of a PDGF-like substance by Leydig cells in culture and the distribution of PDGF-like material in the rat testis using immunohistochemistry. PDGF was found to bind specifically to high affinity receptors on the surface of purified adult rat Leydig cells. Conditioned medium from cultured Leydig cells competed with 125I-labeled PDGF for binding to the Leydig cells. The secretion of PDGF receptor-competing activity was stimulated in a dose-dependent manner by the trophic hormone hCG. Immunohistochemical studies revealed specific staining for PDGF in the Leydig cells of adult rat testis. Taken together these observations suggest that PDGF may play a role in the local control mechanisms of testicular function.     

Two platelet-derived growth factor receptors in vascular smooth muscle cells.

Distinct genes encode alpha and beta PDGF receptors which differ in their abilities to be triggered by three dimeric forms of the PDGF molecules. By use of a strategy involving introduction of expression vectors for alpha and beta PDGF receptor cDNA into the cells originally lacking these receptors, we demonstrated that each receptor was able to couple independently with mitogenic signal transduction pathways inherently present in these cells. Moreover, both receptors were capable of inducing a readily detectable chemotactic response. The vascular smooth muscle cells which express both types of PDGF receptors are mitogenic and chemotactic for PDGFs. Moreover, the alpha receptor is the preferred receptor for platelet PDGF-AB as well as the PDGF-AA isoform which is ubiquitously produced in many cells forming atherosclerotic plaques including macrophages, endothelial cells and even arterial smooth muscle cells. Our results indicated that the availability of specific PDGF isoforms and the relative expression of each receptor gene product appear to be major determinants of the PDGF response. An understanding of the mechanisms by which the expression of PDGF and their receptors on vascular smooth muscle cells are regulated will give greater insights as to how these gene products are involved in atherosclerosis.     

Interaction of receptors for insulin-like growth factor I, platelet-derived growth factor, and fibroblast growth factor in rat aortic cells

Serum contains various growth factors which regulate the proliferation of cells. We investigated the growth of cultured arterial smooth muscle cells under the influence of insulin-like growth factor I (IGF I), fibroblast growth factor (FGF), and platelet-derived growth factor (PDGF), and examined the effect of these growth factors on the binding of [125I] IGF I and on the binding of [125I]PDGF to these cells. IGF I, FGF, and PDGF stimulated [6-3H]thymidine incorporation into DNA of confluent cultures of cells which were incubated in modified Dulbecco's modified Eagle medium. However, the effect of these growth factors on DNA synthesis was much more potent in Dulbecco's modified Eagle medium with 1% fetal calf serum. FGF and PDGF potentiated the growth-promoting effect of IGF I. The binding of [125I]IGF I to the cells was increased after a preincubation with FGF and PDGF. The binding was potently increased by FGF (100 ng/ml) after a preincubation time of 30 min. There was an increase in binding during the first 3 h of preincubation followed by a decrease after 4-5 h. PDGF (10-1000 ng/ml) stimulated [125I]IGF I binding only after 2 h of preincubation. The stimulation was dose dependent. Maximal stimulation of the binding was observed after 3 h of preincubation followed by a decrease after 4-5 h of preincubation. Specific binding sites for PDGF on smooth muscle cells could be demonstrated too. A preincubation of confluent cells with IGF I caused a dose-dependent increase in [125I]PDGF binding. These results support the hypothesis that the regulation of the binding of a specific growth factor by a second growth factor is important for the control of cell growth.     

Apelin与心血管疾病关系的研究进展

Apelin为新近发现的一种脂肪细胞因子,是孤儿G蛋白耦联受体APJ(即血管紧张素样受体1相关的受体蛋白)独特的内源性配体。Apelin-APJ系统在机体内广泛分布,包括心血管系统,可促进一氧化氮生成,具有扩张外周血管、正性肌力和调节体液平衡等多种重要的生物学功能。现就Apelin结构分布及其在心血管疾病领域中的相关研究做一综述。     

Human microvascular endothelial cells express receptors for platelet-derived growth factor.

Endothelial cells have been widely thought to be unresponsive to platelet-derived growth factor (PDGF, a major growth factor released from stimulated platelets at the sites of vascular insults) and devoid of PDGF receptors. Nevertheless, in examining the growth-factor responses of microvascular endothelial cells isolated from human omental adipose tissue, we were surprised to detect PDGF-induced tyrosine phosphorylation of a 180-kDa glycoprotein, subsequently identified as the cellular receptor for PDGF by specific immunoprecipitation. Scatchard analysis of 125I-labeled PDGF binding to human microvascular endothelial cells revealed 30,000 PDGF receptors per cell with a Kd of 0.14 nM. PDGF stimulated tyrosine phosphorylation of PDGF receptors and other cellular proteins in a dose- and time-dependent manner, with half-maximal receptor phosphorylation occurring at 0.3 nM recombinant human PDGF (B chain) and a less than or equal to 1-min exposure to PDGF. Normal cellular consequences of receptor activation were also observed, including tyrosine phosphorylation of a 42-kDa protein and serine phosphorylation of ribosomal protein S6. Furthermore, PDGF was mitogenic for these cells. Microvascular endothelial cells play a central role in neovascularization required for wound healing and solid tumor growth. Thus, the discovery of functional PDGF receptors on human microvascular endothelial cells suggests a direct role for PDGF in this process.     

Chromatin binding of epidermal growth factor, nerve growth factor, and platelet-derived growth factor in cells bearing the appropriate surface receptors.

We analyzed the uptake and intracellular distribution of 125I-labeled epidermal growth factor, nerve growth factor, and platelet-derived growth factor in different cell lines that express or do not express the respective surface receptors for these factors. After 1 hr of incubation, all three growth factors were detected in the cytoplasmic fraction and in the nucleus, tightly bound to chromatin. The amount of chromatin-bound growth factors continued to increase during the incubation, and analysis at 48 hr revealed each chromatin-bound labeled growth factor in a nondegraded form. After limited digestion of chromatin with DNase II (10-20% digested sequences), specific release of all three growth factors was detected only after 1 hr of incubation but not after 24 and 48 hr, suggesting that the DNA regions involved in growth factor binding became nuclease-resistant. Binding of labeled epidermal growth factor and nerve growth factor to isolated chromatin was inhibited by monoclonal antibodies specific for the respective growth factor receptor. The data suggest that chromatin binding may represent an important step in the pathway of growth factor action.     

生长分化因子15在心血管疾病中的研究进展

生长分化因子15（GDF-15）是细胞因子超家族转化生长因子-β中的成员。在生理条件下GDF-15在心肌中呈弱表达,而在诸多病理条件下其表达水平增加。越来越多的证据表明,GDF-15水平升高是心血管疾病的一种很有价值的预后标志物。此外,GDF-15对心肌细胞具有内源性抗肥厚和拮抗心脏缺血／再灌注损伤的性质。GDF-15正在成为评估和管理心脏病患者的一种很有前途的生物学标志物,并对心肌细胞具有潜在的保护作用。     

In vivo activation of rat aortic platelet-derived growth factor and epidermal growth factor receptors by angiotensin II and hypertension

It is unclear whether the previous in vitro evidence of a link between angiotensin II (Ang II) and growth factor receptors can apply to the in vivo situation. In this study, we examined vascular platelet-derived growth factor (PDGF) and epidermal growth factor (EGF) receptor activation in stroke-prone spontaneously hypertensive rats (SHRSP) and the role of Ang II. Tyrosyl phosphorylation of the growth factor receptors was determined by Western blot analysis coupled with immunoprecipitation. Tyrosyl phosphorylation of the aortic PDGF beta-receptor, but not the EGF receptor, was chronically increased in SHRSP with hypertension, compared with normotensive rats, being accompanied by increased extracellular signal-regulated kinase (ERK) activity. Treatment of SHRSP with ACE inhibitors (perindopril or enalapril) significantly reduced aortic PDGF beta-receptor tyrosyl phosphorylation and ERK activity, whereas treatment with hydralazine failed to reduce these activities. Therefore, these aortic changes in SHRSP were mediated by Ang II in response to vascular ACE. Ang II was infused into rats to examine the effects on aortic growth factor receptors. Chronic Ang II infusion, via the angiotensin type 1 receptor, significantly increased activation of the aortic PDGF beta-receptor but not the EGF receptor. Thus, the aortic PDGF beta-receptor, activated by ACE-mediated Ang II, seems to be responsible for vascular remodeling in hypertensive rats.     

Protease-activated receptors in cardiovascular diseases

Thrombosis associated with the pathophysiological activation of platelets and vascular cells has brought thrombin and its receptors to the forefront of cardiovascular medicine. Thrombin signaling through the protease-activated receptors (PARs) has been shown to influence a wide range of physiological responses including platelet activation, intimal hyperplasia, inflammation, and maintenance of vascular tone and barrier function. The thrombin receptors PAR1 and PAR4 can be effectively targeted in animals in which acute or prolonged exposure to thrombin leads to thrombosis and/or restenosis. In the present study, we describe the molecular and pharmacological basis of small-molecule inhibitors that target PAR1. In addition, we discuss a new class of cell-penetrating inhibitors, termed pepducins, that provide insight into previously unidentified roles of PAR1 and PAR4 in protease signaling.     

Toll-like receptors in cardiovascular diseases

The Toll-like receptor family recognizes mostly exogenous ligands like bacterial lipopolysaccharides or DNA and activates the inflammatory cell. Evidence is accumulating that these Toll-like receptors are important in cardiovascular pathologies. Recently, expression of Toll-like receptors in arterial and myocardial cells has been shown and mouse knockout and human studies on polymorphisms point to a role of Toll-like receptor 4 in neointima formation and atherosclerosis. It is now becoming clear that these receptors not only serve as receptors for pathogen-associated molecular patterns but are also involved in the initiation and progression of cardiovascular pathologies.