Intestinal smooth muscle cell maintenance by basic fibroblast growth factor

Intestinal tissue engineering is a potential therapy for patients with short bowel syndrome. Tissue engineering scaffolds that promote smooth muscle cell proliferation and angiogenesis are essential toward the regeneration of functional smooth muscles for peristalsis and motility. Since basic fibroblast growth factor (bFGF) can stimulate smooth muscle proliferation and angiogenesis, the delivery of bFGF was employed to stimulate proliferation and survival of primary intestinal smooth muscle cells. Two methods of local bFGF delivery were examined: the incorporation of bFGF into the collagen coating and the encapsulation of bFGF into poly(D,L-lactic-co-glycolic acid) microspheres. Cell-seeded scaffolds were implanted into the omentum and were retrieved after 4, 14, and 28 days. The seeded cells proliferated from day 4 to day 14 in all implants; however, at 28 days, significantly higher density of implanted cells and blood vessels was observed, when 10 microg of bFGF was incorporated into the collagen coating of scaffolds as compared to scaffolds with either no bFGF or 1 microg of bFGF in collagen. Microsphere encapsulation of 1 microg of bFGF produced similar effects as 10 microg of bFGF mixed in collagen and was more effective than the delivery of 1 microg of bFGF by collagen incorporation. The majority of the implanted cells also expressed alpha-smooth muscle actin. Scaffolds coated with microsphere-encapsulated bFGF and seeded with smooth muscle cells may be a useful platform for the regeneration of the intestinal smooth muscle.     

Expression of acidic and basic fibroblast growth factors in human and bovine vascular smooth muscle cells

The expression and synthesis of acidic and basic fibroblast growth factors (aFGF and bFGF) in cultures of bovine and human vascular smooth muscle cells (BSMC and HSMC) was studied. BSMC express and synthesize only bFGF, whereas HSMC express and synthesize both bFGF and aFGF. The presence of bFGF in BSMC is shown by the following criteria: (1) the growth factor activity in BSMC lysates binds to a heparin-affinity column and elutes as a single peak at 1.5-1.7 M NaCl, characteristic for bFGF; (2) this extract is mitogenic for smooth muscle cells; (3) Northern blot analysis demonstrates three distinct bFGF mRNAs of 7.0, 4.0, and 1.9 kb; no aFGF mRNA species were detected. Analysis of human umbilical vein endothelial cells yielded similar results: Heparin-affinity chromatography and Northern blot analysis failed to demonstrate the presence of aFGF despite the detection of bFGF by these techniques. In contrast, HSMC synthesize two growth factor activities: First, they bind to an immobilized heparin column and elute as two separate peaks at 1.2 and 1.5-1.7 M NaCl, characteristic for aFGF and bFGF; and second. Northern blot analysis demonstrates the expression of aFGF mRNA of 4.6 kb and bFGF mRNAs of 7.0, 4.0 and 1.9 kb. Furthermore, it is shown that aFGF and bFGF are potent mitogens for smooth muscle cells in vitro.     

肺炎衣原体感染对血管平滑肌细胞黏附和迁移的影响

目的:观察肺炎衣原体(C.pn)感染对血管平滑肌细胞(VSMCs)黏附和迁移的影响。方法:C.pn在人喉癌细胞系HEp-2细胞中增殖培养后感染大鼠VSMCs,吖啶橙(AO)荧光染色观察细胞内C.pn包涵体的形态特点;聚合酶链反应(PCR)检测C.pn特异性DNA片段;细胞黏附实验观察C.pn感染对VSMCs黏附能力的影响;wound-healing assay和Transwell assay检测C.pn感染VSMCs后细胞迁移能力的改变。结果:C.pn感染VSMCs后,少数细胞内出现空泡状结构即包涵体,但在多数细胞内以点状感染灶形式存在,包涵体较大,但数量较少。利用PCR可在感染的VSMCs内检测到437 bp的C.pn特异性DNA片段。细胞黏附实验结果显示,C.pn感染VSMCs 2 h后,细胞黏附能力明显增强,其吸光度值明显高于正常对照组(P0.01),细胞黏附率为134.38%。Wound-healing assay结果显示,C.pn感染VSMCs 24 h后,细胞向划痕中央迁移的距离明显大于正常对照组(P0.05)。Transwell assay结果显示,C.pn感染VSMCs 24 h后,C.pn感染组的细胞迁移数明显多于正常对照组(P0.01)。结论:C.pn感染能够显著增强VSMCs的黏附和迁移能力。     

碱性成纤维细胞生长因子对人脑动静脉畸形血管平滑肌细胞增殖和表达骨桥蛋白的影响

目的：研究碱性成纤维细胞生长因子（bFGF）对体外培养的人脑动静脉畸形（CAVM）血管平滑肌细胞（VSMC）增殖和表达骨桥蛋白的影响。方法： 应用胶原酶消化法培养人CAVM的VSMC，MTT法检测VSMC的增殖，免疫印迹法检测VSMC骨桥蛋白的表达。结果：bFGF作用于VSMC后，细胞增殖活性明显增加。实验组骨桥蛋白的表达显著高于对照组 (P<0.05)。结论： 体外条件下，bFGF可以刺激CAVM的VSMC增殖，并能促进其表达骨桥蛋白。     

佛波酯敏感的PKC介导IL-6上调大鼠血管平滑肌细胞bFGF蛋白表达

目的:观察蛋白激酶C(PKC)途径在白细胞介素 6(IL-6 )上调大鼠血管平滑肌细胞(VSMC)碱性成纤维细胞生长因子(bFGF)中的作用。方法:采用大鼠主动脉贴块法培养VSMC,以佛波醇 12,13-二丁酸盐预耗竭细胞内PKC,Western免疫印迹法观察IL-6对VSMCbFGF和成纤维细胞生长因子 1型受体蛋白表达的影响。结果:IL-6在 0-10 0g/L剂量范围内上调bFGF蛋白,并呈量效关系,表达高峰为 2 4h。细胞内佛波酯敏感的PKC预耗竭后该上调作用显著下降。IL-6对VSMC成纤维细胞生长因子 1型受体蛋白表达无影响。结论:IL-6上调大鼠VSMCbFGF蛋白水平,上调作用呈佛波酯敏感的PKC依赖性.     

Probucol对碱性成纤维细胞生长因子和过氧化氢促大鼠血管平滑肌细胞增殖的影响

目的:研究probucol对bFGF和H₂O₂促大鼠血管平滑肌细胞(VSMC)增殖的影响。方法:采用MTT、细胞计数和[3H]-TdR掺入法观察probucol对bFGF和H₂O₂促VSMC增殖的影响。结果:①Probucol抑制bFGF和H₂O₂刺激VSMC增殖和DNA合成,且呈剂量依赖性。Probucol+bFGF和probucol+H₂O₂组与bFGF和H₂O₂组比较,细胞计数、A值和[3H]-TdR掺入量分别下降了40.0%、39.1%、45.5%和46.9%、45.0%、39.5%(P＜0.05,P＜0.01)。②bFGF和H₂O₂刺激前给予probucol预处理24h能显著抑制VSMC增殖和DNA合成(P＜0.05),而bFGF和H₂O₂刺激后24h给予probucol则无明显影响(P＞0.05)。结论:Probucol能显著抑制bFGF和H₂O₂刺激的VSMC增殖和DNA合成,但对bFGF和H₂O₂预刺激诱导的细胞增殖无抑制作用。     

肺炎衣原体感染致血管平滑肌细胞的改变

肺炎衣原体感染是动脉粥样硬化发生的重要危险因素。肺炎衣原体可以感染血管壁内皮细胞、平滑肌细胞、单核细胞/巨噬细胞,并与这些细胞之间相互作用,影响这些细胞的形态与功能,从而参与动脉粥样硬化发生发展。在动脉粥样硬化发病机制中,平滑肌细胞形态功能的变化与动脉粥样硬化密切相关,肺炎衣原体能够感染平滑肌细胞,影响平滑肌细胞在血管内的生理生化特征,促进动脉粥样硬化的发展过程。     

Chlamydia pneumoniae facilitates monocyte adhesion to endothelial and smooth muscle cells

Chlamydia pneumoniae has been linked to atherosclerotic heart disease. However, there is a limited knowledge by which C. pneumoniae gain access to atheromatous lesions. The adhesion of C. pneumoniae -infected circulatory component(s) to endothelium and smooth muscle cells represents the first step in an inflammatory response. We examined the ability of viable as well as heat inactivated C. pneumoniae to infect human monocytes and subsequently the ability of infected monocytes to adhere to human coronary artery endothelial cells (HCAEC) and human coronary smooth muscle cells (HCSMC). Our results demonstrate susceptibility of monocytes to in vitro chlamydial infection. Inclusions of varying sizes and intensities were observed 3-5 days after inoculation with viable C. pneumoniae. Monocytes infected with heat inactivated organisms revealed no inclusions, in keeping with the observations of uninfected monocytes. Moreover, monocytes infected with viable C. pneumoniae adhered preferentially to HCAEC and HCSMC, as compared to uninfected monocytes or monocytes harbouring heat inactivated Chlamydia.     

Angiotensin II induces proliferation of human cerebral artery smooth muscle cells through a basic fibroblast growth factor (bFGF) dependent mechanism

Remodeling of cerebral arteries in hypertension produces thickened vessel walls associated with atherosclerotic plaque formation. In both thickening and plaque formation, proliferation of vascular smooth muscle cells is a hallmark. Genetically hypertensive rats treated with an angiotensin II (Ang II) AT1 receptor antagonist inhibited thickening of cerebral arteries suggesting a mitogenic action of Ang II on cerebral arterial VSMC (CVSMC). However, in studies using smooth muscle cells cultured from peripheral arteries, Ang II causes cell hypertrophy, but not proliferation. We determined the effect of Ang II on proliferation of cultured human CVSMC. CVSMC were cultured from the basilar artery obtained at autopsy. Ang II (10(-7) M) stimulated proliferation determined by counting cells and mitochondrial activity assay. Synthesis and release of basic fibroblast growth factor (bFGF) was essential for Ang II-stimulated proliferation. These findings are consistent with the notion that Ang II stimulates CVSMC proliferation thereby contributing to vessel remodeling.     

Chlamydia pneumoniae uses the mannose 6-phosphate/insulin-like growth factor 2 receptor for infection of endothelial cells

Several mechanisms for attachment and entry of Chlamydia have been proposed. We previously determined that the major outer membrane protein of Chlamydia trachomatis is glycosylated with a high-mannose oligosaccharide, and a similar structure inhibited the attachment and infectivity of C. trachomatis in epithelial cells. Because insulin-like growth factor 2 (IGF2) was shown to enhance the infectivity of Chlamydia pneumoniae but not C. trachomatis in endothelial cells, a hapten inhibition assay was used to analyze whether the mannose 6-phosphate (M6P)/IGF2 receptor that also binds M6P could be involved in infection of endothelial cells (HMEC-1) by Chlamydia. M6P and mannose 6-phosphate-poly[N-(2-hydroxyethyl)-acrylamide] (M6P-PAA) inhibited the infectivity of C. pneumoniae AR-39, but not C. trachomatis serovar UW5 or L2, while mannan inhibited the growth of C. trachomatis, but not C. pneumoniae. Using metabolically labeled organisms incubated with cells at 4 degrees C (organisms attach but do not enter) or at 37 degrees C (organisms attach and are internalized), M6P-PAA was shown to inhibit attachment and internalization of C. pneumoniae in endothelial cells but did not inhibit attachment or internalization of C. trachomatis serovar E or L2. These findings indicate that C. pneumoniae can utilize the M6P/IGF2 receptor and that the use of this receptor for attachment and entry differs between C. pneumoniae and C. trachomatis.     

白藜芦醇上调碱性成纤维细胞生长因子、胰岛素样生长因子1表达治疗骨骼肌损伤

文题释义： 白藜芦醇：非黄酮类的多酚化合物,分子式为C₁₄H₁₂O₃,相对分子质量228.25,为白色针状晶体,易溶于乙醚、氯仿、甲醇、乙醇、丙酮、乙酸、乙酯等有机溶剂。别名：3,4',5-三羟基芪、虎杖甙元,是相关植物在受到病菌侵染或环境恶化时产生的植物抗毒素,主要存在于葡萄、虎杖、决明、花生、桑葚等植物中。 骨骼肌急性钝挫伤：钝挫伤指在钝器作用下,造成以皮内或皮下及软组织出血为主要改变的闭合性损伤。骨骼肌急性钝挫伤指钝器在短时间内伤到肌肉层造成皮下及软组织出血,肌肉没有断裂或者撕裂的闭合性损伤。临床上90%的骨骼肌损伤属于钝挫伤与扭伤。 背景：近年来国内外对白藜芦醇抑制机体组织纤维化方面做了大量研究,但其在肌组织损伤康复方面的作用却鲜有报道。 目的：观察骨骼肌急性钝挫伤修复过程中碱性成纤维细胞生长因子、胰岛素样生长因子1蛋白表达规律,探讨白藜芦醇促进受损骨骼肌结构与功能恢复的作用机制。 方法：33只新西兰兔随机分为3组：正常组(3只)、自然恢复组(15只)、白藜芦醇组(15只),除正常组外均采用钝性暴力法制造骨骼肌钝挫伤模型,损伤后自然恢复组不予处理,白藜芦醇组给予白藜芦醇灌胃治疗,分别于伤后1,3,7,14,21 d处死动物,采用苏木精-伊红染色、Masson染色观察炎症细胞浸润情况、胶原纤维形成情况,免疫组织化学、免疫印记法检测骨骼肌中碱性成纤维细胞生长因子、胰岛素样生长因子1蛋白表达。 结果与结论：①苏木精-伊红染色显示：正常组兔肌纤维多边形、形态规则、排列紧密,肌核均匀分布于肌膜下,无增生与固缩,肌膜完整;自然恢复组伤后1 d见血细胞渗出,3 d炎症细胞开始浸润,至7 d达峰值,21 d肌纤维形态基本恢复正常;白藜芦醇组在炎症细胞浸润、修复时间上整体优于自然恢复组;②Masson染色显示：正常肌细胞中胶原纤维含量极少;自然恢复组随着瘢痕组织的形成,胶原纤维逐渐增加,于14 d达高峰;白藜芦醇组胶原纤维含量低于自然恢复组;③免疫组织化学和免疫印记检测显示：碱性成纤维细胞生长因子、胰岛素样生长因子1蛋白在骨骼肌修复过程中呈现先升高后降低的变化规律,两组均于7 d达高峰,21 d时仍高于正常,且白藜芦醇组峰值高于自然恢复组;④整体来看,白藜芦醇组在炎症反应以及修复程度上均优于自然恢复组,白藜芦醇通过上调碱性成纤维细胞生长因子、胰岛素样生长因子1蛋白表达来促进骨骼肌修复,但其并不改变骨骼肌损伤修复过程中蛋白表达量的整体变化规律。 ORCID: 0000-0001-6570-2052(刘杏) 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

Subcellular distribution of basic fibroblast growth factor in human hepatoma cells.

The subcellular distribution of endogenous basic fibroblast growth factor (bFGF) was studied in the human hepatoma cell line, SK Hep-1. Basic FGF was demonstrated in cytosol, nuclei, and membranes by purification from each subcellular fraction using ion-exchange chromatography and heparin-affinity chromatography, and by the detection of bFGF-immunoreactive proteins on Western blots of heparin-affinity purified samples. About 65% of bFGF bioactivity was present in cytosol, 17% in nuclei, and 18% in membranes. Antisera raised against either recombinant 18 kDa bFGF or a bFGF N-terminal extension peptide showed that cytosol contained bFGF of mainly Mr 18,000 whereas nuclei and membranes contained three forms of bFGF of Mr 18,000, 22,500, and 24,000. Mitogenic activity in nuclei was chromatin-associated and required 0.6 M NaCl or 100 micrograms/ml heparin for maximal release. Membrane-bound activity was released by 0.6 M NaCl but not by heparin. The finding that endogenous bFGF proteins are present in various subcellular compartments suggests that bFGF may have additional biological roles at these sites.     

Endothelial cells synthesize basic fibroblast growth factor and transforming growth factor beta

Endothelial cells, including human umbilical vein endothelial cells (HUVEC), bovine aortic endothelial cells (BAEC), and bovine capillary endothelial cells (BCEC) in culture synthesize basic fibroblast growth factor (bFGF) and transforming growth factor type beta (TGF-beta). Basic FGF was cell-associated and synthesis was demonstrated by (i) the presence of bFGF mRNA species, (ii) binding to heparin-Sepharose and elution at 1.5 M NaCl, (iii) cross-reactivity with anti-bFGF antibodies when analyzed by electrophoretic blotting, and (iv) biological activity. Basic FGF was found in cell lysates at 2.3 ng/10(6) cells in HUVEC, 2.0 ng/10(6) cells in BCEC, and 13 ng/10(6) cells in BAEC. TGF-beta was secreted into media, and synthesis was demonstrated by (i) presence of TGF-beta mRNA species, (ii) cross-reactivity with anti-TGF-beta antibodies when analyzed by immunoprecipitation, (iii) competitive binding with authentic human platelet-derived TGF-beta that was blocked by TGF-beta specific blocking antibodies, and (iv) inhibition of [3H]TdR incorporation in CCl-64 cells. TGF-beta was secreted in an inactive form and required acid activation for detection. HUVEC synthesized 2.0 ng TGF-beta/10(6) cells per 12 hr; BCEC, 3.5 ng; and BAEC, 3.5 ng. HUVEC proliferation was not affected by treatment with exogenous TGF-beta, while BCEC proliferation was decreased by treatment with TGF-beta. Vascular endothelium is thus a source for these two potent multifunctional regulatory molecules, both of which may affect the growth of endothelium and neighboring fibroblasts, smooth muscle cells and white blood cells. The activation or release of these factors by endothelium may be a precipitating event in important cellular processes such as wound healing, organogenesis, and angiogenesis.     

Monoclonal antibodies against human basic fibroblast growth factor

Recombinant human basic fibroblast growth factor (hbFGF) was used as an antigen to develop, by a somatic cell fusion technique, four monoclonal antibodies (MAbs), that recognize the complete and amino-terminal truncated form of hbFGF. Isotype identification showed that MAbs designated MAb12 and MAb98 were IgG1; and those designated MAb52 and MAb78 were IgG2b. All these MAbs bound the complete form of hbFGF produced in E.coli. Competition with synthetic polypeptides, a replication of 1-9 aa and of 141-146 aa of hbFGF, and truncated forms of hbFGF by 13 and 40 amino acid residues in its amino-terminal produced in E. coli by recombinant technique, revealed at least two epitopes recognized by the four IgG type MAbs. MAb12 and MAb78 recognized the epitope located within the first 9 amino acid residues at the amino terminal of the complete hbFGF. MAb52 and MAb98 recognized the one located between the amino acid residue no. 14 and 40. None of MAbs bound bovine acidic FGF (aFGF). Using MAb52 or MAb98 and MAb78, a two-site EIA has been developed. This EIA is sensitive enough to detect 0.5 ng/ml of hbFGF. Furthermore, MAb78 was used as a ligand for affinity chromatography to purify hbFGF mutein CS4, which binds weakly to a heparin affinity column.     

Basic fibroblast growth factor regulates type I collagen and collagenase gene expression in human smooth muscle cells.

Basic fibroblast growth factor (bFGF) is a multifunctional peptide well known for angiogenic, neurotropic, and mesoderm-inducing effects. In the present study, we have investigated the effects of bFGF on collagen and collagenase gene expression in human iliac arterial smooth muscle cells. We report that bFGF inhibits type I collagen gene expression and collagen biosynthesis, with concomitant stimulation of collagenase gene expression. The smooth muscle cells incubated with human recombinant bFGF decreased the mRNA steady state levels of pro-alpha 1(I) type I collagen by as much as 72%. [3H]Hydroxyproline synthesis was also suppressed by 59% compared with untreated control cultures. Indirect immunofluorescence confirmed corresponding changes at the protein level. In contrast to the down-regulation of type I collagen gene expression, collagenase gene expression was found to be up-regulated severalfold by bFGF. The data suggest that bFGF is capable of regulating collagen and collagenase gene expression divergently in human smooth muscle cells and that the effects appear to be mediated at a pretranslational level.