连接蛋白43在培养心肌肥大时的表达及其意义

目的研究培养心肌连接蛋白４３（Ｃｘ４３）的表达及与心肌肥大的关系。方法分离培养大鼠心肌细胞,用去甲肾上腺素（ＮＥ）或苯肾上腺素（ＰＥ）诱导心肌肥大,用免疫组化方法观察心肌细胞Ｃｘ４３、增殖细胞核抗原（ＰＣＮＡ）及ｃｄｃ２表达,以图像分析系统检测Ｃｘ４３表达量的变化。结果在培养中加ＮＥ或ＰＥ的心肌细胞,Ｃｘ４３表达明显低于对照组,而其ＰＣＮＡ的阳性率明显高于对照组。ｃｄｃ２阳性率不变。结论在ＮＥ或ＰＥ作用下,培养大鼠心肌细胞中Ｃｘ４３表达下降,与细胞进入Ｓ期有关,这可能是两者促进心肌肥大的机制     

发育大鼠心肌细胞间隙连接蛋白43表达特性

目的：探讨大鼠心肌细胞间隙连接蛋白43(Cx43)表达的发育特性。方法：应用SP免疫组化和图像分析方法,观察胎大鼠、出生1 d、5 d、10 d和25 d大鼠心肌细胞Cx43的蛋白表达。结果：(1)胎鼠心肌细胞Cx43呈斑点状遍布于心肌细胞侧—侧连接、细胞质内和闰盘处。(2)出生后1 d大鼠心肌细胞的Cx43分布与胎鼠相似,5 d和10 d组逐渐向闰盘处聚集。25 d时部分已聚集于端闰盘处,其余仍呈斑点状散在分布。(3)出生前后心室肌细胞Cx43分布有差异。分布密度总规律是：胎大鼠＞出生1 d＞5 d＞10 d＞25 d。结论：出生前后大鼠心肌细胞Cx43分布随心脏发育逐渐向闰盘处重排,其分布密度呈逐渐下降趋势。     

Altered expression of connexin43 and phosphorylation connexin43 in glioma tumors

In this study, we aim to evaluate the connexin (Cx43) and phosphorylation Cx43 (p-Cx43) expression of human glioma tumors and correlate their expression with degrees of malignancy and proliferation, apoptosis, and migration activity of tumors. Cx43 and p-Cx43 expression were examined by Western blot analysis and immunohistochemical staining. The U251 cell viability was measured by MTT analysis. The apoptosis and migration were also evaluated by flow cytometric analysis and fluoroblok transwell chambers, respectively. We found that the Cx43 expression were significantly downregulated in in malignant glioma (WHO grade III and IV), compared to the malignant glioma (WHO grade I and II) and the p-Cx43 expression levels of malignant glioma (WHO grade III and IV) were significantly increased (P<0.05), compared to the malignant glioma (WHO grade I and II) at immunohistochemical analysis. After treatment of cells with a specific inhibitor of PKC, MAPK, and PTK inhibitors, the cell viability and migration were significantly decreased, while the apoptosis was slightly induced. In conclusion, the Cx43 expression level is inversely correlated with the tumor grade and proliferation and migration activity of tumor. Higher p-Cx43 expression level in high tumor grade suggests that a complex mechanism is involved in the suppression of tumor growth by connexins.     

连接蛋白43在小鼠胚胎心的时空表达规律

目的:探讨连接蛋白43 (Cx43)在小鼠胚胎心的时空表达规律及意义.方法:用抗Cx43、抗心肌肌球蛋白重链(MHC)和抗横纹肌肌节肌动蛋白(α-SCA)对胚龄9～17 d小鼠胚胎心连续切片进行免疫组织化学或免疫荧光显色;免疫印迹检测胚龄11、13、15、16d和17d小鼠胚胎心组织中Cx43的含量变化.结果:胚龄9～10 d,仅在左心室腹侧壁及原始小梁最先检测到Cx43弱阳性表达.随着发育,Cx43在心房心室阳性范围逐渐扩展,阳性表达逐渐增强.而在某些特定部位,如窦房结、房室管、房室结和房室束等始终未见Cx43阳性染色.结论:Cx43在胚胎心的时空表达模式与心工作心肌和传导系心肌的发育及兴奋传导功能相适应.     

ndrg2 mRNA在人胎脑组织中表达的时空特点

本研究利用反转录-聚合酶链式反应(RT-PCR)检测了ndrg2 mRNA在人胎脑组织中表达的时空特点,为进一步研究其功能提供实验依据。收集正常引产16～28周人胎脑组织标本,进行总RNA提取,应用RT-PCR方法半定量分析ndrg2基因在上述人胎脑组织中的表达水平和变化规律。RT-PCR结果显示:ndrg2 mRNA在正常人胎脑16、20、24和28周的各脑功能区均有表达,但随着发育,其表达水平有差别。在小脑、延髓和海马等部位,ndrg2 mRNA的表达水平在16周胎脑中较高。而在额叶和顶叶等部位,ndrg2 mRNA的表达水平在28周胎脑中达到高峰。以上结果表明,在人胚脑发育过程中ndrg2 mRNA从16～28周均有表达,但在不同脑后其表达存在一定差异,提示ndrg2基因对中枢神经系统的发育和成熟可能有重要影响。     

JAM-A expression during embryonic development.

Cell adhesion molecules of the immunoglobulin superfamily play an important role in embryonic development. We have shown recently that JAM-A, a member of this family expressed at endothelial and epithelial tight junctions, is involved in platelet activation, leukocyte transmigration, and angiogenesis. Here, we determine the expression pattern of the JAM-A gene during embryogenesis using transgenic mice expressing lacZ under the control of the endogenous JAM-A promoter. Histochemical staining for beta-galactosidase in heterozygous mouse embryos was first seen in the inner cell mass and trophectoderm of the blastocyst. By 8.5 days post coitum (dpc), JAM-A gene activity was detected in the endoderm and part of the surface ectoderm. At 9.5 dpc, JAM-A expression began to localize to certain organ systems, most notably the developing inner ear and early vasculature. Localization of JAM-A to embryonic vasculature was confirmed by double-staining with antibodies against JAM-A and platelet endothelial cell adhesion molecule-1, a known endothelial cell marker. As organogenesis progressed, high levels of JAM-A expression continued in the epithelial component of the inner ear as well as the epithelium of the developing skin, olfactory system, lungs, and kidneys. In addition, JAM-A gene activity was found in the developing liver, choroid plexuses, and gut tubes. Immunofluorescent staining with a JAM-A antibody was performed to confirm that expression of the JAM-A-beta-galactosidase fusion protein accurately represented endogenous JAM-A protein. Thus, JAM-A is prominently expressed in embryonic vasculature and the epithelial components of several organ systems and may have an important role in their development.     

脂联素对大鼠缺血再灌注心肌缝隙连接蛋白43表达的影响

目的: 观察脂联素(APN)对大鼠缺血再灌注心肌缝隙连接蛋白43(Cx43)表达的影响,进一步探讨其抗心律失常的可能机制。方法: 将48只雄性Wistar大鼠随机分成:(1)假手术 (SM)组;(2)缺血再灌注(I/R)组:结扎冠状动脉左前降支,30 min后松开结扎线,再灌注120 min;(3)脂联素+缺血再灌注组1(I/R+APN1):先阻断血流30 min,于再灌注120 min开始时给予3.5 μg/kg APN;(4)脂联素+缺血再灌注组2(I/R+APN2):缺血前10 min给予3.5 μg/kg APN,余同I/R组。观察各组心律失常的发生情况;应用RT-PCR观察各组心室肌细胞 Cx43 基因表达;用免疫组织化学方法观察Cx43分布的变化;应用硫代巴比妥酸(TBA)法和黄嘌呤氧化酶法测各组动物血清中丙二醛(MDA)的含量和超氧化物歧化酶(SOD)的活性;用RT-PCR及Western blotting法分析内皮型一氧化氮合酶(eNOS)mRNA及蛋白的表达,用电镜观察各组心室肌超微结构的改变。结果: (1)I/R组与SM组比较,心律失常评分和血清MDA含量显著增高(P<0.01),SOD活性降低(P<0.01);心室肌Cx43表达明显减少,差异有统计学意义(P<0.01),Cx43分布紊乱,失去正常的规律性;心肌细胞超微结构有明显损伤;心室肌eNOS mRNA及蛋白的表达明显降低,差异有统计学意义(P<0.01)。(2)无论缺血前还是缺血后使用脂联素处理,与I/R组相比,心律失常评分显著降低(P<0.01);Cx43及eNOS表达增高(P<0.01),Cx43分布紊乱的程度减轻;心肌细胞超微结构损伤明显改善。结论: APN可能通过氧化应激调节Cx43的功能,从而发挥抗缺血/再灌注心律失常的作用。     

Connexin43基因在宫颈癌细胞系HeLa中的瞬时表达

目的 探讨细胞间隙连接基因connexin43在宫颈癌细胞系HeLa中的表达以及对该细胞生长的影响。方法 应用流式细胞术（ＦＣＭ）研究connexin43基因在ＨeLa细胞中的表达，以及对生长抑制及细胞增殖周期的影响。结果 connexin43基因表达阳性的细胞计数率由０．７％上升至２６．５％，细胞生长明显受抑。结论 connexin43基因可能是潜在的肿瘤抑制基因。     

Expression of cVg1 mRNA during chicken embryonic development

Using degenerated PCR-primers to identify known and novel BMPs that are expressed in the developing chicken heart, we identified not only BMP2, -4, and -7 mRNA, but also the TGFbeta superfamily member cVg1. The expression pattern of cVg1 mRNA was determined during chicken development from HH4 to HH44. In early developmental stages, cVg1 mRNA is expressed in the primitive streak, paraxial mesoderm, developing somites, and developing neural tube. Subsequently, cVg1 mRNA is expressed in the developing central and peripheral nervous system, retina, auditory vesicle, notochord, lung alveoli, and olfactory mucosa. In the heart, cVg1 is initially expressed through the linear heart tube, but becomes restricted to the forming chamber myocardium, in an expression domain similar to that of atrial natriuretic factor (ANF) mRNA.     

新生儿心肌连接蛋白43、45的表达

目的　研究新生儿心肌不同部位连接蛋白 4 3、4 5 (Cx4 3、Cx4 5 )表达的差异。方法　应用SP免疫组化方法 ,分析和比较 6例新生儿心不同腔室心肌细胞Cx4 3、Cx4 5的表达。结果　 1 新生儿心肌Cx4 3的蛋白表达在心四个腔均有表达 ,呈斑点状遍布于整个心房肌和心室肌的细胞质内和细胞膜表面 ,少数位于闰盘处 ;Cx4 3、主要在心室肌表达 ,心房较少 ;2 Cx4 3与Cx4 5的分布类似 ,但远少于Cx4 3。结论　Cx4 3主要分布于新生儿心肌细胞质内和细胞表面。心室表达多于心房 ,Cx4 5和Cx4 3分布相似 ,但不如Cx4 3丰富。     

Ischaemia-induced temporal expression of connexin43 in rat heart

 To investigate the regulation of cell-to-cell coupling in myocardial ischaemia, the three-dimensional expression of connexin43 (Cx43) during experimental ischaemia was examined using a confocal laser scanning microscope. After induction of myocardial infarction in rats, serial optical sections were obtained from the left ventricular myocardium at various times (3 h to 60 days after ligation). The expression of Cx43 was detected immunohistochemically with FITC-labelled anti-rat Cx43 antibody. Fluorescent dots of Cx43 remained along the intercalated disc and decreased in number around the infarct up to 12 h after ligation. Cx43-expression disappeared completely within 48 h after ligation. After day 4, and especially on days 8 and 15 after ligation, the edges of the cardiomyocytes bordering the infarcted area manifested numerous sarcoplasmic tentacles that reacted positively to anti-desmin antibody. Distinct expression of Cx43 was observed extensively on the tentacles, although no cardiomyocytes remained viable around them. By day 60 after ligation, atypical expression of Cx43 had disappeared. These findings suggest that ischaemia induces temporally abnormal expression of Cx43, which might be responsible for abnormal conduction around the infarct. Received: 4 April 1997 / Accepted: 19 June 1997     

实验性病毒性心肌炎组织中连接蛋白43和结蛋白的表达

目的 了解病毒性心肌炎时心肌细胞连接蛋白４３和结蛋白表达情况,以探讨病毒性心肌炎时心律失常的机制。方法 应用免疫组织化学ＳＡＢＣ法,对实验性病毒性心肌炎小鼠心肌细胞连接蛋白４３和结蛋白的表达进行了观察。结果 连接蛋白４３和结蛋白在正常小鼠心肌闰盘中定位分布,均匀存在,后者还在肌节横纹中显示阳性;病毒性心肌炎时两者的表达明显减弱甚至阴性。结论 病毒性心肌炎时受累的心肌细胞连接蛋白４３和结蛋白的表达受     

Immunohistochemical analysis of connexin43 expression in infertile human testes

Connexin43 (Cx43) is abundantly expressed in mammalian testes and implicated in the regulation of cell-to-cell interaction between germ cells and Sertoli cells, which is essential to the normal process of spermatogenesis. In the present study, we investigated the relation between Cx43 expression and the degree of spermatogenesis in infertile human testes. Immunohistochemical analysis of Cx43 was performed on testicular biopsies from 29 patients with azoospermia (n=23) and severe oligospermia (n=6), who gave informed consent to this experiment. The degree of testicular spermatogenesis was evaluated by Johnsen score. In the interstitium, immunostaining for Cx43 was localized to some focal parts of plasma membrane between neighboring Leydig cells. In seminiferous tubules with normal spermatogenesis, Cx43 expression was found between Sertoli cells and germ cells. However, Cx43 expression in maturation arrest was decreased and located mainly in the basal compartment of seminiferous tubules. Finally, there was a significant positive correlation between histological score of spermatogenesis and intensity of Cx43 (p=0.0294). These data suggest that the alteration of Cx43 expression may be involved in spermatogenic impairment, and that the communication between Sertoli cells and germ cells through Cx43 may be important for maturation of spermatogenesis.