中国汉族人群腓骨肌萎缩症Cx32基因突变分析

Charcot Marie Tooth (CMT)diseaseisthemostcommoninheritedperipheralneuropathywithapreva lenceof 1in 2 5 0 0 .Distalmuscleweaknessandatro phy ,sensorylossandreducedorabsenttendonreflex es ,pescavus ,hammertoes ,steppagegaitareamongthemainsymptoms .Thereares…     

连接蛋白拟似肽对海人酸致痫大鼠脑电活动的影响

目的观察针对连接蛋白43(CX43)合成的特异性的缝隙连接阻断剂-连接蛋白拟似肽对海人酸致痫大鼠脑电活动的影响。方法建立18只大鼠癫痫动物模型,分连接蛋白拟似肽组、甘珀酸组和对照组(每组6只),在在体上分别局部给予连接蛋白似似肽、甘珀酸和生理盐水,用脑电图仪观测用药前后每组大鼠皮层脑电活动的变化情况。结果连接蛋白拟似肽组及甘珀酸组给药后癫痫的发作次数明显比给药前发作次数减少,癫痫波的平均振幅也明显变小,给药前后比较有显著性差异(P<0.01),生理盐水组给药前后癫痫的发作次数及平均振幅几乎没有变化。连接蛋白拟似肽组给药前后癫痫的发作次数和波幅的变化值与甘珀酸组给药前后癫痫的发作次数和波幅的变化值相比无显著性差异。结论针对CX43合成的连接蛋白拟似肽可以特异性地抑制癫痫的发作。     

oxLDL对人脐静脉内皮细胞通透性影响及机制研究

目的探讨氧化低密度脂蛋白（ox LDL）对人脐静脉内皮细胞（HUVECs）通透性的影响及其可能机制。方法采用Transwell单层细胞模型系统和油红O染色,观察ox LDL对单层血管内皮细胞通透性的影响以及THP-1巨噬细胞内脂质的蓄积情况;采用蛋白质印迹法及免疫荧光技术检测ox LDL对HUVECs紧密连接occludin蛋白的表达及分布改变。结果 ox LDL增加单层内皮细胞对LDL的通透性和THP-1巨噬细胞脂质的蓄积;ox LDL降低occludin蛋白的表达,同时免疫荧光染色显示,ox LDL处理后,血管内皮细胞间隙增宽,occludin染色减少或脱失,而抑制氧化应激可以减弱ox LDL对内皮细胞的高通透性反应和occludin蛋白表达和形态学的影响。结论 ox LDL可能是通过occludin蛋白表达下降使内皮细胞构改变来介导内皮通透性增加,从而促进内皮下巨噬细胞内的脂质蓄积。     

肺泡中性粒细胞凋亡与occludin蛋白改变在胆道梗阻大鼠肺损伤中的作用

目的：观察胆道梗阻（BDO）大鼠支气管肺泡灌洗液（BALF）中性粒细胞（PMN）凋亡情况与肺泡上皮细胞occludin蛋白变化,分析两者与梗阻性黄疸肺损伤的关系。 方法：72只SD大鼠,随机抽取8只作为正常对照组,将另64只大鼠随机均分为假手术组和模型组;假手术组大鼠行假手术,模型组大鼠行胆总管双重结扎建立BDO模型。假手术组与模型组大鼠于术后3、7、10、14 d分批等量（n=8）处死,留取标本;正常对照组则在实验期间随机处死获取标本。检测大鼠肺组织形态学、BALF中PMN凋亡率和MMP-9活性,肺组织occludin蛋白,并计算肺通透指数（LPI）。 结果：与正常对照组比较,假手术组各项指标在各时间点均无明显差异,定量指标间差异均无统计学意义（均P>0.05）。模型组肺组织出现明显的病理改变,且与假手术组比较,BALF中PMN凋亡率逐渐减少,MMP-9活性逐渐增高,3~14 d各时间点差异均有统计意义（均P<0.05）;肺组织occludin蛋白逐渐减少,LPI逐渐增加,在7~14 d各时间点差异均有统计意义（均P<0.05）。相关性分析显示,BDO大鼠PMN凋亡率与MMP-9活性呈负相关（r=-0.935）,MMP-9活性与肺组织occludin蛋白水平呈负相关（r=-0.796）,肺组织occludin蛋白水平与LPI呈负相关（r=-0.800）（均P<0.05）。 结论：BDO大鼠肺泡PMN凋亡减少、MMP-9活性增强,从而引起occludin蛋白减少,造成肺泡上皮屏障损伤、通透性增加,该病理过程在梗阻性黄疸肺损伤的发生发展中可能发挥了重要作用。     

链尿佐菌素诱导的糖尿病鼠视网膜N-钙蛋白的表达

目的 观察链脲佐菌素(STZ)诱导的糖尿病鼠视网膜N-钙粘蛋白(N-cadherin)的表达。 方法 20只Sprague Dawley(SD)大鼠腹腔一次性注射65 mg/kg STZ建立糖尿病模型，另20只SD大鼠腹腔一次性注射等体积枸橼酸盐缓冲液作为对照。伊文思蓝检测视大鼠网膜血管的渗透性；免疫组织化学、Western blotting方法检测对照组及糖尿病组大鼠视网膜及用胰蛋白酶消化的视网膜微血管N-钙粘蛋白表达情况。 结果糖尿病诱导4、8、12 周后视网膜血管渗透性分别增加68%、91%、125%(P<0.005)。对照组视网膜N-钙粘蛋白主要表达在视网膜外网状层、内网状层、内核层、神经节细胞层、内界膜及视网膜微血管内皮细胞和周细胞之间。STZ诱导糖尿病鼠12周后视网膜及视网膜微血管N-钙粘蛋白表达显著下降。Western blotting分析结果显示随着糖尿病视网膜病变的发展，视网膜N-钙粘蛋白表达显著减少。 结论 STZ诱导的糖尿病大鼠视网膜N-钙粘蛋白的表达降低，提示反应性N-钙粘蛋白可能参与早期糖尿病视网膜病变的发生。(中华眼底病杂志,2007,23:269-272)      

Expression and function of astrocytic gap junctions in aging

Astrocytic gap junctions have been implicated in a variety of signaling pathways essential to normal brain function. However, no information exists on the prevalence of gap junction channels and their function in the aging brain. Here we have compared the expression of the two most abundant astrocytic gap junction proteins in young and senescent brains and quantified the extent of functional gap junction coupling. The expression level of Cx43 peaked in 7-month-old mice. The relative numbers of Cx43 immunoreactive plaques were 596+/-61, 734+/-62, and 755+/-114 in 3-, 7-, and 21-month-old mice, whereas plaques size averaged 0.9+/-0.1 microm(2) (3 months), 1.3+/-0.1 microm(2) (7 months), and 0.7+/-0.1 microm(2) (21 months). The expression level of Cx30 was also highest in 7-month-old animals (315+/-49 plaques, size 0.8+/-0.07 microm(2) vs. 585+/-51 plaques, size 0.9+/-0.1 microm(2) in 3- and 7-month-old mice, respectively), but only 262+/-63 plaques (size 0.4+/-0.04 microm(2)) in 21-month-old mice. Western blot analysis revealed that the content of both Cx43 and Cx30 remained relatively constant at 3, 7, and 21 months. The fluorescence recovery of photobleach technique (FRAP) was used to evaluate coupling in freshly prepared hippocampal slices. Gap junction coupling did not change significantly as a function of aging, but a tendency towards reduced coupling was observed as the animals aged. Average fluorescence recovery after 2 min was 63+/-6% in younger animals, 59+/-5% in adult animals, and 54+/-4% in old brain. These observations indicate that although astrocytic gap junction proteins are maintained at high levels through the entire lifespan of mice, aging is associated with changes in the number and size of both Cx30 and Cx43 gap junction plaques.     

心房肌间隙连接重构与风湿性瓣膜病患者心房颤动的关系

目的　探讨风湿性瓣膜病慢性心房颤动 (房颤 )患者心房肌组织中连接蛋白 4 0 (Cx4 0 )和连接蛋白 4 3(Cx4 3)蛋白质表达和分布的变化与慢性房颤的关系。方法　 32例风湿性心脏病患者 ,其中慢性房颤患者 2 1例 ,窦性心律者 11例 ,瓣膜置换术时取右心耳组织。用免疫荧光双标共聚焦显微镜和Western印迹观察Cx4 0和Cx4 3蛋白质表达和分布的改变。结果　激光共聚焦显微镜计算的Cx4 0荧光斑面积反映了蛋白表达水平 ,慢性房颤组为 0 6 7μm2 / μm3 ± 0 0 9μm2 / μm3 ,显著低于窦性心律组的 1 4 5 μm2 / μm3 ± 0 16 μm2 / μm3 (P <0 0 1) ,且细胞端端连接减少较侧侧连接处严重 ,分布呈现不均一性。Cx4 3总体表达水平未变 ,慢性房颤组为 1 38μm2 / μm3 ± 0 14 μm2 / μm3 ,窦性心律组为 1 5 3μm2 / μm3 ± 0 2 7μm2 / μm3 ,但侧侧分布增加而横向分布减少。Western印迹反映的Cx4 0和Cx4 3蛋白质表达水平与激光共聚焦观察结果一致。结论　心房肌Cx4 0和Cx4 3蛋白质水平降低和再分布可能与风湿性瓣膜病慢性房颤的发生和维持有关。     

Molecular mechanisms of TPA-mediated inhibition of gap-junctional intercellular communication: evidence for action on the assembly or function but not the expression of connexin 43 in rat liver epithelial cells.

We found that a rat liver epithelial cell line (IAR 20) expresses connexin 43, the major cardiac gap-junction protein, but not connexin 26 or connexin 32, major liver gap-junction proteins. The effects of TPA on connexin 43 expression in IAR 20 were investigated using northern blot analysis, western blot analysis, and an immunofluorescence technique. Gap-junctional intercellular communication (GJIC) in this cell line decreased within 60 min of 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment and recovered after 24 h. The number of immunofluorescence spots of connexin 43 on IAR 20 was closely related to the change in GJIC induced by TPA. However, TPA did not change the level of mRNA measured by northern blot analysis. Moreover, connexin 43 protein expression analyzed by western blotting suggests that connexin 43 proteins were still present in TPA-treated cells at a similar level. These results suggest that GJIC of these rat liver epithelial cells was mediated by connexin 43 protein and that TPA inhibited GJIC by inhibiting posttranslational processing of connexin 43 proteins, e.g., localization or assembly.