THE EFFECT OF ALL-TRANS RETINOIC ACID ON GAP JUNCTIONAL INTERCELLULARCOMMUNICATION AND CONNEXIN 43 GENE EXPRESSION IN GLIOMA CELLS

To illuminate the regulating effect of all trans retinoic acid (ATRA ) on gap junctional intercellular communication (GJIC) and connexin 43 (Cx43) ge ne expression in glioma cells, which is tissue and organ specific. Method. Rat C6 glioma cells were exposed to ATRA at a concentration of 1, 10, 10 0 μmol/L respectively, and the GJIC function of the cells was examined with scr ape loading dye transfer assay 24 hours, 48 hours and 72 hours after ATRA treat ment. The effect of ATRA on Cx43 gene expression was measured with semiquantitat ive reverse transcription polymerase chain reaction (RT PCR) 24 hours after ATR A exposure. Results. The GJIC function of C6 glioma cells was significantly increased by ATR A at each concentration applied. The dye passed 4 to 5 rows of cells from the sc raping edge in ATRA treated cells, but only 1 or 2 rows in the control. The augm ent effect was observed 24 hours after each concentration ATRA treatment, and la sted till 72 hours after treatment with 1μmol/L and 10μmol/L ATRA. Forty eigh t hours after exposed to 100μmol/L ATRA, the enhancement of GJIC was less obvi ous. There was no significant increase induced by ATRA on the transcription of C x43 gene, as demonstrated by semiquantitative RT PCR. Conclusion. ATRA turned out to be a potent enhancer on GJIC function in C6 gliom a cells, and the enhancement effect was most probable at post transcriptional l evel.

Altered Expression of Connexin-43 and Impaired Capacity of Gap Junctional Intercellular Communication in Prostate Cancer Cells

Connexin-43 (Cx43) expression in prostate cancer (PCa) cells and the potency of gap junctional intercellular communication (GJIC) in the cells were investigated, with an attempt to elu- cidate the reason why the so-called 'bystander effect' mediated by thymidine kinase (TK) suicide gene therapy on PCa cells is not of significance and to explore the role of GJIC in PCa carcinogenesis. mRNA and protein expression of Cx43 in a PCa cell line PC-3m was detected by re- verse-transcription polymerase chain reaction (RT-PCR) and strapt-avidin-biotin-enzyme complex (SABC) immunohistochemical staining, and inherent GJIC of PC-3m cells was assayed by scrape-loading and dye transfer (SLDT) assay. The expression of Cx43 in human normal and malig- nant prostate tissues was determined by SABC immunohistochemistry as well. It was found that Cx43 mRNA and protein expression in PC-3m cells was slightly reduced as compared with positive controls and the location of Cx43 protein was aberrant in cytoplasm rather than on membrane. As- sessment of paraffin sections demonstrated that the expression of Cx43 protein in PCa cells was ab- normally located and markedly diminished as compared with normal prostatic epithelial ones, dis- playing a negative correlation to the pathological grade (χ2=4.025, P<0.05). Additionally, capacity of inherent GJIC in PC-3m cells was disrupted, which was semi-quantified as (+) or (-). It was indi- cated that both down-regulated expression of Cx43 mRNA and aberrant location of Cx43 protein par- ticipated in the mechanisms leading to deficient GJIC in PC-3m cells. Lack of efficient GJIC is a molecular event, which may contribute not only to limited extent of 'bystander effect', but also to initiation and progression of prostatic neoplasm.

STUDIES ON THE GAP JUNCTIONAL INTERCELLULARCOMMUNICATION OF HUMAN NASOPHARYNGEALCARCINOMA CELLS AND THE EFFECT OF RII

Human nasopharyngeal carcinoma(NPC) cell line,CNE-2Z, and its clones(L2, H2, L4) with various invasive and metastatic potentials were examined for their gap junctions(GJ), gap junctional intercellular communication(GJIC) and the concentration of cytosolic free calcium(Ca2+). Only a few intermediate junction(IJ)but no GJ structures were observed under electron microscope(EM). CNE-2Z cells showed marked JGIC,while its variants lacked this function using the scraploading dye-transfer technique(SLDT). There was lower concentration of[Ca2+]. in L2 cells(a variant with high invasive and metastatic Potential) compared to that in H2 and L4 cells(variants with medium and low invasive and metastatic Potentials, respectively). These data suggested that high invasive and metastatic potentials might be correlated with the levcl of[Ca2+]i in NPC cells.The effect of RII(4-hydroxycarbophenyl retinamide) on NPC cells also investigated, After 3-7 d of RII(10-5 M) treatment, there was no change in the number of gap junctions and other kind of intercellular junctions in NPC cells observed under EM. The JGIC of CNE-2Z weaked and then disappeared finally with prolonging of RII treatment. However. there was no influence on its variants. The level of[Ca2+], in NPC cells apparently fell after 6 h of RII treatment, and rose to original level with persisting of RII treatment. Whether the fluctuating of[Ca2+]i level is related to the inhibitory effect of RII treatment on growth and invasion of NPC cells needs to be further studied.

Mechanism of changes in gap junctional intercellular communication in myocardial cells after burns

Objective: To explore the pathophysiological mechanism of the changes in gap junctionalintercellular communication (GJIC) in the myocardial cells after burns. Methods: After the myocardial cellswere cultured and injured with hypoxia and burn serum, the GJIC in the cells was detected with scrapeloading and dye transfer. Meanwhile, the viability, cytosolic free Ca2+ concentration and Ca2+ influx of themyocardial cells were determined. Results: The cytosolic free Ca2+ concentration and the cellulartransmembrane Ca2+ influx were significantly increased but the viability of the cells markedly decreased afterthe injury. The LY fluorescence reached 4 rows of cells from the scrape line in the normal myocardial cells.The GJIC was blocked at the first hour after hypoxia or hypoxia and burn serum injury. The LY fluorescencewas limited to the primary loads cells at the sixth hour after hypoxia and the third hour after hypoxia andburn serum injury. Conclusion: The function of GJIC in the myocardial cells is to maintain high ordersynchronous contraction of the myocardium. After burns, the runaway calcium homeostasis and impairmentof GJIC function would be accused to be the pathological basis for myocardial heterogeneous behavior.

Changes of gap junctional intercellular communication in detrusor instability

Objective: To demonstrate the functional changes of gap junctional mediation of intercellular communication in detrusor instability (DI) and its mechanisms. Methods: The function of gap junctional intercellular communication in the cultured bladder detrusor cells was detected by fluorescence redistribution after photobleaching. Results: At the fourth minute after bleaching, the mean fluorescences recovery rates of DI group bladder detrusor cells were (35 791±0 836)%, that of control group (8 645±0 673)%. The mean fluorescence recovery rates of DI group were significantly higher than those of control group ( P <0 01). Conclusion: It shows that the increase of intercellular excitatory communication is one of the important reasons of pathogenesis of DI.

Up-Regulation of the Gap Junction Intercellular Communication by Tea Polyphenol in the Human Metastatie Lung Carcinoma Cell Line

Our previous study has proven that tea polyphenol has a role in lung neoplasms. The present communication was to investage the anti-proliferation effect of tea polyphenol on the PG cells, which was a high metastatic human lung carcinoma cell line, by 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-diphenytetrazoliumromide (MTT) cell viability assay, and to study the change of intracellular calcium concentration, connexin43 (Cx43) expression, gap junctional intercellular communication (GJIC) and cell cycle distribution after the tea polyphenol treatment by laser scanning confocal microscopy and flow cytometry. The results showed that 1) tea polyphenol could kill the PG cells in a dose-depent manner via inhibiting the PG cell proliferation and blocking the PG cell cycle progression staying in G0/G1 phase and not transfering in S and G2/M phases to reduce the PG cell proliferation index;2) the increases of intracellular calcium concentration, GJIC and Cx43 expression were related with the tea polyphenol doses. The data suggested that tea polyphenol could inhibit the growth of PG cells, which mechanism was associated with the up-regulation of GJIC.

EFFECTS OF LIMONENE,SALVIA MILTIORRHIZA AND TURMERIC DERIVATIVES ON H-RAS ONCOGENE EXPRESSION AND GAP JUNCTION INTERCELLULAR COMMUNICATION IN HUMAN SOLID TUMOR CELL LINES

Objective: To study gap junction intercellular communication (GJIC), H ras oncogene expression and ras oncogene product (P 21 ras protein) expression in four human solid tumor cell lines, W1-38,CACO 2,A549 and PaCa, and the effects of four compounds, Salvia miltiorrhiza derivative (SMD), d Limonene, Turmeric derivative I (TD I) and Turmeric derivative II (TD II), on them. Methods: The abilities of the four solid tumor cell lines to transfer dye to adjacent cells were examined by the scrape loading/dye transfer technique, and the H ras oncogene expression by Northern blotting and P 21 ras protein expression by Western blotting. Results: The results showed the loss of intercellular coupling in PaCa cells, slight GJIC in A549 and CACO 2 cells, and a good GJIC in W1-38 cells. The four compounds could improve the GJIC of PaCa to different extents. The amount of total and membrane associated P 21 ras in PaCa cells were decreased after treatment with SMD, d Limonene and TD I (2.5 μg/ml) for 48 h. Concomitantly, the growth of PaCa cells decreased in soft agar and had enhanced GJIC. The relative potency was found to be:d Limonene>SMD >TD I=TD II. There was no significant effect of the four compounds on H ras oncogene expression. Conclusion: It was suggested that there was an excellent correlation between loss of Lucifer Yellow dye transfer and ras gene mutation rate in the four solid tumor cell lines (ras gene mutation rate inversely correlated with average cell number coupled, r=0.98) i.e., the high ras gene mutation was closely correlated with loss of GJIC in these malignant human tumor cells; The antitumor effect of the monoterpene d Limonene and the phenol compound, SMD, might be related to inhibition of P 21 ras membrane association and enhancement of GJIC, whilst that of the others may be by a different mechanism; The inhibition of P 21 ras membrane association was directly related to the enhancement of gap junction intercellular com munication.

Intercellular communication of notochord cells during their differentiation in Cynops orientalis

Intercellular communication of notochord cells during their differentiation was studied by microinjection of a fluorescent dye, Lucifer Yellow. Close correlation existed between the incidences of dye coupling and quantitative evaluation of gap junctions. High incidences of dye coupling and of gap junctions occurred at a stage when notochord cells were active in the change of cell shape and cell arrangement. With the subsidence of cell movements, both dye coupling and gap junctions were reduced to lower levels. It was, therefore, suggested that intercellular communication via gap junctions played an important role in the coordination of notochord cell movements.Gap junctions of altered configuration occurred in notochord cells in late tailbud stage. The comparison of incidences of dye coupling at this stage with those at other stages strongly suggested that the gap junctions of altered configuration functioned just as those of generalized type.

Connexin 43-modified bone marrow stromal cells reverse the imatinib resistance of K562 cells via Ca^(2+)-dependent gap junction intercellular communication

Background: Imatinib mesylate (IM) resistance is an emerging problem for chronic myeloid leukemia (CML). Previous studies found that connexin 43 (Cx43) deficiency in the hematopoietic microenvironment (HM) protects minimal residual disease (MRD), but the mechanism remains unknown. Methods: Immunohistochemistry assays were employed to compare the expression of Cx43 and hypoxia-inducible factor 1α (HIF-1α) in bone marrow (BM) biopsies of CML patients and healthy donors. A coculture system of K562 cells and several Cx43-modified bone marrow stromal cells (BMSCs) was established under IM treatment. Proliferation, cell cycle, apoptosis, and other indicators of K562 cells in different groups were detected to investigate the function and possible mechanism of Cx43. We assessed the Ca^(2+)-related pathway by Western blotting. Tumor-bearing models were also established to validate the causal role of Cx43 in reversing IM resistance. Results: Low levels of Cx43 in BMs were observed in CML patients, and Cx43 expression was negatively correlated with HIF-1α. We also observed that K562 cells cocultured with BMSCs transfected with adenovirus-short hairpin RNA of Cx43 (BMSCs-shCx43) had a lower apoptosis rate and that their cell cycle was blocked in G0/G1 phase, while the result was the opposite in the Cx43-overexpression setting. Cx43 mediates gap junction intercellular communication (GJIC) through direct contact, and Ca ^(2+ )is the key factor mediating the downstream apoptotic pathway. In animal experiments, mice bearing K562, and BMSCs-Cx43 had the smallest tumor volume and spleen, which was consistent with the in vitro experiments. Conclusions: Cx43 deficiency exists in CML patients, promoting the generation of MRD and inducing drug resistance. Enhancing Cx43 expression and GJIC function in the HM may be a novel strategy to reverse drug resistance and promote IM efficacy.

Cisplatin-induced premature senescence with concomitant reduction of gap junctions in human fibroblasts

To examine the role of gap junctions in cell senescence,the changes of gap junctions in cisplatin-induced premature senescence of primary cultured fibroblasts were studied and compared with the replicative senescent human fibroblasts.Dye transfer assay for gap junction function and immunofluorescent staining for connexin 43 protein distribution were done respectively. Furthermore,cytofluorimetry and DAPI fluorescence staining were performed for cell cycle and apoptosis analysis. p53 gene expression level was detected with indirect immunofluorescence. We found that cisplatin (10 mM) treatment could block cell growth cycle at G1 and induced premature senescence. The premature senescence changes included high frequency of apoptosis,elevation of p53 expression,loss of membranous gap junctions and reduction of dye-transfer capacity. These changes were comparable to the changes of replicative senescence of human fibroblasts. It was also concluded that cisplatin could induce premature senescence concomitant with inhibition of gap junctions in the fibroblasts. Loss of functional gap junctions from the cell membrane may account for the reduced intercellular communication in the premature senescent fibroblasts. The cell system we used may provide a model useful for the study of the gap junction thus promoting agents against premature senescence.

Basic Investigations EXPRESSION OF GAP JUNCTION PROTEIN Cx43 IN CULTURED HUMAN NORMAL AND MALIGNANT LUNG CELLS

Gap junctional intercellular communicationexchange of small molecules and ions between contiguous cells through membranous gap junctional channelsis essential for growth control and tissue homecotasis. This work concerns the functional expression of gap junction protein connexin 43 (Cx43) in normal human lung cells and the changes in lung carcinoma cells. By. using Northern blot hybridization analysis and Cx43 immunocytochemical methods, it was otherved that cultured normal human embryonic lung cells expressed a high level of Cx43 in both mRNA and protein levels.The Cx43 immunofluorescence was localized at cell membrane regions corresponding to the location of gap junctions. These normal lung cells were competent of intercellular communication function as detected by Lucifer yellow dye transfer. In contrast to normal celis, Cx43 mRNA and protein was not detectable in the carcinoma PG cell line. These tumor cells were defective of intercellular communication function. These results demonstrate that Cx43 is expressed in normal cultured human embryonic lung cells but not in lung tumor cells. The lack of intercellular communication in the lung tumor cell line correlates with dysfunctional intercellular communication. The suggestive role of Cx as a tumor suppersor gene is discussed.

六味地黄丸通过干预缝隙连接通讯功能调控树突状细胞抗原交叉提呈能力研究

【目的】探讨六味地黄丸是否通过提高缝隙连接通讯功能(GJIC)增强树突状细胞(DC)抗原交叉提呈能力,并对其机制进行相关探索。【方法】采用Western Blot实验、免疫荧光法观察六味地黄丸含药血清对黑色素瘤细胞(B16)缝隙连接蛋白43(Cx43)表达及膜定位的影响;采用钙黄绿素(Ca-AM)/DiI荧光示踪实验观察六味地黄丸含药血清对B16细胞GJIC功能的影响;采用流式细胞术观察GJIC在六味地黄丸含药血清增强DC抗原提呈能力中的作用;采用碘化丙啶(PI)/Hoechst染色实验观察CD8+T淋巴细胞的免疫杀伤效果。【结果】Western Blot及免疫荧光实验结果显示,六味地黄丸含药血清上调Cx43表达;荧光示踪实验证明,六味地黄丸含药血清显著增强B16细胞GJIC功能;流式细胞术分析表明,六味地黄丸含药血清增强DC抗原提呈能力;PI/Hoechst染色结果显示,六味地黄丸含药血清干预B16-OVA后CD8+T细胞的免疫杀伤效果更加显著。【结论】六味地黄丸通过上调黑色素瘤细胞Cx43表达,改善GJIC功能,进而增强DC的交叉提呈能力,从而激活更强的CD8+T细胞免疫杀伤反应。

EMs异位及在位内膜间质细胞Cx43的表达及GJIC功能的体外研究

目的:研究子宫内膜异位症(EMs)的异位与在位内膜间质细胞中Cx43的表达及间隙连接细胞间通讯(GJIC)功能,探讨间质细胞GJIC功能异常对EMs发病的影响。方法:取24例卵巢处子宫内膜异位灶、41例EMs在位内膜以及30例正常子宫内膜,分离出间质细胞,加入雌、孕激素培养,建立体外间质细胞培养模型。利用激光共聚焦显微镜(LSCM)分别检测三组间质细胞的Cx43表达及GJIC功能。结果:间质细胞成功培养率分别为:异位内膜组45.8%(11/24)、EMs在位内膜组92.7%(38/41)、对照组93.3%(28/30),异位内膜间质细胞纯度为95%,在位内膜间质细胞纯度达98%。EMs异位内膜间质细胞中Cx43表达水平及GJIC功能明显比其他两组低,正常对照组的Cx43表达水平及GJIC功能最高,且差异均有显著性(P﹤0.01)。结论:(1)同时建立EMs异位内膜、在位内膜及正常内膜间质细胞的体外模型,有助于研究EMs的发病机制;(2)间质细胞中Cx43蛋白表达下调及其GJIC功能异常与EMs发生有关,调节Cx43表达或GJIC功能可能是潜在的治疗策略。

ATRA调节人异位子宫内膜间质细胞GJIC Connexin基因、蛋白的作用及意义

目的:探讨全反式维甲酸(ATRA)对人异位子宫内膜间质细胞间隙连接细胞间通讯(GJIC)、connexin基因、蛋白的调节作用及意义。方法:取24例子宫内膜异位症患者卵巢处异位内膜标本,分离纯化得到间质细胞,分别用0.1mmol/L、1mmol/L、10mmol/LATRA处理24h、48h、72h、96h、120h,同时设置空白对照组,采用荧光漂白后恢复技术检测异位内膜间质细胞的GJIC功能,并检测与GJIC功能密切相关的Cx43、Cx26、Cx32的基因及蛋白表达。结果:ATRA处理72h内,1mmol/L、10mmol/L组的异位内膜间质细胞荧光恢复功能明显增强;0.1mmol/LATRA组的异位内膜间质细胞荧光恢复功能无明显变化。未经ATRA处理的异位内膜间质细胞中无Cx43、Cx26、Cx32的mRNA及蛋白表达;经1mmol/LATRA处理后,异位内膜间质细胞中检测到Cx43mRNA和蛋白表达,但未见Cx26、Cx32的mRNA及蛋白表达。结论:ATRA能选择性地诱导Cx43基因及蛋白表达,从而有效上调异位内膜间质细胞的GJIC功能;ATRA可能是治疗子宫内膜异位症的潜在药物。

黄芩素对缝隙连接蛋白Cx32组成的GJIC功能的影响

目的:在转染并稳定表达Cx32的HeLa细胞上,观察黄芩素对Cx32组成的GJIC及Cx32蛋白表达水平的影响。方法:细胞接种荧光示踪法观察不同浓度黄芩素对GJIC的影响;细胞免疫荧光法观察黄芩素在影响GJIC功能浓度范围内对Cx32蛋白表达的影响。结果:黄芩素(2.5μmol/L,5μmol/L,10μmol/L)增强Cx32组成的GJIC功能的荧光渗透率为10.04%,22.5%和35.33%;黄芩素(2.5μmol/L,5μmol/L,10μmol/L)增强组成GJIC的Cx32蛋白表达的荧光强度为(27.12±0.30)%,(56.31±1.02)%和(83.47±1.85)%。结论:黄芩素可增强缝隙连接蛋白Cx32组成的GJIC功能,其机制可能与增加Cx32蛋白表达水平有关。

胆汁酸的遗传毒性和对细胞间隙连接通讯(GJIC)抑制作用的研究

本文应用Ａｍｅｓ试验，ＣＨＬ细胞体外染色体畸变试验检测了脱氧胆酸和石胆酸的遗传毒性；还观察了脱氧胆酸和石胆酸对ＮＩＨ／３Ｔ３细胞的恶性转化作用。并应用划痕标记染料示踪技术（ＳＬＤＴ）观察了胆汁酸对细胞间隙连接通讯（ＧＪＩＣ）的抑制作用。结果表明，脱氧胆酸和石胆酸无诱发基因突变和染色体畸变作用，也无诱发培养细胞的恶性转化作用。因此本实验未证明脱氧胆酸和石胆酸是遗传毒性致癌物。然而，脱氧胆酸和石胆酸对ＮＩＨ／３Ｔ３细胞ＧＪＩＣ均有明显抑制作用。

Connexin 40-formed GJIC increases the phototoxicity of photodynamic therapy through ROS-and calcium-mediated pathways

OBJECTIVE To explore the effect of connexin(Cx)40-formed gap junctional intercellular communication(GJIC)on Photofrin-photodynamic therapy(PDT)phototoxicity in Cx40-transfected He La cells and its potential mechanisms.METHODS He La cell line stably transfected to express Cx40 was seeded at high and low cell density,respectively,to assess in vitro photosensitivity using CCK8 assay.Western blot assay was performed to detect the expression of Cx40.The intracellular ROS and Ca^(2+) concentrations were determined using flow cytometer.4-HNE and ceramide were measured using ELISA assay.RESULTS Cx40-composed GJ formation at high density enhances the phototoxicity of PhotofrinPDT.When the Cx40 is not expressed or Cx40 channels are blocked,the phototoxicity in high-density cultures substantially reduces,indicating that the enhanced PDT phototoxicity at high density is mediated by Cx40-composed GJIC.The GJIC-mediated increase in PDT phototoxicity was associated with ROS and calcium-mediated stress signaling pathways.CONCLUSION The work uniquely presents the ability of Cx40-composed GJIC to enhance the sensitivity of malignant cells to PDT,and indicates that maintenance or increase of Cx40-formed GJIC may be a profitable strategy towards the enhancement of PDT therapeutic efficiency.

洛伐他汀对MCF-7细胞增殖分化功能及间隙连接细胞通讯的影响

背景与目的:洛伐他汀(lovastatin)是细胞内源性胆固醇合成的抑制剂,临床已普遍用于治疗高脂血症。现有研究报道,洛伐他汀具有抗肿瘤作用,但分子机制尚不清楚。本文探讨洛伐他汀对人乳腺癌细胞MCF-7增殖功能以及间隙连接细胞通讯(gapjunctionalintercellularcommunication,GJIC)的影响。方法:分别以4、8、16μmol/L洛伐他汀处理MCF-7细胞24～72h后,流式细胞仪检测细胞周期的时相分布及细胞凋亡率,硝基蓝四氮唑(NBT)还原实验鉴定细胞分化,并采用划痕标记染料示踪技术观察洛伐他汀对MCF-7细胞GJIC功能的影响。结果:不同浓度洛伐他汀处理细胞不同时间后,MCF-7细胞的增殖明显受抑,抑制率最高可达75.8%,且同一处理时相点各组间比较差异均有显著性(P<0.05);细胞周期分析显示,各处理组内G0/G1期细胞明显增多,处理72h后可高达80%左右;同时洛伐他汀能明显促进MCF-7细胞分化、各处理组间比较差异均有显著性(P<0.01),但洛伐他汀诱导该细胞凋亡的作用不明显。另外,洛伐他汀有上调或恢复MCF-7细胞GJIC的作用;16μmol/L洛伐他汀处理细胞72h后,荧光染料传输的范围可达4～5层细胞。以上作用均有浓度-效应和时间依赖关系。结论:洛伐他汀可抑制MCF-7细胞增殖,使细胞生长阻滞于G0/G1期,并能促进细胞分化,该作用可能与洛伐他?

北京市大气细颗粒物的遗传和非遗传毒性研究

用胞质阻断微核试验与单细胞凝胶电泳法检测北京市大气PM2.5无机提取物与有机提取物对Balb/c 3T3细胞微核形成与DNA链断裂的影响;通过划痕染料示踪技术(SL/DT)观察PM2.5无机提取物与有机提取物对Balb/c3T3细胞间通讯的影响.发现PM2.5有机提取物可引起双核微核细胞率显著增加(P<0.01)及导致慧星细胞率和DNA迁移长度显著增加(P<0.01);PM2.5有机提取物引起细胞间通讯的抑制; PM2.5无机提取物未见明显毒作用.结果表明,PM2.5可引起染色体损伤和原发性DNA损伤,抑制细胞间通讯,其毒作用主要由其有机成分引起.

北京市大气PM_(10)和PM_(2．5)对人肺成纤维细胞间隙连接通讯及连接蛋白的影响

[目的]探讨北京市大气颗粒物PM_(10)和PM_(2.5)对人肺成纤维细胞(HLF)间隙连接通讯(GJIC)及间隙连接蛋白(Cx43)的影响。[方法]颗粒物样品采自北京市城区采暖期,实验细胞为HLF。采用划痕染料标记示踪法(SLDT)测定HLF的GJIC的水平;蛋白免疫印迹(weslen bloting)法观察HLF细胞膜上Cx43的表达。[结果]细胞划痕实验结果显示,PM_(10)和PM_(2.5)均可抑制细胞间荧光扩散,抑制作用随剂量增高而增强;蛋白免疫印迹结果显示,PM_(10)和PM_(2.5)可使细胞膜Cx43表达减少,减少量随浓度的增高而增加。[结论]北京市大气颗粒物PM_(10)和PM_(2.5)能抑制HLF的GJIC,抑制的机制可能与Cx43表达抑制有关。