Object The polysaccharide (CDPS) was isolated, purified and identified from Cistanche deserticola Y. C. Ma, a Chinese materia medica. Methods The polysaccharide was extracted with hot water and precipitated by alcohol. Protein in the precipitates was removed by Sevag method. The products were further purified with column chromatography on DEAE-Sephadex A-50 and Sephacryl S-200. The CDPS was idendified by IR spectrum and UV (200-400 nm) scanning spectrum. Results IR spectrum indicates that there are typical characteristic absorption peaks of polysaccharides. UV scanning spectrum shows that there are no absorption peaks of protein and nucleic acid at point 280 nm and 260 nm. Conclusion The CDPS was identified as homogeneous one.

Objective　To explore the relationships betw een pulmonary fibrosis and downregulation of gap junctional intercellular comm unication(GJIC) of the fibroblasts after stimulation by SiO2. Metho ds　The pulmonary alveolar macrophage(PAM) and the phorbol 12-myrist ate 13-acetate(PMA or TPA) primed THP-1(pTHP-1),a monocyte-like cell line wi th the properties of PAM,were incubated in the serum-free RPMI?1640 containing SiO2 at various concentrations.The proliferation of Chinese hamster lung(CHL) fibroblast induced by cultured PAM or pTHP supernatant was detected by using MT T assay(to show as the a bsorbency,A570 nm),and GJIC between those cells was measured by using the fluorescence redis tribution after photobleaching(FRAP) assay(to show as the transfer rate of the f luorescence,K×10-3/s) performed with a laser scanning confocal micr oscope(LSCM,Carl Zeiss LSM 510,release 2.01). Results　Bot h SiO2 exposed PAM and pTHP-1 supern atants could induce the proliferation(PAM:F=3.205,P<0.05;pTHP-1:F=1 3.779,P<0.01) and the downregulation of GJIC(PAM:F=19.948,P<0. 01;pTHP-1:F=9.365,P<0.01) of the CHL cells.In the range of 0,50,1 00,200 and 500 μg/ml SiO2 concentrations,the proliferation(A570 nm values) and GJIC(the transfer rate,K)were fitted well in the dose-effect re lationship(PAM:r=-0.803,P<0.05;pTHP-1：r=-0.914,P<0.01). Compared with the blank control,both PAM and pTHP-1 supernatants could upregu late GJIC(K:21.24×10-3/s,18.92×10-3/s vs. 7.81×10 -3/s,7.81×10-3/s respectively,P<0.05) and inh ibit the proliferation of CHL cell(A570 nm:0.506,0.218 vs. 0.5 39,0.388 respectively,P<0.05). Conclusion　T hrough the way of stimulating PAM,SiO2 could inhibit GJIC of fibroblasts,and induce fibroblast proliferation.In the pathoge nesis of silicotic fibrosis,the downregulation of GJIC of the pulmonary fibrobla sts may play an important role.

Objective　To explore the relationships betw een pulmonary fibrosis and downregulation of gap junctional intercellular comm unication(GJIC) of the fibroblasts after stimulation by SiO2. Metho ds　The pulmonary alveolar macrophage(PAM) and the phorbol 12-myrist ate 13-acetate(PMA or TPA) primed THP-1(pTHP-1),a monocyte-like cell line wi th the properties of PAM,were incubated in the serum-free RPMI?1640 containing SiO2 at various concentrations.The proliferation of Chinese hamster lung(CHL) fibroblast induced by cultured PAM or pTHP supernatant was detected by using MT T assay(to show as the a bsorbency,A570 nm),and GJIC between those cells was measured by using the fluorescence redis tribution after photobleaching(FRAP) assay(to show as the transfer rate of the f luorescence,K×10-3/s) performed with a laser scanning confocal micr oscope(LSCM,Carl Zeiss LSM 510,release 2.01). Results　Bot h SiO2 exposed PAM and pTHP-1 supern atants could induce the proliferation(PAM:F=3.205,P<0.05;pTHP-1:F=1 3.779,P<0.01) and the downregulation of GJIC(PAM:F=19.948,P<0. 01;pTHP-1:F=9.365,P<0.01) of the CHL cells.In the range of 0,50,1 00,200 and 500 μg/ml SiO2 concentrations,the proliferation(A570 nm values) and GJIC(the transfer rate,K)were fitted well in the dose-effect re lationship(PAM:r=-0.803,P<0.05;pTHP-1：r=-0.914,P<0.01). Compared with the blank control,both PAM and pTHP-1 supernatants could upregu late GJIC(K:21.24×10-3/s,18.92×10-3/s vs. 7.81×10 -3/s,7.81×10-3/s respectively,P<0.05) and inh ibit the proliferation of CHL cell(A570 nm:0.506,0.218 vs. 0.5 39,0.388 respectively,P<0.05). Conclusion　T hrough the way of stimulating PAM,SiO2 could inhibit GJIC of fibroblasts,and induce fibroblast proliferation.In the pathoge nesis of silicotic fibrosis,the downregulation of GJIC of the pulmonary fibrobla sts may play an important role.

OBJECTIVETo study the effect of supernatants from silicon dioxide(SiO2) stimulated pulmonary alveolar macrophages(PAM) on the localization of connexin 43(Cx43) so as to explore the inhibition level of SiO2 on alveolar epithelial cellular gap-junctional communication(GJIC).

METHODSThe supermatants from the primary cultured PAM were prepared, and then added 5% (v/v) SiO2 into 2% (v/v) NBS RPMI 1640 to stimulate the normal mink lung epithelial cell line CCL-64 for 24 hours. The localizations of Cx43 in CCL-64 were analyzed by indirect immunofluorescence histochemistry and laser confocal scanning microscopy(LCSM).

RESULTSThe normal cultured CCL-64 cells displayed bright membrane-associated Cx43 plaques labeling and formed dashes at regions of intercellular junction. Being exposed to supernatants from SiO2-stimulated PAM, the CCL-64 cells retained a relative low degree of Cx43 labeling at the cell periphery, localized in cytoplasm, and the individual spot, rather than plaques, were smaller compared to normal cultured cells. Along with the increase of the concentrations of SiO2, the cells displayed a different staining pattern, with clear cluster labeling aggregating towards the nucleus.

CONCLUSIONThe altered localization of the gap-junctional protein Cx43 in alveolar epithelial cells, mediated by SiO2, indicated that the internalization of Cx43 may contribute to the inhibition on GJIC in silica-induced lung epithelium injury.

Animals ; Cell Communication ; drug effects ; Cell Line ; Connexin 43 ; analysis ; Epithelial Cells ; chemistry ; drug effects ; Fluorescent Antibody Technique, Indirect ; Gap Junctions ; drug effects ; Microscopy, Confocal ; Mink ; Pulmonary Alveoli ; chemistry ; drug effects ; Silicon Dioxide ; toxicity

OBJECTIVETo explore whether the superposition of an electromagnetic noise can block gap-junctional intercellular communication(GJIC) suppression induced by 50 Hz 0.4 mT extremely low frequency magnetic field(ELF MF).

METHODSFibroblast cells of mice(NIH 3T3) were exposed to 0.4 mT ELF MF or(and) electromagnetic noise with the same intensity of MF for 24 h, and the GJIC was determined by using fluorescence recovery after photobleaching(FRAP) analysis, which was performed with a laser-scanning confocal microscope(Leica, Germany).

RESULTSELF MF exposure significantly inhibited GJIC with fluorescence recovery rate of 27.67% +/- 5.12% as compared with the control group(45.57% +/- 9.72%) (P < 0.01), while that of ELF MF plus noise group was (52.61% +/- 8.30%), which was significantly different from ELF MF group(P < 0.01), but not from control(P > 0.05).

CONCLUSIONElectromagnetic noise could block the GJIC suppression induced by 50 Hz 0.4 mT MF.

Animals ; Cell Communication ; radiation effects ; Electromagnetic Fields ; adverse effects ; Gap Junctions ; radiation effects ; Mice ; NIH 3T3 Cells ; Noise ; adverse effects

OBJECTIVETo explore the effect of silica dioxide(SiO2) on proliferation and downregulation of gap junctional intercellular communication (GJIC) in pulmonary alveolar epithelial cells (CCL-64 cells).

METHODSThe pulmonary alveolar macrophages(PAMs) were incubated in the serum-free RPMI 1640 containing the various concentration of SiO2 for 24 hours. The supernatants were prepared and added 5% (V/V) into 2% (V/V) NBS RPMI 1640 to stimulate the proliferation of CCL-64 cells for 24 hours. A set of "blank control", run in parallel, contained RPMI 1640 + 2% (V/V) NBS alone. The proliferation of CCL-64 cells was detected using MTT assay(to show as the absorbency, A570nm). GJIC function was measured using the fluorescence redistribution after photobleaching(FRAP) assay [to express as the transfer rate of the fluorescence, K (x 10(-3)/s)], with a laser scanning confocal microscope(LSCM, Leica TCS SP).

RESULTSThe silica-exposed PAM supernatants could induce both the proliferation(F = 9.679, P < 0.01) and downregulation of GJIC(F = 20.587, P < 0.01) of CCL-64 cells. In the range of 50-500 micrograms/ml SiO2 concentrations, the proliferation (A570nm values) and GJIC(the transfer rate, K) were fitted well in a dose-dependent manner(proliferation: r = 0.891, P < 0.05; GJIC: r = -0.943, P < 0.05).

CONCLUSIONBy way of stimulating the PAM, SiO2 could inhibit GJIC function in lung alveolar epithelial cells, and induce epithelial cell proliferation. In the pathogenesis of silicosis, the downregulation of GJIC of the pulmonary epithelial cells may play an important role in silica-mediated alveolar epithelial cell injury.

Cell Communication ; drug effects ; Cell Proliferation ; drug effects ; Epithelial Cells ; drug effects ; Gap Junctions ; drug effects ; Pulmonary Alveoli ; drug effects ; Silicon Dioxide ; toxicity ; Silicosis ; etiology

OBJECTIVETo demonstrate the changes in gap junctional intercellular communication (GJIC) mediated by low power density microwave radiation in rabbits lens epithelial cells (LECs) and its mechanisms.

METHODSRabbits' eyes were exposed to 5 mW/cm(2) and 10 mW/cm(2) power densities of microwave radiation for 3 hours. The fluorescence-recovery-after-photobleaching (FRAP) method was used to determine the GJIC. The localization and function of connexin 43 in LECs was detected by laser scanning confocal microscopy.

RESULTSThe GJIC of rabbits LECs was inhibited by microwave radiation especially in the 10 mW/cm(2) irradiated samples. A decrease in connexin 43-positive staining was seen in 5 mW/cm(2) x 3 h treated LECs. Intracellular space accumulation and cytoplasmic internalization were clearly demonstrated in 10 mW/cm(2) group.

CONCLUSIONSLow power densities microwave radiation (5 mW/cm(2) and 10 mW/cm(2)) induces damage to connexin 43 and inhibits the GJIC of rabbits LECs. These changes result in an osmotic imbalance within the lens and induce early cataract. 5 mW/cm(2) or 10 mW/cm(2) microwave radiation is cataractogenic.

Animals ; Cataract ; etiology ; Cell Communication ; radiation effects ; Connexin 43 ; analysis ; Epithelial Cells ; radiation effects ; Fluorescent Antibody Technique, Indirect ; Gap Junctions ; radiation effects ; Lens, Crystalline ; radiation effects ; Microwaves ; adverse effects ; Rabbits

BACKGROUNDIt has been known that different degrees of hypoxia can produce different effects on tumor. The study is to investigate the effect of hypoxia on the infiltration and migration of lung adenocarcinoma cells.

METHODSLung adenocarcinoma cells were exposed to normoxic (air, 5%O₂), hypoxic (1%O₂, 5%CO₂, 94%N₂) or anoxic (95%N₂, 5%CO₂) condition for 48 hours. The migration ability of the cells was assayed by wound healing methods. The infiltration ability was assayed by HABM-HEM model. The cells exposed to hypoxia were planted subcutaneously in nude mice, and the growth of cells and the rate of metastasis to lymph node or lung were observed. The levels of matrix metalloproteinase 2 (MMP-2) and tissue inhibitor of metalloproteinase II (TIMP-2) in culture media were assayed by ELISA.

RESULTSComparing with normoxia group, the infiltration, migration and metastasis of hypoxia group were increased significantly (P < 0.05) , as well as the level of MMP-2 (P < 0.01), and the TIMP-2 level was remarkably decreased (P < 0.05) . In anoxia group, the levels of MMP-2 and TIMP-2 were both significantly decreased (P < 0.01).

CONCLUSIONSModerate hypoxia can up-regulate the expression of MMP-2, down-regulate the expression of TIMP-2, and increase the infiltration and migration of lung cancer cells. But serious hypoxia can decrease the expression of MMP-2 and TIMP-2, and inhibit the proliferation, infiltration and migration of lung cancer cells.

OBJECTIVETo study the effects of extremely low frequency magnetic fields(ELF MF) on the amount and localization of connexin 43(Cx43) gap-junction protein in the Chinese hamster lung(CHL) cells, and to explore the mechanism of ELF MF suppression on gap-junctional intercellular communication(GJIC).

METHODSThe cells were irradiated for 24 h with 50 Hz sinusoidal magnetic field at 0.8 mT without or with 12-O-tetrade-canoylphorbol-3-acetate(TPA), 5 ng/ml for 1 h. The localization of Cx43 proteins were performed by indirect immunofluorescence histochemical analysis and detected by confocal microscopy. The second experiment was conducted to examine the quantity of Cx43 proteins level in nuclei or cytoplasm and detected by Western blotting analysis.

RESULTSThe cells exposed to TPA for 1 h displayed less bright labelled spots in the regions of intercellular junction than the normal cells. Most of Cx43 labelled spots occurred in the cytoplasm and aggregated near the nuclei. At the same time, the amount of Cx43 protein in cytoplasm were increased[(2.03 +/- 0.89) in ELF group, (2.43 +/- 0.82) in TPA group] as compared to normal control(1.04 +/- 0.17) (P < 0.01).

CONCLUSIONInhibition on GJIC function by ELF MF alone or combined with TPA may be related with the shift of Cx43 from the regions of intercellular junction to the cytoplasm.

Animals ; Cell Communication ; radiation effects ; Connexin 43 ; biosynthesis ; Cricetinae ; Cricetulus ; Cytoplasm ; metabolism ; Electromagnetic Fields ; adverse effects ; Gap Junctions ; radiation effects ; Lung ; metabolism ; radiation effects ; Tetradecanoylphorbol Acetate ; pharmacology

Activating transcription factor 3 (ATF3) belongs to the transcription factor ATF/CREB family and is a stress-induced adaptive response gene. ATF3 is involved in the regulation of various cell activities to adapt to the changes in intracellular and extracellular environments. Recent studies have shown that ATF3 plays an important role in the development and progression of various chronic liver diseases, including nonalcoholic fatty liver disease, liver fibrosis, and liver cancer, by regulating gluconeogenesis, lipid metabolism, and immune function. This article reviews the mechanism of action of ATF3 in chronic liver diseases.