Cells, Cultured ; Fibroblasts ; cytology ; drug effects ; metabolism ; Humans ; Lung ; cytology ; metabolism ; Macrophages, Alveolar ; metabolism ; Matrix Metalloproteinase 2 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Silicon Dioxide ; toxicity ; Silicosis ; metabolism

OBJECTIVETo investigate the relationship between the hormesis of proliferation and oxidative stress induced by sodium arsenite (Na(2)AsO(2)) in human embryo lung fibroblasts (HELF).

METHODSHELF were treated with Na(2)AsO(2) of 0.0, 0.1, 0.5, 1.0, 5.0 and 10.0 micromol/L for 4 hours or 24 hours, respectively. The cell proliferation, the reactive oxygen species (ROS) level, the malondialdehyde (MDA) content and the activity of glutathione peroxide (GSH-Px) and the superoxide dismutase (SOD) in HELF were detected respectively.

RESULTSThe HELF proliferation induced by 0.1 and 0.5 micromol/L Na(2)AsO(2) was significantly higher than that in the control group (P < 0.01). The HELF proliferation induced by 5.0 and 10.0 micromol/L Na(2)AsO(2) was significantly lower than that in the control group (P < 0.01) with the dose-effect relation of an inverted U curve. The ROS level induced by Na(2)AsO(2) of between 0.5 and 10.0 micromol/L was significantly increased (P < 0.05, P < 0.01). The positive correlation was found between the ROS level and the exposure dose of Na(2)AsO(2) (r = 0.934, P < 0.01). The 5.0 and 10.0 micromol/L Na(2)AsO(2) induced the significant increase of the MDA contents (P < 0.01) and the significant decrease of the GSH-Px activity compared to those in the control group (P < 0.01). The SOD activity in 0.5 micromol/L Na(2)AsO(2) group was significantly higher than that in the control group (P < 0.01) while the SOD activity induced by 5.0 and 10.0 micromol/L Na(2)AsO(2) was significantly decreased (P < 0.01) if compared with the control group with the dose-effect relation of an inverted U curve.

CONCLUSIONThe sodium arsenite can induce the hormesis of proliferation in HELF with the dose-effect relation of an inverted U curve. The mechanisms probably relates to different levels of oxidative stress induced by sodium arsenite of different concentrations.

Arsenites ; toxicity ; Cell Proliferation ; drug effects ; Cells, Cultured ; Dose-Response Relationship, Drug ; Fibroblasts ; cytology ; drug effects ; metabolism ; Glutathione Peroxidase ; metabolism ; Humans ; Lung ; cytology ; embryology ; Malondialdehyde ; metabolism ; Oxidative Stress ; drug effects ; Reactive Oxygen Species ; metabolism ; Sodium Compounds ; toxicity ; Superoxide Dismutase ; metabolism

Pulmonary hypertension (PH) is characterized by structural and functional changes in the lung including proliferation of vascular smooth muscle cells (VSMCs) and excessive collagen synthesis. Although connective tissue growth factor (CTGF) is known to promote cell proliferation, migration, adhesion, and extracellular matrix production in various tissues, studies on the role of CTGF in pulmonary hypertension have been limited. Here, we examined CTGF expression in the lung tissues of male Sprague Dawley rats treated with monocrotaline (MCT, 60 microgram/kg), a pneumotoxic agent known to induce PH in animals. Establishment of PH was verified by the significantly increased right ventricular systolic pressure and right ventricle/left ventricle weight ratio in the MCT-treated rats. Histological examination of the lung revealed profound muscular hypertrophy in the media of pulmonary artery and arterioles in MCT-treated group. Lung parenchyma, vein, and bronchiole did not appear to be affected. RT-PCR analysis of the lung tissue at 5 weeks indicated significantly increased expression of CTGF in the MCT-treated group. In situ hybridization studies also confirmed abundant CTGF mRNA expression in VSMCs of the arteries and arterioles, clustered pneumocytes, and infiltrated macrophages. Interestingly, CTGF mRNA was not detected in VSMCs of vein or bronchiole. In saline-injected control, basal expression of CTGF was seen in bronchial epithelial cells, alveolar lining cells, and endothelial cells. Taken together, our results suggest that CTGF upregulation in arterial VSMC of the lung might be important in the pathogenesis of pulmonary hypertension. Antagonizing the role of CTGF could thus be one of the potential approaches for the treatment of PH.
Animals ; Blood Pressure/drug effects ; Bronchi/cytology/drug effects/metabolism ; Endothelial Cells/cytology/drug effects/metabolism ; Epithelial Cells/cytology/drug effects/metabolism ; Hypertension, Pulmonary/chemically induced/*metabolism ; Immediate-Early Proteins/genetics/*metabolism ; Intercellular Signaling Peptides and Proteins/genetics/*metabolism ; Lung/cytology/drug effects/*metabolism ; Male ; Monocrotaline/*toxicity ; Pulmonary Alveoli/cytology/drug effects/metabolism ; Pulmonary Artery/cytology/drug effects/metabolism ; Rats ; Rats, Sprague-Dawley ; Research Support, Non-U.S. Gov't ; Reverse Transcriptase Polymerase Chain Reaction ; Up-Regulation

OBJECTIVETo observe the effects of complement fragment C3f on expression and secretion of collagen I, III and transforming growth factor( TGF)-beta1 in human embryonic lung fibroblast (MRC-5) cells.

METHODSMRC-5 cells were cultured with C3f (the synthetic 17 peptides fragments of complement C3). The extracellular and intracellular expression levels of type I, III collagens and TGF-beta1 in MRC-5 cultures were detected by ELISA and immunohistochemistry, respectively.

RESULTSThe expression levels of type I, III collagen and TGF-beta1 in the supernatant of MRC-5 cultures decreased significantly with the concentrations of C3f as compared with controls (P < 0.05). Also the expression level of TGF-beta1 in MRC-5 cytoplasm reduced significantly as compared with controls (P < 0.05).

CONCLUSIONThe results of present in vitro study showed that the complement fragment C3f could reduce the formation of TGF-beta1 and type I, III collagens in MRC-5 cells, and inhibit the lung tissue fibrosis.

Cell Line ; Collagen Type I ; metabolism ; Collagen Type III ; metabolism ; Complement C3b ; pharmacology ; Fibroblasts ; drug effects ; metabolism ; Humans ; Lung ; cytology ; drug effects ; embryology ; Transforming Growth Factor beta1 ; metabolism

OBJECTIVETo study the expression and significance of fragile histidine triad (FHIT) and Ki-67 in transformed epithelial cells induced by Yunnan tin mine dust.

METHODSEvery second generation of immortalized human bronchial epithelial cells (BEAS-2B) and human embryo lung fibroblasts (WI-38) were exposed to 100 µg/ml Yunnan tin mine dust for 72 h, until the ninth generation. The cells were subsequently co-cultured from the 11th generation. Experimental setup: B group, B (W) group, B (W 100) group, B100 group, B100 (W) group, B100 (W100) group. The expressions of FHIT and Ki-67 in epithelial cells were determined by the method of immunocytochemistry at the 16th, 26th and 36th generation. The percentage of Ki-67 positive cells was calculated as proliferation index.

RESULTSThe expression of FHIT was observed in BEAS-2B cells. The expression levels of FHIT among B group, B (W) group and B (W 100) group had not instinctive difference. At the 16th generation, the expression of FHIT in the B100 group was decreased compared with that in the B group and the expression of FHIT between B100 (W) group and B100 (W100) group was lower than that in the B100 group. At the 26th generation, the expression of FHIT was decreased compared with that at the 16th generation in the B100, B100 (W) and B100 (W100) groups. However, At the 36th generation, positive expression were observed again in the B100, B100 (W) and B100 (W100) groups and the expression levels were in incremental order. At the 16th, 26th and 36th generation, the proliferation indexes of B group, B (W) group and B (W 100) group were all < 3%. The proliferation indexes of B100, B100 (W) and B100 (W100) were increased step by step with the generation elongation.

CONCLUSIONSFHIT could be a target at which Yunnan tin mine dust induces transformation of BEAS-2B cells. The proliferation activation of BEAS-2B cells can be improved by Yunnan tin mine dust.

Acid Anhydride Hydrolases ; metabolism ; Cell Line ; Cell Transdifferentiation ; China ; Dust ; Epithelial Cells ; cytology ; drug effects ; metabolism ; Humans ; Ki-67 Antigen ; metabolism ; Lung ; cytology ; Neoplasm Proteins ; metabolism ; Tin ; toxicity

OBJECTIVETo explore the differences of the silica-induced inhibition on cellular proliferation and hprt gene mutagenesis between lung fibroblasts and alveolar type II cells.

METHODSThe proliferation inhibitive cytotoxicity was detected by MTT (3-[4,5-Dimethylthiazolzyl]-2,5-Diphenyl Tetrazolium Bromide) colorimetric method. Mutation in the hprt gene was screened by culture in the presence of the toxic purine analog, 6-thioguanine (6-TG).

RESULTSUnder the same circumstances of silica exposure, alveolar type II cells was more sensitive than lung fibroblasts for proliferation inhibition. The median proliferation inhibition concentration (IC50) of silica on epithelial was 140 micrograms/cm2, whereas IC50 of silica on fibroblasts was 282 micrograms/cm2. At the same doses of silica, the hprt gene mutation frequency in type II cells (84.2 x 10(-6))-156.6 x 10(-6) was statistically higher than that in fibroblasts (67.6 x 10(-6)-114.3 x 10(-6), P < 0.05).

CONCLUSIONThere were significant differences of both silica-induced cell proliferation inhibition and hprt gene mutation between rat lung fibroblasts and type II epithelial cells. In vitro, cultured rat alveolar type II cells were more sensitive in cytotoxicity and hprt gene mutagenesis to silica dust than lung fibroblasts were.

Animals ; Cell Proliferation ; drug effects ; Epithelial Cells ; drug effects ; Fibroblasts ; drug effects ; Hypoxanthine Phosphoribosyltransferase ; genetics ; Lung ; cytology ; drug effects ; metabolism ; Mutation ; Pulmonary Alveoli ; cytology ; drug effects ; Rats ; Silicon Dioxide ; toxicity

OBJECTIVETo investigate the alteration of activator protein-1 (AP-1) luciferase activity in human embryo lung fibroblasts (HELF) after exposed to silica, and the role of mitogen activated protein kinase (MAPK)/AP-1 pathway on silica-induced cell cycle changes.

METHODSAfter HELF cells were treated with 200 microg/ml silica, immunofluorescence assays were employed to detect the translocation and the phosphorylation level of extracellular signal-regulated protein kinase (ERK) and c-Jun N-terminal kinase (JNK), flow cytometry was used to detect the distributions of cell cycle, the dominant negative mutant of ERK, JNK and p38 were applied to detect the upstream or downstream relationship of signaling pathways.

RESULTSAfter HELF-AP-1 cells were exposed to 200 microg/ml silica 6, 12, 24 h respectively, silica exposure lead to AP-1 activation in a time-dependent manner, inducing significant AP-1 activation at 6 h, reaching a maximum activation at 12 h, and having a little decrease at 24 h. After silica exposure 1 h, phosphorylation level of ERK and JNK increased mainly in cytoplasm, however, after exposure 2 h, they translocated to nucleus. The proportion of cells in G1 phases was decreased from (63.80 +/- 9.57)% to (32.23 +/- 7.22)%, and the proportion of cells in S phases was increased from (35.17 +/- 10.33)% to (66.00 +/- 8.07)% after exposed to silica 24 h. Curcumin, a chemical inhibitor of AP-1, impaired the decrease of cells in G1 phases. Furthermore we found expression of dominant-negative mutant of ERK and JNK impaired silica-induced AP-1 activation, whereas, dominant-negative mutant of p38 did not show the effect.

CONCLUSIONThese result suggested that 200 microg/ml silica exposure can induce AP-1 activation, induce cell cycle changes through ERK, JNK/AP-1-dependent pathway.

Cell Cycle ; drug effects ; Cells, Cultured ; Extracellular Signal-Regulated MAP Kinases ; metabolism ; Fibroblasts ; cytology ; drug effects ; metabolism ; Humans ; JNK Mitogen-Activated Protein Kinases ; metabolism ; Lung ; cytology ; Quartz ; pharmacology ; Signal Transduction ; drug effects ; Transcription Factor AP-1 ; metabolism

OBJECTIVETo investigate the reverse effect of all-trans retinoic acid (ATRA) on Benzo (a) pyrene (B (a) P)-induced cyclin D1, CDK4, E2F-1 and E2F-4 expression and cell cycle progression in human embryo lung fibroblast (HELF).

METHODSAfter HELF cells was treated with ATRA, they were exposed to 2 micromol/L of B (a) P. Western blotting was employed to detect protein expression level; the RNA transfection techniques was used to investigate ATRA-induced signal pathway; flow cytometry was used to detect cell cycle progression.

RESULTAfter treatment with 2 micromol/L B (a) P for 24 h, the expression of cyclin D1 and E2F-1 were both increased significantly in HELF; the expression of E2F-4 and CDK4 were not changed markedly; pretreatment with 0.1 micromol/L ATRA for 24 h could efficiently decrease B (a) P-induced overexpression of cyclin D1 and E2F-1; stimulation to antisense cyclin D1 or antisense CDK4 by B (a) P could significantly impair E2F-1 up-regulation; pretreatment with ATRA, cells with antisense cyclin D1 or antisense CDK4 showed a less decrease in B (a) P-induced overexpression of E2F-1 compared to similarly treated control cells; flow cytometry analysis showed B (a) P promoted cell cycle progression from G(1) phase to S phase, while pretreatment with ATRA could inhibit B (a) P-induced cell cycle progression by an accumulation of cells in the G(1) phase.

CONCLUSIONATRA could block B (a) P-induced cell cycle promotion through cyclin D1/E2F-1 pathway in HELF.

Benzo(a)pyrene ; toxicity ; Cell Cycle ; drug effects ; Cells, Cultured ; Cyclin D1 ; metabolism ; E2F1 Transcription Factor ; metabolism ; Fibroblasts ; cytology ; drug effects ; metabolism ; Flow Cytometry ; Humans ; Lung ; cytology ; metabolism ; Signal Transduction ; drug effects ; Tretinoin ; pharmacology

OBJECTIVETo investigate the effect of salvianolic acid B (SAB) on the proliferation of human embryonic lung fibroblast MRC-5, and the secretion of procollagen I and endogenous transforming growth factor-beta1, (TGF-beta1).

METHODSThe MRC-5 cells were randomly divided into four groups as follows: the control group: cells cultured with DMEM but with no TGF-beta1, or SAB; the TGF-beta1, group: cell cultured with 10 ng/mL TGF-beta1; the SAB1 group: cell cultured with medium with 10 ng/mL TGF-beta1 and 1 pmol/L SAB; the SAB2 group: cell cultured with medium with 10 ng/mL TGF-beta1, and 10 pmol/L SAB. The proliferation of cells was assayed by MTT incorporation. The concentration of amino-terminal propeptide of type I procollagen (PINP), a marker of collagen synthesis, was measured by radioimmunoassay. The endogenous TGF-beta1, levels were measured using ELISA.

RESULTSThe optical density, procollagen I contents, and endogenous TGF-beta1, levels significantly increased when compared with those of the control group (P<0.05). Compared with the TGF-beta1, group, the optical density was obviously lowered, the procollagen I contents and endogenous TGF-beta1, levels significantly decreased in the SAB1 group and the SAB2 group, and better in the SAB2 group, showing statistical difference (P<0.05).

CONCLUSIONSSAB could inhibit the proliferation of MRC-5 cells induced by TGF-beta1 and attenuate the roles of secreting collagen and endogenous TGF-beta1. It had the potential of postponing or delaying the progressive developing of pulmonary fibrosis.

Benzofurans ; pharmacology ; Cell Proliferation ; drug effects ; Cells, Cultured ; Collagen Type I ; metabolism ; Fibroblasts ; cytology ; drug effects ; Humans ; Lung ; cytology ; embryology ; Transforming Growth Factor beta1 ; pharmacology

OBJECTIVE: To investigate the role of AP-1 in the secretion of Type I collagen in TGF-beta1-stimulated human lung fibroblasts. METHODS: Human lung fibroblasts cell line (HLF-02) was cultured, and then stimulated with 10 microg/L TGF-beta1 at different time points. Curcumin was added into the culture medium to inhibit the AP-1 activity before incubating with TGF-beta1. AP-1 DNA binding activity was assayed by electrophoretic mobility shift assay (EMSA), and the expression of Type I collagen was detected by Western blot and RT-PCR. RESULTS: TGF-beta1 could induce the transcription and secretion of Type I collagen in HLF-02 cells(P<0.05). TGF-beta1 could upregulate the AP-1 DNA binding activity ( P<0.05). Curcumin ( 5, 10, 15, and 20 micromol/L) could inhibit the AP-1 DNA binding activity in TGF-beta1-stimulated cells (the inhibition ratio was 17.1%, 17.6%, 24.2%, and 31.3%; P<0.05). Curcumin (5, 10, 15, and 20 micromol/L) could also inhibit the secretion of Type I collagen significantly (the inhibition ratio was 62.1%, 58.8%, 62.1%, and 59.6%; P<0.05). CONCLUSION AP-1 is responsible for the secretion of TGF-beta1-induced Type I collagen in human lung fibroblasts.
Cell Line ; Collagen Type I ; metabolism ; Fibroblasts ; cytology ; drug effects ; metabolism ; Humans ; Lung ; cytology ; Signal Transduction ; Transcription Factor AP-1 ; metabolism ; Transforming Growth Factor beta1 ; pharmacology