Small-scale fire tests in the underwater tunnel section model with new sidewall smoke extraction

The Shenzhen–Zhongshan Bridge is a 24‐km‐long bridge and tunnel system,including a 6.8-km-long super cross section subsea tunnel.To solve the smoke exhaust problem of a super large cross-section subsea tunnel,the tunnel has a new smoke exhaust system that combines a horizontal smoke exhaust cross section at the top and sidewall smoke exhaust holes.In order to evaluate the potential fire hazards of this type of tunnel,a 1:30 tunnel model was established and 140 smallscale experiments on underwater tunnel fires were conducted.By changing the fire power,fire location,and fan operation mode,different scenarios of submarine immersed tunnel fire were simulated and the related key parameters such as fire smoke diffusion behavior and smoke temperature distribution were studied.On this basis,the optimal smoke control strategy was proposed for different fire scenarios.The research results indicate that the new smoke exhaust system can fully utilize the smoke flow characteristics,significantly improve smoke exhaust efficiency,and increase available evacuation time,thus further enhancing the fire safety of super large cross-section subsea tunnels.

Dysregulation of gastric H,K-ATPase by cigarette smoke extract

AIM:To test whether the expression and activity of H,K-ATPase in parietal cells would be affected by cigarette smoke extract.METHODS: Extracts of cigarette smoke were administered into mice by gastric gavage (5 mg/kg body weight/day) for 3 d or in drinking water for 7 or 14 d. For the latter, each day a mouse consumed 5 mL water containing extracts of two cigarettes, on average. Control littermate mice received only vehicle. To compare the amount of H,K-ATPase in control and smoke-treated mice, the stomach was processed for Western blotting and immunohistochemical analysis using monoclonal antibodies specific for α- or β-subunits of H,K-ATPase. The p-nitrophenylphospatase activity assay was used as a measurement for K-dependent H,K-ATPase activity.RESULTS: Probed transblots showed an increase in the amount of H,K-ATPase in smoke-treated mice which was confirmed by immunohistochemistry and was found to be due to increased amounts of protein per parietal cell rather than an increased parietal cell number. The increase in the amount of H,K-ATPase was associated with an enhancement of its enzymatic activity. K-dependent activity in control and smoke-treated mice was significantly different (respectively, 0.12 μmol/mg vs 0.27 μmol/mg per minute, P<0.05).CONCLUSION: Administration of cigarette smoke extract is associated with an increase in the amount and activity of H,K-ATPase and hence, smokers are susceptible to development of peptic ulcer.

Damaging Effect of Cigarette Smoke Extract on PrimaryCultured Human Umbilical Vein Endothelial Cells and Its Mechanism

Objective To investigate the cellular effects of cigarette smoke extract (CSE) on primarily cultured human umbilical vein endothelial cells (HUVEC). Methods The effects of CSE (5%-20%) and nicotine (10-4 mol/L) on HUVEC viability, proliferation, angiogenesis and apoptosis were observed. Results CSE decreased HUVEC survival rate and angiogenesis after 24 h as well as its proliferation after 48 h in a dose-dependent manner. Moreover, CSE induced apoptosis of HUVEC as indicated in condensation of nuclear chromatin and the presence of hypodiploid DNA. HUVEC incubated with CSE for 24 h gave a significant decrease in the expression of Bcl-2 as well as the decline in the Bcl-2/Bax ratio accompanied with the loss of mitochondrial membrane potential and excess cytosolic calcium. Our study also observed that p53 protein level decreased, rather than increased in cells treated with CSE. Nicotine had no discernible inhibitory effects on the above indices of HUVEC. Conclusion Exposure to CSE other than nicotine causes inhibition of viability, proliferation and differentiation of HUVEC. CSE-induced HUVEC injury is mediated in part through accelerated apoptosis but independent of p53 pathway. It appears that mitochondria have played a key role in the apoptosis of HUVEC induced by CSE.

Effect of Cigarette Smoke Extract on the Role of Protein Kinase C in the Proliferation of Passively Sensitized Human Airway Smooth Muscle Cells

To investigate the effect of cigarette smoke extract (CSE) on the role of protein kinase C (PKC) in the proliferation of passively sensitized human airway smooth muscle cells (HASMCs). After synchronization of cultured HASMCs, they were divided into a group A and Group B. The group A was treated with normal human serum and served as controls and the group B was treated with the serum of asthma patients. The group A was further divided into group of A_1, A_2 and A_3 and the group B was sub-divided into the group of B_1, B_2, B_3, B_4 and B_5. No other agents were added to the group A_1 and B_1. The cells of group A_2 and B_2 were stimulated with 5 % CSE for 24 h. HASMCs from group A_3 and B_3 were treated with PKC agonist PMA (10 nmol/L) and CSE (5 %) for 24 h. PKC inhibitor Ro-31-8220 (5 μmol/L) was added to the HASMCs of group B_4 for 24 h. The cells from group B_5 were stimulated with Ro-31-8220 (5 μmol/L) and CSE (5 %) for 24 h. The proliferation of HASMCs isolated from group A and B was examined by cell cycle analysis, MTT colorimetric assay and 3H-TdR incorporation test. The expression of PKC-α in each group was observed by Western blotting and RT-PCR, respectively. The results showed that the percentage of S phase, absorbance (A) value, the rate of 3H-TdR incorporation, the ratios of A value of PKC-α mRNA and the A value of PKC-α protein in HASMCs from group B_1, B_2 and B_3 were significantly increased compared to those of group A_1, A_2 and A_3 correspondingly and respectively (P<0.01). The proliferation of HASMCs of group A_2 and B_2 stimulated with CSE and group A_3 and B_3 stimulated with CSE and PMA were also significantly enhanced when group A_1, A_2 and A_3 and group B_1, B_2 and B_3 compared to each other (P<0.05, P<0.01, respectively). The percentage of S phase, absorbency (A) value, 3H-TdR incorporation rate, the ratios of A value of PKC-α mRNA and the A value of PKC-α protein in HASMCs from group B_4 treated with Ro-31-8220 and group B_5 treated with CSE and Ro-31-8220 were significantly decreased as compared to those of group B_1 and B_2 correspondingly and respectively (P<0.05, P<0.01). It was concluded that CSE can enhance the passively sensitized HASMC proliferation and the expression of PKC alpha. PKC and its alpha subtype may contribute to this process. Our results suggest cigarette may play an important role in ASMCs proliferation of asthma through PKC signal pathway.

Injury of Mouse Brain Mitochondria Induced by Cigarette Smoke Extract and Effect of Vitamin C on It in vitro

Objective To investigate the toxicity of cigarette smoke extract (CSE) and nicotine on mouse brain mitochondria as well as the protective effect of vitamin C in vitro. Method Mouse brain mitochondria in vitro was incubated with CSE or nicotine in the absence or presence of vitamin C for 60 minutes, and the changes of mitochondrial function and structure were measured. Results CSE inhibited mitochondrial ATPase and cytochrome C oxidase activities in a dose-dependent manner. However, no significant changes in the peroxidation indices were observed when mitochondrial respiratory enzymes activity was inhibited, and protection of mitochondria from CSE-induced injury by vitamin C was not displayed in vitro. The effect of CSE on mouse brain mitochondria swelling response to calcium stimulation was dependent on calcium concentrations. CSE inhibited swelling of mitochondria at 6.5μmol/L Ca2+, but promoted swelling response at 250μmol/L Ca2+. Nicotine, the major component of cigarette smoke, showed no significant damage in mouse brain mitochondria in vitro. The CSE treatment induced mitochondrial inner membrane damage and vacuolization of the matrix, whereas the outer mitochondrial membrane appeared to be preserved. Conclusion The toxic effect of CSE on brain mitochondria may be due to its direct action on enzymatic activity rather than through oxygen free radical injury. Nicotine is not the responsible component for the toxicity of CSE to brain mitochondria.

Roles of TGF-β Signaling Pathway in Endoplasmic Reticulum Stress in Endothelial Cells Stimulated with Cigarette Smoke Extract

To investigate the role of signaling pathway in the effect of endoplasmic reticulum stress（ER stress） in endothelial cells stimulated with cigarette smoke extract（CSE）. Human umbilical vein endothelial cells（HUVECs） were cultured and divided into 3 groups： CSE-stimulated group, CSE-stimulated with 4-PBA group, and negative control group. HUVECs were cultured and stimulated with CSE at concentrations of 5%, 10% and 20%, respectively, mR NA of CXCL-8 and GRP78 was detected by real-time PCR. ELISA was performed to test the expression of CXCL-8 protein, and neutrophils migration was detected by Transwell board test. The NF-κB, ERK, p38 MAPK and transforming growth factor beta（TGF-β） were detected by flow cytometry. The mRNA of CXCL-8 and GRP78 increased in CSE-stimulated HUVECs（P〈0.05）. Furthermore, it was concentration-dependent. 4-PBA significantly reduced the expression of CXCL-8 protein（P〈0.05） and neutrophil migration（P〈0.05）. The TGF-β, rather than the NF-κB, ERK and P38 MAPK pathway might be involved in ER stress stimulated by CSE. CSE induced neutrophils migration by increasing the expression of CXCL-8 in endothelial cells. ER stress might play a role in the effect of neutrophils migration stimulated with CSE, and TGF-β pathway may contribute to the ER stress in HUVECs.

Genotoxicity and Reduced Heat Shock Protein 70 in Human Airway Smooth Muscle Cells Exposed to Cigarette Smoke Extract

Cigarette smoke is associated with the development of several diseases, such as chronic ob- structive pulmonary disease （COPD）. The purpose of this study was to investigate genotoxicity and heat shock protein 70 （Hsp70） in human airway smooth muscle cells （HASMCs） exposed to cigarette smoke extract （CSE）. HASMCs was exposed to CSE with different doses for 24 h. The level of 8-hydroxydeoxyguanosine （8-OHdG） was determined by using HPLC-ECD, the DNA damage was ana- lyzed by using comet assay, and apoptosis was examined by using Annexin-FITC/PI staining. The pro- duction of Hsp70 after CSE stimulation was tested. Results indicated that CSE significantly increased the level of 8-OHdG, DNA damage and cell apoptosis, and reduced the production of Hsp70. In par- ticular, levels of Hsp70 were inversely correlated with 8-OHdG, DNA damage and cell apoptosis. It was concluded that cigarette smoke induced genotoxicity and decreased the production of cell protective protein Hsp70, which may contribute to the development of some airway diseases.

Cigarette Smoke Extract Inhibits the Proliferation of Alveolar Epithelial Cells and Augments the Expression of P21^(WAF1)

Cigarette smoking is intimately related with the development of chronic obstructive pulmonary diseases, and alveolar epithelium is a major target for the exposure of cigarette smoke extract. In order to investigate the effect of cigarette smoke extract on the proliferation of alveolar epithelial cell type Ⅱ and its relationship with P21^WAF1, the alveolar epithelial type Ⅱ cell line （A549） cells were chosen as surrogate cells to represent alveolar epithelial type Ⅱ cells. MTT assay was used to detect cell viability after interfered with different concentrations of cigarette smoke extract. It was observed cigarette smoke extract inhibited the growth of A549 cells in a dose- and time-dependent manner. The morphological changes, involving the condensation and margination of nuclear chromatin, even karyorrhexis, were observed by both Hoechst staining and electronic microscopy. Flow cytometry analysis demonstrated the increased cell percentages in G1 and subG1 phases after the cells were incubated with cigarette smoke extract. The expression of p21^WAF1 protein and mRNA was also significantly increased as detected by the methods of Western blot or reverse transcription-polymerase chain reaction respectively. In conclusion, cigarette smoke extract inhibits the proliferation of alveolar epithelial cell type Ⅱ and blocks them in G1/S phase. The intracelhilar accumulation of P21^WAF1 may be one of the mechanisms which contribute to cigarette smoke extract-induced inhibition of cell proliferation.

Involvement of TRPC1 and Cyclin D1 in Human Pulmonary Artery Smooth Muscle Cells Proliferation Induced by Cigarette Smoke Extract

Cigarette smoking contributes to the development of pulmonary artery hypertension(PAH).As the basic pathological change of PAH,pulmonary vascular remodeling is considered to be related to the abnormal proliferation of pulmonary artery smooth muscle cells(PASMCs).However,the molecular mechanism underlying this process remains not exactly clear.The aim of this research was to study the molecular mechanism of PASMCs proliferation induced by smoking.Human PASMCs(HPASMCs)were divided into 6 groups:0%(control group),cigarette smoking extract(CSE)-treated groups at concentrations of 0.5%,1%,2%,5%,10%CSE respectively.HPASMCs proliferation was observed after 24 h.HPASMCs were divided into two groups:0(control group),0.5%CSE group.The mRNA and protein expression levels of transient receptor potential channel 1(TRPC1)and cyclin D1 in HPASMCs after CSE treatment were respectively detected by RT-PCR and Western blotting.The intracellular calcium ion concentration was measured by the calcium probe in each group.In the negative control group and TRPC1-siRNA transfection group,the proliferation of HPASMCs and the expression of cyclin D1 mRNA and protein were detected.Data were compared with one-way ANOVA(for multiple-group comparison)and independent t-test(for two-group comparison)followed by the least significant difference(LSD)test with the computer software SPSS 17.0.It was found that 0.5%and 1%CSE could promote the proliferation of HPASMCs(P<0.05),and the former was more effective than the latter(P<0.05),while 3%and above CSE had inhibitory effect on HPASMCs(P<0.05).The mRNA and protein expression levels of TRPC1 and cyclin D1 in 0.5%and 1%CSE groups were significantly higher than those in the control group(P<0.05),while those in 3%CSE group were significantly decreased(P<0.05).Moreover,the proliferation of HPASMCs and the expression of cyclin D1 mRNA and protein in TRPC1-siRNA transfection group were significantly reduced as compared with those in the negative control group(P<0.05).It was concluded that low concentration of CSE can promote the proliferation of HPASMCs,while high concentrations of CSE inhibit HPASMCs proliferation.These findings suggested that CSE induced proliferation of HPASMCs at least in part via TRPC1-mediated cyclin D1 expression.

Effect of Cigarette Smoke Extract on the Proliferation of Human Airway Epithelial Cells and Expression and Activation of FAK

The effect of cigarette smoke extract (CSE) on the proliferation of human airway epithelial cells and the possible mechanism was studied. After airway epithelial cells were treated with different concentrations of CSE for 24 h, the cell proliferation was measured by MTT and the distribution of different cell cycles by flow cytometry. The FAK expression level was detected by Western blot and the degree of tyrosine phosphorylation by immunoprecipitation. The results showed that CSE could inhibit the proliferation of human airway epithelial cells, arrest the epithelial cells in G1 phase of cell cycle, dramatically decrease the number of epithelial cells in S and G2 phases; Meanwhile CSE could decrease the expression level of FAK and the degree of its tyrosine phosphorylation. The above effects of CSE were concentration-dependent. The expression of FAK and the degree of its phosphorylation was positively correlated to the increased number of epithelial cells in G1 phase, and negatively to the number of epithelial cells in S and G2 phases. It was concluded that the mechanism by which CSE could inhibit the proliferation of human epithelial cells was contributed to the increased expression and activation of FAK.

Cigarette smoke extract-induced 16HBE-derived exosomal miR-186 significantly promoted the proliferation of COPD MRC-5 cell

Objective:To study the effect of cigarette extract(CSE)on the expression of exosomal miR-186 derived from 16HBE cells and the effects of 16HBE-derived exosomal miR-186 on the proliferation of MRC-5 cells.Methods:To collect the exosomal miR-186 in the supernatant of CSE-treated 16HBE cells for MRC-5 cell culture;the expression of exosomal miR-186 was detected by qPCR;the proliferation of MRC-5 cell was detected by CCK-8;dual-luciferase reporter gene experiment was used to detect the targeted regulation relationship between miR-186 and Bcl2L11;the expression of Bcl2L11 was detected by Western blot.Results:The morphology of 16HBE cells about 100 nm in diameter were observed by TEM;CSE treatment significantly promoted the expression of exosomal miR-186;CSE-induced exosomal miR-186 promoted the proliferation of MRC-5 cells;Bcl2L11 is a target gene of miR-186;miR-186 mimics significantly decreased Bcl2L11 expression.Conclusion:CSE-induced 16HBE-derived exosomal miR-186 promoted the proliferation of MRC-5 cells by targeting Bcl2L11 genes.

An assessment for the viability of recovering heat from a smoke extract system

Over the course of industrial manufacturing,additional heat within the extract systems is usually released into the atmosphere and its intrinsic energy is wasted.This paper investigated a cold abatement smoke extract system for a fire testing wall furnace to determine the viability in recovering heat from the hot smoke.Three scenarios were investigated:1)the extract system was closed and only 300°C smoke was present;2)the system took in ambient air around the furnace and heat recovery occurred at 80°C in smoky air;3)the smoke had been removed from the air and the temperature was 60°C.It was found that there was a significant build-up of soot on Scenarios 1&2 with a build-up rate of 0.25𝜇m/s which totalled 2.7 mm of soot after a three-hour test.The soot had a low heat transfer rate and therefore acted as an insulator on the heat exchanger which reduced the efficiency significantly of it over time.Due to this loss in efficiency,it was more viable to recover heat in Scenario 3 at 60°C in clean air than it was to recover heat at 300°C or 80°C in smoky air.The results show that having clean air was more important than a higher temperature when it came from recovering heat from a cold abatement system for a fire testing furnace.This paper contributes to reveal the possibilities of harnessing the“waste heat”for use in other applications in the vicinity of the manufacturing processes,such as heating water within a central heating plant,domestic hot water or electricity generation,or re-cycled within the industrial plant itself.

Effect of cigarette smoke extraction on the expression of found in inflammatory zone 1 in rat lung epithelial L2 cells

Background Found in inflammatory zone 1 （FIZZ1） protein increased in pulmonary epithelial cells and in limited amounts of other lung cells.FIZZ1 increased in murine model of smoke induced chronic obstructive pulmonary disease.However,the direct role of FIZZ1 produced by pulmonary epithelium stimulated with cigarette smoke extraction has not been determined.We examined the expression and function of FIZZ1 in rat lung epithelial L2 cells.Methods The rat lung epithelial L2 cells （CCL 149） were exposed to cigarette smoke extraction,expression of FIZZ1 mRNA was investigated by RT-PCR.Levels of FIZZ1 protein were detected by Western blotting and laser confocal microscope.CCL 149 cells were treated with different concentrations and for different time of recombinant protein FIZZ1.After treatment,the expression levels of interleukin 8 （IL-8） were detected by enzyme-linked immunosorbent assay （ELISA）.Results When CCL 149 cells were exposed to cigarette smoke extraction,FIZZ1 mRNA and protein levels expressed significantly higher than control group.Recombinant protein FIZZ1 promoted the expression of IL-8 in a dose and time dependent manner in a certain range.Conclusions Cigarette smoke extraction activates FIZZ1 at mRNA and protein levels in CCL 149 cells.Recombinant protein FIZZ1 induces the expression of IL-8 and may thus participate in the process of chronic obstructive pulmonary disease airway inflammation and airflow obstruction.Generally,immune cells such as macrophages,neutrophils and lymphocytes are unavoidably involved in airway inflammatory and immune responses to cigarette smoke,but it is still unclear whether their involvement in the pathogenesis of chronic obstructive pulmonary disease is based on the specific expression in lung epithelial cells of FIZZ1.

Expression of Heat Stress Protein 70 mRNA in Patients with Chronic Obstructive Pulmonary Disease and Its Significance

The effects of cigarette smoke extract (CSE) on the expression of heat stress protein 70 (Hsp70) in human bronchi smooth muscle cells were investigated in vitro, and the changes in Hsp70 mRNA in the patients with chronic obstructive pulmonary disease and their significance were explored. Human bronchi smooth muscle cells were cultured with CSE at the different concentrations. The expression of Hsp70 mRNA and Hsp70 was detected by reverse translation-polymerase chain reaction (RT-PCR) and Western blotting respectively. Levels of Hsp70 mRNA and Hsp70 in lymphocytes from 20 patients with COPD and 20 healthy smoking control subjects were measured by RT-PCR and Western blotting. The results showed the expression of both Hsp70 mRNA and Hsp70 was decreased conformably in human bronchi smooth muscle cells treated with CSE at certain concentration in vitro. The A values of the Hsp70 mRNA expression were 0.24±0.11 and 0.42±0.13 respectively in COPD patients and healthy smoking controls with the difference being significant (P<0.01). There was also significant difference in the A values of the Hsp70 expression between COPD patients and healthy smoking controls (20.9±9.9 vs 44.8±15.3, P<0.01). The levels of Hsp70 mRNA had strongly positive correlation with Hsp70 protein (r = 0.85, P<0 01). It was suggested that the expression of Hsp70 mRNA was in concordance with the expression of Hsp70, which could provide a basis on the study of Hsp70 gene regulation and Hsp70 gene in the development of COPD.

Cluster Analysis of Polyphenols and Organic Acids in 11 Different Brand Cigarette Samples at Home and Abroad

The objective of this research was to investigate the differences between local cigarette and foreign cigarette and supplied a base for improving the quality of cigarette. Different kinds of polyphenols and organic acids in 11 different brand cigarette samples at home and abroad were classified by the method of cluster analysis. The results indicated that the 11 samples could be classified into 2 classes. Suyan, Furongwang, Chinese, Baisha, Dihao, Yunyan, Hongtashan belonged to type 1; foreign cigarettes that represented by Marboro, Blue pacific and Brazil cigarette belonged to type 2. The content of malic acid and citric acid in type 1was higher than type 2, the content of malonic acid was higher in type 2, and there is no difference between the type 1 and type 2 about the content of polyphenols. In conclusion, the content of malic acid and citric in Chinese cigarettes was higher than foreign, but the content of malonic acid was lower than foreign. There is no difference between Chinese cigarettes and foreign cigarettes about the content of polyphenols.

Effects of simvastatin on cigarette smoke extract induced tissue-type plasminogen activator and plasminogen activator inhibitor-1 expression in human umbilical vein endothelial cells

Background Cigarette smoking has an influence on both arterial-type and venous-type thrombosis. However, little is known about the direct effect of cigarette smoke extract （CSE） on fibrinolytic activity of human umbilical vein endothelial cells （HUVECs）. Most recently, simvastatin has been marked in its effect on endothelial cells protection and anticoagulation. In this study, the effect of CSE on the expression of tissue-type plasminogen activator （t-PA） and plasminogen activator inhibitor-l（PAl-1） in HUVECs was addressed. The role of simvastatin in CSE-induced fibrinolytic activity changes was investigated as well. Methods The fourth to fifth generation of HUVECs were incubated respectively with 0, 5%, 10% and 20% CSE for 6 hours or exposed to 5% CSE for 0, 4, 6, 8, 12, 24 hours to determine the expression changes of t-PA and PAl-1 protein. Meanwhile, cells were also accordingly exposed either to 5% CSE alone or simvastatin pre-treated and 5% CSE for 24 hours to assess the role of simvastatin in CSE-induced t-PA and PAl-1 protein and mRNA expression in HUVECs. RT-PCR and ELISA techniques were used for detecting the t-PA or PAl-1 mRNA and protein. Results After 6-hour exposure to CSE, the expression levels of t-PA protein in 10% and 20% CSE-treated groups reduced significantly （（0.0365±0.0083） ng/ml, （0.0255±0.0087） ng/ml） when compared with that of control group （（0.0660±0.0120） ng/ml） （P 〈0.05）. In contrast, the levels of PAl-1 protein in 5%, 10% and 20% CSE-treated groups increased remarkably （（13.3225±0.5680） ng/ml, （14.2675±1.5380） ng/ml, （14.4292±1.6230） ng/ml） when compared with that of control group （（8.5193_±0.7537）ng/ml） （P〈0.05）. After stimulation with 5% CSE for 0, 4, 6, 8, 12, 24 hours, the levels of PAl-1 protein increased over time and reached the peak at 24 hours （（14.6400±1.0651） ng/ml）, which was significantly higher than that of control group （（12.0656±0.6148） ng/ml） （P 〈0.05）. Additionally, CSE could up-regulate PAl-1 expression at both the mRNA and the protein levels. The levels of PAl-1 mRNA and protein increased significantly in 5% CSE-treated group （（8.8030±0.4745） ng/ml, （1.8155±0.0412） ng/ml） compared with those of control groups （（5.0588±0.2315） ng/ml, （1.3030±0.0647） ng/ml） （P 〈0.01）, and decreased after 2-hour simvastatin pre-treatment （（5.4875±0.3166） ng/ml, （1.3975-±0.0297） ng/ml） （P 〈0.01）. No significant difference was found at the levels of t-PA protein and mRNA （P 〉0.05）. Conclusions CSE inhibits the fibrinolytic activity of HUVECs in vitro. Simvastatin plays a protective role in CSE-induced fibrinolytic malfunction.

The effect of cigarette smoke extract on thrombomodulinthrombin binding: an atomic force microscopy study

Cigarette smoking is a well-known risk factor for cardiovascular disease. Smoking can cause vascular endothelial dysfunction and consequently trigger haemostatic activation and thrombosis. However, the mechanism of how smoking promotes thrombosis is not fully understood. Thrombosis is associated with the imbalance of the coagulant system due to endothelial dysfunction. As a vital anticoagulation cofactor, thrombomodulin (TM) located on the endothelial cell surface is able to regulate intravascular coagulation by binding to thrombin, and the binding results in thrombosis inhibition. This work focused on the effects of cigarette smoke extract (CSE) on TM-thrombin binding by atomic force microscopy (AFM) based single-molecule force spectroscopy. The results from both in vitro and live-cell experiments indicated that CSE could notably reduce the binding probability of TM and thrombin. This study provided a new approach and new evidence for studying the mechanism of thrombosis triggered by cigarette smoking.

Cigarette smoke extract promotes proliferation of airway smooth muscle cells in asthmatic rats via regulating cyclin D1 expression

Background Increased proliferation of airway smooth muscle cells （ASMCs） are observed in asthmatic patients and smoking can accelerate proliferation of ASMCs in asthma. To elucidate the molecular mechanisms leading to these changes, we studied in vitro the effect of cigarette smoke extract （CSE） on the proliferation of ASMCs and the expression of cyclin D1, an important regulatory protein implicated in cell cycle. Methods ASMCs cultured from 8 asthmatic Brown Norway rats were studied. Cells between passage 3 and 6 were used in the study and were divided into control group, pcDNA3.1 group, pcDNA3.1-antisense cyclin D1 （ascyclin D1） group, CSE group, CSE＋pcDNA3.1 group and CSE＋pcDNA3.1-ascyclin D1 group based on the conditions for intervention. The proliferation of ASMCs was examined with cell cycle analysis, MTT colorimetric assay and proliferating cell nuclear antigen （PCNA） immunocytochemical staining. The expression of cyclin D1 was detected by reverse transcriptase-PCR （RT-PCR） and Western blotting. Results （1） The percentage of S＋G2M phase, absorbance value at 490 nm wavelength （A490） and the expression rate of PCNA protein in CSE group were （31.22±1.17）%, 0.782±0.221, （90.2±7.0）% respectively, which were significantly increased compared with those of control group （18.36±1.02）%, 0.521±0.109, and （54.1±3.5）%, respectively） （P 〈0.01）. After the transfection with antisense cyclin D1 plasmid for 30 hours, the percentage of S＋G2M phase, A490 and the expression rate of PCNA protein in ASMCs were much lower than in untreated cells （P 〈0.01）. （2） The ratios of A490 of cyclin D1 mRNA in CSE group was 0.288±0.034, which was significantly increased compared with that of control group （0.158±0.006） （P 〈0.01）. After the transfection with antisense cyclin D1 plasmid for 30 hours, the ratios of A49o of cyclin D1 mRNA in ASMCs was much lower than in untreated cells （P 〈0.01）. （3） The ratios of A490 of cyclin D1 protein expression in CSE group was 0.375±0.008, which was significantly increased compared with that of control group （0.268±0.004） （P 〈0.01）. After the transfection with antisense cyclin D1 plasmid for 30 hours, the ratios of A490 of cyclin D1 protein expression in ASMCs was much lower than in untreated cells （P 〈0.01）. Conclusion CSE may increase the proliferation of ASMCs in asthmatic rats via regulating cyclin D1 expression.

Clusterin as a serum biomarker candidate contributes to the lung fibroblasts activation in chronic obstructive pulmonary disease

Background:Fibrosis in the peripheral airways contributes to airflow limitation in patients with chronic obstructive pulmonary disease(COPD).However,the key proteins involved in its development are still poorly understood.Thus,we aimed to identify the differentially expressed proteins(DEPs)between smoker patients with and without COPD and elucidate the molecular mechanisms involved by investigating the effects of the identified biomarker candidate on lung fibroblasts.Methods:The potential DEPs were identified by isobaric tags for relative and absolute quantitation(iTRAQ)-based proteomic analysis.The messenger RNA and protein levels of clusterin(CLU)in COPD patients and 12%cigarette smoke extract(CSE)-treated human bronchial epithelial cells were determined at the indicated time points.Furthermore,anin vitro COPD model was established via the administration of 8%CSE to normal human lung fibroblasts(NHLFs)at indicated time points.The effects of CSE treatment andCLU silencing on proliferation and activation of lung fibroblasts were analyzed.Results:A total of 144 DEPs were identified between COPD patients and normal smokers.The iTRAQ-based proteomics and bioinformatics analyses identified CLU as a serum biomarker candidate.We also discovered that CLU levels were significantly increased(P<0.0001)in Global Initiative for Obstructive Lung Disease II,III,and IV patients and correlated(P<0.0001)with forced expiratory volume in 1 s(R=-0.7705),residual volume(RV)(R=0.6281),RV/total lung capacity(R=0.5454),and computerized tomography emphysema(R=0.7878).Similarly,CLU levels were significantly increased in CSE-treated cells at indicated time points(P<0.0001).The CSE treatment significantly inhibited the proliferation,promoted the inflammatory response,differentiation of NHLFs,and collagen matrix deposition,and induced the apoptosis of NHLFs;however,these effects were partially reversed byCLU silencing.Conclusion:Our findings suggest that CLU may play significant roles during airway fibrosis in COPD by regulating lung fibroblast activation.