Expression and pathological significance of CC chemokine receptor 7 and its ligands in the airway of asthmatic rats exposed to cigarette smoke.

BACKGROUND: Cigarette smoking aggravates the symptoms of asthma, leading to the rapid decline of lung function. Dendritic cells (DCs) and lymphocytes are considered initiating and promoting factors for the airway inflammation reactions of asthma. In addition, activation of CC chemokine receptor 7 (CCR7) by chemokine (C-C motif) ligand (CCL) 19 and 21 promotes DCs and T cells migration to lymphoid tissues during inflammation. We aimed to examine how cigarette smoke affects the expression of CCR7 in the lungs of asthmatic rats and explore the signaling mechanism linking CCR7 expression to exacerbation of symptoms. METHODS: Forty Wistar rats were randomized to four groups: control, asthma, smoke exposure, and asthma with smoke exposure groups. A rat asthma model was established by intraperitoneal ovalbumin injection. CCR7 expression was examined with immunohistochemistry and western blotting. The number of airway DCs was determined by OX62 immunohistochemistry. Interferon (INF)-γ, interleukin (IL)-4, CCL19, and CCL21 expression levels in blood and bronchioalveolar lavage fluid (BALF) were determined by enzyme-linked immunosorbent assays (ELISAs). RESULTS: Tissue CCR7 expression, peripheral blood and BALF CCL19 and CCL21 concentrations, and the number of airway DCs were significantly higher in the asthma with smoke exposure group than the asthma group (P<0.01). In addition, INF-γ expression was decreased and IL-4 increased in the asthma and asthma with smoke exposure groups compared with the control group (P<0.01), and in the asthma with smoke exposure group compared with the asthma group (P<0.01). Expression of CCR7 correlated negatively with INF-γ expression in peripheral blood and BALF (P<0.01), and positively with the airway DCs and IL-4 expression in the peripheral blood and BALF (P<0.01). CONCLUSIONS: Cigarette smoking may aggravate asthma symptoms by attenuating immunity, possibly through CCR7-mediated DCs aggregation in lung tissue.

Deficiency of ubiquitin A20 promotes antigen transport across airway epithelial cells via a transcellular pathway.

The epithelial barrier dysfunction is associated with the pathogenesis of a number of diseases. Ubiquitin E3 ligase A20 (A20) plays a critical role in maintaining the homeostasis in the body. This study aimed to investigate the role of A20 in the degradation of endocytic antigens in airway epithelial cells. The expression of A20 in the human nasal epithelial cell line, RPMI 2650 cells (Rpcs), was evaluated. The role of A20 in maintaining the intracellular permeability in Rpc monolayers was assessed in Transwells. The endosome/lysosome fusion in epithelial cells was observed by immunocytochemistry. On the absorption of antigen, the expression of A20 was increased in Rpcs. The knockdown of the A20 gene in Rpcs increased the amounts of the endocytic antigens across the Rpc monolayers. A20 was required in the process of the endosome/lysosome fusion. The antigens transported to the basal compartment by A20-deficient Rpc monolayers still kept strong antigenicity. The nasal epithelial cell line, Rpcs, expresses A20 that facilitates the degradation of endocytic antigens in Rpcs by facilitating the endosome/lysosome fusion.

[Cool/Hot target effect of the water fog infrared stealth].

Artificial spray fog will come into being cool target because of the strong evaporation and convection but weak radiation heat flux, when it is used for defence of infrared imaging guided missile. Also, when it is the contrary condition, the water fog will come into being hot target. In order to open out the phenomenon particularly, a math model which can account for the cool/hot effect produced by water fog shielding the thermal radiation is established by coupling the calculation of radiation transfer equation and energy conversation equation, based on the Mie theory. This model is proved to be accurate in comparison with the Monte-Carlo method and Lambert-Beer' law. The water fog is seemed as absorbing, emitting and anisotropic scattering medium, and the medium radiation, multiple scattering, target radiation flux, and environment influence such as the conductivity, convection turbulent heat diffusion and evaporation is calculated. The phenomenon of cool/hot target effect can be shown in detail with this model.

Expression and significance of myeloid differentiation factor 88 in marrow dendritic cells in asthmatic rats with cigarette smoke exposure.

BACKGROUND: Smoking causes frequent asthma attacks, leading to a rapid decline in lung function in patients with asthma, and it can also reduce the therapeutic effect of glucocorticoids in patients with asthma. Therefore, the present study aimed to investigate the effect of cigarette smoke on the expression of myeloid differentiation factor 88 (MyD88) in marrow dendritic cells (DCs) in asthmatic rats, and to explore the molecular mechanism of cigarette smoke exposure on asthma by DCs. METHODS: Forty Wistar rats were randomly divided into the following groups: control, smoke exposure, asthma, and asthma combined with smoke exposure. The animal model was established, and then rat bone marrow-derived DCs were collected. Additionally, rat spleen lymphocytes and bone marrow-derived DCs were cultured together for mixed lymphocyte responses. Interferon (IFN)-gamma and interleukin (IL)-4, IL-10, and IL-12 expressions were determined by enzyme-linked immunosorbent assay (ELISA). MyD88 expression was determined by Western blotting. The proliferation of lymphocytes was examined with methyl thiazolyl tetrazolium (MTT) colorimetric assay. RESULTS: MyD88 expression was decreased in the asthma combined with smoke exposure group compared to the asthma group (P < 0.01), and IL-10 and IL-12 expressions were decreased in the asthma combined with smoke exposure group compared to control group (P < 0.01). In addition, DCs stimulating activity on allogeneic lymphocytes were significantly decreased in the smoke exposure combined with asthma group compared to the control and asthma groups (P < 0.01). After allogeneic mixed lymphocyte responses, IL-4 expression was increased and IFN-gamma was decreased in the asthma group and the asthma combined with smoke exposure group compared to control group (P < 0.01). IL-4 expression was increased and IFN-gamma was decreased in the asthma combined with smoke exposure group compared to the asthma group (P < 0.01). The study also showed that MyD88 expression was positively correlated with IL-12 and IFN-gamma expressions and the activity of lymphocytes (P < 0.01), and negatively correlated with IL-4 expression (P < 0.01). CONCLUSIONS: Smoking aggravates asthma by weankening immunological mechanism. MyD88-dependent pathways may play a role in the immunological balance and activation of lymphocytes.

Implication of PDGF signaling in cigarette smoke-induced pulmonary arterial hypertension in rat.

Pulmonary artery hypertension (PAH) is a severe disease characterized with progressive increase of pulmonary vascular resistance that finally causes right ventricular failure and premature death. Cigarette smoke (CS) is a major factor of Chronic Obstructive Pulmonary Disease (COPD) that can lead to PAH. However, the mechanism of CS-induced PAH is poorly understood. Mounting evidence supports that pulmonary vascular remodeling play an important role in the development of PAH. PDGF signaling has been demonstrated to be a major mediator of vascular remodeling implicated in PAH. However, the association of PDGF signaling with CS-induced PAH has not been documented. In this study, we investigated CS-induced PAH in rats and the expression of platelet derived growth factor (PDGF) and PDGF receptor (PDGFR) in pulmonary artery. Forty male rats were randomly divided into control group and three experimental groups that were exposed to CS for 1, 2, and 3 months, respectively. CS significantly increased right ventricular systolic pressure (RVSP) and right ventricular hypertrophy index (RVHI). Histology staining demonstrated that CS significantly increased the thickness of pulmonary artery wall and collagen deposition. The expression of PDGF isoform B (PDGF-B) and PDGF receptor beta (PDGFRß) were significantly increased at both protein and mRNA levels in pulmonary artery of rats with CS exposure. Furthermore, Cigarette smoke extract (CSE) significantly increased rat pulmonary artery smooth muscle cell (PASMC) proliferation, which was inhibited by PDGFR inhibitor Imatinib. Thus, our data suggest PDGF signaling is implicated in CS-induced PAH.

Cigarette smoke extract stimulates rat pulmonary artery smooth muscle cell proliferation via PKC-PDGFB signaling.

Accumulating evidence suggests a direct role for cigarette smoke in pulmonary vascular remodeling, which contributes to the development of pulmonary hypertension. However, the molecular mechanisms underlying this process remain poorly understood. Platelet-derived growth factor (PDGF) is a potential mitogen and chemoattractant implicated in several biological processes, including cell survival, proliferation, and migration. In this study, we investigated the effect of cigarette smoke extract (CSE) on cell proliferation of rat pulmonary artery smooth muscle cells (rPASMCs). We found that stimulation of rPASMCs with CSE significantly increased cell proliferation and promoted cell cycle progression from G1 phase to the S and G2 phases. CSE treatment also significantly upregulated the mRNA and protein levels of PDGFB and PDGFRß. Our study also revealed that Rottlerin, an inhibitor of PKCδ signaling, prevented CSE-induced cell proliferation, attenuated the increase of S and G2 phase populations induced by CSE treatment, and downregulated PDGFB and PDGFRß mRNA and protein levels in rPASMCs exposed to CSE. Collectively, our data demonstrated that CSE-induced cell proliferation of rPASMCs involved upregulation of the PKCδ-PDGFB pathway.

[Monte-Carlo algorithm for phase function of medium scattering in radiative heat transfer].

Phase function of the compley distributed systems is the significant parameter in the field of radiative heat transfer in medium. The Monte-Carlo method has the advantages of both numerical algorithm and experiment measurement. Multiple scattering phase function of the complex distributed systems based on the Monte-Carlo method overcomes the former deficiency and expresses the influence of the multiple scattering, also, it can calculate phase functions of any controlled volume. According to a number of mathematical experiments, the larger the density of the medium is the better-proportioned the scattered energy is in the 4 pi solid space.

[Interaction of protein kinase C-extracellular signal-regulated kinase 1/2 signal pathway in the process of plasminogen activator inhibitor-1 expression induced by nicotine in human umbilical vein endothelial cells].

OBJECTIVE: To explore the role of protein kinase C (PKC)- extracellular signal-regulated kinase (ERK)1/2 signal pathway in the process of plasminogen activator inhibitor-1 (PAI-1) protein and mRNA expression in cultured human umbilical vein endothelial cells (HUVECs) induced by nicotine. METHODS: HUVECs were cultured to examine the effect of nicotine on the expression of secreting PAI-1 in HUVECs on different experimental conditions. The expression of PAI-1 protein was measured by ELISA. PKC inhibitor staurosporine (STS) and ERK1/2 inhibitor PD98059 were used to detect PKC or ERK1/2 function on the expression of PAI-1 in HUVECs induced by nicotine. The PAI-1 mRNA expression was determined by RT-PCR. RESULTS: The expression level of PAI-1 protein in 100 µmol/L nicotine treated group [(22.6 ± 1.1) µg/L] increased significantly compared to the control group [(14.2 ± 2.8) µg/L; q = 5.64, P < 0.05]. After stimulation with 100 µmol/L nicotine for 0, 4, 6, 8, 12 and 24 h, the levels of PAI-1 protein increased over time and reached the peak at 12 h (F = 32.063, P < 0.05). The PAI-1 mRNA and protein expression in nicotine treated group [(1.32 ± 0.20), (21.08 ± 0.83) µg/L] increased significantly compared to the control group [(0.73 ± 0.10), (13.39 ± 0.93) µg/L; q = 8.43, 11.97, all P < 0.05].Compared with nicotine treated group, the PAI-1 mRNA and protein expression in nicotine and STS treated group [(1.07 ± 0.10), (16.19 ± 2.15) µg/L] decreased significantly(q = 5.61, 7.61, all P < 0.05), but still higher than the control group (q = 7.84, 4.36, all P < 0.05). In nicotine and PD98059 treated group, the PAI-1 mRNA and protein expression [(1.12 ± 0.11), (17.52 ± 1.72) µg/L] decreased significantly compared to the nicotine treated group(q = 4.68, 5.54, all P < 0.05), still higher than the control group (q = 8.77, 6.43, all P < 0.05). CONCLUSION: PKC-ERK1/2 signal pathway may play a partial role in the up-regulation of PAI-1 induced by nicotine in HUVECs.

Effect of glucocorticoid on MIP-1α and NF-κB expressing in the lung of rats undergoing mechanical ventilation with a high tidal volume.

BACKGROUND: Ventilator induced lung injury (VILI) is a serious complication in the treatment of mechanical ventilating patients, and it is also the main cause that results in exacerbation or death of patients. In this study, we produced VILI models by using glucocorticoid in rats with high tidal volume mechanical ventilation, and observed the content of macrophage inflammatory protein-1α (MIP-1α) in plasma and bronchoalveolar lavage fluid (BALF) and the expression of MIP-1α mRNA and nuclear factor-kappa B (NF-κB) p65 mRNA in the lung so as to explore the role of glucocorticoid in mechanical ventilation. METHODS: Thirty-two healthy Wistar rats were randomly divided into a control group, a ventilator induced lung injury (VILI) group, a dexamethasone (DEX) group and a budesonide (BUD) group. The content of MIP-1α in plasma and BALF was measured with ELISA and the level of MIP-1α mRNA and NF-κBp65 mRNA expressing in the lung of rats were detected by RT-PCR. The data were expressed as mean±SD and were compared between the groups. RESULTS: The content of MIP-1α in plasma and BALF and the level of MIP-1α mRNA and NF-KBp65 mRNA in the lung in the DEX and BUD groups were significantly lower than those in the VILI group (P<0.001). Although the content of MIP-1α in plasma and BALF and the level of MIP-1α mRNA and NF-κBp65 mRNA in the lung in the BUD group were higher than those in the DEX group, there were no significant differences between them (P>0.05). CONCLUSIONS: Glucocorticoid could down-regulate the expression of MIP-1α by inhibiting the activity of NF-κB in the lung and may exert preventive and therapeutic effects on VILI to some extent. The effect of local use of glucocorticoid against VILI is similar to that of systemic use, but there is lesser adverse reaction.

[Study on the correctional method for the attenuation calculation of infrared radiation in the water fogs].

Water fogs system can mightily attenuate the infrared spectrum, so more and more attention has been paid to this problem in military. Based on the Mie theory, the collective characteristic of the particles forward scattering was analyzed. The near forward scattering ratio was defined, also the particle size and scattering DBC case were confirmed when the Lambert-Beer law was applied. A mass of calculation revealed that the visual extinction coefficient calculated with the combined parameter p = x x theta was not accurate, and that the near forward scattering ratio was in direct proportion to both the particle size and scattering angle in the band of middle and far infrared. When the infrared wavelength was fixed, the near forward scattering ratio was in direct proportion to the particle radius. Finally, according to the law of forward scattering, two experiential functions whose variables were not only the p = x x theta were given, by which the correction calculation for light extinction was made easy and exact.

[Effect of cigarette smoke exposure on the percentage of CD(4)(+)CD(25)(+) regulatory T cells and the expression of transcription factor Foxp3 in asthmatic rats].

OBJECTIVE: To investigate the effect of cigarette smoke exposure on the ratio of CD(4)(+)CD(25)(+) regulatory T cells (Treg) and expression of transcription factor Foxp3 in asthmatic rats. METHODS: Forty male Wistar rats were randomly divided into 4 groups (n = 10 for each group): a normal saline group, an aerosolized ovalbumin (OVA) exposure group, a cigarette smoke exposure group and a combined OVA and cigarette smoke exposure group. The rats were exposed to air or cigarette smoke and to normal saline or OVA aerosol for 8 weeks respectively. The percentage of CD(4)(+)CD(25)(+) T cells was determined by flow cytometry analysis. The concentration of interleukin-4 (IL-4) and interferon-γ (INF-γ) in peripheral blood and lung homogenates were measured by enzyme-linked immunosorbent assay (ELISA). The protein expression of Foxp3 in the lung was detected by Western blot. RESULTS: (1) The percentage of CD(4)(+)CD(25)(+) T cells in aerosolized OVA group [(6.4 ± 1.0)%] was significantly lower than that in the normal saline group [(9.9 ± 1.0)%] (P < 0.01). The percentage of CD(4)(+)CD(25)(+) T cells [(3.3 ± 0.8)%] in OVA combined cigarette smoke exposure group was remarkably lower than that in the aerosolized OVA exposure group and in the normal saline group(P < 0.01). (2) IL-4 in both plasma and lung [(22.6 ± 4.3) ng/L, (0.8 ± 0.1) ng/L] was significantly increased in the OVA-exposed rats compared with the normal saline group [(11.4 ± 2.9) ng/L, (0.3 ± 0.1) ng/L] (P < 0.01). Further remarkable increase in IL-4 of both plasma and lung was observed in the group exposed to both OVA and cigarette smoke [(34.1 ± 6.1) ng/L, (1.4 ± 0.3) ng/L] compared with the aerosolized OVA exposure group and the normal saline group (P < 0.05). INF-γ of plasma in OVA-exposed group [(59 ± 20) ng/L] was significantly decreased compared with the normal saline group [(151 ± 56) ng/L] (P < 0.01), and a further remarkable decrease in INF-γ of plasma was observed in the group exposed to both OVA and cigarette smoke [(10 ± 3) ng/L] compared with the aerosolized OVA exposure group and the normal saline group (P < 0.05). (3) Protein expression of Foxp3 in the aerosolized OVA group (8.18 ± 0.26) was lower than that in the normal saline group (10.27 ± 0.33, P < 0.01), while the protein expression of Foxp3 in OVA combined cigarette smoke exposure group (6.36 ± 0.38) was lower than that in the normal saline group and the aerosolized OVA exposure group (P < 0.01). CONCLUSION: The number of CD(4)(+)CD(25)(+) Treg cells and the expression of Foxp3 are likely to be altered by cigarette smoke exposure, which might play an important role in cigarette smoking-induced Th1/Th2 imbalance in asthmatic rats.

[The effect of cigarette smoke on the expression of transforming growth factor-beta1 mRNA and collagen type III in airways of asthmatic rats].

OBJECTIVE: To study the effect of cigarette smoke on the expression of transforming growth factor-beta l (TGF-beta1), and collagen type III in lung tissues, and therefore to investigate the mechanism of airway remodeling. METHODS: Thirty male Wistar rats were randomly divided into a control group, an asthmatic group and a cigarette smoke treated group, with 10 rats in each group. The expression level of TGF-beta1 mRNA was measured by reverse transcription polymerase chain reaction (RT-PCR) and collagen type III by immunohistochemistry. The thickness of airway wall in each group was also measured. Software SPSS 11.0 was used for statistical analysis (data expressed as +/- s). Group comparison was made by one way ANOVA and Pearson correlation was used for correlation analysis. RESULTS: The levels of TGF-beta1 mRNA and collagen type III in cigarette smoke treated group (0.42 +/- 0.04, 25.8 +/- 2.3) were higher than those in the asthmatic group (0.39 +/- 0.04, 22.9 +/- 3.1) and in the control group (0.26 +/- 0.04, 16.3 +/- 2.3). Compared to the control group, the levels were higher in the asthmatic group (F = 55.97, 35.61, all P < 0.05). The level of TGF-beta1 mRNA was positively correlated with the expression of collagen type III (r = 0.71, P < 0.05). The thickness of airway wall in the cigarette smoke treated group (23.3 +/- 2.4) microm2/microm was significantly higher than that in the asthmatic group (20.1 +/- 2.9) microm2/microm and the control group (11.6 +/- 2.4) microm2/microm;compared to the control group, it was higher in the asthmatic group (F = 53.68, P < 0.05). CONCLUSION: Cigarette smoke can promote over-expression of TGF-beta1-mRNA in asthmatic rat airways, increase the expression of collagen type III and aggravate airway remodeling.

[Role of neutrophil activation in ventilator induced lung injury].

OBJECTIVE: To probe further the role of neutrophil activation in the lung injury induced by mechanical ventilation. METHODS: Thirty-two normal Wistar rats were randomly divided into four groups: control group, low tidal volume group, conventional tidal volume group, and high tidal volume group. The counts of white blood cell (WBC) and neutrophil in bronchoalveolar lavage fluid (BALF) were carried out. The levels of protein and myeloperoxidase (MPO) activity in plasma and BALF were determined by biochemical methods respectively. RESULTS: The numbers of WBC and neutrophils, and the levels of protein and MPO activity in BALF were significantly increased in normal and high tidal volume groups than those in control and low tidal volume groups (P<0.05 or P<0.01, respectively). The levels of protein and MPO activity in BALF in high tidal volume group were markedly higher compared with normal tidal volume group (both P<0.01), but no statistical differences existed between the low tidal volume group and the control group (both P>0.05). There were no significant differences in the levels of protein and MPO activity in plasma among the four groups (P>0.05). CONCLUSION: The recruitment and activation of neutrophils might play an important role in pathogenesis of the biotrauma induced by mechanical ventilation. MPO activity in BALF is a credible index in reflecting the activation of neutrophils. Measuring the level of protein in BALF is valuable to evaluate the extent of lung injury induced by mechanical ventilation.

Effects of angiotensin II receptor antagonist on expression of collagen III, collagen V, and transforming growth factor beta1 in the airway walls of sensitized rats.

BACKGROUND: Repeated attacks of bronchial asthma lead to different degrees of airway remodeling, the mechanism of which is not yet clear. Some evidences indicate that it is related to the excessive expression of some growth promotion factors. Angiotensin II is a polypeptide that may be involved in airway remodeling. To evaluate its role in airway remodeling in asthma, we observed the effects of an angiotensin II type 1 receptor antagonist (valsartan) on the expression of collagen III, collagen V, and transforming growth factor beta1 (TGF-beta1) mRNA and protein in the airway walls of sensitized rats. METHODS: Forty Wistar rats were randomly divided into 5 groups: control group, sensitized group, and valsartan groups 1, 2, and 3. The rats in the sensitized group and in valsartan groups 1, 2, and 3 were sensitized and challenged with ovalbumin. Rats in control group were sensitized and challenged with 0.9% NaCl. Rats from valsartan groups 1, 2, and 3 were drenched with valsartan (10 microg, 20 microg, or 30 microg, respectively) at the time of the ovalbumin challenges. The expression of collagen III, collagen V, and TGF-beta1 protein were detected using immunohistochemical method in combination with image analysis methods. The expression of TGF-beta1 mRNA was detected by in situ hybridization. RESULTS: The expression in the airways of collagen III and collagen V was significantly higher in rats from the sensitized group (7.73 +/- 0.81, 1.34 +/- 0.28) and from valsartan groups 1, 2, and 3 (5.73 +/- 0.64, 1.13 +/- 0.15; 4.96 +/- 0.51, 0.98 +/- 0.08; 4.43 +/- 0.35, 0.93 +/- 0.06, respectively) than those in the control group (2.65 +/- 0.38, 0.67 +/- 0.08, P < 0.05). In addition, collagen levels were significantly lower in valsartan groups 1, 2, and 3 than those from the sensitized group (P < 0.05). The expression of TGF-beta1 mRNA and protein in the airways was significantly higher in rats from the sensitized group (20.49% +/- 3.46%, 29.73% +/- 3.25%) and from valsartan groups 1, 2, and 3 (16.47% +/- 1.94%, 19.41% +/- 1.87%; 14.38% +/- 1.58%, 18.29% +/- 1.43%; 12.96% +/- 1.73%, 18.63% +/- 1.11%, respectively) than that from the control group (7.84% +/- 1.61%, 5.63% +/- 1.07%, P < 0.05). TGF-beta1 mRNA and protein levels were significantly lower in valsartan groups 1, 2, and 3 than that in the sensitized group (P < 0.05). CONCLUSIONS: Angiotensin II receptor antagonist valsartan can suppress synthesis of collagen III and collagen V by downregulating TGF-beta1 mRNA and protein expression. Valsartan can decrease airway remodeling and could play a role in asthma therapy.