Regulatory effects of spirolactone on SiO2-induced lung macrophage subtype switching

AIM: To investigate the influence of spirolactone (SPI) on mouse pulmonary macrophage subtype switching induced by silicon dioxide (SiO₂). METHODS: C57BL/6 mice were divided into normal saline (NS) group, SiO₂ group, SiO₂+SPI group and SiO₂+NS group. A mouse model of silicosis was developed with crystalline SiO₂ particles (40 mg/kg, via oropharyngeal instillation). SPI (20 mg/kg) or (NS) was delivered daily by oral gavage after SiO₂ administration. The mice were sacrificed on days 3, 14 and 28. Alveolar washing, total cell counting, differential cell counting and flow cytometry analysis were performed. The right lower lobe of lavaged lungs was collected to prepare single-cell suspension for flow cytometry analysis. RESULTS: Compared with SiO₂ group, SPI treatment significantly alleviated SiO₂-induced inflammatory cell accumulation in brochoalveolar lavage fluid on day 3 and 14. Compared with NS group, the M1 alveolar macrophages and M1 pulmonary interstitial macrophages in SiO₂ group switched to M2 subtype dramatically, while SPI treatment reversed the switching effectively.CONCLUSION: SPI treatment alleviates SiO₂-induced inflammatory cell accumulation, which may be related to reversing macrophage subtype switching.     

Effect of Ginkgo biloba extract on the expression of connective tissue growth factor in the initiating stage of fibrosis in lungs of rats

AIM: To study the effect of Ginkgo biloba extract (GbE) on the expression of connective tissue growth factor (CTGF) in the initiating stage of pulmonary fibrosis of rats after administration of bleomycin (BLM).METHODS: The expression of CTGF in lungs was detected by Western blotting. The content of hydroxyproline was assayed by the method of chloramines T. The content of malondialdehyde (MDA) in plasma was investigated by colorimetry.RESULTS: On day 14 after administration of BLM, the contents of CTGF in lungs and MDA in plasma in BLM+NS group were higher than those in NS group, respectively (P<0.05; P<0.01). On day 30 after BLM, the contents of hydroxyproline in lungs and MDA in plasma in BLM+NS group were higher than those in NS group, respectively (both P<0.01). Treatment with GbE ameliorated the above changes induced by BLM. CONCLUSION: GbE ameliorates the up-regulation of CTGF in the initial stage of fibrosis in lungs of rats after administration of BLM. GbE prevents the hyperoxidative injury in lungs of rats after BLM, which might be one of mechanisms underling the effect of GbE on CTGF.     

Gefitinib prevents bleomycin-induced lung fibrosis in mice

AIM: To evaluate the effect of epidermal growth factor receptor- tyrosine kinase inhibitor (EGFR-TKI) on lung fibrosis induced by bleomycin in mice. METHODS: Forty BALB/c female mice were randomly divided into 4 groups: the mice in control group were given vehicle orally with administering of saline intratracheally; the mice in Ge200 group were given gefitinib (a tyrosine kinase inhibitor) at dose of 200 mg/kg orally with administering of saline intratracheally; the mice in BLM group were given vehicle orally with administering of bleomycin intratracheally; the mice in BLM+Ge20 group was given gefitinib at dose of 20 mg/kg orally with administering of bleomycin intratracheally. All animals were sacrificed by abdominal aortic bleeding 14 days after treatments. The left lung was stained with hematoxylin, eosin and Masson's trichrome respectively for the pathological examination. Total EGFR and phosphorylated EGFR were detected by immunohistochemistry. The tissues of right lung were sampled and the contents of hydroxyproline (HYP) were measured to quantitate the lung fibrosis. RESULTS: Gefitinib prevented lung fibrosis induced by bleomycin with significantly reducing lung collagen accumulation and the level of HYP in BLM+Ge20 group (P<0.05). The phosphorylation of EGFR in lung mesenchymal cells and epithelial cells was inhibited by treating gefitinib after intratracheal administration of bleomycin (P<0.05). Furthermore, in those mice that did not receive bleomycin treatment (Ge200 group), gefitinib neither induced the lung fibrosis nor increased the expression of p-EGFR. CONCLUSION: These findings suggest that, in the preclinical setting, gefitinib has a protective effect on lung fibrosis induced by bleomycin. Gefitinib at high dose (200 mg/kg) dose not induces lung fibrosis.     

Fasudil ameliorates myocardial fibrosis by regulating polarization of macrophages in diabetic mice

AIM: To investigate the effect of hydroxyl fasudil (HF) on myocardial fibrosis and macrophage polarization in the diabetic (D) mice. METHODS: C57BL/6 mice (n=60) were randomly divided into normal saline group (NS group), normal+hydroxyl fasudil group (N+HF group), diabetes group (D+NS group), diabetes+low dose of HF group (D+LHF group), diabetes+middle dose of HF group (D+MHF group) and diabetes+high dose of HF group (D+HHF group). A mouse model of type 1 diabetes mellitus was established by intraperitoneal injection of streptozotocin (STZ). The mice in treatment groups received different doses of fasudil through intraperitoneal injection for 8 weeks. At the end of the study, the effects of fasudil at different doses on the body weight and blood glucose were observed. The histopathological changes of the cardiac tissues were observed by HE staining. The myocardial collagen volume fraction (CVF) was calculated by Masson staining. Immumohistochemical staining was used to test the macrophage polarization and protein expression of interleukin-6 (IL-6), tumor necrosis factor-α(TNF-α) and IL-10 and Western blot was applied to determine the protein levels of p-MYPT1 Thr853, inducible nitric oxide synthase (iNOS) and Arginase-1 (Arg-1).RESULTS: Compared with NS group, the body weight of the mice in D+NS group was decreased and the blood glucose was increased significantly(P<0.05). However, no statistically difference of blood glucose and body weight between the treatment groups and D+NS group was observed. Compared with NS group, CVF, the number of M1-type macrophages and the protein levels of IL-6, TNF-α, p-MYPT1 Thr853 and iNOS were increased markedly, while M2-type macrophages and the expression of IL-10 and Arg-1 were decreased in D+NS group (P<0.05). Compared with D+NS group, CVF, the number of M1-type macrophages, and the protein levels of IL-6 and TNF-α were relatively decreased, conversely the number of M2-type macrophages and the protein level of IL-10 was increased in treatment groups (P<0.05). Moreover, the protein levels of p-MYPT1 Thr853 and iNOS were reduced and the protein level of Arg-1 was increased in D+MHF and D+HHF group compared with D+NS group (P<0.05). No statistical difference in above mentioned indexes between NS group and N+HF group was observed. CONCLUSION: Fasudil significantly attenuates the myocardial fibrosis of diabetic cardiomyopathy in mice, which is possibly related to increased polarization of M2-type macrophages, decreased polarization of M1-type macrophages and inflammation.     

Study on thrombomodulin and von Willebrand factor in microvasculature in mice lungs with pulmonary fibrosis induced by bleomycin

AIM:To explore the distribution of thrombomodulin (TM) and von Willebrand factor (vWf) on endothelial cells of lung microvasculature as well as the phenotype change of this cell in the process of pulmonary fibrosis in C57BL/6 mice. METHODS:It was carried out with dual immunofluorescent stain and quantitative analysis of fluorescent intensity of TM and vWf in normal and pulmonary fibrosis model induced by bleomycin (BLM) administration. RESULTS:① The normal lungs showed multiple continuous linear positive staining of TM and seldom positive of vWf on the surface of endothelium of alveolar capillaries. Meanwhile, blood vessels exhibited considerable positive of vWf in endothelial cell in normal C57BL/6 mice. ② The fibrotic lungs revealed a statistically significant diminution of TM expression, and at the same time, an increase of vWf expression when comparing with normal lung sections.CONCLUSION:These results suggest that TM dominant phenotype endothelial cells, rather than vWf dominant phenotype, are the major ones of alveolar capillaries in normal C57BL/6 mice lungs. TM dominant phenotype endothelial cells changed into vWf dominant ones as pulmonary fibrosis develops. Both TM and vWf antigen might be considered as markers of endothelium injury of lung microvasculature.     

Inhibition of plasminogen activator inhibitor-1 by small interfering RNA attenuates pulmonary fibrosis in rats

AIM: To examine the effects of silencing of plasminogen activator inhibitor-1 (PAI-1) expression by small interfering RNA (siRNA) on bleomycin (BLM)-induced rat pulmonary fibrosis. METHODS: Total 72 Wistar rats were divided into 4 groups: control, BLM, BLM+non-specific siRNA (BLM+N), and BLM+ PAI-1 siRNA (BLM+P). Pulmonary fibrosis was induced by intratracheal injection of BLM (5 mg/kg), whereas equal volume of normal saline was used in control group. After the administration of BLM or normal saline, the rats were treated with tracheal injection of PAI-1-siRNA (7.5 nmol/0.2 mL per rat) in BLM+P group, non-specific siRNA (7.5 nmol/0.2 mL per rat) in BLM+N group, and 0.2 mL normal saline in BLM group and control group, twice a week, 8 times in 28 d. On day 7, 14, and 28, the rats (n=6 at each time point) were sacrificed. The bronchoalveolar lavage fluid (BALF) from the left lung was harvested to examine the activity of PAI-1. The mRNA expression of collagen type Ⅲ, α-smooth muscle actin (α-SMA) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in the middle lobe of the right lung was detected by RT-PCR. RESULTS: PAI-1 activity and the expression of collagen type Ⅲ, α-SMA and TIMP-1 were increased in BLM group on day 7, 14 and 28. Intratracheal injection of PAI-1 siRNA twice a week continuously reduced PAI-1 activity in the BALF (P<0.05),and decreased the expression of collagen type Ⅲ, α-SMA and TIMP-1 in the fibrotic lung tissues on day 7, 14 and 28. Statistical differences in the expression of collagen type Ⅲ, α-SMA and TIMP-1 between BLM+P group and BLM group at the same time point were observed. CONCLUSION: Intratracheal injection of PAI-1 siRNA twice a week continuously inhibits the expression of PAI-1. PAI-1 siRNA ameliorates BLM-induced pulmonary fibrosis by down-regulation of TIMP-1 expression.     

Etanercept attenuates bleomycin-induced lung fibrosis in mice

AIM: To evaluate the effect of tumor necrosis factor α (TNF-α) antagonist etanercept on bleomycin-induced lung fibrosis in mice.METHODS: Forty-five Kunming female mice were randomly divided into 3 groups: the mice in control group were intraperitoneally injected with vehicle and intratracheally administered with saline aerosol, the mice in bleomycin group were intraperitoneally injected with vehicle and intratracheally administered with bleomycin (3 mg/kg) aerosol, and the mice in bleomycin+etanercept group were intraperitoneally injected with etanercept (4 mg/kg) every 3 d and intratracheally administered with bleomycin aerosol. All animals were sacrificed 28 d after treatments. The left lung was fixed in 10% neutral formalin and then stained with hematoxylin-eosin or Masson’s trichrome for the pathological examination. The tissues of right lung were sampled for measuring the content of hydroxyproline (HYP) by the method of alkaline hydrolysis. The serum concentrations of TNF-α and TGF-β were detected by ELISA. Total tissue protein was extracted for examination of ERK1/2, JNK and p38 by Western blotting.RESULTS: Etanercept prevented the collagen accumulation under the airway epithelium and decreased the scores of lung inflammation and fibrosis induced by bleomycin with significantly reduced the levels of tissue HYP, serum TNF-α and serum TGF-β. The protein phosphorylations of ERK/JNK/p38 in the lung tissues were remarkably decreased compared with BLM group.CONCLUSION: Etanercept decreases the phosphorylations of ERK1/2/JNK/p38 via inhibiting the expression of TNF-α and TGF-β. Etanercept might be useful in the treatment of pulmonary fibrosis.     

Role of CD163/TWEAK pathway in atherosclerosis

AIM:To investigate the effect of CD163/tumor necrosis factor-like weak inducer of apoptosis (TWEAK) pathway on atherosclerosis in mice. METHODS:APOE^-/- mice and wild-type (WT) C57BL/6 mice were divided into 4 groups (8~10 weeks, n=10):APOE^-/- +normal diet (ND) group, APOE^-/- +western diet (WD) group, WT+ND group, and WT+WD group. Detection of blood lipid levels and oil red O staining of aorta artery were performed to confirm whether the atherosclerotic model was well established in 16 weeks after feeding. The aortic tissues were harvested to measure CD163 and TWEAK protein levels by Western blot, and immunohistochemical staining was also performed to localize CD163 and TWEAK protein expression on atherosclerotic plaque in each group. The cell experiments were conducted to study whether CD163 regulated TWEAK expression in M1 macrophages and foam cells, and the possible downstream pathway was investigated. RESULTS:The blood lipid levels and aorta oil red O staining showed that the animal model of atherosclerosis was successfully established in APOE^-/- +ND group and APOE^-/- +WD group. The protein level of CD163 was significantly increased in the aortic tissue in APOE^-/- mice (P<0.05) as compared with C57BL/6 mice (P<0.05). Consistently, the protein level of TWEAK was also markedly higher in APOE^-/- +ND group and APOE^-/- +WD group than that in WT+ND group and WT+WD group (P<0.05). Immunohistochemical staining showed that CD163 was mainly expressed in the parts away from the lipid core, and TWEAK was found in all parts of the atherosclerotic plaque. CD163 significantly inhibited the protein expression of TEWAK in the M1 macrophages, and also significantly down-regulated the level of nuclear factor-κΒ (NF-κB) in the M1 macrophages and foam cells (P<0.05). CONCLUSION:The protein levels of CD163 and its ligand TWEAK are significantly increased in atherosclerotic mice. The CD163 positive macrophages are mainly located at the site far away from the lipid core, and CD163 may play an anti-atherosclerotic effect by inhibiting TWEAK/NF-κB pathway.     

Immunological mechanism of long-term stimulation by LPS in macrophages

AIM: To investigate the molecular mechanism and the immunosuppressive phenotype of macrophages under long-term exposure to lipopolysaccharide (LPS). METHODS: We used Ficoll-Hypaque density gradient centri-fugation combined with MicroBeads Separation Kits to separate peripheral blood mononuclear cells from human blood, and then induced the monocytes into macrophages. We observed the morphology of the macrophages by treating the cells with LPS for 48 h, in comparison with a negative control and IFN-γ treatment. ELISA was used to detect the levels of cytokines, such as IL-10, IL-12, IL-6 and TNF-α, and flow cytometry was used to detect the expression of the surface molecules (HLA-DR, CD14, CCR7, HLA-ABC and CD40). To observe the effect of macrophage on T cell proliferation, co-culture experiment was carried out for 6 d. Real-time PCR was used to validate the expression levels of molecules related to MyD88-independent pathway in Toll-like receptor 4 (TLR4) signal pathway. RESULTS: The antigen-presenting ability of the macrophages was reduced and the IL-10 expression level was increased after the cells were treated with LPS for 48 h. We observed a poor proliferative capacity of CD8⁺ T cells after co-culturing of LPS-induced macrophages with CD3⁺ T cells for 6 d. The results of real-time PCR indicated that TRIF, IRF3 and CIITA were down-regulated in LPS-induced macrophages.CONCLUSION: We successfully established a macrophage model in vitro and observed that LPS-induced macrophages into an immunosuppressive phenotype with poor CD8⁺ T cell proliferative capacity, in which MyD88-independent TLR4 signaling pathway was impaired.     

Relationship between airway inflammation and pulmonary arterial remodeling in rats with chronic bronchitis and emphysema

AIM:To study the effects of airway and pulmonary inflammation on pulmonary arterial remodeling in rats with chronic bronchitis (CB) and emphysema.METHODS:Twenty-four male Wistar rats were divided into three groups (n=8): Group A: four-weeks CB and emphysema;Group B: six-weeks CB and emphysema group;Group C: normal control.The rat model of CB and emphysema was established by intratracheal instillation of lipopolysaccharide (LPS) and daily exposure to cigarette smog.The arterial blood gas analysis,pulmonary hemodynamics changes and cell counts in bronchoalveolar lavage fluid (BALF) were measured.The pathomorphological changes of airway inflammation,alveoli destruction and pulmonary arterial remodeling were observed by HE straining and triple straining.RESULTS:(1) The characteristic pathological changes of CB and emphysema were observed in group A and B.Neutrophils were the main cells infiltrated into the walls of airway in group A.Lymphocytes and macrophages were the main cells in group B.(2) Right ventricular systolic pressure (RVSP),mean pulmonary arterial pressure (mPAP),the ratio of the weight of right ventricle/left ventricle and septum (RV/LV+S) in group A and B were significantly higher than those in group C (P<0.05).The amount of muscular artery (MA) in group A and B were significantly higher than that in group C (P<0.05).(3) In group A and B,the levels of MA,RVSP,mPAP and RV/LV+S was correlated positively with the average alveolar area,the total cell counts and differential cell counts of neutrophils,lymphocytes and macrophages in BALF,and the level of infiltration into the walls of airway,respectively (P<0.05).The positive correlation was observed with the percentage of neutrophils,lymphocytes and macrophages between group A and B (P<0.05).The amounts of MA were also correlated positively with RVSP,mPAP and RV/LV+S (P<0.05).CONCLUSIONS:(1) The pulmonary artery hypertension,the right ventricular hypertrophy and the pulmonary arterial remodeling appeared before hypoxia.These may be related with the degree of the pulmonary inflammation.(2) The characteristic of pulmonary arterial remodeling was small artery organization,and correlated positively with the changes of hemodynamics.     

Role of endogenous nitric oxide in apoptosis of alveolar epithelial cells in the development of pulmonary fibrosis in rats

AIM: To study the role of high level of endogenous nitric oxide (NO) in apoptosis of alveolar epithelial cells in the development of pulmonary fibrosis in rats. METHODS: The content of nitrite/nitrate (NO₂^-/NO₃^-) in out-flowing pulmonary blood (OPB) was assayed by nitric acid reduction method. The apoptosis of alveolar epithelial cells was observed by TdT-mediated dUTP nick-end labeling (TUNEL) and electron microscopy, respectively. The above indices were observed on the day 14 and the day 30 after intratracheal administration of BLMA₅ alone or along with blockade of iNOS by aminoguanidine (AG) in rats. RESULTS: (1) Both the content of NO₂^-/NO₃^- in OPB and the number of apoptotic alveolar epithelial cells in lung were increased in BLMA₅ 14 d group, compared with normal control group and BLMA₅ 30 d group, respectively (P<0.05). The high level of NO₂^-/NO₃^- in OPB and the apoptosis of alveolar epithelial cells were ameliorated by AG. CONCLUSION: The apoptosis of alveolar epithelial cell is induced by high level of endogenous NO in the development of pulmonary fibrosis.     

Effect of granulocyte colony-stimulating-factor on acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation in a murine model

AIM: To explore the impact of granulocyte colony-stimulating factor (G-CSF) on acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in a murine model and its possible mechanisms. METHODS: Male C57BL/6 (H-2^b) and BALB/c (H-2^d) mice were used as the allogeneic and syngeneic donor mice, respectively. Moreover, female BALB/c mice were used as recipient mice. The recipient mice were conditioned by a single dose (8 Gy) of total body irradiation (TBI). The recipient mice were randomly divided into 7 groups: TBI group, Syn-BMST control group, post-Syn-BMST G-CSF administration (Syn-BMST+G-CSF)group, allo-BMT control group, post-allo-BMT G-CSF administration (allo-BMT+G-CSF)group, allo-BMST control group and post-allo-BMST G-CSF administration (allo-BMST+G-CSF) group. The mice in control groups and G-CSF administration groups were subcutaneous injected with 0.1 mL normal saline (NS) and 0.1 mL NS containing 2 μg G-CSF per day from 1st day, respectively. The effect of G-CSF on aGVHD was evaluated by clinical manifestations and pathological changes, as well as survival time of the mice in different groups. The serum levels of IL-2, IL-4, IFN-γ and TNF-α in allo-BMST and allo-BMST+G-CSF groups were detected by ELISA at 10th day. Flow cytometry was used to analyze the immunophenotypes of splenocytes at 10th day. RESULTS: The mice in TBI group were all died for hematologic failure on 9~15 d after TBI. No effect of G-CSF on the survival of the mice underwent Syn-BMST and transplantation of single allogeneic marrow cells was observed. The mean survival days in allo-BMST group and allo-BMST+G-CSF group were (34.8±4.5) d and (19.8±6.1) d'respectively (P<0.01). Moreover, post-transplant administration of G-CSF increased the spleen total nucleated cells count (SpTNC), NK cells subset, and DC1/DC2 ratio in the spleen with over 99% of donor chimerism rate at 10th day. No difference in the levels of serum IL-2, IL-4, IFN-γ and TNF-α between the 2 group at 10th day was found. CONCLUSION: The administration of G-CSF after allo-BMST significantly aggravates mouse aGVHD. The expansion of NK cells stimulated by G-CSF may be involved in the mechanism of generating alloreactivity against host cells. These results imply there may be potential risk of evoking or aggravating acute GVHD if G-CSF is administered in the early stage of clinical allo-HSCT.     

Relationship between invasion of tumor-associated macrophages and phenotype and immune efficacy of tumor-infiltrating lymphocytes in advanced ovarian carcinoma

AIM:To explore the relationship between the invasion of tumor-associated macrophages(TAM) and the phenotype and immune efficacy of tumor-infiltrating lymphocytes(TIL) in advanced ovarian carcinoma. METHODS:Immunohistochemical analysis of TAM density in 175 cases of poorly-differentiated ovarian cancer tissue biopsy was performed. The cases were divided into TAM high-density(TAM^High) group and TAM low-density(TAM^Low) group according to the median of TAM density. The control group included 32 cases of benign ovarian lesions. The changes of CD8⁺ and CD25⁺ phenotypes of TIL were detected by flow cytometry analysis. TIL in the 2 groups were cultured in vitro and the conditioned-medium was collected for detecting the expression of IL-2, IL-10, TGF-β and IFN-γ by ELISA. RESULTS:The average TAM infiltration density was 62.8/high-power field(HP, ×400) in 175 cases of poorly-differentiated ovarian carcinoma, and the median was 53.3/HP. TAM^High group was 87 cases and TAM^Low group was 88 cases. A significant difference between malignant ovarian carcinoma group and control group(10.5/HP) was observed. The mean expression of CD8⁺ TIL in TAM^High group was 24%, and CD8⁺ TIL in TAM^Low group was 52%(P<0.05). The mean expression of CD25⁺ TIL in TAM^High was 48%, and CD25⁺ TIL in TAM^Low was 25%(P<0.05). The average infiltration density of CD8⁺ and CD25⁺ TIL in control group was 7%. The average infiltration density of CD8⁺ and CD25⁺ TIL in TAM^High and TAM^Low groups was significantly higher than that in control group(P<0.05). Compared with TAM^Low group, TIL destruction cytokines IL-2 and IFN-γ were significantly decreased in TAM^High group(P<0.05), while the inhibitory cytokines IL-10 and TGF-β were significantly increased(P<0.05). CONCLUSION:In high-density TAM infiltration of ovarian cancer tissues, CD25⁺ TIL type and inhibitory cytokines IL-10 and TGF-β increase, while CD8⁺ TIL type and destruction cytokines IL-2/IFN-γ decrease, suggesting that the high-density TAM has relationship with the phenotype and immune efficacy of TIL.     

VPA alleviates bleomycin-induced pulmonary fibrosis in rats

AIM: To investigate the effect of sodium valproate (VPA) on bleomycin-induced pulmonary fibrosis (PF) and its mechanism. METHODS: SD rats (n=42) were randomly divided into model group and treatment group. Bleomycin at dose of 5 mg/kg was intratracheally injected to establish a rat PF model. The rats in treatment group were given normal saline (NS, 0.5 mL/d), VPA (300 mg·kg^-1·d^-1) or dexamethasone (DEX, 0.6 mg·kg^-1·d^-1) via intraperitoneal injection from the 14th day to the 28th day after modeling. The rats in model group were sacrificed on 0 d, 14 day and 28 d after modeling . The rats in treatment group were killed at 14th day after treatment. The effects of VPA on PF were evaluated by HE and Masson staining. The hydroxyproline (HYP) content in the rat lung tissues was detected, and the expression of α-smooth muscle actin (α-SMA) and E-cadherin was determined by Western blotting. RESULTS: HE staining showed that the alveolar structure and interstitial morphology in VPA group were better than those in NS group and DEX group. The level of collagen in VPA group was significantly lower than that in DEX group and NS group by determining the HYP content and Masson staining. VPA reduced the expression of α-SMA, a mesenchymal marker protein of PF, while increased the expression of epithelial marker protein E-cadherin. CONCLUSION: VPA reduces collagen content and distribution, and up-regulates the expression of the epithelial marker protein E-cadherin, while down-regulates mesenchymal marker protein α-SMA, thereby preventing the rat lung tissues from bleomycin-induced PF.     

Effect of ghrelin on iNOS expression in alveolar macrophages and lung tissues in rats with sepsis-associated lung injury

AIM: To investigate the effect of ghrelin on inducible nitric oxide synthase (iNOS) expression in alveolar macrophages and lung tissues in sepsis-induced acute lung injury (ALI) rats. METHODS: The septic rat model was established by cecal ligation and puncture (CLP). Male SD rats were divided into sham group, CLP group and CLP+ghrelin group. The rats in the former 2 groups were further divided into 3 subgroups, which were 6 h, 12 h and 20 h post-operation groups. Ghrelin was administered by intraperitoneal injection at 3 h and 15 h after operation in ghrelin group. The samples were harvested 20 h after operation. The mRNA expression of iNOS in alveolar macrophages collected from bronchoalveolar lavage was detected by RT-PCR. The protein levels of lung iNOS were measured by Western blotting. The lung pathological examination was performed 20 h after operation. RESULTS: In CLP group, the mRNA expression levels of iNOS in the alveolar macrophages were 1.33±0.05, 1.44±0.08, 1.57±0.11 at 6 h, 12 h and 20 h after CLP, respectively, which were higher than that in sham group, but did not show time correlation. However, it was lower in CLP group than that in CLP+ghrelin group at 20 h after CLP (2.27±0.37, P<0.05). At 20 h after CLP, the protein level of lung iNOS was decreased in CLP+ghrelin group (0.87± 0.03) as compared with CLP group (1.08±0.05). Compared with sham group, the histopathological score was increased in both CLP group and CLP+ghrelin group, but it was lower in CLP+ghrelin group (5.83±0.477) than that in CLP group (7.83±0.75). CONCLUSION: Ghrelin treatment improves the degree of ALI. During 6 h to 20 h after CLP, the mRNA expression of iNOS in alveolar macrophages was elevated, but the difference was not seen as the time went on. Ghrelin up-regulates the mRNA expression of iNOS in alveolar macrophages and inhibits iNOS expression in lungs of septic rats.     

Regulation of LPS-induced elevation of Ca2+ intracellular level of alveolarmacrophages in chronic bronchitis by Angelica Sinensis and nifedipine

AIM: To explore regulation of lipopolysaccharide (LPS)-induced elevation of Ca²⁺ intracellular level in alveolar macrophages(AMs) from patients with chronic bronchitis by Angelica Sinensis and nifedipine.METHODS:AMs was obtained from 7 patients with chronic bronchitis and 6 normal controls by bronchoalveolar lavage and intracellular Calevel was detected after adding Angelica Sinensis, nifedipine or LPS to the supernatant of AMs loaded by Fura-2. RESULTS: In contrast with normal control group (99.65±32.21 nmol/L), intracellular Ca²⁺ level in AMs from chronic bronchitis group (189.47±23.69 nmol/L) was increased significantly in the absence of extracellular Ca²⁺ but not 1 mmol/L. Intracellular Ca²⁺ level in AMs from chronic bronchitis group were significantly increased by adding 10 μg/mL LPS to the supernatant of AMs. LPS-induced elevation of intracellular Ca²⁺ level in AMs from chronic bronchitis group was completely inhibited by Angelica Sinensis or nifedipine.CONCLUSION: Both Anelica Sinensis and nifedipine may inhibit activation of AMs from patients with chronic bronchitis by reducing LPS-induced elevation of intracellular Ca²⁺ level in AMs, suggested that these two medicines may inhibit non-specific inflammation of airways in chronic bronchitis.     

Effects of FGF-21 and Nrf2 on BLM-induced pulmonary fibrosis in mice

AIM:To investigate the effect of fibroblast growth factor-21 (FGF-21) on bleomycin (BLM)-induced inflammatory response and oxidative stress in the lung, and to further explore the molecular mechanism of FGF-21 against pulmonary fibrosis. METHODS:The lung fibrosis model was induced by BLM intratracheal instillation. A total of 40 mice were randomly divided into control group, BLM group, FGF-21 (1, 2 and 5 mg/kg)+BLM groups. Western blot was used to detected the protein expression of collagen I, fibronectin and nuclear factor E2-related factor 2 (Nrf2). The reactive oxygen species (ROS) production was measured by DCFH-DA staining. The levels of inflammatory cytokines were measured by ELISA. The content of malondialdehyde (MDA), the activity of superoxide dismutase (SOD) and glutathione peroxidase (GPx), and the content of hydroxyproline (HYP) were detected by commercially available assay kits. RESULTS:Treatment with FGF-21 notably attenuated BLM-induced the expression levels of inflammatory mediators tumor necrosis factor-α, interleukin-1β and interleukin-6 in the lung tissue. In addition, FGF-21 treatment remarkably reduced the generation of ROS and the content of MDA trigged by BLM, accompanied with the enhanced activity of anti-oxidative enzymes SOD and GPx (P<0.05). Furthermore, treatment with FGF-21 obviously reduced the extracellular matrix (ECM) accumulation by suppressing the expression of collagen I and fibronectin induced by BLM, accompanied with the decreases in the levels of TGF-β1 and HYP. Silencing of Nrf2 expression abolished the protective effect of FGF-21. CONCLUSION:FGF-21 relieves BLM-induced pulmonary fibrosis by reducing the inflammatory response, mitigating oxidative damage and decreasing the ECM deposition via Nrf2 activation, thus providing the basis for the therapeutic effect of FGF-21 on the lung fibrosis.     

IgE-FcεRI crosslink accelerates atherosclerosis development in allergic asthmatic mice

AIM:To investigate whether allergic asthma accelerates the development of atherosclerosis in mice related to Th2 cells and interleukin-4 (IL-4), and the roles of activation of macrophages by immunoglobulin E (IgE)-Fc ε receptor I (FcεRI) crosslink during the process. METHODS:Six-week-old ApoE^-/- mice were sensitized and challenged by ovalbumin to establish the allergic asthma model, and then assigned to 3 groups:control group, asthmatic placebo group and asthmatic IL-4 monoclonal antibody (mAb) intervention group (intervention for 8 weeks). The lesion area was measured by oil red O staining. The percentages of Th2 cells in the splenocytes of the mice were analyzed by flow cytometry. The mRNA expression of IL-4 and the macrophage-related inflammatory factors, monocyte chemotactic protein 1 (MCP-1), macrophage inflammatory protein-1α (MIP-1α) and IL-6, in the spleen was detected by real-time PCR. Local IgE and FcεRIα expression in the plaque was evaluated by immunofluorescence/immunohistochemical staining, and the circulating IL-4 and IgE were measured by ELISA. RESULTS:Accompanied by aggravated atherogenesis in asthmatic ApoE^-/- mice, the proportion of Th2 cells and IL-4 mRNA in the spleen, IgE and FcεRIα expression in the aortic root, and the mRNA expression of MCP-1, MIP-1α and IL-6 were markedly increased. After 8-week treatment with IL-4 mAb, the lesion area in the aortic root of asthmatic ApoE^-/- mice was markedly decreased, the elevated IgE and FcεRIα expression was significantly decreased, and the mRNA expression of macrophage-related inflammatory factors was also decreased. CONCLUSION:Allergic asthma accelerates the atherosclerosis in ApoE^-/- mice, which is associated with the increased Th2 cells and IL-4, and the activation of macrophages by IgE-FcεRI crosslink.     

Effects of sevoflurane preconditioning on myocardial dysfunction in lipopolysaccharide-challenged mice

AIM:To investigate the effects of sevoflurane(Sevo) preconditioning on myocardial dysfunction in lipopolysaccharide(LPS)-challenged mice. METHODS:Forty male BALB/c mice were randomly allocated to 4 groups:control group, LPS group, Sevo+LPS group and Sevo group. Following pretreatment with or without 2% Sevo for 30 min and washing out for 10 min, all mice received intraperitoneal injection of LPS or normal saline(NS). The mice received an echocardiographic evaluation by a high-resolution in vivo imaging system 12 h after administration of LPS or NS. The mice were then killed and the hearts were removed for histological analysis. Serum levels of lactic dehydrogenase(LDH), creatine kinase-MB(CK-MB) were measured with an automatic biochemical analyzer. The myocardium was homogenized for detecting the activity of inducible nitric oxide synthase(iNOS) and the content of nitric oxide(NO). RESULTS:Echocardiographic evaluation demonstrated that LPS resulted in an increase in lert ventricular end-diastolic volume and significant decreases in stroke volume,cardiac output and ejection fraction. The alteration of cardiac functions was inhibited by the pretreatment with Sevo. LPS caused significant elevation of LDH and CK-MB in serum samples and severe pathological damage of the hearts. Compared with LPS group, serum levels of LDH and CK-MB were reduced and pathological damage was attenuated in Sevo+LPS group. Sevo preconditioning also significantly attenuated the increases in iNOS and NO induced by LPS. CONCLUSION:Sevo preconditioning protects against myocardial impairment and myocardial dysfunction in LPS-challenged mice. Inhibition of iNOS activity and of NO production by Sevo preconditioning may contribute to the beneficial role in the process of cardioprotection during endotoxemia.     

Chinese herbal preparation Qing Yi Tang Ⅱ granule protects against experimental acute pancreatitis in mice

AIM: To investigate the protect effect of Chinese herbal preparation, Qing Yi TangⅡgranule (QYT), on acute pancreatitis (AP) mice and its mechanism. METHODS: Adult male and female C57BL/6 mice (n=24) were randomly divided into control group, AP group and AP+QYT group. Severe AP was induced by combined intra-peritoneal injection of caerulein (50 μg/kg) and lipopolysaccharide (LPS; 10 mg/kg). Drinking water or 24% QYT solution was given to the mice in AP group or AP+QYT group by oral gavage. The mice in control group were intraperitoneally injected with equivalent volume of normal saline and gavaged with water. The mice were sacrificed 3 h after the last injection. Severity of AP was assessed by biochemical markers and histology. The plasma level of IL-6 and MCP-1, and lung myeloperoxidase (MPO) levels were determined for assessing the extent of systemic inflammatory response. The intestinal microflora, T lymphocytes and T-lymphocyte subgroups were examined for assessing the function of the intestinal barrier. RESULTS: Compared with control group, the mice in AP group presented significant increases in pathological histological scores, plasma amylase activity and IL-6 and MCP-1 levels, as well as the MPO activity in the lung and pancreatic tissues. QYT attenuated these changes to some extent. Furthermore, the increased intestinal microflora was significantly reversed by QYT. No difference of the numbers of Peyer's patches in small intestine in the 3 groups was observed, but the percentage of CD3⁺ T lymphocytes decreased significantly in AP group, and increased percentage of CD4⁺ and CD4⁺/CD8⁺ ratio were found in AP group and AP+QYT group. CONCLUSION: QYT protects against cearulein and LPS-induced acute pancreatitis in mice. The mechanisms may be related to the suppression of the inflammatory response, promoting intestinal bacteria removal, and regulating the functions of T lymphocytes in the intestinal barrier.