Animals ; Humans ; STAT6 Transcription Factor ; chemistry ; genetics ; metabolism ; Structure-Activity Relationship

To study the effect of anemoside B4 on rats with chronic obstructive pulmonary disease (COPD).Seventy-two SD male rats were randomly divided into blank group and model group.The method of exposure to cigarette smoke and combined with lipopolysaccharide (LPS) was used to replicate the rat model of COPD.After the model was maintained for 5 weeks,the rats were randomly divided into model group,dexamethasone group (0.81 mg·kg~(-1)) and anemoside B4 low,medium and high (2,4,8 mg·kg~(-1)) dose groups,a group of 12 animals were administered,and then the administration was started.The administration was maintained until the28th day,and the pulmonary function parameters of rats were measured by an animal pulmonary function instrument.After testing the rat lung function parameters,immediately draw rat alveolar lavage fluid (BALF),and use high-throughput protein chip technology to determined the expression levels of inflammatory cytokines in rat BALF.HE staining was used to observe the general pathological changes of rat lung and tracheal tissue.Masson staining was used to observe the collagen deposition in rat lung tissue.Real-time q PCR method was used to determine the mRNA expression level of related genes in rat lung tissue.Western blot method was used to determine the expression levels of related proteins in rat lung tissues.According to the findings,compared with the model group,the dexamethasone group and the anemoside B4 drug groups had different degrees of increase in the lung function parameters of rats (P<0.01,P<0.05),improved the expression level of inflammatory cytokines in the BALF of rats to varying degrees (P<0.01,P<0.05),and improved the pathological structure of rat lung tissue to varying degrees.Relative mRNA expressions of matrix metalloproteinase 2 (MMP-2),matrix metalloproteinase 12 (MMP-12),matrix metalloproteinase inhibitor 1 (TIMP-1),interleukin-6 (IL-6),and transforming growth factor-β1 (TGF-β1) were significantly reduced (P<0.01);whereas relative mRNA expressions of matrix metalloproteinase 9(MMP-9) and matrix metalloproteinase inhibitor 2 (TIMP-2) were increased significantly (P<0.01).The mRNA and protein expression levels of T-box transcription factor (T-bet),interleukin-12 (IL-12) and signal transducer and activator of transcription 4(STAT4) reduced to varying degrees (P<0.01,P<0.05).The mRNA of transcription factor GATA3 (binding protein-3),interleukin-4 (IL-4) and signal transducer and activator of transcription 6 (STAT6) in rat lung tissues and the protein expression levels of IL-4 and STAT6 were increased to varying degrees (P<0.01,P<0.05).In conclusion,anemoside B4 has a certain protective effect on COPD rats caused by cigarette smoke exposure and combined with LPS.The mechanism of action may be related to the regulation of IL-12/STAT4 and IL-4/STAT6 signaling pathways.
Animals ; Interleukin-12 ; Interleukin-4 ; Lung/metabolism* ; Male ; Matrix Metalloproteinase 2 ; Pulmonary Disease, Chronic Obstructive/genetics* ; Rats ; STAT4 Transcription Factor/metabolism* ; STAT6 Transcription Factor/metabolism* ; Saponins

Toxoplasma gondii penetrates all kinds of nucleated eukaryotic cells but modulates host cells differently for its intracellular survival. In a previous study, we found out that serine protease inhibitors B3 and B4 (SERPIN B3/B4 because of their very high homology) were significantly induced in THP-1-derived macrophages infected with T. gondii through activation of STAT6. In this study, to evaluate the effects of the induced SERPIN B3/B4 on the apoptosis of T. gondii-infected THP-1 cells, we designed and tested various small interfering (si-) RNAs of SERPIN B3 or B4 in staurosporine-induced apoptosis of THP-1 cells. Anti-apoptotic characteristics of THP-1 cells after infection with T. gondii disappeared when SERPIN B3/B4 were knock-downed with gene specific si-RNAs transfected into THP-1 cells as detected by the cleaved caspase 3, poly-ADP ribose polymerase and DNA fragmentation. This anti-apoptotic effect was confirmed in SERPIN B3/B4 overexpressed HeLa cells. We also investigated whether inhibition of STAT6 affects the function of SERPIN B3/B4, and vice versa. Inhibition of SERPIN B3/B4 did not influence STAT6 expression but SERPIN B3/B4 expression was inhibited by STAT6 si-RNA transfection, which confirmed that SERPIN B3/B4 was induced under the control of STAT6 activation. These results suggest that T. gondii induces SERPIN B3/B4 expression via STAT6 activation to inhibit the apoptosis of infected THP-1 cells for longer survival of the intracellular parasites themselves.
Animals ; Antigens, Neoplasm/genetics/*metabolism ; *Apoptosis ; Cell Line ; DNA Fragmentation ; Humans ; Macrophages/*cytology/metabolism ; Mice ; Mice, Inbred BALB C ; STAT6 Transcription Factor/genetics/*metabolism ; Serpins/genetics/*metabolism ; Toxoplasma/genetics/*physiology ; Toxoplasmosis/genetics/*metabolism/parasitology/*physiopathology

OBJECTIVETo investigate the effect of interleukin-13 (IL-13) on mucus secretion in vivo and the possible mechanism.

METHODSThe SD rats were randomly divided into control group, IL-13 group and IL-13 plus SP600125 group. The phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal kinase 1/2 (JNK1/2) and the level of MUC5AC in the lung tissues were examined using Western blotting. RT-PCR was performed to examine the mRNA level of STAT4 and STAT6, and electrophoretic mobility shift assays (EMSA) was used to detect the DNA-binding activities of Forkhead box a2 (FOXA2) and activator protein-1 (AP-1).

RESULTSIL-13 caused a significant increase in MUC5AC and p-JNK1/2 expression, but did not affect the phosphorylation of ERK1/2. The expression of MUC5AC was attenuated after treatment with SP600125. A significant increase in STAT6 was observed in IL-13 group compared with that in the control group, whereas the expression of STAT4 mRNA was not significantly affected. The DNA-binding activity of FOXA2 was down-regulated after IL-13 exposure, which did not affect the DNA-binding activity of AP-1.

CONCLUSIONIL-13 down-regulates mucus secretion via STAT6-FOXA2 pathway in vitro.

Animals ; Bronchi ; secretion ; Female ; Hepatocyte Nuclear Factor 3-beta ; genetics ; metabolism ; Interleukin-13 ; pharmacology ; Male ; Mucin 5AC ; metabolism ; Mucus ; secretion ; RNA, Messenger ; genetics ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; STAT6 Transcription Factor ; genetics ; metabolism ; Signal Transduction ; drug effects

Initial skirmishes between the host and pathogen result in spillage of the contents of the bacterial cell. Amongst the spillage, the secondary messenger molecule, cyclic dimeric guanosine monophosphate (c di-GMP), was recently shown to be bound by stimulator of interferon genes (STING). Binding of c di-GMP by STING activates the Tank Binding Kinase (TBK1) mediated signaling cascades that galvanize the body's defenses for elimination of the pathogen. In addition to c di-GMP, STING has also been shown to function in innate immune responses against pathogen associated molecular patterns (PAMPs) originating from the DNA or RNA of pathogens. The pivotal role of STING in host defense is exemplified by the fact that STING(-/-) mice die upon infection by HSV-1. Thus, STING plays an essential role in innate immune responses against pathogens. This opens up an exciting possibility of targeting STING for development of adjuvant therapies to boost the immune defenses against invading microbes. Similarly, STING could be targeted for mitigating the inflammatory responses augmented by the innate immune system. This review summarizes and updates our current understanding of the role of STING in innate immune responses and discusses the future challenges in delineating the mechanism of STING-mediated responses.
Animals ; Cyclic GMP ; physiology ; Dimerization ; Herpes Simplex ; immunology ; pathology ; Humans ; Immunity, Innate ; Membrane Proteins ; chemistry ; genetics ; metabolism ; Protein Binding ; RNA, Viral ; metabolism ; STAT6 Transcription Factor ; metabolism ; Second Messenger Systems

OBJECTIVETo investigate the levels of cytokines related to T-helper (Th) 17 cells in serum and signal transducers in the psoriatic lesions of patients with psoriasis vulgaris of blood-heat syndrome (BHS) and blood-stasis syndrome (BSS).

METHODSSixty patients with psoriasis vulgaris were divided into the BHS and BSS groups according to the syndrome differentiation of Chinese medicine (CM). Ten healthy subjects were considered as the control group. Cytokine levels of interleukin (IL)-17, IL-23 and IL-6 in serum were determined by enzyme-linked immunosorbent assay. Expression levels of signal transducer and activator of transcription 3 (STAT3), p38-mitogen-activated protein kinase (MAPK) and STAT6 in the psoriatic lesions were determined using immunohistochemistry (IHC), Western blot, and real-time quantitative reverse transcription polymerase chain reaction, respectively.

RESULTSProduction of IL-17, IL-23 and IL-6 in the BHS group and BSS group were significantly increased compared with those in the control group (P<0.05). Levels of IL-17 and IL-23 in the BHS group were higher than those in the BSS group (P<0.05). Compared with the control group, IHC positive expressions and protein expressions of STAT3 and p38-MAPK, and the STAT3 mRNA expressions in the BHS and BSS groups were significantly higher (P<0.05 or P<0.01). The protein expression of STAT3 in the BHS group was significantly higher than that in the BSS group (P<0.05).

CONCLUSIONSCytokines in serum and signal transducers in the psoriatic lesions alter with various CM syndromes of psoriasis. The results provide scientific basis for the treatment based on syndrome differentiation of CM in treating psoriasis vulgaris.

Adult ; Female ; Gene Expression Regulation ; Humans ; Immunohistochemistry ; Interleukin-17 ; blood ; Interleukin-23 ; blood ; Interleukin-6 ; blood ; Male ; Psoriasis ; blood ; enzymology ; genetics ; immunology ; RNA, Messenger ; genetics ; metabolism ; STAT3 Transcription Factor ; genetics ; metabolism ; STAT6 Transcription Factor ; genetics ; metabolism ; Signal Transduction ; Syndrome ; Th17 Cells ; immunology ; p38 Mitogen-Activated Protein Kinases ; genetics ; metabolism

OBJECTIVETo investigate the roles of signal transduction and activator of transcription 6 (STAT6) and orosomucoid 1-like 3 (ORMDL3) in airway remodeling among asthmatic mice and to observe the effects of budesonide (BUD) on their expression.

METHODSThirty BALB/c mice were randomly divided into control, asthma, and BUD intervention group. The mice were sensitized and challenged with ovalbumin (OVA) to establish a mouse model of asthma. The BUD intervention group received aerosol inhalation of BUD dissolved in normal saline 30 minutes before each OVA challenge, while normal saline was used instead of OVA solution in the control group. The pathological changes in the airway were observed by hematoxylin-eosin staining and Masson staining. The interleukin-13 (IL-13) level in lung homogenate was measured by enzyme-linked immunosorbent assay. The mRNA expression of STAT6 and ORMDL3 was measured by RT-PCR.

RESULTSThe asthma group showed more pathological changes in the airway than the control and BUD intervention groups, and the BUD intervention group had reduced pathological changes in the airway compared with the asthma group. The asthma and BUD intervention groups had significantly higher IL-13 levels and mRNA expression of STAT6 and ORMDL3 than the control group (P<0.05), and these indices were significantly higher in the asthma group than in the BUD intervention group (P<0.05). The Pearson correlation analysis showed that STAT6 mRNA expression was positively correlated with ORMDL3 mRNA expression (r=0.676, P=0.032).

CONCLUSIONSSTAT6 and ORMDL3 may be involved in the airway remodeling of mice, and BUD can reduce airway remodeling in asthmatic mice, possibly by down-regulating mRNA expression of STAT6 and ORMDL3.

Airway Remodeling ; drug effects ; Animals ; Asthma ; drug therapy ; pathology ; Budesonide ; pharmacology ; Down-Regulation ; Female ; Gene Expression Regulation ; drug effects ; Interleukin-13 ; analysis ; Lung ; metabolism ; Membrane Proteins ; genetics ; Mice ; Mice, Inbred BALB C ; STAT6 Transcription Factor ; genetics

OBJECTIVETo clone and study the polymorphism within interleukin-4 (IL-4) proximal promoter of asthmatic children.

METHODSThe IL-4 proximal promoter segments were amplified and selected by polymerase chain reaction (PCR) and single strand conformation polymorphism (SSCP) with genomic DNA from ten healthy children and forty patients with dominantly allergic familial histories as templates. The selected PCR segments were cloned into recombinant plasmids pIL-4-Jx2. The PCR inserts were sequenced by dideoxy chain termination method.

RESULTSSeven aberrant bands were found in SSCP analysis from forty asthmatic patients. The sequencing results showed that four variant sites were found within or adjacent to the known IL-4 regulatory element. A C to A transversion located at -229 position was just within the positive regulatory element-I (PRE-I) in one patient. A C to T transition adjacent to the negative regulatory element-II (NRE-II) and an extra G adjacent to TATA box were found in two patients. A five base nucleotide deletion was found near signal transducers and activators of transcription-6 responsive element (STAT-6 RE) in one patient.

CONCLUSIONThere were polymorphisms within the IL-4 proximal promoter of allergic asthmatic patients and these polymorphisms might result in aberrant expression of IL-4 gene and asthma.

Asthma ; genetics ; Base Sequence ; Child ; Child, Preschool ; Cloning, Molecular ; Humans ; Interleukin-4 ; genetics ; Molecular Sequence Data ; Plasmids ; Polymerase Chain Reaction ; Polymorphism, Genetic ; Polymorphism, Single-Stranded Conformational ; Promoter Regions, Genetic ; STAT6 Transcription Factor ; Trans-Activators ; metabolism

Scutellarin is a flavonoid extracted from a traditional Chinese herb, Erigeron breviscapus. The present study investigated the effect of scutellarin on MUC5AC mucin production and the possible mechanism. Human bronchial epithelial 16 (HBE16) cells were pretreated with scutellarin for 60 min, and then exposed to human neutrophil elastase (HNE) or interleukin (IL)-13 for 12 hr. RT-PCR and ELISA were performed to measure the amount of MUC5AC mucin production. The results showed that scutellarin inhibited MUC5AC expression both in mRNA and protein level induced by HNE in a concentration-dependent manner. However, scutellarin failed to inhibit MUC5AC mucin production induced by IL-13. To investigate the intracellular mechanisms associated with the effect of scutellarin on MUC5AC mucin production, western blotting was carried out to examine the phosphorylation of protein kinase C (PKC), signal transducer and activator of transcription 6 (STAT6) and extracellular signal-regulated kinase 1/2 (ERK1/2). The phosphorylation of PKC and ERK1/2 was attenuated after treatment with scutellarin, whereas STAT6 was not significantly affected. Therefore, it is suggested that scutellarin down-regulates MUC5AC mucin production on HBE16 cells via ERK-dependent and PKC-dependent pathways.
Apigenin/chemistry/*pharmacology ; Cells, Cultured ; Dose-Response Relationship, Drug ; Down-Regulation ; Epithelial Cells/*drug effects/metabolism ; Erigeron/chemistry ; Glucuronic Acids/chemistry/*pharmacology ; Humans ; Interleukin-13/*pharmacology ; Leukocyte Elastase/*pharmacology ; Mitogen-Activated Protein Kinase 1/metabolism ; Mitogen-Activated Protein Kinase 3/metabolism ; Mucin 5AC/genetics/*metabolism ; Phosphorylation ; Protein Kinase C/metabolism ; Respiratory Mucosa/drug effects/*metabolism ; STAT6 Transcription Factor/metabolism ; Signal Transduction

OBJECTIVETo study the expression of signal transducer and activator of transcription 6 and its mRNA in rat asthma model and the modulatory effect of dexamethasone (DXM).

METHODSThirty male SD rats were randomly divided into three groups: the control group, asthma group and DXM group. The rats in each group were sacrificed 24 h after the last challenge. In the experiment, the rat model of asthma was established by ovalbumin (OVA) challenge method. The lung tissue was taken from the left lung, and bronchoalveolar lavage fluid (BALF) was collected from the right lung. The total cell numbers, eosinophils (EOS) count and differentiated cell counts in BALF were performed on different count fluids. The concentrations of IL-4 in serum and BALF were measured by using sandwich ELISA. The protein expressions of STAT6 were detected with immunohistochemical techniques. The mRNA expressions of STAT6 were detected with in situ hybridization.

RESULTS(1) The total cell counts in BALF, the absolute counts of EOS, and the ratios of eosinophils to the total cell numbers (EOS%) of asthma group were all significantly higher than those of the control group (P < 0.01). The total cell counts in BALF, the absolute counts of EOS, and EOS% of DXM group were all significantly lower than those of asthma group (P < 0.01). (2) The concentrations of IL-4 in BALF and serum of asthma group [(25.7 +/- 7.4) ng/L, (34.2 +/- 10.5) ng/L] were significantly higher than those of control group [(8.6 +/- 3.0) ng/L, (12.1 +/- 2.9) ng/L] (P < 0.01). The concentrations of IL-4 in BALF and serum of DXM group were significantly lower than those of asthma group. (3) Immunohistochemistry showed that the protein content of STAT6 around the bronchus of asthma group (0.171 +/- 0.025) was significantly higher than that of the control group (0.082 +/- 0.022) (P < 0.01), while that of DXM group (0.114 +/- 0.013) was significantly lower than that of asthma group. The epithelial cells were the cells. In situ hybridization showed that the mRNA expression of STAT6 around the bronchus of asthma group (0.180 +/- 0.013) was significantly higher than that of the control group (0.091 +/- 0.012) (P < 0.01), while that of DXM group (0.114 +/- 0.010) was significantly lower than that of asthma group. (4) There was a significant correlation between the concentration of IL-4 in BALF, the content of STAT6 and STAT6 mRNA, respectively, in the epithelial cells of bronchus. There was a significant correlation between the absolute numbers of EOS and EOS% in BALF, the content of STAT6 and STAT6 mRNA, respectively, in the epithelial cells of bronchus.

CONCLUSIONSSTAT6 protein and STAT6 mRNA were found strongly expressed in rat asthma model and the epithelial cells were the chief expressing cells. Dexamethasone had an inhibitory effect on airway inflammatory cells infiltration. It significantly depressed STAT6 and mRNA expression. Which may be a key process in modulatory mechanism of asthma.

Animals ; Anti-Inflammatory Agents ; pharmacology ; Asthma ; drug therapy ; genetics ; metabolism ; Bronchi ; cytology ; Bronchoalveolar Lavage Fluid ; cytology ; Cell Count ; Dexamethasone ; pharmacology ; Disease Models, Animal ; Enzyme-Linked Immunosorbent Assay ; Eosinophils ; drug effects ; Epithelial Cells ; drug effects ; metabolism ; Glucocorticoids ; pharmacology ; Immunohistochemistry ; In Situ Hybridization ; Interleukin-4 ; metabolism ; Male ; RNA, Messenger ; Rats ; Rats, Sprague-Dawley ; STAT6 Transcription Factor ; genetics ; immunology ; metabolism