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

AIMTo study the effect of achyranthes bidentata polysaccharides(ABPS) on the expression of signal transducer and activator of transcription 6 and its mRNA in bronchus of a rat model of asthma.

METHODSThirty male SD rats were randomly divided into three groups: the control group, asthma group and ABPS group. The total cell numbers, eosinophils (EOS) numbers and differentiated cell numbers in bronchoalveolar lavage fluid (BALF) were counted by different count fluids. The concentrations of IL-4 in serum and BALF were measured by sandwich ELISA. The protein expressions of STAT6 were detected by immunohistochemistry techniques. The mRNA expressions of STAT6 were detected by hybridization in situ.

RESULTS(1) The total cell numbers in BALF, the absolute numbers of EOS, 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 numbers in BALF, the absolute numbers of EOS and EOS% of ABPS 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 were significantly higher than those of control group (P < 0.01), while the concentrations of IL-4 in BALF and serum of ABPS group were significantly lower than those of asthma group. (3) Immunohistochemistry showed that the protein content of STAT6 around the bronchus of asthma group was significantly higher than that of the control group (P < 0.01), while that of ABPS group was significantly lower than that of asthma group , the epithelial cells were the chief expression cells; hybridization in situ showed that the mRNA expression of STAT6 around the bronchus of asthma group was significantly higher than that of the control group (P < 0.01), while that of ABPS group was significantly lower than that of asthma group , the epithelial cells were the chief expression cells.

CONCLUSIONSTAT6 protein and STAT6 mRNA were found strongly expressed in rat asthma model, the epithelial cells were the chief expression cells. ABPS had an inhibitory effect on airway inflammation cells infiltration such as EOS, it significantly depressed STAT6 and its mRNA expression, thus reduced the synthesis of IL-4 might be key in modulating mechanism of asthma.

Achyranthes ; Animals ; Asthma ; metabolism ; Eosinophils ; metabolism ; Interleukin-4 ; metabolism ; Male ; Polysaccharides ; pharmacology ; RNA, Messenger ; metabolism ; Rats ; Rats, Sprague-Dawley ; STAT6 Transcription Factor ; metabolism ; Signal Transduction

OBJECTIVE: To investigate the relation between IL-4/STAT6 and allergic rhinitis by comparing expressions of IL-4 and STAT6 in normal nasal mucosa and allergic rhinitis models, to explore the influence of glucocorticoid on IL-4, and STAT6 expression, and then to elucidate further the pathogenesis of AR and the mechanism of glucocorticoid. METHOD: Forty-five guinea pigs were divided into three groups: normal control (NC) group, allergic rhinitis group (AR) and glucocorticoid (Glu) group (15 each). Animals in AR and Glu groups were sensitized with egg albumin, and in NC group were treated with normal saline as control. After sensitization and reproduction of AR model, rats in AR group received no treatment, while those in Glu group were treated with glucocorticoid (50 microl/one side/time, once a day) for 5 days. The changes in behavior was examined, and pathology of nasal mucosa were observed with HE staining, and the protein expressions of IL-4 and STAT6 in the nasal mucosa were detected by immunohistochemical technique. RESULT: Compared with NC group, the frequency of sneezing and nose-scratching, and the expressions of IL-4 and STAT6 were increased obviously, but the opposite findings were observed in Glu group. CONCLUSION IL-4 and STAT6 are related to the pathogenesis of allergic rhinitis and may be the main factors for eosinophil infiltration in allergic rhinitis. Glucocorticoid may produce a therapeutic effect by intervening the expression of IL-4 and STAT6.
Animals ; Disease Models, Animal ; Glucocorticoids ; pharmacology ; Guinea Pigs ; Interleukin-4 ; metabolism ; Male ; Nasal Mucosa ; drug effects ; metabolism ; pathology ; Rhinitis, Allergic, Perennial ; metabolism ; pathology ; STAT6 Transcription Factor ; metabolism

Obesity results in an inflammatory microenvironment in adipose tissue, leading to the deterioration of tissue protective mechanisms. Although recent studies suggested the importance of type 2 immunity in an anti-inflammatory microenvironment in adipose tissue, the regulatory effects of T helper 2 (Th2) cytokines on systemic metabolic regulation are not fully understood. Recently, we identified the roles of the Th2 cytokine (interleukin 4 [IL-4] and IL-13)-induced adipokine, growth differentiation factor 15 (GDF15), in adipose tissue in regulating systemic glucose metabolism via signal transducer and activator of transcription 6 (STAT6) activation. Moreover, we showed that mitochondrial oxidative phosphorylation is required to maintain these macrophage-regulating autocrine and paracrine signaling pathways via Th2 cytokine-induced secretion of GDF15. In this review, we discuss how the type 2 immune response and Th2 cytokines regulate metabolism in adipose tissue. Specifically, we review the systemic regulatory roles of Th2 cytokines in metabolic disease and the role of mitochondria in maintenance of type 2 responses in adipose tissue homeostasis.
Adipokines ; Adipose Tissue ; Cytokines ; Glucose ; Growth Differentiation Factor 15 ; Homeostasis ; Metabolic Diseases ; Metabolism ; Mitochondria ; Obesity ; Oxidative Phosphorylation ; Paracrine Communication ; STAT6 Transcription Factor

OBJECTIVE: To study the distribution and expression of STAT6 and to examine the suggested roles of STAT6 in the pathogenesis of eosinophil infiltration in nasal polyps and to evaluate the role of STAT6 in the pathogenesis of nasal polyps. METHOD: All selected cases met the enrollment criteria. Thirty samples of nasal polyps were obtained from patients undergoing nasal polypectomy, and 10 samples of inferior turbinate tissues were from patients undergoing nasal septal reconstruction. STAT6 in nasal polyp tissues from 30 nasal polyposis patients and 10 samples of inferior turbinate tissues were detected with immunohistochemistry (SP) method. SPSS13.0 system was used to perform the statistical analysis. RESULT: The positive expression of STAT6 was significantly higher in epithelium of nasal polyps than that of the control. The number of eosinophils was significantly higher in epithelium of nasal polyps than that of the control. The difference between these two groups was statistically significant (P<0.05). STAT6 positive cell were localized on epithelium, gland cells and on inflammatory cell of nasal polyps. STAT6 expression was positively correlated with the recruitment of eosinophils in nasal polyps. CONCLUSION The high expression of STAT6 protein and the suggested roles of STAT6 in the recruitment of eosinophils in nasal polyps may contribute to the initiation and progression of nasal polyps.
Adolescent ; Adult ; Aged ; Eosinophils ; pathology ; Female ; Humans ; Inflammation ; Male ; Middle Aged ; Nasal Polyps ; metabolism ; pathology ; STAT6 Transcription Factor ; metabolism ; Young Adult

Toxoplasma gondii provokes rapid and sustained nuclear translocation of the signal transducer and activator of transcription 6 (STAT6) in HeLa cells. We observed activation of STAT6 as early as 2 hr after infection with T. gondii by the nuclear translocation of fluorescence expressed from exogenously transfected pDsRed2-STAT6 plasmid and by the detection of phosphotyrosine-STAT6 in Western blot. STAT6 activation occurred only by infection with live tachyzoites but not by co-culture with killed tachyzoites or soluble T. gondii extracts. STAT6 phosphorylation was inhibited by small interfering RNA of STAT6 (siSTAT6). In view of the fact that STAT6 is a central mediator of IL-4 induced gene expression, activation of STAT6 by T. gondii infection resembles that infected host cells has been stimulated by IL-4 treatment. STAT1 was affected to increase the transcription and expression by the treatment of siSTAT6. STAT6 activation was not affected by any excess SOCS's whereas that with IL-4 was inhibited by SOCS-1 and SOCS-3. T. gondii infection induced Eotaxin-3 gene expression which was reduced by IFN-gamma. These results demonstrate that T. gondii exploits host STAT6 to take away various harmful reactions by IFN-gamma. This shows, for the first time, IL-4-like action by T. gondii infection modulates microbicidal action by IFN-gamma in infected cells.
Active Transport, Cell Nucleus ; Animals ; Chemokines, CC/biosynthesis ; Hela Cells ; Humans ; Interleukin-4/*immunology ; Mice ; Mice, Inbred BALB C ; STAT6 Transcription Factor/*immunology/*metabolism ; Toxoplasma/*immunology

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

The study was aimed to explore the effects of T-bet (T-box expressed in T cell), GATA-3(GATA binding protein 3) and relevant signal transduction pathways on the immune-related pathogenesis of chronic aplastic anemia (CAA), and to investigate the immunological regulation mechanism in the treatment of CAA by using cyclosporine A (CsA) at the level of Th cell imbalance, transcriptional factors, and relevant signal pathways. The real-time fluorescent quantitative polymerase chain reaction (real-time FQ-PCR) was used to determine the mRNA expression of T-bet, GATA-3, signal transducers and activators of transcription 4 (STAT4) and signal transducers and activators of transcription 6 (STAT6) in peripheral blood mononuclear cell (PBMNC) of CAA patients before and after treatment with CsA; the flow cytometry (FCM) and enzyme linked immunosorbent assay (ELISA) were used to determine the Th1/Th2 proportion in peripheral blood, and levels of IFN-γ, IL-12 and IL-4 in PBMNC-cultured supernatant. Healthy people were included to test the above indexes. The results showed that the mRNA expression of PBMNC T-bet, STAT4, T-bet/GATA-3 ratio, Th1 proportion, Th1/Th2 ratio and levels of IFN-γ and IL-12 in PBMNC-cultured supernatant of CAA patients were significantly higher than those of healthy people (p < 0.01). After treating with CsA for 6 months of CsA treatment, expression of T-bet, STAT4, T-bet/GATA-3 ratio, Th1 proportion, IFN-γ and IL-12 levels were lower than before, however, the expression of T-bet, STAT4, T-bet/GATA-3 ratio, Th1 proportion and IFN-γ had not been reduced to normal state. Compared to healthy people, no significant difference existed in the mRNA expression of GATA-3, STAT6, Th2 proportion, as well as level of IL-4 before and after treatment (p>0.05). It is concluded that the abnormal activation of IFN-γ/T-bet and IL-12/STAT4 pathways, as well as Th balance deviating to Th1 excursion play vital roles in the immunological pathogenesis of AA. CsA lowers the abnormal activation of IFN-γ/T-bet and IL-12/STAT4 pathways to correct Th1 hyperpolarization, which may reduce the abnormally activated cell-mediated immunity and relax hematopoietic depression of AA patients.
Adolescent ; Adult ; Aged ; Anemia, Aplastic ; drug therapy ; immunology ; metabolism ; Case-Control Studies ; Cyclosporine ; pharmacology ; Female ; GATA3 Transcription Factor ; metabolism ; Humans ; Interferon-gamma ; metabolism ; Interleukin-12 ; metabolism ; Interleukin-4 ; metabolism ; Male ; Middle Aged ; STAT4 Transcription Factor ; metabolism ; STAT6 Transcription Factor ; metabolism ; Signal Transduction ; T-Box Domain Proteins ; metabolism ; Th1 Cells ; drug effects ; Th2 Cells ; drug effects ; Young Adult

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