Study on effect of anemoside B4 in improving COPD rats by regulating IL-12/STAT4 and IL-4/STAT6 signaling pathways / 中国中药杂志

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.

The effect of suppressive oligodeoxynucleotides on interferon-γ and phosphorylation of signal transducers and activators of transcription 4 expression of silica-induced pulmonary inflammation in mice / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the protective effect of suppressive oligodeoxynucleotides (Sup ODN) on interferon-γ (IFN-γ) and signal transducers and activators of transcription (pSTAT4) expression of Silica-induced pulmonary inflammation in Mice.</p><p><b>METHODS</b>Sixty Balb/c mice were randomly divided into 4 groups, normal control group, silicious group, suppressive oligodeoxynucleotides (Sup ODN) group, control oligodeoxynucleotides (Con ODN) group. Except the normal control group injected normal saline, the rest groups were induced by the intratracheal instillation of 0.1 ml (5 g/L) of sterilized silica suspension. Sup ODN group and Con ODN group were treated by i.p. injection of 0.3 ml (1mg/mL) of suppressive or control ODN 3 h before silica administration. After 7 days, the animals were killed and levels of IFN-γ were detected by ELISA. The pathologic changes in lung tissues of mice were observed with HE staining. Expressions of IFN-γ and pSTAT4 in lung tissue were detected with immunohistochemistry and quantified by Image-Pro Plus 7.0.</p><p><b>RESULTS</b>HE staining showed that the lung tissue of silicious group were damaged seriously than Sup ODN group. Compared with the normal control group (serum: (280.1±41.3) pg/ml, lung tissue: (0.249±0.373), IFN-γ increased in silicious group (serum: (886.3±81.7) pg/ml, lung tissue: (0.270±0.300) (P < 0.05). Compared with the normal control group and Con ODN group [(894.5±91.6) pg/ml], IFN-γ in the serum of Sup ODN group decreased significantly (P < 0.01). Compared with the silicious group , IFN-γ in lung tissue decreased in Sup ODN group (0.241±0.250) (P < 0.05). Compared with the normal control group (0.279±0.353), pSTAT4 in lung tissue increased significantly in silicious group (0.313±0.231) (P < 0.01). Compared with the silicious group, pSTAT4 in lung tissue decreased significantly in Sup ODN group (0.269±0.523) (P < 0.01).</p><p><b>CONCLUSION</b>Sup ODN attained protective effect on Silica treated mice by suppressing expression of IFN-γ and pSTAT4.</p>

Amino acids 395-416 in DNA binding domain of STAT4 is involved in IL-12-induced nuclear import of STAT4 / 生理学报

The purpose of the present study is to explore the mechanism of IL-12-induced nuclear import of signal transducer and activator of transcription 4 (STAT4). Assayed by analyses of homology alignment of STATs, amino acids 395-416 in DNA binding domain was found to be a potential dimer-specific nuclear localization signal (dsNLS) of STAT4. Therefore, several plasmids were constructed. Wild-type STAT4 was inserted into the SalI and BamHI sites of pEGFP-C1 for the construction of plasmid pEGFP-STAT4. The DNA fragment of STAT4 with the deletion of amino acids 395-416 was amplified by RCR and introduced into the SalI and BamHI sites of pEGFP-C1 which was named pEGFP-STAT4-Del. Classic NLS DNA sequence of SV40 T antigen was inserted into the XhoI and HindIII sites of pEGFP-C1. This plasmid was named as pEGFP-NLS and used as a positive control. Plasmid pEGFP-NLS-STAT4-Del was constructed by inserting STAT4-Del into SalI and BamHI sites of pEGFP-NLS. These plasmids were transiently transfected into Caski cells, respectively. The results showed that, after these transfected cells were stimulated by IL-12, wild type STAT4 existed in the cytoplasm at 0 min, and was predominantly localized to the nucleus at 45 min, and distributed in both cytoplasm and nucleus at 60 min, suggesting that STAT4 translocates from cytoplasm into nucleus and finally re-entries into the cytoplasm during the stimulation of IL-12. However, deletion mutant of STAT4 was arrested in cytoplasm during the IL-12 stimulation. Leptomycin B, which specifically blocks protein export from nucleus into cytoplasm, was used to further demonstrate whether STAT4-Del is transferred into nucleus even with stimulation of IL-12. After the transfected cells were pre-treated by leptomycin B, the wild type STAT4 was mainly localized in nucleus after the IL-12 stimulation, suggesting that STAT4 was translocated from cytoplasm into nucleus by the stimulation of IL-12. On the other hand, the deletion mutant of STAT4 distributed in cytoplasm throughout, implying that the mutant STAT4 lacking of amino acids 395-416 cannot move into nucleus. Furthermore, the insertion of classic NLS into EGFP-STAT4-Del restored nuclear import of STAT4-Del. These results suggest the amino acids 395-416 is a dsNLS mediating IL-12-stimulated nuclear import of activated STAT4.

Comparison of the status of STAT4 tyrosine phosphorylation in peripheral T-lymphocytes induced by IL-12 in rheumatoid arthritis and osteoarthritis / 中国骨伤

<p><b>OBJECTIVE</b>To compare the levels of STAT4 tyrosine phosphorylation in peripheral T-lymphocytes induced by IL-12 in rheumatoid arthritis (RA) and osteoarthritis (OA).</p><p><b>METHODS</b>From May 2007 to August 2009, peripheral blood mononuclear cells (PBMCs) were isolated from RA patients [RA group, all the cases were female, the age was from 28 to 55 years with an average of (45.0 +/- 13.0) years] and OA patients [OA group, all the cases also were female; the age was from 55 to 75 years with an average of (67.0 +/- 9.6) years]. The purity of T-lymphocytes from PBMCs was accredited by flow cytometry. The IL-12 of 50 ng/ml added in T-lymphocytes, the levels of STAT4 tyrosine phosphorylation were detected by western blot after different time intervals (0, 10, 30, 60 min).</p><p><b>RESULTS</b>The purity of T-lymphocytes were above 91% through diremption and depuration for peripheral blood monouclear cells. The levels of STAT4 tyrosine phosphorylation in T-lymphocytes from RA induced by IL-12 were higher than that from OA in the different times (10, 30, 60 min); after 30 min, its levels from RA and OA achieved to crest value.</p><p><b>CONCLUSION</b>STAT4 in peripheral T-lymphocytes of rheumatoid arthritis was more easily to be activated than osteoarthritis.</p>

IL-12-STAT4-IFN-gamma axis is a key downstream pathway in the development of IL-13-mediated asthma phenotypes in a Th2 type asthma model

IL-4 and IL-13 are closely related cytokines that are produced by Th2 cells. However, IL-4 and IL-13 have different effects on the development of asthma phenotypes. Here, we evaluated downstream molecular mechanisms involved in the development of Th2 type asthma phenotypes. A murine model of Th2 asthma was used that involved intraperitoneal sensitization with an allergen (ovalbumin) plus alum and then challenge with ovalbumin alone. Asthma phenotypes, including airway-hyperresponsiveness (AHR), lung inflammation, and immunologic parameters were evaluated after allergen challenge in mice deficient in candidate genes. The present study showed that methacholine AHR and lung inflammation developed in allergen-challenged IL-4-deficient mice but not in allergen-challenged IL-13-deficient mice. In addition, the production of OVA-specific IgG2a and IFN-gamma-inducible protein (IP)-10 was also impaired in the absence of IL-13, but not of IL-4. Lung-targeted IFN-gamma over-expression in the airways enhanced methacholine AHR and non-eosinophilic inflammation; in addition, these asthma phenotypes were impaired in allergen-challenged IFN-gamma-deficient mice. Moreover, AHR, non-eosinophilic inflammation, and IFN-gamma expression were impaired in allergen-challenged IL-12Rbeta2- and STAT4-deficient mice; however, AHR and non-eosinophilic inflammation were not impaired in allergen-challenged IL-4Ralpha-deficient mice, and these phenomena were accompanied by the enhanced expression of IL-12 and IFN-gamma. The present data suggest that IL-13-mediated asthma phenotypes, such as AHR and non-eosinophilic inflammation, in the Th2 type asthma are dependent on the IL-12-STAT4-IFN-gamma axis, and that these asthma phenotypes are independent of IL-4Ralpha-mediated signaling.

Association of HLA-DR4, PAD4, and STAT4 expression in the peripheral blood with disease activity in patients with rheumatoid arthritis / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the association of the expressions of human leukocyte antigen (HLA)-DR4, peptidyl arginine deiminase type4(PAD4), and signal transducer and activator of transcription 4 (STAT4) in the peripheral blood with the disease activity in patients with rheumatoid arthritis (RA).</p><p><b>METHODS</b>Twenty-four RA patients in active stage (DAS28 score>or=2.6) and 14 RA patients in remission stage (DAS28 score<2.6) were enrolled in this study, with 12 healthy volunteers as the control. The QuantiGene Plex method was used to measure the expression level of HLA-DR4, PAD4, and STAT4 mRNA, and the relationship between the expressions of these genes and the DAS28 score, levels of anti-cyclic citrullinated peptide antibody (anti-CCP antibody) and rheumatoid factor (RF) was analyzed.</p><p><b>RESULTS</b>The expressions of HLA-DR4, PAD4, and STAT4 were significantly higher in RA patients than in the healthy controls (P<0.05). The level of HLA-DR4 mRNA in the two RA groups showed no significant difference, but was significantly higher than that in the healthy controls. HLA-DR4 expression was not found to correlated to DAS28 score, anti-CCP antibody level or RF in the RA patients. The expressions of PAD4 and STAT4 were significantly different between the two RA groups (P<0.05). In the RA patients, PAD4 mRNA expression was positively correlated to DAS28 and anti-CCP antibody level (P<0.05), and STAT4 expression showed positive correlations to DAS28 and RF levels (P<0.05).</p><p><b>CONCLUSION</b>HLA-DR4, PAD4 and STAT4 are overexpressed in RA patients and may be involved in the pathogenesis of RA. The expressions of PAD4 and STAT4, but not HLA-DR4, are closely related to the disease activity of RA. Detection of peripheral blood PAD4 and STAT4 expressions can be helpful for evaluating the disease activity of RA.</p>

Impact of cyclosporine A on the expression of T-bet, GATA-3, relevant signal transduction molecules, cytokine and Th1/Th2 balance in patients with chronic aplastic anemia / 中国实验血液学杂志

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.

Variation in STAT4 is associated with systemic lupus erythematosus in Chinese Northern Han population / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Recent studies have identified signal transducer and activator of transcription 4 (STAT4) as a susceptibility gene for systemic lupus erythematosus (SLE) in different populations. In order to examine whether the allele distribution of the single nucleotide polymorphism (SNP) in gene STAT4 rs7574865 in patients with SLE is different from those of healthy controls in Chinese Northern Han population, we investigated whether the variants of STAT4 rs7574865 were associated with any specific clinical features of SLE.</p><p><b>METHODS</b>We genotyped SNPs in STAT4 rs7574865 in 252 patients with SLE and 497 healthy controls. All subjects were from the Northern part of Chinese Han population. The genotypes in rs7574865 were determined by polymerase chain reaction (PCR) and consequence direct sequencing of PCR products in the DNA samples.</p><p><b>RESULTS</b>There was a significant difference in distribution of the SNPs in rs7574865 between the SLE patients and healthy controls. Compared with healthy controls, there was a significant correlation between TT genotypes in rs7574865 and the risk of SLE when GG genotype was used as a reference genotype after adjusting for gender and age. The frequency of T allele in the SLE patients was strongly significantly higher than that of healthy controls. Furthermore, there was a significant difference in the distribution of SNP in rs7574865 between male and female SLE patients, when compared with healthy controls. The frequency of T allele in rs7574865 in male patients was significantly higher than that of male healthy controls or female patients. There was no significant correlation between the frequencies of T allele in STAT4 rs7574865 and the clinical features of SLE.</p><p><b>CONCLUSIONS</b>The SNP rs7574865 in STAT4 is strongly associated with risk of SLE in the Chinese Northern Han population. The TT genotype and T allele in STAT4 rs7574869 are susceptibility factors for SLE, especially for male SLE patients.</p>

Increase of NADPH-diaphorase Expression in Hypothalamus of Stat4 Knockout Mice

Signal transducer and activator of transcription 4 (STAT4), a STAT family member, mediates interleukin 12 (IL12) signal transduction. IL12 is known to be related to calorie-restricted status. In the central nervous system, IL12 also enhances the production of nitric oxide (NO), which regulates food intake. In this study, the expression of neuronal NO synthase (Nos1), which is also related to food intake, was investigated in the hypothalamic areas of Stat4 knockout (KO) mice using nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry, a marker for neurons expressing Nos1 enzyme. Western blots were also performed to evaluate Nos1 and Fos expression. Wild-type Balb/c (WT group, n=10 male) and Stat4 KO mice (Stat4 KO group, n=8 male) were used. The body weight and daily food intake in the WT group were 22.4+/-0.3 and 4.4 g per day, while those in the Stat4 KO group were 18.7+/-0.4 and 1.8 g per day, respectively. Stat4 mice had lower body weight and food intake than Balb/c mice. Optical intensities of NADPH-d-positive neurons in the paraventricular nucleus (PVN) and lateral hypothalamic area (LHA) of the Stat4 KO group were significantly higher than those of the WT group. Western blotting analysis revealed that the hypothalamic Nos1 and Fos expression of the Stat4 KO group was up-regulated, compared to that in the WT group. These results suggest that Stat4 may be related to the regulation of food intake and expression of Nos1 in the hypothalamus.

Expression of interleukin-12 and its signaling molecules in peripheral blood mononuclear cells in systemic lupus erythematosus patients / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To determine the in vitro expression of interleukin-12 (IL-12) and its effect on signal transducers and activators of transcription (STAT) signaling molecules in peripheral blood mononuclear cells (PBMCs) in patients with systemic lupus erythematosus (SLE).</p><p><b>METHODS</b>Peripheral blood mononuclear cells in 39 patients with definite systemic lupus erythematosus and 11 healthy volunteers were collected. Expression of IL-12 P40mRNA in PBMCs was determined with reverse transcription-polymerase chain reaction (RT-PCR). Quantity of IL-12 protein supernatant was measured by enzyme-linked immunosorbent assay (ELISA). The levels of phosphorylated STAT3 and STAT4 signaling molecules in PBMCs were detected by immunoblot.</p><p><b>RESULTS</b>Levels of IL-12 protein and mRNA expression in patients with active or inactive SLE were significantly higher than those in controls. Phytohemagglutinin (PHA ) may promote the expression of IL-12. IL-12 alone induced the phosphorylation of STAT3 and STAT4 in PBMCs from patients with SLE, especially in active SLE. However it had no obvious effect on normal PBMCs. Phosphorylated STAT3 and STAT4 might be observed in normal PBMCs treated with IL-12 plus PHA.</p><p><b>CONCLUSION</b>IL-12 is produced aberrantly in patients with SLE. IL-12 might exert its biological role in SLE via the aberrantly phosphorylated STAT3 and STAT4 signaling molecules.</p>