Association analysis between genetic variants in STAT4 and pathological characteristics of primary liver cancer / 中华疾病控制杂志

Objective To investigate the effect of genetic variants in STAT4 and its interaction with exercise on the pathological characteristics of patients with liver cancer. Methods In the 601 new patients with primary liver cancer,

Prokaryotic expression and purification of His-tagged-STAT4 (565-748 amino acid) fusion protein / 中国免疫学杂志

Objective:To construct His-tagged peptide of human STAT4 (565-748 amino acid) expression vector and induce its expression in Escherichia coli,followed by purification.Methods:STAT4 gene fragment encoding C-terminal peptide of 565-748 amino acid was amplified by PCR using pEGFP-STAT4 as the template.The PCR product was inserted into prokaryotic expression vector pET-28a and was transformed into component E.coli BL21 cells.By isopropyl-β-D-thiogalactoside(IPTG) induction,fusion protein was found to be expressed in the inclusion body and was denatured by using the urea denaturation buffer followed by renaturation and purifi-cation.Finally the purified protein was confirmed by Western blot.Results:The STAT4 truncated gene encoding 565-748 amino acids peptide was amplified by PCR and inserted into pET-28a vector.After the recombined plasmid was transformed into component BL21, the His-tagged-STAT4 (565-748 amino acids) fusion protein was induced and obtained after denaturation,refolding,purification and dialysis.Conclusion:The eukaryotic expression vector containing the truncated human STAT4 gene encoding 565-748aa peptide has been successfully constructed and the fusion protein was obtained.

The roles of STAT3 in osteogenesis of bone mesenchymal stem cells / 医用生物力学

Orthodontic tooth movement is a dynamic process, which includes bone resorption on the pressure side and osteogenesis on the tension side. Bone mesenchymal stem cells (BMSCs), which are force-sensitive cells, have potentials for differentiation into cells with various types. Their biological characteristics can change functionally according to the appropriate stimulation in vitro, in order to reach the optimal demand of the stimulation. Many signal pathways are involved in osteogenesis. Signal transducers and activators of transcription 3 (STAT3) is a ubiquitously expressed transcription factor, mediating cell proliferation, differentiation, survival, apoptosis and cellular immunity. It has been reported that STAT3 can regulate the differentiation process of BMSCs into osteoblasts. This paper summarizes the recent progress about effect of STAT3 on bone differentiation of BMSCs and the possible mechanism.

Schistosoma japonicum infection in obese mouse insulin resistance / 安徽医科大学学报

Objective To investigate Schistosoma japonicum infection on mice high-fat diet of insulin resistance. Methods 36 male C57 BL/6 J mice were randomly assigned into three equal groups: normal control group ( NC group) , high-fat diet group ( HF group) and high-fat diet with Schistosoma japonicum infected group ( HSJ group) . Specimen was collected 6 and 12 weeks after high-fat diet, separately. The levels of fasting blood glucose ( FBG) , fasting plasma insulin resistance index ( FINS) and insulin ( HOMA-IR) were detected. Interferon-γ( IFN-γ) ,in-terleukin-4 ( IL-4 ) and singal transductor and activator of transcription-4 ( STAT4 ) singal transductor and activator of transcription-6 (STAT6)were detected by ELISA and immunohistochemical method. Results The mice from HF group showed higher levels of HOMA-IR than those from NC groups by the end of 6 and 12 weeks after infection( P<0. 01 );the levels of HOMA-IR in mice from HSJ group were lower than NC group and HF group by the end of 12 weeks(P<0. 05);the levels of IL-4 in mice from HSJ group were higher than NC group and HSJ group by the end of 6 and 12 weeks after infection ( P<0. 05 ); the levels of STAT6 in mice from HSJ group were higher than HF group by the end of 12 weeks after infection ( P<0. 05 );the levels of STAT4 in mice from HF group were higher than NC group by the end of 6 and 12 weeks after infection. Conclusion Schistosome japonicum chronic infection may improve insulin resistance in obese mice with induced STAT6 protein expressed in liver tissue and secrete IL-4,providing new ideas for the prevention and treatment of diabetes.

STAT4 pathway activates homocysteine-induced proliferation, migration and senescence of human aorta smooth muscle cells / 中华普通外科杂志

Objective To investigate the role and mechanism of signal transducer and activator of transcription 4 (STAT4) in homocysteine (Hcy)-induced proliferation,migration and senescence of human aorta smooth muscle cells (VSMCs).Methods After VSMCs were incubated with Hcy (0-0.50 mmol/L) for various time periods,a CCK-8 assay was performed to determine proliferation activity.Modified Boyden chamber system (Transwell apparatus) was used to examine migration ability.A SA-β-gal staining kit was used to determine senescence status.Western blotting was performed to examine the expressions of STAT4 and phosphorylated STAT4 (p-STAT4) proteins,and ELISA was performed to examine MCP-1 expression.Results Hcy (from 0.05 mmol/L) significantly increased the proliferation of VSMCs (P ＜ 0.05).Hcy (from 0.10 mmol/L) significantly increased the migration of VSMCs (P ＜ 0.05).Hcy promoted the senescence of VSMC in a concentration-dependent manner,and significantly increased VSMC senescence when the concentration of Hcy reached 0.10 mmol/L (P ＜ 0.05).Hcy (from 0.10 mmol/L) treatment significantly increased the expression of p-STAT4 (P ＜ 0.05) and MCP-1 (P ＜ 0.05).Conclusions Hcy increases the proliferation,migration and senescence of VSMCs,probably by the activation of STAT4 pathway.

Variants in the IFN ? transcription factor genes TBET, STAT1, STAT4, and HLX and the risk of pulmonary tuberculosis in a Colombian population: a case-control study / Variantes en los factores de transcripción para IFN ?, TBET, STAT1 , STAT4 y HLX , y el riesgo de desarrollar tuberculosis pulmonar en un estudio de casos y controles de una población colombiana

Introduction: Interferon gamma (IFN ? ) is the most potent cytokine involved in the control of Mycobacterium tuberculosis ( Mtb ), the etiological agent of human tuberculosis (TB). Patients with active TB present reduced levels of IFN ? , which may explain the lack of effective immunity against Mtb in these patients. The diminished expression of or functional alterations in trans-acting factors that regulate IFN ? gene expression may explain the reduced levels of IFN ? in TB patients. Objective: To investigate the relationships of genetic variants in the transcription factors TBET, STAT1, STAT4, and HLX to susceptibility/resistance to pulmonary TB. Materials and methods: Eight candidate single-nucleotide polymorphisms (SNPs) were selected, and genotyped in 466 unrelated pulmonary TB patients and 300 healthy controls from Colombia, and the allelic and genetic associations with TB were analyzed. Results: The results indicate that no SNP in the transcription factors studied is associated with TB. However, polymorphism rs11650354 in the TBET gene may be associated with a decreased risk of TB; the TT genotype was significantly associated with TB protection in a recessive genetic model (OR=0.089, 95% CI: 0.01-0.73, p=0.0069), although this association was not maintained after multiple test correction (EMP2= 0.61). Conclusion: In this study, the rs11650354 variant of TBET was suggested to promote resistance to TB in a Colombian population. A future replication case-control study using additional samples will be necessary to confirm this suggestive association.

Introducción. El interferón gama (IFN ? ) es la citocina más potente para controlar la infección por Mycobacterium tuberculosis , el agente etiológico de la tuberculosis humana. Los pacientes con tuberculosis activa presentan reducción de los niveles de IFN ? , lo cual parece explicar la inmunidad poco efectiva contra el bacilo. La disminución de su expresión o alteraciones funcionales de los factores transactivadores del promotor del gen de IFN ? , podrían explicar la reducción de los niveles de IFN ? en los pacientes con tuberculosis. Objetivo. Determinar la asociación de variantes genéticas en los factores de transcripción TBET STAT1, STAT4 y HLX con sensibilidad o resistencia a tuberculosis pulmonar. Materiales y métodos. Se seleccionaron ocho polimorfismos de un solo nucleótido ( Single-Nucleotide Polymorphism , SNP) y se estableció su genotipo, en 466 pacientes con tuberculosis pulmonar y 300 controles sanos en Colombia; además, se hizo un análisis de asociación alélica y genética. Resultados. Los resultados indican que los SNP de los factores de transcripción estudiados no están asociados con tuberculosis; sin embargo, el polimorfismo rs11650354 en TBET puede estar implicado en la disminución de riesgo de tuberculosis. El genotipo TT de TBET se asoció significativamente con protección contra tuberculosis usando un modelo genético recesivo (OR=0,089; CI 95% : 0,01-0,73; p=0,0069); sin embargo, la corrección mediante pruebas múltiples de ajuste abolió esta asociación ( Empirical P Value, EMP2=0,61). Conclusión. En este estudio se sugiere un efecto de la variante rs11650354 de TBET sobre la resistencia a la tuberculosis en la población colombiana. Es necesario desarrollar un estudio de replicación usando muestras adicionales para confirmar esta asociación sugestiva.

Ganoderma lucidum polysaccharides promote Th1 cell differentiation of human peripheral blood lymphocytes through the upregulation of STAT4 / 中华微生物学和免疫学杂志

Objective To study the effects of Ganoderma lucidum polysaccharide (GLP) on PBMCs and the related immune mechanism.Methods PBMCs from cancer patients and healthy donors were isolated and treated with different doses of Ganoderma lucidum polysaccharides (10 ng/ml,50 ng/ml and 100 ng/ml).DC cell costimulatory molecules (HLA-DR,CD83,and CD11 c),Th1 (CD3 + CD8-IFN-γ+) cells,Th2 (CD3 + CD8-IL-4+) cells and NK (CD3-CD56+) were analyzed by FCM.Furthermore,The CD3+ CD4+ Th ceils were separated by immunomagnetic beads and stimulated with Ganoderma lucidum polysaccharides at different concentrations in culture.After 24 h,the cytokine expression levels of Th1 and Th2were detected by RT-PCR.The expressions of Th1 differentiation-related transcription factor,STAT4,were analyzed by Western blot.Results Ganoderma lucidum polysaccharides can significantly stimulate in vitro Thl cell differentiation (P＜0.01) in a dose depend manner.It correlates with an increased expression of STAT4 and the elevated mRNA expression levels of Th1 cytokineincluding IL-12,IFN-γ and TNF-α (P＜0.01).Conclusion Ganoderma lucidum polysaccharides may promote Th1 differentiation and increase the secretion of Th1 cvtokines through the upregulation of STAT4.

Associations of IRF7/KIAA1542 and STAT4 polymorphisms with systemic lupus erythematosus in Chinese Han population / 中华检验医学杂志

Objective To investigate genetic polymorphisms of IRF7/KIAA1542 (rs4963128, rs2246614) and STAT4 (rs7574865) and their relationships with lupus nephritis and various autoantibodies present in Chinese Han population of SLE patients. Methods A total of 748 SLE patients and 750 healthy controls belonging to the Chinese population were enrolled into this study. They were genotyped using MALDI-TOF-MS method. Autoantibodies including anti-SSA, anti-SSB, anti-Sm, anti-RNP and anti-dsDNA were determined either by indirect immunofluorescence or double immunodiffusion methods. Results In the healthy group, rs7574865 (STAT4) T/T, T/G, G/G genotype frequency and T, G allele frequencies were as follows: 9.4% , 45. 6% , 45. 0% , 32. 2% , 67. 8% , the corresponding case group as follows: 17.0% , 48.1%, 34.9%, 41.0%, 59.0%, genotype and allele frequencies were significantly different (x2 = 26.30, P<0.01). Compared with the control group, in the case group, T/T genotype frequency and T allele frequency were significantly increased, and in three genetic models ( additive model, dominant model, recessive model), the genotype frequencies were significant difference (P <0. 01). Two polymorphic loci of rs4963128 and rs2246614 (IRF7/KIAA1542) were not statistically significant (x2 =4.49,5.32,P>0.05) in case group and control group, but the rs2246614 genotype frequencies had a statistically significant in recessive model (P <0. 05) , whereas rs4963128 genotype frequencies was no significant difference in the three genetic model (P=0.068, 0.958, 0.067, respectively). In the clinical subphenotype analysis, IRF7/KIAA1542 (rs4963128) in lupus nephritis group (OR = 2. 69, 95% CI = 1. 89-3. 82, P < 0.01) ,anti-SSA antibody group ( OR = 0. 61, 95% CI = 0. 43-0. 87, P < 0. 05 ) and anti-SSB antibody group ( OR =0. 36, 95% CI = 0. 23-0. 56, P < 0.01) of the analysis were statistically significant. At the same time, IRF7/KIAA1542 (rs2246614) in the joint comparison of positive and negative symptoms were also statistically significant (OR=1.34, 95% CI = 1. 06-1. 69, P < 0. 05). Conclusions This findings provide strong evidence suggesting that STAT4 ( rs7574865 ) is the susceptible factor of SLE in Chinese Han population. However, there is not a significant relationships between IRF7/KIAA1542 (rs4963128, rs2246614) polymorphisms and the risk of SLE, but the associations of IRF7/KIAA1542 (rs4963128, rs2246614) with the a variety of clinical subphenotypes, such as lupus nephritis, joint symptoms and production of anti-SSA antibody and anti-SSB antibody implicates IRF7/KIAA1542 as a putative candidate gene of SLE.

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.