PKD3 promotes metastasis and growth of oral squamous cell carcinoma through positive feedback regulation with PD-L1 and activation of ERK-STAT1/3-EMT signalling / 国际口腔科学杂志·英文版

Oral squamous cell carcinoma (OSCC) has a high incidence of metastasis. Tumour immunotherapy targeting PD-L1 or PD-1 has been revolutionary; however, only a few patients with OSCC respond to this treatment. Therefore, it is essential to gain insights into the molecular mechanisms underlying the growth and metastasis of OSCC. In this study, we analysed the expression levels of protein kinase D3 (PKD3) and PD-L1 and their correlation with the expression of mesenchymal and epithelial markers. We found that the expression of PKD3 and PD-L1 in OSCC cells and tissues was significantly increased, which correlated positively with that of mesenchymal markers but negatively with that of epithelial markers. Silencing PKD3 significantly inhibited the growth, metastasis and invasion of OSCC cells, while its overexpression promoted these processes. Our further analyses revealed that there was positive feedback regulation between PKD3 and PD-L1, which could drive EMT of OSCC cells via the ERK/STAT1/3 pathway, thereby promoting tumour growth and metastasis. Furthermore, silencing PKD3 significantly inhibited the expression of PD-L1, and lymph node metastasis of OSCC was investigated with a mouse footpad xenograft model. Thus, our findings provide a theoretical basis for targeting PKD3 as an alternative method to block EMT for regulating PD-L1 expression and inhibiting OSCC growth and metastasis.

MicroRNA-146a inhibition promotes total neurite outgrowth and suppresses cell apoptosis, inflammation, and STAT1/MYC pathway in PC12 and cortical neuron cellular Alzheimer's disease models

This study aimed to explore the effect of microRNA (miR)-146a inhibition on regulating cell apoptosis, total neurite outgrowth, inflammation, and STAT1/MYC pathway in Alzheimer's disease (AD). PC12 and cortical neuron cellular AD models were constructed by Aβ1-42 insult. For the former model, nerve growth factor (NGF) stimulation was previously conducted. miR-146a inhibitor and negative-control (NC) inhibitor were transfected into the two cellular AD models, and then cells were named miR-inhibitor group and NC-inhibitor group, respectively. After transfection, cell apoptosis, total neurite outgrowth, supernatant inflammation cytokines, and STAT1/MYC pathway were detected. miR-146a expression was similar between PC12 cellular AD model and control cells (NGF-stimulated PC12 cells), while miR-146a expression was increased in cortical neuron cellular AD model compared with control cells (rat embryo primary cortical neurons). In both PC12 and cortical neuron cellular AD models, miR-146a expression was reduced in miR-inhibitor group compared with NC-inhibitor group after transfection. Furthermore, cell apoptosis was attenuated, while total neurite outgrowth was elevated in miR-inhibitor group compared with NC-inhibitor group. As for supernatant inflammatory cytokines, tumor necrosis factor-α, interleukin (IL)-1β, IL-6, and IL-17 levels were lower in miR-inhibitor group than in NC-inhibitor group. Additionally, STAT1 and c-Myc mRNA and protein expressions were attenuated in miR-inhibitor group compared with NC-inhibitor group. In conclusion, miR-146a potentially represented a viable therapeutic target for AD.

Nova mutação no gene STAT1 associada com candidíase mucocutânea crônica / New STAT1 gene mutation associated with chronic mucocutaneous candidiasis

Mutações no gene STAT1 (signal transducer and activator of transcription 1) têm sido identificadas como responsáveis pela maioria dos casos sindrômicos da candidíase mucocutânea crônica com herança autossômica dominante (AD). Nesse artigo, descrevemos uma menina de 7 anos que apresentou candidíase da mucosa oral e unhas, além de infecção disseminada da pele e couro cabeludo por Microspora gipseum. Recentemente, a paciente foi diagnosticada e tratada de meningite por Cryptococcus neoformans. Na família não existem outros casos de candidíase. A avaliação imunológica incluiu a detecção de subpopulações de linfócitos (CD3, CD4, CD8, CD20 e células NK), assim como a dosagem de IgG, IgA, IgM e IgE, subclasses de IgG e autoanticorpos. Excluindo-se discreta diminuição de CD3, CD4, CD8, NK e leve aumento de IgG1, os demais exames estiveram dentro da normalidade. O sequenciamento do exoma detectou uma rara mutação em heterozigose no exon 14 do domínio de ligação do DNA (DNA-binding domain) do gene STAT1, ocasionando um provável ganho de função (GOF) responsável pela doença (Gly384Asp). Essa variação foi também identificada pelo sequenciamento de Sanger, não estando reportada nos bancos de dados públicos e apresentando elevado potencial de dano (índice CADD=32). Será interessante contarmos com informações clínicas e estudos com outros pacientes para conhecermos mais essa mutação patológica. Além da apresentação do caso, discutiremos as formas de tratamento existentes.

STAT1 (signal transducer and activator of transcription 1) gene mutations have been identified as responsible for most syndromic cases of chronic mucocutaneous candidiasis with autosomal dominant (AD) inheritance. In this article, we described a 7-year-old girl who presented with candidiasis of the oral mucosa and nails, as well as disseminated infection of the skin and scalp caused by Microsporum gypseum. Recently, the patient was diagnosed and treated for Cryptococcus neoformans meningitis. There are no other cases of candidiasis in the family. The immunological evaluation consisted of detection of subpopulations of lymphocytes (CD3, CD4, CD8, CD20, and NK cells), as well as measurement of IgG, IgA, IgM, and IgE, IgG subclasses, and autoantibodies. Excluding a slight decrease in CD3, CD4, CD8, NK and a minimal increase in IgG1, the others were within normal limits. Exome sequencing detected a rare heterozygous variation in exon 14 of the DNA-binding domain of the STAT1 gene, causing a probable gain of function (GOF) responsible for the disease (Gly384Asp). This variation was also identified by Sanger sequencing, but it was not reported in public databases and had a high potential for damage (Combined Annotation-Dependent Depletion [CADD] score = 32). Having clinical information and conducting studies of other patients will be helpful to learn more about this pathological mutation. In addition to the presentation of the case, we will discuss the existing forms of treatment.

Interferon-gamma signaling is downregulated in peripheral blood mononuclear cells from asthma patients / A sinalização de interferon-gama é diminuída em células mononucleares do sangue periférico de pacientes asmáticos

Introduction: Interferon-gamma (IFN-g) signaling is mediated by crosstalk of receptors, such as IFN-g receptor 1 (IFN-g R1), transcription factors, such as signal transducer and activator of transcription 1 (STAT1) and suppressors of cytokine signaling 1 (SOCS1). Here, we evaluated the role of IFN-g signaling in peripheral blood mononuclear cells (PBMCs) from asthma patients and control individuals. Methods: PBMCs from adult healthy nonasthmatic controls (n = 12; male and female, 18-60 years old) and patients diagnosed with asthma (n = 18; male and female, 18-60 years old) were stimulated with IFN-g (0.25, 0.5 and/or 1.0 ng/mL) and, after 24h, the production of CXC motif chemokine 10 (CXCL10) was evaluated (by enzyme linked immunosorbent assay) as well as the expression of IFN-g R1, STAT1 (both by flow cytometry assay) and SOCS1 (by real-time qPCR assay). Results: CXCL10 production was reduced in a dose-dependent manner in PBMCs from asthma patients stimulated with IFN-g when compared to control individuals. While IFN-g induced an increase in IFN-g R1 expression and phosphorylated STAT1 (pSTAT1) activation in PBMCs from the control group, a reduction in both IFN-g R1 and pSTAT1 was observed in PBMCs from asthma patients. IFN-g increased SOCS1 mRNA expression in PBMCs from asthma patients when compared to IFN-g-stimulated cells from control individuals. Conclusion: Taken together, our results demonstrated that IFN-g signaling is downregulated in asthma patients.

Introdução: A sinalização de interferon-gama (IFN-g) é mediada por receptores, como o receptor 1 de IFN-gama (IFN-gR1), fatores de transcrição, como o transdutor de sinal e o ativador de transcrição 1 (STAT1) e supressores de sinalização de citocina 1 (SOCS1). Neste trabalho, avaliamos o papel da sinalização de IFN-g em células mononucleares do sangue periférico (PBMCs) de indivíduos com asma e controle. Métodos: Células mononucleares do sangue periférico (PBMCs) de adultos saudáveis e não asmáticos (n = 12, homens e mulheres, 18-60 anos) e pacientes diagnosticados com asma (n = 18, homens e mulheres, 18-60 anos) foram estimuladas com IFN-g (0,25, 0,5 e/ou 1,0 ng/mL) e após 24 horas a produção de CXCL10 foi avaliada por ensaio de imunoabsorção enzimática (ELISA), bem como o receptor 1 de IFN-g (IFN-g R1). Também foram avaliadas as expressões do transdutor de sinal e ativador da transcrição 1 (STAT1) (por citometria de fluxo) e supressor de expressão de sinalização de citocinas 1 (SOCS1) (por ensaio qPCR em tempo real). Resultados: A produção de CXCL10, uma quimiocina induzida por IFNg, foi reduzida de maneira dependente da dose em PBMCs de pacientes com asma estimulados com IFN-g (0,25-1,0 ng/mL) quando comparado ao grupo controle. Enquanto IFN-g induziu um aumento da expressão de IFN-g R1 e ativação da fosforilação de STAT1 (pSTAT1) em PBMCs do grupo controle, uma redução de ambas (IFN-g R1 e pSTAT1) foi observada em PBMCs de pacientes com asma. O IFN-g aumentou as PBMCs de expressão do mRNA de SOCS1 de pacientes com asma quando comparado às células estimuladas por IFN-g do controle. Conclusão: Em conjunto, nossos resultados demonstraram que a sinalização de IFN-g é sub-regulada em pacientes com asma.

Relationships Between Expression level of MicroRNA-146a, STAT1 Protein and Clinical Characteristics in Children with Acute Lymphoblastic Leukemia / 中国实验血液学杂志

OBJECTIVE@#To analyze the relationships between expression levels of serum microRNA-146a, STAT1 protein and clinical characteristics in children with acute lymphoblastic leukemia (ALL).@*METHODS@#A total of 102 children diagnosed as ALL in our hospital from June 2014 to June 2016 were enrolled, and were compared by into groups according to clinical characteristics including sex, age, lymphocyte type, disease risk, chemotherapy stage and gene mutation. Fifty healthy children were chosen as control group. The relative expression of microRNA-146a and STAT1 gene was detected by real-time RT-PCR and the relative level of STAT1 protein was detected by Western blot. The difference of microRNA-146a and STAT1 protein levels between clinical factors and laboratory indexs were compared. Followed-up for 3 years, The difference of overall survival (OS) rates between ALL children with different microRNA-146a and STAT1 protein were compared.@*RESULTS@#The levels of microRNA-146a, STAT1 mRNA and protein in ALL children were significantly higher than those in control group (P＜0.05), but there were no significantly differences in sex, age and lymphocyte type grouping in ALL children (P＞0.05). There were significantly differences in different disease risk, chemotherapy stage and gene mutation groups in ALL children (P＜0.05). Followed-up for 3 years, the OS rate of ALL children with high microRNA-146a and STAT1 protein levels were better than those with low microRNA-146a and STAT1 protein levels (P＜0.05).@*CONCLUSION@#The up-regulation of microRNA-146a and STAT1 protein may be involved in occurrence and development of ALL, which closely relates to clinical characteristics in ALL children, such as disease risk, chemotherapy stage and gene mutation.

Paeonol inhibits macrophage M1 polarization by down-regulating miR-155/JAK1-STAT1 pathway / 中国中药杂志

The aim of this paper was to investigate the effect and mechanism of paeonol on peritoneal macrophage M1 polarization in mice, explore whether the intervention action is related to the down-regulation of miR-155 and the inhibition of downstream JAK1-STAT1 pathway, and provide a new idea for the molecular mechanism of paeonol against atherosclerosis(AS). Lipopolysaccharide(LPS) and interferon-γ(IFN-γ) were used to stimulate macrophages for 24 hours to establish the M1 polarization model, and paeonol was given 24 hours before co-stimulation to provide a pre-protective effect on cells. CCK-8 assay was used to detect the cells damage induced by LPS and IFN-γ co-stimulation; flow cytometry was used to detect the expression of M1 surface markers F4/80 and CD86. ELISA was used to detect the secretion of interleukin 6(IL-6) and tumor necrosis factor-α(TNF-α) in supernatant. RT-qPCR was used to detect the expression of miR-155, and Western blot was used to detect the protein expression at JAK1-STAT1-SOCS1 pathway. The results showed that LPS and IFN-γ had no obvious damage to the cells at the optimal concentration, but they induced macrophages polarized to M1, resulted in high expression of M1 type marker factors F4/80 and CD86 on the cell surface, and increased secretion of IL-6 and TNF-α on the cell surface(P<0.05 or P<0.01). Paeonol significantly reduced the LPS and IFN-γ-induced high expression of F4/80 and CD86, the secretion of inflammatory factors IL-6 and TNF-α(P<0.05 or P<0.01), decreased the expression level of miR-155, significantly down-regulated the protein phosphorylation level of JAK1-STAT1 and up-regulated the protein expression of SOCS1(P<0.01) in RAW264.7 cells. The results showed that paeonol could inhibit M1 polarization of macrophages by down-regulating cell surface marker factors and inflammatory factors secreted by cells, which may be related to the down-regulation of miR-155 expression and the inhibition JAK1-STAT1 pathway activation.

Di (2-ethylhexyl) phthalate Disorders Lipid Metabolism via TYK2/STAT1 and Autophagy in Rats / 生物医学与环境科学（英文）

OBJECTIVE@#Previous studies have indicated that the plasticizer di (2-ethylhexyl) phthalate (DEHP) affects lipid accumulation; however, its underlying mechanism remains unclear. We aim to clarify the effect of DEHP on lipid metabolism and the role of TYK2/STAT1 and autophagy.@*METHODS@#In total, 160 Wistar rats were exposed to DEHP [0, 5, 50, 500 mg/(kg•d)] for 8 weeks. Lipid levels, as well as mRNA and protein levels of TYK2, STAT1, PPARγ, AOX, FAS, LPL, and LC3 were detected.@*RESULTS@#The results indicate that DEHP exposure may lead to increased weight gain and altered serum lipids. We observed that DEHP exposure affected liver parenchyma and increased the volume or number of fat cells. In adipose tissue, decreased TYK2 and STAT1 promoted the expression of PPARγ and FAS. The mRNA and protein expression of LC3 in 50 and 500 mg/(kg•d) groups was increased significantly. In the liver, TYK2 and STAT1 increased compensatorily; however, the expression of FAS and AOX increased, while LPL expression decreased. Joint exposure to both a high-fat diet and DEHP led to complete disorder of lipid metabolism.@*CONCLUSION@#It is suggested that DEHP induces lipid metabolism disorder by regulating TYK2/STAT1. Autophagy may play a potential role in this process as well. High-fat diet, in combination with DEHP exposure, may jointly have an effect on lipid metabolism disorder.

Bronchiectasis and Recurrent Respiratory Infections with a De Novo STAT1 Gain-of-Function Variant: First Case in Korea

Bronchiectasis is a chronic disease characterized by airway infection and inflammation, leading to permanent dilation of the bronchi. Evaluation of underlying etiology is important in managing young bronchiectasis patients with recurrent infections caused by unusual pathogens. The signal transducer and activator of transcription 1 (STAT1) protein plays a key role in STAT signaling and immune system regulation. Heterozygotes for gain-of-function (GOF) alleles of the STAT1 gene usually display autosomal dominant chronic mucocutaneous candidiasis (CMC) and a wide range of clinical features, such as bronchiectasis. Here, we report on a patient with CMC and bronchiectasis with various types of infections who carried a pathogenic variant of the STAT1 gene. The 24-year-old female presented with recurrent respiratory bacterial and nontuberculous mycobacterial infections complicated by severe bronchiectasis and CMC. Whole-exome sequencing revealed a c.800C>T (p.Ala267Val) heterozygous mutation in the STAT1 gene. Further analysis by Sanger sequencing of STAT1 from the patient and her parents revealed the patient had a de novo occurrence of the variant. This is the first report of a Korean patient with a GOF pathogenic variant in STAT1. Physicians should be aware of the existence of this variant as a genetic factor associated with CMC and bronchiectasis complicated by recurrent infection.

Interferon-free treatment for hepatitis C virus infection induces normalization of extrahepatic type I interferon signaling

BACKGROUND/AIMS: Hepatitis C virus (HCV) replicates in the peripheral blood mononuclear cells (PBMCs), leading to the production of type I interferons (IFNs). It is well known that the gene expression profile of PBMC is similar to that of the liver. The present study explored the dynamic gene expression profile of PBMCs collected from HCV-infected patients undergoing direct-acting antiviral (DAA) therapy. METHODS: A prospective cohort comprising 27 patients under DAA therapy was formed. Expression level of IFN-β and its downstream interferon-stimulated genes (ISGs) was measured in PBMCs before and after DAA treatment. Furthermore, immunoblotting was performed to identify the signaling molecules involved in the expression of ISGs. RESULTS: The pretreatment expression level of interferon-induced protein 44 (IFI44) and C-X-C motif chemokine ligand 10 (CXCL10) correlated with the pretreatment expression level of IFN-β. After DAA treatment, a significant decrease in the expression levels of IFN-β, IFI44, and CXCL10 was observed in the PBMCs. Furthermore, the pretreatment expression level of IFN-β and ISGs correlated with the level of signal transducer and activator of transcription 1 (STAT1) phosphorylation, and DAA treatment abrogated STAT1 phosphorylation. CONCLUSIONS: Pretreatment activation of IFN-β response is rapidly normalized after DAA treatment. The present study suggests that the decreased type I IFN response by the clearance of HCV might contribute to DAA-induced alleviation of extrahepatic manifestation of chronic HCV infection.

RIG-I: a multifunctional protein beyond a pattern recognition receptor

It was widely known that retinoic acid inducible gene I (RIG-I) functions as a cytosolic pattern recognition receptor that initiates innate antiviral immunity by detecting exogenous viral RNAs. However, recent studies showed that RIG-I participates in other various cellular activities by sensing endogenous RNAs under different circumstances. For example, RIG-I facilitates the therapy resistance and expansion of breast cancer cells and promotes T cell-independent B cell activation through interferon signaling activation by recognizing non-coding RNAs and endogenous retroviruses in certain situations. While in hepatocellular carcinoma and acute myeloid leukemia, RIG-I acts as a tumor suppressor through either augmenting STAT1 activation by competitively binding STAT1 against its negative regulator SHP1 or inhibiting AKT-mTOR signaling pathway by directly interacting with Src respectively. These new findings suggest that RIG-I plays more diverse roles in various cellular life activities, such as cell proliferation and differentiation, than previously known. Taken together, the function of RIG-I exceeds far beyond that of a pattern recognition receptor.

Suppressor of cytokine signaling 1 expression during LPS-induced inflammation and bone loss in rats

Abstract This study aimed to characterize the dynamics of suppressor of cytokine signaling (SOCS1) expression in a rat model of lipopolysaccharide-induced periodontitis. Wistar rats in the experimental groups were injected three times/week with LPS from Escherichia coli on the palatal aspect of the first molars, and control animals were injected with vehicle (phosphate-buffered saline). Animals were sacrificed 7, 15, and 30 days after the first injection to analyze inflammation (stereometric analysis), bone loss (macroscopic analysis), gene expression (qRT-PCR), and protein expression/activation (Western blotting). The severity of inflammation and bone loss associated with LPS-induced periodontitis increased from day 7 to day 15, and it was sustained through day 30. Significant (p < 0.05) increases in SOCS1, RANKL, OPG, and IFN-γ gene expression were observed in the experimental group versus the control group at day 15. SOCS1 protein expression and STAT1 and NF-κB activation were increased throughout the 30-day experimental period. Gingival tissues affected by experimental periodontitis express SOCS1, indicating that this protein may potentially downregulate signaling events involved in inflammatory reactions and bone loss and thus may play a relevant role in the development and progression of periodontal disease.

Expression profiles of PI3K, NF-κB, and STAT1 in peripheral blood mononuclear cells in children with bronchial asthma / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the expression profiles of PI3K, NF-κB, and STAT1 in peripheral blood mononuclear cells (PBMCs) in children with bronchial asthma, as well as their roles in the pathogenesis of asthma.</p><p><b>METHODS</b>Thirty children with acute exacerbation of bronchial asthma were enrolled as the asthma group, and 20 healthy children were enrolled as the control group. RT-PCR and Western blot were used to measure the mRNA and protein expression levels of PI3K, NF-κB, and STAT1 in PBMCs. A spirometer was used to compare the pulmonary function between the two groups. The correlations between the mRNA expression of PI3K, NF-κB, and STAT1 and pulmonary function in children with bronchial asthma were analyzed.</p><p><b>RESULTS</b>The asthma group had significantly higher mRNA and protein expression levels of PI3K, NF-κB, and STAT1 than the control group (P<0.05). Compared with the control group, the asthma group showed significant reductions in pulmonary function indices such as FEV1%, FEV1/FVC, and PEF% (P<0.05). In children with bronchial asthma, the mRNA expression levels of PI3K, NF-κB, and STAT1 were negatively correlated with FEV1%, FEV1/FVC, and PEF% (P<0.05).</p><p><b>CONCLUSIONS</b>The expression levels of PI3K, NF-κB, and STAT1 increase in children with asthma, and are negatively correlated with pulmonary function indices, suggesting that PI3K, NF-κB and STAT1 are involved in the development and progression of bronchial asthma in children.</p>

Antiviral and myocyte protective effects of IL-28A in coxsackievirus B3-induced myocarditis

Objective: This study aimed to investigate whether interleukin-28A (IL-28A) plays a role in murine myocarditis induced by coxsackievirus B3 (CVB3), and to explore its possible mechanism involved. Methods: Male BALB/c mice both infected and not infected by CVB3 were randomly divided into four groups (n = 40), untreated or treated with different doses of IL-28A for 4 days, and then sacrificed on days 4 and 7 post-infection. The heart samples were collected for histopathologic examination. Cardiac viral load was determined by a plaque assay. Additionally, immunoblot analysis, TUNEL assay, and immunohistochemistry were performed to examine the expression of signal transducer, activator of transcription 1 and 2 (STAT1 and STAT2), CVB3-induced apoptosis and the expression of Bcl-2, BAX and Caspase-3. Results: Compared to uninfected mice, the CVB3 infected mice exhibited higher mortality rate (p < 0.001), apparent inflammation and myocardial lesion (p < 0.01), and higher cardiac viral load (p < 0.01). After CVB3 infection, IL-28A treated mice presented no death (p < 0.001), reduced inflammation and myocardial lesion (p < 0.01), and lower viral load (p < 0.01) compared to untreated mice. Besides, treatment with IL-28A markedly increased the expressions of STAT1 and STAT2, and inhibited CVB3-induced apoptosis in myocardial cells with increased ratio of Bcl-2/BAX. Conclusion: The antiviral and myocyte protective effects of IL-28A in CVB3-inducedmyocarditis are regulated by STAT1 and STAT2. .

Anti-inflammatory Activity of Fucoidan with Blocking NF-kappaB and STAT1 in Human Keratinocytes Cells

Fucoidan, a sulfated polysaccharide is found in several types of edible brown algae. It has shown numerous biological activities; however, the molecular mechanisms on the activity against atopic dermatitis have not been reported yet. We now examined the effects of fucoidan on chemokine production co-induced by TNF-alpha/IFN-gamma, and the possible mechanisms underlying these biological effects. Our data showed that fucoidan inhibited the TNF-alpha/IFN-gamma-induced production of thymus and activation-regulated chemokine (TARC) and macrophagederived chemokine (MDC) mRNA in human keratinocytes HaCaT cells. Also, fucoidan suppressed phosphorylation of nuclear factor kappa B (NF-kappaB) and activation of signal transducer and activator of transcription (STAT)1 in a dose-dependent manner. In addition, fucoidan significantly inhibited activation of extracellular-signal-regulated kinases (ERK) phosphorylation. These data indicate that fucoidan shows anti-inflammatory effects by suppressing the expression of TNF-alpha/IFN-gamma-induced chemokines by blocking NF-kappaB, STAT1, and ERK1/2 activation, suggestive of as used as a therapeutic application in inflammatory skin diseases, such as atopic dermatitis.

Astragaloside IV regulates STAT1/IκB/NF-κB signaling pathway to inhibit activation of BV-2 cells / 中国中药杂志

<p><b>OBJECTIVE</b>The study was aimed to investigate the inhibitory effect and mechanism of astragaloside IV (ASI) on the activation of microglial cells.</p><p><b>METHOD</b>After pre-incubated with ASI for 2 h, microglial cells BV-2 were stimulated with interferon-γ (IFN-γ) for 1. 5 h and 24 h, respectively. Secretion of nitric oxide (NO) in the medium was measured by Griess method. Production of tumor necrosis factor alpha (TNF-α) was detected by ELISA approach. Cellular gene expressions of CD11b, TNF-α, interleukin 1β (IL-1β) and induced nitric oxide synthase (iNOS) were examined by quantitative-PCR analysis. Total and phosphorylation of STAT1, IκB and NF-κB was analyzed by Western blot method.</p><p><b>RESULT</b>ASI could significantly inhibit the increased secretion of TNF-α and NO from BV-2 cells upon IFN-γ stimulation (P < 0.001). Further study showed that ASI significantly down-regulated gene expression of IL-1β and TNF-α (P < 0.01, P < 0.05) and exhibited a trend to reduce that of iNOS. IFN-γ and ASI have no obvious effect on gene expression of CD11b. Moreover, ASI inhibited the phosphorylation of STAT1, IκB and NF-κB elicited by IFN-γ stimulation.</p><p><b>CONCLUSION</b>ASI could restrain microglial activation through interfering STAT1/IκB/NF-κB signaling pathway, reducing gene expres- sion of IL-1β and TNF-α, and thus inhibiting the production of proinflammatory mediators such as NO and TNF-α.</p>

Cisplatin inhibits proliferation of cervical carcinoma cell line by up-regulating Stat1 expression / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the role of Stat1 gene in the proliferation and chemotherapeutic sensitivity of cervical cancer HeLa cells.</p><p><b>METHODS</b>The protein expression of Stat1 in the Hela cells exposed to gradient concentrations of cisplatin (DDP) was detected by Western blotting with or without small interfering RNA (siRNA)-mediated Stat1 gene silencing. The effect of Sata1 silencing on the sensitivity to DDP and cell proliferation of the cells was tested using MTT assay and BrdU assay, and the expression of c-Myc was detected by Western blotting in the cells treated with siRNA and DDP.</p><p><b>RESULTS</b>The expression of Stat1 in Hela cells exposed to DDP increased with the DDP concentrations, reaching 1.5 folds of the baseline at a DDP concentration of 5 mg/L and 2 folds at 10 mg/L. Stat1-siRNA effectively reduced Stat1 expression in Hela cells, promoted the cell proliferation, and enhanced the expression of c-Myc; DDP inhibited the cell growth and down-regulated c-Myc expression. Stat1-siRNA rescued DDP-induced inhibition of cell growth and c-Myc down-regulation.</p><p><b>CONCLUSION</b>The expression of Stat1 is associated with DDP sensitivity in cervical cancer cells, and Stat1 silencing can increase the sensitivity to DDP and c-Myc expression of the cells.</p>

Dual role of daphnetin in suppressing HMGB1 release and HMGB1-induced inflammation in murine macrophage RAW264.7 cells and human monocytic THP-1 cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the dual role of daphnetin in suppressing high mobility group box-1 protein (HMGB1) release and blocking HMGB1-induced inflammatory response.</p><p><b>METHODS</b>Murine macrophage RAW264.7 cells were cultured in the presence of daphnetin, lipopolysaccharide (LPS), or both. HMGB1 release from the cells was determined using ELISA, and phosphorylations of JAK1/2 and of STAT1 were detected by Western blotting. Human monocytic THP-1 cells exposed to daphnetin, rhHMGB1, or both were examined for NO production using a NO detection kit, for the release of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and prostaglandin E2 (PGE2) using ELISA, and for expressions of iNOS, COX-2 and phosphorylated p38, ERK, and JNK with Western blotting.</p><p><b>RESULTS</b>Daphnetin dose-dependently reduced the release of HMGB1 in RAW264.7 cells and suppressed rhHMGB1-induced iNOS and COX-2 expressions and release of TNF-α, IL-6, PGE2, and NO in THP-1 cells. Western blotting revealed that daphnetin significantly down-regulated the phosphorylations of JAK-STAT1 pathway in LPS-stimulated RAW264.7 cells but did not suppress the phosphorylations of MAPKs signaling pathway induced by rhHMGB1 in THP-1 cells.</p><p><b>CONCLUSION</b>Daphnetin can reduce the release of HMGB1 and suppress HMGB1-induced inflammatory response. In RAW264.7 cells, daphnetin inhibited LPS induced HMGB1 release is at least partly mediated by suppressing JAK-STAT1 signaling pathway activation.</p>

Tanshinone attenuates myocardial injury via activating JAK2/STAT1 pathway in a murine model of viral myocarditis / 中华心血管病杂志

<p><b>OBJECTIVE</b>To explore the effects of tanshinone and JAK2/STAT1 signaling pathway related mechanism in CVB3-induced myocarditis in murine.</p><p><b>METHODS</b>A total of 110 inbred male Balb/c mice which were 4 to 6 weeks-old were randomly divided into five groups: normal control (N, n = 10), myocarditis control (C, n = 25), tanshinone group (T, 15 mg · kg⁻¹ · d⁻¹, i.p., n = 25), janus kinase 2 inhibitor AG490 group (A, 10 mg · kg⁻¹ · d⁻¹, i.p., n = 25), T+A group (H, n = 25). Myocarditis was induced by 0.5 ml 10(-9.51) TCID50/ml CVB3 i.p. injection for 10 days in group C, T and H. Myocardial histopathologic changes were observed and phospho-STAT1 expressions were detected by immunohistochemistry and Western blot analysis. The levels of serum cardiac troponin I were detected with chemiluminescence immunoassay.</p><p><b>RESULTS</b>(1) Compared with group C, the histopathologic scores were significantly higher in group A and H (3.35 ± 0.57 and 3.34 ± 0.54 vs. 2.12 ± 0.39, P < 0.01), but lower in group T (1.40 ± 0.34 vs.2.12 ± 0.39, P < 0.01). (2) The expression of p-STAT1 protein was similar in group A and H compared to group N (P > 0.05), but was significantly lower than that in group C (0.017 ± 0.010 and 0.020 ± 0.010 vs. 0.246 ± 0.010, P < 0.01). The expression of p-STAT1 protein was significantly higher in group T than in group C (P < 0.01). (3) The levels of serum cardiac troponin I in group C, A, T and H were significantly higher than in group N ((0.42 ± 0.06), (1.17 ± 0.25), (0.23 ± 0.05) and (1.04 ± 0.19) µg/L vs. (0.02 ± 0.01) µg/L, all P < 0.01). The levels of serum cardiac troponin I were significantly higher in group A and H compared with group C ((1.17 ± 0.25) and (1.04 ± 0.19) µg/L vs. (0.42 ± 0.06) µg/L, P < 0.01), but were significantly lower in group T than in group C ((0.23 ± 0.05) µg/L vs. (0.42 ± 0.06) µg/L, P < 0.01). (4) There was a negative correlation between the expression level of p-STAT1 and the histopathologic scores (y = -4.503 x + 3.371, R² = 0.738, P < 0.01), but a positive correlation between the levels of serum cardiac troponin I and the histopathologic scores (y = 1.935x + 1.165, R² = 0.766, P < 0.01).</p><p><b>CONCLUSION</b>Tanshinone could attenuate myocardial injury via upregulating the JAK2/STAT1 signaling pathway in this murine viral myocarditis model.</p>

STAT signaling pathway mediates high glucose induced cardiac fibroblasts proliferation and collagen deposition in vitro / 中华心血管病杂志

<p><b>OBJECTIVE</b>To observe the signal transducers and activator of transcriptions (STATs) protein expression changes and investigate the functional role of STATs pathway in case of high glucose-induced cardiac fibroblasts (CFs) proliferation and collagen deposition in vitro.</p><p><b>METHODS</b>Rat cardiac fibroblasts were isolated from 1- to 3-day-old SD rats, cells from the second to fourth passages were used for the experiment. CFs were cultured in Dulbecco's modified Eagle's medium, supplemented with 5.5 mmol/L glucose (NG), 5.5 mmol/L glucose plus 19.4 mmol/L mannose (OC) or 25 mmol/L glucose (HG) in the presence of absence of STAT1 inhibitor (fludarabine, FLU) and STAT3 inhibitor (S3I-201). After 24 h and 48 h culture in vitro, the proliferation of CFs was measured by 3-(4,5-dimethyl-2 thiazoyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. After 12 h and 24 h culture in vitro, the production of type I and III collagen was evaluated using real-time quantitative PCR and ELISA. After 0, 30, 60 and 120 min culture in vitro, the phosphorylated expression of STAT1 and STAT3 was analyzed by Western blot.</p><p><b>RESULTS</b>CFs proliferation was significantly enhanced post 24 h and 48 h HG stimulation, and procollagen I and III mRNA expression was significantly upregulated post 12 h and 24 h HG stimulation. Deposition of collagen I and III was also significantly increased post 24 h and 72 h HG stimulation. STAT1 phosphorylation in CFs was increased after 120 min HG stimulation and STAT3 phosphorylation in CFs was increased post 60 min and 120 min HG stimulation. FLU and S3I-201 could inhibit HG-induced CFs proliferation and suppress of which was stimulated by FLU and S3I-201 could both suppress upregulated procollagen I and III mRNA expression and the deposition of collagen types I and III post HG stimulation. STAT1 phosphorylation inhibition resulted in less mRNA downregulation of procollagen type III than that of procollagen type I post 12 h HG stimulation. The STAT3 phosphorylation inhibition resulted in more significantly upregulated procollagen type III mRNA expression than procollagen type I mRNA expression at 12 h post HG stimulation.</p><p><b>CONCLUSION</b>HG could enhance the protein expression of phosphorylated STAT1 and STAT3 in CFs, which are responsible for HG-induced increased CFs proliferation and collagen deposition in vitro.</p>

Infection-stimulated anemia results primarily from interferon gamma-dependent, signal transducer and activator of transcription 1-independent red cell loss / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Although the onset of anemia during infectious disease is commonly correlated with production of inflammatory cytokines, the mechanisms by which cytokines induce anemia are poorly defined. This study focused on the mechanism research.</p><p><b>METHODS</b>Different types of mice were infected perorally with Toxoplasma gondii strain ME49. At the indicated times, samples from each mouse were harvested, processed, and analyzed individually. Blood samples were analyzed using a Coulter Counter and red blood cell (RBC) survival was measured by biotinylation. Levels of tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS), and inducible protein 10 (IP-10) mRNA in liver tissue were measured by real-time polymerase chain reaction.</p><p><b>RESULTS</b>T. gondii-infected mice exhibited anemia due to a decrease in both erythropoiesis and survival time of RBC in the circulation (P < 0.02). In addition, infection-stimulated anemia was associated with fecal occult, supporting previous literature that hemorrhage is a consequence of T. gondii infection in mice. Infection-induced anemia was abolished in interferon gamma (IFNγ) and IFNγ receptor deficient mice (P < 0.05) but was still evident in mice lacking TNF-α, iNOS, phagocyte NADPH oxidase or IP-10 (P < 0.02). Neither signal transducer and activator of transcription 1 (STAT1) deficient mice nor 129S6 controls exhibited decreased erythropoiesis, but rather suffered from an anemia resulting solely from increased loss of circulating RBC.</p><p><b>CONCLUSIONS</b>Infection-stimulated decrease in erythropoiesis and losses of RBC have distinct mechanistic bases. These results show that during T. gondii infection, IFNγ is responsible for an anemia that results from both a decrease in erythropoiesis and a STAT1 independent loss of circulating RBC.</p>