Signal Transducer And Activator Of Transcription 3 Gene Research Articles

CRISPR/Cas9-mediated knockout of STAT1 in porcine-derived cell lines to elucidate the role of STAT1 in autophagy following classical swine fever virus infection

Signal transducer and activator of transcription 1 (STAT1) plays a critical role in immune response, human STAT1 as a transcriptional suppressor of autophagy genes and autophagic activity. Classical swine fever virus (CSFV)-infected induce autophagy, leading to immune evasion. However, there are limited reports on the function of porcine STAT1 in autophagy during CSFV infection. There is also lack of suitable in vitro models for studying porcine STAT1. The objective of this study was to establish porcine PK-15 STAT1-/- and 3D4/21 STAT1-/- cell lines using the CRISPR/Cas9 system to investigate the function of the STAT1 in autophagy. The PK-15STAT1-/- and 3D4/21STAT1-/- cell lines, featuring homozygous knockout of STAT1 gene were successfully constructed using the CRISPR/Cas9 editing system. The knockout efficiency determined to be 82.4% and 81.1%, respectively. Infection with CSFV in porcine PK-15STAT1-/- and 3D4/21STAT1-/- cells led to an observable increase in autophagosomes as evidenced by transmission electron microscope. Additionally, STAT1 knockout (STAT1-/-) by the CRISPR/Cas9 system upregulated the expression of ULK1, Beclin1, and LC3 genes, thereby enhancing autophagy during CSFV infection. Conversely, overexpression of STAT1 downregulated the expression of ULK1, Beclin1, and LC3 genes, leading to inhibition of autophagy during CSFV infection.The application of an autophagy dual-fluorescent-tracking plasmid demonstrated that STAT1 knockout enhanced autophagy accumulation during CSFV infection, while STAT1 overexpression inhibited it. Moreover, the 3D4/21STAT1-/- cell line proved to be a more suitable in vitro model compared to the PK-15STAT1-/- cell line for elucidating the involvement of STAT1 in autophagy during CSFV infection.

Renal Solitary Fibrous Tumor With Müllerian Cysts: A Novel Differential Diagnosis for Biphasic Renal Neoplasms.

Solitary fibrous tumor is an uncommon mesenchymal neoplasm, initially described in the pleura and infrequently found in the kidney. It is characterized by haphazardly arranged spindle cells, staghorn vasculature, coexpression of CD34 and signal transducer and activator of transcription 6 (STAT6), and a NAB2::STAT6 gene fusion. We report a 64-year-old woman who presented with a 2.5 cm multilocular cystic renal mass. On microscopic examination, the tumor consisted of a spindle cell component closely intermingled with ciliated and hemorrhagic epithelial cysts. The spindle cell component was positive for CD34, B-cell lymphoma 2 (BCL2), and STAT6, confirming the diagnosis of a solitary fibrous tumor. The epithelial cysts expressed keratin 7, PAX8, BCL2, estrogen receptor 1, and progesterone receptor, indicative of Müllerian cysts. The occurrence of solitary fibrous tumor in the kidney is extremely rare, and its association with Müllerian cysts has not been previously reported in the kidney. This morphologic variant has a striking similarity with biphasic renal neoplasms, especially with mixed epithelial and stromal tumors and angiomyolipoma with epithelial cysts. This report describes a novel renal solitary fibrous tumor subtype within this differential and underscores clinical and pathological distinctions of biphasic renal neoplasms.

Exploring Natural Compounds Targeting PD-L1 and STAT3: Toxicogenomic Analysis, Virtual Screening, Molecular Docking, ADMET Evaluation, and Biological Activity Prediction.

One of the most important targets in cancer immunotherapy is programmed cell death ligand 1 (PD-L1). Monoclonal antibodies developed for this target have disadvantages due to their low bioavailability and some immune-related adverse effects. Additionally, small molecules targeting PD-L1 are still in the experimental stage. At this point, discovering non-toxic natural compounds that directly or indirectly target PD-L1 is essential. In this in silico study, a comprehensive literature search was conducted to identify publications reporting the master regulator of PD-L1, which was suggested as a Signal Transducer and Activator of Transcription 3 (STAT3). The relationship between STAT3 and PD-L1 was further investigated through bioinformatic analysis. Subsequently, natural compounds targeting PD-L1 and STAT3 were screened, and compounds with suitable toxicity profiles were docked against both PD-L1 and STAT3. Following molecular docking, the selected molecules underwent DNA docking, ADMET profile analysis, and in silico assessment of biological activities. The relationship between PD-L1 and STAT3 was determined in 52 out of the 453 articles, and it was further demonstrated in genegene interactions. Following the virtual screening, 76 natural compounds were identified, and after pre-filtering based on physicochemical properties, drug-likeness, and ADMET profiles, 29 compounds remained. Subsequent docking revealed that two compounds, 6-Prenylapigenin, and Gelomulide J, persisted. ADMET and biological activity prediction results suggested that 6-Prenylapigenin is non-toxic and has the potential to inhibit PD-L1 and STAT3 in silico. The present study highlights that STAT3 serves as the master regulator of PD-L1, and it further suggests that 6- Prenylapigenin exhibits the potential to modulate PD-L1 and/or STAT3. This finding could pave the way for the development of small molecules designed to block the PD-1/PD-L1 interaction by silencing the PD-L1 and/or STAT3 genes or reducing protein levels.

Association between STAT4 gene polymorphism and susceptibility to pulmonary tuberculosis in the Moldavian population.

Signal transducer and activator of transcription 4 (STAT4) plays a crucial role in the host immune response against Mycobacterium tuberculosis. This study investigates the association between STAT4 gene polymorphisms and pulmonary tuberculosis (TB) risk in the Moldavian population. A total of 272 TB patients and 251 community-matched controls underwent screening for functional single-nucleotide polymorphisms (SNPs) rs897200 and rs7574865 in the STAT4 gene. The minor T allele and the TT/CT genotype of rs897200 demonstrated a significant association with reduced pulmonary TB risk (allelic model: adjusted OR=.74, p=.025; log-additive model: adjusted OR=.72, p=.02; and dominant model: adjusted OR=.65, p=.023), indicating a protective effect. Similar associations, characterized by an even more pronounced reduction in risk, were observed among females and late-onset TB patients (>44 years). No significant associations were found for rs7574865. In addition, a combined genotype analysis incorporating 43 SNPs from our previous studies revealed potential associations, such as STAT4 rs897200 CT with IFNG rs2430561 AA (adjusted OR=.36, p=.0025) and STAT4 rs897200 CT with TNFA rs1800629 GA (adjusted OR=.33, p=.0012). This study emphasizes the significant association of STAT4 rs897200 with pulmonary TB risk in the Moldavian population, underscoring its role in the disease development.

Influence of STAT4 Genetic Variants and Serum Levels on Multiple Sclerosis Occurrence in the Lithuanian Population.

Background: Multiple sclerosis (MS) is an autoimmune disease involving demyelination, inflammation, gliosis, and the loss of neurons. MS is a growing global health problem most likely caused by genetic, immunological, and environmental factors. However, the exact etiology of the disease is still unknown. Since MS is related to a dysregulation of the immune system, it could be linked to signal transducer and activator of transcription 4 (STAT4). To fully comprehend the significance of the STAT4 gene and STAT4 serum levels in MS, further research is required. Methods: A total of 200 MS patients and 200 healthy controls participated in the study. Deoxyribonucleic acid (DNA) was extracted using silica-based membrane technology. Polymerase chain reaction was used in real time for genotyping. Using the ELISA technique, serum levels were measured. Results:STAT4 rs7601754 AA genotype and the A allele were statistically significantly less frequent in MS patients (p = 0.003). Also, rs7601754 was associated with 1.9-fold increased odds of MS occurrence (p = 0.004). The rs7601754 AG genotype was more common in males with MS (p = 0.011) and was associated with 2.5-fold increased odds of MS occurrence in males (p = 0.012). STAT4 serum levels were statistically significantly lower in MS patients compared to the control group (p = 0.007). Conclusions:STAT4 rs7601754 increases the odds of MS occurrence. STAT4 serum levels were statistically significantly lower in MS patients compared to the control group.

Molecular confirmation and functional study of signal transducer and activator of transcription genes in the Pacific oyster Crassostrea gigas

The JAK (Janus kinase)-STAT (Signal transducer and activator of transcription) is a well-known functional signaling pathway that plays a key role in several important biological activities such as apoptosis, cell proliferation, differentiation, and immunity. However, limited studies have explored the functions of STAT genes in invertebrates. In the present study, the gene sequences of two STAT genes from the Pacific oyster (Crassostrea gigas), termed CgSTAT-Like-1 (CgSTAT-L1) and CgSTAT-Like-2 (CgSTAT-L2), were obtained using polymerase chain reaction (PCR) amplification and cloning. Multiple sequence comparisons revealed that the sequences of crucial domains of these proteins were conserved, and the similarity with the protein sequence of other molluscan STAT is close to 90 %. The phylogenetic analyses indicated that CgSTAT-L1 and CgSTAT-L2 are novel members of the mollusk STAT family. Quantitative real-time PCR results implied that CgSTAT-L1 and CgSTAT-L2 mRNA expression was found in all tissues, and significantly induced after challenge with lipopolysaccharide (LPS), peptidoglycan (PGN), or poly(I:C). After that, dual-luciferase reporter assays denoted that overexpression of CgSTAT-L1 and CgSTAT-L2 significantly activated the NF-κB signaling, and, interestingly, the overexpressed CgSTAT proteins potentiated LPS-induced NF-κB activation. These results contributed a preliminary analysis of the immune-related function of STAT genes in oysters, laying the foundation for deeper understanding of the function of invertebrate STAT genes.

Abstract B037: Utilizing GSK3β and integrin inhibitors to target STAT3 activity in triple negative breast cancer

Abstract Triple negative breast cancer (TNBC) is the most aggressive subtype of breast cancer known for its high rate of recurrence and metastatic ability. Patients face a poor prognosis and the five-year survival rate for those diagnosed with metastatic TNBC is very low. The transcription factor Signal Transducer and Activator of Transcription 3 (STAT3) is constitutively active in TNBC and functions to promote proliferation and metastasis. Therefore, it is a potential therapeutic target for TNBC. We used CLUE, an online bioinformatics tool from the Broad Institute, to identify potential STAT3 inhibitors. To do this, a STAT3 gene signature generated from TNBC cells was used to query the gene signatures from drug treatments in the CLUE dataset for compounds that caused a similar signature. The hypothesis is that a drug with a similar signature to the STAT3 inhibition signature would be a potential STAT3 inhibitor. Drugs were chosen based on high similarity rating and known function. One of the top drugs we chose to pursue was TWS-119, a GSK3β inhibitor. GSK3β is a serine/threonine kinase that regulates proliferation and cell survival. TWS-119 was found to decrease the viability of MDA-MB-231, MDA-MB-468, and Hs587T TNBC cell lines. To assess the ability of TWS-119 to inhibit STAT3 activity, we used a STAT3 responsive reporter and found that TWS-119 inhibited STAT3 activity in MDA-MB-468 cells. To determine the mechanism of inhibition of STAT3 activity, we analyzed the effects of TWS-119 on STAT3 tyrosine phosphorylation. Preliminary results suggest that TWS-119 inhibits STAT3 activity via inhibition of tyrosine phosphorylation. Having determined that TWS-119 inhibited STAT3 activity, we wanted to determine if TWS-119 had any effect on TNBC migration. We found that TWS-119 reduced the migratory ability of MDA-MB-231 cells. An additional drug identified from CLUE was Cilengitide, an inhibitor of integrin ⍺vβ3 which plays an important role in proliferation and migration. While Cilengitide only slightly decreased the viability of the three different TNBC cell lines (MDA-MB-231, MDA-MB-468, Hs587T), we found that combinations of Cilengitide and TWS-119 had synergistic effects on cell viability in the TNBC cells. Preliminary western blot analysis demonstrated that the combination of both drugs reduced the level of pY-STAT3. This suggests that this combination targeting STAT3 may be a viable treatment strategy for TNBC. However, the mechanism through which these drugs interact is unknown, and the cell signaling relationship between their known targets (GSK3β and integrin ⍺vβ3) and STAT3 is unclear. We are currently working to define the mechanism of action of these combination effects in TNBC cells. Using TWS-119 and Cilengitide, we can determine the connection between integrins, GSK3β, and STAT3 to better understand proliferation and metastasis and to identify new therapeutic options for TNBC patients. Citation Format: Emily A Pratt, Sarah R Walker. Utilizing GSK3β and integrin inhibitors to target STAT3 activity in triple negative breast cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Breast Cancer Research; 2023 Oct 19-22; San Diego, California. Philadelphia (PA): AACR; Cancer Res 2024;84(3 Suppl_1):Abstract nr B037.

Inhibition of STAT3 alleviates LPS-induced apoptosis and inflammation in renal tubular epithelial cells by transcriptionally down-regulating TASL

BackgroundSystemic lupus erythematosus (SLE) is a common autoimmune disease that impacts various organs. Lupus nephritis (LN) significantly contributes to death in children with SLE. Toll-like receptor (TLR) adaptor interacting with SLC15A4 on the lysosome (TASL) acts as an innate immune adaptor for TLR and is implicated in the pathogenesis of SLE. A transcription factor known as signal transducer and activator of transcription 3 (STAT3), which is known to be linked to autoimmune diseases, is also involved in the development of SLE.MethodsBioinformatics and real-time quantitative PCR (qRT-PCR) was used to detect the expression of STAT3 and TASL in peripheral blood of SLE patients and their correlation. Bioinformatics analysis, qRT-PCR, luciferase assay and chromatin immunoprecipitation (ChIP) were used to verify the regulation of transcription factor STAT3 on TASL. The expression levels of STAT3, TASL and apoptosis-related genes in LPS-induced HK2 cells were detected by qRT-PCR and Western blot. TUNEL staining were used to detect the apoptosis of HK2 cells after LPS stimulation. ELISA and qRT-PCR were used to detect the levels of inflammatory cytokines in the cell culture supernatant. TASL knockdown in HK2 cells was used to detect the changes in apoptosis-related genes and inflammatory factors. The expression level of TASL in LPS-stimulated HK2 cells and its effect on cell apoptosis and inflammatory factors were observed by knocking down and overexpressing STAT3, respectively. It was also verified in a rescue experiment.ResultsThe expressions of STAT3 and TASL were higher in SLE than in healthy children, and the expression of STAT3 was positively correlated with TASL. Transcription factor STAT3 can directly and positively regulate the expression of TASL through the promoter region binding site. The expression of STAT3, TASL and inflammatory cytokines was elevated, and the change of apoptosis was up-regulated in LPS-stimulated HK2 cells. Inhibition of STAT3 alleviates LPS-stimulated apoptosis and inflammatory response in HK2 cells through transcriptional regulation of TASL.ConclusionsThese findings provide new insights into the transcriptional regulation of TASL and provide new evidence of a direct regulatory relationship between signaling nodes in the lupus signaling network.Graphical

STAT3 drives the malignant progression of low-grade gliomas through modulating the expression of STAT1, FOXO1, and MYC.

Low-grade glioma (LGG) is a prevalent and lethal primary brain malignancy, with most patients succumbing to recurrence and progression. The signal transducer and activator of transcription (STAT) family has long been implicated in tumor initiation and progression. However, a comprehensive evaluation of the expression status and overall function of STAT genes in LGG remains largely unreported. In this study, we investigated the association between the expression of STAT family genes and the progression of LGG. Through a comprehensive analysis that combined bioinformatics screening and validation assays, we determined that STAT1, STAT3, and STAT5A were upregulated and contributed to the malignant progression of LGG. Notably, our findings suggest that STAT3 is a critical prognostic marker that regulates the progression of LGG. STAT3 emerged as the most significant prognostic indicator governing the advancement of LGG. Additionally, our inquiry into the STAT3-binding proteins and differentially expressed-correlated genes (DEGs) revealed that STAT3 played a pivotal role in the progression of LGG by stimulating the expression of STAT1, FOXO1, and MYC. In summary, our recent study conducted a thorough analysis of the STAT family genes and revealed that directing therapeutic interventions towards STAT3 holds potential as a viable strategy for treating patients with LGG.

Membrane-proximal motifs encode differences in signaling strength between type I and III interferon receptors.

Interferons (IFNs) play crucial roles in antiviral defenses. Despite using the same Janus-activated kinase (JAK)-signal transducer and activator of transcription (STAT) signaling cascade, type I and III IFN receptors differ in the magnitude and dynamics of their signaling in terms of STAT phosphorylation, gene transcription, and antiviral responses. These differences are not due to ligand-binding affinity and receptor abundance. Here, we investigated the ability of the intracellular domains (ICDs) of IFN receptors to differentiate between type I and III IFN signaling. We engineered synthetic, heterodimeric type I and III IFN receptors that were stably expressed at similar amounts in human cells and responded to a common ligand. We found that our synthetic type I IFN receptors stimulated STAT phosphorylation and gene expression to greater extents than did the corresponding type III IFN receptors. Furthermore, we identified short "box motifs" within ICDs that bind to JAK1 that were sufficient to encode differences between the type I and III IFN receptors. Together, our results indicate that specific regions within the ICDs of IFN receptor subunits encode different downstream signaling strengths that enable type I and III IFN receptors to produce distinct signaling outcomes.

Resistance Improvement and Sensitivity Enhancement of Cancer Therapy by a Novel Antitumor Candidate onto A2780 CP and A2780 S Cell Lines.

To overcome cisplatin resistance, the cytotoxicity of a novel antitumor agent on two ovarian cancer cell lines sensitive and resistant to cisplatin was investigated. MTT assay and flow cytometry were performed to assess the cytotoxicity of a novel water-soluble Pd (II) complex, [Pd(bpy)(pyr-dtc)]NO3 (PBPD), on cisplatin-sensitive and cisplatin-resistant ovarian cancer cell lines. Furthermore, variations in the expression of drug resistance gene cluster of differentiation 99 (CD99), signal transducer and activator of transcription 3 (STAT3), octamer-binding transcription factor 4 (OCT4), and multidrug resistance mutation 1 (MDR1) were evaluated using Real-Time PCR. The IC50 values of PBPD in resistant cells were higher than those in sensitive cells. Furthermore, PBPD has a deadlier effect on sensitive cells compared to resistant cells, and the cell survival rate is reduced over time. Flow cytometry revealed that PBPD enhanced the population of living-resistant cells while driving them to apoptosis. PBPD, on the other hand, has a greater effect on the living cell population and has dramatically shifted the population toward apoptosis and necrosis in the sensitive cells. Furthermore, gene expression analysis showed that when sensitive and resistant cells were treated with cisplatin, all resistance genes increased significantly relative to the control. In contrast to OCT4, MDR1, STAT3, and CD99 resistance genes were not significantly elevated in sensitive cells treated with PBPD compared to the control. Thus, the expression of resistance genes in resistant cells treated with PBPD was lower than cisplatin. As a result, PBPD is a promising anticancer agent for CDDP-resistant ovarian cancer.

Interplay between signal transducers and activators of transcription (STAT) proteins and cancer: involvement, therapeutic and prognostic perspective.

Signal transducers and activators of transcription or STAT are proteins that consist of various transcription factors that are responsible for activating genes regarding cell proliferation, differentiation, and apoptosis. They commonly activate several cytokine, growth, or hormone factors via the JAK-STAT signaling pathway by tyrosine phosphorylation which are responsible for giving rise to numerous immune responses. Mutations within the Janus-Kinases (JAKs) or the STATs can set off the commencement of various malfunctions of the immune system of the body; carcinogenesis being an inevitable outcome. STATs are known to act as both oncogenes and tumor suppressor genes which makes it a hot topic of investigation. Various STATs related mechanisms are currently being investigated to analyze its potential of serving as a therapeutic base for numerous immune diseases and cancer; a deeper understanding of the molecular mechanisms involved in the signaling pathways can contribute to the same. This review will throw light upon each STAT member in causing cancer malignancies by affecting subsequent signaling pathways and its genetic and epigenetic associations as well as various inhibitors that could be used to target these pathways thereby devising new treatment options. The review will also focus upon the therapeutic advances made in cancers that most commonly affect people and discuss how STAT genes are identified as prognostic markers.

The association of Sirtuin1 (SIRT1) polymorphism and downregulation of STAT4 gene expression with increased susceptibility to COVID-19 infection

ABSTRACT Sirtuin1 (SIRT1) is an epigenetic modulator that belongs to sirtuins family and participates in many physiologic reactions, as genomic stabilization, apoptosis, proliferation, and inflammation. STAT4 (signal transducer and activator of transcription 4) gene is a component of JAK-STAT signaling pathway, which plays key role in activating cellular-mediated immune responses. The present study aimed to investigate the association between SIRT1 rs12778366 SNP, expression level of STAT4 gene and susceptibility to COVID-19 infections as well as their correlation to clinicopathological data. The present study included 100 ICU patients with severe COVID-19 infection and 100 age- and sex-matched healthy controls. DNA was extracted. Genotyping of SNP in SIRT1 (rs12778366) was performed, Total RNA was extracted from PBMCs. Reverse transcription was done. STAT4 gene expression levels were evaluated with GAPDH as internal control using real-time PCR. We found a significantly higher frequency of ‘C’ allele and C/T genotype in case vs. control. The association was of low strength (φ = 0.105 for alleles, and 0.154 for genotypes). This was associated with higher expression of STAT4 gene (P < 0.001) and increased tendency for lower respiratory complications. Median STAT4 (FC) (Median = 0.18, 95% CI = 0.15–0.27) was lower than normal control value of 1.0. This difference was statistically significant (Hodges-Lehmann location estimator = 0.217, P < 0.001). SIRT1 polymorphism and decreased expression of STAT4 gene are associated with increased susceptibility to COVID-19 infection and correlate to its phenotypic manifestations.

Response to treatment of murine schistosomiasis with recombinant IL-22 under different circadian timing

ABSTRACT Response to treatment usually depends on the time of drug administration. Interleukin-22 (IL-22) is known for its protective effect against liver injury. Therefore, the aim was to study the effectiveness of the IL-22 treatment at different circadian timing on S. mansoni-infected mice. Mice grouping included; control group, mice infected with cercariae, and IL-22-treated groups. Treatment with IL-22 (0.36 µg/kg) was performed on infected mice either at 7 am, or 7 pm. Hepatic granuloma index (GI), levels of tumor necrosis factor-α (TNF-α), interleukin-17 (IL-17), IL-22, and immunoglobulin E (IgE) were measured. In addition, hepatic expressions of signal transducer and activator of transcription 3 (STAT3) and β-catenin genes were estimated. Infection with S. mansoni increased pro-inflammatory parameters, STAT3, and β-catenin mRNA significantly (P < 0.05) compared to the control group. IL-22 groups showed a significant reduction (P < 0.05) in liver GI, TNF-α, and β-catenin mRNA compared to infected mice. Moreover, it enhanced STAT3 gene expression (P < 0.05). IL-22 administration at 7 am reduced GI, IL-17, and IgE levels significantly (P < 0.05) compared to 7 pm values. The conclusion, IL-22 might have an immunotherapeutic effect. Its administration at 7 am was more effective in reducing hepatic granuloma and IgE, but further studies are needed to support these findings.

STAT1/MUC4 activation promotes antimicrobial peptide production to reduce intestinal epithelium barrier injury caused by enteropathogenic Escherichia coli infection

IntroductionAntimicrobial peptides (AMPs) are endogenous peptides that have been identified to alleviate intestinal epithelial barrier inflammation and dysfunction caused by enteropathogenic Escherichia coli (EPEC) infection; nonetheless, the upstream molecular mechanism of the production of AMPs is poorly understood.Material and methodsThe binding of signal transducer and activator of transcription (STAT) 1 (STAT1) to mucin 4 (MUC4) was examined by Co-Immunoprecipitation assay. To detect the influence of STAT1 and MUC4 expression, C57BL/6 mice model of EPEC infection in vivo and EPEC infected intestinal epithelial cells (IEC) in vitro model was established. Expressions of STAT1, MUC4, phosphorylated (p)-STAT1, proinflammatory cytokines, zonula occludens-1 (ZO-1) and AMP-related genes in mouse ileum and/or IEC were analyzed by immunohistochemical test, immunofluorescence assay, Western blot, and/or qRT-PCR. Meanwhile, IEC viability and apoptosis were measured using CCK-8 assay and flow cytometry.Resultsp-STAT1, MUC4, ZO-1 and AMP-related gene were lowly expressed in the ileum of EPEC-infected mice. p-STAT1 and MUC4 bound to each other. The expressions of STAT1 and MUC4 were decreased in EPEC-infected IEC. Overexpression of STAT1 resisted EPEC-induced viability decrease, apoptosis promotion, ZO-1 activity inhibition, release of proinflammatory cytokines, and downregulation of MUC4 and AMP-related genes in IEC. MUC4 knockdown partly counteracted the effect of STAT1 overexpression, but did not affect the forced STAT1 overexpression in EPEC-infected IEC.ConclusionsSTAT1/MUC4 pathway activation promotes AMP production to mitigate intestinal epithelium barrier injury caused by EPEC infection.

A rare mutation causing autosomal dominant STAT1 deficiency in a South African multiplex kindred with disseminated BCG infection

BackgroundAutosomal dominant signal transducer and activator of transcription 1 (STAT1) deficiency, part of the Mendelian susceptibility to mycobacterial disease (MSMD) group, frequently causes disseminated Bacillus Calmette-Guérin (BCG) infections, but has not been reported from Sub-Saharan Africa (SSA) where routine birth BCG vaccination is practiced.Case presentationTwo half-siblings presented five years apart, with multifocal osteomyelitis as the dominant feature of disseminated BCG, which was successfully treated with antimycobacterial therapy. Whole exome sequencing demonstrated a novel heterozygous substitution in the splice site between intron 13 and exon 14 of the STAT1 gene, NM_007315: c.1128-1G>A, in the proband and his mother and was later confirmed in his half-brother.ConclusionsChildren with BCG vaccine complications in SSA should be referred for further investigation and particular consideration of MSMD.

Characterization of Japanese flounder (Paralichthys olivaceus) STAT members: An immune-related gene family involved in Edwardsiella tarda and temperature stress.

The signal transducer and activator of transcription (STAT) family members are not only the transcriptional activators, but also play important roles in regulating inflammatory response. Some members have been reported to be involved in innate bacterial and antiviral immunity in aquatic organisms. However, no systematic research on STATs has been found in teleost. In this present study, we characterized six STAT genes in Japanese flounder based on bioinformatics methods, namely PoSTAT1, PoSTAT2, PoSTAT3, PoSTAT4, PoSTAT5 and PoSTAT6. The phylogenetic analysis of STATs in fish indicated that STATs were highly conserved and revealed an absence of STAT5 in a few species. Further analysis of gene structures and motifs showed STAT proteins shared a similar structure and probably had similar functionality in Japanese flounder. The expression profiles of different development stages and tissues demonstrated that PoSTATs exhibited specificity in temporality and spatiality as well as PoSTAT4 was highly expressed in gill. The transcriptome data analysis of E. tarda and temperature stress showed that PoSTAT1 and PoSTAT2 were more respective to these two kinds of stress. In addition, the results also demonstrated that these PoSTATs might regulate immune response in different ways, manifested by up-regulation in E. tarda infection and down-regulation in temperature stress. In a word, this systematic analysis of PoSTATs would provide valuable information about the phylogenetic relationship of STATs in fish species and help understand the role of STAT genes in the immune response of Japanese flounder.

Novel mutations in genes of the IL-12/IFN-γ axis cause susceptibility to tuberculosis

BackgroundThe IL-12/23/ISG15-IFN-γ pathway is the main immunological pathway for controlling intra-macrophagic microorganisms such as Mycobacteria, Salmonella, and Leishmania spp. Consequently, upon mutations in genes of the IL-12/23/ISG15-IFN-γ pathway cause increased susceptibility to intra-macrophagic pathogens, particularly to Mycobacteria. Therefore, the purpose of this study was to characterize the mutations in genes of the IL-12/23/ISG15-IFN-γ pathway in severe tuberculosis (TB) patients. MethodsClinically suspected TB was initially confirmed in four patients (P) (P1, P2, P3, and P4) using the GeneXpert MTB/RIF and culturing techniques. The patients' Peripheral blood mononuclear cells (PBMCs) were then subjected to ELISA to measure Interleukin 12 (IL-12) and interferon gamma (IFN-γ). Flow cytometry was used to detect the surface expressions of IFN-γR1 and IFN-γR2 as well as IL-12Rβ1and IL-12Rβ2 on monocytes and T lymphocytes, respectively.The phosphorylation of signal transducer and activator of transcription 1(STAT1) on monocytes and STAT4 on T lymphocytes were also detected by flow cytometry. Sanger sequencing was used to identify mutations in the IL-12Rβ1, STAT1, NEMO, and CYBB genes. ResultsP1's PBMCs exhibited reduced IFN-γ production, while P2's and P3's PBMCs exhibited impaired IL-12 induction. Low IL-12Rβ1 surface expression and reduced STAT4 phosphorylation were demonstrated by P1's T lymphocytes, while impaired STAT1 phosphorylation was detected in P2's monocytes. The impaired IκB-α degradation and abolished H2O2 production in monocytes and neutrophils of P3 and P4 were observed, respectively. Sanger sequencing revealed novel nonsense homozygous mutation: c.191 G>A/p.W64 * in exon 3 of the IL-12Rβ1 gene in P1, novel missense homozygous mutation: c.107 A>T/p.Q36L in exon 3 of the STAT1 gene in P2, missense hemizygous mutation:: c.950 A>C/p.Q317P in exon 8 of the NEMO gene in P3, and nonsense hemizygous mutation: c.868 C>T/p.R290X in exon 8 of CYBB gene in P4. ConclusionOur findings broaden the clinical and genetic spectra associated with IL-12/23/ISG15-IFN-γ axis anomalies. Additionally, our data suggest that TB patients in Pakistan should be investigated for potential genetic defects due to high prevalence of parental consanguinity and increased incidence of TB in the country.

Signal transducer and activator of transcription 3 and cancer associated fibroblasts jointly generate chemo-resistance and affect prognosis in epithelial ovarian cancer

Objective: To investigate the mechanism of signal transducer and activator of transcription 3 (STAT3) and cancer associated fibroblasts (CAF) jointly generate chemo-resistance in epithelial-ovarian cancer and their effect on prognosis. Methods: A total of 119 patients with high-grade ovarian serous cancer who received surgery in Cancer Hospital of Chinese Academy of Medical Sciences from September 2009 to October 2017 were collected. The clinico-pathological data and follow-up data were complete. Multivariate Cox regression model was used to analyze the prognostic factors. Ovarian cancer tissue chips of patients in our hospital were prepared. EnVision two-step method immunohistochemistry was used to detect the protein expression levels of STAT3, the specific markers of CAF activation, fibroblast activating protein (FAP), and type Ⅰ collagen (COL1A1) secreted by CAF. The relationship between the expression of STAT3, FAP, COL1A1 protein and drug resistance and prognosis of ovarian cancer patients was analyzed, and the correlation between the expression of three proteins was analyzed. These results were verified through the gene expression and prognostic information of human ovarian cancer tissues collected in the GSE26712 dataset of gene expression omnibus (GEO) database. Results: (1) Multivariate Cox regression model analysis showed that chemotherapy resistance was an independent risk factor for overall survival (OS) of ovarian cancer (P<0.001). (2) The expression levels of STAT3, FAP, and COL1A1 proteins in chemotherapy resistant patients were significantly higher than those in chemotherapy sensitive patients (all P<0.05). Patients with high expression of STAT3, FAP, and COL1A1 had significantly shorter OS than those with low expression (all P<0.05). According to the human ovarian cancer GSE26712 dataset of GEO database, patients with high expression of STAT3, FAP, and COL1A1 also showed shorter OS than patients with low expression (all P<0.05), the verification results were consistent with the detection results of ovarian cancer patients in our hospital. (3) Correlation analysis showed that the protein level of STAT3 was positively correlated with FAP and COL1A1 in our hospital's ovarian cancer tissue chips (r=0.47, P<0.001; r=0.30, P=0.006), the analysis of GEO database GSE26712 dataset showed that the expression of STAT3 gene and FAP, COL1A1 gene were also significantly positively correlated (r=0.31, P<0.001; r=0.52, P<0.001). Conclusion: STAT3 and CAF could promote chemotherapy resistance of ovarian cancer and lead to poor prognosis.

Chronic mucocutaneous candidiasis and immune dysregulation due to STAT1 Gain of Function

BackgroundGermline gain-of-function (GOF) mutations in the Signal Transducer and Activator of Transcription 1 (STAT1) gene have been associated with autosomal dominant chronic mucocutaneous candidiasis (CMCC), autoimmune and inflammatory manifestations. Although most patients with STAT1 GOF have CMCC, the disease has a broad phenotypic spectrum.Case Description: A 13-year-old male born to non-consanguineous parents with a past medical history of chronic mucocutaneous candidiasis, autoimmune hypothyroidism, and recurrent viral respiratory tract infections presented for immune evaluation. His medical history was also significant for chronic fatigue refractory to thyroid replacement therapy, chronic paronychia, oral thrush, pneumonia requiring hospitalization, recurrent chalazia status post excision, and prolonged tonsillitis. Laboratory results showed high total serum IgG levels with elevated IgG1 and IgG3 subclasses, elevated B cell counts with atypical lymphocytes, and chronic EBV-viremia. He had no clinical or laboratory evidence of active lymphoproliferative disease. He had normal lymphocyte proliferation to mitogens with impaired response to antigens. He had an adequate humoral response to protein and polysaccharide antigens. Targeted genetic testing for inborn errors of immunity showed a heterozygous variant in the STAT1 gene (c.1169T>C, p.MET390Thr), which had been previously reported in patients with STAT1 GOF. The patient was treated with oral fluconazole with interval improvement in CMCC and subsequently maintained on prophylactic fluconazole and TMP/SMX. He had an unremarkable family history, which suggests a de novo mutation in STAT1. ConclusionThe presence of CMCC and autoimmunity should raise concern for STAT1 GOF. Genetic testing for inborn errors of immunity can be a valuable tool in the diagnosis of patients with CMCC and can help guide therapy. Unfortunately, hematopoietic stem cell transplant has been associated with a high mortality rate in patients with STAT1 GOF. JAK inhibition therapy was recommended for this patient. However, there is currently no consensus regarding JAK inhibitor selection, dosing, treatment duration or biomarkers in STAT1 GOF.