Expression Of Signal Transducer And Activator Of Transcription 1 Research Articles

LINC01686 affects LPS-induced cytokine expression via the miR-18a-5p/A20/STAT1 axis in THP-1 cells.

Long noncoding RNAs (lncRNAs) are crucial in regulating various physiological and pathological processes, including immune responses. LINC01686 is a lncRNA with previously uncharacterized functions in immune regulation. This study aims to investigate the function of LINC01686 in lipopolysaccharide (LPS)-induced inflammatory responses in the human monocytic leukemia cell line THP-1 and its potential regulatory mechanisms involving miR-18a-5p and the anti-inflammatory protein A20. THP-1 cells were stimulated with LPS to induce inflammatory responses, followed by analysis of LINC01686 expression levels. The role of LINC01686 in regulating the expression of interleukin (IL)-6, IL-8, A20, and signal transducer and activator of transcription 1 (STAT1) was examined using small interfering RNA-mediated knockdown. Additionally, the involvement of miR-18a-5p in LINC01686-mediated regulatory pathways was assessed by transfection with decoy RNAs mimicking the miR-18a-5p binding sites of LINC01686 or A20 messenger RNA. LINC01686 expression was upregulated in THP-1 cells following LPS stimulation. Suppression of LINC01686 enhanced LPS-induced expression of IL-6 and IL-8, mediated through increased production of reactive oxygen species. Moreover, LINC01686 knockdown upregulated the expression and activation of IκB-ζ, STAT1, and downregulated A20 expression. Transfection with decoy RNAs reversed the effects of LINC01686 suppression on A20, STAT1, IL-6, and IL-8 expression, highlighting the role of LINC01686 in sponging miR-18a-5p and regulating A20 expression. This study provides the first evidence that LINC01686 plays a critical role in modulating LPS-induced inflammatory responses in THP-1 cells by sponging miR-18a-5p, thereby regulating the expression and activation of A20 and STAT1. These findings shed light on the complex regulatory mechanisms involving lncRNAs in immune responses and offer potential therapeutic targets for inflammatory diseases.

Genistein and Sex Hormone Supplementation Modulated Hepatic PPARα, δ, and γ Subtypes and STAT1 Expressions in a NASH Rat Model with Bilateral Orchidectomy.

Nonalcoholic steatohepatitis (NASH) is a progressive form of nonalcoholic fatty liver disease (NAFLD) that is characterized by hepatic inflammation and steatosis. Currently, limited data exist regarding the risk of NASH in transgender women and the treatment options for this particular population. The use of testosterone supplementation is unfavorable for transgender women, and estrogen supplementation is linked to an increased risk of breast cancer; thus, an isoflavone derivative compound known as "genistein" could serve as a viable substitute for a hormone supplement in this context. The purpose of this study was to investigate the treatment effects and mechanisms of actions of genistein and sex hormones in orchidectomized (ORX) rats with nonalcoholic steatohepatitis induced via a high-fat high-fructose diet (HFHF) model. Male Sprague-Dawley rats (n = 42) were randomly assigned into seven groups; control, ORX + standard diet, HFHF, ORX + HFHF, ORX + HFHF diet + testosterone (50 mg/kg body weight (BW) once weekly), ORX + HFHF diet + estradiol (1.6 mg/kg BW daily), and ORX + HFHF diet + genistein (16 mg/kg BW daily). The duration of the study was 6 weeks. Some parts of liver tissue were used for histological examination by H&E staining. The determination of fat accumulation was performed using Oil Red O staining. SREBP1c and FAS gene expression were quantified using real-time PCR technique. The levels of all types of peroxisome proliferator-activated receptors (PPARs; α, δ, γ), proteins, and signal transducer and activator of transcription 1 (STAT1) signaling pathway were determined by both immunoblotting and immunohistochemistry. Rats in the ORX + HFHF group had the highest degree of hepatic steatosis, lobular inflammation, and hepatocyte ballooning, and showed higher levels of genes related to de novo lipogenesis, including SREBP1c and FAS. The expression of PPARγ and STAT1 were upregulated, while the expression of PPARα and PPARδ were downregulated in the ORX + HFHF group. Testosterone, estradiol and genistein treatments improved NASH histopathology together with the reversal of all types of PPAR protein expressions. Interestingly, genistein decreased the levels of STAT1 protein expression more than those of testosterone and estradiol treatment. Genistein and sex hormone treatment could ameliorate NASH through the upregulation of PPARα, and PPARδ, and the suppression of PPARγ and STAT1 expression.

ENO2 promotes anoikis resistance in anaplastic thyroid cancer by maintaining redox homeostasis.

Anoikis presents a significant barrier in the metastasis of cancer. As the most aggressive type of thyroid cancer, anaplastic thyroid cancer (ATC) exhibits a high risk of metastasis and is characterized by high mortality. Therefore, investigating the molecular mechanisms of anoikis resistance in ATC is important for devising therapeutic targets in clinical research. Differentially Expressed Genes were screened in ATC cells under attached and detached culture conditions with RNA-seq. Investigate the impact of enolase 2 (ENO2) on apoptosis and spheroid formation by gain and loss of function. Changes of reactive oxygen species (ROS), glutathione (GSH) and nicotinamide adenine dinucleotide phosphate (NADPH) were detected to assess redox balance. The transcriptional regulatory role of signal transducer and activator of transcription 1 (STAT1) on ENO2 was validated through Dual-Luciferase Reporter Gene Assay. Explore the impact of ENO2 expression on the formation of lung metastases in nude mice. We found that the glycolysis process was activated in detached ATC cells. Several genes in the glycolysis process, particularly ENO2, a member of the enolase superfamily was upregulated in ATC cells cultured in suspension. The upregulation of ENO2 enabled the maintenance of redox balance by supplying GSH and NADPH, thereby preventing cells from undergoing anoikis. In terms of mechanism, the expression of STAT1 was enhanced in anoikis resistance cells, which in turn positively regulated the expression of ENO2. In vivo, ENO2-suppressed ATC cells resulted in a significantly lower rate of lung colonization compared to control ATC cells. Stable expression of ENO2 and the maintenance of redox balance played a pivotal role in facilitating anoikis resistance of ATC.

STAT1 negatively regulates human glioma U251 cell proliferation Huang et al: Role of STAT1 in glioma

Background Glioma is one of the most malignant tumors, which leads to high mortality in cancer patients. At present, there is no effective therapy for glioma. Therefore, it is urgent and necessary to find new molecular targets for anti-glioma therapy. Objective The present study aimed to investigate the role of signal transducer and activator of transcription 1 (STAT1) in the development and progression of human glioma and related mechanisms. Methods According to the instructions of Lipofectamine TM2000 transfection reagent, we transiently transfected the plasmid pcDNA3.1-STAT1 into glioma U251 cells. Then STAT1 expression in glioma U251 and LN382 cells was detected by Western blot. MTT was performed to assay the proliferative activity of U251 cells after STAT1 transduction, flow cytometry was used to detect cell cycle and apoptosis indicators, cell migration indicator was determined by Wound healing, and Western blot was used for detecting the expression level and change trend of p53, p21, bcl-2, Caspase-8, Cyclin A and Cyclin E in transfected cells. Results Overexpressed STAT1 significantly inhibited U251 cell proliferation and promoted U251 cell apoptosis. Meanwhile, high expression of STAT1 can increase the expression of p53, p21, and Caspase-8 while inhibiting the expression of bcl-2, Cyclin A, and Cyclin E. Conclusion Highly expressed STAT1 inhibits the proliferative activity of human glioma U251 cells and can promote tumor cell apoptosis and block cell cycle progression while regulating the expression of various signal transduction molecules. Thus, STAT1 has a critical function in the development and progression of glioma and is a novel target for glioma therapy.

Macrophage-Derived Factors with the Potential to Contribute to Pathogenicity of HIV-1 and HIV-2: Role of CCL-2/MCP-1.

Human immunodeficiency virus type 2 (HIV-2) is known to be less pathogenic than HIV-1. However, the mechanism(s) underlying the decreased HIV-2 pathogenicity is not fully understood. Herein, we report that β-chemokine CCL2 expression was increased in HIV-1-infected human monocyte-derived macrophages (MDM) but decreased in HIV-2-infected MDM when compared to uninfected MDM. Inhibition of CCL2 expression following HIV-2 infection occurred at both protein and mRNA levels. By microarray analysis, quantitative PCR, and Western blotting, we identified that Signal Transducer and Activator of Transcription 1 (STAT1), a critical transcription factor for inducing CCL2 gene expression, was also reduced in HIV-2-infected MDM. Blockade of STAT1 in HIV-infected MDM using a STAT1 inhibitor significantly reduced the production of CCL2. In contrast, transduction of STAT1-expressing pseudo-retrovirus restored CCL2 production in HIV-2-infected MDM. These findings support the concept that CCL2 inhibition in HIV-2-infected MDM is meditated by reduction of STAT1. Furthermore, we showed that STAT1 reduction in HIV-2-infected MDM was regulated by the CUL2/RBX1 ubiquitin E3 ligase complex-dependent proteasome pathway. Knockdown of CUL2 or RBX1 restored the expression of STAT1 and CCL2 in HIV-2-infected MDM. Taken together, our findings suggest that differential regulation of the STAT1-CCL2 axis may be one of the mechanisms underlying the different pathogenicity observed for HIV-1 and HIV-2.

The anti-inflammatory effect of ferulic acid is via the modulation of NFκB-TNF-α-IL-6 and STAT1-PIAS1 signaling pathways in 2-methoxyethanol-induced testicular inflammation in rats

BackgroundFerulic acid (FAC) is a component of plant cell walls, where it serves as a building block of lignin and pectin. As such, it is abundantly found in vegetables and other plants. In contrast, 2-methoxyethanol (2METH) is a testicular toxin commonly found in products used by humans. This study is aimed to investigate the effect of FAC on 2METH-induced testicular inflammation in rats. MethodFour groups of 5 animals each were used: Group I served as the control, Group II was exposed to 2METH only (100 mg/kg), Group III was administered 2METH (100 mg/kg) plus FAC (50 mg/kg), and Group IV served as the FAC (50 mg/kg) only group. All administrations were done orally for 30 days. ResultsAt the end of the study, rats administered 2METH only showed a significant increase in the testicular levels of interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α), inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX-2), and nuclear factor κB (NF-κB), as well as RNA gene expressions of Janus kinase 1 (JAK1), signal transducer and activator of transcription 1 (STAT1), and suppressor of cytokine signaling 1 (SOCS1) compared to the control group. In contrast, treatment with FAC led to a significant decrease in the testicular levels of IL-6, TNF-α, iNOS, COX-2, NF-κB, and gene expression of STAT1, while significantly increasing the testicular gene expression of protein inhibitor of activated STAT 1 (PIAS1) compared to rats exposed to 2METH only. ConclusionBased on the data gathered from this study, FAC demonstrated an anti-inflammatory effect by inhibiting the testicular activation of NF-κB through the downregulation of pro-inflammatory markers (IL-6, TNF-α, iNOS, and COX-2) and the inhibition of the STAT1-PIAS1 signaling pathway in rats.

Long non-coding RNA TLR8-AS1 induces preeclampsia through increasing TLR8/STAT1 axis.

Our current study tried to assay the role of long noncoding RNAs (lncRNAs) TLR8-AS1 in regulating preeclampsia. TLR8-AS1 expression was examined in the clinical placental tissues of preeclampsia patients and the trophoblast cells induced by lipopolysaccharide (LPS). Then, different lentivirus was infected into trophoblast cells to study the role of TLR8-AS1 in cell functions. Furthermore, interactions among TLR8-AS1, signal transducer and activator of transcription 1 (STAT1) and toll-like receptor 8 (TLR8) were determined. A rat model of preeclampsia induced by N(omega)-nitro-L-arginine methyl ester was developed to validate the in-vitro findings. High expression of TLR8-AS1 was detected in placental tissues of preeclampsia patients and LPS-induced trophoblast cells. In addition, overexpression of TLR8-AS1 arrested the proliferation, migration and invasion of trophoblast cells, which was related to the upregulation of TLR8 expression. Mechanistically, TLR8-AS1 recruited STAT1 to bind to the TLR8 promoter region, and thus promoted the transcription of TLR8. Meanwhile, overexpression of TLR8-AS1 was shown to aggravate preeclampsia by elevating TLR8 in vivo . Our study confirmed that TLR8-AS1 aggravated the progression of preeclampsia through increasing the expression of STAT1 and TLR8.

Gouqizi () seed oil reduces D-galactose induced inflammation in testis of rats Janus kinase 1/signal transducerand activator of transcription 1/nuclear factor-κB and.

To investigate the efficacy of Gouqizi () seed oil (FLSO) on D-gal induced inflammation in testis of rats and . In aging Sertoli cells (TM4 cells) induced by D-galactose (D-gal), the expression of upregulated aging-related proteins. The number of cells counted by cell counting kit (CCK)-8 assay showed a high number of cells disposed with FLSO at 50, 100 and 150 μg/mL compared to that for the aging model. , male Sprague-Dawley rats ( = 50, 8-week-old, 230-255 g) were randomly categorized into control, aging model, and FLSO (low-, medium-, and high-dose) groups. The expression of nuclear factor-κB (NF-κB) and its upstream factors [Janus kinase 1 (JAK1) and signal transducerand activator of transcription 1 (STAT1)] was detected by Western blot and immunofluorescence, related inflammatory factors quantified by enzyme-linked immunosorbent assay. Evaluation of testicular tissue by Johnsen score, the spermatogenic function was explored. The expression of interleukin-1β (IL-1β) ( < 0.05), IL-6 ( < 0.001), and tumor necrosis factor α (TNF-α) ( < 0.05) was decreased significantly, while that of heme oxygenase-1 (HO-1) ( < 0.001) and IL-10 ( < 0.05) was increased in cells disposed with FLSO 100 μg/mL. FLSO inhibited the expression of NF-B and declined p-p65/p65 ( < 0.01), as detected by Western blotting. In, the levels in serum of IL-1β ( < 0.001), IL-6 ( < 0.05), and TNF-( < 0.01) declined while IL-10 ( < 0.05) was upregulated post-FLSO treatment. In addition, the expression of JAK-1 and STAT1 increased significantly in testicular tissue of rats treated with FLSO as compared to the aging model of rats ( < 0.001), while the expression of NF-κB ( < 0.001) declined in the testis in the FLSO group, as assessed by immunofluorescence. The levels of inhibor B and testosterone in serum both increased (< 0.05). In conclusion, this study determined the protective effects of FLSO to tolerate inflammatory injury in the testis, indicating that FLSO alleviates inflammation JAK-1/STAT1/NF-κB pathway.

Downregulated miR-129-5p expression inhibits rat pulmonary fibrosis by upregulating STAT1 gene expression in macrophages

ObjectiveThis study investigated the mechanism by which microRNA-129-5p (miR-129-5p) in macrophages affects pulmonary fibrosis in rats by regulating the expression of the signal transducer and activator of transcription 1 (STAT1) gene. MethodsAfter the establishment of a pulmonary fibrosis rat model, quantitative real-time polymerase chain reaction (qRT-PCR) was employed to detect the expression of miR-129-5p in the sham group and model group. The binding sites between miR-129-5p and STAT1 were predicted online and verified by using a dual luciferase reporter system. qRT-PCR and Western blot analyses were used to test the effect of miR-129-5p on STAT1 gene expression. M2 macrophages were isolated and induced, and exosomes were extracted. Cell proliferation was detected by EdU. Furthermore, qRT-PCR was performed to detect the expression of STAT1, collagen type I A2 (COL1A2), collagen type III A1 (COL3A1), fibronectin, and α-SMA in cells and tissues followed by the detection of CD9, CD63, CD81, CD31 and STAT1 protein expression using a Western blot analysis. The pulmonary fibrosis area was detected by Masson staining followed by the immunohistochemical detection of α-smooth muscle actin (α-SMA) and type I collagen (COL-I) expression in pulmonary fibroblasts. ResultsCompared with the sham group, the expression level of miR-129-5p in the model group was significantly increased (P < 0.05). miR-129-5p was observed to negatively regulate the expression of STAT1 (P < 0.05). The in vitro cell transfection experiments showed that after inhibiting the expression of miR-129-5p, the expression of STAT1 was increased, and the proliferation of fibroblasts and pulmonary fibrosis were inhibited (all P < 0.05). Furthermore, compared with the fibroblasts without coculture, the proliferation of the fibroblasts cocultured with M2 macrophage-secreted exosomes was clearly increased, and the expression levels of COL1A2, COL3A1, fibronectin and α-SMA were significantly increased (all P < 0.05). Compared with the mimic NC-exo group, the miR-129-5p-exo group had significantly increased proliferation of fibroblasts, decreased expression of STAT1, and significantly increased expression of COL1A2, COL3A1, fibronectin and α-SMA, and M2 macrophage-secreted exosomes could carry miR-129-5p to fibroblasts. Furthermore, the in vivo experiment confirmed that the exosomes of M2 macrophages could carry miR-129-5p, which could regulate M2 macrophages with pulmonary fibrosis in vivo. ConclusionM2 macrophages can carry miR-129-5p to pulmonary interstitial fibroblasts and inhibit STAT1 gene expression, which may lead to the proliferation of fibroblasts and promote pulmonary fibrosis. The downregulation of miR-129-5p can significantly promote STAT1 gene expression in macrophages to inhibit pulmonary fibrosis in rats.

A chemical probe inhibitor targeting STAT1 restricts cancer stem cell traits and angiogenesis in colorectal cancer

BackgroundColorectal cancer (CRC) is a worldwide cancer with rising annual incidence. New medications for patients with CRC are still needed. Recently, fluorescent chemical probes have been developed for cancer imaging and therapy. Signal transducer and activator of transcription 1 (STAT1) has complex functions in tumorigenesis and its role in CRC still needs further investigation.MethodsRNA sequencing datasets in the NCBI GEO repository were analyzed to investigate the expression of STAT1 in patients with CRC. Xenograft mouse models, tail vein injection mouse models, and azoxymethane/dextran sodium sulfate (AOM/DSS) mouse models were generated to study the roles of STAT1 in CRC. A ligand-based high-throughput virtual screening approach combined with SWEETLEAD chemical database analysis was used to discover new STAT1 inhibitors. A newly designed and synthesized fluorescently labeled 4’,5,7-trihydroxyisoflavone (THIF) probe (BODIPY-THIF) elucidated the mechanistic actions of STAT1 and THIF in vitro and in vivo. Colonosphere formation assay and chick chorioallantoic membrane assay were used to evaluate stemness and angiogenesis, respectively.ResultsUpregulation of STAT1 was observed in patients with CRC and in mouse models of AOM/DSS-induced CRC and metastatic CRC. Knockout of STAT1 in CRC cells reduced tumor growth in vivo. We then combined a high-throughput virtual screening approach and analysis of the SWEETLEAD chemical database and found that THIF, a flavonoid abundant in soybeans, was a novel STAT1 inhibitor. THIF inhibited STAT1 phosphorylation and might bind to the STAT1 SH2 domain, leading to blockade of STAT1-STAT1 dimerization. The results of in vitro and in vivo binding studies of THIF and STAT1 were validated. The pharmacological treatment with BODIPY-THIF or ablation of STAT1 via a CRISPR/Cas9-based strategy abolished stemness and angiogenesis in CRC. Oral administration of BODIPY-THIF attenuated colitis symptoms and tumor growth in the mouse model of AOM/DSS-induced CRC.ConclusionsThis study demonstrates that STAT1 plays an oncogenic role in CRC. BODIPY-THIF is a new chemical probe inhibitor of STAT1 that reduces stemness and angiogenesis in CRC. BODIPY-THIF can be a potential tool for CRC therapy as well as cancer cell imaging.

STAT1/SOCS1/3 Are Involved in the Inflammation-Regulating Effect of GAS6/AXL in Periodontal Ligament Cells Induced by Porphyromonas gingivalis Lipopolysaccharide In Vitro.

Periodontitis involves chronic inflammation of the tissues around the teeth caused by plaque and the corresponding immune response. Growth arrest-specific protein 6 (GAS6) and AXL receptor tyrosine kinase (AXL) are known to be involved in inflammatory diseases, while signal transducer and activator of transcription-1 (STAT1) and suppressor of cytokine signaling (SOCS) are related to inflammatory processes. Moreover, miRNA34a directly targets AXL to regulate the AXL expression. However, the specific roles of GAS6 and AXL in periodontitis remain unclear. This study was designed to explore the effect and mechanism of AXL on the expression of inflammatory cytokines induced by Porphyromonas gingivalis lipopolysaccharide (P. gingivalis LPS) in human periodontal ligament cells (hPDLCs). The effects of different concentrations of P. gingivalis LPS on the expression of GAS6/AXL in hPDLCs were observed. Additionally, the effect of LPS on AXL was investigated by transfection of the miRNA34a inhibitor. AXL was knocked down or overexpressed to observe the release of inflammatory cytokines interleukin- (IL-) 8 and IL-6. The results showed that the expression levels of GAS6 and AXL decreased after P. gingivalis LPS infection. Transfection of a miR-34a inhibitor to hPDLCs demonstrated a role of miR-34a in the downregulation of AXL expression induced by LPS. Moreover, AXL knockdown or overexpression influencing the expression of IL-8 and IL-6 was investigated under LPS stimulation. AXL knockdown decreased the expression of STAT1 and SOCS1/3. Overall, these results demonstrate that AXL inhibits the expression of LPS-induced inflammatory cytokines in hPDLCs and that STAT1 and SOCS1/3 are involved in the regulation of inflammation by GAS6/AXL.

Human Cytomegalovirus UL23 Attenuates Signal Transducer and Activator of Transcription 1 Phosphorylation and Type I Interferon Response.

Human cytomegalovirus (HCMV), the human beta-herpesvirus, can cause severe syndromes among both immunocompromised adult patients and newborns. Type I interferon (IFN-I) exerts an important effect to resist infections caused by viruses such as HCMV, while IFN evasion may serve as a key determining factor for viral dissemination and disease occurrence within hosts. In this study, UL23, a tegument protein of HCMV, was confirmed to be a key factor for negatively regulating the type I IFN immune response. A detailed analysis indicated that the viral UL23 protein increases the IFN-I antiviral resistance during HCMV infections. Furthermore, UL23 was shown to significantly reduce the levels of IFN-stimulated genes (ISGs) and promoter activity of IFN-I-stimulated response element. Mechanically, UL23 was discovered to impair the signal transducer and activator of transcription 1 (STAT1) phosphorylation, although it was not found to affect phosphorylation and expression of STAT2, Janus activated kinase 1, or tyrosine kinase 2, which are associated with IFN-I signal transduction pathway. Additionally, a significantly reduced nuclear expression of STAT1 but not of IFN regulatory factor 9 or STAT2 was observed. Findings of this study indicate that HCMV UL23 is a viral antagonist that acts against the cellular innate immunity and reveal a possible novel effect of UL23 on IFN-I signaling.

C16, a novel sinomenine derivatives, promoted macrophage reprogramming toward M2-like phenotype and protected mice from endotoxemia.

Macrophage plays a critical part in host defense, tissue repair, and anti-inflammation; Macrophage reprogramming is responsible for disease development or regression. We aimed to clarify the effect of sinomenine-4-hydroxy-palmitate (C16), on macrophage reprogramming and anti-inflammatory in endotoxemia model. According to a structure modification of SIN (Sinomenine), C16 was found. Then, based on the endotoxin model, the mice liver and kidney toxicity was evaluated and serum cytokines level of IL-6 (Interleukin-6), TNF-α (Tumor necrosis factor-α), and IL-1β (Interleukin-1β) were measured by ELISA (Enzyme linked immunosorbent assay). Then, we confirmed the effect of C16 on macrophages reprogramming, we used the flow cytometry to test the effect of C16 on macrophages apoptosis in vitro. Then, iNOS (Inducible nitric oxide synthase), M1-type related cytokines, such as IL-1β, TNF-α, and M2-type related cytokines, such as Arg-1 (Arginase-1), CD206, Fizz1, and Ym1 was detected, which expressed in ANA-1 and primary peritoneal macrophages. To further explore the molecular mechanism of C16 in reprogramming of macrophages from M1 toward M2 phenotype, the expression of STAT1 (signal transducer and activator of Transcription 1), STAT3, ERK1/2 (extracellular signal regulated kinase1/2), AKT, p38, and its corresponding phosphorylation were determined by western blot. Our results demonstrated that C16 improved the survival rate of LPS- (lipopolysaccharide) challenged mice and decreased the inflammatory cytokines expression; After C16 treatment, the expression of M1 phenotype correlation factors decreased significantly, while the expression of M2 phenotype correlation factors increased significantly at different levels compared with normal group. It indicated that C16 reprogram macrophages phenotype from M1 toward M2 following LPS stimulus. Furthermore, the results also showed that C16 showed anti-inflammatory effect by inhibiting LPS-induced p38, AKT and STAT1 phosphorylation and contributing ERK1/2 activation. C16 promoted macrophage reprogramming toward M2-like phenotype via p-p38/p-AKT or STAT1 signals pathway and C16 might be a valid candidate for inflammatory disease.

Simultaneous silencing Aurora-A and UHRF1 inhibits colorectal cancer cell growth through regulating expression of DNMT1 and STAT1.

Aurora-A has attracted a great deal of interest as a potential therapeutic target for patients with CRC. However, the outcomes of inhibitors targeting Aurora-A are not as favorable as expected, and the basis behind the ineffectiveness remains unknown. Here, we found that signal transducer and activator of transcription 1 (STAT1) was highly expressed in colorectal cancer (CRC) xenograft mouse models that were resistant to alisertib, an Aurora-A inhibitor. Unexpectedly, we found that alisertib disrupted Aurora-A binding with ubiquitin-like with plant homeodomain and ring finger domain 1 (UHRF1), leading to UHRF1 mediated ubiquitination and degradation of DNA methyltransferase 1 (DNMT1), which in turn resulted in demethylation of CpG islands of STAT1 promoter and STAT1 overexpression. Simultaneous silencing Aurora-A and UHRF1 prevented STAT1 overexpression and effectively inhibited CRC growth. Hence, concomitant targeting Aurora-A and UHRF1 can be a promising therapeutic strategy for CRC.

Expression of STAT1 is positively correlated with PD-L1 in human ovarian cancer

ABSTRACT Signal transducer and activator of transcription 1 (STAT1) is related to the immune microenvironment of tumorigenesis. The programmed cell death 1 (PD-1) and its ligand (PD-L1) have been reported to be important in immunotherapy by mediating tumor immune evasion. Blocking the PD-1/PD-L1 pathway can restore the endogenous anti-tumor immune response. This study aimed to examine the expression of STAT1, PD-1, and PD-L1 and the correlation between selected markers in human epithelial ovarian cancer (EOC). The results showed that malignant tumors contained more STAT1, PD-1, and PD-L1 positive cells. The expression of STAT1 and PD-L1 was associated with age, whereas PD-1 and PD-L1 associated with histopathological type, in patients with ovarian tumors. Moreover, the expression of STAT1 was found to be associated with disease stages and the grade of serous carcinoma. STAT1 expression was higher in OC cells than normal ovarian surface epithelial cells and was positively correlated with PD-L1 expression. The knockdown of STAT1 decreased PD-L1 expression, whereas overexpression of STAT1 increased PD-L1 expression. Furthermore, the expression of STAT1, PD-1, and PD-L1 was lower in paclitaxel-resistant cells than sensitive cells. Finally, STAT1 affected the overall survival and progression-free survival of patients with EOC. These findings suggest that STAT1, PD-1, and PD-L1 are the tissue markers of EOC and imply the possibility that the high level of STAT1, PD-1, and PD-L1 may favor the checkpoint immunotherapy in patients with EOC, but may have a limit in paclitaxel-resistant patients because of the low expression of STAT1, PD-1, and PD-L1 in paclitaxel-resistant cells.

Type II interferon signaling in the brain during a viral infection with age-dependent pathogenesis.

Viral infections of the central nervous system (CNS) often cause disease in an age-dependent manner, with greater neuropathology during the fetal and neonatal periods. Transgenic CD46+ mice model these age-dependent outcomes through a measles virus infection of CNS neurons. Adult CD46+ mice control viral spread and survive the infection in an interferon gamma (IFNγ)-dependent manner, whereas neonatal CD46+ mice succumb despite similar IFNγ expression in the brain. Thus, we hypothesized that IFNγ signaling in the adult brain may be more robust, potentially due to greater basal expression of IFNγ signaling proteins. To test this hypothesis, we evaluated the expression of canonical IFNγ signaling proteins in the neonatal and adult brain, including the IFNγ receptor, Janus kinase (JAK) 1/2, and signal transducer and activator of transcription-1 (STAT1) in the absence of infection. We also analyzed the expression and activation of STAT1 and IFNγ-stimulated genes during MV infection. We found that neonatal brains have equivalent or greater JAK/STAT1 expression in the hippocampus and the cerebellum than adults. IFNγ receptor expression varied by cell type in the brain but was widely expressed on neuronal and glial cells. During MV infection, increased STAT1 expression and activation correlated with viral load in the hippocampus regardless of age, but not in the cerebellum where viral load was consistently undetectable in adults. These results suggest the neonatal brain is capable of initiating IFNγ signaling during a viral infection, but that downstream STAT1 activation is insufficient to limit viral spread.

Highly expressed STAT1 contributes to the suppression of stemness properties in human paclitaxel-resistant ovarian cancer cells.

Signal transducer and activator of transcription-1 (STAT1) is an important factor in various cellular processes. The cancer stem cell (CSC) is considered as a tumor-initiating cell that drives the inner hierarchy in many cancers including epithelial ovarian cancer (EOC). Here, we explored for the first time the regulation of STAT1 on stemness properties in chemoresistant EOC cells. The paclitaxel (PTX)-resistant EOC cell line (OV3R-PTX) was derived from PTX-sensitive OVCAR-3 cells treated by the PTX regimen. A single cell clone OV3R-PTX-B4 was selected by fluorescence-activated cell sorting. PTX-resistant cells grew slowly in conventional 2D and 3D cultures, but tumor xenograft with PTX-resistant cells grew fast in nude mice. Interestingly, OV3R-PTX-B4 cells shared the characteristics of CSCs and stemness properties were found to be increased in the non-adherent spheroid culture system. The PTX-resistant cells had a high expression of CSC-related markers and low expression of STAT1 that had a high methylation level of CpG in its promoter region. Overexpressed STAT1 suppressed stemness properties, cell proliferation, and colony formation and favored the overall survival of patients with EOC. In summary, these data indicate a regulatory mechanism of STAT1 underlying drug resistance and provide a potential therapeutic application for EOC patients with PTX resistance.

Effects of MIF on proliferation, migration, and STAT1 pathway of colon cancer cells

Abstract Objective This study aimed to investigate how macrophage migration inhibitory factor (MIF) regulates the interaction of signal transducer and activator of transcription 1 (STAT1) with CD74, and affects colon cancer proliferation and invasion. Methods After transfecting MIF small interfering RNA into the SW480 cell line, the expression of STAT1 and CD74 mRNA was detected by qRT-PCR and western blotting. Transwell and MTT assays were performed to detect the colon cancer cell invasion and proliferation ability. Co-immunoprecipitation was used to detect the interaction between CD74 and STAT1 proteins in the treated and control groups. Results The cellular biological assays (MTT and Transwell) showed that the proliferation and invasion ability of colon cancer cells decreased after MIF knockdown; the results showed significant statistical difference (P &lt; 0.05). The results of the co-immunoprecipitation assay suggested that MIF knockdown in colon cancer cells could inhibit the binding of CD74 and STAT1 proteins; statistical difference was observed between the two groups (P &lt; 0.05). Conclusion MIF can increase the proliferation and invasion of colon cancer cells by promoting the combination of CD74 and STAT1.

Changes in expression of interferon-stimulated genes and ubiquitin activating enzyme E1-like in ovine thymus during early pregnancy

As the main signal for the maternal recognition in ruminants, interferon-tau (IFNT) stimulates expression of interferon-stimulated genes (ISGs) in uterus and many extrauterine tissues. However, it is unclear that early pregnancy induces expression of signal transducer and activator of transcription 1 (STAT1), myxovirusresistance 1 (Mx1), interferon-gamma-inducible protein 10 (IP-10) and ubiquitin activating enzyme E1-like protein (UBE1L) in maternal thymus. In this study, ovine thymuses were sampled on day 16 of the estrous cycle and on days 13, 16 and 25 of gestation, and the expression of STAT1, Mx1, IP-10 and UBE1L was detected by real-time quantitative PCR, Western blot and immunohistochemistry. The results revealed that the expression of STAT1 and IP-10 reached peaks on day 16 of pregnancy, and expression of Mx1 was enhanced on day 25 of pregnancy, and STAT1 protein was located in the epithelial reticular cells, capillaries and thymic corpuscles. However, expression of UBE1L was declined during early pregnancy. In conclusion, early pregnancy influences expression of STAT1, Mx1, IP-10 and UBE1L in maternal thymus, which may participate in regulation of maternal immune tolerance during early pregnancy in sheep.

In the peripheral blood mononuclear cells (PBMCs) of HCV infected patients the expression of STAT1 and IRF-1 is downregulated while that ofcaspase-3 upregulated.

Several peripheral blood mononuclear cell (PBMC) defects have been linked with hepatitis C virus (HCV) infection, including alterations in cytokine secretion and increased cell death. This study was performed to investigate the expression levels of signal transducer and activator of transcription 1 (STAT1), interferon regulatory factor 1 (IRF-1), and caspase 3 in PBMCs of patients infected with HCV. STAT1, IRF-1, and caspase 3 expression levels were compared in PBMCs from 19 untreated (naïve) HCV+ patients, 8 treated (sustained responder [SR]) HCV patients, and 20 HCV- healthy controls. Moreover, PBMCs from naïve HCV+ patients and SR-HCV patients were also evaluated for HCV RNA expression. The expression levels of STAT-1 and IRF-1 were significantly downregulated in PBMCs from naïve HCV+ patients (P Keywords: PBMC; hepatitis C virus; STAT1; IRF-1; caspase-3.