Cytokine Networks in the Pathophysiology of Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract. Cytokine-targeted therapies have transformed the treatment of IBD, providing control of symptoms and longer relapse-free periods. However, many patients fail to respond, highlighting the need for therapies tailored to the underlying cell and molecular disease drivers. Here we discuss the progression of IBD from the perspective of remodeling of cytokine networks. We place well-established and under-studied cytokine modules in the context of cellular interactions, their dynamic regulation in early and late stages of disease (i.e., fibrosis), and their current and potential use in the clinic. Examining how particular cytokine networks drive distinct features and phases of IBD will shed light on the etiology of IBD and provide a basis for more effective treatments.

The stress-response sensor chop regulates the function and accumulation of myeloid-derived suppressor cells in tumors.

Adaptation of malignant cells to the hostile milieu present in tumors is an important determinant of their survival and growth. However, the interaction between tumor-linked stress and antitumor immunity remains poorly characterized. Here, we show the critical role of the cellular stress sensor C/EBP-homologous protein (Chop) in the accumulation and immune inhibitory activity of tumor-infiltrating myeloid-derived suppressor cells (MDSCs). MDSCs lacking Chop had decreased immune-regulatory functions and showed the ability to prime T cell function and induce antitumor responses. Chop expression in MDSCs was induced by tumor-linked reactive oxygen and nitrogen species and regulated by the activating-transcription factor-4. Chop-deficient MDSCs displayed reduced signaling through CCAAT/enhancer-binding protein-ß, leading to a decreased production of interleukin-6 (IL-6) and low expression of phospho-STAT3. IL-6 overexpression restored immune-suppressive activity of Chop-deficient MDSCs. These findings suggest the role of Chop in tumor-induced tolerance and the therapeutic potential of targeting Chop in MDSCs for cancer immunotherapy.

STAT3 is over-activated within CD163pos bone marrow macrophages in both Multiple Myeloma and the benign pre-condition MGUS.

Tumour-associated macrophages (TAMs) support cancer cell survival and suppress anti-tumour immunity. Tumour infiltration by CD163pos TAMs is associated with poor outcome in several human malignancies, including multiple myeloma (MM). Signal transducer and activator of transcription 3 (STAT3) is over-activated in human cancers, and specifically within TAMs activation of STAT3 may induce an immunosuppressive (M2-like) phenotype. Therefore, STAT3-inhibition in TAMs may be a future therapeutic strategy.We investigated TAM markers CD163, CD206, and activated STAT3 (pSTAT3) in patients with MGUS (n = 32) and MM (n = 45), as well as healthy controls (HCs, n = 13).Blood levels of the macrophage biomarkers sCD163 and sCD206, and circulating cytokines, as well as bone marrow mRNA expression of CD163 and CD206, were generally increased in MGUS and MM patients, compared to HCs, but to highly similar levels. By immunohistochemistry, bone marrow levels of pSTAT3 were increased specifically within CD163pos cells in both MGUS and MM patients.In conclusion, macrophage-related inflammatory changes, including activation of STAT3, were present already at the MGUS stage, at similar levels as in MM. Specific increase in pSTAT3 levels within CD163pos cells supports that the CD163 scavenger receptor may be a useful target for future delivery of STAT3-inhibitory drugs to TAMs in MM patients.

Curcumol Attenuates Endometriosis by Inhibiting the JAK2/STAT3 Signaling Pathway.

BACKGROUND Curcumol is a hydrogenated austenitic compound with hemiketal. In this study we evaluated the effects of curcumol on local inflammatory response, cell proliferation, and metastasis in endometriosis, and elucidated the underlying mechanisms. MATERIAL AND METHODS Ectopic endometrial stromal cells were treated with increasing doses of curcumol. The MTT assay was used to assess cell viability. FITC-labeled annexin-V/PI double-staining method and flow cytometry were used to determine cell apoptosis. Cell migration was evaluated using a wound healing assay. ELISA kits were used to detect the levels of TNF-alpha, IL-6, and IL-1ß. Western blot assay was used to examine the phosphorylation degree of JAK2 and STAT3 and the expression of Bax, Bcl2, and caspase-3 proteins. Autologous endometrial transplantation was used to establish a rat model to assess the anti-EMS effect of curcumol in vivo. RESULTS Curcumol can inhibit the proliferation of ectopic endometrial stromal cells, promote cell apoptosis, and weaken cell migration ability. Curcumol can reduce the expression of Bax and caspase-3 protein and increase the expression of Bcl2 protein. Curcumol also can inhibit the secretion of inflammatory cytokines, including tumor necrosis cytokines (TNF)-alpha, interleukin (IL)-6, and IL-1ß, by ectopic endometrial stromal cells. In addition, curcumol can also inhibit the phosphorylation of JAK2 and STAT3. In vivo experiments also proved that curcumol could inhibit the growth of ectopic lesions in EMS model rats. CONCLUSIONS Curcumol can inhibit the JAK2/STAT3 pathway, reduce the inflammatory cytokines secreted by ectopic endometrial stromal cells, inhibit cell proliferation and migration, and reduce the volume of ectopic lesions.

HuR counteracts miR-330 to promote STAT3 translation during inflammation-induced muscle wasting.

Debilitating cancer-induced muscle wasting, a syndrome known as cachexia, is lethal. Here we report a posttranscriptional pathway involving the RNA-binding protein HuR as a key player in the onset of this syndrome. Under these conditions, HuR switches its function from a promoter of muscle fiber formation to become an inducer of muscle loss. HuR binds to the STAT3 (signal transducer and activator of transcription 3) mRNA, which encodes one of the main effectors of this condition, promoting its expression both in vitro and in vivo. While HuR does not affect the stability and the cellular movement of this transcript, HuR promotes the translation of the STAT3 mRNA by preventing miR-330 (microRNA 330)-mediated translation inhibition. To achieve this effect, HuR directly binds to a U-rich element in the STAT3 mRNA-3'untranslated region (UTR) located within the vicinity of the miR-330 seed element. Even though the binding sites of HuR and miR-330 do not overlap, the recruitment of either one of them to the STAT3-3'UTR negatively impacts the binding and the function of the other factor. Therefore, together, our data establish the competitive interplay between HuR and miR-330 as a mechanism via which muscle fibers modulate, in part, STAT3 expression to determine their fate in response to promoters of muscle wasting.

Myostatin deficiency not only prevents muscle wasting but also improves survival in septic mice.

Sepsis remains a leading cause of mortality in critically ill patients. Muscle wasting is a major complication of sepsis and negatively affects clinical outcomes. Despite intense investigation for many years, the molecular mechanisms underlying sepsis-related muscle wasting are not fully understood. In addition, a potential role of muscle wasting in disease development of sepsis has not been studied. Myostatin is a myokine that downregulates skeletal muscle mass. We studied the effects of myostatin deficiency on muscle wasting and other clinically relevant outcomes, including mortality and bacterial clearance, in mice. Myostatin deficiency prevented muscle atrophy along with inhibition of increases in muscle-specific RING finger protein 1 (MuRF-1) and atrogin-1 expression and phosphorylation of signal transducer and activator of transcription protein 3 (STAT3; major players of muscle wasting) in septic mice. Moreover, myostatin deficiency improved survival and bacterial clearance of septic mice. Sepsis-induced liver dysfunction, acute kidney injury, and neutrophil infiltration into the liver and kidney were consistently mitigated by myostatin deficiency, as indicated by plasma concentrations of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and neutrophil gelatinase-associated lipocalin (NGAL) and myeloperoxidase activity in the organs. Myostatin deficiency also inhibited sepsis-induced increases in plasma high-mobility group protein B1 (HMGB1) and macrophage inhibitory cytokine (MIC)-1/growth differentiation factor (GDF)-15 concentrations. These results indicate that myostatin plays an important role not only in muscle wasting but also in other clinically relevant outcomes in septic mice. Furthermore, our data raise the possibility that muscle wasting may not be simply a complication, but myostatin-mediated muscle cachexia and related changes in muscle may actually drive the development of sepsis as well.NEW & NOTEWORTHY Muscle wasting is a major complication of sepsis, but its role in the disease development is not known. Myostatin deficiency improved bacterial clearance and survival and mitigated damage in the liver and kidney in septic mice, which paralleled prevention of muscle wasting. These results raise the possibility that muscle wasting may not simply be a complication of sepsis, but myostatin-mediated cachexic changes may have a role in impaired bacterial clearance and mortality in septic mice.

Red nucleus IL-33 facilitates the early development of mononeuropathic pain in male rats by inducing TNF-α through activating ERK, p38 MAPK, and JAK2/STAT3.

BACKGROUND: Our recent studies have identified that the red nucleus (RN) dual-directionally modulates the development and maintenance of mononeuropathic pain through secreting proinflammatory and anti-inflammatory cytokines. Here, we further explored the action of red nucleus IL-33 in the early development of mononeuropathic pain. METHODS: In this study, male rats with spared nerve injury (SNI) were used as mononeuropathic pain model. Immunohistochemistry, Western blotting, and behavioral testing were used to assess the expressions, cellular distributions, and actions of red nucleus IL-33 and its related downstream signaling molecules. RESULTS: IL-33 and its receptor ST2 were constitutively expressed in the RN in naive rats. After SNI, both IL-33 and ST2 were upregulated significantly at 3 days and peaked at 1 week post-injury, especially in RN neurons, oligodendrocytes, and microglia. Blockade of red nucleus IL-33 with anti-IL-33 neutralizing antibody attenuated SNI-induced mononeuropathic pain, while intrarubral administration of exogenous IL-33 evoked mechanical hypersensitivity in naive rats. Red nucleus IL-33 generated an algesic effect in the early development of SNI-induced mononeuropathic pain through activating NF-κB, ERK, p38 MAPK, and JAK2/STAT3, suppression of NF-κB, ERK, p38 MAPK, and JAK2/STAT3 with corresponding inhibitors markedly attenuated SNI-induced mononeuropathic pain or IL-33-evoked mechanical hypersensitivity in naive rats. Red nucleus IL-33 contributed to SNI-induced mononeuropathic pain by stimulating TNF-α expression, which could be abolished by administration of inhibitors against ERK, p38 MAPK, and JAK2/STAT3, but not NF-κB. CONCLUSIONS: These results suggest that red nucleus IL-33 facilitates the early development of mononeuropathic pain through activating NF-κB, ERK, p38 MAPK, and JAK2/STAT3. IL-33 mediates algesic effect partly by inducing TNF-α through activating ERK, p38 MAPK and JAK2/STAT3.

STAT3 Contributes to Intracranial Aneurysm Formation and Rupture by Modulating Inflammatory Response.

Intracranial aneurysm (IA) is a common type of refractory cerebrovascular diseases. Inflammatory responses have been reported to be associated with the pathogenesis of IA. We aimed to study the role of STAT3 on IA formation and inflammatory response. STAT3 expression and clinicopathological factors were analyzed in IA and normal cerebral arteries. mRNA level of STAT3 was detected in normal, unruptured, and ruptured IA tissues by RT-PCR and Western blot. Inflammatory cytokines were examined by ELISA in unruptured, ruptured IA tissues, as well as cells with STAT3 overexpression or knockdown. mRNA of phenotypic modulation-related factors was tested by RT-PCR in STAT3 overexpressing or knockdown VSMCs. STAT3 expression was upregulated in ruptured IA tissues and highly associated with IA diameter and IA type. Inflammatory cytokine secretion was increased in ruptured IA samples and positively correlated with STAT3 expression. STAT3 overexpression led to enhanced expression of SM-α actin, SM-MHC, MMP2, and MMP9, and increased secretion of inflammatory cytokines. Our findings have demonstrated that STAT3 is a key regulator in IA formation by modulating inflammatory cytokine expression.

Inhibition of miR-144/199 promote myeloma pathogenesis via upregulation of versican and FAK/STAT3 signaling.

The continuous rise in relapse rate and mortality for multiple myeloma (MM) demands an effective treatment option. The microRNAs are emerging nowadays for their promising therapeutic potential. Earlier, we reported involvement of Versican (VCAN) in myeloma pathogenesis which could be inhibited by miR-144 and miR-199 in stroma. However, there is dearth of literature showcasing the direct effect of these miRs in association with VCAN in MM. Expression of miR-144 and miR-199 was determined in myeloma cell lines (RPMI8226 & U266). These miRs were inhibited by small oligos to elucidate changes in expression of VCAN along with variation in parameters such as proliferation, apoptosis, migration and invasion in vitro. Moreover, effect on certain downstream signaling cascades was also evaluated. Lastly, interaction of miRs with VCAN was assessed by reporter luciferase assay. microRNAs expression were found significantly elevated in myeloma cells in comparison to stromal levels reported previously. The antagomirs-mediated inhibition of miR-144 and miR-199 significantly induced VCAN expression in myeloma cells along with alteration in myeloma-associated parameters in favor of myeloma pathogenesis with downstream activation of FAK/STAT3 signaling. Interestingly, miR-144 found to have direct binding with VCAN 3' UTR while miR-199 possess different mechanism. The inhibition of miR-144 and miR-199 contributed in myeloma progression via upregulation of VCAN in vitro affirming the translational significance of VCAN and associated microRNAs in MM. These miRs, hence might be employed for targeting VCAN and might emerge as an effective therapy for the better outcome of MM in clinical settings in future.

IL-6/STAT3-mediated autophagy participates in the development of age-related glomerulosclerosis.

The standard of age-related glomerulosclerosis is unclear. Both signal transducer and activator of transcription 3 (STAT3) and autophagy are involved in age-related kidney disease. Therefore, we aimed to explore the standard, as well as the potential mechanism(s). A total of 44 patients who underwent radical nephrectomy were enrolled. Pearson analysis was performed to investigate the parameters with ages. The patients were divided into the young- and aged-kidney groups. Kidney morphological changes were evaluated by histology staining, senescence was evaluated by senescence-associated-ß-galactosidase (SA-ß-gal) staining, and autophagosome was measured by transmission electron microscopy. Moreover, Western blot and/or immunohistochemistry were accomplished to assess the expression of p16, STAT3, and glycoprotein130 (GP130) and autophagy-related proteins. Furthermore, human glomerular mesangial cells were administrated with tocilizumab (TCZ) and/or IL-6, and then the above indexes were tested again. Sclerotic glomerular density and glomerular sclerosis rate were significantly higher in individuals more than 40 years old, and they were strongly correlated with ages. Moreover, the expression of p16, STAT3, GP130, and p62 was significantly increased, while LC3II and autophagosome were statistically decreased in the aged-kidney. Glomeruli were hardly to stain with SA-ß-gal. For the in vitro experiments, we observed that IL-6 significantly increased p16, STAT3, GP130, and p62, induced higher SA-ß-gal staining, while downregulated LC3II and autophagosome. Furthermore, TCZ statistically reversed the effects of IL-6 on the above expression of proteins. Glomerular sclerosis rate might be one standard for natural renal aging, and IL-6/STAT3-mediated autophagy may participate in the development of age-related glomerulosclerosis.

STAT3: A key regulator in liver fibrosis.

Janus protein tyrosine kinase (JAK) has the ability to activate signal transducer and activator of transcription (STAT). STAT3 is a valued member of the JAK/STAT signaling pathway. In recent years, several studies have documented that STAT3 is closely related to the occurrence and development of liver fibrosis caused by various factors. Activation of STAT3 can play anti- or pro-inflammatory roles in the pathogenesis of liver fibrosis. This article reviewed the recent studies on STAT3 in the development of various liver fibrosis to find a more effective method to relieve and cure liver diseases, such as hepatitis B virus (HBV), non-alcoholic fatty liver disease (NAFLD), schistosomiasis, and chemical liver injury.

Overexpression of ribophorin II is required for viability of nasopharyngeal cancer cells by regulating JAK1/STAT3 activation.

OBJECTIVE: This study aimed to elucidate the role of ribophorin II (RPN2) in nasopharyngeal cancer (NPC) cell survival and death. RPN2 expression was upregulated in 22 human NPC specimens and 5-8F and CNE1 cells compared with that in adjacent normal tissues and normal nasopharyngeal NP69 cells. MATERIALS AND METHODS: CCK-8 and colony formation assays indicated that the silencing of RPN2 hindered the proliferation and growth of 5-8F and CNE1 cells. RESULTS: RPN2 expression was upregulated in 22 human NPC specimens as well as in 5-8F and CNE1 cells compared with that in adjacent normal tissues and NP69 cells. CCK-8 and colony formation assays indicated that the silencing of RPN2 reduced the proliferation and growth of 5-8F and CNE1 cells. Annexin V/PI flow cytometry and Bcl-2/Bax analysis showed that RPN2 silencing led to increased apoptosis. Moreover, JAK1 was found to interact with RPN2, and total JAK1, STAT3, and phosphorylated STAT3 levels were dramatically decreased in cells with RPN2 silencing. Furthermore, the nuclear localization of STAT3 was blocked by the silencing of RPN2. The administration of the STAT3 activator colivelin could offset the inhibitory effect of RPN2 silencing on the survival and apoptosis of NPC cells. CONCLUSION: RPN2 is upregulated in NPC tissues or cells, and RPN2 silencing repressed NPC cell proliferation and elicited apoptosis. RPN2 overexpression is possibly associated with JAK1/STAT3 silencing and activation. Finally, RPN2 represents a promising target for NPC treatment.

MFG-E8 alleviates oxygen-glucose deprivation-induced neuronal cell apoptosis by STAT3 regulating the selective polarization of microglia.

Background: Ischemic stroke is a complex pathological process, involving inflammatory reaction, energy metabolism disorder, free radical injury, cell apoptosis and other aspects. Accumulating evidences have revealed that MFG-E8 had a protective effect on multiple organ injuries. However, the comprehensive function and mechanism of MFG-E8 in ischemic brain remain largely unclear.Methods: BV-2 cells were treated with recombinant murine MFG-E8 (rmMFG-E8) or/and Colivelin TFA after exposing for 4 h with oxygen glucose deprivation (OGD). Cell viability and apoptosis were assessed by MTT assay and Flow cytometry. RT-qPCR and Western blot assays were applied to examine the expression levels of MFG-E8, apoptosis-related proteins and M1/M2 polarization markers.Results: Our results demonstrated that OGD significantly inhibited microglial viability and facilitated apoptosis. In addition, we found that OGD downregulated MFG-E8 expression, and MFG-E8 inhibited OGD-induced microglial apoptosis and promoted microglial M2 polarization. In terms of mechanism, we proved that MFG-E8 regulated OGD-induced microglial M1/M2 polarization by inhibiting p-STAT3 and SOCS3 expressions, which was reversed by STAT3 activator (Colivelin TFA). Finally, we verified MFG-E8 alleviated OGD-induced neuronal cell apoptosis by M2 polarization of BV-2 cells.Conclusions: We demonstrated that MFG-E8 reduced neuronal cell apoptosis by enhancing activation of microglia via STAT3 signaling. Therefore, we suggested that MFG-E8 might provide a novel mechanism for ischemic stroke.

Hemistepsin a Induces Apoptosis of Hepatocellular Carcinoma Cells by Downregulating STAT3.

Hemistepta lyrata (Bunge) Bunge is a biennial medicinal plant possessing beneficial effects including anti-inflammation, and hemistepsin A (HsA) isolated from H. lyrata has been known as a hepatoprotective sesquiterpene lactone. In this report, we explored the cytotoxic effects of H. lyrata on hepatocellular carcinoma (HCC) cells and investigated the associated bioactive compounds and their relevant mechanisms. From the viability results of HCC cells treated with various H. lyrata extracts, HsA was identified as the major compound contributing to the H. lyrata-mediated cytotoxicity. HsA increased expression of cleaved PARP and cells with Sub-G1 phase, Annexin V binding, and TUNEL staining, which imply HsA induces apoptosis. In addition, HsA provoked oxidative stress by decreasing the reduced glutathione/oxidized glutathione ratio and accumulating reactive oxygen species and glutathione-protein adducts. Moreover, HsA inhibited the transactivation of signal transducer and activator of transcription 3 (STAT3) by its dephosphorylation at Y705 and glutathione conjugation. Stable expression of a constitutive active mutant of STAT3 prevented the reduction of cell viability by HsA. Finally, HsA enhanced the sensitivity of sorafenib-mediated cytotoxicity by exaggerating oxidative stress and Y705 dephosphorylation of STAT3. Therefore, HsA will be a promising candidate to induce apoptosis of HCC cells via downregulating STAT3 and sensitizing conventional chemotherapeutic agents.

Revisiting bupropion anti-inflammatory action: involvement of the TLR2/TLR4 and JAK2/STAT3.

There are accumulating reports regarding poor response to common antidepressant therapy. Antidepressant resistance is often linked to inflammatory system activation and patients displaying inflammation prior to the treatment are less responsive to antidepressants. We hypothesized that the inefficacy of antidepressant therapy in some patients may be attributable to the drugs' inflammatory mode of action, which has been overlooked because of their substantial therapeutic benefit. Bupropion is a commonly prescribed antidepressant that is often used to treat seasonal affective disorders as well. Nevertheless, research suggests that bupropion causes inflammation and worsens depressive symptoms. Therefore, we investigated the impact of bupropion on cytokines of innate and adaptive immunity, as well as immune signaling pathways. We treated lipopolysaccharide (LPS)-stimulated human peripheral blood mononuclear cells (PBMCs) with different doses of bupropion. Pro-/anti-inflammatory cytokines [tumor necrosis factor alpha (TNFα), interleukin-1ß (IL-1ß), IL-17, and IL-10] were assessed at both transcriptional and translational levels as well as the involvement of JAK2 /STAT3, TLR2, and TLR4 signaling in this process. Bupropion reduced IL-17A, TNFα, and IL-1ß protein levels in the cultures. Nonetheless, bupropion increased IL-1ß (P < 0.0001), TNFα (P < 0.0001), and IL-17A (P < 0.05) mRNA levels. Treatment enhanced both IL-10 concentration (P < 0.0001) and gene expression (P < 0.0001). TLR2 (P < 0.0001), TLR4 (P < 0.0001), JAK2 (P < 0.0001), and STAT3 (P < 0.0001) gene expression also rose in response to bupropion. The findings imply that bupropion, particularly 50 µM and 100 µM, has pro-inflammatory effects and should be co-administered with anti-inflammatory medications, at least in patients with inflammatory conditions.

Oncogenic activation of the STAT3 pathway drives PD-L1 expression in natural killer/T-cell lymphoma.

Mature T-cell lymphomas, including peripheral T-cell lymphoma (PTCL) and extranodal NK/T-cell lymphoma (NKTL), represent a heterogeneous group of non-Hodgkin lymphomas with dismal outcomes and limited treatment options. To determine the extent of involvement of the JAK/STAT pathway in this malignancy, we performed targeted capture sequencing of 188 genes in this pathway in 171 PTCL and NKTL cases. A total of 272 nonsynonymous somatic mutations in 101 genes were identified in 73% of the samples, including 258 single-nucleotide variants and 14 insertions or deletions. Recurrent mutations were most frequently located in STAT3 and TP53 (15%), followed by JAK3 and JAK1 (6%) and SOCS1 (4%). A high prevalence of STAT3 mutation (21%) was observed specifically in NKTL. Novel STAT3 mutations (p.D427H, E616G, p.E616K, and p.E696K) were shown to increase STAT3 phosphorylation and transcriptional activity of STAT3 in the absence of cytokine, in which p.E616K induced programmed cell death-ligand 1 (PD-L1) expression by robust binding of activated STAT3 to the PD-L1 gene promoter. Consistent with these findings, PD-L1 was overexpressed in NKTL cell lines harboring hotspot STAT3 mutations, and similar findings were observed by the overexpression of p.E616K and p.E616G in the STAT3 wild-type NKTL cell line. Conversely, STAT3 silencing and inhibition decreased PD-L1 expression in STAT3 mutant NKTL cell lines. In NKTL tumors, STAT3 activation correlated significantly with PD-L1 expression. We demonstrated that STAT3 activation confers high PD-L1 expression, which may promote tumor immune evasion. The combination of PD-1/PD-L1 antibodies and STAT3 inhibitors might be a promising therapeutic approach for NKTL, and possibly PTCL.

Cyanidin prevents the hyperproliferative potential of fibroblast-like synoviocytes and disease progression via targeting IL-17A cytokine signalling in rheumatoid arthritis.

The hyperplastic phenotype of fibroblast-like synoviocytes (FLSs) plays an important role for synovitis, chronic inflammation and joint destruction in rheumatoid arthritis (RA). Interleukin 17A (IL-17A), a signature pro-inflammatory cytokine effectively influences the hyperplastic transformation of FLS cells and synovial pannus growth. IL-17A cytokine signalling participates in RA pathology by regulating an array of pro-inflammatory mediators and osteoclastogenesis. Cyanidin, a key flavonoid inhibits IL-17A/IL-17 receptor A (IL-17RA) interaction and alleviates progression and disease severity of psoriasis and asthma. However, the therapeutic efficacy of cyanidin on IL-17A cytokine signalling in RA remains unknown. In the present study, cyanidin inhibited IL-17A induced migratory and proliferative capacity of FLS cells derived from adjuvant-induced arthritis (AA) rats. Cyanidin treatment reduced IL-17A mediated reprogramming of AA-FLS cells to overexpress IL-17RA. In addition, significantly decreased expression of IL-17A dependent cyr61, IL-23, GM-CSF, and TLR3 were observed in AA-FLS cells in response to cyanidin. At the molecular level, cyanidin modulated IL-17/IL-17RA dependent JAK/STAT-3 signalling in AA-FLS cells. Importantly, cyanidin activated PIAS3 protein to suppress STAT-3 specific transcriptional activation in AA-FLS cells. Cyanidin treatment to AA rats attenuated clinical symptoms, synovial pannus growth, immune cell infiltration, and bone erosion. Cyanidin reduced serum level of IL-23 and GM-CSF and expression of Cyr 61 and TLR3 in the synovial tissue of AA rats. Notably, the level of p-STAT-3 protein was significantly decreased in the synovial tissue of AA rats treated with cyanidin. This study provides the first evidence that cyanidin can be used as IL-17/17RA signalling targeting therapeutic drug for the treatment of RA and this need to be investigated in RA patients.

IRF4 and STAT3 activities are associated with the imbalanced differentiation of T-cells in responses to inhalable particulate matters.

BACKGROUND: Particulate Matter (PM) is known to cause inflammatory responses in human. Although prior studies verified the immunogenicity of PM in cell lines and animal models, the effectors of PM exposure in the respiratory system and the regulators of the immunogenicity of PM is not fully elucidated. METHODS: To identify the potential effector of PM exposure in human respiratory system and to better understand the biology of the immunogenicity of PM, We performed gene-expression profiling of peripheral blood mononuclear cells from 171 heathy subjects in northern China to identify co-expressed gene modules associated with PM exposure. We inferred transcription factors regulating the co-expression and validated the association to T-cell differentiation in both primary T-cells and mice treated with PM. RESULTS: We report two transcription factors, IRF4 and STAT3, as regulators of the gene expression in response to PM exposure in human. We confirmed that the activation of IRF4 and STAT3 by PM is strongly associated with imbalanced differentiation of T-cells in the respiratory tracts in a time-sensitive manner in mouse. We also verified the consequential inflammatory responses of the PM exposure. Moreover, we show that the protein levels of phosphorylated IRF4 and STAT3 increase with PM exposure. CONCLUSIONS: Our study suggests the regulatory activities of IRF4 and STAT3 are associated with the Th17-mediated inflammatory responses to PM exposure in the respiratory tracts, which informs the biological background of the immunogenicity of particulate matters.

Neutralization of interleukin-9 ameliorates experimental stroke by repairing the blood-brain barrier via down-regulation of astrocyte-derived vascular endothelial growth factor-A.

Astrocytes mediate the destruction of the blood-brain barrier (BBB) during ischemic stroke (IS). IL-9 is a pleiotropic cytokine that we previously found to be highly expressed in peripheral blood mononuclear cells from patients with IS, and the presence of IL-9 receptors on astrocytes has been reported in the literature. Here, we detected the effect of IL-9 on astrocytes using an anti-IL-9-neutralizing antibody to treat rats with experimental stroke. Supernatants from astrocytes treated with or without oxygen-glucose deprivation and/or IL-9 were incubated with bEnd.3 cell monolayers after blocking the IL-9 receptor on the endothelium. Immunofluorescence staining and Western blot analyses were conducted to observe the change in tight junction proteins (TJPs) in bEnd.3 cells as well as the level of VEGF-A and possible signal pathways in astrocytes. We also applied middle cerebral artery occlusion (MCAO) models to determine the effect of anti-IL-9-neutralizing antibodies on IS. As a result, astrocyte-conditioned medium treated with IL-9 aggravated the disruption of the BBB accomplished by the degradation of TJPs in endothelial cells. In addition, IL-9 increased the level of VEGF-A in astrocytes, and blocking the effect of VEGF-A reversed the breakdown of the BBB. In the MCAO model, anti-IL-9-neutralizing antibody reduced the infarct volume and BBB destruction. Mechanistically, the anti-IL-9-neutralizing antibody repaired the damaged TJPs (zonula occludens 1, occludin, and claudin-5) and induced a decrease in VEGF-A expression in ischemic lateral brain tissue. In contrast, a local injection of recombinant murine IL-9 to the brain resulted in a marked up-regulation of VEGF-A in the striatum. In conclusion, anti-IL-9-neutralizing antibody can reduce the severity of IS partially by alleviating the destruction of the BBB via down-regulation of astrocyte-derived VEGF-A. This finding suggests that targeting IL-9 or VEGF-A could provide a new direction for the treatment of IS.-Tan, S., Shan, Y., Lin, Y., Liao, S., Zhang, B., Zeng, Q., Wang, Y., Deng, Z., Chen, C., Hu, X., Peng, L., Qiu, W., Lu, Z. Neutralization of IL-9 ameliorates experimental stroke by repairing the blood-brain barrier via down-regulation of astrocyte-derived vascular endothelial growth factor-A.

310 nm UV-LEDs attenuate imiquimod-induced psoriasis-like skin lesions in C57BL/6 mice and inhibit IL-22-induced STAT3 expression in HaCaT cells.

Ultraviolet light-emitting diodes (UV-LEDs) are a novel light source for phototherapy. This study aimed to evaluate the therapeutic effects of UV-LEDs on psoriasis. Importantly, 310 nm UV-LEDs have not been studied in psoriasis in vitro and in vivo. Effects due to 310 nm UV-LED and 311 nm narrowband ultraviolet B (NBUVB) irradiation were compared for suppressing IL-22-induced activation of STAT3 expression using cell viability assay, western blotting, and immunocytochemistry. C57BL/6 mice were topically treated with imiquimod (IMQ) for 6 consecutive days and degenerative changes were observed. Test groups were irradiated with a 310 nm UV-LED and 311 nm NBUVB. Phenotypic observations, histopathological examinations, and ELISA were conducted with skin and blood samples. STAT3-dependent IL-22 signalling and effects in keratinocytes are negatively regulated by the 310 nm UV-LED, which significantly ameliorated IMQ-induced psoriasis-like dermatitis development and reduced Th17 cytokine levels (IL-17A, IL-22) in serum and dorsal skin. Histopathological findings showed decreases in epidermal thickness and inflammatory T-cell infiltration in the UV-LED-irradiated groups. Quantitative PCR confirmed a UV radiation energy-dependent decrease in IL-17A and IL-22 mRNA levels. The results demonstrated that UV-LEDs had anti-inflammatory and immunoregulatory effects. So, UV-LED phototherapy inhibits psoriasis development by suppressing STAT3 protein and inflammatory cytokines and could be useful in treating psoriasis.