UMP-CMP kinase 2 inhibits ZIKV replication through activation of type I IFN signaling pathway.

Cytidine/uridine monophosphate kinase 2 (UMP-CMP kinase 2, CMPK2) has been reported as an antiviral interferon-stimulated gene (ISG). We previously observed that the expression of CMPK2 was significantly upregulated after Zika Virus (ZIKV) infection in A549 cells. However, the association and the underlying mechanisms between CMPK2 induction and ZIKV replication remain to be determined. We investigated the induction of CMPK2 during ZIKV infection and the effect of CMPK2 on ZIKV replication in A549, U251, Vero, IFNAR-deficient U5A and its parental 2fTGH cells, Huh7 and its RIG-I-deficient derivatives Huh7.5.1 cells. The activation status of Jak-STAT signaling pathway was determined by detecting the phosphorylation level of STAT1, the activity of interferon stimulated response element (ISRE) and the expression of several interferon stimulated genes (ISGs). We found that ZIKV infection induced CMPK2 expression through an IFNAR and RIG-I dependent manner. Overexpression of CMPK2 inhibited while CMPK2 knockdown promoted ZIKV replication in A549 and U251 cells. Mechanically, we found that CMPK2 overexpression increased IFNß expression and activated Jak/STAT signaling pathway as shown by the increased level of p-STAT1, enhanced activity of ISRE, and the upregulated expression of downstream ISGs. These findings suggest that ZIKV infection induced CMPK2 expression, which inhibited ZIKV replication and serves as a positive feedback regulator for IFN-Jak/STAT pathway.

Paradoxical cancer cell proliferation after FGFR inhibition through decreased p21 signaling in FGFR1-amplified breast cancer cells.

Fibroblast growth factors (FGFs) control various cellular functions through fibroblast growth factor receptor (FGFR) activation, including proliferation, differentiation, migration, and survival. FGFR amplification in ER + breast cancer patients correlate with poor prognosis, and FGFR inhibitors are currently being tested in clinical trials. By comparing three-dimensional spheroid growth of ER + breast cancer cells with and without FGFR1 amplification, our research discovered that FGF2 treatment can paradoxically decrease proliferation in cells with FGFR1 amplification or overexpression. In contrast, FGF2 treatment in cells without FGFR1 amplification promotes classical FGFR proliferative signaling through the MAPK cascade. The growth inhibitory effect of FGF2 in FGFR1 amplified cells aligned with an increase in p21, a cell cycle inhibitor that hinders the G1 to S phase transition in the cell cycle. Additionally, FGF2 addition in FGFR1 amplified cells activated JAK-STAT signaling and promoted a stem cell-like state. FGF2-induced paradoxical effects were reversed by inhibiting p21 or the JAK-STAT pathway and with pan-FGFR inhibitors. Analysis of patient ER + breast tumor transcriptomes from the TCGA and METABRIC datasets demonstrated a strong positive association between expression of FGF2 and stemness signatures, which was further enhanced in tumors with high FGFR1 expression. Overall, our findings reveal a divergence in FGFR signaling, transitioning from a proliferative to stemness state driven by activation of JAK-STAT signaling and modulation of p21 levels. Activation of these divergent signaling pathways in FGFR amplified cancer cells and paradoxical growth effects highlight a challenge in the use of FGFR inhibitors in cancer treatment.

Antiviral effect of palmatine against infectious bronchitis virus through regulation of NF-κB/IRF7/JAK-STAT signalling pathway and apoptosis.

1. Infectious bronchitis virus (IBV), a gamma-coronavirus, can infect chickens of all ages and leads to an acute contact respiratory infection. This study evaluated the anti-viral activity of palmatine, a natural non-flavonoid alkaloid, against IBV in chicken embryo kidney (CEK) cells.2. The half toxic concentration (CC50) of palmatine was 672.92 µM, the half inhibitory concentration (IC50) of palmatine against IBV was 7.76 µM and the selection index (SI) was 86.74.3. Mode of action assay showed that palmatine was able to directly inactivate IBV and inhibited the adsorption, penetration and intracellular replication of IBV.4. Palmatine significantly upregulated TRAF6, TAB1 and IKK-ß compared with the IBV-infected group, leading to the increased expressions of pro-inflammatory cytokines IL-1ß and TNF-α in the downstream NF-κB signalling pathway.5. Palmatine significantly up-regulated the levels of MDA5, MAVS, IRF7, IFN-α and IFN-ß in the IRF7 pathway, inducing type I interferon production. It up-regulated the expression of 2'5'-oligoadenylate synthase (OAS) in the JAK-STAT pathway.6. IBV infection induced cell apoptosis and palmatine-treatment delayed the process of apoptosis by regulation of the expression of apoptosis-related genes (BAX, BCL-2, CASPASE-3 and CASPASE-8).7. Palmatine could exert anti-IBV activity through regulation of NF-κB/IRF7/JAK-STAT signalling pathways and apoptosis, providing a theoretical basis for the utilisation of palmatine to treat IBV infection.

Forsythiaside A exhibits anti-migration and anti-inflammation effects in rheumatoid arthritis in vitro model.

BACKGROUND: Rheumatoid arthritis (RA) is a kind of systemic autoimmune disease, and the joint inflammation and cartilage destruction are the major features. Some traditional Chinese medicine have been discovered to exhibit regulatory roles in the treatment of RA. Forsythiaside A (FA) as an active ingredient isolated from forsythia suspensa has been discovered to participate into the regulation of some diseases through improving inflammation. However, the regulatory effects of FA on the progression of RA keep indistinct. METHODS: IL-1ß treatment (10 ng/mL) in MH7A cells was built to mimic RA in vitro (cell) model. The cell viability was examined through CCK-8 assay. The cell proliferation was detected through Edu assay. The levels of TNF-α, IL-6, and IL-8 were evaluated through ELISA. The protein expressions were measured through western blot. The cell apoptosis was assessed through flow cytometry. The cell migration and invasion abilities were tested through Transwell assay. RESULTS: In this study, it was revealed that the cell proliferation was strengthened after IL-1ß treatment (p < .001), but this effect was reversed after FA treatment in a dose-increasing manner (p < .05). Furthermore, FA suppressed inflammation in IL-1ß-triggered MH7A cells through attenuating the levels of TNF-α, IL-6, and IL-8 (p < .05). The cell apoptosis was lessened after IL-1ß treatment (p < .001), but this effect was rescued after FA treatment (p < .05). Besides, the cell migration and invasion abilities were both increased after IL-1ß treatment (p < .001), but these changes were offset after FA treatment (p < .05). Eventually, FA retarded the JAK/STAT pathway through reducing p-JAK/JAK and p-STAT/STAT levels (p < .01). CONCLUSION: Our study manifested that FA exhibited anti-migration and anti-inflammation effects in RA in vitro model (IL-1ß-triggered MH7A cells) through regulating the JAK/STAT pathway. This work hinted that FA can be an effective drug for RA treatment.

The role of JAK/STAT signaling pathway in cerebral ischemia-reperfusion injury and the therapeutic effect of traditional Chinese medicine: A narrative review.

Cerebral ischemia is a cerebrovascular disease with symptoms caused by insufficient blood or oxygen supply to the brain. When blood supplied is restored after cerebral ischemia, secondary brain injury may occur, which is called cerebral ischemia-reperfusion injury (CIRI). In this process, the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway plays an important role. It mediates neuroinflammation and participates in the regulation of physiological activities, such as cell proliferation, differentiation, and apoptosis. After CIRI, M1 microglia is activated and recruited by the damaged tissue. The inflammatory factors are produced by M1 microglia through the JAK/STAT pathway, eventually leading to cell apoptosis. Meanwhile, the JAK2/STAT3 signaling pathway and the expression of lipocalin-2 and caspase-3 could increase. In the pathway, phosphorylated JAK2 and phosphorylated STAT3 function of 2 ways. They not only promote the proliferation of neurons, but also affect the differentiation direction of neural stem cells by further acting on the Notch signaling pathway. Recently, traditional Chinese medicine (TCM) is a key player in CIRI, through JAK2, STAT3, STAT1 and their phosphorylation. Therefore, the review focuses on the JAK/STAT signaling pathway and its relationship with CIRI as well as the influence of the TCM on this pathway. It is aimed at providing the basis for future clinical research on the molecular mechanism of TCM in the treatment of CIRI.

Low-Density Lipoprotein Contributes to Endometrial Carcinoma Cell Proliferation, Migration, and Invasion by Activating the JAK-STAT Signaling Pathway.

Background: Cholesterol-rich low-density lipoprotein (LDL) particles have been demonstrated to regulate breast cancer cell proliferation and migration, but their biological function and relevant mechanisms in endometrial carcinoma (EC) remain unclear. Methods: Serum and tissue samples were collected from EC patients (n = 50) and patients with benign endometrial hyperplasia (n = 50). Ishikawa and RL95-2 cells were stimulated with different concentrations of LDL, followed by treatment with a JAK2 inhibitor (SD-1029). LDL concentrations were determined by ELISA. The in vitro biological behavior of cells was examined using the CCK-8 assay, EdU staining, and Transwell assay. The tumorigenicity of LDL in vivo was examined using a xenograft mouse model. western blotting, immunofluorescence, and immunohistochemistry studies were performed to measure related protein expression. Results: The LDL concentrations and levels of p-JAK2 and p-STAT3 expression were elevated in the clinical samples. Similar trends in expression were detected in EC cells after LDL stimulation. LDL treatment significantly promoted EC cell proliferation, migration, and invasion, and also upregulated p-JAK2 and p-STAT3 expression in a dose-dependent manner. Moreover, SD-1029 dramatically blocked the LDL-mediated effects on EC cells. Intravenous injection of LDLs promoted tumor growth in the xenograft nude mice, and also increased p-JAK2, p-STAT3, and Ki-67 expression, and downregulated caspase-3 expression. Conclusions: These findings indicate that LDLs exert an oncogenic effect in EC cells by activating the JAK/STAT signaling pathway, and also suggest the JAK/STAT pathway as a possible therapeutic target for EC.

Evolutionary, comparative, and functional analyses of STATs and regulation of the JAK-STAT pathway in lumpfish upon bacterial and poly(I:C) exposure.

Background: The Janus kinase/signal transducers and activators of transcription (JAK-STAT) system regulates several biological processes by affecting transcription of genes as a response to cytokines and growth factors. In the present study, we have characterized the STAT genes in lumpfish (Cyclopterus lumpus L.), belonging to the order Perciformes, and investigated regulation of the JAK-STAT signaling pathway upon exposure to bacteria (Vibrio anguillarum) and poly(I:C), the latter mimicking antiviral responses. Methods: Characterization and evolutionary analyses of the STATs were performed by phylogeny, protein domain, homology similarity and synteny analyses. Antibacterial and antiviral responses were investigated by performing KEGG pathway analysis. Results: We observed that lumpfish have stat1a, 2, 3, 4, 5a, 5b, and 6. Transcriptome-wide analyses showed that most components of the JAK-STAT pathway were present in lumpfish. il-6, il-10, il-21, iκBα and stat3 were upregulated 6 hours post exposure (hpe) against bacteria while type I interferons (IFNs), irf1, irf3, irf10, stat1 and 2 were upregulated 24 hpe against poly(I:C). Conclusions: Our findings shed light on the diversity and evolution of the STATs and the data show that the STAT genes are highly conserved among fish, including lumpfish. The transcriptome-wide analyses lay the groundwork for future research into the functional significance of these genes in regulating critical biological processes and make an important basis for development of prophylactic measure such as vaccination, which is highly needed for lumpfish since it is vulnerable for both bacterial and viral diseases.

A new triazolyl-indolo-quinoxaline induces apoptosis in gastric cancer cells by abrogating the STAT3/5 pathway through upregulation of PTPεC.

Signal transducer and activator of transcription 3 (STAT3) and STAT5 are the transcription factors that have been studied extensively in relevance to the development of cancers in humans. Suppression of either STAT3 or STAT5-mediated signaling events has been demonstrated to be effective in inducing cytotoxicity in cancer cells. Herein, new hybrids of triazolyl-indolo-quinoxaline are synthesized and examined for their effect on the activation of STAT3 and STAT5 pathways in gastric cancer (GC) cells. Among the newly synthesized compounds, 2,3-difluoro-6-((1-(3-fluorophenyl)-1H-1,2,3-triazol-5-yl)methyl)-6H-indolo[2,3-b]quinoxaline (DTI) displayed selective cytotoxicity against GC cells over their normal counterpart. Flow cytometric analysis, annexin-V-fluorescein isothiocyanate staining, terminal deoxynucleotidyl transferase dUTP nick end labeling assay, live and dead assay, and caspase activation experiments suggested DTI as a potent inducer of apoptosis. The mechanistic approach revealed that DTI imparts cytotoxicity via downregulating the phosphorylation of STAT3Y705 and STAT5Y694/699 . DTI significantly reduced the nuclear pool of STAT3/STAT5 and reduced the DNA interaction ability of STAT3/STAT5 as evidenced by immunofluorescence and electrophoretic mobility shift assay. Further investigation revealed that inhibitory effects towards STAT proteins were mediated through the suppression of upstream kinases such as JAK1, JAK2, and Src. Treatment of GC cells with pervanadate counteracted the DTI-driven STAT3/STAT5 inhibition suggesting the involvement of tyrosine phosphatase. Upon DTI exposure, there was a significant upregulation in the mRNA and protein expression of PTPεC, which is a negative regulator of the JAK-STAT pathway. Knockdown of PTPεC suppressed the DTI-induced STATs inhibition in GC cells. Taken together, triazolyl-indolo-quinoxaline is presented as a new inhibitor of the STAT3/STAT5 pathway in GC cells.

Potential drug repurposing of ruxolitinib to inhibit the JAK/STAT pathway for the treatment of patients with epithelial ovarian cancer.

AIM: This review aimed to describe the potential for therapeutic targeting of the JAK/STAT signaling pathway by repurposing the clinically-approved JAK inhibitor ruxolitinib in the patients with epithelial ovarian cancer (OC) setting. METHODS: We reviewed publications that focus on the inhibition of the JAK/STAT pathway in hematological and solid malignancies including OC. RESULTS: Preclinical studies showed that ruxolitinib effectively reduces OC cell viability and metastasis and enhances the anti-tumor activity of chemotherapy drugs. There are a number of recent clinical trials exploring the role of JAK/STAT inhibition in solid cancers including OC. Early results have not adequately supported efficacy in solid tumors. However, there are preclinical data and clinical studies supporting the use of ruxolitinib in combination with both chemotherapy and other targeted drugs in OC setting. CONCLUSION: Inflammatory conditions and persistent activation of the JAK/STAT pathway are associated with tumourigenesis and chemoresistance, and therapeutic blockade of this pathway shows promising results. For women with OC, clinical investigation exploring the role of ruxolitinib in combination with chemotherapy agents or other targeted therapeutics is warranted.

Four-Arm Polymer-Guided Formation of Curcumin-Loaded Flower-Like Porous Microspheres as Injectable Cell Carriers for Diabetic Wound Healing.

Stem cell injection is an effective approach for treating diabetic wounds; however, shear stress during injections can negatively affect their stemness and cell growth. Cell-laden porous microspheres can provide shelter for bone mesenchymal stem cells (BMSC). Herein, curcumin-loaded flower-like porous microspheres (CFPM) are designed by combining phase inversion emulsification with thermally induced phase separation-guided four-arm poly (l-lactic acid) (B-PLLA). Notably, the CFPM shows a well-defined surface topography and inner structure, ensuring a high surface area to enable the incorporation and delivery of a large amount of -BMSC and curcumin. The BMSC-carrying CFPM (BMSC@CFPM) maintains the proliferation, retention, and stemness of -BMSCs, which, in combination with their sustainable curcumin release, facilitates the endogenous production of growth/proangiogenic factors and offers a local anti-inflammatory function. An in vivo bioluminescence assay demonstrates that BMSC@CFPM can significantly increase the retention and survival of BMSC in wound sites. Accordingly, BMSC@CFPM, with no significant systemic toxicity, could significantly accelerate diabetic wound healing by promoting angiogenesis, collagen reconstruction, and M2 macrophage polarization. RNA sequencing further unveils the mechanisms by which BMSC@CFPM promotes diabetic wound healing by increasing -growth factors and enhancing angiogenesis through the JAK/STAT pathway. Overall, BMSC@CFPM represents a potential therapeutic tool for diabetic wound healing.

Roflumilast ameliorates diabetic nephropathy in rats through down-regulation of JAK/STAT signaling pathway.

Roflumilast is a potent selective inhibitor of the phosphodiesterase-4 enzyme which greatly manifest an anti-inflammatory activity in chronic obstructive pulmonary patients. Inflammation is a prominent factor in the prevalence of diabetic nephropathy, one of the most prevalent microvascular complications of Diabetes Mellitus. The present study was undertaken to assess the potential role of roflumilast in diabetic nephropathy. The model was developed by feeding a high-fat diet for four weeks and following streptozotocin (30 mg/kg) injection intraperitoneally. The rats with > 13.8 mmol/L blood glucose were treated with roflumilast (0.25, 0.5, 1 mg/kg) and standard metformin (100 mg/kg) orally once a day for eight weeks. Roflumilast (1 mg/kg) remarkably improved renal damage, indicated by an increase in 16% albumin, a decrease in 5% serum creatinine, 12% BUN, 19% HbA1c, and 34% blood glucose. It also significantly improves the oxidative stress levels, which was indicated by a decrease in 18% MDA level and an increase in GSH, SOD, and catalase by 6%, 4%, and 5%, respectively. In addition, Roflumilast (1 mg/kg) decreased the HOMA-IR index by 28% and increased the pancreatic ß-cells functioning by 30%. Moreover, significant improvement in histopathological abnormalities were observed in roflumilast treatment groups. Roflumilast treatment was shown to down-regulate the gene expressions of TNF-α (2.1-fold), NF-kB (2.3-fold), MCP-1 (2.5-fold), fibronectin (2.7-fold), collagen IV (2.7-fold), STAT 1(1.06-fold), and STAT 3 (1.20-fold) and upregulated the expression of the Nrf2 (1.43-fold) gene. Roflumilast manifested a potential role in diabetic nephropathy as a renoprotective agent. Roflumilast effectively down-regulates the JAK/STAT pathway and restores renal functions.

SOCS1-KIR Peptide in PEGDA Hydrogels Reduces Pro-Inflammatory Macrophage Activation.

Macrophages modulate the wound healing cascade by adopting different phenotypes such as pro-inflammatory (M1) or pro-wound healing (M2). To reduce M1 activation, the JAK/STAT pathway can be targeted by using suppressors of cytokine signaling (SOCS1) proteins. Recently a peptide mimicking the kinase inhibitory region (KIR) of SOCS1 has been utilized to manipulate the adaptive immune response. However, the utilization of SOCS1-KIR to reduce pro-inflammatory phenotype in macrophages is yet to be investigated in a biomaterial formulation. This study introduces a PEGDA hydrogel platform to investigate SOCS1-KIR as a macrophage phenotype manipulating peptide. Immunocytochemistry, cytokine secretion assays, and gene expression analysis for pro-inflammatory macrophage markers in 2D and 3D experiments demonstrate a reduction in M1 activation due to SOCS1-KIR treatment. The retention of SOCS1-KIR in the hydrogel through release assays and diffusion tests is demonstrated. The swelling ratio of the hydrogel also remains unaffected with the entrapment of SOCS1-KIR. This study elucidates how SOCS1-KIR peptide in PEGDA hydrogels can be utilized as an effective therapeutic for macrophage manipulation.

JAK-STAT pathway inhibitors in dermatology.

The JAK-STAT signaling pathway mediates important cellular processes such as immune response, carcinogenesis, cell differentiation, division and death. Therefore, drugs that interfere with different JAK-STAT signaling patterns have potential indications for various medical conditions. The main dermatological targets of JAK-STAT pathway inhibitors are inflammatory or autoimmune diseases such as psoriasis, vitiligo, atopic dermatitis and alopecia areata; however, several dermatoses are under investigation to expand this list of indications. As JAK-STAT pathway inhibitors should gradually occupy a relevant space in dermatological prescriptions, this review presents the main available drugs, their immunological effects, and their pharmacological characteristics, related to clinical efficacy and safety, aiming to validate the best dermatological practice.

Cyanidin-3-O-glucoside plays a protective role against renal ischemia/ reperfusion injury via the JAK/STAT pathway.

PURPOSE: To investigate the role of cyanidin-3-O-glucoside (C3G) in renal ischemia/reperfusion (I/R) injury and the potential mechanisms. METHODS: Mouse models were established by clamping the left renal vessels, and in vitro cellular models were established by hypoxic reoxygenation. RESULTS: Renal dysfunction and tissue structural damage were significantly higher in the I/R group. After treatment with different concentrations of C3G, the levels of renal dysfunction and tissue structural damage decreased at different levels. And its protective effect was most pronounced at 200 mg/kg. The use of C3G reduced apoptosis as well as the expression of endoplasmic reticulum stress (ERS)-related proteins. Hypoxia/reoxygenation (H/R)-induced apoptosis and ERS are dependent on oxidative stress in vitro. In addition, both AG490 and C3G inhibited the activation of JAK/STAT pathway and attenuated oxidative stress, ischemia-induced apoptosis and ERS. CONCLUSIONS: The results demonstrated that C3G blocked renal apoptosis and ERS protein expression by preventing reactive oxygen species (ROS) production after I/R via the JAK/STAT pathway, suggesting that C3G may be a potential therapeutic agent for renal I/R injury.

Increased reactive oxygen species lead to overactivation of platelets in essential thrombocythemia.

INTRODUCTION: Platelet function, rather than platelet count, plays a crucial role in thrombosis in essential thrombocythemia (ET). However, little is known about the abnormal function of platelets in ET. Here, we investigated the functional characteristics of platelets in ET hemostasis to explore the causes of ET platelet dysfunction and new therapeutic strategies for ET. MATERIALS AND METHODS: We analyzed platelet aggregation, activation, apoptosis, and reactive oxygen species (ROS) in ET patients and JAK2V617F-positive ET-like mice. The effects of ROS on platelet function and the underlying mechanism were investigated by inhibiting ROS using N-acetylcysteine (NAC). RESULTS: Platelet aggregation, activation, apoptosis, ROS, and clot retraction were elevated in ET. No significant differences were observed between ET patients with JAK2V617F or CALR mutations. Increased ROS activated the JAK-STAT pathway, which may further influence platelet function. Inhibition of platelet ROS by NAC reduced platelet aggregation, activation, and apoptosis, and prolonged bleeding time. Furthermore, NAC treatment reduced platelet count in ET-like mice by inhibiting platelet production from megakaryocytes. CONCLUSIONS: Elevated ROS in ET platelets resulted in enhanced platelet activation, function and increased risk of thrombosis. NAC offers a potential therapeutic strategy for reducing platelet count.

Spermatogenesis associated serine rich 2 like plays a prognostic factor and therapeutic target in acute myeloid leukemia by regulating the JAK2/STAT3/STAT5 axis.

BACKGROUND: Spermatogenesis associated serine rich 2 like (SPATS2L) was highly expressed in homoharringtonine (HHT) resistant acute myeloid leukemia (AML) cell lines. However, its role is little known in AML. The present study aimed to investigate the function of SPATS2L in AML pathogenesis and elucidate the underlying molecular mechanisms. METHODS: Overall survival (OS), event-free survival (EFS), relapse-free survival (RFS) were used to evaluate the prognostic impact of SPATS2L for AML from TCGA database and ourcohort. ShRNA was used to knockdown the expression of SPATS2L. Apoptosis was assessed by flow cytometry. The changes of proteins were assessed by Western blot(WB). A xenotransplantation mice model was used to evaluate in vivo growth and survival. RNA sequencing was performed to elucidate the molecular mechanisms underlying the role of SPATS2L in AML. RESULTS: SPATS2L expression increased with increasing resistance indexes(RI) in HHT-resistant cell lines we had constructed. Higher SPATS2L expression was observed in intermediate/high-risk patients than in favorable patients. Meanwhile, decreased SPATS2L expression was observed in AML patients achieving complete remission (CR). Multivariate analysis showed high SPATS2L expression was an independent poor predictor of OS, EFS, RFS in AML. SPATS2L knock down (KD) suppressed cell growth, induced apoptosis, and suppressed key proteins of JAK/STAT pathway, such as JAK2, STAT3, STAT5 in AML cells. Inhibiting SPATS2L expression markedly enhanced the pro-apoptotic effects of traditional chemotherapeutics (Ara-c, IDA, and HHT). CONCLUSIONS: High expression of SPATS2L is a poor prognostic factor in AML, and targeting SPATS2L may be a promising therapeutic strategy for AML patients.

JAK-STAT inhibition reduces endothelial prothrombotic activation and leukocyte-endothelial proadhesive interactions.

BACKGROUND: Vascular activation is characterized by increased proinflammatory, pro thrombotic, and proadhesive signaling. Several chronic and acute conditions, including Bcr-abl-negative myeloproliferative neoplasms (MPNs), graft-vs-host disease, and COVID-19 have been noted to have increased activation of the janus kinase (JAK)-signal transducer and downstream activator of transcription (STAT) pathways. Two notable inhibitors of the JAK-STAT pathway are ruxolitinib (JAK1/2 inhibitor) and fedratinib (JAK2 inhibitor), which are currently used to treat MPN patients. However, in some conditions, it has been noted that JAK inhibitors can increase the risk of thromboembolic complications. OBJECTIVES: We sought to define the anti-inflammatory and antithrombotic effects of JAK-STAT inhibitors in vascular endothelial cells. METHODS: We assessed endothelial activation in the presence or absence of ruxolitinib or fedratinib by using immunoblots, immunofluorescence, qRT-PCR, and function coagulation assays. Finally, we used endothelialized microfluidics perfused with blood from normal and JAK2V617F+ individuals to evaluate whether ruxolitinib and fedratinib changed cell adhesion. RESULTS: We found that both ruxolitinib and fedratinib reduced endothelial cell phospho-STAT1 and STAT3 signaling and attenuated nuclear phospho-NK-κB and phospho-c-Jun localization. JAK-STAT inhibition also limited secretion of proadhesive and procoagulant P-selectin and von Willebrand factor and proinflammatory IL-6. Likewise, we found that JAK-STAT inhibition reduced endothelial tissue factor and urokinase plasminogen activator expression and activity. CONCLUSIONS: By using endothelialized microfluidics perfused with whole blood samples, we demonstrated that endothelial treatment with JAK-STAT inhibitors prevented rolling of both healthy control and JAK2V617F MPN leukocytes. Together, these findings demonstrate that JAK-STAT inhibitors reduce the upregulation of critical prothrombotic pathways and prevent increased leukocyte-endothelial adhesion.

Oxymatrine ameliorates myocardial injury by inhibiting oxidative stress and apoptosis via the Nrf2/HO-1 and JAK/STAT pathways in type 2 diabetic rats.

The necessity of increasing the efficiency of organ preservation has encouraged researchers to explore the mechanisms underlying diabetes-related myocardial injuries. This study intended to evaluate the protective effects of oxymatrine (OMT) in myocardial injury caused by type 2 diabetes mellitus. A model of diabetic rats was established to simulate type 2 diabetes mellitus using an intraperitoneal injection of a single dose of 65 mg/kg streptozotocin with a high-fat and high-cholesterol diet, and diabetic rats were subsequently treated with OMT (60, 120 mg/kg) by gavage for 8 weeks. Thereafter, diabetic rats demonstrated notable decreases in left ventricular systolic pressure (LVSP), ±dp/dtmax, and in the activities of glutathione peroxidase, superoxide dismutase, and catalase. Moreover, we found notable increases in left ventricular end-diastolic pressure, fasting blood glucose, and malondialdehyde, as well as changes in cell apoptosis and decreased expression levels of Nrf2, HO-1, tyrosine protein kinase JAK (JAK), and signal transducer and transcription activator (STAT). Treatment with OMT alleviated all of the measured parameters. Collectively, these findings suggest that activation of the Nrf2/HO-1 and inhibition of the JAK/STAT signaling are involved in mediating the cardioprotective effects of OMT and also highlight the benefits of OMT in ameliorating myocardial injury in diabetic rats.

Growth hormone inhibits the JAK/STAT3 pathway by regulating SOCS1 in endometrial cells in vitro: a clue to enhance endometrial receptivity in recurrent implantation failure.

Recurrent implantation failure (RIF) is defined as failure to achieve clinical pregnancy after at least 3 transfers of good-quality embryos by natural or artificial means. RIF is often a complex problem with a wide variety of etiologies and mechanisms as well as treatment options. In this study, using immunohistochemistry and Western blot, we demonstrated that the expression of leukemia inhibitory factor (LIF), Janus kinase 1 (JAK1), and signal transducer and activator of transcription 3 (STAT3) was increased, while that of suppressor of cytokine signaling 1 (SOCS1) was decreased in RIF patients. Growth hormone (GH) administration proved to have positive effects on embryo implantation in RIF patients, but the action mechanism of GH has not been elucidated yet. To this aim, we studied the effects of GH on the proliferation in vitro of endometrial adenocarcinoma Ishikawa cells. GH stimulated the expression of LIF and SOCS1, and through SOCS1 inhibits the expression of phosphorylated STAT3, and finally inhibits the occurrence of RIF. Excessive phosphorylation of STAT can lead to decreased endometrial receptivity and abnormal embryo implantation. We also examined the effects of LIF overexpression and an LIF inhibitor (EC330) on the JAK/STAT pathway. LIF promoted cell proliferation, and the up-regulation of LIF increased the expression of SOCS1 and JAK1/STAT3 pathway-related genes in Ishikawa cells. As GH can inhibit the JAK1/STAT3 pathway through LIF, we hypothesize that upregulating SOCS1 may be a potential approach to treat RIF at the molecular level. GH can inhibit the JAK1/STAT3 pathway through LIF, up-regulating SOCS1 to treat RIF at the molecular level.

Inhibition of the JAK/STAT Pathway With Baricitinib Reduces the Multiple Organ Dysfunction Caused by Hemorrhagic Shock in Rats.

OBJECTIVE: The aim of this study was to investigate (a) the effects of the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway inhibitor (baricitinib) on the multiple organ dysfunction syndrome (MODS) in a rat model of hemorrhagic shock (HS) and (b) whether treatment with baricitinib attenuates the activation of JAK/STAT, NF-κB, and NLRP3 caused by HS. BACKGROUND: Posttraumatic MODS, which is in part due to excessive systemic inflammation, is associated with high morbidity and mortality. The JAK/STAT pathway is a regulator of numerous growth factor and cytokine receptors and, hence, is considered a potential master regulator of many inflammatory signaling processes. However, its role in trauma-hemorrhage is unknown. METHODS: An acute HS rat model was performed to determine the effect of baricitinib on MODS. The activation of JAK/STAT, NF-κB, and NLRP3 pathways were analyzed by western blotting in the kidney and liver. RESULTS: We demonstrate here for the first time that treatment with baricitinib (during resuscitation following severe hemorrhage) attenuates the organ injury and dysfunction and the activation of JAK/STAT, NF-κB, and NLRP3 pathways caused by HS in the rat. CONCLUSIONS: Our results point to a role of the JAK/STAT pathway in the pathophysiology of the organ injury and dysfunction caused by trauma/hemorrhage and indicate that JAK inhibitors, such as baricitinib, may be repurposed for the treatment of the MODS after trauma and/or hemorrhage.