Janus kinases in immune cell signaling

Bone marrow mesenchymal stem cells-derived exosomes suppress miRNA-5189-3p to increase fibroblast-like synoviocyte apoptosis via the BATF2/JAK2/STAT3 signaling pathway

Ankylosing spondylitis (AS) is characterized by inflammation of the sacroiliac joint and the attachment point of the spine. Herein, we aimed to investigate the effect of bone marrow mesenchymal stem cells (BMSCs)-derived exosomes on apoptosis of fibroblast-like synoviocytes (FLSs) and explored its molecular mechanism. Exosomes were isolated from BMSCs and verified by transmission electron microscope and nanoparticle tracking analysis. FLSs were isolated and co-incubated with BMSC exosomes. Cell apoptosis was assessed using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling analysis and flow cytometry. The results showed that BMSC exosomes increased apoptosis of FLSs. MiR-5189-3p was downregulated, while basic leucine zipper transcription factor ATF-like 2 (BATF2) was upregulated in FLSs by treatment of BMSC exosomes. As a direct target of miR-5189-3p, BATF2 inactivates the JAK2/STAT3 pathway. MiR-5189-3p suppressed apoptosis of FLSs and BATF2 exerted an opposite effect. In conclusion, BMSCs-derived exosomes suppress miR-5189-3p to facilitate the apoptosis of FLSs via the BATF2/JAK2/STAT3 signaling pathway, which facilitates the understanding of the therapeutic effect of BMSCs on AS and the underlying molecular mechanism.

Topical Administration of 0.3% Tofacitinib Suppresses M1 Macrophage Polarization and Allograft Corneal Rejection by Blocking STAT1 Activation in the Rat Cornea

Purpose

M1 macrophages can promote corneal allograft rejection (CGR). Inhibiting M1 macrophage polarization by the JAK/STAT1 pathway may be a new strategy to prevent CGR. Tofacitinib, a potent pan-JAK inhibitor, can inhibit JAK/STAT activation. Here, we investigated the inhibitory effects of tofacitinib on M1 macrophage polarization and its therapeutic effect on rat CGR.

Methods

Corneal allograft transplantation was performed and administrated with 0.3% tofacitinib in rats. The corneal allografts were assessed clinically. The corneas were detected for M1 macrophages, lymphatic vessels, and inflammatory cytokine expression using immunohistochemistry and real-time polymerase chain reaction (PCR). Dendritic cells (DCs) in ipsilateral cervical lymph nodes were detected by flow cytometry. The effect and mechanism of tofacitinib on macrophages were explored by real-time PCR, enzyme-linked immunoassay, and western blot analysis in vitro.

Results

The results showed that topical administration of 0.3% tofacitinib significantly prolonged corneal graft survival. Tofacitinib-treated corneal allografts displayed a proportionate decrease in M1 macrophages and reduced lymphatic vessel density with fewer DCs in rat ipsilateral cervical lymph nodes. Tofacitinib reduced the mRNA expression of inflammatory cytokines, including iNOS, MCP-1, TNF-α, IL-6, IL-1β, and VEGF-C, and inhibited STAT1 activation in rat corneal grafts. In addition, tofacitinib suppressed M1 macrophage polarization via STAT1 activation after IFN-γ and lipopolysaccharide stimulation in vitro.

Conclusions

Tofacitinib could suppress M1 macrophage polarization and subsequently delay CGR by inhibiting STAT1 activation. The data indicate that tofacitinib is an effective drug for CGR.

Translational Relevance

This study provided evidence that topical administration of 0.3% tofacitinib may be a novel clinical strategy to prevent CGR.

Herpes Zoster and Vaccination Strategies in Inflammatory Bowel Diseases: A Practical Guide

Herpes zoster is a painful dermatomal cutaneous eruption resulting from reactivation of the latent varicella-zoster virus. Patients with inflammatory bowel diseases have an increased risk of shingles compared with the general population and this risk can be increased with the use of immunosuppressive therapy. Live zoster vaccine and recombinant zoster vaccine have shown efficacy for the prevention of herpes zoster. The recombinant zoster vaccine seems to offer greater efficacy and long-term protection profile compared with the life zoster vaccine. However, their use in clinical practice still is unclear and updated vaccination recommendations are lacking. This review discusses the risk for shingles in patients with inflammatory bowel diseases, available vaccines, and their efficacy and safety profiles. We also provide guidance on who, when, and how to vaccinate for herpes zoster in routine clinical practice among patients with inflammatory bowel diseases.

Abi1 mediates airway smooth muscle cell proliferation and airway remodeling via Jak2/STAT3 signaling

Asthma is a complex pulmonary disorder with multiple pathological mechanisms. A key pathological feature of chronic asthma is airway remodeling, which is largely attributed to airway smooth muscle (ASM) hyperplasia that contributes to thickening of the airway wall and further drives asthma pathology. The cellular processes that mediate ASM cell proliferation are not completely elucidated. Using multiple approaches, we demonstrate that the adapter protein Abi1 (Abelson interactor 1) is upregulated in ∼50% of ASM cell cultures derived from patients with asthma. Loss-of-function studies demonstrate that Abi1 regulates the activation of Jak2 (Janus kinase 2) and STAT3 (signal transducers and activators of transcription 3) as well as the proliferation of both nonasthmatic and asthmatic human ASM cell cultures. These findings identify Abi1 as a molecular switch that activates Jak2 kinase and STAT3 in ASM cells and demonstrate that a dysfunctional Abi1-associated pathway contributes to the progression of asthma.

Functional characterization of NPM1-TYK2 fusion oncogene

Gene fusions are known to drive many human cancers. Therefore, the functional characterization of newly discovered fusions is critical to understanding the oncobiology of these tumors and to enable therapeutic development. NPM1–TYK2 is a novel fusion identified in CD30 + lymphoproliferative disorders, and here we present the functional evaluation of this fusion gene as an oncogene. The chimeric protein consists of the amino-terminus of nucleophosmin 1 (NPM1) and the carboxyl-terminus of tyrosine kinase 2 (TYK2), including the kinase domain. Using in vitro lymphoid cell transformation assays and in vivo tumorigenic xenograft models we present direct evidence that the fusion gene is an oncogene. NPM1 fusion partner provides the critical homodimerization needed for the fusion kinase constitutive activation and downstream signaling that are responsible for cell transformation. As a result, our studies identify NPM1–TYK2 as a novel fusion oncogene and suggest that inhibition of fusion homodimerization could be a precision therapeutic approach in cutaneous T-cell lymphoma patients expressing this chimera.

Multiomic profiling of checkpoint inhibitor-treated melanoma: Identifying predictors of response and resistance, and markers of biological discordance

We concurrently examine the whole genome, transcriptome, methylome, and immune cell infiltrates in baseline tumors from 77 patients with advanced cutaneous melanoma treated with anti-PD-1 with or without anti-CTLA-4. We show that high tumor mutation burden (TMB), neoantigen load, expression of IFNγ-related genes, programmed death ligand expression, low PSMB8 methylation (therefore high expression), and T cells in the tumor microenvironment are associated with response to immunotherapy. No specific mutation correlates with therapy response. A multivariable model combining the TMB and IFNγ-related gene expression robustly predicts response (89% sensitivity, 53% specificity, area under the curve [AUC], 0.84); tumors with high TMB and a high IFNγ signature show the best response to immunotherapy. This model validates in an independent cohort (80% sensitivity, 59% specificity, AUC, 0.79). Except for a JAK3 loss-of-function mutation, for patients who did not respond as predicted there is no obvious biological mechanism that clearly explained their outlier status, consistent with intratumor and intertumor heterogeneity in response to immunotherapy.

Proteomimetics of Natural Regulators of JAK-STAT Pathway: Novel Therapeutic Perspectives

The JAK-STAT pathway is a crucial cellular signaling cascade, including an intricate network of Protein-protein interactions (PPIs) responsible for its regulation. It mediates the activities of several cytokines, interferons, and growth factors and transduces extracellular signals into transcriptional programs to regulate cell growth and differentiation. It is essential for the development and function of both innate and adaptive immunities, and its aberrant deregulation was highlighted in neuroinflammatory diseases and in crucial mechanisms for tumor cell recognition and tumor-induced immune escape. For its involvement in a multitude of biological processes, it can be considered a valuable target for the development of drugs even if a specific focus on possible side effects associated with its inhibition is required. Herein, we review the possibilities to target JAK-STAT by focusing on its natural inhibitors as the suppressor of cytokine signaling (SOCS) proteins. This protein family is a crucial checkpoint inhibitor in immune homeostasis and a valuable target in immunotherapeutic approaches to cancer and immune deficiency disorders.

Ranked binding energies of residues and data fusion to identify the active and selective pyrimidine-based Janus kinases 3 (JAK3) inhibitors

The idea of using ranked binding energies of residues and data fusion are presented here for the first time as a valuable tool to classify active and selective inhibitors. Selective inhibitors of JAK3 can inhibit inflammatory cytokine while preventing targeting other subtypes of JAK1 and JAK2. Herein, we report a novel way to identify both active JAK3 and selective JAK1/JAK3 and JAK2/JAK3 inhibitors using the effective activity and selectivity classifications. The most important residues (top 10) responsible for the inhibition mechanism are sorted from high to low energies, which are considered as variables in the classification process. In addition, the ranked energies of ligands' heteroatoms (top 5), ranked energies of hydrogen bonds (top 5) and important molecular descriptors (top 10) were used to construct different data fusion possibilities. It is shown that the proposed data fusion strategy can increase the accuracy of the activity classification to 100% and the selectivity classification to 96.4%. The proposed strategies represented in this paper can help medicinal or pharmaceutical chemist in evaluation of both active and selective inhibitors before synthesizing new pharmaceuticals.

Regulation of Tripartite Motif-Containing Proteins on Immune Response and Viral Evasion

Tripartite motif-containing proteins (TRIMs), exhibiting ubiquitin E3 ligase activity, are involved in regulation of not only autophagy and apoptosis but also pyrotosis and antiviral immune responses of host cells. TRIMs play important roles in modulating signaling pathways of antiviral immune responses via type I interferon, NF-κB, Janus kinase/signal transducer and activator of transcription (JAK/STAT), and Nrf2. However, viruses are able to antagonize TRIM activity or evenly utilize TRIMs for viral replication. This communication presents the current understanding of TRIMs exploited by viruses to evade host immune response.

Treatment of Inflammatory Bowel Disease: A Comprehensive Review

Inflammatory bowel disease (IBD), as a global disease, has attracted much research interest. Constant research has led to a better understanding of the disease condition and further promoted its management. We here reviewed the conventional and the novel drugs and therapies, as well as the potential ones, which have shown promise in preclinical studies and are likely to be effective future therapies. The conventional treatments aim at controlling symptoms through pharmacotherapy, including aminosalicylates, corticosteroids, immunomodulators, and biologics, with other general measures and/or surgical resection if necessary. However, a considerable fraction of patients do not respond to available treatments or lose response, which calls for new therapeutic strategies. Diverse therapeutic options are emerging, involving small molecules, apheresis therapy, improved intestinal microecology, cell therapy, and exosome therapy. In addition, patient education partly upgrades the efficacy of IBD treatment. Recent advances in the management of IBD have led to a paradigm shift in the treatment goals, from targeting symptom-free daily life to shooting for mucosal healing. In this review, the latest progress in IBD treatment is summarized to understand the advantages, pitfalls, and research prospects of different drugs and therapies and to provide a basis for the clinical decision and further research of IBD.

Immune Dysregulation and Infectious Complications in MPN Patients Treated With JAK Inhibitors

BCR-ABL1-negative myeloproliferative neoplasms are burdened by a reduced life expectancy mostly due to an increased risk of thrombo-hemorrhagic events, fibrotic progression/leukemic evolution, and infectious complications. In these clonal myeloid malignancies, JAK2V617F is the main driver mutation, leading to an aberrant activation of the Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway. Therefore, its inhibition represents an attractive therapeutic strategy for these disorders. Several JAK inhibitors have entered clinical trials, including ruxolitinib, the first JAK1/2 inhibitor to become commercially available for the treatment of myelofibrosis and polycythemia vera. Due to interference with the JAK-STAT pathway, JAK inhibitors affect several components of the innate and adaptive immune systems such as dendritic cells, natural killer cells, T helper cells, and regulatory T cells. Therefore, even though the clinical use of these drugs in MPN patients has led to a dramatic improvement of symptoms control, organ involvement, and quality of life, JAK inhibitors–related loss of function in JAK-STAT signaling pathway can be a cause of different adverse events, including those related to a condition of immune suppression or deficiency. This review article will provide a comprehensive overview of the current knowledge on JAK inhibitors’ effects on immune cells as well as their clinical consequences, particularly with regards to infectious complications.

Antirheumatic Drugs against COVID-19 from the Perspective of Rheumatologists

Coronavirus disease 2019 (COVID-19) remains a global threat to humanity. Its pathogenesis and different phases of disease progression are being elucidated under the pandemic. Active viral replication activates various immune cells and produces large amounts of inflammatory cytokines, which leads to the cytokine storm, a major cause of patient death. Therefore, viral inhibition is expected to be the most effective early in the course of the disease, while immunosuppressive treatment may be useful in the later stages to prevent disease progression. Based on the pathophysiology of rheumatic diseases, various immunomodulatory and immunosuppressive drugs are used for the diseases. Due to their mechanism of action, the antirheumatic drugs, including hydroxychloroquine, chloroquine, colchicine, calcineurin inhibitors (e.g., cyclosporine A and tacrolimus), glucocorticoids, cytokines inhibitors, such as anti-tumor necrosis factor-α (e.g., infliximab), anti-interleukin (IL)-6 (e.g., tocilizumab, sarilumab, and siltuximab), anti-IL-1 (e.g., anakinra and canakinumab) and Janus kinase inhibitors (e.g., baricitinib and tofacitinib), cytotoxic T lymphocyte-associated antigen 4 blockade agents (e.g., abatacept), and phosphodiesterase 4 inhibitors (e.g., apremilast), have been tried as a treatment for COVID-19. In this review, we discuss the mechanisms of action and clinical impact of these agents in the management of COVID-19.

Integrated transcriptome analysis of immune-related mRNAs and microRNAs in Macrobrachium rosenbergii infected with Spiroplasma eriocheiris

Macrobrachium rosenbergii (M. rosenbergii), is a major aquaculture species in China and Southeast Asia. However, infection with Spiroplasma eriocheiris (S. eriocheiris) has caused huge economic losses to the cultivation of M. rosenbergii. Currently, there are few reports on the immune response mechanism of M. rosenbergii that are infected with S. eriocheiris. To clarify the immune response mechanism of M. rosenbergii infected with S. eriocheiris, the key immune genes which respond to the infection with the pathogen and the regulation of related microRNAs (miRNAs) on them were identified. In this study, the mRNA and miRNA transcriptome of hepatopancreas of M. rosenbergii at different infection stages were analyzed using high-throughput sequencing and qRT-PCR. In the mRNA transcriptome, 27,703 and 33,402 genes were expressed in healthy and susceptible M. rosenbergii, respectively. By digital gene-expression profiling analysis, 23,929 and 24,325 genes were expressed, and 223 and 373 genes were significantly up-regulated and down-regulated, respectively. A total of 145 key genes related to Toll, IMD, JAK/STAT and MAPK were excavated from the transcriptome. In the miRNA transcriptome, 549 miRNAs (Conserved: 41, PN-type: 83, PC-type: 425) were sequenced, of which 87 were significantly up-regulated and 23 were significantly down-regulated. Among the related immune pathways, there are 259 miRNAs involved in the regulation of target genes in the Toll and IMD pathways, 231 JAK/STAT pathways and 122 MAPK pathways. qRT-PCR differential detection of immune-related miRNAs and mRNAs showed that 22 miRNAs with significant differences (P < 0.05) such as mro-miR-100, PC-mro-3p-27 and PN-mro-miR-316 had corresponding regulatory relationships with 22 important immune genes such as TLR2, TLR3, TLR4, TLR5, MyD88, Pelle and Relish in different stages after infection. In this study, the immune genes and related regulatory miRNAs of M. rosenbergii in response to S. eriocheiris infection were obtained. The results can provide basic data to further reveal the immune defense mechanism of M. rosenbergii against S. eriocheiris infection.

Quantification of the janus kinase 1 inhibitor upadacitinib in human plasma by LC-MS/MS

Upadacitinib is a selective janus-kinase-1 inhibitor effective in the treatment of autoimmune related diseases like rheumatoid arthritis or psoriatic arthritis. Here, we described a LC-MS/MS method for the quantification of upadacitinib in human plasma applicable for therapeutic drug monitoring. Pexidartinib was used as internal standard. Plasma samples were prepared by acidic protein precipitation and the analytes were separated on a C-18 reversed phase column. Detection took place by tandem mass spectroscopy after ionization in the positive mode and collision induced fragmentation at m/z 381 → 256, 213 for upadacitinib and m/z 418 → 258, 165 for pexidartinib. The calibration function was linear in the range of 0.15 - 150 ng/mL. Precisions and accuracies were better than 10% in intra- as well as inter-day evaluations. The method was applied in therapeutic drug monitoring of patients undergoing treatment for rheumatoid arthritis with the standard dose of 15 mg upadacitinib extended release formulation once daily. At steady state, we found trough levels of 4.13 (3.51 - 11.0) ng/mL, which is comparable to values found in healthy volunteers receiving the same dose (2.8 ± 1.2 ng/mL).

Ruxolitinib Ameliorates Airway Hyperresponsiveness and Lung Inflammation in a Corticosteroid-Resistant Murine Model of Severe Asthma

Asthma prevalence has increased considerably over the decades and it is now considered as one of the most common chronic disorders in the world. While the current anti-asthmatic therapies are effective for most asthma patients, there are 5-10% subjects whose disease is not controlled by such agents and they account for about 50% of the asthma-associated healthcare costs. Such patients develop severe asthma (SA), a condition characterized by a dominant Th1/Th17 cytokine response that is accompanied by Type 2 (T2)-low endotype. As JAK (Janus Kinase) signaling is very important for the activation of several cytokine pathways, we examined whether inhibition of JAKs might lessen the clinical and laboratory manifestations of SA. To that end, we employed a recently described murine model that recapitulates the complex immune response identified in the airways of human SA patients. To induce SA, mice were sensitized with house dust mite extract (HDME) and cyclic (c)-di-GMP and then subsequently challenged with HDME and a lower dose of c-di-GMP. In this model, treatment with the JAK inhibitor, Ruxolitinib, significantly ameliorated all the features of SA, including airway hyperresponsiveness and lung inflammation as well as total IgE antibody titers. Thus, these studies highlight JAKs as critical targets for mitigating the hyper-inflammation that occurs in SA and provide the framework for their incorporation into future clinical trials for patients that have severe or difficult-to manage asthma.

Target-Based Small Molecule Drug Discovery Towards Novel Therapeutics for Inflammatory Bowel Diseases

Inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), is a class of severe and chronic diseases of the gastrointestinal (GI) tract with recurrent symptoms and significant morbidity. Long-term persistence of chronic inflammation in IBD is a major contributing factor to neoplastic transformation and the development of colitis-associated colorectal cancer. Conversely, persistence of transmural inflammation in CD is associated with formation of fibrosing strictures, resulting in substantial morbidity. The recent introduction of biological response modifiers as IBD therapies, such as antibodies neutralizing tumor necrosis factor (TNF)-α, have replaced nonselective anti-inflammatory corticosteroids in disease management. However, a large proportion (~40%) of patients with the treatment of anti-TNF-α antibodies are discontinued or withdrawn from therapy because of (1) primary nonresponse, (2) secondary loss of response, (3) opportunistic infection, or (4) onset of cancer. Therefore, the development of novel and effective therapeutics targeting specific signaling pathways in the pathogenesis of IBD is urgently needed. In this comprehensive review, we summarize the recent advances in drug discovery of new small molecules in preclinical or clinical development for treating IBD that target biologically relevant pathways in mucosal inflammation. These include intracellular enzymes (Janus kinases, receptor interacting protein, phosphodiesterase 4, IκB kinase), integrins, G protein-coupled receptors (S1P, CCR9, CXCR4, CB2) and inflammasome mediators (NLRP3), etc. We will also discuss emerging evidence of a distinct mechanism of action, bromodomain-containing protein 4, an epigenetic regulator of pathways involved in the activation, communication, and trafficking of immune cells. We highlight their chemotypes, mode of actions, structure-activity relationships, characterizations, and their in vitro/in vivo activities and therapeutic potential. The perspectives on the relevant challenges, new opportunities, and future directions in this field are also discussed.

Selective Tyrosine Kinase 2 Inhibition for Treatment of Inflammatory Bowel Disease: New Hope on the Rise

Conventional systemic and biologic agents are the mainstay of inflammatory bowel disease (IBD) management; however, many of these agents are associated with loss of clinical response, highlighting the need for effective, novel targeted therapies. Janus kinase (JAK) 1-3 and tyrosine kinase 2 (TYK2) mediate signal transduction events downstream of multiple cytokine receptors that regulate targeted gene transcription, including the interleukin-12, interleukin-23, and type I interferon receptors for TYK2. This review summarizes the role of TYK2 signaling in IBD pathogenesis, the differential selectivity of TYK2 inhibitors, and the potential clinical implications of TYK2 inhibition in IBD. A PubMed literature review was conducted to identify studies of JAK1-3 and TYK2 inhibitors in IBD and other immune-mediated inflammatory diseases. Key efficacy and safety information was extracted and summarized. Pan-JAK inhibitors provide inconsistent efficacy in patients with IBD and are associated with toxicities resulting from a lack of selectivity at therapeutic dosages. Selective inhibition of TYK2 signaling via an allosteric mechanism, with an agent that binds to the regulatory (pseudokinase) domain, may reduce potential toxicities typically associated with JAK1-3 inhibitors. Deucravacitinib, a novel, oral, selective TYK2 inhibitor, and brepocitinib and PF-06826647, TYK2 inhibitors that bind to the active site in the catalytic domain, are in development for IBD and other immune-mediated inflammatory diseases. Allosteric TYK2 inhibition is more selective than JAK1-3 inhibition and has the potential to limit toxicities typically associated with JAK1-3 inhibitors. Future studies will be important in establishing the role of selective, allosteric TYK2 inhibition in the management of IBD.

Molecular and clinical effects of selective TYK2 inhibition with deucravacitinib in psoriasis

BACKGROUND

Psoriasis, a chronic inflammatory disease dependent on the interleukin (IL)-23/T helper cell 17 (Th17) pathway, is initiated through plasmacytoid dendritic cell activation and type I interferon induction in the skin. Deucravacitinib, a selective tyrosine kinase 2 (TYK2) inhibitor, blocks IL-23, IL-12, and type I interferon signaling in cellular assays.

OBJECTIVE

Investigate changes in IL-23/Th17- and type I interferon-pathway biomarkers and gene responses, and measures of selectivity for TYK2 over Janus kinases (JAKs) 1-3, in patients with moderate to severe psoriasis receiving deucravacitinib.

METHODS

Deucravacitinib was evaluated in a randomized, placebo-controlled, dose-ranging trial. Biopsies from non-lesional (Day 1) and lesional skin (Days 1, 15, and 85) were assessed for changes in IL-23/IL-12 and type I interferon pathway biomarkers by quantitative reverse-transcription polymerase chain reaction, RNA sequencing, and immunohistochemistry. Laboratory markers were measured in blood. Percent change from baseline in Psoriasis Area and Severity Index (PASI) score was assessed.

RESULTS

IL-23 pathway biomarkers in lesional skin returned toward non-lesional levels dose-dependently with deucravacitinib. Interferon and IL-12 pathway genes were normalized. Markers of keratinocyte dysregulation, keratin-16, and β-defensin genes approached non-lesional levels with effective dosages. Select laboratory parameters impacted by JAK1-3 inhibition were unaffected by deucravacitinib. Greater improvements in PASI scores, correlated with biomarker changes, were seen with the highest dosages of deucravacitinib versus lower dosages or placebo.

CONCLUSION

Robust clinical efficacy with deucravacitinib treatment was associated with decreases in IL-23/Th17 and interferon pathway biomarkers. The lack of effect seen on biomarkers specific to JAK1-3 inhibition support selectivity of deucravacitinib for TYK2; larger studies are needed to further confirm.

An insight into crosstalk among multiple signaling pathways contributing to epileptogenesis

Despite the years of research, epilepsy remains uncontrolled in one-third of afflicted individuals and poses a health and economic burden on society. Currently available anti-epileptic drugs mainly target the excitatory-inhibitory imbalance despite targeting the underlying pathophysiology of the disease. Recent research focuses on understanding the pathophysiologic mechanisms that lead to seizure generation and on possible new treatment avenues for preventing epilepsy after a brain injury. Various signaling pathways, including the mechanistic target of rapamycin (mTOR) pathway, mitogen-activated protein kinase (MAP-ERK) pathway, JAK-STAT pathway, wnt/β-catenin signaling, cAMP pathway, and jun kinase pathway, have been suggested to play an essential role in this regard. Recent work suggests that the mTOR pathway intervenes epileptogenesis and proposes that mTOR inhibitors may have antiepileptogenic properties for epilepsy. In the same way, several animal studies have indicated the involvement of the Wnt signaling pathway in neurogenesis and neuronal death induced by seizures in different phases (acute and chronic) of seizure development. Various studies have also documented the activation of JAK-STAT signaling in epilepsy and cAMP involvement in epileptogenesis through CREB (cAMP response element-binding protein). Although studies are there, the mechanism for how components of these pathways mediate epileptogenesis requires further investigation. This review summarises the current role of various signaling pathways involved in epileptogenesis and the crosstalk among them. Furthermore, we will also discuss the mechanical base for the interaction between these pathways and how these interactions could be a new emerging promising target for future epilepsy therapies.

A review of JAK-STAT signalling in the pathogenesis of spondyloarthritis and the role of JAK inhibition

Spondyloarthritis (SpA) comprises a group of chronic inflammatory diseases with overlapping clinical, genetic and pathophysiological features including back pain, peripheral arthritis, psoriasis, enthesitis and dactylitis. Several cytokines are involved in the pathogenesis of SpA, variously contributing to each clinical manifestation. Many SpA-associated cytokines, including IL-23, IL-17, IL-6, type I/II interferon and tumour necrosis factor signal directly or indirectly via the Janus kinase (JAK)–signal transducer and activator of transcription pathway. JAK signalling also regulates development and maturation of cells of the innate and adaptive immune systems. Accordingly, disruption of this signalling pathway by small molecule oral JAK inhibitors can inhibit signalling implicated in SpA pathogenesis. Herein we discuss the role of JAK signalling in the pathogenesis of SpA and summarize the safety and efficacy of JAK inhibition by reference to relevant SpA clinical trials.

Second-Generation Jak2 Inhibitors for Advanced Prostate Cancer: Are We Ready for Clinical Development?

Simple Summary

Prostate Cancer (PC) is currently estimated to affect 1 in 9 men and is the second leading cause of cancer in men in the US. While androgen deprivation therapy, which targets the androgen receptor, is one of the front-line therapies for advanced PC and for recurrence of organ-confined PC treated with surgery, lethal castrate-resistant PC develops consistently in patients. PC is a multi-focal cancer with different grade carcinoma areas presenting simultaneously. Jak2-Stat5 signaling pathway has emerged as a potentially highly effective molecular target in PCs with positive areas for activated Stat5 protein. Activated Jak2-Stat5 signaling can be readily targeted by the second-generation Jak2-inhibitors that have been developed for myeloproliferative and autoimmune disorders and hematological malignancies. In this review, we analyze and summarize the Jak2 inhibitors that are currently in preclinical and clinical development.

Abstract

Androgen deprivation therapy (ADT) for metastatic and high-risk prostate cancer (PC) inhibits growth pathways driven by the androgen receptor (AR). Over time, ADT leads to the emergence of lethal castrate-resistant PC (CRPC), which is consistently caused by an acquired ability of tumors to re-activate AR. This has led to the development of second-generation anti-androgens that more effectively antagonize AR, such as enzalutamide (ENZ). However, the resistance of CRPC to ENZ develops rapidly. Studies utilizing preclinical models of PC have established that inhibition of the Jak2-Stat5 signaling leads to extensive PC cell apoptosis and decreased tumor growth. In large clinical cohorts, Jak2-Stat5 activity predicts PC progression and recurrence. Recently, Jak2-Stat5 signaling was demonstrated to induce ENZ-resistant PC growth in preclinical PC models, further emphasizing the importance of Jak2-Stat5 for therapeutic targeting for advanced PC. The discovery of the Jak2V617F somatic mutation in myeloproliferative disorders triggered the rapid development of Jak1/2-specific inhibitors for a variety of myeloproliferative and auto-immune disorders as well as hematological malignancies. Here, we review Jak2 inhibitors targeting the mutated Jak2V617F vs. wild type (WT)-Jak2 that are currently in the development pipeline. Among these 35 compounds with documented Jak2 inhibitory activity, those with potency against WT-Jak2 hold strong potential for advanced PC therapy.

The Antimicrobial Peptide Human β-Defensin-3 Accelerates Wound Healing by Promoting Angiogenesis, Cell Migration, and Proliferation Through the FGFR/JAK2/STAT3 Signaling Pathway

In addition to its antimicrobial activity, the skin-derived antimicrobial peptide human β-defensin-3 (hBD-3) promotes keratinocyte proliferation and migration to initiate the wound healing process; however, its effects on fibroblasts, which are the major cell type responsible for wound healing, remain unclear. We investigated the role of hBD-3 in cell migration, proliferation and production of angiogenic growth factors in human fibroblasts and evaluated the in vivo effect of hBD-3 on promoting wound healing and angiogenesis. Following hBD-3 treatment, the mouse wounds healed faster and showed accumulation of neutrophils and macrophages in the early phase of wound healing and reduction of these phagocytes 4 days later. hBD-3-treated wounds also displayed an increased number of fibroblasts and newly formed vessels compared to those of the control mice. Furthermore, the expression of various angiogenic growth factors was increased in the hBD-3-treated wounds. Additionally, in vitro studies demonstrated that hBD-3 enhanced the secretion of angiogenic growth factors such as fibroblast growth factor, platelet-derived growth factor and vascular endothelial growth factor and induced the migration and proliferation of human fibroblasts. The hBD-3-mediated activation of fibroblasts involves the fibroblast growth factor receptor 1 (FGFR1)/Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathways, as evidenced by the inhibitory effects of pathway-specific inhibitors. We indeed confirmed that hBD-3 enhanced the phosphorylation of FGFR1, JAK2 and STAT3. Collectively, the current study provides novel evidence that hBD-3 might be a potential candidate for the treatment of wounds through its ability to promote wound healing, angiogenesis and fibroblast activation.

TYK2 inhibition and its potential in the treatment of chronic inflammatory immune diseases

Immune-mediated chronic inflammatory diseases have emerged as a leading cause of morbidity and mortality in Western countries over the last decades. Although multiple putative factors have been suspected to be causally related to the diseases, their overarching etiology remains unknown. This review article summarizes the current state of scientific knowledge and understanding of the role of non-receptor tyrosine kinases, with a special focus on the Janus kinase TYK2 in autoimmune and immune mediated diseases as well as on the clinical properties of its inhibition. A panel of experts in the field discussed the scientific evidence and molecular rationale for TYK2 inhibition and its clinical application. Reviewing this meeting, we aim at providing an integrated overview of the clinical profile of TYK2 inhibition and its potential in targeted pharmacological therapy of chronic autoimmune and immune-mediated diseases, with a special focus on inflammatory diseases of the skin.

Role of Janus Kinase Inhibitors in Therapy of Psoriasis

Janus kinases inhibitors are molecules that target Janus kinases-signal transducers and activators of transcription (JAK/STAT). They inhibit this intracellular signal pathway, blocking the gene transcription of crucial proinflammatory cytokines that play a central role in the pathogenesis of many inflammatory and autoimmune diseases, including psoriasis. This process reduces psoriatic inflammation. The JAK inhibitors are divided into two generations. The first generation of JAK inhibitors blocks two or more different Janus kinases. The second generation is more specified and blocks only one type of Janus kinase and has less side effects than the first generation. Tofacitinib, ruxolitinib and baricitinib belong to first generation JAK inhibitors and decernotinib and filgotinib belong to second group. This narrative review summarizes the role of Janus kinase inhibitors in the therapy of psoriasis. Oral JAK inhibitors show promise for efficacy and safety in the treatment of psoriasis. Studies to date do not indicate that JAK inhibitors are superior to recent biologic drugs in terms of efficacy. However, JAK inhibitors, due to their lack of increased incidence of side effects compared to other biologic drugs, can be included in the psoriasis treatment algorithm because they are orally taken. Nevertheless, further studies are needed to evaluate long-term treatment effects with these drugs.

Differentiating Psoriatic Arthritis from Osteoarthritis and Rheumatoid Arthritis: A Narrative Review and Guide for Advanced Practice Providers

Psoriatic arthritis (PsA) is a chronic inflammatory disease that affects multiple organ systems and is characterized by skin and joint manifestations. PsA is frequently undiagnosed and/or misdiagnosed, especially because of the similarities in clinical presentation shared with other arthritic diseases, including rheumatoid arthritis (RA) and osteoarthritis (OA). An accurate and timely diagnosis of PsA is crucial to prevent delays in optimal treatment, which can lead to irreversible joint damage and increased functional disability. Patients are usually seen by a number of different healthcare providers on their path to a diagnosis of PsA, including advanced practice providers (APPs). This review provides a comprehensive overview of the characteristic features that can be used to facilitate the differentiation of PsA from RA and OA. Detailed information on clinical manifestations, biomarkers, radiologic features, and therapeutic recommendations for PsA included here can be applied in routine clinical settings to provide APPs with the confidence and knowledge to recognize and refer patients more accurately to rheumatologists for management of patients with PsA.

Treatment of inflammatory bowel diseases: focusing on biologic agents and new therapies

Background: The treatment of inflammatory bowel diseases has evolved with the development of anti-tumor necrosis factor agents. Despite the long-term effectiveness, many patients experience primary non-response, secondary loss of response, or intolerance. Therefore, the development of new drugs that act on different inflammatory pathways has become necessary. This review focuses on biologic agents and new therapies for the treatment of inflammatory bowel diseases.Current Concepts: Vedolizumab, a gut-selective agent that targets α4β7 integrin is effective in both ulcerative colitis and Crohn’s disease. Ustekinumab is a monoclonal antibody that binds to p40 subunit of interleukin-12/interleukin-23. Ustekinumab is available for the treatment of Crohn’s disease and ulcerative colitis. Tofacitinib is the first Janus kinase inhibitor approved for the treatment of ulcerative colitis. The advantage of tofacitinib is an oral prescription medicine and has rapid action.Discussion and Conclusion: Since vedolizumab, ustekinumab and tofacitinib are effective agents for the treatment of inflammatory bowel diseases, positioning of old and new biologic agents and small molecules should be determined. The safety and efficacy of novel and emerging drugs needs to be evaluated in patients with inflammatory bowel disease.

SARS-CoV-2 Disrupts Proximal Elements in the JAK-STAT Pathway

SARS-CoV-2 can infect multiple organs, including lung, intestine, kidney, heart, liver, and brain. The molecular details of how the virus navigates through diverse cellular environments and establishes replication are poorly defined. Here, we generated a panel of phenotypically diverse, SARS-CoV-2-infectible human cell lines representing different body organs and performed longitudinal survey of cellular proteins and pathways broadly affected by the virus. This revealed universal inhibition of interferon signaling across cell types following SARS-CoV-2 infection. We performed systematic analyses of the JAK-STAT pathway in a broad range of cellular systems, including immortalized cells and primary-like cardiomyocytes, and found that SARS-CoV-2 targeted the proximal pathway components, including Janus kinase 1 (JAK1), tyrosine kinase 2 (Tyk2), and the interferon receptor subunit 1 (IFNAR1), resulting in cellular desensitization to type I IFN. Detailed mechanistic investigation of IFNAR1 showed that the protein underwent ubiquitination upon SARS-CoV-2 infection. Furthermore, chemical inhibition of JAK kinases enhanced infection of stem cell-derived cultures, indicating that the virus benefits from inhibiting the JAK-STAT pathway. These findings suggest that the suppression of interferon signaling is a mechanism widely used by the virus to evade antiviral innate immunity, and that targeting the viral mediators of immune evasion may help block virus replication in patients with COVID-19. IMPORTANCE SARS-CoV-2 can infect various organs in the human body, but the molecular interface between the virus and these organs remains unexplored. In this study, we generated a panel of highly infectible human cell lines originating from various body organs and employed these cells to identify cellular processes commonly or distinctly disrupted by SARS-CoV-2 in different cell types. One among the universally impaired processes was interferon signaling. Systematic analysis of this pathway in diverse culture systems showed that SARS-CoV-2 targets the proximal JAK-STAT pathway components, destabilizes the type I interferon receptor though ubiquitination, and consequently renders the infected cells resistant to type I interferon. These findings illuminate how SARS-CoV-2 can continue to propagate in different tissues even in the presence of a disseminated innate immune response.

Systematic Review on the Efficacy and Safety of Oral Janus Kinase Inhibitors for the Treatment of Atopic Dermatitis

Background: Atopic dermatitis is a chronic, relapsing and remitting disease that can be difficult to treat despite a recently approved biologic therapy targeting IL-4/IL-13 receptor. Oral janus kinase inhibitors (JAKi) represent a novel therapeutic class of targeted therapy to treat moderate-to-severe atopic dermatitis (AD). Objective: To review the efficacy, safety, and pharmacokinetic characteristics of oral JAKi in the treatment of AD. Methods: A PRISMA systematic review was conducted using MEDLINE, EMBASE (Ovid), and PubMed databases for studies assessing the efficacy, safety, and/or pharmacokinetic properties of oral forms of JAKi in the treatment of AD in pediatric or adult populations from inception to June 2021. Results: 496 papers were reviewed. Of 28 articles that underwent full text screening, 11 met our inclusion criteria for final qualitative review. Four studies examined abrocitinib; three studies examined baricitinib; three examined upadacitinib and one examined gusacitinib (ASN002). Significant clinical efficacy and a reassuring safety profile was reported for all JAKi agents reviewed. Rapid symptom control was reported for abrocitinib, baricitinib and upadacitinib. Limitations: Given the relatively limited evidence for each JAKi and the differences in patient eligibility criteria between studies, the data was not deemed suitable for a meta-analysis at this time. Conclusion: Given their ability to achieve rapid symptom control with a reassuring safety profile, we recommend considering the use of JAKi as a reliable systemic treatment option for adult patients with moderate-to-severe AD, who are unresponsive to topical or skin directed treatments.

Immunomodulation and immunotherapeutics of COVID-19

Severe acute respiratory syndrome coronavirus-2 causes coronavirus disease 2019, a pandemic which was originated from Wuhan city of China. The pandemic has affected millions of people worldwide. The pathogenesis of SARS-CoV-2 is characterized by a cytokine storm in the blood (cytokinemia) and tissues, especially the lungs. One of the major repercussions of this inflammatory process is the endothelial injury-causing intestinal bleeding, coagulopathy, and thromboembolism which result in various sudden and unexpected post-COVID complications including kidney failure, myocardial infarction, or multiorgan failure. In this review, we have summarized the immune responses, biochemical changes, and inflammatory responses in the human body after infection with the SARS-CoV-2 virus. The increased amount of inflammatory cytokines, chemokines, and involvement of complement proteins in inflammatory reaction increase the risk of occurrence of disease.

Prognostic values and clinical relationship of TYK2 in laryngeal squamous cell cancer

ABSTRACT

Laryngeal squamous cell cancer (LSCC) is the second most common head and neck cancer with the increasing mortality. The tyrosine kinase 2 (TYK2) has previously been reported to play an important role in various cancers excepting LSCC. We used available data from the cancer genome atlas program (TCGA), gene expression omnibus, and gene expression profiling interactive analysis (GEPIA) to evaluate the role of TYK2 in LSCC.The difference of TYK2 expression level between normal and tumor samples was analyzed based on TCGA, gene expression omnibus, and GEPIA databases. The relationship between clinical features and TYK2 were analyzed using the Wilcoxon signed-rank test. We applied Cox regression and the Kaplan-Meier method to finding which clinical characteristics is associated with overall survival. Also, we used GEPIA database to validate the relationship between TYK2 and overall survival. At last, we performed gene set enrichment analysis based on TCGA data set.The expression level of TYK2 in LSCC was significantly associated with gender, lymph node status and metastasis (P-values <.05). Kaplan-Meier survival analysis, as same as GEPIA validation, demonstrated that LSCC with TYK2-low had a worse prognosis than that with TYK2-high. The univariate analysis showed that TYK2-high correlated significantly with a better overall survival (hazard ratio: 0.351, 95% confidence interval: 0.194-0.637, P < .001). The multivariate analysis revealed that TYK2 remained independently associated with overall survival (hazard ratio: 0.36, 95% confidence interval: 0.185-0.699, P = .003). Gene set enrichment analysis shows that Janus kinases-STAT signaling pathway, p53 signalling pathway and natural killer cell mediated cytotoxicity, etc are enriched in TYK2 high expression phenotype.Gene TYK2 may be a potential prognostic molecular marker for LSCC. Moreover, the Janus kinases-STAT signaling pathway and p53 signaling pathway are probably the key pathway associated with TYK2 in LC.

TYK2 in Cancer Metastases: Genomic and Proteomic Discovery

Advances in genomic analysis and proteomic tools have rapidly expanded identification of biomarkers and molecular targets important to cancer development and metastasis. On an individual basis, personalized medicine approaches allow better characterization of tumors and patient prognosis, leading to more targeted treatments by detection of specific gene mutations, overexpression, or activity. Genomic and proteomic screens by our lab and others have revealed tyrosine kinase 2 (TYK2) as an oncogene promoting progression and metastases of many types of carcinomas, sarcomas, and hematologic cancers. TYK2 is a Janus kinase (JAK) that acts as an intermediary between cytokine receptors and STAT transcription factors. TYK2 signals to stimulate proliferation and metastasis while inhibiting apoptosis of cancer cells. This review focuses on the growing evidence from genomic and proteomic screens, as well as molecular studies that link TYK2 to cancer prevalence, prognosis, and metastasis. In addition, pharmacological inhibition of TYK2 is currently used clinically for autoimmune diseases, and now provides promising treatment modalities as effective therapeutic agents against multiple types of cancer.

Abrocitinib induction, randomized withdrawal, and retreatment in patients with moderate-to-severe atopic dermatitis: Results from the JAK1 Atopic Dermatitis Efficacy and Safety (JADE) REGIMEN phase 3 trial

BACKGROUND

The heterogeneous course of moderate-to-severe atopic dermatitis necessitates treatment flexibility.

OBJECTIVE

We evaluated the maintenance of abrocitinib-induced response with continuous abrocitinib treatment, dose reduction or withdrawal, and response to treatment reintroduction following flare (JAK1 Atopic Dermatitis Efficacy and Safety [JADE] REGIMEN: National Clinical Trial 03627767).

METHODS

Patients with moderate-to-severe atopic dermatitis responding to open-label abrocitinib 200 mg monotherapy for 12 weeks were randomly assigned in a 1:1:1 ratio to blinded abrocitinib (200 or 100 mg) or placebo for 40 weeks. Patients experiencing flare received rescue treatment (abrocitinib 200 mg plus topical therapy).

RESULTS

Of 1233 patients, 798 responders to induction (64.7%) were randomly assigned. The flare probability during maintenance was 18.9%, 42.6%, and 80.9% with abrocitinib 200 mg, abrocitinib 100 mg, and placebo, respectively. Among patients with flare in the abrocitinib 200 mg, abrocitinib 100 mg, and placebo groups, 36.6%, 58.8%, and 81.6% regained investigator global assessment 0/1 response, respectively, and 55.0%, 74.5%, and 91.8% regained eczema area and severity index response, respectively, with rescue treatment. During maintenance, 63.2% and 54.0% of patients receiving abrocitinib 200 and 100 mg, respectively, experienced adverse events.

LIMITATIONS

The definition of protocol-defined flare was not established, limiting the generalizability of findings.

CONCLUSION

Induction treatment with abrocitinib was effective; most responders continuing abrocitinib did not flare. Rescue treatment with abrocitinib plus topical therapy effectively recaptured response.

Comparative effectiveness and safety of non-tumour necrosis factor biologics and Janus kinase inhibitors in patients with active rheumatoid arthritis showing insufficient response to tumour necrosis factor inhibitors: A Bayesian network meta-analysis of randomized controlled trials

WHAT IS KNOWN AND OBJECTIVE

Both biologic and Janus kinase (JAK) inhibitor therapies have demonstrated substantial effectiveness in placebo-controlled studies in patients with active rheumatoid arthritis (RA) showing inadequate responses to tumour necrosis factor (TNF) inhibitors. The purpose of this study was to determine the relative effectiveness and safety of non-TNF biologics and JAK inhibitors in patients with RA showing insufficient response to TNF inhibitors.

METHODS

A Bayesian network meta-analysis incorporating direct and indirect data from randomized controlled trials (RCTs) was used to investigate the effectiveness and safety of non-TNF biologics (abatacept, rituximab, tocilizumab, salirumab and sirukumab) and JAK inhibitors (tofacitinib, baricitinib, upadacitinib and filgotinib) in patients with RA showing insufficient response to TNF inhibitors.

RESULTS

Nine RCTs, evaluating 3577 patients for 12 weeks fulfilled the inclusion requirements. JAK inhibitors and non-TNF biologics achieved a significant American College of Rheumatology 20% (ACR20) response relative to the placebo. The ranking probability based on the surface under the cumulative ranking curve (SUCRA) showed that JAK inhibitor treatment was most likely to achieve the highest ACR20 response rate, followed by non-TNF biologics and placebo. The ACR50 rate displayed similar patterns as the ACR20 response rate, but non-TNF biologics have a higher value than JAK inhibitors based on the ACR70 response rate. Adverse events did not reach statistical significance nor did serious adverse events when looking at safety over 12 weeks. The confidence intervals overlap, and there is no clinical significance to these safety data, even compared with placebo.

WHAT IS NEW AND CONCLUSION

Both non-TNF biologics and JAK inhibitors have similar effects in patients with active RA that are refractory to anti-TNF treatment, and there were no differences with regard to safety among the treatments.

Safety of Tofacitinib in a Real-World Cohort of Patients With Ulcerative Colitis

BACKGROUND & AIMS

Adverse events (AEs) including reactivation of herpes zoster (HZ) and venous thromboembolism (VTE) have been reported from clinical trials of tofacitinib in ulcerative colitis (UC). We investigated the incidence rates of AEs in a real-world study of UC patients given tofacitinib.

METHODS

We collected data from 260 patients with UC in the Tofacitinib Real-world Outcomes in Patients with ulceratIve colitis and Crohn's disease consortium study, performed at 6 medical centers in the United States. Patients were followed up for a median of 6 months (interquartile range, 2.7-11.5 mo). AEs were captured using a standardized data collection instrument before study initiation and at weeks 8, 16, 26, 39, and 52. Serious AEs were defined as life-threatening or resulting in a hospitalization, disability, or discontinuation of therapy. Logistic regression was performed to examine risk factors for AEs.

RESULTS

AEs occurred in 41 patients (15.7%); most were infections (N = 13; 5.0%). The incidence rate of any AE was 27.2 (95% CI, 24.4-30.7 per 100 patient-years of follow-up evaluation). Fifteen were serious AEs (36.6% of AEs), and tofacitinib was discontinued for 12 patients (4.6% of cohort). The incidence rates of serious AEs was 10.0 (95% CI, 8.9-11.2 per 100 patient-years of follow-up evaluation). Five patients developed HZ infection and 2 developed VTE (all receiving 10 mg tofacitinib, twice per day).

CONCLUSIONS

Real-world safety signals for tofacitinib are similar to those for clinical trials, with AEs reported from almost 16% of patients. HZ infection and VTE occurred in patients receiving 10 mg tofacitinib twice per day. These results support dose de-escalation after induction therapy, to reduce the risk of AEs.

The Atlantic salmon's stress- and immune-related transcriptional responses to moderate hypoxia, an incremental temperature increase, and these challenges combined

The marine environment is predicted to become warmer, and more hypoxic, and these conditions may negatively impact the health and survival of coastal fish species, including wild and farmed Atlantic salmon (Salmo salar). Thus, we examined how: (1) moderate hypoxia (∼70% air saturation) at 12°C for 3 weeks; (2) an incremental temperature increase from 12°C to 20°C (at 1°C week-1) followed by 4 weeks at 20°C; and (3) treatment "2" combined with moderate hypoxia affected transcript expression in the liver of post-smolts as compared to control conditions (normoxia, 12°C). Specifically, we assessed the expression of 45 genes related to the heat shock response, oxidative stress, apoptosis, metabolism and immunity using a high-throughput qPCR approach (Fluidigm Biomark™ HD). The expression profiles of 27 "stress"-related genes indicated that: (i) moderate hypoxia affected the expression of several stress genes at 12°C; (ii) their expression was impacted by 16°C under normoxic conditions, and this effect increased until 20°C; (iii) the effects of moderate hypoxia were not additive to those at temperatures above 16°C; and (iv) long-term (4 weeks) exposure to 20°C, with or without hypoxia, resulted in a limited acclimatory response. In contrast, the expression of 15 immune-related genes was not greatly affected until temperatures reached 20°C, and this effect was particularly evident in fish exposed to the added challenge of hypoxia. These results provide valuable information on how these two important environmental factors affect the "stress" physiology and immunology of Atlantic salmon, and we identify genes that may be useful as hypoxia and/or temperature biomarkers in salmonids and other fishes.

Rapid Improvement of Itch Associated With Atopic Dermatitis With Abrocitinib Is Partially Independent of Overall Disease Improvement: Results From Pooled Phase 2b and 3 Monotherapy Studies

Supplemental digital content is available in the text.

Background

Itch, the most bothersome symptom in atopic dermatitis, is largely mediated by pruritogenic cytokines via Janus kinase 1 signaling in cutaneous sensory neurons.

Objectives

The aims of the study were to assess the magnitude and rapidity of itch relief with the Janus kinase 1 selective inhibitor abrocitinib and to evaluate the extent to which the effect of abrocitinib on itch relief is independent of overall disease improvement.

Methods

Pooled data from 1 phase 2b (NCT02780167) and 2 phase 3 (NCT03349060, NCT03575871) double-blind, randomized, placebo-controlled monotherapy trials in moderate to severe atopic dermatitis (N = 942) were analyzed.

Results

Abrocitinib produced significant and clinically meaningful itch relief versus placebo from week 2 through week 12 (end of treatment) that was associated with marked sleep and quality-of-life improvements. Mean percentage reductions in itch scores 24 hours after the first dose were greater for both abrocitinib doses (200 and 100 mg) versus placebo. Itch improvement occurred regardless of baseline itch severity, sex, race, body mass index, or Investigator Global Assessment response, suggesting that abrocitinib-associated itch relief is at least partially independent of overall disease improvement.

Conclusions

Abrocitinib showed a rapid and profound antipruritic effect, partially independent of improvement in overall disease.

Tyrosine kinase 2 and Janus kinase‒signal transducer and activator of transcription signaling and inhibition in plaque psoriasis

Plaque psoriasis is a common, chronic, systemic, immune-mediated inflammatory disease. The Janus kinase-signal transducer and activator of transcription pathway plays a major role in intracellular cytokine signaling in inflammatory processes involved in psoriasis. Although Janus kinase (JAK) 1-3 inhibitors have demonstrated efficacy in patients with moderate-to-severe psoriasis, safety concerns persist and no JAK inhibitor has received regulatory approval to treat psoriasis. Thus, an opportunity exists for novel oral therapies that are safe and efficacious in psoriasis. Tyrosine kinase 2 (TYK2) is a member of the JAK family of kinases and regulates signaling and functional responses downstream of the interleukin 12, interleukin 23, and type I interferon receptors. Deucravacitinib, which is an oral, selective inhibitor that binds to the regulatory domain of TYK2, and brepocitinib (PF-06700841) and PF-06826647, which are topical and oral TYK2 inhibitors, respectively, that bind to the active (adenosine triphosphate-binding) site in the catalytic domain, are in development for psoriasis. Selective, allosteric inhibition of TYK2 signaling may reduce the potential for toxicities associated with pan-JAK inhibitors. This article reviews Janus kinase-signal transducer and activator of transcription and TYK2 signaling and the efficacy and safety of JAK inhibitors in psoriasis to date, focusing specifically on TYK2 inhibitors.

Dual targeting of cytokine storm and viral replication in COVID-19 by plant-derived steroidal pregnanes: An in silico perspective

The high morbidity and mortality rate of Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) infection arises majorly from the Acute Respiratory Distress Syndrome and "cytokine storm" syndrome, which is sustained by an aberrant systemic inflammatory response and elevated pro-inflammatory cytokines. Thus, phytocompounds with broad-spectrum anti-inflammatory activity that target multiple SARS-CoV-2 proteins will enhance the development of effective drugs against the disease. In this study, an in-house library of 117 steroidal plant-derived pregnanes (PDPs) was docked in the active regions of human glucocorticoid receptors (hGRs) in a comparative molecular docking analysis. Based on the minimal binding energy and a comparative dexamethasone binding mode analysis, a list of top twenty ranked PDPs docked in the agonist conformation of hGR, with binding energies ranging between -9.8 and -11.2 kcal/mol, was obtained and analyzed for possible interactions with the human Janus kinases 1 and Interleukins-6 and SARS-CoV-2 3-chymotrypsin-like protease, Papain-like protease and RNA-dependent RNA polymerase. For each target protein, the top three ranked PDPs were selected. Eight PDPs (bregenin, hirundigenin, anhydroholantogenin, atratogenin A, atratogenin B, glaucogenin A, glaucogenin C and glaucogenin D) with high binding tendencies to the catalytic residues of multiple targets were identified. A high degree of structural stability was observed from the 100 ns molecular dynamics simulation analyses of glaucogenin C and hirundigenin complexes of hGR. The selected top-eight ranked PDPs demonstrated high druggable potentials and favourable in silico ADMET properties. Thus, the therapeutic potentials of glaucogenin C and hirundigenin can be explored for further in vitro and in vivo studies.

STAT5 as a Key Protein of Erythropoietin Signalization

Erythropoietin (EPO) acts on multiple tissues through its receptor EPOR, a member of a cytokine class I receptor superfamily with pleiotropic effects. The interaction of EPO and EPOR triggers the activation of several signaling pathways that induce erythropoiesis, including JAK2/STAT5, PI3K/AKT, and MAPK. The canonical EPOR/JAK2/STAT5 pathway is a known regulator of differentiation, proliferation, and cell survival of erythroid progenitors. In addition, its role in the protection of other cells, including cancer cells, is under intense investigation. The involvement of EPOR/JAK2/STAT5 in other processes such as mRNA splicing, cytoskeleton reorganization, and cell metabolism has been recently described. The transcriptomics, proteomics, and epigenetic studies reviewed in this article provide a detailed understanding of EPO signalization. Advances in this area of research may be useful for improving the efficacy of EPO therapy in hematologic disorders, as well as in cancer treatment.

Janus Kinase Inhibitors and Risk of Venous Thromboembolism: A Systematic Review and Meta-analysis

OBJECTIVE

To assess the risk of venous thromboembolism (VTE) in patients treated with Janus kinase (JAK) inhibitors in clinical trials.

PATIENTS AND METHODS

We performed a literature search of Ovid MEDLINE and ePub Ahead of Print, In-Process & Other Non-Indexed Citations, and Daily; Ovid EMBASE; Ovid Cochrane Central Register of Controlled Trials; Ovid Cochrane Database of Systematic Reviews; and Scopus, from inception to December 4, 2019, for randomized, placebo-controlled trials with JAK inhibitors as an intervention and reported adverse events. Odds ratio with 95% CI was calculated to estimate the VTE risk using a random effects model. Two independent reviewers screened and extracted data. The GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach was used to assess certainty in estimated VTE risk.

RESULTS

We included 29 trials (13,910 patients). No statistically significant association was found between use of JAK inhibitors and risk of VTE (odds ratio, 0.91; 95% CI, 0.57 to 1.47; P=.70; I²=0; low certainty because of serious imprecision). Results using Bayesian analysis were consistent with those of the primary analysis. Results of stratified and meta-regression analyses suggested no interaction by dose of drug, indication for treatment, or length of follow-up.

CONCLUSION

We found insufficient evidence to support an increased risk of JAK inhibitor-associated VTE based on currently available data.

Proinflammatory Features of Stem Cell-like Memory T Cells from Human Patients with Rheumatoid Arthritis

Stem cell-like memory T (Tscm) cells are a subset of memory T cells that have characteristics of stem cells. The characteristics of Tscm cells in patients with rheumatoid arthritis (RA) are not well known. The percentage of CD4⁺ and CD8⁺ Tscm cells in PBMCs and synovial fluid mononuclear cells was measured. After confirming the stem cell nature of Tscm cells, we examined their pathogenicity in RA patients and healthy controls (HCs) by assessing T cell activation markers and cytokine secretion after stimulation with anti-CD3/CD28 beads and/or IL-6. Finally, RNA transcriptome patterns in Tscm cells from RA patients were compared with those in HCs. In this study, the percentage of CD4⁺ and CD8⁺ Tscm cells in total T cells was significantly higher in RA patients than in HCs. Tscm cells self-proliferated and differentiated into memory and effector T cell subsets when stimulated. Compared with Tscm cells from HCs, Tscm cells from RA patients were more easily activated by anti-CD3/CD28 beads augmented by IL-6. Transcriptome analyses revealed that Tscm cells from RA patients showed a pattern distinct from those in HCs; RA-specific transcriptome patterns were not completely resolved in RA patients in complete clinical remission. In conclusion, Tscm cells from RA patients show a transcriptionally distinct pattern and are easily activated to produce inflammatory cytokines when stimulated by TCRs in the presence of IL-6. Tscm cells can be a continuous source of pathogenicity in RA.

Regulation of cancer stem cells in triple negative breast cancer

Triple Negative Breast Cancer (TNBC) is the most lethal subtype of breast cancer. Despite the successes of emerging targeted therapies, relapse, recurrence, and therapy failure rates in TNBC significantly outpace other subtypes of breast cancer. Mounting evidence suggests accumulation of therapy resistant Cancer Stem Cell (CSC) populations within TNBCs contributes to poor clinical outcomes. These CSCs are enriched in TNBC compared to non-TNBC breast cancers. The mechanisms underlying CSC accumulation have been well-characterized and discussed in other reviews. In this review, we focus on TNBC-specific mechanisms that allow the expansion and activity of self-renewing CSCs. We highlight cellular signaling pathways and transcription factors, specifically enriched in TNBC over non-TNBC breast cancer, contributing to stemness. We also analyze publicly available single-cell RNA-seq data from basal breast cancer tumors to highlight the potential of emerging bioinformatic approaches in identifying novel drivers of stemness in TNBC and other cancers.

Signal transducer and transcriptional activation 1 protects against pressure overload-induced cardiac hypertrophy

Signal transducers and transcriptional activation 1 (Stat1) is a member of the STATs family, and its role in various biological responses, including cell proliferation, differentiation, migration, apoptosis, and immune regulation has been extensively studied. We aimed to investigate its role in pathological cardiac hypertrophy, which is currently poorly understood. Experiments using H9C2 cardiomyocytes, Stat1, and IfngR cardiomyocyte-specific knockout mice revealed that Stat1 had a protective effect on cardiac hypertrophy. Using transverse aortic constriction (TAC)-induced cardiac hypertrophy in mice, we analyzed the degree of hypertrophy using echocardiography, pathology, and at the molecular level. Mice lacking Stat1 had more pronounced cardiac hypertrophy and fibrosis than wild-type TAC mice. Analysis of the molecular mechanisms suggested that Stat1 downregulated the mRNA levels of hypertrophy and fibrosis markers to inhibit cardiac hypertrophy, and promotes mitochondrial fission through the Ucp2/P-Drp1 pathway, enhancing mitochondrial function, and increasing compensatory myocardial ATP production in the compensatory phase for cardiac hypertrophy inhibition. Overall, this comprehensive analysis revealed that Stat1 inhibits cardiac hypertrophy by downregulating hypertrophic and fibrotic marker genes and enhancing the mitochondrial function to enhance cardiomyocyte function through the Ucp2/P-Drp1 signaling pathway.

Transcriptomic Analysis of the Effect of GAT-2 Deficiency on Differentiation of Mice Naïve T Cells Into Th1 Cells In Vitro

The neurotransmitter γ-aminobutyric acid (GABA) is known to affect the activation and function of immune cells. This study investigated the role of GABA transporter (GAT)-2 in the differentiation of type 1 helper T (Th1) cells. Naïve CD4+ T cells isolated from splenocytes of GAT-2 knockout (KO) and wild-type (WT) mice were cultured; Th1 cell differentiation was induced and transcriptome and bioinformatics analyses were carried out. We found that GAT-2 deficiency promoted the differentiation of naïve T cells into Th1 cells. RNA sequencing revealed 2984 differentially expressed genes including 1616 that were up-regulated and 1368 that were down-regulated in GAT-2 KO cells compared to WT cells, which were associated with 950 enriched Gene Ontology terms and 33 enriched Kyoto Encyclopedia of Genes and Genomes pathways. Notably, 4 signal transduction pathways (hypoxia-inducible factor [HIF]-1, Hippo, phospholipase D, and Janus kinase [JAK]/signal transducer and activator of transcription [STAT]) and one metabolic pathway (glycolysis/gluconeogenesis) were significantly enriched by GAT-2 deficiency, suggesting that these pathways mediate the effect of GABA on T cell differentiation. Our results provide evidence for the immunomodulatory function of GABA signaling in T cell-mediated immunity and can guide future studies on the etiology and management of autoimmune diseases.