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Cell Oct 2022The discovery of the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway arose from investigations of how cells respond to interferons... (Review)
Review
The discovery of the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway arose from investigations of how cells respond to interferons (IFNs), revealing a paradigm in cell signaling conserved from slime molds to mammals. These discoveries revealed mechanisms underlying rapid gene expression mediated by a wide variety of extracellular polypeptides including cytokines, interleukins, and related factors. This knowledge has provided numerous insights into human disease, from immune deficiencies to cancer, and was rapidly translated to new drugs for autoimmune, allergic, and infectious diseases, including COVID-19. Despite these advances, major challenges and opportunities remain.
Topics: Animals; COVID-19; Cytokines; Humans; Interferons; Janus Kinases; Mammals; STAT Transcription Factors; Signal Transduction
PubMed: 36240739
DOI: 10.1016/j.cell.2022.09.023 -
Signal Transduction and Targeted Therapy Nov 2021The Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway was discovered more than a quarter-century ago. As a fulcrum of many vital... (Review)
Review
The Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway was discovered more than a quarter-century ago. As a fulcrum of many vital cellular processes, the JAK/STAT pathway constitutes a rapid membrane-to-nucleus signaling module and induces the expression of various critical mediators of cancer and inflammation. Growing evidence suggests that dysregulation of the JAK/STAT pathway is associated with various cancers and autoimmune diseases. In this review, we discuss the current knowledge about the composition, activation, and regulation of the JAK/STAT pathway. Moreover, we highlight the role of the JAK/STAT pathway and its inhibitors in various diseases.
Topics: Autoimmune Diseases; Humans; Janus Kinases; Neoplasm Proteins; Neoplasms; STAT Transcription Factors; Signal Transduction
PubMed: 34824210
DOI: 10.1038/s41392-021-00791-1 -
Frontiers in Immunology 2021Vitiligo is a multifactorial reversible skin disorder characterized by distinct white patches that result from melanocyte destruction. Activated CXCR3 CD8 T cells... (Review)
Review
Vitiligo is a multifactorial reversible skin disorder characterized by distinct white patches that result from melanocyte destruction. Activated CXCR3 CD8 T cells promote melanocyte detachment and apoptosis through interferon-gamma (IFN-γ secretion and chemokines secreted by keratinocytes through the Janus kinase (JAK)/signal transducer and activator of transcription (STAT)-1 signaling pathway results in further recruitment of CXCR3 CD8 T cells and the formation of a positive-feedback loop. JAK inhibitors target the JAK/STAT pathway and are now approved to treat many immune-related diseases. In the treatment of vitiligo, JAK inhibitors, including ruxolitinib, baricitinib, and tofacitinib, are effective, supporting the implication of the IFN-γ-chemokine signaling axis in the pathogenesis of vitiligo. However, more studies are required to determine the ideal dosage of JAK inhibitors for the treatment of vitiligo, and to identify other inflammatory pathways that may be implicated in the pathogenesis of this condition.
Topics: Biomarkers; Cytokines; Disease Management; Disease Susceptibility; Humans; Interferon-gamma; Janus Kinase Inhibitors; Janus Kinases; Molecular Targeted Therapy; STAT1 Transcription Factor; Signal Transduction; Treatment Outcome; Vitiligo
PubMed: 34868078
DOI: 10.3389/fimmu.2021.790125 -
Frontiers in Immunology 2022Atopic dermatitis (AD) is a chronic, inflammatory, pruritic form of dermatosis with heterogeneous manifestations that can substantially affect patients' quality of life.... (Review)
Review
Atopic dermatitis (AD) is a chronic, inflammatory, pruritic form of dermatosis with heterogeneous manifestations that can substantially affect patients' quality of life. AD has a complex pathogenesis, making treatment challenging for dermatologists. The Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway plays a central role in modulating multiple immune axes involved in the immunopathogenesis of AD. In particular, Th2 cytokines, including interleukin (IL)-4, IL-5, IL-13, IL-31, and thymic stromal lymphopoietin, which contribute to the symptoms of chronic inflammation and pruritus in AD, are mediated by JAK-STAT signal transduction. Furthermore, JAK-STAT is involved in the regulation of the epidermal barrier and the modulation of peripheral nerves related to the transduction of pruritus. Targeting the JAK-STAT pathway may attenuate these signals and show clinical efficacy through the suppression of various immune pathways associated with AD. Topical and oral JAK inhibitors with variable selectivity have emerged as promising therapeutic options for AD. Notably, topical ruxolitinib, oral upadacitinib, and oral abrocitinib were approved by the U.S. Food and Drug Administration for treating patients with AD. Accordingly, the present study reviewed the role of JAK-STAT pathways in the pathogenesis of AD and explored updated applications of JAK inhibitors in treating AD.
Topics: United States; Humans; Janus Kinases; Dermatitis, Atopic; Janus Kinase Inhibitors; Quality of Life; STAT Transcription Factors; Signal Transduction; Cytokines; Inflammation; Pruritus
PubMed: 36569854
DOI: 10.3389/fimmu.2022.1068260 -
Autoimmunity Reviews Apr 2023The four Janus kinase (JAK) proteins and the seven Signal Transducers of Activated Transcription (STAT) mediate intracellular signal transduction downstream of cytokine... (Review)
Review
The four Janus kinase (JAK) proteins and the seven Signal Transducers of Activated Transcription (STAT) mediate intracellular signal transduction downstream of cytokine receptors, which are involved in the pathology of allergic, autoimmune, and inflammatory diseases. The development of targeted small-molecule treatments with diverse selective inhibitory profiles, such as JAK inhibitors (JAKi), has supported an important change in the treatment of multiple disorders. Indeed, JAKi inhibit intracellular signalling controlled by numerous cytokines implicated in the disease process of rheumatoid arthritis and several other inflammatory and immune diseases. Therefore, JAKi have the capacity to target multiple pathways of those diseases. Other autoimmune diseases treated with JAKi include systemic sclerosis, systemic lupus erythematosus, dermatomyositis, primary Sjogren's syndrome, and vasculitis. In all of these cases, innate immunity stimulation activates adaptive immunity, resulting in the production of autoreactive T cells as well as the stimulation and differentiation of B cells. Mechanism-based treatments that target JAK-STAT pathways have the possibility of improving outcomes by reducing the consumption of glucocorticoids and/or non-specific immunosuppressive drugs in the management of systemic immune-mediated inflammatory diseases.
Topics: Humans; Janus Kinase Inhibitors; Autoimmune Diseases; Arthritis, Rheumatoid; Lupus Erythematosus, Systemic; Immunity, Innate; Janus Kinases
PubMed: 36649877
DOI: 10.1016/j.autrev.2023.103276 -
Indian Journal of Dermatology,... 2023The Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway is a key regulatory signaling system for cellular proliferation, differentiation,... (Review)
Review
The Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway is a key regulatory signaling system for cellular proliferation, differentiation, and apoptosis. In addition, JAK signaling pathway plays critical roles in orchestrating immune response through its interactions with the cytokine receptors and the transcriptions factors. Several key cytokines use JAK-STAT signaling proteins to transduce intra-cellular signals which are involved in the pathogenesis of autoimmune and inflammatory diseases such as in psoriatic disease (psoriasis, psoriatic arthritis), atopic dermatitis, alopecia areata, vitiligo, rheumatoid arthritis, ankylosing spondylitis, lupus erythematosus, Sjogren's syndrome, and other autoimmune diseases. In recent years, understandings of the molecular mechanisms of JAK-STAT pathway in the inflammatory proliferative cascades of autoimmune diseases has led to the development of JAK inhibitors and has opened a new dimension for the treatment of systemic and cutaneous inflammatory diseases. In this symposium we have provided a broad perspective on the use of Janus kinase inhibitors in cutaneous autoimmune diseases.
Topics: Humans; Janus Kinase Inhibitors; Janus Kinases; STAT Transcription Factors; Signal Transduction; Skin Diseases; Autoimmune Diseases
PubMed: 37609754
DOI: 10.25259/IJDVL_8_2023 -
Molecular Cancer Therapeutics Dec 2022The JAK/STAT axis is implicated in cancer, inflammation, and immunity. Numerous cytokines/growth factors affect JAK/STAT signaling. JAKs (JAK1, JAK2, JAK3, and TYK2)... (Review)
Review
The JAK/STAT axis is implicated in cancer, inflammation, and immunity. Numerous cytokines/growth factors affect JAK/STAT signaling. JAKs (JAK1, JAK2, JAK3, and TYK2) noncovalently associate with cytokine receptors, mediate receptor tyrosine phosphorylation, and recruit ≥1 STAT proteins (STAT1, STAT2, STAT3, STAT4, STAT5a, STAT5b, and STAT6). Tyrosine-phosphorylated STATs dimerize and are then transported into the nucleus to function as transcription factors. Signaling is attenuated by specific suppressor of cytokine signaling proteins, creating a negative feedback loop. Both germline mutations and polymorphisms of JAK family members correlate with specific diseases: Systemic lupus erythematosus (TYK2 polymorphisms); severe combined immunodeficiency (JAK3 mutations); pediatric acute lymphoblastic leukemia (TYK2 mutations); and hereditary thrombocytosis (JAK2 mutations). Somatic gain-of-function JAK mutations mainly occur in hematologic malignancies, with the activating JAK2 V617F being a myeloproliferative disorder hallmark; it is also seen in clonal hematopoiesis of indeterminate potential. Several T-cell malignancies, as well as B-cell acute lymphoblastic leukemia, and acute megakaryoblastic leukemia also harbor JAK family somatic alterations. On the other hand, JAK2 copy-number loss is associated with immune checkpoint inhibitor resistance. JAK inhibitors (jakinibs) have been deployed in many conditions with JAK activation; they are approved in myeloproliferative disorders, rheumatoid and psoriatic arthritis, atopic dermatitis, ulcerative colitis, graft-versus-host disease, alopecia areata, ankylosing spondylitis, and in patients hospitalized for COVID-19. Clinical trials are investigating jakinibs in multiple other autoimmune/inflammatory conditions. Furthermore, dermatologic and neurologic improvements have been observed in children with Aicardi-Goutieres syndrome (a genetic interferonopathy) treated with JAK inhibitors.
Topics: Humans; COVID-19; Janus Kinase 1; Janus Kinase 2; Janus Kinase Inhibitors; Janus Kinases; Phosphorylation; Precursor Cell Lymphoblastic Leukemia-Lymphoma; STAT Transcription Factors; Tyrosine
PubMed: 36252553
DOI: 10.1158/1535-7163.MCT-22-0323 -
Skin Therapy Letter Jan 2022Janus kinase inhibitors, also commonly referred to as JAK inhibitors, are a novel drug class that target and block cytokine signaling mediated by the Janus kinase-signal... (Review)
Review
Janus kinase inhibitors, also commonly referred to as JAK inhibitors, are a novel drug class that target and block cytokine signaling mediated by the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway, thereby regulating immune response and cell growth. Although JAK inhibitors are mainly used for rheumatological conditions such as rheumatoid arthritis, their application in the field of dermatology is actively being investigated. Tofacitinib is US FDA-approved for psoriatic arthritis and showing promise for treating psoriasis. Most recently, regulatory approvals for the US were gained by ruxolitinib as a first-inclass, selective, topical therapy for atopic dermatitis and oral upadacitinib for active psoriatic psoriasis. Additionally, abrocitinib and upadacitinib have demonstrated efficacy in atopic dermatitis and are pending FDA approval for this indication. The therapeutic potential of JAK inhibitors in dermatological conditions such as alopecia areata, psoriasis, atopic dermatitis, vitiligo, and dermatomyositis are showing promising results in clinical trials. Adverse events for JAK inhibitors seem to be similar to that of biologic drugs. Common adverse effects include increased risk of infections and thromboembolic events. Further investigation is needed to not only better understand the safety profile of JAK inhibitors, but also their full utility within the field of dermatology.
Topics: Alopecia Areata; Dermatology; Humans; Janus Kinase Inhibitors; Janus Kinases; Vitiligo
PubMed: 35081305
DOI: No ID Found -
Signal Transduction and Targeted Therapy Jul 2021Cancer development and its response to therapy are regulated by inflammation, which either promotes or suppresses tumor progression, potentially displaying opposing...
Cancer development and its response to therapy are regulated by inflammation, which either promotes or suppresses tumor progression, potentially displaying opposing effects on therapeutic outcomes. Chronic inflammation facilitates tumor progression and treatment resistance, whereas induction of acute inflammatory reactions often stimulates the maturation of dendritic cells (DCs) and antigen presentation, leading to anti-tumor immune responses. In addition, multiple signaling pathways, such as nuclear factor kappa B (NF-kB), Janus kinase/signal transducers and activators of transcription (JAK-STAT), toll-like receptor (TLR) pathways, cGAS/STING, and mitogen-activated protein kinase (MAPK); inflammatory factors, including cytokines (e.g., interleukin (IL), interferon (IFN), and tumor necrosis factor (TNF)-α), chemokines (e.g., C-C motif chemokine ligands (CCLs) and C-X-C motif chemokine ligands (CXCLs)), growth factors (e.g., vascular endothelial growth factor (VEGF), transforming growth factor (TGF)-β), and inflammasome; as well as inflammatory metabolites including prostaglandins, leukotrienes, thromboxane, and specialized proresolving mediators (SPM), have been identified as pivotal regulators of the initiation and resolution of inflammation. Nowadays, local irradiation, recombinant cytokines, neutralizing antibodies, small-molecule inhibitors, DC vaccines, oncolytic viruses, TLR agonists, and SPM have been developed to specifically modulate inflammation in cancer therapy, with some of these factors already undergoing clinical trials. Herein, we discuss the initiation and resolution of inflammation, the crosstalk between tumor development and inflammatory processes. We also highlight potential targets for harnessing inflammation in the treatment of cancer.
Topics: Antigen Presentation; Dendritic Cells; Humans; Immunity, Cellular; Inflammasomes; Inflammation; Interferons; Interleukins; Janus Kinases; Mitogen-Activated Protein Kinase Kinases; Molecular Targeted Therapy; NF-kappa B; Neoplasms; STAT Transcription Factors; Signal Transduction; Toll-Like Receptors; Transforming Growth Factor beta
PubMed: 34248142
DOI: 10.1038/s41392-021-00658-5 -
Drugs Jun 2023Alopecia areata (AA) is a relapsing, chronic, immune-mediated disease characterized by nonscarring, inflammatory hair loss that can affect any hair-bearing site. AA... (Review)
Review
Alopecia areata (AA) is a relapsing, chronic, immune-mediated disease characterized by nonscarring, inflammatory hair loss that can affect any hair-bearing site. AA clinical presentation is heterogeneous. Its pathogenesis involves immune and genetic factors and several pro-inflammatory cytokines involved in AA pathogenesis, including interleukin-15 and interferon-γ, as well as Th2 cytokines, such as IL-4/IL-13, that signal through Janus kinase (JAK) pathway. AA treatment aims to stop its progression and reverse hair loss, and JAK inhibition has been shown to stop hair loss and reverse alopecia and has exhibited promising results in treating AA in clinical trials. Baricitinib, an oral, reversible, selective JAK1/JAK2 inhibitor, was shown to be superior to placebo on hair growth after 36 weeks of treatment in adults with severe AA in a phase 2 trial and recently in two phase 3 trials (BRAVE-AA1 and BRAVE-AA2). In both studies, the most common adverse events were upper respiratory tract infections, urinary tract infection, acne, headache, and elevated creatine kinase levels. On the basis of these trial results, baricitinib was recently approved by the European Medicines Agency (EMA) and US Food and Drug Administration (FDA) for the treatment of adults with severe AA. Nevertheless, longer trials are needed to determine the long-term efficacy and safety of baricitinib in AA. Current trials are ongoing and are planned to remain randomized and blinded for up to 200 weeks.
Topics: Adult; Humans; Alopecia Areata; Alopecia; Hair; Janus Kinase Inhibitors; Janus Kinases; Cytokines
PubMed: 37195491
DOI: 10.1007/s40265-023-01873-w