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1.
Pharmacol Res ; 183: 106362, 2022 09.
Article in English | MEDLINE | ID: covidwho-1956292

ABSTRACT

The Janus kinase (JAK) family of nonreceptor protein-tyrosine kinases consists of JAK1, JAK2, JAK3, and TYK2 (Tyrosine Kinase 2). Each of these proteins contains a JAK homology pseudokinase (JH2) domain that interacts with and regulates the activity of the adjacent protein kinase domain (JH1). The Janus kinase family is regulated by numerous cytokines including interferons, interleukins, and hormones such as erythropoietin and thrombopoietin. Ligand binding to cytokine receptors leads to the activation of associated Janus kinases, which then catalyze the phosphorylation of the receptors. The SH2 domain of signal transducers and activators of transcription (STAT) binds to the cytokine receptor phosphotyrosines thereby promoting STAT phosphorylation and activation by the Janus kinases. STAT dimers are then translocated into the nucleus where they participate in the regulation and expression of dozens of proteins. JAK1/3 signaling participates in the pathogenesis of inflammatory disorders while JAK1/2 signaling contributes to the development of myeloproliferative neoplasms as well as several malignancies including leukemias and lymphomas. An activating JAK2 V617F mutation occurs in 95% of people with polycythemia vera and about 50% of cases of myelofibrosis and essential thrombocythemia. Abrocitinib, ruxolitinib, and upadacitinib are JAK inhibitors that are FDA-approved for the treatment of atopic dermatitis. Baricitinib is used for the treatment of rheumatoid arthritis and covid 19. Tofacitinib and upadacitinib are JAK antagonists that are used for the treatment of rheumatoid arthritis and ulcerative colitis. Additionally, ruxolitinib is approved for the treatment of polycythemia vera while fedratinib, pacritinib, and ruxolitinib are approved for the treatment of myelofibrosis.


Subject(s)
Arthritis, Rheumatoid , COVID-19 , Janus Kinase Inhibitors , Polycythemia Vera , Primary Myelofibrosis , Arthritis, Rheumatoid/drug therapy , Humans , Janus Kinase 1 , Janus Kinase 2/metabolism , Janus Kinase Inhibitors/pharmacology , Janus Kinase Inhibitors/therapeutic use , Janus Kinases/metabolism , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/therapeutic use
2.
Dis Model Mech ; 14(11)2021 11 01.
Article in English | MEDLINE | ID: covidwho-1430507

ABSTRACT

Vascular permeability triggered by inflammation or ischemia promotes edema, exacerbates disease progression and impairs tissue recovery. Vascular endothelial growth factor (VEGF) is a potent inducer of vascular permeability. VEGF plays an integral role in regulating vascular barrier function physiologically and in pathologies, including cancer, stroke, cardiovascular disease, retinal conditions and COVID-19-associated pulmonary edema, sepsis and acute lung injury. Understanding temporal molecular regulation of VEGF-induced vascular permeability will facilitate developing therapeutics to inhibit vascular permeability, while preserving tissue-restorative angiogenesis. Here, we demonstrate that VEGF signals through signal transducer and activator of transcription 3 (STAT3) to promote vascular permeability. We show that genetic STAT3 ablation reduces vascular permeability in STAT3-deficient endothelium of mice and VEGF-inducible zebrafish crossed with CRISPR/Cas9-generated Stat3 knockout zebrafish. Intercellular adhesion molecule 1 (ICAM-1) expression is transcriptionally regulated by STAT3, and VEGF-dependent STAT3 activation is regulated by JAK2. Pyrimethamine, an FDA-approved antimicrobial agent that inhibits STAT3-dependent transcription, substantially reduces VEGF-induced vascular permeability in zebrafish, mouse and human endothelium. Collectively, our findings suggest that VEGF/VEGFR-2/JAK2/STAT3 signaling regulates vascular barrier integrity, and inhibition of STAT3-dependent activity reduces VEGF-induced vascular permeability. This article has an associated First Person interview with the first author of the paper.


Subject(s)
Capillary Permeability , Endothelium, Vascular/metabolism , STAT3 Transcription Factor/genetics , Vascular Endothelial Growth Factor A/metabolism , Animals , CRISPR-Cas Systems , Humans , Intercellular Adhesion Molecule-1/metabolism , Janus Kinase 2/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Phosphorylation , STAT3 Transcription Factor/metabolism , Signal Transduction , Zebrafish
3.
Cell Host Microbe ; 29(8): 1277-1293.e6, 2021 Aug 11.
Article in English | MEDLINE | ID: covidwho-1293647

ABSTRACT

Immune deactivation of phagocytes is a central event in the pathogenesis of sepsis. Herein, we identify a master regulatory role of IL-6 signaling on LC3-associated phagocytosis (LAP) and reveal that uncoupling of these two processes during sepsis induces immunoparalysis in monocytes/macrophages. In particular, we demonstrate that activation of LAP by the human fungal pathogen Aspergillus fumigatus depends on ERK1/2-mediated phosphorylation of p47phox subunit of NADPH oxidase. Physiologically, autocrine IL-6/JAK2/Ninein axis orchestrates microtubule organization and dynamics regulating ERK recruitment to the phagosome and LC3+ phagosome (LAPosome) formation. In sepsis, loss of IL-6 signaling specifically abrogates microtubule-mediated trafficking of ERK, leading to defective activation of LAP and impaired killing of bacterial and fungal pathogens by monocytes/macrophages, which can be selectively restored by IL-6 supplementation. Our work uncovers a molecular pathway linking IL-6 signaling with LAP and provides insight into the mechanisms underlying immunoparalysis in sepsis.


Subject(s)
Interleukin-6/metabolism , Microtubule-Associated Proteins/metabolism , Phagocytosis/immunology , Signal Transduction , Aspergillus fumigatus/metabolism , Cytokines/metabolism , Cytoskeletal Proteins/metabolism , Humans , Janus Kinase 2/metabolism , Macrophages , Monocytes , Nuclear Proteins/metabolism , Phagocytes , Phagocytosis/physiology , Sepsis/metabolism
4.
Sci Immunol ; 6(58)2021 04 07.
Article in English | MEDLINE | ID: covidwho-1172732

ABSTRACT

Patients with coronavirus disease 2019 (COVID-19) present a wide range of acute clinical manifestations affecting the lungs, liver, kidneys and gut. Angiotensin converting enzyme (ACE) 2, the best-characterized entry receptor for the disease-causing virus SARS-CoV-2, is highly expressed in the aforementioned tissues. However, the pathways that underlie the disease are still poorly understood. Here, we unexpectedly found that the complement system was one of the intracellular pathways most highly induced by SARS-CoV-2 infection in lung epithelial cells. Infection of respiratory epithelial cells with SARS-CoV-2 generated activated complement component C3a and could be blocked by a cell-permeable inhibitor of complement factor B (CFBi), indicating the presence of an inducible cell-intrinsic C3 convertase in respiratory epithelial cells. Within cells of the bronchoalveolar lavage of patients, distinct signatures of complement activation in myeloid, lymphoid and epithelial cells tracked with disease severity. Genes induced by SARS-CoV-2 and the drugs that could normalize these genes both implicated the interferon-JAK1/2-STAT1 signaling system and NF-κB as the main drivers of their expression. Ruxolitinib, a JAK1/2 inhibitor, normalized interferon signature genes and all complement gene transcripts induced by SARS-CoV-2 in lung epithelial cell lines, but did not affect NF-κB-regulated genes. Ruxolitinib, alone or in combination with the antiviral remdesivir, inhibited C3a protein produced by infected cells. Together, we postulate that combination therapy with JAK inhibitors and drugs that normalize NF-κB-signaling could potentially have clinical application for severe COVID-19.


Subject(s)
COVID-19/metabolism , Complement Activation , Epithelial Cells/metabolism , Janus Kinase 1/metabolism , Janus Kinase 2/metabolism , Lung/metabolism , MAP Kinase Signaling System , SARS-CoV-2/metabolism , COVID-19/pathology , Cell Line, Tumor , Complement C3a/metabolism , Complement Factor B/metabolism , Epithelial Cells/pathology , Humans , Lung/pathology
5.
JAMA Dermatol ; 156(12): 1333-1343, 2020 12 01.
Article in English | MEDLINE | ID: covidwho-1008230

ABSTRACT

Importance: Baricitinib, an oral selective Janus kinase 1 and 2 inhibitor, effectively reduced disease severity in moderate to severe atopic dermatitis (AD) in 2 phase 3 monotherapy studies. Objective: To assess the efficacy and safety of 4 mg and 2 mg of baricitinib in combination with background topical corticosteroid (TCS) therapy in adults with moderate to severe AD who previously had an inadequate response to TCS therapy. Design, Setting, and Participants: This double-blind, placebo-controlled, phase 3 randomized clinical trial, BREEZE-AD7 (Study of Baricitinib [LY3009104] in Combination With Topical Corticosteroids in Adults With Moderate to Severe Atopic Dermatitis) was conducted from November 16, 2018, to August 22, 2019, at 68 centers across 10 countries in Asia, Australia, Europe, and South America. Patients 18 years or older with moderate to severe AD and an inadequate response to TCSs were included. After completing the study, patients were followed up for up to 4 weeks or enrolled in a long-term extension study. Interventions: Patients were randomly assigned (1:1:1) to receive 2 mg of baricitinib once daily (n = 109), 4 mg of baricitinib once daily (n = 111), or placebo (n = 109) for 16 weeks. The use of low-to-moderate potency TCSs was allowed. Main Outcomes and Measures: The primary end point was the proportion of patients achieving a validated Investigator Global Assessment for Atopic Dermatitis (vIGA-AD) score of 0 (clear) or 1 (almost clear), with a 2-point or greater improvement from baseline at week 16. Results: Among 329 patients (mean [SD] age, 33.8 [12.4] years; 216 [66%] male), at week 16, a vIGA-AD score of 0 (clear) or 1 (almost clear) was achieved by 34 patients (31%) receiving 4 mg of baricitinib and 26 (24%) receiving 2 mg of baricitinib compared with 16 (15%) receiving placebo (odds ratio vs placebo, 2.8 [95% CI, 1.4-5.6]; P = .004 for the 4-mg group; 1.9 [95% CI, 0.9-3.9]; P = .08 for the 2-mg group). Treatment-emergent adverse events were reported in 64 of 111 patients (58%) in the 4-mg group, 61 of 109 patients (56%) in the 2-mg group, and 41 of 108 patients (38%) in the placebo group. Serious adverse events were reported in 4 patients (4%) in the 4-mg group, 2 (2%) in the 2-mg group, and 4 (4%) in the placebo group. The most common adverse events were nasopharyngitis, upper respiratory tract infections, and folliculitis. Conclusions and Relevance: A dose of 4 mg of baricitinib in combination with background TCS therapy significantly improved the signs and symptoms of moderate to severe AD, with a safety profile consistent with previous studies of baricitinib in AD. Trial Registration: ClinicalTrials.gov Identifier: NCT03733301.


Subject(s)
Azetidines/administration & dosage , Dermatitis, Atopic/drug therapy , Glucocorticoids/administration & dosage , Purines/administration & dosage , Pyrazoles/administration & dosage , Sulfonamides/administration & dosage , Administration, Cutaneous , Administration, Oral , Adult , Azetidines/adverse effects , Dermatitis, Atopic/diagnosis , Dermatitis, Atopic/immunology , Dose-Response Relationship, Drug , Double-Blind Method , Drug Administration Schedule , Drug Therapy, Combination/adverse effects , Drug Therapy, Combination/methods , Female , Folliculitis/chemically induced , Folliculitis/epidemiology , Folliculitis/immunology , Glucocorticoids/adverse effects , Humans , Janus Kinase 1/antagonists & inhibitors , Janus Kinase 1/metabolism , Janus Kinase 2/antagonists & inhibitors , Janus Kinase 2/metabolism , Male , Middle Aged , Nasopharyngitis/chemically induced , Nasopharyngitis/epidemiology , Nasopharyngitis/immunology , Purines/adverse effects , Pyrazoles/adverse effects , Respiratory Tract Infections/chemically induced , Respiratory Tract Infections/epidemiology , Respiratory Tract Infections/immunology , Severity of Illness Index , Signal Transduction/drug effects , Signal Transduction/immunology , Sulfonamides/adverse effects , Young Adult
6.
Int Immunopharmacol ; 86: 106749, 2020 Sep.
Article in English | MEDLINE | ID: covidwho-622031

ABSTRACT

In December 2019, a novel coronavirus pneumonia (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) suddenly broke out in China and rapidly spread all over the world. Recently, a cell surface protein, known as angiotensin-converting enzyme II (ACE2), has been identified to be involved in receptor-mediated endocytosis for SARS-CoV-2 entry to the cells. Many studies have reported the clinical characteristics of COVID-19: sudden deterioration of disease around 1-2 weeks after onset; much lower level of lymphocytes, especially natural killer (NK) cells in peripheral blood; extremely high pro-inflammatory cytokines and C reactive protein (CRP). About 15.7% of patients develop severe pneumonia, and cytokine storm is an important factor leading to rapid disease progression. Currently, there are no specific drugs for COVID-19 and the cytokine storm it causes. Baricitinib intracellularly inhibits the proinflammatory signal of several cytokines by suppressing Janus kinase (JAK) JAK1/JAK2. It has been demonstrated clinical benefits for the patients with rheumatoid arthritis (RA), active systemic lupus erythematosus and atopic dermatitis with good efficacy and safety records. Baricitinib is expected to interrupt the passage and intracellular assembly of SARS-CoV-2 into the target cells mediated by ACE2 receptor, and treat cytokine storm caused by COVID-19. Several clinical trials are currently investigating the drug, and one of which has been completed with encouraging results. In this paper, we will elaborate the role of cytokine storm mediated by JAK-STAT pathway in severe COVID-19, the possible mechanisms of baricitinib on reducing the viral entry into the target cells and cytokine storm, the key points of pharmaceutical care based on the latest research reports, clinical trials progress and drug instruction from the US FDA, so as to provide reference for the treatment of severe COVID-19.


Subject(s)
Azetidines/therapeutic use , Betacoronavirus/immunology , Coronavirus Infections/drug therapy , Cytokine Release Syndrome/drug therapy , Pneumonia, Viral/drug therapy , Signal Transduction/drug effects , Sulfonamides/therapeutic use , Angiotensin-Converting Enzyme 2 , Azetidines/pharmacology , Betacoronavirus/metabolism , COVID-19 , Clinical Trials as Topic , Coronavirus Infections/complications , Coronavirus Infections/diagnosis , Coronavirus Infections/immunology , Cytokine Release Syndrome/diagnosis , Cytokine Release Syndrome/immunology , Cytokine Release Syndrome/virology , Cytokines/immunology , Cytokines/metabolism , Humans , Janus Kinase 1/antagonists & inhibitors , Janus Kinase 1/metabolism , Janus Kinase 2/antagonists & inhibitors , Janus Kinase 2/metabolism , Pandemics , Peptidyl-Dipeptidase A/metabolism , Pneumonia, Viral/complications , Pneumonia, Viral/diagnosis , Pneumonia, Viral/immunology , Purines , Pyrazoles , SARS-CoV-2 , Severity of Illness Index , Signal Transduction/immunology , Sulfonamides/pharmacology , Treatment Outcome , Virus Assembly/drug effects , Virus Internalization/drug effects
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