Janus kinases in immune cell signaling

Molecular characterization, expression, evolutionary analysis and molecular docking of the Janus activated kinase family members of largemouth bass (Micropterus salmoides)

Janus kinases (JAKs) play crucial roles in the immune responses by binding the cytokine receptors. In the present study, five JAKs family members (JAK1, JAK2a, JAK2b, JAK3, and TYK2) were identified in largemouth bass (Micropterus salmoides). The five JAKs members of largemouth bass contained several conserved protein domains, including a FERM domain, an SH2 domain, a pseudokinase (STyrkc) domain, and a tyrosine kinase (Tyrkc) domain. Phylogenetic analysis revealed the JAK2/2a/2b and JAK3 formed a clade and the JAK1/TYK2 formed another separate clade. Realtime qPCR detection showed that all five JAKs genes were constitutively expressed in ten selected tissues, with highly expression in spleen and head kidney (HK). Following Edwardsiella piscicida infection, the five JAKs genes were significantly upregulated in the spleen and primary hepatocytes at different times post infection. Further selection pressure analysis revealed the five JAKs members underwent negative selection pressures during evolution. The FERM and Tyrkc domains of the five JAK members occurred purifying selection, and involved in interaction with STAT3, which confirmed by protein-protein interaction (PPI) network and molecular docking analysis. Also, molecular docking results indicated that the hydrogens bonds and salt bonds had crucial roles in the JAK/STAT3 complexes formation. Our results indicated that JAKs had important roles in the immune response against bacterial in largemouth bass, providing basis for elucidating the mechanism of JAK/STAT signaling pathway in fish.

Activity Regulation and Conformation Response of Janus Kinase 3 Mediated by Phosphorylation: Exploration from Correlation Network Analysis and Markov Model

The activity of the enzyme JAK3 is modulated by tyrosine phosphorylation, yet the underlying molecular details remain not fully understood. In this study, we employed a GaMD trajectory-based Markov model and correlation network analysis (CNA) to investigate the impact of single phosphorylation (SP) at Y980 (pY980) and double phosphorylation (DP) at Y980/Y981 (pY980/pY981) on the conformational dynamics of JAK3 bound by inhibitors IZA and MI1. The Markov model analysis indicated that both SP and DP result in fewer conformational states and significantly influence the conformational dynamics of the P-loop, αC-helix, and loop1-loop3, while maintaining the hinge region's high rigidity. The CNA findings revealed that phosphorylation alters the communication network among different structural regions of JAK3, providing a rational explanation for how phosphorylation affects the conformational dynamics of the distant P-loop and loop1-loop3. Moreover, the conformational changes mediated by SP and DP further affect the interactions between the inhibitors and the hot spots (L828, V836, E903, Y904, L905, and L956) of JAK3. This work offers valuable theoretical insights into the molecular mechanisms that regulate JAK3 activity.

Novel janus kinase 3 inhibitor ritlecitinib suppresses T and B cell responses to prevent acute cardiac allograft rejection in mice

Acute rejection is the main contributor to early allograft failure. Current immunosuppressive regimens have shortcomings, such as toxicity and minimal inhibitory effects on B cells. Hence, developing novel, effective, and selective anti-acute rejection drugs is crucial. Therefore, this study aimed to investigate the inhibitory effect of ritlecitinib (PF-06651600), a new janus kinase 3 inhibitor, on T and B cells, as well its preventive effects on acute allograft rejection. A murine cardiac transplantation model coupled with cell culture- and immunohistochemistry-based techniques was used. In vitro assays demonstrated that ritlecitinib inhibits naïve CD4+ T cell differentiation into T helper (Th)1 and Th17 cells, reduces relative inflammatory cytokines, and suppresses CD4+ and CD8+ T cell proliferation. Furthermore, ritlecitinib inhibited B cell activation and differentiation and antibody production. In vivo experiments revealed that ritlecitinib significantly prolongs allograft survival, decreases serum donor-specific antibody immunoglobulin G levels, alleviats allograft damage, and reduces C4d deposition and T, B, and plasma cell infiltration in allografts. Moreover, B and plasma cell percentages and counts were significantly decreased in recipient spleen, lymph nodes, bone marrow, and blood. Overall, ritlecitinib prevented acute rejection in cardiac transplantation by inhibiting T and B cells, suggesting its potential as a novel clinical immunosuppressant.

An In Silico Approach to Uncover Selective JAK1 Inhibitors for Breast Cancer from Life Chemicals Database

JAK1, a key regulator of multiple oncogenic pathways, is a sought-out target, and its expression in immune cells and tumour-infiltrating lymphocytes (TILs) is associated with a favorable prognosis in breast cancer. JAK1 activates IL-6 via ERBB2 receptor tyrosine kinase signalling and promotes metastatic cancer and STAT3 activation in breast cancer cells. Hence, targeting JAK1 in breast cancer is being explored as a potential therapeutic strategy. A comprehensive in silico approach was utilised in this study to identify selective JAK1 inhibitors from the Life chemicals database. First, we utilised an anticancer focussed library and performed molecular docking to screen against JAK1 protein. The top 10 compounds from docking were taken for cross-docking, to assess the selectivity towards JAK1 target. Lipinski's RO5 was checked for eliminating the compounds that violate rules. Toxicity, biological activity and reactivity for the identified best compounds were predicted by Protox-II server, PASS server and cDFT analysis respectively. MD simulations were carried out to examine the stability and dynamic behaviour of the top leads, including the long-term stability of the ligand-receptor complex and any conformational changes. Lastly, the MM/PBSA method was used to determine the binding free energy of the protein-ligand complex. Our in silico approach has yielded a promising set of compounds F2638-0133, F3408-0020 and F5833-7435 with the potential to selectively target JAK1, a critical player in breast cancer progression. The docking, simulation and MM/PBSA results were compared with standard drug abrocitinib. Identified compounds exhibit favorable binding interactions, electronic properties and robust stability profiles compared to standard drug, making them promising leads for further experimental validation.

Identification of novel covalent JAK3 inhibitors through consensus scoring virtual screening: integration of common feature pharmacophore and covalent docking

Accumulated research strongly indicates that Janus kinase 3 (JAK3) is intricately involved in the initiation and advancement of a diverse range of human diseases, underscoring JAK3 as a promising target for therapeutic intervention. However, JAK3 shows significant homology with other JAK family isoforms, posing substantial challenges in the development of JAK3 inhibitors. To address these limitations, one strategy is to design selective covalent JAK3 inhibitors. Therefore, this study introduces a virtual screening approach that combines common feature pharmacophore modeling, covalent docking, and consensus scoring to identify novel inhibitors for JAK3. First, common feature pharmacophore models were constructed based on a selection of representative covalent JAK3 inhibitors. The optimal qualitative pharmacophore model proved highly effective in distinguishing active and inactive compounds. Second, 14 crystal structures of the JAK3-covalent inhibitor complex were chosen for the covalent docking studies. Following validation of the screening performance, 5TTU was identified as the most suitable candidate for screening potential JAK3 inhibitors due to its higher predictive accuracy. Finally, a virtual screening protocol based on consensus scoring was conducted, integrating pharmacophore mapping and covalent docking. This approach resulted in the discovery of multiple compounds with notable potential as effective JAK3 inhibitors. We hope that the developed virtual screening strategy will provide valuable guidance in the discovery of novel covalent JAK3 inhibitors.

First-in-human study of CPL'116 - a dual JAK/ROCK inhibitor - in healthy subjects

Background

CPL'116 is a novel Janus kinase (JAK) and Rho-associated coiled-coil containing protein kinase (ROCK) dual inhibitor and a promising drug candidate for the treatment of inflammatory and fibrotic diseases. We conducted this first-in-human, Phase I clinical trial to evaluate the safety, pharmacokinetics (PK), and exploratory pharmacodynamics (PD) of CPL'116 in healthy subjects.

Methods

Phase I clinical trial in healthy White volunteers was conducted after single (n = 21, 10-300 mg) and multiple (n = 32, 30-240 mg or placebo, 14-day b.i.d.) administrations of CPL'116 including a food effect study (n = 12, 120 mg). The multiple ascending dose part was double-blinded and placebo-controlled. The primary endpoint was safety evaluation, and the secondary endpoint was PK. Exploratory PD was studied by measuring the inhibition of JAK and ROCK in the blood by assessing STAT1, STAT5, and MLC phosphorylation.

Results

Safety parameters were comparable between the placebo and active treatment groups, with no clinically meaningful variations in the safety parameters between the cohorts. No deaths or serious adverse events (SAEs) were reported. No influence on hematological parameters (neutrophil count, red cell distribution width, and mean corpuscular volume) was observed. Plasma Cmax and AUC increased proportionally in the dosing range of 60-240 mg. Median tmax ranged 2-3 h. Food increased the absorption of CPL'116. Compared to placebo, CPL'116 at 240 mg dose showed a decrease in the phosphorylation of STAT1 (Days 1 and 14, p < 0.05) and STAT5 (Day 14, p < 0.05). A decrease in MLC phosphorylation indicated a potential trend at p < 0.1.

Conclusion

CPL'116 was safe and well-tolerated by healthy subjects. The PK profile is well suited for twice-daily administration and justifies further clinical development. Exploratory PD studies indicated the ability of CPL'116 to affect the JAK and ROCK pathways in humans, hinting at its potential therapeutic role in diseases benefiting from its dual mode of action. The positive results of this study indicate the possibility of developing a novel class of therapeutics that address both inflammatory and fibrotic processes.

Clinical Trial RegistrationMethods

clinicaltrials.gov, identifier NCT04670757.

Disease-modifying strategies: Targeting protein kinases in multiple sclerosis and other autoimmune disorders

A wide variety of immunomodulatory therapies are already available for the treatment of multiple sclerosis (MS). Through fundamental insights from basic research with a gain of knowledge in the pathological processes underlying MS, the exploration of additional medical compounds within clinical trials has been ignited. Emerging novel medications with innovative mechanisms of action are being introduced. Those mechanisms of action include a broad therapeutic spectrum of substances targeting various protein kinases, some of which could also be used for the treatment of other autoimmune-mediated diseases. The advancement of new compounds could therefore enable a more personalized approach in treating MS, taking into consideration patients' co-existing autoimmune-mediated diseases. In this review, we discuss potential compounds targeting protein kinases, currently under investigation in clinical trials for various autoimmune diseases that could become viable treatment options for MS and comorbid autoimmune conditions in the future.

Macrophage-derived CCL1 targets CCR8 receptor in hepatic stellate cells to promote liver fibrosis through JAk/STAT pathway

Liver fibrosis is caused by liver injury resulting from the wound healing response. According to recent research, the primary factor responsible for liver fibrosis is the activation of hepatic stellate cells (HSCs). C-C motif chemokine ligand 1 (CCL1) is one of several chemokine genes clustered on chromosome 17, which is involved in immune regulation and inflammatory processes. However, the role of CCL1 in liver fibrosis has not been reported. We found that CCL1 secreted by macrophages can target and activate the receptor protein C-C motif chemokine receptor 8 (CCR8) of HSCs, accelerating liver fibrosis progression by activating the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signalling pathway. This suggested that the CCL1-mediated regulation of CCR8 is an important event in liver fibrosis progression. In conclusion, this study identified a novel signalling axis, the CCL1/CCR8/JAK/STAT pathway, which regulates the activation and apoptosis of HSCs, thus providing a novel therapeutic strategy for liver fibrosis.

The Expanding Therapeutic Potential of Deucravacitinib Beyond Psoriasis: A Narrative Review

Deucravacitinib is an allosteric, selective tyrosine kinase 2 (TYK2) inhibitor that has demonstrated significant efficacy in the treatment of psoriasis. TYK2, a member of the Janus kinase (JAK) family, plays a critical role in intracellular signaling pathways for pro-inflammatory cytokines. Unlike traditional JAK inhibitors, which target active domains, deucravacitinib selectively binds to the pseudokinase domain of TYK2. This binding induces a conformational change that locks the enzyme in an inactive state, ensuring superior selectivity for TYK2 over JAK 1/2/3. This unique mechanism specifically inhibits key pro-inflammatory cytokines, including IL-12, IL-23, and type I interferons, critical in the pathogenesis of psoriasis and other immune-mediated diseases. As a result, deucravacitinib represents a promising option for targeted therapy in immune-mediated diseases and may reduce adverse events commonly associated with broader immunosuppressive treatments. Furthermore, its oral administration offers a convenient alternative to injectable biologics, potentially improving patient adherence and treatment satisfaction. This review highlights recent studies suggesting that deucravacitinib may also have therapeutic benefits in psoriatic arthritis, palmoplantar pustulosis, systemic lupus erythematosus, Sjogren's disease, and inflammatory bowel disease. Given its expanding therapeutic potential, deucravacitinib may provide a safer and more effective alternative to current therapies, offering a tailored approach to treatment.

JAK inhibition and axial spondyloarthritis: new steps on the path to understanding pathophysiology

Axial spondyloarthritis (axSpA) is a chronic inflammatory disease that predominantly affects the sacroiliac joints and spine. Tumor necrosis factor (TNF) and interleukin (IL)-17A are key cytokines in disease pathogenesis and are established axSpA treatment targets. Recently, axSpA treatment options have been complemented by Janus kinase inhibitors (JAKi), which inhibit various cytokines without directly impacting TNF or IL-17 signaling. The effect of JAKi on axSpA remains under investigation: besides a JAK2-mediated (and potentially tyrosine kinase 2 [TYK2]-mediated) effect on the IL-23/IL-17 axis, emerging evidence suggests γδ T cells, type 3 innate lymphoid cells, and mucosa-associated invariant T cells, which are dependent on IL-7 and/or IL-15 and thus on JAK1, are strongly inhibited by JAKi used to treat axSpA. This review summarizes potential effects of JAKi on axSpA and shows evidence from pre-clinical/clinical studies. Greater understanding of the mechanisms of action of available treatments may improve knowledge of axSpA and pave the road for future therapies.

Cytokines in age-related eye diseases: pathogenesis and potential targets for innovative therapies

Age-related eye diseases (AREDs), such as dry eye disease (DED), age-related macular degeneration (AMD), glaucoma, and diabetic retinopathy (DR), are significant worldwide health concerns due to their rising prevalence and debilitating effects. Despite substantial research on the pathobiology of AREDs, the impact of immune-related alterations caused by aging is still not well understood. Tissue-resident cells and invading immune cells in the eye control innate responses in the event of damage or infection. However, as cells age, they gradually lose their ability to perform their protective duties and develop abnormal characteristics. Therefore, the disrupted regulation of immune responses in the eyes of older individuals enhances their vulnerability to and the intensity of eye disorders. Cytokines, immune system components, have a role in developing AREDs by contributing to inflammation. This paper examines the deficiencies in the pathogenic and therapeutic aspects of pro-inflammatory cytokines in AREDs that require further investigation in future studies.

Mechanistic paradigms of immunotoxicity, triggered by nanoparticles - a review

Nanoparticles (NPs) possess the ability to penetrate cells and elicit a rapid and targeted immune response, influenced by their distinct physicochemical properties. These particles can engage with both micro and macromolecules, thereby impacting various downstream signaling pathways that may lead to cell death. This review provides a comprehensive overview of the primary mechanisms contributing to the immunotoxicity of both organic and inorganic nanoparticles. The effects of carbon-based nanomaterials (CNMs), including single-walled carbon nanotubes, multi-walled carbon nanotubes, graphene, and metal oxide nanoparticles, on various immune cell types such as macrophages, neutrophils, monocytes, dendritic cells (DCs), antigen-presenting cells (APCs), and RAW 264.7 cells are examined. The immune responses discussed encompass inflammation, oxidative stress, autophagy, and apoptosis. Additionally, the roles of pro-inflammatory cytokines such as IL-1β, IL-6, TNF-α, and IFN-γ, along with JAK/STAT signaling pathways, are highlighted. The interaction of NPs with oxidative stress pathways, including MAPK signaling and Nrf2/ARE signaling, is also explored. Furthermore, the mechanisms by which nanoparticles induce damage to organelles such as lysosomes, the endoplasmic reticulum, exosomes, and Golgi bodies within the immune system are addressed. The review also emphasizes the genotoxic and epigenetic mechanisms associated with the immunotoxicity of NPs. Recent advancements regarding the immunotherapeutic potential of engineered NPs are reported. The roles of autophagy and apoptosis in the immunotoxicity of NPs merit further investigation. In conclusion, understanding how engineered nanoparticles modulate immune responses may facilitate the prevention and treatment of human diseases, including cancer and autoimmune disorders.

Sometimes Small Is Beautiful: Discovery of the Janus Kinases (JAK) and Signal Transducer and Activator of Transcription (STAT) Pathways and the Initial Development of JAK Inhibitors for IBD Treatment

The Janus kinase/signal transducer and activator of transfection (JAK/STAT) system is comprised of multiple cell surface receptors, receptor tyrosine kinases, and signal transducers that are key components of numerous systems involved in malignancy, inflammation, immune surveillance and development, cellular proliferation, metabolism, differentiation, apoptosis, and hematologic disorders, all of which when disrupted can produce severe disease. Nevertheless, small molecule inhibitors of the four known JAKs, termed JAKinibs, have found therapeutic indications for a broad category of diseases. In this perspective, I will summarize the development of JAK inhibitors, whose origins were in antiquity, with particular attention to their use in treating patients with inflammatory bowel disease (IBD). This perspective is accompanied by a companion publication addressing how JAKinibs have forever altered the landscape of IBD therapy.

Direct reprogramming of human fibroblasts into hair-inducing dermal papilla cell-like cells by a single small molecule

Dermal papilla cells (DPCs) are a crucial subset of mesenchymal cells in the skin responsible for regulating hair follicle development and growth, making them invaluable for cell-based therapies targeting hair loss. However, obtaining sufficient DPCs with potent hair-inducing abilities remains a persistent challenge. In this study, the Food and Drug Administration (FDA)-approved drug library was utilized to screen small molecules capable of reprogramming readily accessible human skin fibroblasts into functional DPCs. In the initial screening, five candidate small molecules were identified from a pool of 1,817 compounds, and the small molecule peficitinib was further identified by the further hair follicle regeneration experiments. Following peficitinib treatment, fibroblasts derived from primary human foreskin and scalp exhibited the capability to induce hair growth and possessed a molecular profile highly similar to that of primary DPCs. We refer to these cells as dermal papilla cell-like cells (DPC-LCs). Furthermore, transcriptome analysis showed that the wingless/integrated (Wnt) signaling pathway and the transforming growth factor β (TGF-β) signaling pathway, both of which play crucial roles in hair follicle morphogenesis, are upregulated and enriched in these DPC-LCs. These functional DPC-LCs offer a promising avenue for obtaining a plentiful supply of hair-inducing cells, thereby advancing the development of therapeutic strategies for hair loss treatment.

Dibenzo [a, c] phenazin-11-yl(phenyl) methanone (SBLJ23), a novel selective inhibitor targeting JAK2V617F mutation in myeloproliferative neoplasms

Background

The JAK2V617F mutation plays a crucial part in the pathogenesis of myeloproliferative neoplasms (MPN), which includes polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF) leading to aberrant proliferation and survival of hematopoietic cells. Alongside the challenges of drug resistance and side effects, identifying novel compounds that selectively target JAK2V617F could provide more effective and safer therapeutic options for patients with MPNs.

Materials and Methods

We employed computational approaches like high-throughput virtual screening, molecular dynamics simulations (MDS), and binding free energy calculations to identify inhibitors targeting wild and mutant JAK2 kinases. JAK2V617F positive HEL, wild type JAK2 positive TF-1, and non-cancerous Vero cells were used for in vitro validations.

Results

SBLJ23 emerged as a top candidate inhibitor with specificity for JAK2V617F. Protein-ligand interaction studies and MDS revealed stable interactions and binding of SBLJ23 over the simulation period, with Root Mean Square Deviation (RMSD) indicating consistent binding after 1t15ns. SBLJ23 displayed a half maximal inhibitory concentration (IC50) value of 522.4 nM against the JAK2 enzyme. The compound exhibited inhibition of cell proliferation in HEL and TF-1 cells, with half maximal cell growth inhibitory concentration (GI50) values of 2.51 and 15.87 µM, respectively. Moreover, SBLJ23 induced G2/M cell cycle arrest in HEL cells to facilitate apoptosis in these cell lines. The compound significantly reduced the percentage of phospho JAK2 and phospho STAT3 in HEL cells.

Conclusion

High binding affinity, stable interaction profile, favorable binding free energy, and in vitro validations claim SBLJ23 as a potential lead compound against JAK2V617F and suggest further development and optimization towards clinical application in managing myeloproliferative neoplasms.

Identification of Subtypes and Diagnostic Markers Related to Necroptosis in Sepsis

Sepsis is a serious systemic infection with a high mortality rate. More and more evidence suggested that necroptosis plays a crucial role in the pathogenesis and progression of sepsis. This study aimed to elucidate the biological function and clinical significance of necroptosis in sepsis, and identify new potential biomarkers to improve the diagnosis and treatment of sepsis. Firstly, we identified 40 differentially expressed necroptosis related genes (DENRGs). Subsequently, a protein interaction (PPI) network of 40 DENRGs was constructed. Based on the key NRGs in the PPI network, the LASSO algorithm was used to screen eight diagnostic-related NRGs in sepsis, and a diagnostic model and risk score were constructed. The ROC analysis results indicated that the eight NRGs diagnostic model has good diagnostic performance (AUC = 0.955). There is a significant difference in risks core between normal samples and sepsis patients. The results of immune infiltration analysis showed that eight diagnostic-related NRGs were significantly correlated with multiple immune cells. Given the clinical significance of necroptosis in sepsis, we identified two molecular subtypes of sepsis based on eight NRGs. The necroptosis score of subtype 1 is significantly lower than that of subtype 2, while the immune score of subtype 1 is significantly higher than that of subtype 2. In summary, we developed and validated a diagnostic model and risk score based on eight NRGs, and identified two completely different subtypes associated with sepsis. Our research may provide new insights into the mechanisms of necroptosis in sepsis and the identification of potential biomarkers.

Tofacitinib in focus: Fascinating voyage from conventional formulations to novel delivery systems

Tofacitinib, a Janus kinase (JAK) inhibitor, has emerged as a primary therapeutic agent for managing autoimmune diseases such as rheumatoid arthritis, psoriatic arthritis, dermatitis and ulcerative colitis. By inhibiting the phosphorylation of JAK enzymes, tofacitinib prevents their activation within the JAK-STAT signaling pathway, which is vital for inflammatory responses. However, the tofacitinib delivery presents significant challenges, including pH-dependent solubility, poor permeability and susceptibility to oral degradation. This review provides an in-depth analysis of current and emerging formulations to enhance the delivery and efficiency of tofacitinib. This review highlights the physicochemical, pharmacodynamic and pharmacokinetic properties of tofacitinib. Additionally, it discusses various strategies, including oral modified release formulations, topical/transdermal delivery utilizing lipid-based and polymeric systems, and parenteral delivery systems. Recent advancements in nanotechnology, such as liposomes, micelles, keratinocyte exosomes, proposomes, proglycosomes, transethosomes, squalenyl nanoparticles and lyotropic liquid crystalline nanoparticles, are explored as potential nanocarriers to existing delivery constraints. The development of advanced tofacitinib delivery systems can address the challenges in its delivery and improve therapeutic outcomes and patient compliance, paving the way for enhanced treatment strategies in autoimmune and inflammatory conditions.

Progressing advanced therapies for inflammatory bowel disease: Current status including dual biologic therapy and discontinuation of biologics

INTRODUCTION

Advanced therapies (ADT) that encompass biological agents and small molecules have been approved for the treatment of inflammatory bowel disease (IBD), broadening the spectrum of available treatment options. Nevertheless, a substantial proportion of patients fail to achieve satisfactory responses, necessitating surgical intervention. Treatment objectives have evolved beyond clinical remission, reduction of inflammation, and mucosal healing, shifting focus toward enhancing the quality of life, acknowledging the profound impact of IBD on physical and mental well-being.

AREA COVERED

This comprehensive review describes the current landscape of ADT for IBD, including dual biologic therapy (DBT), which involves the combination of two biologics or a single biologic with a small-molecule compound, as well as considerations surrounding the discontinuation of biologics.

EXPERT OPINION

ADT is the standard treatment for moderate to severe IBD, while DBT appears promising for specific subsets of patients, including those with refractory disease or extraintestinal manifestations. However, these approaches may increase the risk of adverse effects, including malignancy. To optimize individualized treatment strategies in patients with refractory IBD, further trials are needed to refine ADT's predictive value, establish DBT's safety and indications, define biologic discontinuation criteria, and evaluate emerging biomarkers, artificial intelligence, and bowel ultrasound in patient management.

Efficacy and safety of Janus kinase inhibitors in patients with difficult-to-treat rheumatoid arthritis

OBJECTIVES

This study evaluated the effectiveness of Janus kinase inhibitors (JAKi) in patients with difficult-to-treat rheumatoid arthritis (D2T RA).

METHODS

This study included 220 patients with RA who were treated with JAKi. Sixty-two patients were naïve to biological disease-modifying antirheumatic drugs (bDMARDs)/JAKi (1st group), 57 patients were failure to one bDMARDs/JAKi (2nd group), and 101 patients were failure to ≥ 2 bDMARDs/JAKi. Of these 101 patients, 25 did not meet the D2T RA criteria (non-D2T RA group) and 76 met the D2T RA criteria (D2T RA group).

RESULTS

: DAS28-ESR was improved in all groups at 24 weeks (1st: P < .01, 2nd: P < .01, non-D2T RA: P = .01, D2TRA: P = .02), and improvement ratio of DAS28-ESR was not different between DT2RA group and 2nd (P = .73) or non-D2T RA group (P = .68). Glucocorticoid use [odds ratios: 8.67; 95% confidence interval (CI): 1.23-60.90; P = .03] and number of past bDMARD/JAKi uses ≥ 3 (odds ratios: 10.55; 95% CI: 1.39-80.30; P = .02) were risk factors for DAS28-ESR ≥ 3.2 at 24 weeks in the D2T RA group.

CONCLUSIONS

Clinical efficacy of JAKi in D2T RA group did not differ from that in 2nd and non-D2T RA groups. Glucocorticoid use and multiple bDMARD/JAKi failure were poor prognostic factors for D2T RA.

QSAR-driven screening uncovers and designs novel pyrimidine-4,6-diamine derivatives as potent JAK3 inhibitors

This study presents a robust and integrated methodology that harnesses a range of computational techniques to facilitate the design and prediction of new inhibitors targeting the JAK3/STAT pathway. This methodology encompasses several strategies, including QSAR analysis, pharmacophore modeling, ADMET prediction, covalent docking, molecular dynamics (MD) simulations, and the calculation of binding free energies (MM/GBSA). An efficacious QSAR model was meticulously crafted through the employment of multiple linear regression (MLR). The initial MLR model underwent further refinement employing an artificial neural network (ANN) methodology aimed at minimizing predictive errors. Notably, both MLR and ANN exhibited commendable performance, showcasing R2 values of 0.89 and 0.95, respectively. The model's precision was assessed via leave-one-out cross-validation (CV) yielding a Q2 value of 0.65, supplemented by rigorous Y-randomization. , The pharmacophore model effectively differentiated between active and inactive drugs, identifying potential JAK3 inhibitors, and demonstrated validity with an ROC value of 0.86. The newly discovered and designed inhibitors exhibited high inhibitory potency, ranging from 6 to 8, as accurately predicted by the QSAR models. Comparative analysis with FDA-approved Tofacitinib revealed that the new compounds exhibited promising ADMET properties and strong covalent docking (CovDock) interactions. The stability of the new discovered and designed inhibitors within the JAK3 binding site was confirmed through 500 ns MD simulations, while MM/GBSA calculations supported their binding affinity. Additionally, a retrosynthetic study was conducted to facilitate the synthesis of these potential JAK3/STAT inhibitors. The overall integrated approach demonstrates the feasibility of designing novel JAK3/STAT inhibitors with robust efficacy and excellent ADMET characteristics that surpass Tofacitinib by a significant margin.Communicated by Ramaswamy H. Sarma.

Characterization of the dual ITK/JAK3 small molecule covalent inhibitor ATI-2138

Aclaris Therapeutics Inc (ATI)-2138 is a novel investigational covalent inhibitor of interleukin-2-inducible T cell kinase (ITK), resting lymphocyte kinase, and Janus kinase 3 (JAK3) in development for the treatment of autoimmune and inflammatory diseases. In this study, we evaluated the inhibitory effects of ATI-2138 on ITK and JAK3 signaling in cells and preclinical animal models and assessed the safety, tolerability, pharmacokinetics, and pharmacodynamics of ATI-2138 in healthy human participants. ATI-2138 potently, selectively, and irreversibly inhibited ITK, resting lymphocyte kinase, and JAK3 kinases with similar potency observed against ITK and JAK3 in biochemical and immune cell signaling assays. Translation from cellular and whole blood studies to in vivo models was observed, wherein ATI-2138 demonstrated disease-modifying activity in 2 rodent models of arthritis and an adoptive T cell model of colitis. In single and multiple ascending dose studies in healthy human participants, ATI-2138 had a favorable safety profile with linear pharmacokinetics. Biomarkers linked to both ITK and JAK3 activity were inhibited with ATI-2138 in an exposure-, dose-, and time-dependent manner and correlated with enzyme, cellular, whole blood, and rodent studies, thereby demonstrating predictive translational properties. As a potential first-in-class dual inhibitor of ITK and JAK3, ATI-2138 may be useful in the treatment of immunoinflammatory diseases. SIGNIFICANCE STATEMENT: Aclaris Therapeutics Inc (ATI)-2138 is a novel covalent inhibitor of interleukin-2-inducible T cell kinase (ITK)/resting lymphocyte kinase and Janus kinase 3 (JAK3). ATI-2138 inhibits JAK3 and ITK in enzyme and functional cellular assays, demonstrates disease-modifying activity in rodent models of arthritis and colitis, and inhibits biomarkers linked to both ITK and JAK3 activity in healthy human participants. With this dual kinase activity against components of these inflammatory signaling pathway, ATI-2138 has the potential for enhanced therapeutic efficacy in the treatment of autoimmune and chronic inflammatory disease.

Regulation of the microglial polarization for alleviating neuroinflammation in the pathogenesis and therapeutics of major depressive disorder

Major depressive disorder (MDD), as a multimodal neuropsychiatric and neurodegenerative illness with high prevalence and disability rates, has become a burden to world health and the economy that affects millions of individuals worldwide. Neuroinflammation, an atypical immune response occurring in the brain, is currently gaining more attention due to its association with MDD. Microglia, as immune sentinels, have a vital function in regulating neuroinflammatory reactions in the immune system of the central nervous system. From the perspective of steady-state branching states, they can transition phenotypes between two extremes, namely, M1 and M2 phenotypes are pro-inflammatory and anti-inflammatory, respectively. It has an intermediate transition state characterized by different transcriptional features and the release of inflammatory mediators. The timing regulation of inflammatory cytokine release is crucial for damage control and guiding microglia back to a steady state. The dysregulation can lead to exorbitant tissue injury and neuronal mortality, and targeting the cellular signaling pathway that serves as the regulatory basis for microglia is considered an essential pathway for treating MDD. However, the specific intervention targets and mechanisms of microglial activation pathways in neuroinflammation are still unclear. Therefore, the present review summarized and discussed various signaling pathways and effective intervention targets that trigger the activation of microglia from its branching state and emphasizes the mechanism of microglia-mediated neuroinflammation associated with MDD.

Disseminated Chickenpox Following Live Varicella Vaccination in a Crohn's Disease Patient on Combination Immunosuppression

Novel therapeutics used in the treatment of inflammatory bowel disease pose an increased risk of viral reactivation in patients. We present a case of a patient with refractory Crohn's disease (CD) who developed primary varicella (chickenpox) of a vaccine-viral strain after receiving combination immunosuppression with high-dose corticosteroids, tumor necrosis factor inhibitor (TNFi), and a Janus kinase inhibitor (JAKi) in the hospital. While this patient recovered and did not experience long term adverse effects, her case provides an opportunity for improvement. To improve safety, healthcare facilities should develop protocols that use electronic medical records enhanced with clinical decision support systems to identify and protect immunocompromised patients from inappropriate live vaccinations.

Innovative Approaches to Psoriasis: Small Molecules Targeting Key Signaling Pathways

BACKGROUND

Psoriasis (Pso) is a chronic, immune-mediated dermatological condition characterized by dysregulated inflammatory responses and the hyperproliferation of keratinocytes. Biologics, which target specific cytokines such as IL-17 and IL-23, have revolutionized the management by addressing key drivers of its pathophysiology. Despite their efficacy, biologics are not without limitations, including the need for intermittent administration and ongoing monitoring. In contrast, small molecules offer a promising alternative by selectively inhibiting key signaling pathways that modulate pro-inflammatory cytokines involved in the inflammatory cascade.

METHODS AND RESULTS

This review suggests a new therapeutic strategy for Pso treatment, emphasizing the intricate relationships between small molecules and important signaling pathways involved in the pathophysiology of skin conditions. Improving treatment outcomes and reducing the side effects associated with conventional medicines, this review aims to better understand how tailored small-molecule inhibitors might efficiently control these pathways. This creative approach promotes the creation of individualized treatment plans that can greatly enhance the quality of life of patients with Psoby utilizing the knowledge gathered from recent developments in signaling pathway research.

CONCLUSION

This review delves into the molecular mechanisms underlying Pso and explores how small molecules can be harnessed to enhance treatment outcomes, presenting a new paradigm for managing this chronic skin disorder.

Continuous Treatment with Tofacitinib but Not Filgotinib Is Effective in Non-Responders with Active Ulcerative Colitis: A Propensity Score-Matching Analysis

Background: Few studies have compared the efficacy and safety of Janus kinase (JAK) inhibitors in patients with ulcerative colitis (UC). We compared the real-world effectiveness and safety of tofacitinib (TOF) and filgotinib (FIL) as induction therapy for UC by propensity score-matching analysis. Methods: We enrolled 230 patients with active UC who received either TOF (n = 197) or FIL (n = 33) as induction therapy. The primary outcome was the clinical response at week 8, and the secondary outcomes were the clinical response/remission rates from weeks 2-8, including the course of patients without a clinical response/remission at week 4. Results: Propensity score-matching analysis revealed that the clinical response rate gradually increased to 72.2% at 8 weeks in the TOF group, whereas it tended to decrease to 48.5% in the FIL group. Clinical remission rates increased from 2 (36.7% vs. 36.7%) to 8 weeks (63.6% vs. 48.5%) after treatment in the TOF and FIL groups, respectively. The clinical response rate was higher in the TOF group than in the FIL group at week 8 in patients without a clinical response at week 4 (38.5% vs. 0%; p = 0.011). The clinical remission rate was also higher in the TOF group than in the FIL group at week 8 in patients without clinical remission at week 4 (50.0% vs. 16.7%; p = 0.046). The incident rates of infection and anemia were higher in the TOF group than in the FIL group. Conclusions: TOF may be more effective than FIL at 8 weeks for patients with UC who do not respond to treatment within the first 4 weeks.

Molecular basis of JAK kinase regulation guiding therapeutic approaches: Evaluating the JAK3 pseudokinase domain as a drug target

Janus kinases (JAK1-3, TYK2) are critical mediators of cytokine signaling and their role in hematological and inflammatory and autoimmune diseases has sparked widespread interest in their therapeutic targeting. JAKs have unique tandem kinase structure consisting of an active tyrosine kinase domain adjacent to a pseudokinase domain that is a hotspot for pathogenic mutations. The development of JAK inhibitors has focused on the active kinase domain and the developed drugs have demonstrated good clinical efficacy but due to off-target inhibition cause also side-effects and carry a black box warning limiting their use. Our understanding of the regulatory function of the pseudokinase domain in physiological and pathological signaling has improved substantially. The pseudokinase domain maintains the inactive state of JAKs in the absence of cytokine stimulation but it has also a key role in physiological and mutation-driven activation process. Furthermore, the pseudokinase domain has favourable structural characteristics for selective targeting of cytokine signaling, such as unique mode of ATP-binding, and the first pseudokinase targeting inhibitor for TYK2 has been approved for clinical use. Here we describe the recent functional and structural knowledge of JAK signaling and their therapeutic targeting, and present data evaluating the druggability of the JAK3 pseudokinase domain.

Granuloma Annulare Exhibits Mixed Immune and Macrophage Polarization Profiles with Spatial Transcriptomics

Granuloma annulare (GA) is an idiopathic condition characterized by granulomatous inflammation in the skin. Prior studies have suggested that GA develops from various triggers, leading to a complex interplay involving innate and adaptive immunity, tissue remodeling, and fibrosis. Macrophages are the major immune cells comprising GA granulomas; however, the molecular drivers and inflammatory signaling cascade behind macrophage activation are poorly understood. Histologically, GA exhibits both palisaded and interstitial patterns on histology; however, the molecular composition of GA at the spatial level remains unexplored. GA is a condition without Food and Drug Administration-approved therapies despite the significant impact of GA on QOL. Spatial transcriptomics is a valuable tool for profiling localized, genome-wide gene expression changes across tissues, with emerging applications in clinical medicine. To improve our understanding of the spatially localized gene expression patterns underlying GA, we profiled the spatial gene expression landscape from 6 patients with GA. Our findings revealed mixed T helper 1 and T helper 2 signals comprising the GA microenvironment and spatially distinct M1 and M2 macrophage polarization characteristics. IFN-γ and TNF signals emerged as important regulators of GA granulomatous inflammation, and IL-32 emerged as a key driver of granulomatous inflammation. Overall, our spatial transcriptomics data indicate that GA exhibits mixed immune and macrophage polarization.

Research progress on the pathogenesis of psoriasis and its small molecule inhibitors

Psoriasis is a prevalent chronic systemic immune disease characterized by T-cellmediated hyperproliferation of keratinized cells. Among its various manifestations, plaque-type psoriasis is the most common. Treatment options for psoriasis encompass topical medications, biological therapies, phototherapy techniques, and others. However, traditional treatments are associated with numerous side effects. In contrast, targeted therapy has garnered increasing attention due to its high selectivity, strong safety profile, and favorable therapeutic outcomes. Patients with psoriasis lesions exhibit elevated levels of proinflammatory cytokines compared with the general population. These proinflammatory cytokines have been implicated in mediating psoriasis pathogenesis by inducing keratinocyte proliferation through multiple signaling pathways within the body. This study will delve into the Janus kinase-signal transducers and activators of transcription, phosphatidylinositol 3 kinase (PI3K)-protein kinase B (PKB, also known as AKT), and nuclear factor Kappa-light-chain-enhancer of activated B cells signaling pathways to elucidate their roles in mediating psoriasis pathogenesis. In addition, we will summarize potential targets relevant to the treatment of psoriasis and discuss the design and activity assessment of their inhibitors. It also provides new insights for further in-depth study of psoriasis and development of novel molecularly targeted inhibitors.

Therapeutic JAK1 Inhibition Reverses Lupus Nephritis in a Mouse Model and Demonstrates Transcriptional Changes Consistent With Human Disease

OBJECTIVE

Janus kinase family members are essential for signaling by multiple cytokines, including many implicated in systemic lupus erythematosus (SLE) pathogenesis. To test whether inhibition of JAK1 signaling can be efficacious in SLE, we used a JAK1-selective inhibitor (ABT-317) and evaluated its ability to ameliorate disease in murine SLE.

METHODS

Efficacy of ABT-317 was evaluated using NZB/W-F1 mice treated prophylactically and therapeutically. Primary endpoints were proteinuria, survival, and saliva production. Other endpoints included histological analysis of kidneys and salivary glands, flow cytometric analysis of splenic cell populations, and gene expression analysis by RNA sequencing in the kidneys, salivary glands, and blood. Publicly available human kidney gene transcription data were used to assess the translatability of the mouse findings.

RESULTS

ABT-317 was efficacious when dosed prophylactically and prevented disease for up to two months after treatment cessation. When dosed therapeutically, ABT-317 quickly reversed severe proteinuria and restored saliva production, as well as diminished kidney and salivary gland inflammation. ABT-317-induced changes in glomerular morphology coincided with normalization of a human nephrotic gene signature, suggesting translatability to human lupus nephritis (LN).

CONCLUSION

JAK1 inhibition prevented and reversed kidney and salivary gland manifestations of murine lupus with long-lasting effects after treatment cessation. These data, along with the presence of JAK1 and nephrotic gene signatures in human LN glomeruli, suggest that a JAK1-selective inhibitor may be an effective therapeutic in the treatment of human SLE and LN.

Virus-induced brain pathology and the neuroinflammation-inflammation continuum: the neurochemists view

Fascinatingly, an abundance of recent studies has subscribed to the importance of cytotoxic immune mechanisms that appear to increase the risk/trigger for many progressive neurodegenerative disorders, including Parkinson's disease (PD), Alzheimer's disease (AD), amyotrophic lateral sclerosis, and multiple sclerosis. Events associated with the neuroinflammatory cascades, such as ageing, immunologic dysfunction, and eventually disruption of the blood-brain barrier and the "cytokine storm", appear to be orchestrated mainly through the activation of microglial cells and communication with the neurons. The inflammatory processes prompt cellular protein dyshomeostasis. Parkinson's and Alzheimer's disease share a common feature marked by characteristic pathological hallmarks of abnormal neuronal protein accumulation. These Lewy bodies contain misfolded α-synuclein aggregates in PD or in the case of AD, they are Aβ deposits and tau-containing neurofibrillary tangles. Subsequently, these abnormal protein aggregates further elicit neurotoxic processes and events which contribute to the onset of neurodegeneration and to its progression including aggravation of neuroinflammation. However, there is a caveat for exclusively linking neuroinflammation with neurodegeneration, since it's highly unlikely that immune dysregulation is the only factor that contributes to the manifestation of many of these neurodegenerative disorders. It is unquestionably a complex interaction with other factors such as genetics, age, and environment. This endorses the "multiple hit hypothesis". Consequently, if the host has a genetic susceptibility coupled to an age-related weakened immune system, this makes them more susceptible to the virus/bacteria-related infection. This may trigger the onset of chronic cytotoxic neuroinflammatory processes leading to protein dyshomeostasis and accumulation, and finally, these events lead to neuronal destruction. Here, we differentiate "neuroinflammation" and "inflammation" with regard to the involvement of the blood-brain barrier, which seems to be intact in the case of neuroinflammation but defect in the case of inflammation. There is a neuroinflammation-inflammation continuum with regard to virus-induced brain affection. Therefore, we propose a staging of this process, which might be further developed by adding blood- and CSF parameters, their stage-dependent composition and stage-dependent severeness grade. If so, this might be suitable to optimise therapeutic strategies to fight brain neuroinflammation in its beginning and avoid inflammation at all.

Exploring the Antiviral Potential of Artemisia annua Through JAK-STAT Pathway Targeting: A Network Pharmacology Approach

BACKGROUND

Artemisia annua, a plant with antiviral potential, has shown promise against various viral infections, yet its mechanisms of action are not fully understood. This study explores A. annua's antiviral effects using network pharmacology and molecular docking, focusing on key active compounds and their interactions with viral protein targets, particularly within the JAK-STAT signaling pathway-a critical mediator of immune responses to viral infections.

METHODS

From the TCMSP database, we identified eight active compounds and 335 drug targets for A. annua, with 19 intersecting targets between A. annua compounds and viral proteins. A protein-protein interaction (PPI) network highlighted 10 key hub genes, analyzed further through Gene Ontology (GO) and KEGG pathways to understand their immune and antiviral roles. ADMET properties of the active compound Patuletin (MOL004112) were assessed, followed by 200 ns molecular dynamics simulations to examine its stability in complex with JAK2.

RESULTS

PPI analysis identified JAK2, MAPK3, MAPK1, JAK1, PTPN1, HSPA8, TYK2, RAF1, MAPT, and HMOX1 as key hub genes, with JAK2 emerging as a critical regulator of immune and antiviral pathways. ADMET analysis confirmed Patuletin's favorable pharmacokinetic properties, and molecular dynamics simulations showed a stable Patuletin-JAK2 complex, with FEL analysis indicating minimal disruption to JAK2's intrinsic flexibility.

CONCLUSIONS

These findings highlight JAK2 as a promising target in the antiviral activity of A. annua compounds, particularly Patuletin, supporting its potential as an antiviral agent and providing a foundation for further research on A. annua's therapeutic applications.

Nutraceuticals as Modulators of Molecular Placental Pathways: Their Potential to Prevent and Support the Treatment of Preeclampsia

Preeclampsia (PE) is a serious condition characterized by new-onset hypertension and proteinuria or organ dysfunction after the 20th week of gestation, making it a leading cause of maternal and fetal mortality worldwide. Despite extensive research, significant gaps remain in understanding the mechanisms underlying PE, contributing to the ineffectiveness of current prevention and treatment strategies. Consequently, premature cesarean sections often become the primary intervention to safeguard maternal and fetal health. Emerging evidence indicates that placental insufficiency, driven by molecular disturbances, plays a central role in the development of PE. Additionally, the maternal microbiome may be implicated in the pathomechanism of preeclampsia by secreting metabolites that influence maternal inflammation and oxidative stress, thereby affecting placental health. Given the limitations of pharmaceuticals during pregnancy due to potential risks to fetal development and concerns about teratogenic effects, nutraceuticals may provide safer alternatives. Nutraceuticals are food products or dietary supplements that offer health benefits beyond basic nutrition, including plant extracts or probiotics. Their historical use in traditional medicine has provided valuable insights into their safety and efficacy, including for pregnant women. This review will examine how the adoption of nutraceuticals can enhance dysregulated placental pathways, potentially offering benefits in the prevention and treatment of preeclampsia.

Design, synthesis and activity screening of cedrol derivatives as small molecule JAK3 inhibitors

The JAK-STAT signalling pathway is considered to be a significant role involved in the regulation of inflammatory diseases and immune responses, which indicate that specific inhibition of JAK-STAT pathway would be a potential key strategy for RA (Rheumatoid arthritis) treatment. Cedrol (CE), found from ginger by our group earlier, has been proven to play an excellent role in ameliorating RA via acting on JAK3. In this study, 27 new (1, 3-28), along with one known (2) derivatives of CE were synthesized by using chloroacetic acid and acryloyl chloride as intermediate ligands. In vitro, the inhibition effect on JAK kinases were performed using HTRF (Homogenous Time-Resolved Fluorescence) detection technology, which is more convenient and stable than traditional methods. The results compared with the secretion of LPS-induced p-JAK3 can better reflect the true kinase-selective effect of the compounds. Compound 22 was identified as a potent inhibitor to reduce the secretion of LPS-induced p-JAK3 with a dose-dependent manner. Given these results, compound 22 could serve as a favourable inhibitor of JAK3 for further research.

Advances in psoriasis research: From pathogenesis to therapeutics

Psoriasis is a chronic inflammatory condition affecting approximately 2 % to 3 % of the global population. The pathogenesis of psoriasis is complex, involving immune dysregulation, hyperproliferation and angiogenesis. It is a multifactorial disease which is influenced by genetic and environmental factors. The development of various therapeutic agents, such as JAK inhibitors, small molecules, and biologics with potential anti-psoriatic properties was possible with the vast understanding of the pathogenesis of psoriasis. Various signalling pathways, including NF-κB, JAK-STAT, S1P, PDE-4, and A3AR that are involved in the pathogenesis of psoriasis as well as the preclinical models utilised in the research of psoriasis have been highlighted in this review. The review also focuses on technological advancements that have contributed to a better understanding of psoriasis. Then, the molecules targeting the respective signalling pathways that are still under clinical trials or recently approved as well as the latest breakthroughs in therapeutic and drug delivery approaches that can contribute to the improvement in the management of psoriasis are highlighted in this review. This review provides an extensive understanding of the current state of research in psoriasis, giving rise to opportunities for researchers to discover future therapeutic breakthroughs and personalised interventions. Efficient treatment options for individuals with psoriasis can be achieved by an extensive understanding of pathogenesis, therapeutic agents, and novel drug delivery strategies.

Herpes Zoster and Venous Thromboembolism Following Upadacitinib Treatment for Severe Atopic Dermatitis

New medications targeting the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway have been developed through emerging biologics research. However, due to documented adverse effects, including herpes zoster (HZ) and venous thromboembolism (VTE), an extensive patient workup and counseling are necessary before prescribing. We present the case of an 81-year-old patient with severe atopic dermatitis on upadacitinib, a selective JAK1 inhibitor, who developed HZ and VTE, requiring hospitalization. This study emphasizes the need for further research, continuous monitoring, and risk management for HZ and VTE in patients undergoing upadacitinib treatment, especially in high-risk populations.

[Janus kinase inhibitors for skin disorders]

Immune factors such as interferon‑ɣ and interleukin 4 belong to the group of cytokines that are dependent on type I/II receptors for their signal transmission. Upon activation, these receptors transmit their signal to the cell nucleus and, thus, modulate gene transcription via a signaling cascade consisting of Janus kinases (JAK). This family of four kinases (JAK 1, JAK 2, JAK 3, and tyrosine kinase 2 (TYK2)) subsequently activate members of the signal transducer and activator of transcription (STAT). This finding turned the JAK/STAT signaling pathway into a pharmacological target for the treatment of inflammatory diseases in which cytokines using type I/II receptors play a pathogenic role. In 2018, the European Medicines Agency (EMA) approved tofacitinib for the treatment of psoriatic arthritis. This was the first approval of a JAK/STAT pathway inhibitor for patients treated by dermatologists and rheumatologists. Since then, several new JAK inhibitors have been approved for dermatologic diseases such as atopic dermatitis, alopecia areata, vitiligo, and plaque-type psoriasis. In addition, JAK inhibitors are being investigated for the treatment of many other skin diseases. Thus, systemic JAK inhibitors complete the spectrum of immunotherapeutics with a broader immunological approach compared to monoclonal antibodies. The low molecular weight of JAK inhibitors enables the preparation of these drugs for both systemic and topical administration. Their utilization could represent a valuable alternative to topical steroids. The safety profile of JAK inhibitors must be taken into account. Possible long-term effects may become apparent in the next few years. This article describes both approved JAK inhibitors and relevant new JAK inhibitors that are promising candidates for approval as therapeutics in dermatology.

Game changer: How Janus kinase inhibitors are reshaping the landscape of ulcerative colitis management

Recent advancements in the treatment landscape of ulcerative colitis (UC) have ushered in a new era of possibilities, particularly with the introduction of Janus kinase (JAK)-signal transducer and activator of transcription inhibitors. These novel agents offer a paradigm shift in UC management by targeting key signaling pathways involved in inflammatory processes. With approved JAK inhibitors (JAKis), such as tofacitinib, filgotinib, and upadacitinib, clinicians now have powerful tools to modulate immune responses and gene expression, potentially revolutionizing the treatment algorithm for UC. Clinical trials have demonstrated the efficacy of JAKis in inducing and maintaining remission, presenting viable options for patients who have failed conventional therapies. Real-world data support the use of JAKis not only as first-line treatments but also in subsequent lines of therapy, particularly in patients with aggressive disease phenotypes or refractory to biologic agents. The rapid onset of action and potency of JAKis have broadened the possibilities in the management strategies of UC, offering timely relief for patients with active disease and facilitating personalized treatment approaches. Despite safety concerns, including cardiovascular risks and infections, ongoing research and post-marketing surveillance will continue to refine our understanding of the risk-benefit profile of JAKis in UC management.

Gut instinct: harnessing the power of probiotics to tame pathogenic signaling pathways in ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease (IBD) marked by persistent inflammation of the mucosal lining of the large intestine, leading to debilitating symptoms and reduced quality of life. Emerging evidence suggests that an imbalance of the gut microbiota plays a crucial role in UC pathogenesis, and various signaling pathways are implicated in the dysregulated immune response. Probiotics are live microorganisms that confer health benefits to the host, have attracted significant attention for their potential to restore gut microbial balance and ameliorate inflammation in UC. Recent studies have elucidated the mechanisms by which probiotics modulate these signaling pathways, often by producing anti-inflammatory molecules and promoting regulatory immune cell function. For example, probiotics can inhibit the nuclear factor-κB (NF-κB) pathway by stabilizing Inhibitor of kappa B alpha (IκBα), dampening the production of proinflammatory cytokines. Similarly, probiotics can modulate the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway, suppressing the activation of STAT1 and STAT3 and thus reducing the inflammatory response. A better understanding of the underlying mechanisms of probiotics in modulating pathogenic signaling pathways in UC will pave the way for developing more effective probiotic-based therapies. In this review, we explore the mechanistic role of probiotics in the attenuation of pathogenic signaling pathways, including NF-κB, JAK/STAT, mitogen-activated protein kinases (MAPKs), Wnt/β-catenin, the nucleotide-binding domain (NOD)-, leucine-rich repeat (LRR)- and pyrin domain-containing protein 3 (NLRP3) inflammasome, Toll-like receptors (TLRs), interleukin-23 (IL-23)/IL-17 signaling pathway in UC.

Biological Evaluations and Computer-Aided Approaches of Janus Kinases 2 and 3 Inhibitors for Cancer Treatment: A Review

Cancer remains one of the leading diseases of mortality worldwide. Janus kinases 2/3 (JAK2/3) have been considered a drug target for the development of drugs to treat different types of cancer. JAK2/3 play a critical role in innate immunity, inflammation, and hematopoiesis by mediating the signaling of numerous cytokines, growth factors, and interferons. The current focus is to develop new selective inhibitors for each JAK type. In this review, the current strategies of computer-aided studies, and biological evaluations against JAK2/3 are addressed. We found that the new synthesized JAK2/3 inhibitors are prone to containing heterocyclic aromatic rings such as pyrimidine, pyridine, and pyrazolo [3,4-d]pyrimidine. Moreover, inhibitors of natural origin derived from plant extracts and insects have shown suitable inhibitory capacities. Computer-assisted studies have shown the important features of inhibitors for JAK2/3 binding. Biological evaluations showed that the inhibition of the JAK receptor affects its related signaling pathway. Although the reviewed compounds showed good inhibitory capacity in vitro and in vivo, more in-depth studies are needed to advance toward full approval of cancer treatments in humans.

Discovery of a potent and selective JAK1-targeting PROTAC degrader with anti-tumor activities

Aberrant activation of the JAK-STAT pathway is evident in various human diseases including cancers. Proteolysis targeting chimeras (PROTACs) provide an attractive strategy for developing novel JAK-targeting drugs. Herein, a series of CRBN-directed JAK-targeting PROTACs were designed and synthesized utilizing a JAK1/JAK2 dual inhibitor-momelotinib as the warhead. The most promising compound 10c exhibited both good enzymatic potency and cellular antiproliferative effects. Western blot analysis revealed that compound 10c effectively and selectively degraded JAK1 in a proteasome-dependent manner (DC50 = 214 nM). Moreover, PROTAC 10c significantly suppressed JAK1 and its key downstream signaling. Together, compound 10c may serve as a novel lead compound for antitumor drug discovery.

Peripheral nervous system immune-related adverse events due to checkpoint inhibition

Immune checkpoint inhibitors have revolutionized cancer therapy and are increasingly used to treat a wide range of oncological conditions, with dramatic benefits for many patients. Unfortunately, the resulting increase in T cell effector function often results in immune-related adverse events (irAEs), which can involve any organ system, including the central nervous system (CNS) and peripheral nervous system (PNS). Neurological irAEs involve the PNS in two-thirds of affected patients. Muscle involvement (immune-related myopathy) is the most common PNS irAE and can be associated with neuromuscular junction involvement. Immune-related peripheral neuropathy most commonly takes the form of polyradiculoneuropathy or cranial neuropathies. Immune-related myopathy (with or without neuromuscular junction involvement) often occurs along with immune-related myocarditis, and this overlap syndrome is associated with substantially increased mortality. This Review focuses on PNS adverse events associated with immune checkpoint inhibition. Underlying pathophysiological mechanisms are discussed, including antigen homology between self and tumour, epitope spreading and activation of pre-existing autoreactive T cells. An overview of current approaches to clinical management is provided, including cytokine-directed therapies that aim to decouple anticancer immunity from autoimmunity and emerging treatments for patients with severe (life-threatening) presentations.

Development of a Formulation and In Vitro Evaluation of a Pulmonary Drug Delivery System for a Novel Janus Kinase (JAK) Inhibitor, CPL409116

The pursuit of targeted therapies for cytokine-dependent diseases has led to the discovery of Janus kinase (JAK) inhibitors, a promising class of drugs. Among them, CPL409116, a selective dual JAK and rho-associated protein kinase inhibitor (ROCK), has demonstrated potential for treating conditions such as pulmonary fibrosis exacerbated by the COVID-19 pandemic. This study investigated the feasibility of delivering CPL409116 via inhalation, with the aim of minimizing the systemic adverse effects associated with oral administration. Two micronization methods, jet milling and spray drying, were assessed for CPL409116, with spray drying chosen for its ability to produce an amorphous form of the compound. Moreover, parameters such as the mixing energy, drug load, and force control agent significantly influenced the fine particle fraction (FPF), a critical parameter for pulmonary drug delivery. This study provides insights into optimizing the formulation parameters to enhance the delivery efficiency of CPL409116 to the lungs, offering potential for improved therapeutic outcomes in cytokine-dependent pulmonary diseases.

The JAK-STAT pathway: from structural biology to cytokine engineering

The Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway serves as a paradigm for signal transduction from the extracellular environment to the nucleus. It plays a pivotal role in physiological functions, such as hematopoiesis, immune balance, tissue homeostasis, and surveillance against tumors. Dysregulation of this pathway may lead to various disease conditions such as immune deficiencies, autoimmune diseases, hematologic disorders, and cancer. Due to its critical role in maintaining human health and involvement in disease, extensive studies have been conducted on this pathway, ranging from basic research to medical applications. Advances in the structural biology of this pathway have enabled us to gain insights into how the signaling cascade operates at the molecular level, laying the groundwork for therapeutic development targeting this pathway. Various strategies have been developed to restore its normal function, with promising therapeutic potential. Enhanced comprehension of these molecular mechanisms, combined with advances in protein engineering methodologies, has allowed us to engineer cytokines with tailored properties for targeted therapeutic applications, thereby enhancing their efficiency and safety. In this review, we outline the structural basis that governs key nodes in this pathway, offering a comprehensive overview of the signal transduction process. Furthermore, we explore recent advances in cytokine engineering for therapeutic development in this pathway.

Progress on the Anti-Inflammatory Activity and Structure-Efficacy Relationship of Polysaccharides from Medical and Edible Homologous Traditional Chinese Medicines

Medicinal food varieties developed according to the theory of medical and edible homologues are effective at preventing and treating chronic diseases and in health care. As of 2022, 110 types of traditional Chinese medicines from the same source of medicine and food have been published by the National Health Commission. Inflammation is the immune system's first response to injury, infection, and stress. Chronic inflammation is closely related to many diseases such as atherosclerosis and cancer. Therefore, timely intervention for inflammation is the mainstay treatment for other complex diseases. However, some traditional anti-inflammatory drugs on the market are commonly associated with a number of adverse effects, which seriously affect the health and safety of patients. Therefore, the in-depth development of new safe, harmless, and effective anti-inflammatory drugs has become a hot topic of research and an urgent clinical need. Polysaccharides, one of the main active ingredients of medical and edible homologous traditional Chinese medicines (MEHTCMs), have been confirmed by a large number of studies to exert anti-inflammatory effects through multiple targets and are considered potential natural anti-inflammatory drugs. In addition, the structure of medical and edible homologous traditional Chinese medicines' polysaccharides (MEHTCMPs) may be the key factor determining their anti-inflammatory activity, which makes the underlying the anti-inflammatory effects of polysaccharides and their structure-efficacy relationship hot topics of domestic and international research. However, due to the limitations of the current analytical techniques and tools, the structures have not been fully elucidated and the structure-efficacy relationship is relatively ambiguous, which are some of the difficulties in the process of developing and utilizing MEHTCMPs as novel anti-inflammatory drugs in the future. For this reason, this paper summarizes the potential anti-inflammatory mechanisms of MEHTCMPs, such as the regulation of the Toll-like receptor-related signaling pathway, MAPK signaling pathway, JAK-STAT signaling pathway, NLRP3 signaling pathway, PI3K-AKT signaling pathway, PPAR-γ signaling pathway, Nrf2-HO-1 signaling pathway, and the regulation of intestinal flora, and it systematically analyzes and evaluates the relationships between the anti-inflammatory activity of MEHTCMPs and their structures.

Efficacy and safety of delgocitinib cream in adults with moderate to severe chronic hand eczema (DELTA 1 and DELTA 2): results from multicentre, randomised, controlled, double-blind, phase 3 trials

BACKGROUND

Chronic hand eczema is a fluctuating, inflammatory, pruritic, often painful disease of hands and wrists that strongly impacts quality of life and occupational capabilities of patients. The aim of phase 3 DELTA 1 and DELTA 2 was to assess the efficacy and safety of twice-daily applications of the topical pan-Janus kinase inhibitor delgocitinib cream 20 mg/g versus cream vehicle in adults with moderate to severe chronic hand eczema.

METHODS

Both trials were randomised, double-blinded, and vehicle-controlled, with DELTA 1 being conducted at 53 trial centres in Canada, France, Germany, Italy, Poland, and the UK and DELTA 2 at 50 trial centres in Belgium, Canada, Denmark, Germany, the Netherlands, Poland, and Spain. Adults (aged ≥18 years) with moderate to severe chronic hand eczema were randomly assigned 2:1 to twice-daily delgocitinib cream 20 mg/g or cream vehicle for 16 weeks. The primary endpoint was Investigator's Global Assessment for Chronic Hand Eczema (IGA-CHE) treatment success at week 16, defined as IGA-CHE score of 0 (clear) or 1 (almost clear, defined as only barely perceptible erythema). Efficacy and safety were assessed in all patients who were exposed to trial treatment. These trials are registered with ClinicalTrials.gov, NCT04871711 and NCT04872101.

FINDINGS

Between May 10, 2021, and Oct 31, 2022, 487 patients (181 male and 306 female) were enrolled in DELTA 1; between May 25, 2021, and Jan 6, 2023, 473 patients (161 male and 312 female) were enrolled in DELTA 2. 325 patients in DELTA 1 and 314 in DELTA 2 were assigned to delgocitinib cream; 162 patients in DELTA 1 and 159 in DELTA 2 were assigned to cream vehicle. At week 16, a greater proportion of delgocitinib-treated patients versus cream vehicle patients had IGA-CHE treatment success (64 [20%] of 325 vs 16 [10%] of 162 in DELTA 1 and 91 [29%] of 313 vs 11 [7%] of 159 in DELTA 2; both trials p≤0·0055). The proportion of patients who reported adverse events was similar with delgocitinib (147 [45%] of 325 in DELTA 1 and 143 [46%] of 313 in DELTA 2) and the cream vehicle (82 [51%] of 162 in DELTA 1 and 71 [45%] of 159 in DELTA 2). Most frequent adverse events occurring in at least 2% of patients were similar in both treatment groups and included COVID-19 and nasopharyngitis.

INTERPRETATION

Overall, delgocitinib cream showed superior efficacy versus cream vehicle and was well tolerated over 16 weeks. These results support the clinical benefit of delgocitinib cream as a potential treatment option for patients with moderate to severe chronic hand eczema, who are unable to adequately control their disease with basic skin care practices and topical corticosteroids.

FUNDING

LEO Pharma.

Non-Receptor Tyrosine Kinases: Their Structure and Mechanistic Role in Tumor Progression and Resistance

Protein tyrosine kinases (PTKs) function as key molecules in the signaling pathways in addition to their impact as a therapeutic target for the treatment of many human diseases, including cancer. PTKs are characterized by their ability to phosphorylate serine, threonine, or tyrosine residues and can thereby rapidly and reversibly alter the function of their protein substrates in the form of significant changes in protein confirmation and affinity for their interaction with protein partners to drive cellular functions under normal and pathological conditions. PTKs are classified into two groups: one of which represents tyrosine kinases, while the other one includes the members of the serine/threonine kinases. The group of tyrosine kinases is subdivided into subgroups: one of them includes the member of receptor tyrosine kinases (RTKs), while the other subgroup includes the member of non-receptor tyrosine kinases (NRTKs). Both these kinase groups function as an "on" or "off" switch in many cellular functions. NRTKs are enzymes which are overexpressed and activated in many cancer types and regulate variable cellular functions in response to extracellular signaling-dependent mechanisms. NRTK-mediated different cellular functions are regulated by kinase-dependent and kinase-independent mechanisms either in the cytoplasm or in the nucleus. Thus, targeting NRTKs is of great interest to improve the treatment strategy of different tumor types. This review deals with the structure and mechanistic role of NRTKs in tumor progression and resistance and their importance as therapeutic targets in tumor therapy.

Cloning and expression analysis of Janus activated kinase family genes from spotted seabass (Lateolabrax maculatus)

Janus kinases (JAKs) are important components of the JAK-STAT signaling pathway and play vital roles in innate immunity, autoimmune diseases, and inflammation. However, information about JAKs remains largely unknown in the spotted seabass, a fish species of Perciformes with great commercial value in the aquaculture industry. The aims of this study are to obtain the complete cDNA sequences of JAKs (JAK1, JAK2A, JAK2B, JAK3 and TYK2) from spotted seabass and to investigate their roles upon stimulation with lipopolysaccharides (LPS) and Edwardsiella tarda, using RT-PCR, PCR and qRT-PCR methods. All five JAK genes from the spotted seabass, each encode more than 1100 amino acids residues. JAK1 and JAK3 consist of 24 exons and 23 introns, whereas JAK2A, JAK2B and TYK2 consist of 23 exons and 22 introns. Furthermore, these five spotted seabass JAKs share high sequence identities with those of other fish species in protein domain analysis, synteny analysis, and phylogenetic analysis. Moreover, these five JAK genes were ubiquitously expressed in all tissues examined from healthy fish, and inducible expressions of JAKs were observed in the intestine, gill, head kidney, and spleen following LPS treatment or E. tarda infection. These findings indicate that all these JAK genes are involved in the antibacterial immunity of the spotted seabass and provide a basis for further understanding the mechanism of JAKs antibacterial response in the spotted sea bass.

Revisiting Structure-activity Relationships: Unleashing the potential of selective Janus kinase 1 inhibitors

Janus kinases (JAKs), a kind of non-receptor tyrosine kinases, the function has been implicated in the regulation of cell proliferation, differentiation and apoptosis, immune, inflammatory response and malignancies. Among them, JAK1 represents an essential target for modulating cytokines involved in inflammation and immune function. Rheumatoid arthritis, atopic dermatitis, ulcerative colitis and psoriatic arthritis are areas where approved JAK1 drugs have been applied for the treatment. In the review, we provided a brief introduction to JAK1 inhibitors in market and clinical trials. The structures of high active JAK1 compounds (IC50 ≤ 0.1 nM) were highlighted, with primary focus on structure-activity relationship and selectivity. Moreover, the druggability processes of approved drugs and high active compounds were analyzed. In addition, the issues involved in JAK1 compounds clinical application as well as strategies to surmount these challenges, were discussed.

Deucravacitinib: moderate-to-severe plaque psoriasis preventable?

Psoriasis is a persistent, inflammatory, and autoimmune condition that is difficult to treat. Estimates of the prevalence of psoriasis in people range from 0.27 % (95 % confidence interval 0.17 to 0.36) to 11.4 %, depending on factors such as age, sex, geography, ethnicity, genetics, and environmental factors. While systemic treatments are typically required for patients with moderate-to-severe instances of psoriasis, topical therapies are frequently effective for treating minor forms. In fact, phototherapy is frequently constrained by logistical considerations, and conventional systemic therapies are frequently avoided due to contraindications or the danger of adverse outcomes. In order to better serve the patient and achieve a greater level of quality of life, especially in order to sustain long-term efficacy, there is still a need for innovative therapies, which are always welcomed. Deucravacitinib is a first-in-class oral tyrosine kinase 2 (TYK2) inhibitor that is extremely selective. Through an allosteric mechanism, it stabilises an inhibitory connection between the regulatory and catalytic domains of TYK2's pseudokinase regulatory domain, which is catalytically inactive. This can be used to treat a variety of immune-mediated conditions, such as inflammatory bowel disease, lupus, psoriatic arthritis, and psoriasis. US-FDA has approved this drug on 9 September 2022 for the treatment of adults with moderate-to-severe plaque psoriasis who are candidates for systemic therapy or phototherapy. This article aims to review the current knowledge on the efficacy and safety of deucravacitinib for the management of psoriasis.

Field-based 3D-QSAR for tyrosine protein kinase JAK-2 inhibitors

The present work aimed to develop a Field-based 3D-QSAR model with existing JAK-2 inhibitors. The JAK-STAT pathway is known to play a role in the development of autoimmune diseases, including rheumatoid arthritis, ulcerative colitis, and Crohn's disease. Dysregulation of JAK-STAT is also linked to the development of myelofibrosis and other myeloproliferative diseases. JAK antagonists can be used in many areas of medicine. There are many compounds that already show inhibition of Jak-2. We have developed a Field-based 3D QSAR model which showed good correlation values (r2 0.884 and q2 0.67) with an external test set regression pred_r2 0.562. Various properties, such as electronegativity, electro positivity, hydrophobicity, and shape features, were studied under the activity atlas to determine the inhibitory potential of ligands. These were also identified as important structural features responsible for biological activity. We performed virtual screening based on the pharmacophore features of the co-crystal ligand (PDB ID: 3KRR) and a dataset of NPS was selected with a RMSD value less than 0.8. The developed 3D QSAR model was used to screen ligands and calculate the predicted JAK-2 inhibition activity (pKi). The results of the virtual screening were validated using molecular docking and molecular dynamics simulations. SNP1 (SN00154718) and SNP2 (SN00213825) showed binding affinity of -11.16 and -11.08 kcal/mol, respectively, which were very close to the crystal ligand of 3KRR, -11.67 kcal/mol. The RMSD plot of the protein-ligand complex of SNP1 and 3KRR showed stable interactions with an average RMSD of 2.89 Å. Thus, a statistically robust 3D QSAR model could reveal more inhibitors and aid in the design of novel JAK-2 inhibitors.