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.

The efficacy and safety of JAK inhibitors in patients with adult-onset still's disease: A meta-analysis and systematic review.

OBJECTIVE: To evaluate the efficacy and safety of Janus kinases inhibitors (JAKi) for adult-onset Still's disease (AOSD) patients. METHODS: We searched the Embase, PubMed, the Cochrane Central Register of Controlled Trials (CENTRAL), and the China National Knowledge Infrastructure (CNKI) from inception up to 22 October 2023. The results were supplemented by a backward search of relevant publications. Two authors independently selected trials. The available studies were comprehensively reviewed and analysed. RESULTS: A total of 9 studies with a total of 35 patients were included in the review. Of these patients, 17 (48.6%) patients were treated with tofacitinib, 14 (40%) with baricitinib, 4 (11.4%) with ruxolitinib and 1 (2.9%) with upadacitinib. After treatment with JAKi, 17 (48.6%) patients showed complete remission, 12 (34.3%) patients showed partial remission, and 7 (20%) patients showed loss of efficacy or relapse. The use of ruxolitinib showed a remission rate of 100% in AOSD patients with macrophage activation syndrome (MAS). The incidence of adverse events (AEs) reported were mild and rare overall. Most AEs were abnormal lipid parameters (9.7%), bacterial pneumonia (3.2%), organised pneumonia (3.2%), diarrhoea (3.2%), increased heart rate (3.2%), menometrorrhagia (3.2%) and leukopenia (3.2%). One patient died from bacterial pneumonia. CONCLUSION: JAKi therapy may be an option for patients with AOSD, especially for refractory AOSD. For patients with AOSD complicated by MAS, ruxolitinib seems to be a better choice than other JAKi agents. Although our study shows that JAKi are well tolerated in AOSD patients, we still need to be on the lookout for fatal infections.

Monoclonal Antibodies: Current Advancements and Future Potential for Atopic Dermatitis Therapy.

BACKGROUND: Atopic Dermatitis (AD) is an inflammatory skin condition with a severe itch. The topical therapy using corticosteroids is not sufficient for the effective therapy of moderate to severe cases of AD. The investigation and development of immunological targetspecific human monoclonal antibodies have changed the paradigm for the therapy of moderate to severe cases of AD. OBJECTIVE: The establishment of target-specific, tolerable, and efficacious human monoclonal antibodies might lead to the better management of moderate to severe cases of AD. METHODOLOGY: The scientific literature available in databases, such as Pubmed and Clinicaltrial.gov, was searched and discussed for available clinical therapeutic information. DISCUSSION: The present review has discussed the potential immunological targets of specific monoclonal antibodies developed and approved or which are under investigation in clinical trials. CONCLUSION: The development of targeted monoclonal antibodies can improve the understanding of the role of different immunological pathways and biomarkers in AD and become the future of AD treatment.

Focus on Filgotinib in Rheumatoid Arthritis: A Trial-Based Review.

Janus kinases (JAK)/Signal Transducer and Activator of Transcription (STAT) pathway is involved in pathophysiologic cascade of a notable number of rheumatic diseases. The development of JAK inhibitors has expanded treatment choices in rheumatoid arthritis (RA) with a sustained class-effect efficacy. Filgotinib is a novel selective inhibitor of JAK1 isoform licensed for use in RA and ulcerative colitis. In this review we aim to present an analysis of filgotinib's efficacy and drug-specific safety warnings. Patients with RA with or without concomitant conventional synthetic Disease-Modifying Antirheumatic Drugs (csDMARDs) (naïve or experienced) and those who have failed biologic Disease-Modifying Antirheumatic Drugs (bDMARDs) were examined in randomised clinical trials. Filgotinib was also tested against placebo, methotrexate, or adalimumab. Long-term extension trials provide insights for up to four years of continuous filgotinib administration. Beneficial effects are depicted in both disease activity parameters and quality of life indexes in moderate or severe RA with a longitudinal efficacy. In head-to-head comparison with adalimumab, filgotinib 200 mg was non-inferior. Adverse effects alerts are marked by the elevated risk of infectious adverse effects with the exception of herpes zoster infection, which has a low incidence.

Novel JAK Inhibitors to Reduce Graft-Versus-Host Disease after Allogeneic Hematopoietic Cell Transplantation in a Preclinical Mouse Model.

Allogeneic hematopoietic cell transplantation (allo-HCT) is a highly effective, well-established treatment for patients with various hematologic malignancies and non-malignant diseases. The therapeutic benefits of allo-HCT are mediated by alloreactive T cells in donor grafts. However, there is a significant risk of graft-versus-host disease (GvHD), in which the donor T cells recognize recipient cells as foreign and attack healthy organs in addition to malignancies. We previously demonstrated that targeting JAK1/JAK2, mediators of interferon-gamma receptor (IFNGR) and IL-6 receptor signaling, in donor T cells using baricitinib and ruxolitinib results in a significant reduction in GvHD after allo-HCT. Furthermore, we showed that balanced inhibition of JAK1/JAK2 while sparing JAK3 is important for the optimal prevention of GvHD. Thus, we have generated novel JAK1/JAK2 inhibitors, termed WU derivatives, by modifying baricitinib. Our results show that WU derivatives have the potential to mitigate GvHD by upregulating regulatory T cells and immune reconstitution while reducing the frequencies of antigen-presenting cells (APCs) and CD80 expression on these APCs in our preclinical mouse model of allo-HCT. In addition, WU derivatives effectively downregulated CXCR3 and T-bet in primary murine T cells. In summary, we have generated novel JAK inhibitors that could serve as alternatives to baricitinib or ruxolitinib.

Revealing innovative JAK1 and JAK3 inhibitors: a comprehensive study utilizing QSAR, 3D-Pharmacophore screening, molecular docking, molecular dynamics, and MM/GBSA analyses.

The heterocycle compounds, with their diverse functionalities, are particularly effective in inhibiting Janus kinases (JAKs). Therefore, it is crucial to identify the correlation between their complex structures and biological activities for the development of new drugs for the treatment of rheumatoid arthritis (RA) and cancer. In this study, a diverse set of 28 heterocyclic compounds selective for JAK1 and JAK3 was employed to construct quantitative structure-activity relationship (QSAR) models using multiple linear regression (MLR). Artificial neural network (ANN) models were employed in the development of QSAR models. The robustness and stability of the models were assessed through internal and external methodologies, including the domain of applicability (DoA). The molecular descriptors incorporated into the model exhibited a satisfactory correlation with the receptor-ligand complex structures of JAKs observed in X-ray crystallography, making the model interpretable and predictive. Furthermore, pharmacophore models ADRRR and ADHRR were designed for each JAK1 and JAK3, proving effective in discriminating between active compounds and decoys. Both models demonstrated good performance in identifying new compounds, with an ROC of 0.83 for the ADRRR model and an ROC of 0.75 for the ADHRR model. Using a pharmacophore model, the most promising compounds were selected based on their strong affinity compared to the most active compounds in the studied series each JAK1 and JAK3. Notably, the pharmacokinetic, physicochemical properties, and biological activities of the selected compounds (As compounds ZINC79189223 and ZINC66252348) were found to be consistent with their therapeutic effects in RA, owing to their non-toxic, cholinergic nature, absence of P-glycoprotein, high gastrointestinal absorption, and ability to penetrate the blood-brain barrier. Furthermore, ADMET properties were assessed, and molecular dynamics and MM/GBSA analysis revealed stability in these molecules.

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.

Epstein-Barr Virus Promotes Tumorigenicity and Worsens Hodgkin Lymphoma Prognosis by Activating JAK/STAT and NF-κB Signaling Pathways.

Background: Epstein-Barr virus (EBV) is detected in 40% of patients with Hodgkin lymphoma (HL). During latency, EBV induces epigenetic alterations to the host genome and decreases the expression of pro-apoptotic proteins. The present study aimed to evaluate the expression levels of mRNA molecules and the end product of proteins for the JAK/STAT and NF-κB pathways, and their association with clinicopathological and prognostic parameters in patients with EBV-positive and -negative classical Hodgkin lymphoma (CHL). Methods: A prospective cohort study was conducted from 2017 to 2022 at the Faculty of Medicine, Zagazig University Hospital (Zagazig, Egypt). Biopsy samples of 64 patients with CHL were divided into EBV-positive and EBV-negative groups. The expression levels of mRNA molecules (JAK2, STAT1, IRF-1, PD-L1, IFN-γ, NF-κB, Bcl-xL, COX-2) and the end product of proteins (PD-L1, Bcl-xL, COX-2) were determined and compared with clinicopathological and prognostic parameters. Data were analyzed using the Chi square test and Kaplan-Meier estimate. Results: EBV-positive CHL patients were significantly associated with positive expression of mRNAs molecules (P<0.001) and the end product of proteins (P<0.001) for the JAK/STAT and NF-κB pathways, B-symptoms (P=0.022), extra-nodal involvement (P=0.017), and advanced stage of CHL (P=0.018). These patients were more susceptible to cancer progression, higher incidence of relapse (P=0.008), poor disease-free survival rate (P=0.013), poor overall survival rate (P=0.028), and higher mortality rate (P=0.015). Conclusion: Through the activation of JAK/STAT and NF-κB signaling pathways, EBV-positive CHL is associated with poor clinicopathological parameters, higher incidence of disease progression, relapse, and poor overall survival. A preprint of this manuscript is available on research square (doi: 10.21203/rs.3.rs-1857436/v1).

Janus Kinase Inhibitor Brepocitinib Rescues Myelin Phagocytosis Under Inflammatory Conditions: In Vitro Evidence from Microglia and Macrophage Cell Lines.

Central nervous system (CNS) injuries induce cell death and consequently the release of myelin and other cellular debris. Microglia as well as hematogenous macrophages actively collaborate to phagocyte them and undergo their degradation. However, myelin accumulation persists in the lesion site long after the injury with detrimental effects on axonal regeneration. This might be due to the presence of inhibitors of phagocytosis in the injury site. As we recently published that some proinflammatory stimuli, like interferon-γ (IFNγ) and lipopolysaccharide (LPS), inhibit myelin phagocytosis in macrophages, we have now studied the signaling pathways involved. A phagocytosis assay in Raw264.7 macrophages and N13 microglia cell lines with labeled myelin was developed with the pHrodo reagent that emits fluorescence in acidic cellular compartments (e.g.lysosomes). Pharmacological inhibition of Janus kinases (Jak) with Brepocitinib restored myelin phagocytosis and rescued the expression of genes related to phagocytosis, like triggering receptor expressed on myeloid cells 2 (TREM2), induced by IFNγ or LPS. In addition, while pharmacological inhibition of the signal transducer and activator of transcription 3 (STAT3) rescued myelin phagocytosis and the expression of phagocytosis related genes in the presence of LPS, it did not have any effect on IFNγ-treated cells. Our results show that Jak pathways participate in the inhibition of myelin phagocytosis by IFNγ and LPS. They also indicate that the resolution of inflammation is important for the clearance of cellular debris by macrophages and subsequent regenerative processes.

Safety of dermatologic medications in pregnancy and lactation: An Update - Part II: Lactation.

Multiple recently approved medications have been added to our treatment armamentarium for various dermatologic conditions. Herein, we have reviewed the literature, consolidated available safety data, and offered recommendations based upon available evidence as a reference guide for clinicians treating patients for dermatologic conditions during lactation.

Moderate to severe atopic dermatitis in children: focus on systemic Th2 cytokine receptor antagonists and Janus kinase inhibitors.

Atopic dermatitis (AD) is a lifelong disease that markedly impairs quality of life. AD is considered a starting point of the "atopic march," which begins at a young age and may progress to systemic allergic diseases. Moreover, it is strongly associated with comorbid allergic and inflammatory diseases including arthritis and inflammatory bowel disease. Understanding the pathogenesis of AD is essential for the development of targeted therapies. Epidermal barrier dysfunction, immune deviation toward a T helper 2 proinflammatory profile, and microbiome dysbiosis play important roles via complex interactions. The systemic involvement of type 2 inflammation, wheather acute or chronic, and whether extrinsic or intrinsic, is evident in any type of AD. Studies on AD endotypes with unique biological mechanisms have been conducted according to clinical phenotypes, such as race or age, but the endotype for each phenotype, or endophenotype, has not yet been clearly identified. Therefore, AD is still being treated according to severity rather than endotype. Infancy-onset and severe AD are known risk factors leading to atopic march. In addition, up to 40% of adult AD are cases of infancy-onset AD that persist into adulthood, and these are often accompanied by other allergic diseases. Therefore, early intervention strategies to identify high-risk infants and young children, repair an impaired skin barrier, and control systemic inflamation may improve long-term outcomes in AD patients. However, to the best of our knowledge, no study has evaluated the effectiveness of early intervention on atopic march using systemic therapy in high-risk infants. This narrative review addresses the latest knowledge of systemic treatment, including Th2 cytokine receptor antagonists and Janus kinase inhibitors, for children with moderate to severe AD that is refractory to topical treatment.

Community analysis of large-scale molecular dynamics simulations elucidated dynamics-driven allostery in tyrosine kinase 2.

TYK2 is a nonreceptor tyrosine kinase, member of the Janus kinases (JAK), with a central role in several diseases, including cancer. The JAKs' catalytic domains (KD) are highly conserved, yet the isolated TYK2-KD exhibits unique specificities. In a previous work, using molecular dynamics (MD) simulations of a catalytically impaired TYK2-KD variant (P1104A) we found that this amino acid change of its JAK-characteristic insert (αFG), acts at the dynamics level. Given that structural dynamics is key to the allosteric activation of protein kinases, in this study we applied a long-scale MD simulation and investigated an active TYK2-KD form in the presence of adenosine 5'-triphosphate and one magnesium ion that represents a dynamic and crucial step of the catalytic cycle, in other protein kinases. Community analysis of the MD trajectory shed light, for the first time, on the dynamic profile and dynamics-driven allosteric communications within the TYK2-KD during activation and revealed that αFG and amino acids P1104, P1105, and I1112 in particular, hold a pivotal role and act synergistically with a dynamically coupled communication network of amino acids serving intra-KD signaling for allosteric regulation of TYK2 activity. Corroborating our findings, most of the identified amino acids are associated with cancer-related missense/splice-site mutations of the Tyk2 gene. We propose that the conformational dynamics at this step of the catalytic cycle, coordinated by αFG, underlie TYK2-unique substrate recognition and account for its distinct specificity. In total, this work adds to knowledge towards an in-depth understanding of TYK2 activation and may be valuable towards a rational design of allosteric TYK2-specific inhibitors.

Jianpi Qutan Fang induces anti-atherosclerosis and ameliorates endothelial cell injury in high-fat diet ratsan anti-inflammatory and inhibiting Janus kinase/signal transducer and activator of transcription signaling pathway.

OBJECTIVE: To investiage the possible mechanism underlying the effect of the Jianpi Qutan Fang (, JPQT) on Atherosclerosis (AS) which is the main pathological process of most cardiovascular diseases that affect millions of adults worldwide. METHODS: In the present study, rats were fed with a high-fat-diet (HFD) with vitamin D3 for 16 weeks and were orally administered atorvastatin treatment and different doses of JPQT. Histopathological changes and ultrastructural changes in the aorta were evaluated through hematoxylin-eosin staining and transmission electron microscopy (TEM), respectively. Suppressor of cytokine signaling 1 (SOCS1)/Janus kinase 1 (JAK1)/ signal transducer and activator of transcription 1 (STAT1) signaling pathways were detected through Western blotting. RESULTS: JPQT treatment decreased the lipid levels of triglyceride, low-density lipoprotein, and cholesterol, the inflammatory cytokine levels of interleukin 1 beta (IL-1ß), IL-6 and IL-8 in rat serum, but increased high-density lipoprotein and IL-10 serum levels. JPQT treatment ameliorated pathological changes in the aorta of AS model rats. Moreover, JPQT upregulated SOCS1 protein expression and down-regulated phosphorylated protein expression levels of p-JAK1 and p-STAT1. CONCLUSION: These results suggest that JPQT induces anti-atherosclerosis effects through anti-inflammatory and inhibiting JAK/STAT signaling pathways in HFD fed rats.

Inhibition of JAK-STAT pathway corrects salivary gland inflammation and interferon driven immune activation in Sjögren's Disease.

Objectives: Inflammatory cytokines that signal through the JAK- STAT pathway, especially interferons (IFNs), are implicated in Sjögren's Disease (SjD). Although inhibition of JAKs is effective in other autoimmune diseases, a systematic investigation of IFN-JAK-STAT signaling and effect of JAK inhibitor (JAKi) therapy in SjD-affected human tissues has not been reported. Methods: Human minor salivary glands (MSGs) and peripheral blood mononuclear cells (PBMCs) were investigated using bulk or single cell (sc) RNA sequencing (RNAseq), immunofluorescence microscopy (IF), and flow cytometry. Ex vivo culture assays on PBMCs and primary salivary gland epithelial cell (pSGEC) lines were performed to model changes in target tissues before and after JAKi. Results: RNAseq and IF showed activated JAK-STAT pathway in SjD MSGs. Elevated IFN-stimulated gene (ISGs) expression associated with clinical variables (e.g., focus scores, anti-SSA positivity). scRNAseq of MSGs exhibited cell-type specific upregulation of JAK-STAT and ISGs; PBMCs showed similar trends, including markedly upregulated ISGs in monocytes. Ex vivo studies showed elevated basal pSTAT levels in SjD MSGs and PBMCs that were corrected with JAKi. SjD-derived pSGECs exhibited higher basal ISG expressions and exaggerated responses to IFNß, which were normalized by JAKi without cytotoxicity. Conclusions: SjD patients' tissues exhibit increased expression of ISGs and activation of the JAK-STAT pathway in a cell type-dependent manner. JAKi normalizes this aberrant signaling at the tissue level and in PBMCs, suggesting a putative viable therapy for SjD, targeting both glandular and extraglandular symptoms. Predicated on these data, a Phase Ib/IIa randomized controlled trial to treat SjD with tofacitinib was initiated.

Retrospective comparative study of the efficacy of JAK inhibitor (tofacitinib) in the treatment of systemic sclerosis-associated interstitial lung disease.

The oral Janus kinases inhibitor (JAKi) has improved the management of skin manifestations in systemic sclerosis (SSc), and our study aimed to explore the efficacy of non-selective JAKi tofacitinib in ameliorating interstitial lung disease (ILD) in the patients with SSc. The hospitalization data of the SSc-ILD patients from April 2019 to April 2021 were collected, and the changes of pulmonary function and the radiological findings in pulmonary high-resolution CT (HRCT) from the 9 patients who received tofacitinib for at least 6 months and a matched group of 35 SSc-ILD patients treated with conventional immunosuppressants or glucocorticoids, were compared and analyzed. There were no significant differences in demographic data and clinical characteristics between the tofacitinib-treated group (tofa-group) and the matched group. However, in the tofa-group, the changes in serum lactate dehydrogenase (LDH) concentration and serum interleukin-6 levels were significantly lower than those in the matched group. Moreover, the tofa-group showed amelioration in decreased diffusing capacity of the lung for carbon monoxide (DLCO) (62.05 ± 9.47 vs. 66.61 ± 12.39, p = 0.046), reductions in ground-glass attenuation involvement (1.00 ± 0.86 vs. 0.33 ± 0.50, p = 0.024) and irregular pleural thickening (1.33 ± 0.50 vs. 0.67 ± 0.51, p = 0.004) in pulmonary HRCTs, alleviated modified Rodnan skin score (mRSS) of skin sclerosis (9.22 ± 3.81 vs. 7.11 ± 3.92, p = 0.048), and reduced HRCT scores of pulmonary fibrosis (15.00 ± 3.87 vs. 12.66 ± 4.92, p = 0.009). Logistic regression analysis showed that the involvement of ground-glass attenuation (OR 11.43) and the add-on therapy of tofacitinib (OR 9.98) were the relevant factors in the amelioration of HRCT. Our results indicate that the use of JAKi (tofacitinib) may be relevant to significant improvement of the sclerosis and early radiological abnormalities in SSc-ILD patients. Further studies are needed to confirm these findings and to explore its efficacy more precisely. Key Points • The currently available therapies for SSc-ILD have limited therapeutic benefits. • The add-on therapy of the oral JAK inhibitor is available in the real world. • The tofacitinib was promising in the improvement of the sclerosis and early radiological abnormalities in SSc-ILD patients.

In silico molecular docking analysis of three molecules isolated from Litsea guatemalensis Mez on anti-inflammatory receptors.

BACKGROUND: The Litsea genus has four native species from Mesoamerica. Litsea guatemalensis Mez. is a native tree, traditionally used as a condiment and herbal medicine in the region. It has demonstrated antimicrobial, aromatic, anti-inflammatory and antioxidant activity. Bioactive fractionation attributed the anti-inflammatory and anti-hyperalgesic activities to pinocembrin, scopoletin, and 5,7,3´4´-tetrahydroxy-isoflavone. In silico analysis, these molecules were analyzed on receptors involved in the anti-inflammatory process to determine which pathways they interact. OBJECTIVE: To analyze and evaluate 5,7,3',4'-tetrahydroxyisoflavone, pinocembrin, and scopoletin using the in silico analysis against selected receptors involved in the inflammatory pathway. METHOD: Known receptors involved in the anti-inflammatory process found as protein-ligand complex in the Protein Data Bank (PDB) were used as references for each receptor and compared with the molecules of interest. The GOLD-ChemScore function, provided by the software, was used to rank the complexes and visually inspect the overlap between the reference ligand and the poses of the studied metabolites. RESULTS: 53 proteins were evaluated, each one in five conformations minimized by molecular dynamics. The scores obtained for dihydroorotate dehydrogenase were greater than 80 for the three molecules of interest, scores for cyclooxygenase 1 and glucocorticoid receptor were greater than 50, and identified residues with interaction in binding sites overlap with the reference ligands in these receptors. CONCLUSION: The three molecules involved in the anti-inflammatory process of L. guatemalensis show in silico high affinity to the enzyme dihydroorotate dehydrogenase, glucocorticoid receptors and cyclooxygenase-1.

New small molecules in dermatology: for the autoimmunity, inflammation and beyond.

OBJECTIVE AND DESIGN: The discovery of new inflammatory pathways and the mechanism of action of inflammatory, autoimmune, genetic, and neoplastic diseases led to the development of immunologically driven drugs. We aimed to perform a narrative review regarding the rising of a new class of drugs capable of blocking important and specific intracellular signals in the maintenance of these pathologies: the small molecules. MATERIALS/METHODS: A total of 114 scientific papers were enrolled in this narrative review. RESULTS: We describe in detail the families of protein kinases-Janus Kinase (JAK), Src kinase, Syk tyrosine kinase, Mitogen-Activated Protein Kinase (MAPK), and Bruton Tyrosine Kinase (BTK)-their physiologic function and new drugs that block these pathways of intracellular signaling. We also detail the involved cytokines and the main metabolic and clinical implications of these new medications in the field of dermatology. CONCLUSIONS: Despite having lower specificity compared to specific immunobiological therapies, these new drugs are effective in a wide variety of dermatological diseases, especially diseases that had few therapeutic options, such as psoriasis, psoriatic arthritis, atopic dermatitis, alopecia areata, and vitiligo.

Paradoxical activation of chronic lymphocytic leukemia cells by ruxolitinib in vitro and in vivo.

Introduction: Chronic lymphocytic leukemia (CLL) is characterized by an aberrant cytokine network that can support tumor growth by triggering janus kinase (JAK)/STAT pathways. Targeting cytokine-signaling should then be a rational therapeutic strategy but the JAK inhibitor ruxolitinib failed to control and seemingly accelerated the disease in clinical trials. Methods: The effect of ruxolitinib on primary human CLL cells was studied in vitro and in vivo. Results: Ruxolitinib increased phosphorylation of IRAK4, an important toll-like receptor (TLR)- signaling intermediate, in circulating CLL cells in vitro. It also enhanced p38 and NFKB1 phosphorylation while lowering STAT3 phosphorylation in CLL cells activated with TLR-7/8 agonists and IL-2. Among the cytokines made by activated CLL cells, high levels of IL-10 contributed strongly to STAT3 phosphorylation and inhibited TLR7 activity. Ruxolitinib limited TLR-mediated IL10 transcription and markedly reduced IL-10 production in vitro. It also decreased blood levels of IL-10 while increasing TNFα along with phospho-p38 expression and gene sets associated with TLR-activation in CLL cells in vivo. The bruton's tyrosine kinase inhibitor ibrutinib decreased IL-10 production in vitro but, in contrast to ruxolitinib, blocked initial IL10 transcription induced by TLR-signaling in vitro, decreased TNFα production, and deactivates CLL cells in vivo. Discussion: These findings suggest the possible benefits of inhibiting growth factors with JAK inhibitors in CLL are outweighed by negative effects on potential tumor suppressors such as IL-10 that allow unrestrained activation of NFκB by drivers such as TLRs. Specific inhibition of growth-promoting cytokines with blocking antibodies or infusing suppressive cytokines like IL-10 might be better strategies to manipulate cytokines in CLL.

[Activation of JAK/STAT in ovarian high-grade serous cancers and its prognostic significance].

OBJECTIVE: The activation of Janus kinase (JAK) and signal transducers and activators of transcription (STAT) plays an important role in the prognosis and targeted therapy of ovarian high-grade serous carcinoma (HGSC). Utilizing simple and practicable technique, this study aimed to evaluate the activation of JAK/STAT signaling pathway in ovarian HGSC patients, and investigated the correlation between the activation of JAK/STAT signaling pathway and the prognosis of the HGSC patients. METHODS: We performed immunohistochemistry of phosphorylated STAT3 (pSTAT3) and phosphorylated STAT5 (pSTAT5) on paraffin imbedded slides of 73 ovarian HGSC patients, and evaluated the expression level and range of both markers. According to the grading score of the immunostaining of pSTAT3 and pSTAT5, we divided the 73 ovarian HGSC cases into STAT3 low/high expression and STAT5 low/high expression groups, and analyzed the prognosis of the patients in different groups, in order to explore the relationship between the expression of pSTAT3 and pSTAT5 proteins and the prognosis of the HGSC patients. RESULTS: Some of the ovarian HGSC cases showed high expression of pSTAT3 and pSTAT5 protein level, which was related to the poorer prognosis of the HGSC patients. There was a significant difference in the expression level of pSTAT3 and pSTAT5 between the patients with better prognosis (survival time ≥3 years) and poorer prognosis (survival time < 3 years). The patients with higher protein expression of pSTAT3, pSTAT5 or both markers might have poorer prognosis, with significant shorter progression-free survival time and overall survival time (P < 0.001). CONCLUSION: Immunostaining of pSTAT3 and pSTAT5 proteins might be helpful to evaluate and predict the prognosis of the ovarian HGSC patients, and to identify the patients who might have higher chances to respond to the STAT inhibitors and anti-angiogenesis therapy.

Upadacitinib for the treatment of psoriatic arthritis.

Psoriatic arthritis is a chronic systemic inflammatory disease that presents with a variable clinical course and is typically associated with joint inflammation, together with cutaneous psoriasis. In recent decades, knowledge of the pathogenesis of psoriatic arthritis has advanced considerably and has allowed for development of new highly effective therapies, transforming the treatment landscape. Upadacitinib is a Janus kinase inhibitor (JAK) that is orally reversible with high selectivity for JAK1 and its signal transduction molecules. The results obtained in the phase III clinical trials (SELECT-PsA 1 and SELEC-PsA 2) demonstrated that upadacitinib was highly effective over placebo and non-inferior to adalimumab in several important domains of the disease. Improvements were observed in dactylitis, enthesitis and spondylitis as well as in physical function, pain, fatigue and overall quality of life. The safety profile of these results resembled that of adalimumab, apart from a slightly higher rate of herpes zoster infection, an increase of creatine kinase and an incidence of lymphopenia. However, none of these events was considered a serious adverse advent. Additionally, another analysis demonstrated that combining upadacitinib with methotrexate was associated with a similar efficacy to upadacitinib in monotherapy, both for patients that are naive to biologics treatment and for those previously treated with biologics. Therefore, upadacitinib is a new option for the treatment of psoriatic arthritis, presenting a series of beneficial characteristics. At this stage, it is important to collect long-term data to confirm the efficacy and safety profiles shown in clinical trials.