JAK/STAT disruption induces immuno-deficiency: Rationale for the development of JAK inhibitors as immunosuppressive drugs

Design and synthesis of highly selective Janus kinase 3 covalent inhibitors for the treatment of rheumatoid arthritis

Selective inhibition of Janus kinase 3 (JAK3) is a promising strategy for the treatment of autoimmune diseases. Based on the discovery of a hydrophobic pocket unutilized between the lead compound RB1 and the JAK3 protein, a series of covalent JAK3 inhibitors were prepared by introducing various aromatic fragments to RB1. Among them, J1b (JAK3 IC50 = 7.2 nM, other JAKs IC50 > 1000 nM) stood out because of its low toxicity (MTD > 2 g/kg) and superior anti-inflammatory activity in Institute of Cancer Research mice. Moreover, the acceptable bioavailability (F% = 31.69%) ensured that J1b displayed excellent immune regulation in collagen-induced arthritis mice, whose joints in the high-dose group were almost recovered to a normal state. Given its clear kinase selectivity (Bmx IC50 = 539.9 nM, other Cys909 kinases IC50 > 1000 nM), J1b was nominated as a highly selective JAK3 covalent inhibitor, which could be used to safely treat arthritis and other autoimmune diseases.

Cloning and functional characterization of novel human neutralizing anti-interferon-alpha and anti-interferon-beta antibodies

Type I interferons (IFNs) play a pivotal role in immune response modulation, yet dysregulation is implicated in various disorders. Therefore, it is crucial to develop tools that facilitate the understanding of their mechanism of action and enable the development of more effective anti-IFN therapeutic strategies. In this study, we isolated, cloned, and characterized anti-IFN-α and anti-IFN-β antibodies (Abs) from peripheral blood mononuclear cells of individuals treated with IFN-α or IFN-β, harboring confirmed neutralizing Abs. Clones AH07856 and AH07857 were identified as neutralizing anti-IFN-α-specific with inhibition against IFN-α2a, -α2b, and -αK subtypes. Clones AH07859 and AH07866 were identified as neutralizing anti-IFN-β1a-specific signaling, and able to block Lipopolysaccharide or S100 calcium binding protein A14-induced IFN-β signaling effects. Cloned Abs bind rhesus but not murine IFNs. The specificity of inhibition between IFN-α and IFN-β suggests potential for diverse research and clinical applications.

Engineering immune response to regulate cardiovascular disease and cancer

Cardiovascular disease (CVD) and cancer are major contributors to global morbidity and mortality. This book chapter delves into the intricate relationship between the immune system and the pathogenesis of both cardiovascular and cancer diseases, exploring the roles of innate and adaptive immunities, immune regulation, and immunotherapy in these complex conditions. The innate immune system acts as the first line of defense against tissue damage and infection, with a significant impact on the initiation and progression of CVD and cancer. Endothelial dysfunction, a hallmark in CVD, shares commonalities with the tumor microenvironment in cancer, emphasizing the parallel involvement of the immune system in both conditions. The adaptive immune system, particularly T cells, contributes to prolonged inflammation in both CVD and cancer. Regulatory T cells and the intricate balance between different T cell subtypes influence disease progression, wound healing, and the outcomes of ischemic injury and cancer immunosurveillance. Dysregulation of immune homeostasis can lead to chronic inflammation, contributing to the development and progression of both CVD and cancer. Thus, immunotherapy emerged as a promising avenue for preventing and managing these diseases, with strategies targeting immune cell modulation, cytokine manipulation, immune checkpoint blockade, and tolerance induction. The impact of gut microbiota on CVD and cancer too is explored in this chapter, highlighting the role of gut leakiness, microbial metabolites, and the potential for microbiome-based interventions in cardiovascular and cancer immunotherapies. In conclusion, immunomodulatory strategies and immunotherapy hold promise in reshaping the landscape of cardiovascular and cancer health. Additionally, harnessing the gut microbiota for immune modulation presents a novel approach to prevent and manage these complex diseases, emphasizing the importance of personalized and precision medicine in healthcare. Ongoing research and clinical trials are expected to further elucidate the complex immunological underpinnings of CVD and cancer thereby refining these innovative approaches.

MicroRNAs: Key modulators of inflammation-associated diseases

Inflammation is a multifaceted biological and pathophysiological response to injuries, infections, toxins, and inflammatory mechanisms that plays a central role in the progression of various diseases. MicroRNAs (miRNAs) are tiny, 19-25 nucleotides long, non-coding RNAs that regulate gene expression via post-transcriptional repression. In this review, we highlight the recent findings related to the significant roles of miRNAs in regulating various inflammatory cascades and immunological processes in the context of many lifestyle-related diseases such as diabetes, cardiovascular diseases, cancer, etc. We also converse on how miRNAs can have a dual impact on inflammatory responses, suggesting that regulation of their functions for therapeutic purposes may be disease-specific.

SOCS-JAK-STAT inhibitors and SOCS mimetics as treatment options for autoimmune uveitis, psoriasis, lupus, and autoimmune encephalitis

Autoimmune diseases arise from atypical immune responses that attack self-tissue epitopes, and their development is intricately connected to the disruption of the JAK-STAT signaling pathway, where SOCS proteins play crucial roles. Conditions such as autoimmune uveitis, psoriasis, lupus, and autoimmune encephalitis exhibit immune system dysfunctions associated with JAK-STAT signaling dysregulation. Emerging therapeutic strategies utilize JAK-STAT inhibitors and SOCS mimetics to modulate immune responses and alleviate autoimmune manifestations. Although more research and clinical studies are required to assess their effectiveness, safety profiles, and potential for personalized therapeutic approaches in autoimmune conditions, JAK-STAT inhibitors and SOCS mimetics show promise as potential treatment options. This review explores the action, effectiveness, safety profiles, and future prospects of JAK inhibitors and SOCS mimetics as therapeutic agents for psoriasis, autoimmune uveitis, systemic lupus erythematosus, and autoimmune encephalitis. The findings underscore the importance of investigating these targeted therapies to advance treatment options for individuals suffering from autoimmune diseases.

Double-edged sword of JAK/STAT signaling pathway in viral infections: novel insights into virotherapy

The Janus kinase/signal transducer and activator of transcription (JAK/STAT) is an intricate signaling cascade composed of various cytokines, interferons (IFN, growth factors, and other molecules. This pathway provides a delicate mechanism through which extracellular factors adjust gene expression, thereby acting as a substantial basis for environmental signals to influence cell growth and differentiation. The interactions between the JAK/STAT cascade and antiviral IFNs are critical to the host's immune response against viral microorganisms. Recently, with the emergence of therapeutic classes that target JAKs, the significance of this  cascade has been recognized in an unprecedented way. Despite the functions of the JAK/STAT pathway in adjusting immune responses against viral pathogens, a vast body of evidence proposes the role of this cascade in the replication and pathogenesis of viral pathogens. In this article, we review the structure of the JAK/STAT signaling cascade and its role in immuno-inflammatory responses. We also highlight the paradoxical effects of this pathway in the pathogenesis of viral infections. Video Abstract.

Abrocitinib for the Treatment of Moderate-to-Severe Atopic Dermatitis

BACKGROUND

Atopic dermatitis (AD) is ranked as the third most prevalent skin condition with a worldwide prevalence of 2.4%. Atopic dermatitis is a common form of eczema. It develops in infancy or childhood and continues into adulthood with symptoms ranging from mild to severe. Pruritis and inflammation are the hallmark symptoms of AD.

MECHANISM OF ACTION, PHARMACODYNAMICS, AND PHARMACOKINETICS

Abrocitinib is a JAK1 selective inhibitor; inhibition results in a decreased interleukin (IL) 4 activation and decreased pruritis in a patient with AD. Abrocitinib is hepatically metabolized by multiple cytochrome P450 enzymes, and dose modification may be required when administered with concurrent medications.

CLINICAL TRIALS

At least 6 JAK1 Atopic Dermatitis Efficacy and Safety (JADE) trials were conducted evaluating Investigator's Global Assessment and Eczema Area and Severity Index score for efficacy. All JADE trials showed abrocitinib 100 mg and 200 mg doses efficacious when compared with placebo. Common adverse reactions were related to gastrointestinal disturbances, headache, and acne. Serious adverse reactions to assess risk for include serious infections, malignancy, major adverse cardiovascular events, and venous thromboembolisms.

THERAPEUTIC ADVANCE

Abrocitinib provides a valuable treatment option for patients with moderate-to-severe AD unresponsive to other therapies for those candidates without a high risk for significant adverse reaction associated with its use.

Tofacitinib reduces acute lung injury and improves survival in a rat model of sepsis by inhibiting the JAK-STAT/NF-κB pathway

Acute lung injury is a major cause of death in sepsis. Tofacitinib (TOFA), a JAK inhibitor, has anti-inflammatory activity in autoimmune diseases, but its role in acute lung injury in sepsis remains unclear. The purpose of this study is to establish a septic rat model by cecal ligation and perforation, and to evaluate the effect of tofacitinib on the survival rate of septic rat model and its role in acute lung injury in septic rats and the possible mechanism of action. In this study, TOFA (1 mg/kg, 3 mg/kg, 10 mg/kg) was used to observe the survival rate of septic rats. It was found that TOFA (10 mg/kg) significantly improved the survival rate of septic rats. We selected TOFA (10 mg/kg) and focused on the protective effect of TOFA on acute lung injury. The results confirmed that TOFA significantly inhibited the expression of TNF-α, IL-1β, IL-6 and IFN-γ inflammatory factors, reduced the W/D weight ratio of septic lung tissue, and significantly improved lung histopathological damage. These results may be related to the inhibitory effect of TOFA on JAK-STAT/NF-κ B signaling pathway. In conclusion, for the first time, we found that TOFA has a protective effect against sepsis-induced acute lung injury, and it may be a promising drug for the treatment of acute lung injury in sepsis.

Skin cancers under Janus kinase inhibitors: A World Health Organization drug safety database analysis

BACKGROUND

Janus kinase (JAK) inhibitors are targeted therapies with a potential imunomodulatory and anti-inflammatory effect, indicated in various dysimmune pathologies. Skin cancers have been reported to occur in patients treated with JAK inhibitors. However, drug safety in clinical trials did not confirm that risk, but these studies are performed on controlled population and in a limited time of follow up.

OBJECTIVES

The aim of this study is to evaluate in real life condition if a disproportionality signal exists between JAK inhibitors treatment and skin cancers.

METHODS

We performed cases/non cases analysis in VigiBase® (the World Health Organization international database of suspected adverse drug reaction) using information component to search for a disproportionality signal of skin cancers from JAK inhibitor. We extracted all reports of skin cancers from the French Pharmacovigilance database occurring since 1978 up to 31^st December 2019 for the three existing JAK inhibitors on market: ruxolitinib, tofacitinib and baricitinib. Only melanoma, squamous cell carcinoma and Merkel cell carcinoma were analyzed, according to the pathophysiology of these cancers and their link with immunosuppression.

RESULTS

A disproportionality signal was found positive for squamous cell carcinoma with ruxolitinib (IC025=3.92) and tofacitinib (IC025=0.82), for melanoma with ruxolitinib (IC025=0.81) and tofacitinib (IC025=0.74), and Merkel cell carcinoma with ruxolitinib (IC025=4) and tofactinib (IC025=1.01) and only for Merkel cell carcinoma with baricitinib (IC025=0.53). Moreover, Merkel cell carcinoma, a very rare skin cancer more prevalent in immunodepressed patients was particularly represented in our sample and was associated with a significant disproportionality signal with all the studied JAK inhibitors.

CONCLUSION

Our study shows that JAK inhibitors could be associated with an extra risk to develop skin cancers. Could an anti-viral or immunovigilance disruption mechanism brought by JAK inhibitors explain an over-risk with Merkel cell carcinoma, which were notably represented in our sample? Considering pharmacovigilance method limitations, further pharmacoepidemiological studies are required to assess a causal link between JAK inhibitors treatment and skin cancers development.

Treatment with a JAK1/2 inhibitor ameliorates murine autoimmune cholangitis induced by IFN overexpression

The interferon (IFN) signaling pathways are major immunological checkpoints with clinical significance in the pathogenesis of autoimmunity. We have generated a unique murine model named ARE-Del, with chronic overexpression of IFNγ, by altering IFNγ metabolism. Importantly, these mice develop an immunologic and clinical profile similar to patients with primary biliary cholangitis, including high titers of autoantibodies and portal inflammation. We hypothesized that the downregulation of IFN signaling pathways with a JAK1/2 inhibitor would inhibit the development and progression of cholangitis. To study this hypothesis, ARE-Del+/- mice were treated with the JAK1/2 inhibitor ruxolitinib and serially studied. JAK inhibition resulted in a significant reduction in portal inflammation and bile duct damage, associated with a significant reduction in splenic and hepatic CD4+ T cells and CD8+ T cells. Functionally, ruxolitinib inhibited the secretion of the proinflammatory cytokines IFNγ and TNF from splenic CD4+ T cells. Additionally, ruxolitinib treatment also decreased the frequencies of germinal center B (GC B) cells and T follicular helper (Tfh) cells and led to lower serological AMA levels. Of note, liver and peritoneal macrophages were sharply decreased and polarized from M1 to M2 with a higher level of IRF4 expression after ruxolitinib treatment. Mechanistically, ruxolitinib inhibited the secretion of IL-6, TNF and MCP1 and the expression of STAT1 but promoted the expression of STAT6 in macrophages in vitro, indicating that M1 macrophage polarization to M2 occurred through activation of the STAT6-IRF4 pathway. Our data highlight the significance, both immunologically and clinically, of the JAK/STAT signaling pathway in autoimmune cholangitis.

Baricitinib: The First Jak Inhibitor Approved in Europe for the Treatment of Moderate to Severe Atopic Dermatitis in Adult Patients

Background: Atopic dermatitis (AD) is an inflammatory skin disease characterized by a wide phenotypic variety with a very complex pathophysiological mechanism that has led to the identification of new therapeutic targets, such as janus kinasis (JAK) inhibitors. Objectives: To evaluate the efficacy and safety of baricitinib, the first JAK 1 and 2 inhibitor approved in Europe for the treatment of adult patients with moderate-to-severe AD. Methods: The efficacy and safety data available from the Phase III studies belonging to the BREEZE AD program are presented. Results: Results from BREEZE-AD1, AD2, AD4, and AD7 showed the efficacy of Baricitib 4 mg, administered orally, once daily, as monotherapy or in combination with topical corticosteroid (TCS), with a significant proportion of patients achieving primary endpoints IGA 0-1 (16.4% vs. 4.8%; 13.8% vs. 4.5%; 21.7% vs. 9.7%; 30.6% vs. 14.7%) and EASI75 (24.8% vs. 8.8%; 21.1% vs. 6.1%; 31.5% vs. 17.2%; 47.7% vs. 22.9%) at week 16 (W16) compared to placebo, respectively. Baricitinib showed rapid improvement in symptoms, starting from week 1 of treatment at 4 mg dosage, with a good safety profile. Nasopharyngitis, upper respiratory tract infections (URIs), creatine phosphokinase (CPK) elevations, and headache were the most frequently reported adverse events. Conclusions: Following the efficacy and safety data on W 16 from the phase III BREEZE-AD studies, baricitinib has recently been approved in Europe for the treatment of moderate to severe AD in adult patients. Further data to evaluate long-term efficacy and safety in a real-life setting are needed.

Bridging Radiotherapy to Immunotherapy: The IFN-JAK-STAT Axis

The unprecedented successes of immunotherapies (IOs) including immune checkpoint blockers (ICBs) and adoptive T-cell therapy (ACT) in patients with late-stage cancer provide proof-of-principle evidence that harnessing the immune system, in particular T cells, can be an effective approach to eradicate cancer. This instills strong interests in understanding the immunomodulatory effects of radiotherapy (RT), an area that was actually investigated more than a century ago but had been largely ignored for many decades. With the "newly" discovered immunogenic responses from RT, numerous endeavors have been undertaken to combine RT with IOs, in order to bolster anti-tumor immunity. However, the underlying mechanisms are not well defined, which is a subject of much investigation. We therefore conducted a systematic literature search on the molecular underpinnings of RT-induced immunomodulation and IOs, which identified the IFN-JAK-STAT pathway as a major regulator. Our further analysis of relevant studies revealed that the signaling strength and duration of this pathway in response to RT and IOs may determine eventual immunological outcomes. We propose that strategic targeting of this axis can boost the immunostimulatory effects of RT and radiosensitizing effects of IOs, thereby promoting the efficacy of combination therapy of RT and IOs.

Targeting STAT3: A crucial modulator of sepsis

Signal transducer and activator of transcription 3 (STAT3) is a cellular signal transcription factor that has recently attracted a great deal of attention. It can trigger a variety of genes transcription in response to cytokines and growth factors stimulation, which plays an important role in many cellular biological processes involved in anti/proinflammatory responses. Sepsis is a life-threatening organ dysfunction resulting from dysregulated host responses to infection. As a converging point of multiple inflammatory responses pathways, accumulating studies have presented the elaborate network of STAT3 in sepsis pathophysiology; these results generally indicate a promising therapeutic application for targeting STAT3 in the treatment of sepsis. In the present review, we evaluated the published literature describing the use of STAT3 in the treatment of experimental and clinical sepsis. The information presented here may be useful for the design of future studies and may highlight the potential of STAT3 as a future biomarker and therapeutic target for sepsis.

Emerging systemic JAK inhibitors in the treatment of atopic dermatitis: a review of abrocitinib, baricitinib, and upadacitinib

The Janus kinases (JAK) are a group of molecules, composed of JAK1, JAK2, JAK3, and tyrosine kinase 2 (TYK2), which are key components within the JAK–signal transducers and activators of transcription pathway, where cytokine receptor signaling takes place. These molecules play a foundational role in the underlying pathogenesis of multiple immune-related conditions such as atopic dermatitis (AD), rheumatoid arthritis, psoriatic arthritis, inflammatory bowel disease, and others. Thus far, JAK inhibitors for inflammatory conditions have only been marketed for the treatment of rheumatoid arthritis and psoriatic arthritis, but ongoing phase II and phase III clinical trials for other immune-mediated diseases, such as AD, have also shown promising results. This review summarizes the clinical data available from various trials and reports on the safety and efficacy of abrocitinib, baricitinib, and upadacitinib, the three oral systemic JAK inhibitors used in the treatment of AD. The safety and efficacy of JAK inhibitors for the treatment of AD are emerging in the literature. It is important that dermatologists are aware of any potential adverse events or risks associated with the use of JAK inhibitors in order to promote a higher standard of treatment and quality of living.

Upregulation of MYBL2 independently predicts a poorer prognosis in patients with clear cell renal cell carcinoma

MYB protooncogene-like 2 (MYBL2) is a transcription factor that is upregulated and significantly associated with various human cancer types. However, the potential role of MYBL2 in clear cell renal cell carcinoma (ccRCC) is yet to be elucidated. Therefore, the expression and biological functions of MYBL2 in ccRCC were assessed in the current study using The Cancer Genome Atlas (TCGA). A Wilcoxon signed-rank test was performed to compare MYBL2 expression between ccRCC and normal tissues. Moreover, the association between MYBL2 expression and various clinicopathological factors was estimated using both the Wilcoxon signed-rank test and logistic regression. The differences in prognosis between patients with high- and low-MYBL2 expression were analyzed via the Kaplan-Meier method and Cox regression analysis. Finally, gene set enrichment analysis (GSEA) was performed to investigate the biofunctions of MYBL2 in ccRCC. It was revealed that MYBL2 was upregulated in ccRCC, and that the MYBL2 high-expression phenotype was significantly associated with sex, a high histological grade, an advanced clinical stage, tumor stage, lymph node metastasis, distant metastasis and poor overall survival (OS). It was also revealed, via the Cox regression analysis, that the upregulation of MYBL2 expression was able to independently predict a poor prognosis in patients with ccRCC. GSEA indicated that the intestinal immune network for IgA production, primary immunodeficiency, the janus kinase (JAK)-signal transducer and activator of transcription (STAT) signaling pathway, the cytosolic DNA-sensing pathway, the p53 signaling pathway and the chemokine signaling pathway were all enriched in the high-MYBL2 expression datasets. In conclusion, the present findings indicate that MYBL2 may be used as an independent prognostic factor in patients with ccRCC.

JAK-STAT Signaling: A Double-Edged Sword of Immune Regulation and Cancer Progression

Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling mediates almost all immune regulatory processes, including those that are involved in tumor cell recognition and tumor-driven immune escape. Antitumor immune responses are largely driven by STAT1 and STAT2 induction of type I and II interferons (IFNs) and the downstream programs IFNs potentiate. Conversely, STAT3 has been widely linked to cancer cell survival, immunosuppression, and sustained inflammation in the tumor microenvironment. The discovery of JAK-STAT cross-regulatory mechanisms, post-translational control, and non-canonical signal transduction has added a new level of complexity to JAK-STAT governance over tumor initiation and progression. Endeavors to better understand the vast effects of JAK-STAT signaling on antitumor immunity have unearthed a wide range of targets, including oncogenes, miRNAs, and other co-regulatory factors, which direct specific phenotypical outcomes subsequent to JAK-STAT stimulation. Yet, the rapidly expanding field of therapeutic developments aimed to resolve JAK-STAT aberrations commonly reported in a multitude of cancers has been marred by off-target effects. Here, we discuss JAK-STAT biology in the context of immunity and cancer, the consequences of pathway perturbations and current therapeutic interventions, to provide insight and consideration for future targeting innovations.

Effect of lncRNA HULC knockdown on rat secreting pituitary adenoma GH3 cells

Pituitary adenoma is one of the most common tumors in the neuroendocrine system. This study investigated the effects of long non-coding RNAs (lncRNAs) highly up-regulated in liver cancer (HULC) on rat secreting pituitary adenoma GH3 cell viability, migration, invasion, apoptosis, and hormone secretion, as well as the underlying potential mechanisms. Cell transfection and qRT-PCR were used to change and measure the expression levels of HULC, miR-130b, and FOXM1. Cell viability, migration, invasion, and apoptosis were assessed using trypan blue staining assay, MTT assay, two-chamber transwell assay, Guava Nexin assay, and western blotting. The concentrations of prolactin (PRL) and growth hormone (GH) in culture supernatant of GH3 cells were assessed using ELISA. The targeting relationship between miR-130b and FOXM1 was verified using dual luciferase activity. Finally, the expression levels of key factors involved in PI3K/AKT/mTOR and JAK1/STAT3 pathways were evaluated using western blotting. We found that HULC was highly expressed in GH3 cells. Overexpression of HULC promoted GH3 cell viability, migration, invasion, PRL and GH secretion, as well as activated PI3K/AKT/mTOR and JAK1/STAT3 pathways. Knockdown of HULC had opposite effects and induced cell apoptosis. HULC negatively regulated the expression of miR-130b, and miR-130b participated in the effects of HULC on GH3 cells. FOXM1 was a target gene of miR-130b, which was involved in the regulation of GH3 cell viability, migration, invasion, and apoptosis, as well as PI3K/AKT/mTOR and JAK1/STAT3 pathways. In conclusion, HULC tumor-promoting roles in secreting pituitary adenoma might be via down-regulating miR-130b, up-regulating FOXM1, and activating PI3K/AKT/mTOR and JAK1/STAT3 pathways.

Are peptides a solution for the treatment of hyperactivated JAK3 pathways?

While the inactivation mutations that eliminate JAK3 function lead to the immunological disorders such as severe combined immunodeficiency, activation mutations, causing constitutive JAK3 signaling, are known to trigger various types of cancer or are responsible for autoimmune diseases, such as rheumatoid arthritis, psoriasis, or inflammatory bowel diseases. Treatment of hyperactivated JAK3 is still an obstacle, due to different sensibility of mutation types to conventional drugs and unwanted side effects, because these drugs are not absolutely specific for JAK3, thus inhibiting other members of the JAK family, too. Lack of information, in which way sole inhibition of JAK3 is necessary for elimination of the disease, calls for the development of isoform-specific JAK3 inhibitors. Beside this strategy, up to date peptides are a rising alternative as chemo- or immunotherapeutics, but still sparsely represented in drug development and clinical trials. Beyond a possible direct inhibition function, crossing the cancer cell membrane and interfering in disease-causing pathways or triggering apoptosis, peptides could be used in future as adjunct remedies to potentialize traditional therapy and preserve non-affected cells. To discuss such feasible topics, this review deals with the knowledge about the structure-function of JAK3 and the actual state-of-the-art of isoform-specific inhibitor development, as well as the function of currently approved drugs or those currently being tested in clinical trials. Furthermore, several strategies for the application of peptide-based drugs for cancer therapy and the physicochemical and structural relations to peptide efficacy are discussed, and an overview of peptide sequences, which were qualified for clinical trials, is given.

Established and Emerging Concepts to Treat Imbalances of Iron Homeostasis in Inflammatory Diseases

Inflammation, being a hallmark of many chronic diseases, including cancer, inflammatory bowel disease, rheumatoid arthritis, and chronic kidney disease, negatively affects iron homeostasis, leading to iron retention in macrophages of the mononuclear phagocyte system. Functional iron deficiency is the consequence, leading to anemia of inflammation (AI). Iron deficiency, regardless of anemia, has a detrimental impact on quality of life so that treatment is warranted. Therapeutic strategies include (1) resolution of the underlying disease, (2) iron supplementation, and (3) iron redistribution strategies. Deeper insights into the pathophysiology of AI has led to the development of new therapeutics targeting inflammatory cytokines and the introduction of new iron formulations. Moreover, the discovery that the hormone, hepcidin, plays a key regulatory role in AI has stimulated the development of several therapeutic approaches targeting the function of this peptide. Hence, inflammation-driven hepcidin elevation causes iron retention in cells and tissues. Besides pathophysiological concepts and diagnostic approaches for AI, this review discusses current guidelines for iron replacement therapies with special emphasis on benefits, limitations, and unresolved questions concerning oral versus parenteral iron supplementation in chronic inflammatory diseases. Furthermore, the review explores how therapies aiming at curing the disease underlying AI can also affect anemia and discusses emerging hepcidin antagonizing drugs, which are currently under preclinical or clinical investigation.

High-throughput screening for small molecule inhibitors of the type-I interferon signaling pathway

Interferons (IFNs) are cytokines with fundamental roles in resistance to infections, cancer and other diseases. Type-I IFNs, interferon α (IFN-α) and interferon β (IFN-β), act through a shared receptor complex (IFNAR) comprised of IFNAR1 and IFNAR2 subunits. Binding of type-I IFN to IFNAR1 will robustly activate Janus activated kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway. Aberrant activation of the type-I IFN response results in a spectrum of disorders called interferonopathies. The purpose of this research is to develop an assay for high-throughput screening (HTS) of small molecule inhibitors of the type-I IFN signaling pathway. Inhibition of type-I IFN signaling can be beneficial in terms of therapeutic use and understanding the underlying mechanism of action. We report here a HTS campaign with the secreted embryonic alkaline phosphatase (SEAP) reporter gene assay against 32,000 compounds which yielded 25 confirmed hits. These compounds were subsequently characterized for their cytotoxicity, effects on STAT phosphorylation and activities in IFN regulatory factor (IRF) transcription.

Ruxolitinib inhibits cyclosporine-induced proliferation of cutaneous squamous cell carcinoma

Organ transplant recipients (OTRs) on cyclosporine A (CSA) are prone to catastrophic cutaneous squamous cell carcinoma (SCC). Allograft-sparing, cancer-targeting systemic treatments are unavailable. We have shown increased risk for catastrophic SCC in OTRs via CSA-mediated induction of IL-22. Herein, we found that CSA drives SCC proliferation and tumor growth through IL-22 and JAK/STAT pathway induction. We in turn inhibited SCC growth with an FDA-approved JAK1/2 inhibitor, ruxolitinib. In human SCC cells, the greatest proliferative response to IL-22 and CSA treatment occurred in nonmetastasizing lines. IL-22 treatment upregulated JAK1 and STAT1/3 in A431 SCC cells. JAK/STAT pathway genes were highly expressed in tumors from a cohort of CSA-exposed OTRs and in SCC with high risk for metastasis. Compared with immunocompetent SCC, genes associated with innate immunity, response to DNA damage, and p53 regulation were differentially expressed in SCC from OTRs. In nude mice engrafted with human A431 cells, IL-22 and CSA treatment increased tumor growth and upregulated IL-22 receptor, JAK1, and STAT1/3 expression. Ruxolitinib treatment significantly reduced tumor volume and reversed the accelerated tumor growth. CSA and IL-22 exacerbate aggressive behavior in SCC. Targeting the IL-22 axis via selective JAK/STAT inhibition may reduce the progression of aggressive SCC in OTRs, without compromising immunosuppression.

The effect of Ganoderma lucidum extract on immunological function and identify its anti-tumor immunostimulatory activity based on the biological network

Ganoderma lucidum extract (GLE) has shown positive effects for tumor treatment. However, the molecular mechanism of GLE treatment is unknown. In this study, a Hepa1-6-bearing C57 BL/6 mouse model was established to explore the anti-tumor and immunostimulatory activity of GLE treatment. The results showed that GLE effectively inhibited tumor growth without hepatic/renal toxicity and bone marrow suppression, and might enhancing immunological function. Based on the mRNA profiles of GLE treated and untreated mice, 302 differentially expressed (DE) mRNAs were identified and 6 kernel mRNAs were identified from the established protein-protein interaction (PPI) network. Quantitative RT-PCR and western-blot analysis indicated that 6 mRNAs have had statistically significant differences between the GLE treated and untreated mice. Furthermore, four kernel pathways were isolated from the KEGG-Target network, including the Jak-STAT signaling pathway, T cell receptor signaling pathway, PI3K-Akt signaling pathway, and cytokine-cytokine receptor interaction. Western-blot and cytokine detection results demonstrated that GLE suppressed growth and proliferation of tumors by the Jak-STAT signaling pathway, T cell receptor signaling pathway and PI3K-Akt signaling pathway, but also regulated the expression levels of serum immune cytokines and improved the anti-tumor immunostimulatory activity.

Differentially expressed JAK-STAT signaling pathway genes and target microRNAs in the spleen of necrotic enteritis-afflicted chicken lines

The JAK signal transducer and STAT signaling pathway is an important regulator of cell proliferation, differentiation, survival, motility, apoptosis, immune response, and development. In this study, we used RNA-Sequencing, qRT-PCR, and bioinformatics tools to investigate the differential expression of JAK-STAT pathway genes, their interactions, and regulators in the spleen of two genetically disparate chicken lines (Marek's disease-resistant line 6.3 and MD-susceptible line 7.2) induced necrotic enteritis (NE) disease by co-infection with Eimeria maxima and Clostridium perfringens. Using RNA-Seq analysis, we identified a total of 116 JAK-STAT pathway genes that were differentially expressed in the spleen of these chickens. All of the identified genes were analyzed through clustering, mapping to the KEGG chicken JAK-STAT pathway, and the Pathway Studio program. Of the 116 JAK-STAT pathway genes, 20 were further verified by qRT-PCR. According to the RNA-Seq results, several key genes, including STAT1-6, JAK1-3, TYK2, AKT1, AKT3, SOCS1-5, PIAS1, PIAS2, PIAS4, SHP1, SHP2, and PIK3, showed marked differential expression in the two lines, relative to their respective controls. Moreover, the RNA-Seq results of many key genes were highly correlated with the qRT-PCR results. Finally, we predicted 63 mature miRNAs that variably target JAK-STAT pathway genes and are differentially expressed in the spleen of chickens of both lines. To the best of our knowledge, this study is the first to analyze most of the genes, interactions, and regulators of the JAK-STAT pathway in the innate immune response to NE disease in chickens.