Mechanisms and consequences of Jak-STAT signaling in the immune system. Nat Immunol. 2017;18:374-384. [PMID: 28323260 DOI: 10.1038/ni.3691]

Temporally integrated transcriptome analysis reveals ASFV pathology and host response dynamics

African swine fever virus (ASFV) causes a lethal swine hemorrhagic disease and is currently responsible for widespread damage to the pig industry. The pathogenesis of ASFV infection and its interaction with host responses remain poorly understood. In this study, we profiled the temporal viral and host transcriptomes in porcine alveolar macrophages (PAMs) with virulent and attenuated ASFV strains. We identified profound differences in the virus expression programs between SY18 and HuB20, which shed light on the pathogenic functions of several ASFV genes. Through integrated computational analysis and experimental validation, we demonstrated that compared to the virulent SY18 strain, the attenuated HuB20 quickly activates expression of receptors, sensors, regulators, as well as downstream effectors, including cGAS, STAT1/2, IRF9, MX1/2, suggesting rapid induction of a strong antiviral immune response in HuB20. Surprisingly, in addition to the pivotal DNA sensing mechanism mediated by cGAS-STING pathway, infection of the DNA virus ASFV activates genes associated with RNA virus response, with stronger induction by HuB20 infection. Taken together, this study reveals novel insights into the host-virus interaction dynamics, and provides reference for future mechanistic studies of ASFV pathogenicity.

Noncanonical JAK1/STAT3 interactions with TGF-β modulate myofibroblast transdifferentiation and fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with limited survival. Janus kinases (JAKs), tyrosine kinases that transduce cytokine-mediated signals, are known to be involved, but their specific roles in lung fibrosis are not well defined. In this study, the interactions between JAK1/signal transducers and activators of transcription (STAT)3 signaling and transforming growth factor-beta (TGF-β)-induced fibroblast responses were investigated using both pharmacological and siRNA approaches in human normal and IPF-derived lung fibroblasts. We found that JAK1 directly interacts with the TGF-β receptor I subunit (TβRI), and silencing JAK1 promotes myofibroblast transdifferentiation. However, the suppression of JAK1 signaling in vitro and in vivo using an inhibitor (upadacitinib) did not alter lung fibroblast activation or fibrosis development. STAT3 was constitutively active in cultured primary lung fibroblasts; this STAT3 activation required JAK1 and repressed myofibroblast transdifferentiation. Loss of phosphorylated STAT3 following transcriptional JAK1 silencing promoted myofibroblast transdifferentiation. In contrast, transcriptional silencing of unphosphorylated STAT3 suppressed TGF-β signaling, decreased SMAD3 activation, and reduced myofibroblast transdifferentiation and ECM production. Taken together, these observations support a role for JAK1/STAT3 as a direct regulator of TGF-β signaling in lung fibroblasts. Modulation of JAK1/STAT3 signaling in lung fibroblasts represents a noncanonical approach to regulating TGF-β-induced fibrosis and suggests the potential for a novel approach to treat pulmonary fibrosis.

Targeting epigenetic regulators for inflammation: Mechanisms and intervention therapy

Emerging evidence indicates that resolution of inflammation is a critical and dynamic endogenous process for host tissues defending against external invasive pathogens or internal tissue injury. It has long been known that autoimmune diseases and chronic inflammatory disorders are characterized by dysregulated immune responses, leading to excessive and uncontrol tissue inflammation. The dysregulation of epigenetic alterations including DNA methylation, posttranslational modifications to histone proteins, and noncoding RNA expression has been implicated in a host of inflammatory disorders and the immune system. The inflammatory response is considered as a critical trigger of epigenetic alterations that in turn intercede inflammatory actions. Thus, understanding the molecular mechanism that dictates the outcome of targeting epigenetic regulators for inflammatory disease is required for inflammation resolution. In this article, we elucidate the critical role of the nuclear factor‐κB signaling pathway, JAK/STAT signaling pathway, and the NLRP3 inflammasome in chronic inflammatory diseases. And we formulate the relationship between inflammation, coronavirus disease 2019, and human cancers. Additionally, we review the mechanism of epigenetic modifications involved in inflammation and innate immune cells. All that matters is that we propose and discuss the rejuvenation potential of interventions that target epigenetic regulators and regulatory mechanisms for chronic inflammation‐associated diseases to improve therapeutic outcomes.

Molecular cloning, expression and functional analysis of STAT2 in orange-spotted grouper, Epinephelus coioides

Signal transducer and activator of transcription 2 (STAT2) is an important molecule involved in the type I interferon signaling pathway. To better understand the functions of STAT2 in fish immune response, a STAT2 gene from orange-spotted grouper (Epinephelus coioides) (EcSTAT2) was cloned and characterized in this study. EcSTAT2 encoded a 802-amino acid peptide which shared 99.5% and 91.5% identity with giant grouper (Epinephelus lanceolatus) and leopard coral grouper (Plectropomus leopardus), respectively. Amino acid alignment analysis showed that EcSTAT2 contained five conserved domains, including N-terminal protein interaction domain, coiled coil domain (CCD), DNA binding domain (DBD), Src-homology 2 (SH2) domain, and C-terminal transactivation domain (TAD). Phylogenetic analysis indicated that EcSTAT2 clustered into fish STAT2 group and showed the nearest relationship to giant grouper STAT2. In healthy grouper, EcSTAT2 was distributed in all tissues tested, and the expression of EcSTAT2 was predominantly detected in spleen, kidney and gill. In vitro, EcSTAT2 expression was significantly increased in response to polyinosinic:polycytidylic acid [poly (I:C)] stimulation and red-spotted grouper nervous necrosis virus (RGNNV) infection. Subcellular localization showed that EcSTAT2 was located in the cytoplasm in a punctate manner. EcSTAT2 overexpression significantly inhibited RGNNV replication, as evidenced by the decreased severity of cytopathic effect (CPE) and the reduced expression levels of viral genes and protein. Consistently, knockdown of EcSTAT2 using small interfering RNA (siRNA) promoted RGNNV replication. Furthermore, EcSTAT2 overexpression increased both interferon (IFN) and interferon stimulated genes (ISGs) expression. In addition, EcSTAT2 knockdown decreased the transcription levels of IFN and ISGs. Together, our data demonstrated that EcSTAT2 exerted antiviral activity against RGNNV through up-regulation of host interferon response.

Human monocytes differentiate into tumor-associated macrophages upon SKOV3 cells coculture and/or lysophosphatidic acid stimulation

Background

Serous ovarian carcinoma is the most common type of ovarian carcinoma. Tumor-associated macrophages (TAMs) promote ovarian cancer progression. Most macrophages are generated by monocyte differentiation. Lysophosphatidic acid (LPA) levels are high in blood, tissues and ascites of patients with ovarian cancer. This study investigated whether human monocytes can directly differentiate into TAMs in the serous ovarian carcinoma microenvironment.

Methods

Human monocytes were isolated and purified from umbilical cord blood. A serous ovarian carcinoma-like microenvironment was generated by coculturing monocytes and SKOV3 cells in 0.4-μm-pore-size Transwell chambers. Additionally, the effect of LPA was assessed. The two cultured cell types and supernatants were evaluated.

Results

The morphology and function of monocytes cocultured with SKOV3 cells and/or stimulated with LPA were significantly changed compared with those of non-stimulated monocytes. The CD14 + CD163 + and CD206 + phenotype indicated that stimulated cells were TAMs. The induced cells promoted SKOV3 cell proliferation and invasion, further proving that they were TAMs. The level of the cytokine interleukin-6R in the supernatant was significantly elevated in the treatment groups compared to the control monocyte group. Pathway enrichment analysis of ELISA results showed a strong influence of interleukin-6 family signaling, especially the JAK-STAT signaling pathway, further confirming the importance of IL-6R.

Conclusion

Monocytes can differentiate into TAMs under coculture with SKOV3 cells and/or LPA stimulation. The induced TAMs promote SKOV3 cell proliferation and invasion. The cytokine receptor IL-6sR and the JAK-STAT signaling pathway play an important role in the differentiation of monocytes into TAMs.

IL-6/STAT3 Signaling Axis Enhances and Prolongs Pdcd1 Expression in Murine CD8 T Cells

CD8 cytotoxic T cells are a potent line of defense against invading pathogens. To aid in curtailing aberrant immune responses, the activation status of CD8 T cells is highly regulated. One mechanism in which CD8 T cell responses are dampened is via signaling through the immune-inhibitory receptor Programmed Cell Death Protein-1, encoded by Pdcd1. Pdcd1 expression is regulated through engagement of the TCR, as well as by signaling from extracellular cytokines. Understanding such pathways has influenced the development of numerous clinical treatments. In this study, we showed that signals from the cytokine IL-6 enhanced Pdcd1 expression when paired with TCR stimulation in murine CD8 T cells. Mechanistically, signals from IL-6 were propagated through activation of the transcription factor STAT3, resulting in IL-6-dependent binding of STAT3 to Pdcd1 cis-regulatory elements. Intriguingly, IL-6 stimulation overcame B Lymphocyte Maturation Protein 1-mediated epigenetic repression of Pdcd1, which resulted in a transcriptionally permissive landscape marked by heightened histone acetylation. Furthermore, in vivo-activated CD8 T cells derived from lymphocytic choriomeningitis virus infection required STAT3 for optimal Programmed Cell Death Protein-1 surface expression. Importantly, STAT3 was the only member of the STAT family present at Pdcd1 regulatory elements in lymphocytic choriomeningitis virus Ag-specific CD8 T cells. Collectively, these data define mechanisms by which the IL-6/STAT3 signaling axis can enhance and prolong Pdcd1 expression in murine CD8 T cells.

In-depth systems biological evaluation of bovine alveolar macrophages suggests novel insights into molecular mechanisms underlying Mycobacterium bovis infection

OBJECTIVE

Bovine tuberculosis (bTB) is a chronic respiratory infectious disease of domestic livestock caused by intracellular Mycobacterium bovis infection, which causes ~$3 billion in annual losses to global agriculture. Providing novel tools for bTB managements requires a comprehensive understanding of the molecular regulatory mechanisms underlying the M. bovis infection. Nevertheless, a combination of different bioinformatics and systems biology methods was used in this study in order to clearly understand the molecular regulatory mechanisms of bTB, especially the immunomodulatory mechanisms of M. bovis infection.

METHODS

RNA-seq data were retrieved and processed from 78 (39 non-infected control vs. 39 M. bovis-infected samples) bovine alveolar macrophages (bAMs). Next, weighted gene co-expression network analysis (WGCNA) was performed to identify the co-expression modules in non-infected control bAMs as reference set. The WGCNA module preservation approach was then used to identify non-preserved modules between non-infected controls and M. bovis-infected samples (test set). Additionally, functional enrichment analysis was used to investigate the biological behavior of the non-preserved modules and to identify bTB-specific non-preserved modules. Co-expressed hub genes were identified based on module membership (MM) criteria of WGCNA in the non-preserved modules and then integrated with protein-protein interaction (PPI) networks to identify co-expressed hub genes/transcription factors (TFs) with the highest maximal clique centrality (MCC) score (hub-central genes).

RESULTS

As result, WGCNA analysis led to the identification of 21 modules in the non-infected control bAMs (reference set), among which the topological properties of 14 modules were altered in the M. bovis-infected bAMs (test set). Interestingly, 7 of the 14 non-preserved modules were directly related to the molecular mechanisms underlying the host immune response, immunosuppressive mechanisms of M. bovis, and bTB development. Moreover, among the co-expressed hub genes and TFs of the bTB-specific non-preserved modules, 260 genes/TFs had double centrality in both co-expression and PPI networks and played a crucial role in bAMs-M. bovis interactions. Some of these hub-central genes/TFs, including PSMC4, SRC, BCL2L1, VPS11, MDM2, IRF1, CDKN1A, NLRP3, TLR2, MMP9, ZAP70, LCK, TNF, CCL4, MMP1, CTLA4, ITK, IL6, IL1A, IL1B, CCL20, CD3E, NFKB1, EDN1, STAT1, TIMP1, PTGS2, TNFAIP3, BIRC3, MAPK8, VEGFA, VPS18, ICAM1, TBK1, CTSS, IL10, ACAA1, VPS33B, and HIF1A, had potential targets for inducing immunomodulatory mechanisms by M. bovis to evade the host defense response.

CONCLUSION

The present study provides an in-depth insight into the molecular regulatory mechanisms behind M. bovis infection through biological investigation of the candidate non-preserved modules directly related to bTB development. Furthermore, several hub-central genes/TFs were identified that were significant in determining the fate of M. bovis infection and could be promising targets for developing novel anti-bTB therapies and diagnosis strategies.

Gene expression analysis in endometriosis: Immunopathology insights, transcription factors and therapeutic targets

Background

Endometriosis is recognized as an estrogen-dependent inflammation disorder, estimated to affect 8%-15% of women of childbearing age. Currently, the etiology and pathogenesis of endometriosis are not completely clear. Underlying mechanism for endometriosis is still under debate and needs further exploration. The involvement of transcription factors and immune mediations may be involved in the pathophysiological process of endometriosis, but the specific mechanism remains to be explored. This study aims to investigate the underlying molecular mechanisms in endometriosis.

Methods

The gene expression profile of endometriosis was obtained from the gene expression omnibus (GEO) database. Gene set variation analysis (GSVA) and gene set enrichment analysis (GSEA) were applied to the endometriosis GSE7305 datasets. Cibersort and MCP-counter were used to explore the immune response gene sets, immune response pathway, and immune environment. Differentially expressed genes (DEGs) were identified and screened. Common biological pathways were being investigated using the kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis. Transcription factors were from The Human Transcription Factors. The least absolute shrinkage and selection operator (Lasso) model identified four differential expressions of transcription factors (AEBP1, HOXB6, KLF2, and RORB). Their diagnostic value was calculated by receiver operating characteristic (ROC) curve analysis and validated in the validation cohort (GSE11691, GSE23339). By constructing the interaction network of crucial transcription factors, weighted gene coexpression network analysis (WGCNA) was used to search for key module genes. Metascape was used for enrichment analysis of essential module genes and obtained HOXB6, KLF2. The HOXB6 and KLF2 were further verified as the only two intersection genes according to Support Vector Machine Recursive Feature Elimination (SVM-RFE) and random forest models. We constructed ceRNA (lncRNA-miRNA-mRNA) networks with four potential transcription factors. Finally, we performed molecular docking for goserelin and dienogest with four transcription factors (AEBP1, HOXB6, KLF2, and RORB) to screen potential drug targets.

Results

Immune and metabolic pathways were enriched in GSVA and GSEA. In single sample gene set enrichment analysis (ssGSEA), most immune infiltrating cells, immune response gene sets, and immune response pathways are differentially expressed between endometriosis and non-endometriosis. Twenty-seven transcription factors were screened from differentially expressed genes. Most of the twenty-seven transcription factors were correlated with immune infiltrating cells, immune response gene sets and immune response pathways. Furthermore, Adipocyte enhancer binding protein 1 (AEBP1), Homeobox B6 (HOXB6), Kruppel Like Factor 2 (KLF2) and RAR Related Orphan Receptor B (RORB) were selected out from twenty-seven transcription factors. ROC analysis showed that the four genes had a high diagnostic value for endometriosis. In addition, KLF2 and HOXB6 were found to play particularly important roles in multiple modules (String, WGCNA, SVM-RFE, random forest) on the gene interaction network. Using the ceRNA network, we found that NEAT1 may regulate the expressions of AEBP1, HOXB6 and RORB, while X Inactive Specific Transcript (XIST) may control the expressions of HOXB6, RORB and KLF2. Finally, we found that goserelin and dienogest may be potential drugs to regulate AEBP1, HOXB6, KLF2 and RORB through molecular docking.

Conclusions

AEBP1, HOXB6, KLF2, and RORB may be potential biomarkers for endometriosis. Two of them, KLF2 and HOXB6, are critical molecules in the gene interaction network of endometriosis. Discovered by molecular docking, AEBP1, HOXB6, KLF2, and RORB are targets for goserelin and dienogest.

From immune equilibrium to immunodynamics

Objective

The immunology field has long been short of a universally applicable theoretical model that can quantitatively describe the immune response, and the theory of immune equilibrium (balance) is usually limited to the interpretation of the philosophical significance of immune phenomena. Therefore, it is necessary to establish a new immunological theory, namely, immunodynamic theory, to reanalyze the immune response.

Methods

By quantifying the immune dynamic equilibrium as the ratio of positive and negative immune power, the immune dynamic equilibrium equation was established. Then, the area under the curve of the positive and negative immune power was assumed to be equal in the whole process of immune response (regardless of correct or not), and through thought experiments based on this key hypothesis, a series of new concepts and expressions were derived, to establish a series of immunodynamic equations.

Results

New concepts of immune force and immune braking force and their expression equations, namely, the theoretical equations of immunodynamics, were derived through thought experiments, and the theoretical curves of immunodynamics were obtained according to these equations. Via the equivalent transformation of the theoretical equations and practical calculation of functional data, and by the methods of curve comparison and fitting, some practical equations of immunodynamics were established, and these practical equations were used to solve theoretical and practical problems that are related to the immunotherapy of infectious diseases and cancers.

Conclusion

The traditional theory of immune equilibrium has been mathematized and transformed from a philosophical category into a new concrete scientific theory, namely the theory of immunodynamics, which solves the dilemma that the traditional theory cannot guide individualized medical practice for a long time. This new theory may develop into one of the core theories of immunology in the future.

A central role for STAT5 in the transcriptional programing of T helper cell metabolism

Activated lymphocytes adapt their metabolism to meet the energetic and biosynthetic demands imposed by rapid growth and proliferation. Common gamma chain (cγ) family cytokines are central to these processes, but the role of downstream signal transducer and activator of transcription 5 (STAT5) signaling, which is engaged by all cγ members, is poorly understood. Using genome-, transcriptome-, and metabolome-wide analyses, we demonstrate that STAT5 is a master regulator of energy and amino acid metabolism in CD4+ T helper cells. Mechanistically, STAT5 localizes to an array of enhancers and promoters for genes encoding essential enzymes and transporters, where it facilitates p300 recruitment and epigenetic remodeling. We also find that STAT5 licenses the activity of two other key metabolic regulators, the mTOR signaling pathway and the MYC transcription factor. Building on the latter, we present evidence for transcriptome-wide cooperation between STAT5 and MYC in both normal and transformed T cells. Together, our data provide a molecular framework for transcriptional programing of T cell metabolism downstream of cγ cytokines and highlight the JAK-STAT pathway in mediating cellular growth and proliferation.

Signaling pathways in cancer-associated fibroblasts: recent advances and future perspectives

As a critical component of the tumor microenvironment (TME), cancer-associated fibroblasts (CAFs) play important roles in cancer initiation and progression. Well-known signaling pathways, including the transforming growth factor-β (TGF-β), Hedgehog (Hh), Notch, Wnt, Hippo, nuclear factor kappa-B (NF-κB), Janus kinase (JAK)/signal transducer and activator of transcription (STAT), mitogen-activated protein kinase (MAPK), and phosphoinositide 3-kinase (PI3K)/AKT pathways, as well as transcription factors, including hypoxia-inducible factor (HIF), heat shock transcription factor 1 (HSF1), P53, Snail, and Twist, constitute complex regulatory networks in the TME to modulate the formation, activation, heterogeneity, metabolic characteristics and malignant phenotype of CAFs. Activated CAFs remodel the TME and influence the malignant biological processes of cancer cells by altering the transcriptional and secretory characteristics, and this modulation partially depends on the regulation of signaling cascades. The results of preclinical and clinical trials indicated that therapies targeting signaling pathways in CAFs demonstrated promising efficacy but were also accompanied by some failures (e.g., NCT01130142 and NCT01064622). Hence, a comprehensive understanding of the signaling cascades in CAFs might help us better understand the roles of CAFs and the TME in cancer progression and may facilitate the development of more efficient and safer stroma-targeted cancer therapies. Here, we review recent advances in studies of signaling pathways in CAFs and briefly discuss some future perspectives on CAF research.

JAK1 inactivation promotes proliferation and migration of endometrial cancer cells via upregulating the hypoxia-inducible factor signaling pathway

BACKGROUND

Loss-of-function (LOF) mutations of JAK1, a member of the JAK kinase family, were frequently observed in EC, indicating that JAK1 may act as a tumor suppressor, at least in EC. However, the mechanism of JAK1 mediated regulation of tumorigenesis remains poorly understood.

METHODS

The genetic alterations of JAK1 in EC using latest sequencing dataset of EC deposited in TCGA database. The RNA-Seq dataset of EC and normal endometrial tissues from TCGA cohort was analyzed. The expression of JAK1 in EC and normal endometrial tissues were investigated using immunohistochemistry. The expression levels of genes in endometrial cancer cells were detected by quantitative reverse transcription-PCR (RT-qPCR) and western blotting. JAK1 protein was efficiently depleted by the two shRNAs. HIF1/2-α protein was efficiently depleted by siRNAs. JAK1 overexpressed EC cells were generated by an expressing plasmid. The proliferation and migration ability of cancer cells were evaluated by CCK8, colony formation assays and transwell assays. The global transcriptomic changes in JAK1-depleted KLE cells were investigated using RNA-Seq. Gene Ontology (GO) Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were used to identify the most significant pathways that were altered in JAK1-depleted KLE cells. The physical association between HIF-1/2α and JAK1 using co-immunoprecipitation (co-IP) assays.

RESULTS

In the present study, we found that JAK1 was frequently mutated and downregulated in EC. JAK1 knockdown promotes EC cell proliferation and migration. JAK1 overexpression reduces EC cell proliferation and migration. We examined the transcriptional profiling changes in JAK1-depleted EC cells and unexpectedly found that the hypoxia inducible factor (HIF) pathway was activated. Mechanistically, JAK1 interacts with HIF-1/2α, and reduces HIF1/2-α protein expression under hypoxia. HIF-1/2α knockdown reverses the JAK1 knockdown-induced growth and migration of EC cells under hypoxia. JAK1 knockdown or pharmacological inhibition of JAK1 kinase activity by Ruxolitinib upregulates transcription of HIF target genes under hypoxia. JAK1 overexpression downregulates transcription of HIF target genes under hypoxia.

CONCLUSIONS

These findings provide novel insights into the functional link between JAK1 LOF mutations and abnormal HIF pathway activation in EC and suggest that pharmacological inhibition of HIF1/2 represents a promising therapeutic strategy targeting JAK1-mutated ECs. Video Abstract.

Efficacy and Safety of Upadacitinib for Management of Moderate-to-Severe Atopic Dermatitis: An Evidence-Based Review

Atopic dermatitis (AD) is a common skin condition characterized by inflammation that presents with erythematous and pruritic skin. Its chronic relapse-remitting nature has a significant impact on the quality of life, and often requires ongoing management. Given the limited treatments available for AD, there remains a large need for effective and safe alternative therapies for long-term use. Janus kinase (JAK) inhibitors are a new class of agents that target the JAK-STAT pathway, which plays an important role in the production of proinflammatory cytokines involved in AD pathogenesis. Phase II and III clinical trials revealed that JAK inhibitors, such as upadacitinib, are effective and well-tolerated agents for the treatment of moderate-to-severe AD. As a result, upadacitinib was approved for use in patients with moderate-to-severe AD by the European Medicines Agency (2021), Health Canada (2021) and the FDA (2022) in the last year. It is important for dermatologists to be aware of the clinical evidence to continue incorporating the use of upadacitinib into the treatment algorithm for AD, which will ultimately lead to improved patient outcomes. Therefore, this review is an up-to-date summary of the clinical data available on the efficacy and safety of upadacitinib treatment for AD.

Leukemia inhibitory factor protects against graft-versus-host disease while preserving graft-versus-leukemia activity

Graft-versus-host disease (GVHD) remains a major complication after allogeneic hematopoietic stem cell transplantation, a widely used therapy for hematologic malignancies and blood disorders. Here, we report an unexpected role of cytokine leukemia inhibitory factor (LIF) in protecting against GVHD development. Administrating recombinant LIF protein (rLIF) protects mice from GVHD-induced tissue damage and lethality without compromising the graft-versus-leukemia activity, which is crucial to prevent tumor relapse. We found that rLIF decreases the infiltration and activation of donor immune cells and protects intestinal stem cells to ameliorate GVHD. Mechanistically, rLIF downregulates IL-12-p40 expression in recipient dendritic cells after irradiation through activating STAT1 signaling, which results in decreased major histocompatibility complex II levels on intestinal epithelial cells and decreased donor T-cell activation and infiltration. This study reveals a previously unidentified protective role of LIF for GVHD-induced tissue pathology and provides a potential effective therapeutic strategy to limit tissue pathology without compromising antileukemic efficacy.

Novel TYK2 Inhibitors with an N-(Methyl-d 3)pyridazine-3-carboxamide Skeleton for the Treatment of Autoimmune Diseases

Tyrosine kinase 2 (TYK2) mediates the interleukin-23 (IL-23), IL-12, and type I interferon (IFN)-driven signal responses that are critical in autoimmune diseases. Here, a series of novel derivatives with an N-(methyl-d 3)pyridazine-3-carboxamide skeleton that bind to the TYK2 pseudokinase domain were designed, synthesized, and evaluated. Among them, compound 30 demonstrated more excellent inhibitory potency against STAT3 phosphorylation than the positive control deucravacitinib. In addition to JAK isoform selectivity, compound 30 exhibited good in vivo and in vitro pharmacokinetic properties. Furthermore, compound 30 was orally highly effective in both IL-23-driven acanthosis and anti-CD40-induced colitis models. Together, these findings support compound 30 as a promising candidate for therapeutic applications in autoimmune diseases.

A human STAT3 gain-of-function variant confers T cell dysregulation without predominant Treg dysfunction in mice

Primary immune regulatory disorders (PIRD) represent a group of disorders characterized by immune dysregulation, presenting with a wide range of clinical disease, including autoimmunity, autoinflammation, or lymphoproliferation. Autosomal dominant germline gain-of-function (GOF) variants in STAT3 result in a PIRD with a broad clinical spectrum. Studies in patients have documented a decreased frequency of FOXP3+ Tregs and an increased frequency of Th17 cells in some patients with active disease. However, the mechanisms of disease pathogenesis in STAT3 GOF syndrome remain largely unknown, and treatment is challenging. We developed a knock-in mouse model harboring a de novo pathogenic human STAT3 variant (p.G421R) and found these mice developed T cell dysregulation, lymphoproliferation, and CD4+ Th1 cell skewing. Surprisingly, Treg numbers, phenotype, and function remained largely intact; however, mice had a selective deficiency in the generation of iTregs. In parallel, we performed single-cell RNA-Seq on T cells from STAT3 GOF patients. We demonstrate only minor changes in the Treg transcriptional signature and an expanded, effector CD8+ T cell population. Together, these findings suggest that Tregs are not the primary driver of disease and highlight the importance of preclinical models in the study of disease mechanisms in rare PIRD.

Unleashing Intrinsic Growth Pathways in Regenerating Peripheral Neurons

Common mechanisms of peripheral axon regeneration are recruited following diverse forms of damage to peripheral nerve axons. Whether the injury is traumatic or disease related neuropathy, reconnection of axons to their targets is required to restore function. Supporting peripheral axon regrowth, while not yet available in clinics, might be accomplished from several directions focusing on one or more of the complex stages of regrowth. Direct axon support, with follow on participation of supporting Schwann cells is one approach, emphasized in this review. However alternative approaches might include direct support of Schwann cells that instruct axons to regrow, manipulation of the inflammatory milieu to prevent ongoing bystander axon damage, or use of inflammatory cytokines as growth factors. Axons may be supported by a growing list of growth factors, extending well beyond the classical neurotrophin family. The understanding of growth factor roles continues to expand but their impact experimentally and in humans has faced serious limitations. The downstream signaling pathways that impact neuron growth have been exploited less frequently in regeneration models and rarely in human work, despite their promise and potency. Here we review the major regenerative signaling cascades that are known to influence adult peripheral axon regeneration. Within these pathways there are major checkpoints or roadblocks that normally check unwanted growth, but are an impediment to robust growth after injury. Several molecular roadblocks, overlapping with tumour suppressor systems in oncology, operate at the level of the perikarya. They have impacts on overall neuron plasticity and growth. A second approach targets proteins that largely operate at growth cones. Addressing both sites might offer synergistic benefits to regrowing neurons. This review emphasizes intrinsic aspects of adult peripheral axon regeneration, emphasizing several molecular barriers to regrowth that have been studied in our laboratory.

Transcriptome profiling based on protein-protein networks provides a core set of genes for understanding blood immune response mechanisms against LPS stress in Amphioctopus fangsiao

Gram-negative bacteria are significant pathogens in the ocean, posing serious threats to marine organisms. Lipopolysaccharide (LPS) is a characteristic chemical constituent in Gram-negative bacteria that can be recognized by the pattern recognition receptor (PRR) of immune cells. This system is often used to simulate the invasion of bacteria. Blood is a transport channel for immune cells, and its transcriptome information obtained from Amphioctopus fangsiao stimulated by LPS is essential for understanding the antibacterial biological mechanisms of this species. In this study, we analyzed the gene expression profiles of A. fangsiao blood within 24h under LPS stress and found 778 and 561 differentially expressed genes (DEGs) at 6 and 24h, respectively. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analyses were performed to search for immune-related DEGs. The relationships among immune genes were examined by constructing a protein-protein interaction (PPI) network. Finally, 16 hub genes were identified based on the PPI network and KEGG enrichment analysis. The expression profiles of these genes were verified using quantitative RT-PCR (qRT-PCR). This research provides valuable resources for the healthy culture of A. fangsiao and helps us understand the molecular mechanisms of innate immunity.

Toxicity of tributyltin chloride on haarder (Liza haematocheila) after its acute exposure: Bioaccumulation, antioxidant defense, histological, and transcriptional analyses

Liza haematocheila is exposed to various chemical contaminants from anthropogenic sources, including tributyltin chloride (TBTC). Yet the toxicity mechanism of TBTC on haarder remains unclear. The haarder was exposed to different doses (0, 10%, 20%, and 50% of LC₅₀-96 h) of TBTC. In this study, the results revealed its high bioaccumulation in the livers and significant alteration for development. The activities of antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase decreased after 96-h exposure to TBTC, this accompanied by an increased malondialdehyde level. TBTC exposure caused the intense production of reactive oxygen species, a reduction in total blood cell count in serum, and apoptosis-related alterations in livers, indicating that enhanced oxidative stress occurred in the process of TBTC exposure. Histological results revealed angiorrhexis and infiltration of inflammatory cells, vacuolar degeneration of hepatocytes in the livers, and swelling, fusion, and disintegration of gill organs. Interestingly, the obtained transcriptional profiles indicated that high doses of TBTC caused energy disorder, apoptosis, and adipogenesis restriction mediated by cytokines and adipokines in Jak-STAT and adipocytokine signaling pathways. In summary, acute exposure to high doses of TBTC could impair the antioxidant system and pathways related to energy, apoptosis and adipogenesis, eventually posing a serious challenge to the fitness of haarder individuals and its fish populations as marine resources.

STAT family of transcription factors in breast cancer: Pathogenesis and therapeutic opportunities and challenges

Breast cancer is the most commonly diagnosed cancer and second-leading cause of cancer deaths in women. Breast cancer stem cells (BCSCs) promote metastasis and therapeutic resistance contributing to tumor relapse. Through activating genes important for BCSCs, transcription factors contribute to breast cancer metastasis and therapeutic resistance, including the signal transducer and activator of transcription (STAT) family of transcription factors. The STAT family consists of six major isoforms, STAT1, STAT2, STAT3, STAT4, STAT5, and STAT6. Canonical STAT signaling is activated by the binding of an extracellular ligand to a cell-surface receptor followed by STAT phosphorylation, leading to STAT nuclear translocation and transactivation of target genes. It is important to note that STAT transcription factors exhibit diverse effects in breast cancer; some are either pro- or anti-tumorigenic while others maintain dual, context-dependent roles. Among the STAT transcription factors, STAT3 is the most widely studied STAT protein in breast cancer for its critical roles in promoting BCSCs, breast cancer cell proliferation, invasion, angiogenesis, metastasis, and immune evasion. Consequently, there have been substantial efforts in developing cancer therapeutics to target breast cancer with dysregulated STAT3 signaling. In this comprehensive review, we will summarize the diverse roles that each STAT family member plays in breast cancer pathobiology, as well as, the opportunities and challenges in pharmacologically targeting STAT proteins and their upstream activators in the context of breast cancer treatment.

Antifibrotic TSG-6 Expression Is Synergistically Increased in Both Cells during Coculture of Mesenchymal Stem Cells and Macrophages via the JAK/STAT Signaling Pathway

The pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-1β upregulate TNF-α-stimulated gene 6 (TSG-6); however, current knowledge about the optimal conditions for TSG-6 expression in mesenchymal stem cells (MSCs) is limited. Here, we investigated whether TSG-6 expression varies depending on the polarization state of macrophages co-cultured with adipose tissue-derived stem cells (ASCs) and analyzed the optimal conditions for TSG-6 expression in ASCs. TSG-6 expression increased in ASCs co-cultured with M0, M1, and M2 macrophages indirectly; among them, M1 macrophages resulted in the highest increase in TSG-6 expression in ASCs. TSG-6 expression in ASCs dramatically increased by combination (but not single) treatment of TNF-α, IL-1β, interferon-gamma (IFN-γ), and lipopolysaccharide (LPS). In addition, phosphorylation of signal transducer and activator of transcription (STAT) 1/3 was observed in response to IFN-γ and LPS treatment but not TNF-α and/or IL-1β. STAT1/3 activation synergistically increased TNF-α/IL-1β-dependent TSG-6 expression, and JAK inhibitors suppressed TSG-6 expression both in ASCs and macrophages. In LX-2 hepatic stellate cells, TSG-6 inhibited TGF-β-induced Smad3 phosphorylation, resulting in decreased α-smooth muscle actin (SMA) expression. Moreover, fibrotic activities of LX-2 cells induced by TGF-β were dramatically decreased after indirect co-culture with ASCs and M1 macrophages. These results suggest that a comprehensive inflammatory microenvironment may play an important role in determining the therapeutic properties of ASCs by increasing TSG-6 expression through STAT1/3 activation.

Modulation of STAT-1, STAT-3, and STAT-6 activities in THP-1 derived macrophages infected with two Trypanosoma cruzi strains

Trypanosoma cruzi is the causative protozoan of Chagas’ Disease, a neglected tropical disease that affects 6−7 million people worldwide. Interaction of the parasite with the host immune system is a key factor in disease progression and chronic symptoms. Although the human immune system is capable of controlling the disease, the parasite has numerous evasion mechanisms that aim to maintain intracellular persistence and survival. Due to the pronounced genetic variability of T. cruzi, co-infections or mixed infections with more than one parasite strain have been reported in the literature. The intermodulation in such cases is unclear. This study aimed to evaluate the co-infection of T. cruzi strains G and CL compared to their individual infections in human macrophages derived from THP-1 cells activated by classical or alternative pathways. Flow cytometry analysis demonstrated that trypomastigotes were more infective than extracellular amastigotes (EAs) and that strain G could infect more macrophages than strain CL. Classically activated macrophages showed lower number of infected cells and IL-4-stimulated cells displayed increased CL-infected macrophages. However, co-infection was a rare event. CL EAs decreased the production of reactive oxygen species (ROS), whereas G trypomastigotes displayed increased ROS detection in classically activated cells. Co-infection did not affect ROS production. Monoinfection by strain G or CL mainly induced an anti-inflammatory cytokine profile by decreasing inflammatory cytokines (IFN-γ, TNF-α, IL-1β) and/or increasing IL-4, IL-10, and TGF-β. Co-infection led to a predominant inflammatory milieu, with reduced IL-10 and TGF-β, and/or promotion of IFN-γ and IL-1β release. Infection by strain G reduced activation of intracellular signal transducer and activator of transcription (STAT) factors. In EAs, monoinfections impaired STAT-1 activity and promoted phosphorylation of STAT-3, both changes may prolong cell survival. Coinfected macrophages displayed pronounced activation of all STATs examined. These activations likely promoted parasite persistence and survival of infected cells. The collective results demonstrate that although macrophages respond to both strains, T. cruzi can modulate the intracellular environment, inducing different responses depending on the strain, parasite infective form, and co-infection or monoinfection. The modulation influences parasite persistence and survival of infected cells.

A Systematic Review of Atopic Dermatitis: The Intriguing Journey Starting from Physiopathology to Treatment, from Laboratory Bench to Bedside

Atopic dermatitis (AD) is a common chronic inflammatory and immune-mediated skin disease with a complex pathophysiology and still represents a therapeutic challenge, owing to limited responses to available treatments. However, recent advances in the understanding of AD pathophysiology have led to the discovery of several new potential therapeutic targets, and research in the field of new molecules with therapeutic perspectives is boiling, with more than 70 new promising drugs in development. The aim of this systematic review is to provide the state of the art on the current knowledge concerning the pathophysiology of the disease and on novel agents currently being investigated for AD, and to highlight which type of evolution is going to take place in therapeutic approaches of atopic dermatitis in the coming years.

The influenza virus PB2 protein evades antiviral innate immunity by inhibiting JAK1/STAT signalling

Influenza A virus (IAV) polymerase protein PB2 has been shown to partially inhibit the host immune response by blocking the induction of interferons (IFNs). However, the IAV PB2 protein that regulates the downstream signaling pathway of IFNs is not well characterized. Here, we report that IAV PB2 protein reduces cellular sensitivity to IFNs, suppressing the activation of STAT1/STAT2 and ISGs. Furthermore, IAV PB2 protein targets mammalian JAK1 at lysine 859 and 860 for ubiquitination and degradation. Notably, the H5 subtype of highly pathogenic avian influenza virus with I283M/K526R mutations on PB2 increases the ability to degrade mammalian JAK1 and exhibits higher replicate efficiency in mammalian (but not avian) cells and mouse lung tissues, and causes greater mortality in infected mice. Altogether, these data describe a negative regulatory mechanism involving PB2-JAK1 and provide insights into an evasion strategy from host antiviral immunity employed by IAV.

JAK/STAT Pathway Targeting in Primary Sjögren Syndrome

Primary Sjögren's syndrome (pSS) is an autoimmune systemic disease mainly affecting exocrine glands and resulting in disabling symptoms, as dry eye and dry mouth. Mechanisms underlying pSS pathogenesis are intricate, involving multiplanar and, at the same time, interlinked levels, e.g., genetic predisposition, epigenetic modifications and the dysregulation of both immune system and glandular-resident cellular pathways, mainly salivary gland epithelial cells. Unravelling the biological and molecular complexity of pSS is still a great challenge but much progress has been made in recent years in basic and translational research field, allowing the identification of potential novel targets for therapy development. Despite such promising novelties, however, none therapy has been specifically approved for pSS treatment until now. In recent years, growing evidence has supported the modulation of Janus kinases (JAK) - signal transducers and activators of transcription (STAT) pathways as treatment strategy immune mediated diseases. JAK-STAT pathway plays a crucial role in autoimmunity and systemic inflammation, being involved in signal pathways of many cytokines. This review aims to report the state-of-the-art about the role of JAK-STAT pathway in pSS, with particular focus on available research and clinical data regarding the use of JAK inhibitors in pSS.

Fedratinib: a pharmacotherapeutic option for JAK-inhibitor naïve and exposed patients with myelofibrosis

INTRODUCTION

Ruxolitinib is the most commonly used JAK-inhibitor (JAKi) for the management of symptoms related to splenomegaly and cytokine-mediated inflammation in patients with myelofibrosis (MF), but is limited by variable durability of response with most patients experiencing failure after 2-3 years. Long-term data on other approved JAKi, fedratinib and pacritinib, are not available due to the clinical hold put on pivotal trials for toxicity concerns.

AREAS COVERED

Following the initial hold for concern of Wernicke's encephalopathy, fedratinib was approved by the Food and Drug Administration (FDA) in 2019 for MF. We review the data available from early, and late phase critical trials, outline a role for fedratinib in the current treatment landscape of MF, and highlight the knowledge gaps in optimizing use of fedratinib.

EXPERT OPINION

The JAKARTA and JAKARTA2 trials established efficacy in spleen volume response (SVR) and symptom reduction in JAKi-naïve and ruxolitinib-exposed MF patients, respectively. Further trials, FREEDOM and FREEDOM2, are in progress to understand long-term effects of fedratinib; and include strategies to mitigate gastrointestinal toxicity, monitor thiamine levels and surveil for encephalopathy. We use fedratinib for symptomatic MF following ruxolitinib failure in patients without significant cytopenias; with practical strategies for monitoring and managing potential toxicity.

Upregulation of programmed cell death 1 by interferon gamma and its biological functions in human monocytes

Programmed cell death 1 (PD-1) is a co-inhibitory checkpoint receptor expressed in various immune cells, especially in activated T cells. Engagement of PD-1 with its ligand leads to the exhausted T cells and impaired antitumor immunity. To date, PD-1 expression and its roles have been widely reported in T cells but not well defined in innate immune cells including monocytes. In this study, expression of PD-1 was investigated in human monocytes. Here we observed that among cytokines tested, IFN-γ significantly upregulated the PD-1 expression in both THP-1 cell line and human primary monocytes in a dose- and time-dependent manner. This effect was reduced by PI3K inhibitor, suggesting that the involvement of PI3K/AKT pathway. Furthermore, enrichment of active histone mark H3K4me3 in the Pdcd1 promotor was also observed in IFN-γ-induced THP-1, indicating that epigenetic regulation also plays a role in IFN-γ-induced PD-1 expression. To investigate the biological functions of PD-1, Pdcd1 was deleted in THP-1 cell line by CRISPR/Cas9 system and the phagocytic ability was investigated. The results showed that the PD-1 deficiency in THP-1 cell line resulted in significantly poor phagocytic potency against carboxylated-modified latex beads. Moreover, the PD-1 deficiency or blocking PD-1/PD-L1 interaction by immune checkpoint inhibitor resulted in an impaired induction of IL-4-induced CD163 expression in THP-1 cell line. Taken together, these results highlighted the importance of PD-1 expression in some of key monocyte functions.

•

Interferon gamma treatment induces PD-1 upregulation in human monocytes.

•

PI3K/AKT pathway is crucial for IFN-γ-induced PD-1 expression.

•

Active histone mark H3K4me3 in Pdcd1 promoter accompanies IFN-γ treatment.

•

PD-1 knockout in THP-1 cell line impairs phagocytosis and M2 polarization.

STAT3 Inhibitors: A Novel Insight for Anticancer Therapy of Pancreatic Cancer

The signal transducer and activator of transcription (STAT) is a family of intracellular cytoplasmic transcription factors involved in many biological functions in mammalian signal transduction. Among them, STAT3 is involved in cell proliferation, differentiation, apoptosis, and inflammatory responses. Despite the advances in the treatment of pancreatic cancer in the past decade, the prognosis for patients with pancreatic cancer remains poor. STAT3 has been shown to play a pro-cancer role in a variety of cancers, and inhibitors of STAT3 are used in pre-clinical and clinical studies. We reviewed the relationship between STAT3 and pancreatic cancer and the latest results on the use of STAT3 inhibitors in pancreatic cancer, with the aim of providing insights and ideas around STAT3 inhibitors for a new generation of chemotherapeutic modalities for pancreatic cancer.

Prenatal immune stress blunts microglia reactivity, impairing neurocircuitry

Recent studies suggested that microglia, the primary brain immune cells, can affect circuit connectivity and neuronal function1,2. Microglia infiltrate the neuroepithelium early in embryonic development and are maintained in the brain throughout adulthood3,4. Several maternal environmental factors-such as an aberrant microbiome, immune activation and poor nutrition-can influence prenatal brain development5,6. Nevertheless, it is unknown how changes in the prenatal environment instruct the developmental trajectory of infiltrating microglia, which in turn affect brain development and function. Here we show that, after maternal immune activation (MIA) in mice, microglia from the offspring have a long-lived decrease in immune reactivity (blunting) across the developmental trajectory. The blunted immune response was accompanied by changes in chromatin accessibility and reduced transcription factor occupancy of the open chromatin. Single-cell RNA-sequencing analysis revealed that MIA does not induce a distinct subpopulation but, rather, decreases the contribution to inflammatory microglia states. Prenatal replacement of microglia from MIA offspring with physiological infiltration of naive microglia ameliorated the immune blunting and restored a decrease in presynaptic vesicle release probability onto dopamine receptor type-two medium spiny neurons, indicating that aberrantly formed microglia due to an adverse prenatal environment affect the long-term microglia reactivity and proper striatal circuit 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.

JAK kinase inhibitors and varicella zoster virus infection in patients with rheumatoid arthritis. Systematic review of the literature

OBJECTIVES

JAK kinase inhibitors (JAKi) are a new therapeutic option in the treatment of rheumatoid arthritis, but they are not without risks, especially the incidence of herpes zoster (HZ).

MATERIAL AND METHODS

Systematic literature review that evaluates the incidence of HZ published in the clinical trials of the different JAK is marketed or under study.

RESULTS

The HZ rates ranged between 1.51 and 20.22. The results were expressed mainly as a percentage of events. The most recent studies better categorized the incidence of HZ and its severity.

CONCLUSION

JAK is are associated with an increased risk of HZ. Although the HZ rates of the selective JAK1 JAK is are lower, more studies are needed to confirm these results.

Comparative efficacy and safety of JAK inhibitors as monotherapy and in combination with methotrexate in patients with active rheumatoid arthritis: A systematic review and meta-analysis

Background

We aim to evaluate the efficacy and tolerability of Janus kinase inhibitors (JAKi) as monotherapy and in combination with methotrexate (MTX) in active rheumatoid arthritis (RA).

Methods

Medline, EMBASE, and Cochrane Library were systematically searched to identify relevant randomized controlled trials (RCTs). Pooled analysis was conducted using random-effects model, along with the risk difference (RD) and 95% confidence intervals (CIs).

Results

Three RCTs, including 2,290 patients, were included. JAKi (tofacitinib, baricitinib, and filgotinib) plus MTX displayed a higher proportion of patients meeting the American College of Rheumatology (ACR) criteria than JAKi alone at week 52 (ACR20 RD 0.032; 95% CI −0.027 to 0.091; ACR50 RD 0.050; 95% CI 0.003 to 0.097; ACR70 RD 0.056; 95% CI 0.012 to 0.100). Similar results were observed for ACR20/50/70 at week 24. No significant difference was found between two regimens for the proportion of patients achieving Health Assessment Questionnaire disability index (HAQ-DI) improvement ≥ 0.22 at weeks 24 and 52. Regarding low disease activity and remission achievement, JAKi in combination with MTX, contributed higher response rates than JAKi alone at weeks 24 and 52. Compared with JAKi monotherapy, combination therapy had a higher risks of treatment-emergent adverse events (TEAEs) and adverse events (AEs) leading to study discontinuation.

Conclusion

JAKi combined with MTX demonstrated superiority to JAKi monotherapy in terms of ACR responses, low disease activity and remission achievement. The two regimens presented comparable physical functioning measured by HAQ-DI improvement and similar tolerability, except for high risks of TEAEs and AEs leading to study discontinuation in combination therapy.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42021288907.

AMBRA1 and its role as a target for anticancer therapy

The activating molecule in Beclin1-regulated autophagy protein 1 (AMBRA1) is an intrinsically disordered protein that regulates the survival and death of cancer cells by modulating autophagy. Although the roles of autophagy in cancer are controversial and context-dependent, inhibition of autophagy under some circumstances can be a useful strategy for cancer therapy. As AMBRA1 is a pivotal autophagy-associated protein, targeting AMBRA1 similarly may be an underlying strategy for cancer therapy. Emerging evidence indicates that AMBRA1 can also inhibit cancer formation, maintenance, and progression by regulating c-MYC and cyclins, which are frequently deregulated in human cancer cells. Therefore, AMBRA1 is at the crossroad of autophagy, tumorigenesis, proliferation, and cell cycle. In this review, we focus on discussing the mechanisms of AMBRA1 in autophagy, mitophagy, and apoptosis, and particularly the roles of AMBRA1 in tumorigenesis and targeted therapy.

Impact of high temperature, CO2 and parasitic infection on inflammation, immunodepression and programmed cell death in Colossoma macropomum at the transcriptional level

The production of tambaqui Colossoma macropomum has recently reached a milestone, being considered the main native species produced in South American continental waters. Despite the importance of this fish, its immunity is poorly understood, and global warming could pose severe risks to its health as increasing water temperature leads to an increase in the incidence of parasitic diseases. In an experimental context based on the high-emission scenario of the 5th Intergovernmental Panel on Climate Change (IPCC) report, we evaluated the synergistic effect of exposure to the extreme climate change scenario (RCP8.5) during two exposure periods (7 and 30 days) and two levels of parasitism by monogeneans (low and high). The goal was to understand how the tambaqui immune system will react to this challenge. To achieve this goal, we analyzed the expression of nine immunity-related genes (jak3, stat3, il-10, socs1, casp1, il-1β, tp53, bcl2, and hif-1α) in the spleen. Our main findings showed downregulation in the jak3/stat3 pathway, genes related to the control of inflammation and apoptosis, in addition to upregulation of proinflammatory genes and those related to pyroptosis during the first 7 days of exposure to the extreme climate scenario, also indicating a stage of immunodepression in these animals. After 30 days of exposure, all genes tended to return to similar levels in the current scenario, possibly due to the decrease in parasite load caused by chronic exposure to the extreme scenario. Our data strongly suggest that the increase in parasitism intensity caused by the extreme climate change scenario is responsible for disturbances in the host's immune system. However, more studies are needed to clarify this poorly understood cascade of events.

Breast Tumor Cell-Stimulated Bone Marrow-Derived Mesenchymal Stem Cells Promote the Sprouting Capacity of Endothelial Cells by Promoting VEGF Expression, Mediated in Part through HIF-1α Increase

Simple Summary

ROS and JAK/Stat3 cooperatively upregulate the expression of HIF-1α in bone marrow-derived mesenchymal stem cells under normoxic conditions in response to breast tumor cells. The upregulation of HIF-1α contributes in part to the increase in VEGF expression in the bone marrow-derived mesenchymal stem cells. Bone marrow-derived mesenchymal stem cells improve the angiogenic sprouting capacity of mature endothelial cells in a VEGF-dependent manner.

Abstract

Breast tumor cells recruit bone marrow-derived mesenchymal stem cells (BM-MSCs) and alter their cellular characteristics to establish a tumor microenvironment. BM-MSCs enhance tumor angiogenesis through various mechanisms. We investigated the mechanisms by which BM-MSCs promote angiogenesis in response to breast tumor. Conditioned media from MDA-MB-231 (MDA CM) and MCF7 (MCF7 CM) breast tumor cells were used to mimic breast tumor conditions. An in vitro spheroid sprouting assay using human umbilical vein endothelial cells (HUVECs) was conducted to assess the angiogenesis-stimulating potential of BM-MSCs in response to breast tumors. The ROS inhibitor N-acetylcysteine (NAC) and JAK inhibitor ruxolitinib attenuated increased HIF-1α in BM-MSCs in response to MDA CM and MCF7 CM. HIF-1α knockdown or HIF-1β only partially downregulated VEGF expression and, therefore, the sprouting capacity of HUVECs in response to conditioned media from BM-MSCs treated with MDA CM or MCF7 CM. Inactivation of the VEGF receptor using sorafenib completely inhibited the HUVECs’ sprouting. Our results suggest that increased HIF-1α expression under normoxia in BM-MSCs in response to breast tumor cells is mediated by ROS and JAK/Stat3, and that both HIF-1α-dependent and -independent mechanisms increase VEGF expression in BM-MSCs to promote the angiogenic sprouting capacity of endothelial cells in a VEGF-dependent manner.

Post-transcriptional regulatory feedback encodes JAK-STAT signal memory of interferon stimulation

Immune cells fine tune their responses to infection and inflammatory cues. Here, using live-cell confocal microscopy and mathematical modelling, we investigate interferon-induced JAK-STAT signalling in innate immune macrophages. We demonstrate that transient exposure to IFN-γ stimulation induces a long-term desensitisation of STAT1 signalling and gene expression responses, revealing a dose- and time-dependent regulatory feedback that controls JAK-STAT responses upon re-exposure to stimulus. We show that IFN-α/β1 elicit different level of desensitisation from IFN-γ, where cells refractory to IFN-α/β1 are sensitive to IFN-γ, but not vice versa. We experimentally demonstrate that the underlying feedback mechanism involves regulation of STAT1 phosphorylation but is independent of new mRNA synthesis and cognate receptor expression. A new feedback model of the protein tyrosine phosphatase activity recapitulates experimental data and demonstrates JAK-STAT network’s ability to decode relative changes of dose, timing, and type of temporal interferon stimulation. These findings reveal that STAT desensitisation renders cells with signalling memory of type I and II interferon stimulation, which in the future may improve administration of interferon therapy.

TYK2 in Immune Responses and Treatment of Psoriasis

Tyrosine kinase 2 (TYK2), a key part of the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway, plays an integral role in the differentiation and immune responses of intrinsic immune cells and regulates the mediation of cytokines. TYK2 leads to inflammatory cascade responses in the pathogenesis of immune-mediated inflammatory diseases (IMIDs), especially psoriasis. Small-molecule TYK2 inhibitors are considered to be an effective strategy for modulating psoriasis. Here, we attempt to review the pro-inflammatory mechanisms of the JAK-STAT signaling pathway, the regulatory roles of TYK2 in the pathogenesis of psoriasis, and provide updates on ongoing and recently completed trials of TYK2 inhibitors.

Managing Cancer Drug Resistance from the Perspective of Inflammation

The development of multidrug resistance in cancer chemotherapy is a major obstacle to the effective treatment of human malignant tumors. Several epidemiological studies have demonstrated that inflammation is closely related to cancer and plays a key role in the development of both solid and liquid tumors. Therefore, targeting inflammation and the molecules involved in the inflammatory process may be a good strategy for treating drug-resistant tumors. In this review, we discuss the molecular mechanisms underlying inflammation in regulating anticancer drug resistance by modulating drug action and drug-mediated cell death pathways. Inflammation alters the effectiveness of drugs through modulation of the expression of multidrug efflux transporters (e.g., ABCG2, ABCB1, and ABCC1) and drug-metabolizing enzymes (e.g., CYP1A2 and CYP3A4). In addition, inflammation can protect cancer cells from drug-mediated cell death by regulating DNA damage repair, downstream adaptive response (e.g., apoptosis, autophagy, and oncogenic bypass signaling), and tumor microenvironment. Intriguingly, manipulating inflammation may affect drug resistance through various molecular mechanisms validated by in vitro/in vivo models. In this review, we aim to summarize the underlying molecular mechanisms that inflammation participates in cancer drug resistance and discuss the potential clinical strategies targeting inflammation to overcome drug resistance.

One of the active ingredients in Paeoniae Radix Alba functions as JAK1 inhibitor in rheumatoid arthritis

Objective: We aimed to explore and verify the mechanism underlying the action of the active ingredients of Paeoniae Radix Alba (PRA) in the treatment of rheumatoid arthritis (RA).

Methods: The protein targets of PRA’s six active ingredients and RA were identified. Then, the intersection of the two groups was studied. The drug–target network was constructed, visualized, and analyzed by Cytoscape software. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment were performed to analyze these genes. Furthermore, we validated our predictions of the potential targets through a docking study. Finally, the anti-inflammatory effect of Palbinone (PB), one of the active ingredients of PRA, was tested by conducting in vitro and in vivo studies.

Results: Six active ingredients of PRA were identified, and 103 overlapping genes were discovered. Functional enrichment analysis indicated that the genes are mostly enriched in IL-17 signaling pathway, Th17 cell differentiation, and the FoxO, ErbB, and TNF signaling pathways. 10 hub genes and two gene cluster modules were identified by Cytoscape. Molecular docking analysis proved that PB was able to bind to the ATP binding site of Janus kinase (JAK)1, thereby acting as a potential inhibitor of JAK1. In vitro and in vivo studies demonstrated that PB exerts its anti-inflammatory role via the inhibition of JAK1.

Conclusion: We constructed a multitarget pharmacological network of PRA in RA treatment. PB, one of the active compounds of PRA, was demonstrated to be a promising inhibitor of JAK1.

Defining and targeting patterns of T cell dysfunction in inborn errors of immunity

Inborn errors of immunity (IEIs) are a group of more than 450 monogenic disorders that impair immune development and function. A subset of IEIs blend increased susceptibility to infection, autoimmunity, and malignancy and are known collectively as primary immune regulatory disorders (PIRDs). While many aspects of immune function are altered in PIRDs, one key impact is on T-cell function. By their nature, PIRDs provide unique insights into human T-cell signaling; alterations in individual signaling molecules tune downstream signaling pathways and effector function. Quantifying T-cell dysfunction in PIRDs and the underlying causative mechanisms is critical to identifying existing therapies and potential novel therapeutic targets to treat our rare patients and gain deeper insight into the basic mechanisms of T-cell function. Though there are many types of T-cell dysfunction, here we will focus on T-cell exhaustion, a key pathophysiological state. Exhaustion has been described in both human and mouse models of disease, where the chronic presence of antigen and inflammation (e.g., chronic infection or malignancy) induces a state of altered immune profile, transcriptional and epigenetic states, as well as impaired T-cell function. Since a subset of PIRDs amplify T-cell receptor (TCR) signaling and/or inflammatory cytokine signaling cascades, it is possible that they could induce T-cell exhaustion by genetically mimicking chronic infection. Here, we review the fundamentals of T-cell exhaustion and its possible role in IEIs in which genetic mutations mimic prolonged or amplified T-cell receptor and/or cytokine signaling. Given the potential insight from the many forms of PIRDs in understanding T-cell function and the challenges in obtaining primary cells from these rare disorders, we also discuss advances in CRISPR-Cas9 genome-editing technologies and potential applications to edit healthy donor T cells that could facilitate further study of mechanisms of immune dysfunctions in PIRDs. Editing T cells to match PIRD patient genetic variants will allow investigations into the mechanisms underpinning states of dysregulated T-cell function, including T-cell exhaustion.

Tumor-derived exosomes deliver the tumor suppressor miR-3591-3p to induce M2 macrophage polarization and promote glioma progression

Exosomes can selectively secrete harmful metabolic substances from cells to maintain cellular homeostasis, and complex crosstalk occurs between exosomes and tumor-associated macrophages (TAMs) in the glioma immune microenvironment. However, the precise mechanisms by which these exosome-encapsulated cargos create an immunosuppressive microenvironment remain unclear. Herein, we investigated the effect of glioma-derived exosomes (GDEs) on macrophage polarization and glioma progression. We performed sequencing analysis of cerebrospinal fluid (CSF) and tumor tissues from glioma patients to identify functional microRNAs (miRNAs). High levels of miR-3591-3p were found in CSF and GDEs but not in normal brain tissue or glial cells. Functionally, GDEs and miR-3591-3p significantly induced M2 macrophage polarization and increased the secretion of IL10 and TGFβ1, which in turn promoted glioma invasion and migration. Moreover, miR-3591-3p overexpression in glioma cell lines resulted in G2/M arrest and markedly increased apoptosis. Mechanistically, miR-3591-3p can directly target CBLB and MAPK1 in macrophages and glioma cells, respectively, and further activate the JAK2/PI3K/AKT/mTOR, JAK2/STAT3, and MAPK signaling pathways. In vivo experiments confirmed that macrophages lentivirally transduced with miR-3591-3p can significantly promote glioma progression. Thus, our study demonstrates that tumor-suppressive miR-3591-3p in glioma cells can be secreted via exosomes and target TAMs to induce the formation of an immunosuppressive microenvironment. Collectively, these findings provide new insights into the role of glioma exosomal miRNAs in mediating the establishment of an immunosuppressive tumor microenvironment and show that miR-3591-3p may be a valuable biomarker and that blocking the encapsulation of miR-3591-3p into exosomes may become a novel immunotherapeutic strategy for glioma.

Biomarker Genes Discovery of Alzheimer’s Disease by Multi-Omics-Based Gene Regulatory Network Construction of Microglia

Microglia, the major immune cells in the brain, mediate neuroinflammation, increased oxidative stress, and impaired neurotransmission in Alzheimer’s disease (AD), in which most AD risk genes are highly expressed. In microglia, due to the limitations of current single-omics data analysis, risk genes, the regulatory mechanisms, the mechanisms of action of immune responses and the exploration of drug targets for AD immunotherapy are still unclear. Therefore, we proposed a method to integrate multi-omics data based on the construction of gene regulatory networks (GRN), by combining weighted gene co-expression network analysis (WGCNA) with single-cell regulatory network inference and clustering (SCENIC). This enables snRNA-seq data and bulkRNA-seq data to obtain data on the deeper intermolecular regulatory relationships, related genes, and the molecular mechanisms of immune-cell action. In our approach, not only were central transcription factors (TF) STAT3, CEBPB, SPI1, and regulatory mechanisms identified more accurately than with single-omics but also immunotherapy targeting central TFs to drugs was found to be significantly different between patients. Thus, in addition to providing new insights into the potential regulatory mechanisms and pathogenic genes of AD microglia, this approach can assist clinicians in making the most rational treatment plans for patients with different risks; it also has significant implications for identifying AD immunotherapy targets and targeting microglia-associated immune drugs.

Gene expression profiling after ochratoxin A treatment in small intestinal epithelial cells from pigs

Ochratoxin A (OTA) is a well-known mycotoxin that causes disease through the ingestion of contaminated food or feed, for example, in the porcine industry. The intestinal epithelium acts as the first barrier against food contamination. We conducted a study on the exposure of the porcine intestinal epithelium to OTA. We used the intestinal porcine epithelial cell line IPEC-J2 as an in vitro model to evaluate the altered molecular mechanisms following OTA exposure. Gene expression profiling revealed that OTA upregulated 782 genes and downregulated 896, totalling 1678 differentially expressed genes. Furthermore, immunofluorescence, quantitative real-time polymerase chain reaction, and western blotting confirmed that OTA damages the tight junction protein ZO-1. Moreover, OTA activated the expression of inflammatory genes (IL-6, IL-8, IL-10, NF-kB, TLR4, and TNF-α). In summary, this study confirmed that OTA alters various molecular mechanisms and has several adverse effects on IPEC-J2 cells.

Chromatin remodeling (SWI/SNF) complexes, cancer, and response to immunotherapy

Chromatin regulation involves four subfamilies composed of ATP-dependent multifunctional protein complexes that remodel the way DNA is packaged. The SWItch/Sucrose Non-Fermentable (SWI/SNF) chromatin remodeling complex subfamily mediates nucleosome reorganization and hence activation/repression of critical genes. The SWI/SNF complex is composed of the BRG-/BRM-associated factor and Polybromo-associated BAF complexes, which in turn have multiple subunits. Significantly, ~20% of malignancies harbor alterations in >1 of these subunits, making the genes encoding SWI/SNF family members among the most vulnerable to genomic aberrations in cancer. ARID1A is the largest subunit of the SWI/SNF complex and is altered in ~40%–50% of ovarian clear cell cancers and ~15%–30% of cholangiocarcinomas, in addition to a variety of other malignancies. Importantly, outcome was improved after immune checkpoint blockade (ICB) in patients with ARID1A-altered versuss wild-type tumors, and this result was independent of microsatellite instability or tumor mutational burden. Another subunit—PBRM1—is mutated in ~40% of clear cell renal cell carcinomas and ~12% of cholangiocarcinomas; there are contradictory reports regarding ICB responsiveness. Two other SWI/SNF subunits of interest are SMARCA4 and SMARCB1. SMARCA4 loss is the hallmark of small cell carcinoma of the ovary hypercalcemic type (and is found in a variety of other malignancies); SMARCA4 germline alterations lead to rhabdoid tumor predisposition syndrome-2; SMARCB1 germline alterations, rhabdoid tumor predisposition syndrome-1. Remarkable, although anecdotal, responses to ICB have been reported in both SMARCA4-aberrant and SMARCB1-aberrant advanced cancers. This review focuses on the role that SWI/SNF chromatin remodeling subunits play in carcinogenesis, the immune microenvironment, and in immunotherapy responsiveness.

Randomized, double-blinded, placebo-controlled phase I study of the pharmacokinetics, pharmacodynamics, and safety of KL130008, a novel oral JAK inhibitor, in healthy subjects

BACKGROUND AND OBJECTIVES

KL130008 is a novel selective inhibitor of Janus kinase (JAK) 1/2 that may have therapeutic benefit against rheumatoid arthritis (RA) and other autoimmune diseases. Here, we developed a first-in-human trial of KL130008 to evaluate its pharmacokinetics (PK), pharmacodynamics (PD), and safety in healthy subjects.

METHODS

Randomized, double-blinded, placebo-controlled phase I study was designed. Healthy Chinese subjects received KL130008 in single-ascending doses (1-20 mg) or multiple-ascending doses (2-6 mg) once daily for seven days, and data on PK, PD, and safety data including QT interval were evaluated.

RESULTS

A total of 79 subjects were enrolled, of whom 77 completed the study. After oral administration following at least a 10-h fast, KL130008 was rapidly absorbed and reached a maximum concentration (C_max) in 0.6-1.5 h. KL130008 exposure was approximately linear and dose-proportional. The drug showed exponential elimination with t_1/2 = 14-18 h, and 8-20% of KL130008 was excreted in the urine. Dose-dependent inhibition of the phosphorylated signal transduction and transcriptional activator 3 (p-STAT3) was observed in subjects who received single KL130008 doses of 4-20 mg, while multiple dosing of KL130008 at 2, 4, or 6 mg once daily for seven consecutive days sustainably inhibited p-STAT3. The rates of treatment-emergent adverse events were 88.7% with KL130008 and 81.3% with placebo. All such events were grade 1 or 2 and disappeared or resolved by the end of the study. The most frequent such events were a decrease in neutrophil percentage, which occurred in 30.6% of subjects on KL130008; a decrease in neutrophil count, which occurred in 29.0% of subjects on KL130008; and an increase in lymphocyte percentage, which occurred in 25.8% of subjects on KL130008. None of these three events occurred while subjects were on placebo.

CONCLUSION

Our results support that KL130008 is a safe and well-tolerated oral JAK1/2 inhibitor. The present study may help optimize the KL130008 dosing regimen for a phase II study.

CLINICAL TRIAL REGISTRATION NUMBER

ChiCTR1800018743 (chictr.org); registered on October 7, 2018.

Cytokine Receptor Diversity in the Lamprey Predicts the Minimal Essential Cytokine Networks of Vertebrates

The vertebrate adaptive immune systems (Agnatha and Gnathostomata) use sets of T and B lymphocyte lineages that somatically generate highly diverse repertoires of Ag-specific receptors and Abs. In Gnathostomata, cytokine networks regulate the activation of lymphoid and myeloid cells, whereas little is known about these components in Agnathans. Most gnathostome cytokines are four-helix bundle cytokines with poorly conserved primary sequences. In contrast, sequence conservation across bilaterians has been observed for cognate cytokine receptor chains, allowing their structural classification into two classes, and for downstream JAK/STAT signaling mediators. With conserved numbers among Gnathostomata, human cytokine receptor chains (comprising 34 class I and 12 class II) are able to interact with 28 class I helical cytokines (including most ILs) and 16 class II cytokines (including all IFNs), respectively. Hypothesizing that the arsenal of cytokine receptors and transducers may reflect homologous cytokine networks, we analyzed the lamprey genome and transcriptome to identify genes and transcripts for 23 class I and five class II cytokine receptors alongside one JAK signal mediator and four STAT transcription factors. On the basis of deduction of their respective orthologs, we predict that these receptors may interact with 16 class I and 3 class II helical cytokines (including IL-4, IL-6, IL-7, IL-12, IL-10, IFN-γ, and thymic stromal lymphoprotein homologs). On the basis of their respective activities in mammals, this analysis suggests the existence of lamprey cytokine networks that may regulate myeloid and lymphoid cell differentiation, including potential Th1/Th2 polarization. The predicted networks thus appear remarkably homologous to those of Gnathostomata, albeit reduced to essential functions.

Immunotherapy in atopic dermatitis

In the past decade, the emergence of biologics targeting human cytokine networks has advanced a new era in atopic dermatitis therapy. Dupilumab, in particular, the most widely studied and used IL-4/IL-13 inhibitor, has been considered a milestone in the treatment of patients with moderate-to-severe atopic dermatitis. In addition to the IL-4 and IL-13 pathways, many other cytokines and receptors have been newly targeted as therapeutic options. In this review, the authors provide an overview of the approved and tested biologics and JAK inhibitors for the treatment of atopic dermatitis, including their advantages and limitations.

The RING finger protein family in health and disease

Ubiquitination is a highly conserved and fundamental posttranslational modification (PTM) in all eukaryotes regulating thousands of proteins. The RING (really interesting new gene) finger (RNF) protein, containing the RING domain, exerts E3 ubiquitin ligase that mediates the covalent attachment of ubiquitin (Ub) to target proteins. Multiple reviews have summarized the critical roles of the tripartite-motif (TRIM) protein family, a subgroup of RNF proteins, in various diseases, including cancer, inflammatory, infectious, and neuropsychiatric disorders. Except for TRIMs, since numerous studies over the past decades have delineated that other RNF proteins also exert widespread involvement in several diseases, their importance should not be underestimated. This review summarizes the potential contribution of dysregulated RNF proteins, except for TRIMs, to the pathogenesis of some diseases, including cancer, autoimmune diseases, and neurodegenerative disorder. Since viral infection is broadly involved in the induction and development of those diseases, this manuscript also highlights the regulatory roles of RNF proteins, excluding TRIMs, in the antiviral immune responses. In addition, we further discuss the potential intervention strategies targeting other RNF proteins for the prevention and therapeutics of those human diseases.