The JAK-binding protein JAB inhibits Janus tyrosine kinase activity through binding in the activation loop

Baicalin reduces inflammation to inhibit lung cancer via targeting SOCS1/NF-κB/STAT3 axis

Inflammation affects several aspects of lung cancer progression including cell proliferation, metastasis, apoptosis, angiogenesis, and drug resistance. Baicalin, an active component of Scutellaria baicalensis Georgi, exhibits anticancer activity in various cancers. However, the effects of baicalin on lung cancer and the underlying molecular mechanisms remain largely unknown. This study is to explore the effect and mechanism of baicalin on lung cancer cell A549 and urethane-induced mouse lung cancer. A cell viability assay, colony formation assay, wound healing assay, acridine orange/ethidium bromide (AO/EB) staining assay, Western blot assay, urethane-induced mouse lung cancer model, hematoxylin and eosin (HE) staining, immunohistochemistry (IHC), and ELISA assay were performed to investigate the effects of baicalin on lung cancer in vitro and in vivo. Network pharmacology analysis, molecular docking, gene silencing assays, and LPS-induced inflammation model were utilized to explore the molecular mechanisms underlying the effect of baicalin on lung cancer. Baicalin showed significant anti-proliferative, anti-migratory, anti-inflammatory and pro-apoptotic effects in vitro; it also inhibited the progression of urethane-induced mouse lung cancer in vivo. Mechanistically, suppressor of cytokine signaling 1 (SOCS1) was the key determinant for baicalin-induced inhibition of lung cancer. Baicalin increased SOCS1 expression to inactivate the NF-κB/STAT3 pathway to inhibit lung cancer in vitro and in vivo. Taken together, baicalin reduces inflammation to inhibit lung cancer via targeting SOCS1/NF-κB/STAT3 axis, providing a prospective compound and novel target for lung cancer treatment.

JAK/STAT3 signaling in cardiac fibrosis: a promising therapeutic target

Cardiac fibrosis is a serious health problem because it is a common pathological change in almost all forms of cardiovascular diseases. Cardiac fibrosis is characterized by the transdifferentiation of cardiac fibroblasts (CFs) into cardiac myofibroblasts and the excessive deposition of extracellular matrix (ECM) components produced by activated myofibroblasts, which leads to fibrotic scar formation and subsequent cardiac dysfunction. However, there are currently few effective therapeutic strategies protecting against fibrogenesis. This lack is largely because the molecular mechanisms of cardiac fibrosis remain unclear despite extensive research. The Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling cascade is an extensively present intracellular signal transduction pathway and can regulate a wide range of biological processes, including cell proliferation, migration, differentiation, apoptosis, and immune response. Various upstream mediators such as cytokines, growth factors and hormones can initiate signal transmission via this pathway and play corresponding regulatory roles. STAT3 is a crucial player of the JAK/STAT pathway and its activation is related to inflammation, malignant tumors and autoimmune illnesses. Recently, the JAK/STAT3 signaling has been in the spotlight for its role in the occurrence and development of cardiac fibrosis and its activation can promote the proliferation and activation of CFs and the production of ECM proteins, thus leading to cardiac fibrosis. In this manuscript, we discuss the structure, transactivation and regulation of the JAK/STAT3 signaling pathway and review recent progress on the role of this pathway in cardiac fibrosis. Moreover, we summarize the current challenges and opportunities of targeting the JAK/STAT3 signaling for the treatment of fibrosis. In summary, the information presented in this article is critical for comprehending the role of the JAK/STAT3 pathway in cardiac fibrosis, and will also contribute to future research aimed at the development of effective anti-fibrotic therapeutic strategies targeting the JAK/STAT3 signaling.

A newly identified 45-kDa JAK2 variant with an altered kinase domain structure represents a novel mode of JAK2 kinase inhibitor resistance

Tyrosine-protein kinase (janus kinase; JAK)-signal transducer and activator of transcription (STAT) signaling plays a pivotal role in the development of myeloproliferative neoplasms (MPNs). Treatment with the potent JAK1/JAK2-specific inhibitor, ruxolitinib, significantly reduces tumor burden; however, ruxolitinib treatment does not fully eradicate the malignant clone. As the molecular basis for the disease persistence is not well understood, we set out to gain new insights by generating ruxolitinib-resistant cell lines. Surprisingly, these cells harbor a 45 kDa JAK2 variant (FERM-JAK2) consisting of the N-terminal FERM domain directly fused to the C-terminal kinase domain in 80% of sublines resistant to ruxolitinib. At the molecular level, FERM-JAK2 is able to directly bind and activate STAT5 in the absence of cytokine receptors. Furthermore, phosphorylation of activation-loop tyrosines is dispensable for FERM-JAK2-mediated STAT5 activation and cellular transformation, in contrast to JAK2-V617F. As a result, FERM-JAK2 is highly resistant to several ATP-competitive JAK2 inhibitors, whereas it is particularly sensitive to HSP90 inhibition. A murine model of FERM-JAK2 leukemogenesis showed an accelerated MPN phenotype with pronounced splenomegaly. Notably, most current protocols for the monitoring of emerging JAK variants are unable to detect FERM-JAK2, highlighting the urgent need for implementing next-generation sequencing approaches in MPN patients receiving ruxolitinib.

Agent-based vs. equation-based multi-scale modeling for macrophage polarization

Macrophages show high plasticity and result in heterogenic subpopulations or polarized states identified by specific cellular markers. These immune cells are typically characterized as pro-inflammatory, or classically activated M1, and anti-inflammatory, or alternatively activated M2. However, a more precise definition places them along a spectrum of activation where they may exhibit a number of pro- or anti-inflammatory roles. To understand M1-M2 dynamics in the context of a localized response and explore the results of different mathematical modeling approaches based on the same biology, we utilized two different modeling techniques, ordinary differential equation (ODE) modeling and agent-based modeling (ABM), to simulate the spectrum of macrophage activation to general pro- and anti-inflammatory stimuli on an individual and multi-cell level. The ODE model includes two hallmark pro- and anti-inflammatory signaling pathways and the ABM incorporates similar M1-M2 dynamics but in a spatio-temporal platform. Both models link molecular signaling with cellular-level dynamics. We then performed simulations with various initial conditions to replicate different experimental setups. Similar results were observed in both models after tuning to a common calibrating experiment. Comparing the two models' results sheds light on the important features of each modeling approach. When more data is available these features can be considered when choosing techniques to best fit the needs of the modeler and application.

The Rax homeoprotein in Müller glial cells is required for homeostasis maintenance of the postnatal mouse retina

Müller glial cells, which are the most predominant glial subtype in the retina, play multiple important roles, including the maintenance of structural integrity, homeostasis, and physiological functions of the retina. We have previously found that the Rax homeoprotein is expressed in postnatal and mature Müller glial cells in the mouse retina. However, the function of Rax in postnatal and mature Müller glial cells remains to be elucidated. In the current study, we first investigated Rax function in retinal development using retroviral lineage analysis and found that Rax controls the specification of late-born retinal cell types, including Müller glial cells in the postnatal retina. We next generated Rax tamoxifen-induced conditional KO (Rax iCKO) mice, where Rax can be depleted in mTFP-labeled Müller glial cells upon tamoxifen treatment, by crossing Raxflox/flox mice with Rlbp1-CreERT2 mice, which we have produced. Immunohistochemical analysis showed a characteristic of reactive gliosis and enhanced gliosis of Müller glial cells in Rax iCKO retinas under normal and stress conditions, respectively. We performed RNA-seq analysis on mTFP-positive cells purified from the Rax iCKO retina and found significantly reduced expression of suppressor of cytokinesignaling-3 (Socs3). Reporter gene assays showed that Rax directly transactivates the Socs3 promoter. We observed decreased expression of Socs3 in Müller glial cells of Rax iCKO retinas by immunostaining. Taken together, the present results suggest that Rax suppresses inflammation in Müller glial cells by transactivating Socs3. This study sheds light on the transcriptional regulatory mechanisms underlying retinal Müller glial cell homeostasis.

Suppressor of Cytokine Signaling 1 Haploinsufficiency: A New Driver of Autoimmunity and Immunodysregulation

Suppressor of cytokine signaling 1 (SOCS1) is a negative regulator of cytokine signaling that inhibits the activation of Janus kinases. A human disease caused by SOCS1 haploinsufficiency was first identified in 2020. To date, 18 cases of SOCS1 haploinsufficiency have been described. These patients experience enhanced activation of leukocytes and multiorgan system immunodysregulation, with immune-mediated cytopenia as the most common feature. In this review, the authors provide an overview on the biology of SOCS1 and summarize their knowledge of SOCS1 haploinsufficiency including genetics and clinical manifestations. They discuss the available treatment experience and outline an approach for the evaluation of suspected cases.

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.

KIAA0317 regulates SOCS1 stability to ameliorate colonic inflammation

Dysregulated cytokine signalling is a hallmark of inflammatory bowel diseases. Inflammatory responses of the colon are regulated by the suppressor of cytokine signalling (SOCS) proteins. SOCS1 is a key member of this family, and its function is critical in maintaining an appropriate inflammatory response through the JAK/STAT signalling pathway. Dysregulation of SOCS1 protein has been identified as a causal element in colonic inflammatory diseases. Despite this, it remains unclear how SOCS1 protein is regulated. Here, we identify that SOCS1 protein is targeted for degradation by the ubiquitin proteasome system, mediated by the E3 ubiquitin ligase KIAA0317 during experimental colonic inflammation. We characterize the mechanism of protein-protein interaction and ubiquitin conjugation to SOCS1 and demonstrate that the modulation of SOCS1 protein level leads to stark effects on JAK/STAT inflammatory signalling. Together, these results provide insight into the regulation of colonic inflammation through a new mechanism of ubiquitin-based control of SOCS1 protein.

JAK/STAT Signaling and Cervical Cancer: From the Cell Surface to the Nucleus

The Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway constitutes a rapid signaling module from the cell surface to the nucleus, and activates different cellular responses, such as proliferation, survival, migration, invasion, and inflammation. When the JAK/STAT pathway is altered, it contributes to cancer progression and metastasis. STAT proteins play a central role in developing cervical cancer, and inhibiting the JAK/STAT signaling may be necessary to induce tumor cell death. Several cancers show continuous activation of different STATs, including cervical cancer. The constitutive activation of STAT proteins is associated with a poor prognosis and overall survival. The human papillomavirus (HPV) oncoproteins E6 and E7 play an essential role in cervical cancer progression, and they activate the JAK/STAT pathway and other signals that induce proliferation, survival, and migration of cancer cells. Moreover, there is a crosstalk between the JAK/STAT signaling cascade with other signaling pathways, where a plethora of different proteins activate to induce gene transcription and cell responses that contribute to tumor growth. Therefore, inhibition of the JAK/STAT pathway shows promise as a new target in cancer treatment. In this review, we discuss the role of the JAK/STAT pathway components and the role of the HPV oncoproteins associated with cellular malignancy through the JAK/STAT proteins and other signaling pathways to induce tumor growth.

JAKs and STATs from a Clinical Perspective: Loss-of-Function Mutations, Gain-of-Function Mutations, and Their Multidimensional Consequences

The JAK/STAT signaling pathway plays a key role in cytokine signaling and is involved in development, immunity, and tumorigenesis for nearly any cell. At first glance, the JAK/STAT signaling pathway appears to be straightforward. However, on closer examination, the factors influencing the JAK/STAT signaling activity, such as cytokine diversity, receptor profile, overlapping JAK and STAT specificity among non-redundant functions of the JAK/STAT complexes, positive regulators (e.g., cooperating transcription factors), and negative regulators (e.g., SOCS, PIAS, PTP), demonstrate the complexity of the pathway's architecture, which can be quickly disturbed by mutations. The JAK/STAT signaling pathway has been, and still is, subject of basic research and offers an enormous potential for the development of new methods of personalized medicine and thus the translation of basic molecular research into clinical practice beyond the use of JAK inhibitors. Gain-of-function and loss-of-function mutations in the three immunologically particularly relevant signal transducers STAT1, STAT3, and STAT6 as well as JAK1 and JAK3 present themselves through individual phenotypic clinical pictures. The established, traditional paradigm of loss-of-function mutations leading to immunodeficiency and gain-of-function mutation leading to autoimmunity breaks down and a more differentiated picture of disease patterns evolve. This review is intended to provide an overview of these specific syndromes from a clinical perspective and to summarize current findings on pathomechanism, symptoms, immunological features, and therapeutic options of STAT1, STAT3, STAT6, JAK1, and JAK3 loss-of-function and gain-of-function diseases.

The SOCS1 KIR and SH2 domain are both required for suppression of cytokine signaling in vivo

Suppressor Of Cytokine Signaling (SOCS) 1 is a critical negative regulator of cytokine signaling and required to protect against an excessive inflammatory response. Genetic deletion of Socs1 results in unrestrained cytokine signaling and neonatal lethality, characterised by an inflammatory immune infiltrate in multiple organs. Overexpression and structural studies have suggested that the SOCS1 kinase inhibitory region (KIR) and Src homology 2 (SH2) domain are important for interaction with and inhibition of the receptor-associated JAK1, JAK2 and TYK2 tyrosine kinases, which initiate downstream signaling. To investigate the role of the KIR and SH2 domain in SOCS1 function, we independently mutated key conserved residues in each domain and analysed the impact on cytokine signaling, and the in vivo impact on SOCS1 function. Mutation of the SOCS1-KIR or SH2 domain had no impact on the integrity of the SOCS box complex, however, mutation within the phosphotyrosine binding pocket of the SOCS1-SH2 domain specifically disrupted SOCS1 interaction with phosphorylated JAK1. In contrast, mutation of the KIR did not affect the interaction with JAK1, but did prevent SOCS1 inhibition of JAK1 autophosphorylation. In human and mouse cell lines, both mutants impacted the ability of SOCS1 to restrain cytokine signaling, and crucially, Socs1-R105A and Socs1-F59A mice displayed a neonatal lethality and excessive inflammatory phenotype similar to Socs1-null mice. This study defines a critical and non-redundant role for both the KIR and SH2 domain in endogenous SOCS1 function.

SOCS3 as a potential driver of lung metastasis in colon cancer patients

Background

The suppressor of cytokine signaling 3 (SOCS3) is the negative feedback regulator of the JAK-STAT signaling pathway. The purpose of our study was to investigate the SOCS3 status in colon primary tumor and lung metastasis and its relationship with macrophages.

Methods

The SOCS3 expression pattern and its relationship with the immune response in pan-cancer was investigated using multiple methods. Samples and corresponding clinical information of 32 colon cancer patients with lung metastasis were collected, and the CD68, CD163, and SOCS3 status were conducted using immunohistochemistry (IHC). The relationship between SOCS3 status and macrophage markers was analyzed. Besides, we explored the molecular mechanisms of SOCS3 in lung metastasis via the TCGA database.

Results

High SOCS3 expression was more inclined to poor prognosis and was positively correlated with main immune cell infiltration in almost each cancer type, especially in colon cancer. Compared with the colon primary tumor, lung metastasis harbored higher CD163 and SOCS3 expression, and high SOCS3 expression was more likely to be associated with high CD163 expression in lung metastasis. Besides, the exceptional differentially expressed genes in lung metastasis significantly enriched in immune responses and regulations.

Conclusions

SOCS3 possessed value as a prognostic marker and target for immunotherapeutic intervention in different tumors and might be a potential target of tumor progression and tumor immunotherapy in colon cancer.

Mechanism of herpesvirus protein kinase UL13 in immune escape and viral replication

Upon infection, the herpes viruses create a cellular environment suitable for survival, but innate immunity plays a vital role in cellular resistance to viral infection. The UL13 protein of herpesviruses is conserved among all herpesviruses and is a serine/threonine protein kinase, which plays a vital role in escaping innate immunity and promoting viral replication. On the one hand, it can target various immune signaling pathways in vivo, such as the cGAS-STING pathway and the NF-κB pathway. On the other hand, it phosphorylates regulatory many cellular and viral proteins for promoting the lytic cycle. This paper reviews the research progress of the conserved herpesvirus protein kinase UL13 in immune escape and viral replication to provide a basis for elucidating the pathogenic mechanism of herpesviruses, as well as providing insights into the potential means of immune escape and viral replication of other herpesviruses that have not yet resolved the function of it.

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.

Quercetin encapsulated in Folic Acid-Modified Liposomes is therapeutic against osteosarcoma by non-Covalent binding to the JH2 Domain of JAK2 Via the JAK2-STAT3-PDL1

Osteosarcoma (OS) is a malignant solid tumor prone to lung metastasis that occurs in adolescents aged 15-19 years. Neoadjuvant chemotherapy and surgical treatment aimed at curing OS have gained limited progress over the last 30 years. Exploring new effective second-line therapies for OS patients is a serious challenge for researchers. Quercetin, a multiple biologically active polyphenolic flavonoid, has been used in tumor therapy. However, the exact mechanism of quercetin is still unknown, which limits the application of quercetin. In the current study, we found that quercetin could inhibit JAK2 through the JH2 domain in a non-covalent manner, resulting in the inhibition of OS proliferation and immune escape via the JAK2-STAT3-PD-L1 signaling axis. More importantly, to overcome the shortcomings of quercetin, including low water solubility and low oral availability, we encapsulated it with folic acid-modified liposomes. The transportation of quercetin by folic acid-modified liposomes may provide a feasible strategy to cure OS.

Small Noncoding RNA (sncRNA1) within the Latency-Associated Transcript Modulates Herpes Simplex Virus 1 Virulence and the Host Immune Response during Acute but Not Latent Infection

HSV-1 latency-associated transcript (LAT) plays a major role in establishing latency and reactivation; however, the mechanism by which LAT controls these processes is largely unknown. In this study, we sought to establish the role of the small noncoding RNA1 (sncRNA1) encoded within LAT during HSV-1 ocular infection. Our results suggest that sncRNA1 has a protective role during acute ocular infection by modulating the innate immune response to infection.

Optimization of Phosphotyrosine Peptides that Target the SH2 Domain of SOCS1 and Block Substrate Ubiquitination

Suppressor of cytokine signaling 1 (SOCS1) has emerged as a potential therapeutic target in inflammatory and viral diseases. SOCS1 operates via its kinase inhibitory region, Src homology 2 (SH2) domain, and SOCS box to negatively regulate the Janus kinase/signal transducers and activators of transcription signaling pathway. In this study, we utilized native phosphotyrosine peptide substrates as a starting point to iteratively explore the requirement of each amino acid position to target the SH2 domain of SOCS1. We show that Met, Thr, Thr, Val, and Asp in the respective -1, +1, +2, +3, and +5 positions within the peptide substrate are favored for binding to the SOCS1-SH2 domain and identifying several phosphotyrosine peptides that have potent SOCS1 binding affinity with IC₅₀ values ranging from 20 to 70 nM and greater than 100-fold selectivity against the closely related SOCS family proteins, CIS, SOCS2, and SOCS3. The optimized phosphotyrosine peptide was shown to stabilize SOCS1 in a thermal shift assay using cell lysates and inhibited SOCS1-mediated ubiquitination of a target substrate in a biochemical assay. Collectively, these data provide the framework to develop cell-permeable peptidomimetics that further investigate the potential of the SOCS1-SH2 domain as a therapeutic target in inflammatory and viral diseases.

The JAK/STAT signaling pathway: from bench to clinic

The Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway was discovered more than a quarter-century ago. As a fulcrum of many vital cellular processes, the JAK/STAT pathway constitutes a rapid membrane-to-nucleus signaling module and induces the expression of various critical mediators of cancer and inflammation. Growing evidence suggests that dysregulation of the JAK/STAT pathway is associated with various cancers and autoimmune diseases. In this review, we discuss the current knowledge about the composition, activation, and regulation of the JAK/STAT pathway. Moreover, we highlight the role of the JAK/STAT pathway and its inhibitors in various diseases.

The JAK/STAT signaling pathway: from bench to clinic

The Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway was discovered more than a quarter-century ago. As a fulcrum of many vital cellular processes, the JAK/STAT pathway constitutes a rapid membrane-to-nucleus signaling module and induces the expression of various critical mediators of cancer and inflammation. Growing evidence suggests that dysregulation of the JAK/STAT pathway is associated with various cancers and autoimmune diseases. In this review, we discuss the current knowledge about the composition, activation, and regulation of the JAK/STAT pathway. Moreover, we highlight the role of the JAK/STAT pathway and its inhibitors in various diseases.

Emerging role of signal transducer and activator of transcription 3 (STAT3) in pituitary adenomas

Pituitary adenomas are benign tumours that can cause an individual various clinical manifestations including tumour mass effects and/or the diverse effects of abnormal pituitary hormone secretion. Given the morbidity and limited treatment options for pituitary adenomas, there is a need for better biomarkers and treatment options. One molecule that is of specific interest is the signal transducer and activator of transcription 3 (STAT3), a transcription factor that plays a critical role in mediating cytokine-induced changes in gene expression. In addition, STAT3 controls cell proliferation by regulating mitochondrial activity. Not only does activation of STAT3 play a crucial role in tumorigenesis, including pituitary tumorigenesis, but a number of studies also demonstrate pharmacological STAT3 inhibition as a promising treatment approach for many types of tumours, including pituitary tumours. This review will focus on the role of STAT3 in different pituitary adenomas, in particular, growth hormone-producing adenomas and null cell adenomas. Furthermore, how STAT3 is involved in the cell proliferation and hormone regulation in pituitary adenomas and its potential role as a molecular therapeutic target in pituitary adenomas will be summarized.

Optineurin modulates the maturation of dendritic cells to regulate autoimmunity through JAK2-STAT3 signaling

Optineurin (OPTN) has important functions in diverse biological processes and diseases, but its effect on dendritic cell (DC) differentiation and functionality remains elusive. Here we show that OPTN is upregulated in human and mouse DC maturation, and that deletion of Optn in mice via CD11c-Cre attenuates DC maturation and impairs the priming of CD4⁺ T cells, thus ameliorating autoimmune symptoms such as experimental autoimmune encephalomyelitis (EAE). Mechanistically, OPTN binds to the JH1 domain of JAK2 and inhibits JAK2 dimerization and phosphorylation, thereby preventing JAK2-STAT3 interaction and inhibiting STAT3 phosphorylation to suppress downstream transcription of IL-10. Without such a negative regulation, Optn-deficient DCs eventually induce an IL-10/JAK2/STAT3/IL-10 positive feedback loop to suppress DC maturation. Finally, the natural product, Saikosaponin D, is identified as an OPTN inhibitor, effectively inhibiting the immune-stimulatory function of DCs and the disease progression of EAE in mice. Our findings thus highlight a pivotal function of OPTN for the regulation of DC functions and autoimmune disorders.

Cyclophilin A is a key positive and negative feedback regulator within interleukin-6 trans-signaling pathway

Cyclophilin A (CypA), a member of the cyclophilin family, plays a vital role in microorganismal infections, inflammatory diseases, and cancers. Interleukin-6 (IL-6) is a pleiotropic cytokine, exerting variety of effects on inflammation, immune response, hematopoiesis, and tumor proliferation. Binding of IL-6 to soluble IL-6 receptor (sIL-6R) induces pro-inflammatory trans-signaling, which has been described to be stronger than anti-inflammatory classic signaling triggered by the binding of IL-6 to membrane-bound IL-6 receptor. Here we found that upon the treatment of IL-6 and sIL-6R, CypA inhibited the ubiquitination-mediated degradation of IL-6 membrane receptor gp130 and enhanced its dimerization, thereby positively regulated the IL-6 trans-signaling and increased the expression of downstream iNOS, IL-6, and CypA. Furthermore, CypA expression could be negatively regulated by suppressor of cytokine signaling 1 (SOCS1). The SH2 and Box domains of SOCS1 interacted with CypA and promoted its K48-linked ubiquitination-mediated degradation, which inhibited the IL-6 trans-signaling pathway. Collectively, our findings reveal an important role of CypA in the positive and negative feedback regulation of the IL-6 trans-signaling pathway.

Establishment of an Immune-Related Gene Signature for Risk Stratification for Patients with Glioma

Glioma is a frequently seen primary malignant intracranial tumor, characterized by poor prognosis. The study is aimed at constructing a prognostic model for risk stratification in patients suffering from glioma. Weighted gene coexpression network analysis (WGCNA), integrated transcriptome analysis, and combining immune-related genes (IRGs) were used to identify core differentially expressed IRGs (DE IRGs). Subsequently, univariate and multivariate Cox regression analyses were utilized to establish an immune-related risk score (IRRS) model for risk stratification for glioma patients. Furthermore, a nomogram was developed for predicting glioma patients' overall survival (OS). The turquoise module (cor = 0.67; P < 0.001) and its genes (n = 1092) were significantly pertinent to glioma progression. Ultimately, multivariate Cox regression analysis constructed an IRRS model based on VEGFA, SOCS3, SPP1, and TGFB2 core DE IRGs, with a C-index of 0.811 (95% CI: 0.786-0.836). Then, Kaplan-Meier (KM) survival curves revealed that patients presenting high risk had a dismal outcome (P < 0.0001). Also, this IRRS model was found to be an independent prognostic indicator of gliomas' survival prediction, with HR of 1.89 (95% CI: 1.252-2.85) and 2.17 (95% CI: 1.493-3.14) in the Cancer Genome Atlas (TCGA) and Chinese Glioma Genome Atlas (CGGA) datasets, respectively. We established the IRRS prognostic model, capable of effectively stratifying glioma population, convenient for decision-making in clinical practice.

SOCS: negative regulators of cytokine signaling for immune tolerance

Cytokines are important intercellular communication tools for immunity. Many cytokines promote gene transcription and proliferation through the JAK/STAT (Janus kinase / signal transducers and activators of transcription) and the Ras/ERK (GDP/GTP-binding rat sarcoma protein / extracellular signal-regulated kinase) pathways, and these signaling pathways are tightly regulated. The SOCS (suppressor of cytokine signaling) family are representative negative regulators of JAK/STAT-mediated cytokine signaling and regulate the differentiation and function of T cells, thus being involved in immune tolerance. Human genetic analysis has shown that SOCS family members are strongly associated with autoimmune diseases, allergy and tumorigenesis. SOCS family proteins also function as immune-checkpoint molecules that contribute to the unresponsiveness of T cells to cytokines.

SOCS3 deficiency in cardiomyocytes elevates sensitivity of ischemic preconditioning that synergistically ameliorates myocardial ischemia reperfusion injury

Ischemic preconditioning (IPC) is the most powerful endogenous cardioprotective form of cellular adaptation. However, the inhibitory or augmenting mechanism underlying cardioprotection via IPC remains largely unknown. Suppressor of cytokine signaling-3 (SOCS3) is a cytokine-inducible potent negative feedback regulator of the signal transducer and activator of transcription-3 (STAT3) signaling pathway. Here, we aimed to determine whether cardiac SOCS3 deficiency and IPC would synergistically reduce infarct size after myocardial ischemia reperfusion injury. We evaluated STAT3 activation and SOCS3 induction after ischemic conditioning (IC) using western blot analysis and real-time PCR, and found that myocardial IC alone transiently activated myocardial STAT3 and correspondingly induced SOCS3 expression in wild-type mice. Compared with wild-type mice, cardiac-specific SOCS3 knockout (SOCS3-CKO) mice showed significantly greater and more sustained IC-induced STAT3 activation. Following ischemia reperfusion, IPC substantially reduced myocardial infarct size and significantly enhanced STAT3 phosphorylation in SOCS3-CKO mice compared to in wild-type mice. Real-time PCR array analysis revealed that SOCS3-CKO mice after IC exhibited significantly increased expressions of several anti-apoptotic genes and SAFE pathway-related genes. Moreover, real-time PCR analysis revealed that myocardial IC alone rapidly induced expression of the STAT3-activating cytokine erythropoietin in the kidney at 1 h post-IC. We also found that the circulating erythropoietin level was promptly increased at 1 h after myocardial IC. Myocardial SOCS3 deficiency and IPC exert synergistic effects in the prevention of myocardial injury after ischemia reperfusion. Our present results suggest that myocardial SOCS3 is a potent inhibitor of IPC-induced cardioprotection, and that myocardial SOCS3 inhibition augment IPC-mediated cardioprotection during ischemia reperfusion injury.

Ginseng leaf extract ameliorates the survival of endotoxemic mice by inhibiting the release of high mobility group box 1

High mobility group box 1 (HMGB1) is a well-defined mediator involved in the pathophysiologic response to endotoxemia and sepsis. However, the mechanisms and therapeutic agents that could prevent its release are not fully elucidated. Here, the present study demonstrates that the ginseng leaf extract (GLE) regulates lipopolysaccharide (LPS)-triggered release of HMGB1 in macrophages and endotoxemic animal model. Treatment of RAW264.7 macrophages with GLE significantly inhibited the release of HMGB1 stimulated by LPS. GLE also suppressed the generation of nitric oxide (NO) and expression of inducible NO synthase (iNOS) in a dose-dependent manner. These effects of GLE were accompanied by inhibition of HMGB1 release stimulated by LPS, indicating a potential mechanism by which GLE regulates HMGB1 release through NO signaling. Furthermore, induction of suppressor of cytokine signaling 1 by GLE-mediated GLE-dependent suppression of HMGB1 release and NO/iNOS induction by inhibiting Janus kinase 2/signal transducer and activator of transcription 1 signal in RAW 264.7 cells exposed to LPS. Finally, administration of the GLE ameliorated the survival rate of LPS-injected endotoxemic mice in a NO-dependent manner. Thus, GLE may block the LPS-stimulated release of HMGB1 by regulating cellular signal networks, thereby providing a therapeutic strategy for endotoxemia as a functional food. PRACTICAL APPLICATIONS: High mobility group box 1 (HMGB1) is released into the extracellular milieu when immune cells are exposed to pathogen-related molecules such as lipopolysaccharide (LPS), in which it acts as a critical mediator of lethality in sepsis and endotoxemia. The extract of ginseng leaf, which is a part that can be easily thrown away, ameliorated the survival rate of endotoxemic mice by inhibiting HMGB1 secretion in a NO-dependent manner. Thus, this study suggests that ginseng leaf can be used as a functional food by resolving the immune responses in the pathology of endotoxemia.

Patient-derived xenograft: a developing tool for screening biomarkers and potential therapeutic targets for human esophageal cancers

Esophageal cancer (EC) represents a human malignancy, diagnosed often at the advanced stage of cancer and resulting in high morbidity and mortality. The development of precision medicine allows for the identification of more personalized therapeutic strategies to improve cancer treatment. By implanting primary cancer tissues into immunodeficient mice for expansion, patient-derived xenograft (PDX) models largely maintain similar histological and genetic representations naturally found in patients' tumor cells. PDX models of EC (EC-PDX) provide fine platforms to investigate the tumor microenvironment, tumor genomic heterogeneity, and tumor response to chemoradiotherapy, which are necessary for new drug discovery to combat EC in addition to optimization of current therapeutic strategies for EC. In this review, we summarize the methods used for establishing EC-PDX models and investigate the utilities of EC-PDX in screening predictive biomarkers and potential therapeutic targets. The challenge of this promising research tool is also discussed.

Dynamics of rumen gene expression, microbiome colonization, and their interplay in goats

Background

Preweaned rumen development is vital for animal health and efficient fermentation. In this study, we integrated ruminal transcriptomic and metagenomic data to explore the dynamics of rumen functions, microbial colonization, and their functional interactions during the first 8 weeks of life in goats.

Results

The dynamic rumen transcriptomic and microbial profiles both exhibited two distinct phases during early rumen development. The differentially expressed genes of the rumen transcriptome between the two phases showed that the immune-related response was enriched in the first phase and nutrient-related metabolism was enriched in the second phase, whereas the differentially expressed genes of the rumen microbiome were enriched in bacteriocin biosynthesis and glycolysis/gluconeogenesis activities. The developmental shift in the rumen transcriptome (at d 21) was earlier than the feed stimulus (at d 25) and the shift in the rumen microbiome (at d 42). Additionally, 15 temporal dynamic rumen gene modules and 20 microbial modules were revealed by coexpression network analysis. Functional correlations between the rumen and its microbiome were primarily involved in rumen pH homeostasis, nitrogen metabolism and the immune response. Rumen gene modules associated with the microbial alpha diversity index were also enriched in the immune response process.

Conclusions

The present study touched the critical developmental process of rumen functions, microbial colonization and their functional interactions during preweaned development. Taken together, these results demonstrated that rumen development at the first phase is more likely a programmed process rather than stimulation from feed and the microbiome, while the shift of rumen metagenomes was likely regulated by both the diet and host. The intensive functional correlations between rumen genes and the microbiome demonstrated that synergistic processes occurred between them during early rumen development.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-021-07595-1.

Porcine reproductive and respiratory syndrome virus increases SOCS3 production via activation of p38/AP-1 signaling pathway to promote viral replication

SOCS3 belongs to the suppressor of cytokine signaling (SOCS) family, which function as negative factors in host immune responses. Prior studies have noted the importance of SOCS family proteins in immunosuppression induced by some viruses. Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most important swine-borne viruses and has threatened the global swine industry with huge economic losses since it was first described in the 1980s. PRRSV is the etiological agent of PRRS, which causes reproductive failure and respiratory disorders. PRRSV causes immunosuppression thus establishing persistent infection. In this study, it was observed that SOCS3 was upregulated in PRRSV-infected primary porcine alveolar macrophages (PAMs) and Marc-145 cells with dose-dependent effects, which depends on virus replication. Deletion of AP-1 binding motif located in SOCS3 promoter inhibited promoter activities, which indicates that AP-1 is essential for PRRSV-induced SOCS3. This result was confirmed by experiments using AP-1 inhibitor, whose pretreatment suppressed SOCS3 mRNA and protein expression. Further research showed that p38 was crucial for PRRSV-induced SOCS3 production. Importantly, SOCS3 enhanced PRRSV replication during infection. Taken together, this study indicates that PRRSV infection induced SOCS3 expression through p38/AP-1 signaling pathway. These results revealed the molecular basis of SOCS3 upregulation and would advance further understanding of the strategy for viral immune evasion.

The role of SOCS proteins in the development of virus- induced hepatocellular carcinoma

Background

Liver cancer has become one of the most common cancers and has a high mortality rate. Hepatocellular carcinoma is one of the most common liver cancers, and its occurrence and development process are associated with chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infections.

Main body

The serious consequences of chronic hepatitis virus infections are related to the viral invasion strategy. Furthermore, the viral escape mechanism has evolved during long-term struggles with the host. Studies have increasingly shown that suppressor of cytokine signaling (SOCS) proteins participate in the viral escape process. SOCS proteins play an important role in regulating cytokine signaling, particularly the Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway. Cytokines stimulate the expression of SOCS proteins, in turn, SOCS proteins inhibit cytokine signaling by blocking the JAK-STAT signaling pathway, thereby achieving homeostasis. By utilizing SOCS proteins, chronic hepatitis virus infection may destroy the host’s antiviral responses to achieve persistent infection.

Conclusions

This review provides recent knowledge regarding the role of SOCS proteins during chronic hepatitis virus infection and provides some new ideas for the future treatment of chronic hepatitis.

Microtubule-dependent mechanism of anti-inflammatory effect of SOCS1 in endothelial dysfunction and lung injury

Suppressors of cytokine signaling (SOCS) provide negative regulation of inflammatory reaction. The role and precise cellular mechanisms of SOCS1 in control of endothelial dysfunction and barrier compromise associated with acute lung injury remain unexplored. Our results show that siRNA-mediated SOCS1 knockdown augmented lipopolysaccharide (LPS)-induced pulmonary endothelial cell (EC) permeability and enhanced inflammatory response. Consistent with in vitro data, EC-specific SOCS1 knockout mice developed more severe lung vascular leak and accumulation of inflammatory cells in bronchoalveolar lavage fluid. SOCS1 overexpression exhibited protective effects against LPS-induced endothelial permeability and inflammation, which were dependent on microtubule (MT) integrity. Biochemical and image analysis of unstimulated EC showed SOCS1 association with the MT, while challenge with LPS or MT depolymerizing agent colchicine impaired this association. SOCS1 directly interacted with N2 domains of MT-associated proteins CLIP-170 and CLASP2. Furthermore, N-terminal region of SOCS1 was indispensable for these interactions and SOCS1-ΔN mutant lacking N-terminal 59 amino acids failed to rescue LPS-induced endothelial dysfunction. Depletion of endogenous CLIP-170 or CLASP2 abolished SOCS1 interaction with Toll-like receptor-4 and Janus kinase-2 leading to impairment of SOCS1 inhibitory effects on LPS-induced inflammation. Altogether, these findings suggest that endothelial barrier protective and anti-inflammatory effects of SOCS1 are critically dependent on its targeting to the MT.

SILAC proteomics implicates SOCS1 in modulating cellular macromolecular complexes and the ubiquitin conjugating enzyme UBE2D involved in MET receptor tyrosine kinase downregulation

Suppressor of Cytokine Signaling 1 (SOCS1) functions as a tumor suppressor in hepatocellular carcinoma and many other types of cancers. SOCS1 mediates its functions by inhibiting tyrosine kinases, promoting ubiquitination and proteasomal degradation of signal transducing proteins, and by modulating transcription factors. Here, we studied the impact of SOCS1 on the hepatocyte proteome using Stable Isotopic Labelling of Amino acids in Cell culture (SILAC)-based mass spectrometry on the Hepa1-6 murine HCC cell line stably expressing wildtype SOCS1 or a mutant SOCS1 with impaired SH2 domain. As SOCS1 regulates the hepatocyte growth factor (HGF) receptor, the MET receptor tyrosine kinase (RTK), the SILAC-labelled cells were stimulated or not with HGF. Following mass spectrometry analysis, differentially modulated proteins were identified, quantified and analyzed for pathway enrichment. Of the 3440 proteins identified in Hepa-SOCS1 cells at steady state, 181 proteins were significantly modulated compared to control cells. The SH2 domain mutation and HGF increased the number of differentially modulated proteins. Protein interaction network analysis revealed enrichment of SOCS1-modulated proteins within multiprotein complexes such as ubiquitin conjugating enzymes, proteasome, mRNA spliceosome, mRNA exosome and mitochondrial ribosome. Notably, the expression of UBE2D ubiquitin conjugating enzyme, which is implicated in the control of growth factor receptor tyrosine kinase signaling, was found to be regulated by SOCS1. These findings suggest that SOCS1, induced by cytokines, growth factors and diverse other stimuli, has the potential to dynamically modulate of large macromolecular regulatory complexes to help maintain cellular homeostasis.

SOCS, SPRED, and NR4a: Negative regulators of cytokine signaling and transcription in immune tolerance

Cytokines are important intercellular communication tools for immunity. Most cytokines utilize the JAK-STAT and Ras-ERK pathways to promote gene transcription and proliferation; however, this signaling is tightly regulated. The suppressor of cytokine signaling (SOCS) family and SPRED family are a representative negative regulators of the JAK-STAT pathway and the Ras-ERK pathway, respectively. The SOCS family regulates the differentiation and function of CD4⁺ T cells, CD8⁺ T cells, and regulatory T cells, and is involved in immune tolerance, anergy, and exhaustion. SPRED family proteins have been shown to inactivate Ras by recruiting the Ras-GTPase neurofibromatosis type 1 (NF1) protein. Human genetic analysis has shown that SOCS family members are strongly associated with autoimmune diseases, allergies, and tumorigenesis, and SPRED1 is involved in NF1-like syndromes and tumors. We also identified the NR4a family of nuclear receptors as a key transcription factor for immune tolerance that suppresses cytokine expression and induces various immuno-regulatory molecules including SOCS1.

Emerging roles for the IL-6 family of cytokines in pancreatic cancer

Pancreatic cancer has one of the poorest prognoses of all malignancies, with little improvement in clinical outcome over the past 40 years. Pancreatic ductal adenocarcinoma is responsible for the vast majority of pancreatic cancer cases, and is characterised by the presence of a dense stroma that impacts therapeutic efficacy and drives pro-tumorigenic programs. More specifically, the inflammatory nature of the tumour microenvironment is thought to underlie the loss of anti-tumour immunity and development of resistance to current treatments. Inflammatory pathways are largely mediated by the expression of, and signalling through, cytokines, chemokines, and other cellular messengers. In recent years, there has been much attention focused on dual targeting of cancer cells and the tumour microenvironment. Here we review our current understanding of the role of IL-6, and the broader IL-6 cytokine family, in pancreatic cancer, including their contribution to pancreatic inflammation and various roles in pancreatic cancer pathogenesis. We also summarise potential opportunities for therapeutic targeting of these pathways as an avenue towards combating poor patient outcomes.

Growth Hormone Receptor Regulation in Cancer and Chronic Diseases

The GHR signaling pathway plays important roles in growth, metabolism, cell cycle control, immunity, homeostatic processes, and chemoresistance via both the JAK/STAT and the SRC pathways. Dysregulation of GHR signaling is associated with various diseases and chronic conditions such as acromegaly, cancer, aging, metabolic disease, fibroses, inflammation and autoimmunity. Numerous studies entailing the GHR signaling pathway have been conducted for various cancers. Diverse factors mediate the up- or down-regulation of GHR signaling through post-translational modifications. Of the numerous modifications, ubiquitination and deubiquitination are prominent events. Ubiquitination by E3 ligase attaches ubiquitins to target proteins and induces proteasomal degradation or starts the sequence of events that leads to endocytosis and lysosomal degradation. In this review, we discuss the role of first line effectors that act directly on the GHR at the cell surface including ADAM17, JAK2, SRC family member Lyn, Ubc13/CHIP, proteasome, βTrCP, CK2, STAT5b, and SOCS2. Activity of all, except JAK2, Lyn and STAT5b, counteract GHR signaling. Loss of their function increases the GH-induced signaling in favor of aging and certain chronic diseases, exemplified by increased lung cancer risk in case of a mutation in the SOCS2-GHR interaction site. Insight in their roles in GHR signaling can be applied for cancer and other therapeutic strategies.

Suppressor of cytokine signaling proteins 1 and 3 and hepatitis B virus infection

Suppressor of cytokine signaling proteins (SOCS) are cytokine pathway inhibitors that play an important role in regulating the antiviral effect of interferon (IFN). Current studies have shown that SOCS1 and SOCS3 are closely related to hepatitis B virus (HBV) infection. Inhibition or stimulation of SOCS1 and SOCS3 expression may affect the antiviral effect by regulating the production of IFN, and may also affect the pathogenicity of HBV together with other cytokines or transcription regulators. This paper mainly discusses the possible mechanisms of SOCS1 and SOCS3 in HBV infection.

Expression and analysis of ESR1, IGF-1, FSH, VLDLR, LRP, LH, PRLR genes in Pekin duck and Black Muscovy duck

In order to explore the influence of egg-laying regulatory genes on egg production in ducks at different laying stages, Pekin duck and Black Muscovy duck were used in this study, including early laying stage (20-30 weeks old), peak laying period (31-48 weeks old) and late laying stage (49-66 weeks old). Relative quantitative RT-PCR was used to detect the mRNA transcription level of selected egg-laying regulatory genes in the ovary tissues of ducks at different laying stages. Study shows: during the laying period of Pekin duck, ESR1, LRP1, IGF-1 and LHR were involved in the regulation of egg-laying, and the high expression of LRP1 in the late stage could inhibit egg production. Still, the expression products of the other three genes showed promoting effect. During the laying period of Black Muscovy duck, FSH, VLDLR, IGF-1, PRLR, LHR and LRP1 participated in the regulation of egg-laying, in which the expression products of the first five genes could promote egg production, while LRP1 showed inhibitory effect. Through our experiments, these data will provide strong theoretical support for the breeding of Pekin duck and Black Muscovy duck.

LINC00669 insulates the JAK/STAT suppressor SOCS1 to promote nasopharyngeal cancer cell proliferation and invasion

Nasopharyngeal carcinoma (NPC) is an epithelial cancer emerging from the lining of nasopharyngeal mucosa, with extremely frequent occurrence in east and southeast Asia. For the purpose of exploring roles of the dysregulated long non-coding RNA (lncRNA) in NPC, we identified a novel lncRNA LINC00669 with an apparent negative correlation to the overall survival from human NPC mRNA expression profiling databases. We further performed RNA pulldown coupled with mass spectrum to find out its target protein, and applied a series of in vitro and in vivo loss-and-gain-of function assays to investigate its oncogenic roles in NPC tumor development and progression. Our results demonstrated that LINC00669 competitively binds to the key JAK/STAT signaling pathway suppressor SOCS1, and insulates it from imposing ubiquitination modification on the pathway component of STAT1, which leads to its abnormal stabilization and activation. The activated STAT1 is then transferred into the nucleus and initiates the transcription of genes related to proliferation and invasion. In summary, our study reveals that the cytoplasmic resident lncRNA LINC00669 confers malignant properties on NPC cancer cells by facilitating a persistent activation of the JAK/STAT signaling pathway. Findings in the current study shed lights on prospects for treating NPC using strategies targeting the novel regulator of the JAK/STAT signaling.

The methylation status of TNF-α and SOCS3 promoters and the regulation of these gene expressions in patients with Behçet's disease

Introduction: The aim of this study was to evaluate the methylation status of TNF-α and SOCS3 promoters in patients with BD and compare them with a healthy group.Method: This was a case-control study, in which 47 subjects with BD and 61 individuals as the control participated. Blood samples were collected from all the participants. Then, PBMCs were isolated using the Ficoll method and methylation of considered sites was investigated using the qMS-PCR technique after DNA extraction by the rapid genomic DNA extraction method and its analysis with Nano-drop.Results: The methylation and expression of TNF-α showed that the methylation level significantly declined in the patient in comparison with the healthy (p < 0.05). Moreover, the results on the mean expression showed that it significantly increased in the patient group, as compared with the healthy group (p < 0.05). In addition, the expression of the SOCS3 gene was not significantly different between the patients and healthy subjects while the level of SOCS3 methylation was significantly higher in the patient group than that in the healthy group (p < 0.05).Discussion: The present study revealed that the gene expression of TNF-alpha increased in BD patients, suggesting that TNF-alpha likely has a role in the pathogenesis of BD.

Identification of SOCS family members with prognostic values in human ovarian cancer

BACKGROUND

Suppressor of cytokine signaling (SOCS) family proteins regulate cytokine responses through inhibition of multiple signaling pathways. The expression profiles and prognostic significance of SOCS members in ovarian cancer (OC) patients still remains unclear. Here, we aimed to provide a comprehensive understanding of the prognostic values of SOCS family members in OC and to discover promising therapeutic targets for OC.

METHODS

We firstly analyzed the KEGG pathway enrichment to reveal the possible pathways associated with SOCS family. Next, we used public databases including cBioPortal, Human Protein Atlas and Oncomine to investigate genetic alterations and mRNA expression of SOCS family in OC patients. More importantly, we explored the prognostic value of each individual SOCS members in OC patients using Kaplan Meier plotter database.

RESULTS

SOCS family was markedly enriched in JAK-STAT signaling pathway. A high mutation rate in SOCSs was observed in patients with ovarian serous cancer (OSC). An increased mRNA expression of SOCS1 indicated a favorable overall survival (OS) in both OC and OSC patients, while increased SOCS5 and SOCS7 expressions were significantly associated with poorer OS. We also explored the diverse roles of SOCS members in OC patients with different clinicopathological features including grades, stages and therapies employed.

CONCLUSION

SOCS1, SOCS5 and SOCS7 may serve as prognostic biomarkers for OC patients. SOCS5 and SOCS7 may be potential therapeutic targets for OC treatment. Our results render novel insights into the association between SOCS family genes and OC development, and may highlight promising molecular targets for therapeutic interventions in OC patients.

SOCS3 is a suppressor of γc cytokine signaling and constrains generation of murine Foxp3+ regulatory T cells

SOCS3 is a cytosolic inhibitor of cytokine signaling that suppresses the activation of cytokine receptor-associated JAK kinases. Mechanistically, SOCS3 is recruited to a site in the cytokine receptors known as the SOCS3-interaction motif, and then binds JAK molecules to inhibit their kinase activity. The SOCS3-interaction motif is found in receptors of the gp130 cytokine family but mostly absent from other cytokine receptors, including γc. Thus, SOCS3 has been considered a selective suppressor of gp130 family cytokines, but not γc cytokines. Considering that γc signaling induces SOCS3 expression in T cells, here we revisited the role of SOCS3 on γc signaling. Using SOCS3 transgenic mice, we found that increased abundance of SOCS3 not only suppressed signaling of the gp130 family cytokine IL-6, but also signaling of the γc family cytokine IL-7. Consequently, SOCS3 transgenic mice were impaired in IL-7-dependent T cell development in the thymus and the homeostasis of mature T cells in peripheral tissues. Moreover, enforced SOCS3 expression interfered with the generation of Foxp3⁺ regulatory T cells that requires signaling by the γc family cytokine IL-2. Collectively, we report an underappreciated role for SOCS3 in suppressing γc cytokine signaling, effectively expanding its scope of target cytokines in T cell immunity.

SOCS1 blocks G1-S transition in hepatocellular carcinoma by reducing the stability of the CyclinD1/CDK4 complex in the nucleus

Inhibitors of the CDK family of proteins have been approved for the treatment of a variety of tumours; however, the development of new drugs administered in combination with CDK inhibitors is expected to improve the therapeutic effect. We identified the function of suppressor of cytokine signalling 1 (SOCS1) in hepatocellular carcinoma (HCC) cell models and the xenograft mouse model. When SOCS1 expression was artificially upregulated, HCC cell lines were arrested at the G1-S transition in the cell cycle. Interestingly, during this process, total CyclinD1 protein increased, but the effective proportion decreased. We found that the deficiency of CyclinD1 in the nucleus is probably due to the decrease in the stability of nuclear CyclinD1 caused by the ubiquitin-based degradation of P21, thus inhibiting the progression of the cell cycle to S phase. After P21 expression was increased, the levels of the component that inactivates CyclinD1 decreased as expected. It showed that P21 has a partial promoting effect on cancer. SOCS1 is a good indicator of prognosis, tumour size and long-term survival after resection. SOCS1 is expected to become a drug target in combined with CDK family inhibitors.

The evolution and function characterization of suppressor of cytokine signaling 1b (SOCS1b) in miiuy croaker

The suppressor of cytokine signaling (SOCS) was first described as inhibitors of cytokine signaling. The SOCS1, as a number of SOCS family, is an important negative regulator in the IFN signaling pathways in mammals. While data on functional characterization of SOCS1 in lower vertebrates are limited. In this study, we identified and characterized the full length SOCS1b gene of miiuy croaker (Miichthys miiuy). The sequence alignment analysis results showed that miiuy croaker SOCS1b (mmSOCS1b) have only a conserved SH2 domain that is similar to other vertebrates. To further study the functions of mmSOCS1b, we identified and determined its potential ability to perceive poly (I:C) stimulation. Stimulation experiments with poly (I:C) showed the significantly upregulated expression of mmSOCS1b in crucial immune-related tissues of spleen and kidney, indicating that mmSOCS1b might participate in the immune responses. Furthermore, the immunofluorescence assay indicated that mmSOCS1b present in the cytoplasmic of HeLa cells. In addition, mmSOCS1b could inhibit IFNα or IFNγ-induced ISRE reporter gene. In a word, we systematically and comprehensively analyzed the characterizations and functions of mmSOCS1b, which not only enriches the current knowledge of SOCS in IFN signaling regulation but also offer the basis for future research of fish SOCS family.

Porcine Reproductive and Respiratory Syndrome Virus Enhances Self-Replication via AP-1-Dependent Induction of SOCS1

Porcine reproductive and respiratory syndrome virus (PRRSV) has caused tremendous economic losses in the swine industry since its emergence in the late 1980s. PRRSV exploits various strategies to evade immune responses and establish chronic persistent infections. Suppressor of cytokine signaling (SOCS) 1, a member of the SOCS family, is a crucial intracellular negative regulator of innate immunity. In this study, it was shown that SOCS1 can be co-opted by PRRSV to evade host immune responses, facilitating viral replication. It was observed that PRRSV induced SOCS1 production in porcine alveolar macrophages, monkey-derived Marc-145 cells, and porcine-derived CRL2843-CD163 cells. SOCS1 inhibited the expression of IFN-β and IFN-stimulated genes, thereby markedly enhancing PRRSV replication. It was observed that the PRRSV N protein has the ability to upregulate SOCS1 production and that nuclear localization signal-2 (NLS-2) is essential for SOCS1 induction. Moreover, SOCS1 upregulation was dependent on p38/AP-1 and JNK/AP-1 signaling pathways rather than classical type I IFN signaling pathways. In summary, to our knowledge, the findings of this study uncovered the molecular mechanism that underlay SOCS1 induction during PRRSV infection, providing new insights into viral immune evasion and persistent infection.

Dissociating STAT4 and STAT5 Signaling Inhibitory Functions of SOCS3: Effects on CD8 T Cell Responses

Cytokines are critical for guiding the differentiation of T lymphocytes to perform specialized tasks in the immune response. Developing strategies to manipulate cytokine-signaling pathways holds promise to program T cell differentiation toward the most therapeutically useful direction. Suppressor of cytokine signaling (SOCS) proteins are attractive targets, as they effectively inhibit undesirable cytokine signaling. However, these proteins target multiple signaling pathways, some of which we may need to remain uninhibited. SOCS3 inhibits IL-12 signaling but also inhibits the IL-2–signaling pathway. In this study, we use computational protein design based on SOCS3 and JAK crystal structures to engineer a mutant SOCS3 with altered specificity. We generated a mutant SOCS3 designed to ablate interactions with JAK1 but maintain interactions with JAK2. We show that this mutant does indeed ablate JAK1 inhibition, although, unexpectedly, it still coimmunoprecipitates with JAK1 and does so to a greater extent than with JAK2. When expressed in CD8 T cells, mutant SOCS3 preserved inhibition of JAK2-dependent STAT4 phosphorylation following IL-12 treatment. However, inhibition of STAT phosphorylation was ablated following stimulation with JAK1-dependent cytokines IL-2, IFN-α, and IL-21. Wild-type SOCS3 inhibited CD8 T cell expansion in vivo and induced a memory precursor phenotype. In vivo T cell expansion was restored by expression of the mutant SOCS3, and this also reverted the phenotype toward effector T cell differentiation. These data show that SOCS proteins can be engineered to fine-tune their specificity, and this can exert important changes to T cell biology.

Jak-Stat Signaling Induced by Interleukin-6 Family Cytokines in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. It can be caused by chronic liver cell injury with resulting sustained inflammation, e.g., triggered by infections with hepatitis viruses B (HBV) and C (HCV). Death of hepatocytes leads to the activation of compensatory mechanisms, which can ultimately result in liver fibrosis and cirrhosis. Another common feature is the infiltration of the liver with inflammatory cells, which secrete cytokines and chemokines that act directly on the hepatocytes. Among several secreted proteins, members of the interleukin-6 (IL-6) family of cytokines have emerged as important regulatory proteins that might constitute an attractive target for therapeutic intervention. The IL-6-type cytokines activate multiple intracellular signaling pathways, and especially the Jak/STAT cascade has been shown to be crucial for HCC development. In this review, we give an overview about HCC pathogenesis with respect to IL-6-type cytokines and the Jak/STAT pathway. We highlight the role of mutations in genes encoding several proteins involved in the cytokine/Jak/STAT axis and summarize current knowledge about IL-6 family cytokines in this context. We further discuss possible anti-cytokine therapies for HCC patients in comparison to already established therapies.

Innate Immune Evasion of Alphaherpesvirus Tegument Proteins

Alphaherpesviruses are a large family of highly successful human and animal DNA viruses that can establish lifelong latent infection in neurons. All alphaherpesviruses have a protein-rich layer called the tegument that, connects the DNA-containing capsid to the envelope. Tegument proteins have a variety of functions, playing roles in viral entry, secondary envelopment, viral capsid nuclear transportation during infection, and immune evasion. Recently, many studies have made substantial breakthroughs in characterizing the innate immune evasion of tegument proteins. A wide range of antiviral tegument protein factors that control incoming infectious pathogens are induced by the type I interferon (IFN) signaling pathway and other innate immune responses. In this review, we discuss the immune evasion of tegument proteins with a focus on herpes simplex virus type I.

Upstream regulators of phosphoinositide 3-kinase and their role in diseases

Phosphoinositide 3-kinase (PI3K), a crucial signaling molecule, is regulated by various upstream regulators. Traditionally, receptor tyrosine kinases and G protein-coupled receptor are regarded as its principle upstream regulators; however, recent reports have indicated that spleen tyrosine kinase, β-arrestin2, Janus kinase, and RAS can also perform this role. Dysregulation of PI3K is common in the progression of various diseases, including, but not limited to, tumors, Alzheimer's disease, Parkinson's disease, rheumatoid arthritis, and acute myelogenous leukemia. The aim of this review is to provide a perspective on PI3K-related diseases examining both the classical and nonclassical upstream regulators of PI3K in detail.

Decoding inflammation, its causes, genomic responses, and emerging countermeasures

Inflammation is the mechanism of diseases caused by microbial, autoimmune, allergic, metabolic and physical insults that produce distinct types of inflammatory responses. This aetiologic view of inflammation informs its classification based on a cause‐dependent mechanism as well as a cause‐directed therapy and prevention. The genomic era ushered in a new understanding of inflammation by highlighting the cell's nucleus as the centre of the inflammatory response. Exogenous or endogenous inflammatory insults evoke genomic responses in immune and non‐immune cells. These genomic responses depend on transcription factors, which switch on and off a myriad of inflammatory genes through their regulatory networks. We discuss the transcriptional paradigm of inflammation based on denying transcription factors’ access to the nucleus. We present two approaches that control proinflammatory signalling to the nucleus. The first approach constitutes a novel intracellular protein therapy with bioengineered physiologic suppressors of cytokine signalling. The second approach entails control of proinflammatory transcriptional cascades by targeting nuclear transport with a cell‐penetrating peptide that inhibits the expression of 23 out of the 26 mediators of inflammation along with the nine genes required for metabolic responses. We compare these emerging anti‐inflammatory countermeasures to current therapies. The transcriptional paradigm of inflammation offers nucleocentric strategies for microbial, autoimmune, metabolic, physical and other types of inflammation afflicting millions of people worldwide.