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

IFN-τ Maintains Immune Tolerance by Promoting M2 Macrophage Polarization via Modulation of Bta-miR-30b-5p in Early Uterine Pregnancy in Dairy Cows

Pregnancy failure in the first trimester of cows significantly impacts the efficiency of the dairy industry. As a type I interferon exclusively to ruminants, IFN-τ plays a key role in maternal recognition and immune tolerance of fetuses. Macrophages are the most common immune cells within the ruminant endometrium. Nevertheless, deeply analyzing the mechanisms of IFN-τ regulating macrophage polarization still needs further study. In this study, a notable decline of bta-miR-30b-5p expression via the increase of SOCS1 was observed in uterine tissues of pregnant cows. We then confirmed that the 3'UTR of SOCS1 was to be directly targeted by bta-miR-30b-5p. After that, we demonstrated that this obviously promoted the bovine macrophages (BoMac) polarized to M2 through enhancing SOCS1 expression with the treatment of IFN-τ. Furthermore, we found that SOCS1 restrained the expression of the key proteins p65 and p-P65 in the NF-κB pathway. Causing, the wide range of cross-species activities of IFN-τ, therefore we established a pregnant mouse model for the future confirmation of the above mechanism. The results verified that IFN-τ significantly improved this mechanism and maintained normal pregnancy status in mice, but miR-30b-5p significantly reduced the M2 polarization by inhibiting SOCS1, which activated the NF-κB signaling pathway, and then leading to the failure of embryo implantation. All these results indicated that IFN-τ can regulate immune tolerance during pregnancy by promoting M2 macrophage polarization through inhibiting bta-miR-30b-5p targeting SOCS1 to deactivate the NF-κB signaling pathway.

Legius Syndrome mutations in the Ras-regulator SPRED1 abolish its membrane localization and potentially cause neurodegeneration

The SPRED family proteins act as negative regulators of the Ras-ERK pathway: the N-terminal EVH1 domain interacts with the Ras-GAP domain (GRD) of the NF1 protein, while the C-terminal Sprouty-related (SPR) domain promotes membrane localization of SPRED, thereby recruiting NF-1 to Ras. Loss-of-function mutations in the hSPRED1 cause Legius syndrome in an autosomal dominant manner. In this study, we investigated the effects of missense mutations in the SPR domain identified in patients with Legius syndrome. Among 18 mutations we examined, six (C368S, M369L, V408E, P415A, P415L and P422R) have defects in the palmitoylation of the SPRED1 protein, losing plasma membrane localization and forming cytoplasmic granular aggregates. To evaluate the in vivo effects of SPR mutations, knock-in (KI) mice with P415A and P415V substitutions or M417Afs*4, a C-terminal 28 amino acid deletion, were generated. All these KI mice exhibited cranial malformations, a characteristic feature of Legius syndrome. However, both P415A and P415V mutants formed granular aggregates, whereas M417Afs*4 showed a diffuse cytoplasmic distribution, and Spred1P415A and Spred1P415V mice, but not Spred1M417Afs∗4 mice, developed cerebellar ataxia and Purkinje cell loss with age. These data suggest that in addition to loss of palmitoylation, the C-terminal region is required for the granular aggregate formation and Purkinje cell loss. The autophagy inducer spermidine rescued the ataxia phenotypes and Purkinje cell loss in Spred1P415A mice. These results suggest that some, but not all, SPR mutations that lose lipid modification induce abnormal cytoplasmic aggregation, which could be a target for autophagic clearance, and potentially cause neurodegenerative diseases.

Unveiling the pathological functions of SOCS in colorectal cancer: Current concepts and future perspectives

Colorectal cancer (CRC) remains a significant global health challenge, marked by increasing incidence and mortality rates in recent years. The pathogenesis of CRC is complex, involving chronic inflammation of the intestinal mucosa, heightened immunoinflammatory responses, and resistance to apoptosis. The suppressor of cytokine signaling (SOCS) family, comprised of key negative regulators within cytokine signaling pathways, plays a crucial role in cell proliferation, growth, and metabolic regulation. Deficiencies in various SOCS proteins can trigger the activation of the Janus kinase (JAK) and signal transducers and activators of transcription (STAT) pathways, following the binding of cytokines and growth factors to their receptors. Mounting evidence indicates that SOCS proteins are integral to the development and progression of CRC, positioning them as promising targets for novel anticancer therapies. This review delves into the structure, function, and molecular mechanisms of SOCS family members, examining their roles in cell proliferation, apoptosis, migration, epithelial-mesenchymal transition (EMT), and immune modulation. Additionally, it explores their potential impact on the regulation of CRC immunotherapy, offering new insights and perspectives that may inform the development of innovative therapeutic strategies for CRC.

A metal-organic nanoframework for efficient colorectal cancer immunotherapy by the cGAS-STING pathway activation and immune checkpoint blockade

Immunotherapy has shown marked progress in promoting systemic anti-colorectal cancer (CRC) clinical effects. For further effectively sensitizing CRC to immunotherapy, we have engineered a pH-sensitive zeolitic imidazolate framework-8 (CS/NPs), capable of efficient cGAS-STING pathway activation and immune checkpoint blockade, by encapsulating the chemotherapeutic mitoxantrone (MTX) and immunomodulator thymus pentapeptide (TP5) and tailoring with tumor-targeting chondroitin sulfate (CS). In this nanoframework, CS endows CS/NPs with specific tumor-targeting activity and reduced systemic toxicity. Of note, the coordinated Zn2+ disrupts glycolytic processes and downregulates the expression of glucose transporter type 1 (GLUT1), thus depriving the cancer cells of their energy. Zn2+ further initiates the adenosine 5'-monophosphate activated protein kinase (AMPK) pathway, which leads to PD-L1 protein degradation and sensitizes CRC cells to immunotherapy. Moreover, the damaged double-stranded DNA during MTX treatment activates the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway, which works together with TP5 induced the proliferation and differentiation of T lymphocytes and dendritic cells to further enhance the anti-CRC immune response. Therefore, CS/NPs efficiently sensitize cells to chemotherapy and stimulate systemic antitumor immune responses both in vitro and in vivo, representing a promising strategy to increase the feasibility of CRC immunotherapy.

STAT1 as a potential therapeutic target to treat bladder cancer

BACKGROUND

Previous studies have reported that STAT1 (Signal Transducer and Activator of Transcription 1) is associated with multiple tumor progression. This study aimed to investigate the role and related mechanisms of STAT1 in bladder cancer.

METHODS

STAT1 expression in bladder cancer tissues and human bladder cancer cell lines was assessed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The bladder cancer cell line T24 was transfected with overexpressing lentivirus targeting STAT1. Cell proliferation, invasion, and apoptosis were measured by Cell Counting Kit-8, Transwell assays, and flow cytometric analysis. Furthermore, RNA-Seq was performed to identify the downstream signaling pathways. Finally, the signaling pathway-related molecules were determined by RT-qPCR and western blot assays.

RESULTS

The overexpression of STAT1 inhibited bladder cancer cell proliferation and invasion while enhancing apoptosis. Moreover, the overexpression of STAT1 in bladder cancer cells delayed tumor tumorigenesis in vitro. Mechanistically, RNA-Seq analysis revealed that the JAK-STAT signaling pathway was up-regulated, especially SOCS1 (suppressor of cytokine signaling 1) and SOCS3 (suppressor of cytokine signaling 3) in STAT1-sufficient cells.

CONCLUSIONS

These results indicate the potential of STAT1 as a therapeutic target in bladder cancer.

Oxidized low-density lipoproteins impair the pro-atherosclerotic effect of granulocyte-macrophage-colony-stimulating factor-producing T helper cells on macrophages

T cells contribute to the pathogenesis of atherosclerosis. However, the presence and function of granulocyte-macrophage-colony-stimulating factor (GM-CSF)-producing T helper (ThGM) cells in atherosclerosis development is unknown. This study aims to characterize the phenotype and function of ThGM cells in experimental atherosclerosis. Atherosclerosis was induced by feeding apolipoprotein E knockout (ApoE-/-) mice with a high-fat diet. Aortic ThGM cells were detected and sorted by flow cytometry. The effect of oxidized low-density lipoprotein (oxLDL) on ThGM cells and the impact of ThGM cells on macrophages were evaluated by flow cytometry, quantitative RT-PCR, oxLDL binding/uptake assay, immunoblotting and foam cell formation assay. We found that GM-CSF+IFN-γ- ThGM cells existed in atherosclerotic aortas. Live ThGM cells were enriched in aortic CD4+CCR6-CCR8-CXCR3-CCR10+ T cells. Aortic ThGM cells triggered the expression of interleukin-1β (IL-1β), tumour necrosis factor (TNF), interleukin-6 (IL-6) and C-C motif chemokine ligand 2 (CCL2) in macrophages. Besides, aortic ThGM cells expressed higher CD69 than other T cells and bound to oxLDL. oxLDL suppressed the cytokine expression in ThGM cells probably via inhibiting the signal transducer and activator of transcription 5 (STAT5) signalling. Furthermore, oxLDL alleviated the effect of ThGM cells on inducing macrophages to produce pro-inflammatory cytokines and generate foam cells. The nuclear receptor subfamily 4 group A (NR4A) members NR4A1 and NR4A2 were involved in the suppressive effect of oxLDL on ThGM cells. Collectively, oxLDL suppressed the supportive effect of ThGM cells on pro-atherosclerotic macrophages.

NR4a1/2 deletion promotes accumulation of TCF1+ stem-like precursors of exhausted CD8+ T cells in the tumor microenvironment

T cell exhaustion impairs tumor immunity and contributes to resistance against immune checkpoint inhibitors. The nuclear receptor subfamily 4 group A (NR4a) family of nuclear receptors plays a crucial role in driving T cell exhaustion. In this study, we observe that NR4a1 and NR4a2 deficiency in CD8+ tumor-infiltrating lymphocytes (TILs) results in potent tumor eradication and exhibits not only reduced exhaustion characteristics but also an increase in the precursors/progenitors of exhausted T (Pre-Tex) cell fraction. Serial transfers of NR4a1-/-NR4a2-/-CD8+ TILs into tumor-bearing mice result in the expansion of TCF1+ (Tcf7+) stem-like Pre-Tex cells, whereas wild-type TILs are depleted upon secondary transfer. NR4a1/2-deficient CD8+ T cells express higher levels of stemness/memory-related genes and illustrate potent mitochondrial oxidative phosphorylation. Collectively, these findings suggest that inhibiting NR4a in tumors represents a potent immuno-oncotherapy strategy by increasing stem-like Pre-Tex cells and reducing exhaustion of CD8+ T cells.

Inflammatory Skin Diseases: Focus on the Role of Suppressors of Cytokine Signaling (SOCS) Proteins

Inflammatory skin diseases include a series of disorders characterized by a strong activation of the innate and adaptive immune system in which proinflammatory cytokines play a fundamental role in supporting inflammation. Skin inflammation is a complex process influenced by various factors, including genetic and environmental factors, characterized by the dysfunction of both immune and non-immune cells. Psoriasis (PS) and atopic dermatitis (AD) are the most common chronic inflammatory conditions of the skin whose pathogeneses are very complex and multifactorial. Both diseases are characterized by an immunological dysfunction involving a predominance of Th1 and Th17 cells in PS and of Th2 cells in AD. Suppressor of cytokine signaling (SOCS) proteins are intracellular proteins that control inflammatory responses by regulating various signaling pathways activated by proinflammatory cytokines. SOCS signaling is involved in the regulation and progression of inflammatory responses in skin-resident and non-resident immune cells, and recent data suggest that these negative modulators are dysregulated in inflammatory skin diseases such as PS and AD. This review focuses on the current understanding about the role of SOCS proteins in modulating the activity of inflammatory mediators implicated in the pathogenesis of inflammatory skin diseases such as PS and AD.

Monkeypox Virus Crosstalk with HIV: An Integrated Skin Transcriptome and Machine Learning Study

The emergence of the monkeypox virus (MPXV) outbreak presents a formidable challenge to human health. Emerging evidence suggests that individuals with HIV have been disproportionately affected by MPXV, with adverse clinical outcomes and higher mortality rates. However, the shared molecular mechanisms underlying MPXV and HIV remain elusive. We identified differentially expressed genes (DEGs) from two public data sets, GSE219036 and GSE184320, and extracted common DEGs between MPXV and HIV. We further performed gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), protein-protein interactions (PPI), candidate drug assessment, and immune correlation of hub genes analysis. We validated the key biomarkers using multiple machine learning (ML) methods including random forest (RF), t-distributed stochastic neighbor embedding (tSNE), and uniform manifold approximation and projection (UMAP). A total of 59 common DEGs were identified between MPXV and HIV. Our functional analysis highlighted multiple pathways, including the ERK cascade, NF-κB signaling, and various immune responses, playing a collaborative role in the progression of both diseases. The PPI and gene co-expression networks were constructed, and five key genes with significant immune correlations were identified and validated by multiple ML models, including SPRED1, SPHK1, ATF3, AKT3, and AKT1S1. Our study emphasizes the common pathogenesis of HIV and MPXV and highlights the pivotal genes and shared pathways, providing new opportunities for evidence-based management strategies in HIV patients co-infected with MPXV.

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

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

SOCS3 deletion in effector T cells confers an anti-tumorigenic role of IL-6 to the pro-tumorigenic cytokine

Interleukin (IL)-6 is abundantly expressed in the tumor microenvironment and is associated with poor patient outcomes. Here, we demonstrate that the deletion of the suppressor of cytokine signaling 3 (SOCS3) in T cells potentiates anti-tumor immune responses by conferring the anti-tumorigenic function of IL-6 in mouse and human models. In Socs3-deficient CD8+ T cells, IL-6 upregulates the expression of type I interferon (IFN)-regulated genes and enhances the anti-tumor effector function of T cells, while also modifying mitochondrial fitness to increase mitochondrial membrane potential and reactive oxygen species (ROS) levels and to promote metabolic glycolysis in the energy state. Furthermore, Socs3 deficiency reduces regulatory T cells and increases T helper 1 (Th1) cells. SOCS3 knockdown in human chimeric antigen receptor T (CAR-T) cells exhibits a strong anti-tumor response in humanized mice. Thus, genetic disruption of SOCS3 offers an avenue to improve the therapeutic efficacy of adoptive T cell therapy.

CLEC16A-An Emerging Master Regulator of Autoimmunity and Neurodegeneration

CLEC16A is emerging as an important genetic risk factor for several autoimmune disorders and for Parkinson disease (PD), opening new avenues for translational research and therapeutic development. While the exact role of CLEC16A in health and disease is still being elucidated, the gene plays a critical role in the regulation of autophagy, mitophagy, endocytosis, intracellular trafficking, immune function, and in biological processes such as insulin secretion and others that are important to cellular homeostasis. As shown in both human and animal modeling studies, CLEC16A hypofunction predisposes to both autoinflammatory phenotype and neurodegeneration. While the two are clearly related, further functional studies are needed to fully understand the mechanisms involved for optimized therapeutic interventions. Based on recent data, mitophagy-inducing drugs may be warranted, and such therapy should be tested in clinical trials as these drugs would tackle the underlying pathogenic mechanism (s) and could treat or prevent symptoms of autoimmunity and neurodegeneration in individuals with CLEC16A risk variants. Accordingly, interventions directed at reversing the dysregulated mitophagy and the consequences of loss of function of CLEC16A without activating other detrimental cellular pathways could present an effective therapy. This review presents the emerging role of CLEC16A in health and disease and provides an update on the disease processes that are attributed to variants located in the CLEC16A gene, which are responsible for autoimmune disorders and neurodegeneration with emphasis on how this information is being translated into practical and effective applications in the clinic.

Role of the nuclear receptor subfamily 4a in mast cells in the development of irritable bowel syndrome

The activation of mast cells (MCs) and mediator release are closely related to the pathophysiology of irritable bowel syndrome (IBS). However, the exact underlying mechanisms are still not completely understood. The nuclear receptor subfamily 4a (Nr4a) is a family of orphan nuclear receptors implicated in regulating MC activation, degranulation, cytokine/chemokine synthesis and release. Acute and chronic stress trigger hypothalamic–pituitaryadrenal axis (HPA) activation to induce the release of corticotropin-releasing hormone (CRH), resulting in MC activation and induction of the Nr4a family. Our newest data showed that Nr4a members were specially over-expressed in colonic MCs of the chronic water-avoidance stress (WAS)-induced visceral hyperalgesia mice, suggesting that Nr4a members might be involved in the pathophysiology of visceral hypersensitivity. In this review, we highlight the present knowledge on roles of Nr4a members in the activation of MCs and the pathophysiology of IBS, and discuss signaling pathways that modulate the activation of Nr4a family members. We propose that a better understanding of Nr4a members and their modulators may facilitate the development of more selective and effective therapies to treat IBS patients.