Inflammatory factor-mediated miR-155/SOCS1 signaling axis leads to Treg impairment in systemic lupus erythematosus.

BACKGROUND: Systemic lupus erythematosus (SLE) is an autoimmune disorder associated with the decrease and functional impairment of regulatory T cells (Tregs). In the current study, we explored the interplay of miR-155 and suppressor of cytokine signaling 1 (SOCS1) in regulating Treg function and stability in SLE. METHODS: Clinical samples from healthy subjects and SLE patients were collected, and a mouse model of SLE was established to profile the expression pattern of miR-155 and SCOS1 in Tregs. Tregs isolated from mouse spleen were stimulated by inflammatory cytokines to confirm involvement of miR-155/SOCS1 axis in dictating Treg stability and function. We also administrated synthetic miR-155 inhibitor in SLE animal model to evaluate the potential effect on rescuing Treg function and alleviating SLE progression. RESULTS: Tregs from SLE patients and SLE-induced mice exhibited a downregulation of SOCS1 and an upregulation of miR-155. In Tregs stimulated by inflammatory cytokines, Nuclear factor kappa B (NF-κB) signaling activation was required for the change of SOCS1 and miR-155 expression. miR-155 served as a negative regulator to dampen SOCS1 expression in inflammation-stimulated Tregs. The transfection of miR-155 mimic impaired the suppressive function and differentiation of Tregs through targeting SOCS1. In contrast, miR-155 inhibition improved Treg function under inflammatory stimulation and alleviated SLE conditions in the mouse model. CONCLUSION: Inflammation-induced miR-155 impairs Treg stability and function in SLE through decreasing SOCS1 expression. Targeting miR-155 might be developed as an intervention to mitigate SLE conditions.

GDF15 attenuates sepsis-induced myocardial dysfunction by inhibiting cardiomyocytes ferroptosis via the SOCS1/GPX4 signaling pathway.

Sepsis is a systemic inflammatory response syndrome triggered by infection, presenting with symptoms such as fever, increased heart rate, and low blood pressure. In severe cases, it can lead to multiple organ dysfunction, posing a life-threatening risk. Sepsis-induced cardiomyopathy (SIC) is a critical factor in the poor prognosis of septic patients, leading to myocardial dysfunction characterized by cell death, inflammation, and diminished cardiac function. Ferroptosis, an iron-dependent form of programmed cell death, is a key mechanism causing cardiomyocyte damage in SIC. Growth differentiation factor 15 (GDF15), a member of the TGF-ß superfamily, is associated with various cardiovascular diseases and can inhibit oxidative stress, reduce reactive oxygen species (ROS), and suppress ferroptosis. Elevated serum GDF15 levels in sepsis are correlated with organ injuries, suggesting its potential as a therapeutic target. However, its role and mechanisms in SIC remain unclear. Glutathione peroxidase 4 (GPX4), the only enzyme capable of reducing lipid peroxides within cells, protects cells by reducing lipid peroxidation levels and inhibiting ferroptosis. Investigating the regulatory factors of GPX4 may provide a theoretical basis for SIC treatment. In this study, a mouse SIC model revealed that elevated GDF15 exerts a protective effect. Antagonizing GDF15 exacerbates myocardial damage. Through transcriptomic analysis and other methods, we confirmed that GDF15 inhibits the expression of SOCS1 by activating the ALK5-SMAD2/3 pathway, thereby activates the JAK2/STAT3 pathway, promotes the transcription of GPX4, inhibits ferroptosis in cardiomyocytes, and plays a myocardial protective role in SIC.

Corneal application of SOCS1/3 peptides for the treatment of eye diseases mediated by inflammation and oxidative stress.

Several blinding diseases affecting the retina and optic nerve are exacerbated by or caused by dysregulated inflammation and oxidative stress. These diseases include uveitis, age related macular degeneration, diabetic retinopathy and glaucoma. Consequently, despite their divergent symptoms, treatments that reduce oxidative stress and suppress inflammation may be therapeutic. The production of inflammatory cytokines and their activities are regulated by a class of proteins termed Suppressors of Cytokine Signaling (SOCS). SOCS1 and SOCS3 are known to dampen signaling via pathways employing Janus kinases and signal transducer and activator of transcription proteins (JAK/STAT), Toll-like Receptors (TLR), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), mitogen activated kinase (MAPK) and NLR family pyrin domain containing 3 (NLRP3). We have developed cell-penetrating peptides from the kinase inhibitory region of the SOCS1 and SOCS3 (denoted as R9-SOCS1-KIR and R9-SOCS3-KIR) and tested them in retinal pigment epithelium (RPE) cells and in macrophage cell lines. SOCS-KIR peptides exhibited anti-inflammatory, anti-oxidant and anti-angiogenic properties. In cell culture, both Th1 and Th17 cells were suppressed together with the inhibition of other inflammatory markers. We also observed a decrease in oxidants and a simultaneous rise in neuroprotective and anti-oxidant effectors. In addition, treatment prevented the loss of gap junction proteins and the ensuing drop in transepithelial electrical resistance in RPE cells. When tested in mouse models by eye drop instillation, they showed protection against autoimmune uveitis, as a prophylactic as well as a therapeutic. Mice with endotoxin-induced uveitis were protected by eye drop administration as well. R9-SOCS3-KIR was particularly effective against the pathways acting through STAT3, e.g. IL-6 and VEGF-A mediated responses that lead to macular degeneration. Eye drop administration of R9-SOCS3-KIR stimulated production of antioxidant effectors and reduced clinical symptoms in mouse model of oxidative stress that replicates the RPE injury occurring in AMD. Because these peptides suppress multiple pathogenic stimuli and because they can be delivered topically to the cornea, they are attractive candidates for therapeutics for uveitis, macular degeneration, diabetic retinopathy and glaucoma.

KLF4-induced upregulation of SOCS1 ameliorates myocardial ischemia/reperfusion injury by attenuating AC16 cardiomyocyte damage and enhancing M2 macrophage polarization.

Reperfusion strategies, the standard therapy for acute myocardial infarction (AMI), may result in ischemia/reperfusion (I/R) damage. Suppressor of cytokine signaling1 (SOCS1) exerts a cardioprotective function in myocardial I/R damage. Here, we investigated epigenetic modulators that deregulate SOCS1 in cardiomyocytes under hypoxia/reoxygenation (H/R) conditions. Human AC16 cardiomyocytes were exposed to H/R conditions to generate a cell model of myocardial I/R damage. Expression of mRNA and protein was detected by quantitative PCR and western blot analysis, respectively. Cell migratory and invasive abilities were evaluated by transwell assay. Cell apoptosis and M2 macrophage polarization were assessed by flow cytometry. TNF-α, IL-1ß, and IL-6 levels were examined by ELISA. The interaction of KLF4 with SOCS1 was verified by chromatin immunoprecipitation and luciferase assays. SOCS1 and transcription factor KLF4 protein levels were underexpressed by 75% and 57%, respectively, in H/R-exposed AC16 cardiomyocytes versus control cells. Under H/R conditions, forced SOCS1 expression (2.7 times) induced cell migration (2.2 times) and invasion (1.9 times) and hindered cell apoptosis (by 45%) of AC16 cardiomyocytes as well as enhanced M2 macrophage polarization (4.6 times). Mechanistically, KLF4 upregulation promoted SOCS1 transcription (2.6 times) and expression (2.6 times) by binding to the SOCS1 promoter. Decrease of SOCS1 (by 51%) reversed the effects of KLF4 upregulation on cardiomyocyte migration, invasion and apoptosis, and M2 macrophage polarization under H/R conditions. Additionally, SOCS1 and KLF4 were underexpressed by 56% and 63%, respectively, in AMI serum. Our study indicates that KLF4-induced upregulation of SOCS1 can attenuate H/R-triggered apoptosis of AC16 cardiomyocytes and enhance M2 macrophage polarization.

The expression of SOCS1 is regulated by promoter DNA methylation and is associated with mitochondria-mediated apoptosis of T-2 induced chondrocytes.

At present, the function of SOCS1 in Kashin-Beck disease (KBD) has not been reported. This study aims to explore the expression and mechanism of SOCS1 in KBD, and provide theoretical basis for the prevention and treatment of KBD. The expression of SOCS1 were measured by qRT-PCR and Western blot. ELISA was used to detect the content of SOCS1 in serum and synovial fluid. CCK-8 kits were selected to measure the cell viability. Methylation Specific PCR (MSP) assay is used to detect the methylation level of SOCS1 in chondrocytes. Flow cytometry was used to analyze the apoptosis rate of chondrocytes in different groups. The expression of apoptosis related proteins (caspase-3 and caspase-9) and Cytochrome c were detected using Western blot. The mitochondrial ROS, ATP and the activity of mitochondrial respiratory chain complexes were detected using commercial kits. The results showed that the expression of SOCS1 significantly increases in KBD patients and T-2 induced chondrocytes. Further research has found that the methylation levels of SOCS1 were significantly reduced in KBD patients and T-2 induced chondrocytes. Functional studies have found that SOCS1 silencing inhibited chondrocyte apoptosis and mitochondrial dysfunction. More importantly, SOCS1 regulated mitochondrial mediated chondrocyte apoptosis through the IGF-1/IGF-1R/FAK/Drp1 pathway. In conclusion, SOCS1 expression is increased and methylation levels are decreased in KBD, and is involved in regulating mitochondrial mediated apoptosis in T-2 induced chondrocytes through IGF-1/IGF-1R/FAK/Drp1 signaling. This study provides new theoretical basis for the treatment and prevention of KBD in clinical practice.

Suppressor of Cytokine Signaling Proteins 3 and 5 Potentially Delineate Polarization of Th cells in Chronic Rhinosinusitis.

Background: Chronic rhinosinusitis (CRS) is an inflammatory condition classified into chronic rhinosinusitis with nasal polyps (CRSwNP) and chronic rhinosinusitis without nasal polyps (CRSsNP). Th cells manage inflammatory cells in CRS. Suppressor of Cytokine Signaling (SOCS) proteins regulate Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway in Th cells by polarizing toward Th1, Th2, and Th17 cells. This study evaluated the levels of SOCS1,3,5 in CRS patients to find associations with Th cells. Methods: In this cross-sectional study, 20 CRSwNP patients, 12 CRSsNP patients, and 12 controls participated. The infiltration of CD4+ T cells was determined using immunohistochemistry. The expression of specific transcription factors and SOCS proteins was assessed using real-time PCR. Cytokine levels were evaluated using ELISA. SOCS protein levels were investigated using western blot analysis. Results: The expression of SOCS3 increased in the CRSwNP group compared to CRSsNP and control groups (p <0.001). SOCS3 protein levels increased in the CRSwNP group compared to CRSsNP (p <0.05) and control (p <0.001) groups. Although there was a significant difference in SOCS5 expression between CRSsNP and control groups, SOCS5 protein levels were significantly different between CRSsNP and control (p <0.001) and CRSwNP (p <0.05) groups. Conclusions: Targeted therapies may be suggested for CRS by modulating SOCS3 and SOCS5 proteins that are responsible for polarization of Th cells toward Th2 or Th1 cells, respectively. JAK-STAT pathway targeting, which encompasses numerous cells, can be limited to SOCS proteins to more effectively orchestrate Th cell differentiation.

SOCS1 is a critical checkpoint in immune homeostasis, inflammation and tumor immunity.

The Suppressor of Cytokine Signaling (SOCS) family proteins are important negative regulators of cytokine signaling. SOCS1 is the prototypical member of the SOCS family and functions in a classic negative-feedback loop to inhibit signaling in response to interferon, interleukin-12 and interleukin-2 family cytokines. These cytokines have a critical role in orchestrating our immune defence against viral pathogens and cancer. The ability of SOCS1 to limit cytokine signaling positions it as an important immune checkpoint, as evidenced by the detection of detrimental SOCS1 variants in patients with cytokine-driven inflammatory and autoimmune disease. SOCS1 has also emerged as a key checkpoint that restricts anti-tumor immunity, playing both a tumor intrinsic role and impacting the ability of various immune cells to mount an effective anti-tumor response. In this review, we describe the mechanism of SOCS1 action, focusing on the role of SOCS1 in autoimmunity and cancer, and discuss the potential for new SOCS1-directed cancer therapies that could be used to enhance adoptive immunotherapy and immune checkpoint blockade.

SOCS1 and SOCS3 as key checkpoint molecules in the immune responses associated to skin inflammation and malignant transformation.

SOCS are a family of negative inhibitors of the molecular cascades induced by cytokines, growth factors and hormones. At molecular level, SOCS proteins inhibit the kinase activity of specific sets of receptor-associated Janus Activated Kinases (JAKs), thereby suppressing the propagation of intracellular signals. Of the eight known members, SOCS1 and SOCS3 inhibit activity of JAKs mainly induced by cytokines and can play key roles in regulation of inflammatory and immune responses. SOCS1 and SOCS3 are the most well-characterized SOCS members in skin inflammatory diseases, where their inhibitory activity on cytokine activated JAKs and consequent anti-inflammatory action has been widely investigated in epidermal keratinocytes. Structurally, SOCS1 and SOCS3 share the presence of a N-terminal domain containing a kinase inhibitory region (KIR) motif able to act as a pseudo-substrate for JAK and to inhibit its activity. During the last decades, the design and employment of SOCS1 and SOCS3-derived peptides mimicking KIR domains in experimental models of dermatoses definitively established a strong anti-inflammatory and ameliorative impact of JAK inhibition on skin inflammatory responses. Herein, we discuss the importance of the findings collected in the past on SOCS1 and SOCS3 function in the inflammatory responses associated to skin immune-mediated diseases and malignancies, for the development of the JAK inhibitor drugs. Among them, different JAK inhibitors have been introduced in the clinical practice for treatment of atopic dermatitis and psoriasis, and others are being investigated for skin diseases like alopecia areata and vitiligo.

[Correlations Between the Expression of MicroRNA-155 and Suppressor of Cytokine Signaling 1 in Colonic Mucosal Tissue and Disease Severity in Patients With Ulcerative Colitis].

Objective To explore the relationship between the expression levels of microRNA-155 (miR-155) and suppressor of cytokine signaling 1 (SOCS1) in the colonic mucosal tissue of patients with ulcerative colitis (UC) and the severity of the disease.Methods A total of 130 UC patients admitted to the Second Affiliated Hospital of Hebei North University from September 2021 to June 2023 were selected.According to the modified Mayo score system,the patients were assigned into an active stage group (n=85) and a remission stage group (n=45).According to the modified Truelove and Witts classification criteria,the UC patients at the active stage were assigned into a mild group (n=35),a moderate group (n=30),and a severe group (n=20).A total of 90 healthy individuals who underwent colonoscopy for physical examination or those who had normal colonoscopy results after single polypectomy and excluded other diseases were selected as the control group.The colonic mucosal tissues of UC patients with obvious lesions and the colonic mucosal tissue 20 cm away from the anus of the control group were collected.The levels of miR-155 and SOCS1 mRNA in tissues were determined by fluorescence quantitative PCR,and the expression of SOCS1 protein in tissues was determined by immunohistochemistry.The correlations of the levels of miR-155 and SOCS1 mRNA in the colonic mucosal tissue with the modified Mayo score of UC patients were analyzed.The values of the levels of miR-155 and SOCS1 mRNA in predicting the occurrence of severe illness in the UC patients at the active stage were evaluated.Results Compared with the control group and the remission stage group,the active stage group showed up-regulated expression level of miR-155,down-regulated level of SOCS1 mRNA,and decreased positive rate of SOCS1 protein in the colonic mucosal tissue (all P<0.001).The expression level of miR-155 and modified Mayo score in colonic mucosal tissues of UC patients at the active stage increased,while the mRNA level of SOCS1 was down-regulated as the disease evolved from being mild to severe (all P<0.001).The modified Mayo score was positively correlated with the miR-155 level and negative correlated with the mRNA level of SOCS1 in colonic mucosal tissues of UC patients (all P<0.001).The high miR-155 level (OR=2.762,95%CI=1.284-5.944,P=0.009),low mRNA level of SOCS1 (OR=2.617,95%CI=1.302-5.258,P=0.007),and modified Mayo score≥12 points (OR=3.232,95%CI=1.450-7.204,P=0.004) were all risk factors for severe disease in the UC patients at the active stage.The area under curve of miR-155 combined with SOCS1 mRNA in predicting severe illness in the UC patients at the active stage was 0.920.Conclusions The expression levels of miR-155 and SOCS1 mRNA were correlated with the disease severity in the UC patients at the active stage.The combination of the two indicators demonstrates good performance in predicting the occurrence of severe illness in UC patients at the active stage.

Tetrastigma hemsleyanum polysaccharide ameliorated ulcerative colitis by remodeling intestinal mucosal barrier function via regulating the SOCS1/JAK2/STAT3 pathway.

Ulcerative colitis (UC) is characterized by a chronic and protracted course and often leads to a poor prognosis. Patients with this condition often experience postoperative complications, further complicating the management of their condition. Tetrastigma hemsleyanum polysaccharide (THP) has demonstrated considerable potential as a treatment for inflammatory bowel disease. However, its underlying mechanism in the treatment of UC remains unclear. This study systematically and comprehensively investigated the effects of THP on dextran sulfate-induced UC mice and illustrated its specific mechanism of action. The colon and spleen in UC mice were restored after THP treatment. The levels of key markers, such as secretory immunoglobulin A, ß-defensin, and mucin-2 were increased, collagen deposition and epithelial cell apoptosis were decreased. Notably, THP administration led to increased levels of Ki67 and tight junction proteins in colon tissue and reduced colon tissue permeability. THP contributed to the restored balance of intestinal flora. Furthermore, THP downregulated the expressions of the proinflammatory cytokines interleukin (IL)-6, tumor necrosis factor (TNF)-α, and IL-17 and promoted those of the regulatory factors forkhead box protein P3. It also exerted anti-inflammatory effects by promoting suppressor of cytokine signaling (SOCS1) expression and inhibiting the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway. Our results demonstrated that THP had an efficacy comparable to that of JAK inhibitor in treating UC. In addition, THP might play a role in UC therapy through modulation of the SOCS1/JAK2/STAT3 signaling pathway and remodeling of the intestinal mucosal barrier.

Unmasking early colorectal cancer clues: in silico and in vitro investigation of downregulated IGF2, SOCS1, MLH1, and CACNA1G in SSA polyps.

BACKGROUND AND AIM: Colorectal cancer (CRC) originates from pre-existing polyps in the colon. The development of different subtypes of CRC is influenced by various genetic and epigenetic characteristics. CpG island methylator phenotype (CIMP) is found in about 15-20% of sporadic CRCs and is associated with hypermethylation of certain gene promoters. This study aims to find prognostic genes and compare their expression and methylation status as potential biomarkers in patients with serrated sessile adenomas/polyps (SSAP) and CRC, in order to evaluate which, one is a better predictor of disease. METHOD: This study employed a multi-phase approach to investigate genes associated with CRC and SSAP. Initially, two gene expression datasets were analyzed using R and Limma package to identify differentially expressed genes (DEGs). Venn diagram analysis further refined the selection, revealing four genes from the Weissenberg panel with significant changes. These genes, underwent thorough in silico evaluations. Once confirmed, they proceeded to wet lab experimentation, focusing on expression and methylation status. This comprehensive methodology ensured a robust examination of the genes involved in CRC and SSAP. RESULT: This study identified cancer-specific genes, with 8,351 and 1,769 genes specifically down-regulated in SSAP and CRC tissues, respectively. The down-regulated genes were associated with cell adhesion, negative regulation of cell proliferation, and drug response. Four highly downregulated genes in the Weissenberg panel, including CACNA1G, IGF2, MLH1, and SOCS1. In vitro analysis showed that they are hypermethylated in both SSAP and CRC samples while their expressions decreased only in CRC samples. CONCLUSION: This suggests that the decrease in gene expression could help determine whether a polyp will become cancerous. Using both methylation status and gene expression status of genes in the Weissenberg panel in prognostic tests may lead to better prognoses for patients.

One gene to rule them all - clinical perspectives of a potent suppressor of cytokine signaling - SOCS1.

The discovery of Suppressor of Cytokine Signaling 1 (SOCS1) in 1997 marked a significant milestone in understanding the regulation of Janus kinase/Signal transducer and activator of transcription (JAK/STAT) signaling pathways. Subsequent research deciphered its cellular functions, and recent insights into SOCS1 deficiencies in humans underscored its critical role in immune regulation. In humans, SOCS-haploinsufficiency (SOCS1-HI) presents a diverse clinical spectrum, encompassing autoimmune diseases, infection susceptibility, and cancer. Variability in disease manifestation, even within families sharing the same genetic variant, raises questions about clinical penetrance and the need for individualized treatments. Current therapeutic strategies include JAK inhibition, with promising results in controlling inflammation in SOCS1-HI patients. Hematopoietic stem cell transplantation and gene therapy emerge as promising avenues for curative treatments. The evolving landscape of SOCS1 research, emphasizes the need for a nuanced understanding of genetic variants and their functional consequences.

The Role of JAK-STAT-SOCS1 Axis in Tumorigenesis, Malignant Progression and Lymphatic Metastasis of Penile Cancer.

Background: To uncover the potential significance of JAK-STAT-SOCS1 axis in penile cancer, our study was the pioneer in exploring the altered expression processes of JAK-STAT-SOCS1 axis in tumorigenesis, malignant progression and lymphatic metastasis of penile cancer. Methods: In current study, the comprehensive analysis of JAK-STAT-SOCS1 axis in penile cancer was analyzed via multiple analysis approaches based on GSE196978 data, single-cell data (6 cancer samples) and bulk RNA data (7 cancer samples and 7 metastasis lymph nodes). Results: Our study observed an altered molecular expression of JAK-STAT-SOCS1 axis during three different stages of penile cancer, from tumorigenesis to malignant progression to lymphatic metastasis. STAT4 was an important dominant molecule in penile cancer, which mediated the immunosuppressive tumor microenvironment by driving the apoptosis of cytotoxic T cell and was also a valuable biomarker of immune checkpoint inhibitor treatment response. Conclusions: Our findings revealed that the complexity of JAK-STAT-SOCS1 axis and the predominant role of STAT4 in penile cancer, which can mediate tumorigenesis, malignant progression, and lymphatic metastasis. This insight provided valuable information for developing precise treatment strategies for patients with penile cancer.

MaiJiTong granule attenuates atherosclerosis by reducing ferroptosis via activating STAT6-mediated inhibition of DMT1 and SOCS1/p53 pathways in LDLR-/- mice.

BACKGROUND AND PURPOSE: Atherosclerosis is the primary pathological basis of cardiovascular disease. Ferroptosis is a regulated form of cell death, a process of lipid peroxidation driven by iron, which can initiate and promote atherosclerosis. STAT6 is a signal transducer that shows a potential role in regulating ferroptosis, but, the exact role in ferroptosis during atherogenesis remains unclear. The Traditional Chinese Medicine Maijitong granule (MJT) is used for treating cardiovascular disease and shows a potential inhibitory effect on ferroptosis. However, the antiatherogenic effect and the underlying mechanism remain unclear. In this study, we determined the role of STAT6 in ferroptosis during atherogenesis, investigated the antiatherogenic effect of MJT, and determined whether its antiatherogenic effect was dependent on the inhibition of ferroptosis. METHODS: 8-week-old male LDLR-/- mice were fed a high-fat diet (HFD) at 1st and 10th week, respectively, to assess the preventive and therapeutic effects of MJT on atherosclerosis and ferroptosis. Simultaneously, the anti-ferroptotic effects and mechanism of MJT were determined by evaluating the expression of genes responsible for lipid peroxidation and iron metabolism. Subsequently, we reanalyzed microarray data in the GSE28117 obtained from cells after STAT6 knockdown or overexpression and analyzed the correlation between STAT6 and ferroptosis. Finally, the STAT6-/- mice were fed HFD and injected with AAV-PCSK9 to validate the role of STAT6 in ferroptosis during atherogenesis and revealed the antiatherogenic and anti-ferroptotic effect of MJT. RESULTS: MJT attenuated atherosclerosis by reducing plaque lesion area and enhancing plaque stability in both preventive and therapeutic groups. MJT reduced inflammation via suppressing inflammatory cytokines and inhibited foam cell formation by lowering the LDL level and promoting ABCA1/G1-mediated lipid efflux. MJT ameliorated the ferroptosis by reducing lipid peroxidation and iron dysregulation during atherogenesis. Mechanistically, STAT6 negatively regulated ferroptosis by transcriptionally suppressing SOCS1/p53 and DMT1 pathways. MJT suppressed the DMT1 and SOCS1/p53 via stimulating STAT6 phosphorylation. In addition, STAT6 knockout exacerbated atherosclerosis and ferroptosis, which abolished the antiatherogenic and anti-ferroptotic effects of MJT. CONCLUSION: STAT6 acts as a negative regulator of ferroptosis and atherosclerosis via transcriptionally suppressing DMT1 and SOCS1 expression and MJT attenuates atherosclerosis and ferroptosis by activating the STAT6-mediated inhibition of DMT1 and SOCS1/p53 pathways, which indicated that STAT6 acts a novel promising therapeutic target to ameliorate atherosclerosis by inhibiting ferroptosis and MJT can serve as a new therapy for atherosclerosis treatment.

IL-13 facilitates ferroptotic death in asthmatic epithelial cells via SOCS1-mediated ubiquitinated degradation of SLC7A11.

Th2-high asthma is characterized by elevated levels of type 2 cytokines, such as interleukin 13 (IL-13), and its prevalence has been increasing worldwide. Ferroptosis, a recently discovered type of programmed cell death, is involved in the pathological process of Th2-high asthma; however, the underlying mechanisms remain incompletely understood. In this study, we demonstrated that the serum level of malondialdehyde (MDA), an index of lipid peroxidation, positively correlated with IL-13 level and negatively correlated with the predicted forced expiratory volume in 1 s (FEV1%) in asthmatics. Furthermore, we showed that IL-13 facilitates ferroptosis by upregulating of suppressor of cytokine signaling 1 (SOCS1) through analyzing immortalized airway epithelial cells, human airway organoids, and the ovalbumin (OVA)-challenged asthma model. We identified that signal transducer and activator of transcription 6 (STAT6) promotes the transcription of SOCS1 upon IL-13 stimulation. Moreover, SOCS1, an E3 ubiquitin ligase, was found to bind to solute carrier family 7 member 11 (SLC7A11) and catalyze its ubiquitinated degradation, thereby promoting ferroptosis in airway epithelial cells. Last, we found that inhibiting SOCS1 can decrease ferroptosis in airway epithelial cells and alleviate airway hyperresponsiveness (AHR) in OVA-challenged wide-type mice, while SOCS1 overexpression exacerbated the above in OVA-challenged IL-13-knockout mice. Our findings reveal that the IL-13/STAT6/SOCS1/SLC7A11 pathway is a novel molecular mechanism for ferroptosis in Th2-high asthma, confirming that targeting ferroptosis in airway epithelial cells is a potential therapeutic strategy for Th2-high asthma.

Kaempferol Ameliorated Alcoholic Hepatitis through Improving Intestinal Barrier Function by Targeting miRNA-155 Signaling.

INTRODUCTION: The aim of this study was to investigate the effect and mechanism of kaempferol on alcoholic steatohepatitis. METHODS: C57BL/6 N mice were utilized to establish Binge-on-Chronic alcohol exposure mice model. Kaempferol was given as the interventional drug to chronic alcohol-fed mice for 6 weeks to assess its effects. In vitro, intestinal epithelial Caco-2 cells were stimulated by alcohol, and miRNA-155 mimics were used to further study the effect of kaempferol to miRNA-155 signaling in intestinal epithelial cells. HE staining and oil red O staining were used to observe the liver and intestinal tissue damage in each group of mice, and ALT, AST, IL-1ß, and TNF-α were detected by kits; lipopolysaccharide (LPS) expression was detected by ELISA kit, and the expression of IL-1ß and TNF-α was assessed by qRT-PCR; Western blot was utilized to assess the excessive inflammatory response of liver and colon tissue and the related signaling pathway activation. RESULTS: Kaempferol treatment significantly improved pathological changes such as steatosis and vacuolated lesions in liver tissue of the alcohol diet model group, and reduced serum ALT and AST enzyme activities and liver tissue interleukin-1ß and tumor necrosis factor-α mRNA expression levels. Kaempferol significantly reduced the expression of miRNA-155 in the intestinal tissue of alcohol-fed mice, significantly increased their cytokine suppressor signaling 1 (SOCS1) protein expression, inhibited the activation of nuclear factor kappa-B and significantly increased the production of the intestinal tight junction proteins occludin and zonula occludens-1. More importantly, kaempferol significantly reduced serum LPS levels in alcoholic steatohepatitis mice. In vitro experiments showed that compared with the control group, kaempferol significantly inhibited the expression level of miRNA-155 in Caco-2 cells under ethanol exposure, decreased the activation of nuclear factor kappa-B, led to an increase in the expression of SOCS1 protein, and increased the production level of occludin protein in Caco-2 cells under the effect of alcohol. In contrast, overexpression of miRNA-155 significantly decreased occludin and SOCS1 protein production and increased nuclear factor kappa-B activation levels in Caco-2 cells, and the administration of kaempferol significantly inhibited this effect. CONCLUSION: Kaempferol improved the stability of gut barrier function to ameliorate hepatic injury induced by alcohol intake through enhancing occludin protein expression, by targeting miR-155 to inhibit the excessive inflammatory response in the intestine.

DDX4 enhances antiviral activity of type I interferon by disrupting interaction of USP7/SOCS1 and promoting degradation of SOCS1.

DEAD-box helicase (DDX) family members play differential roles in regulating innate antiviral immune response. However, the physiological roles played by DDX4 in antiviral innate immunity remain unclear. In this study, we unveiled that DDX4 acts as a positive regulatory molecule of Type-I interferon (IFN-I)-mediated antiviral activity. Our findings demonstrate that IFN-I upregulates DDX4 protein levels, and subsequently, overexpression of DDX4 enhances the IFN-I-mediated signaling pathway. This creates a positive feedback loop that amplifies the antiviral response. DDX4 was found to bind with deubiquitinase ubiquitin-specific protease 7 (USP7), leading to the disruption of the interaction between USP7 and suppressor of cytokine signaling 1 (SOCS1) and the subsequent degradation of SOCS1. This process enhances the antiviral function of IFN-I. Our findings provide new insights into the regulatory role of DDX4 in the IFN-I response.IMPORTANCEDDX4, identified as a putative RNA helicase that modulates RNA secondary structure through RNA binding, is primarily acknowledged for its role in regulating mRNA translation within the germline. Nevertheless, the extent of DDX4's involvement in the antiviral innate immune response remains largely unexplored. This study presents evidence of a previously unrecognized positive feedback loop between DDX4 and the antiviral response, suggesting that disruption of this loop may serve as a novel mechanism for viral evasion. Furthermore, our findings elucidate a positive regulatory mechanism by which the DDX4/USP7/SOCS1 axis mediates the antiviral activity of Type-I interferon, which provides new insight into strategies for improving the efficacy of IFN-based antiviral therapy.

SOCS1 expression in cancer cells: potential roles in promoting antitumor immunity.

Suppressor of cytokine signaling 1 (SOCS1) is a potent regulator immune cell responses and a proven tumor suppressor. Inhibition of SOCS1 in T cells can boost antitumor immunity, whereas its loss in tumor cells increases tumor aggressivity. Investigations into the tumor suppression mechanisms so far focused on tumor cell-intrinsic functions of SOCS1. However, it is possible that SOCS1 expression in tumor cells also regulate antitumor immune responses in a cell-extrinsic manner via direct and indirect mechanisms. Here, we discuss the evidence supporting the latter, and its implications for antitumor immunity.

LncRNA-HOXC-AS2 regulates tumor-associated macrophage polarization through the STAT1/SOCS1 and STAT1/CIITA pathways to promote the progression of non-small cell lung cancer.

Tumor-associated macrophages (TAMs) mainly exhibit the characteristics of M2-type macrophages, and the regulation of TAM polarization is a new target for cancer therapy, among which lncRNAs are key regulatory molecules. This study aimed to explore the effects of lncRNA-HOXC-AS2 on non-small cell lung cancer (NSCLC) by regulating TAM polarization. THP-1 cells were used to differentiate into macrophages, and TAMs were obtained by coculture with A549 cells. The M1/M2 cell phenotype and HOXC-AS2 expression were detected, and A549-derived exosomes (A549-exo) were used to elucidate the effects of A549 on macrophage polarization and HOXC-AS2 expression. Then, by interfering with HOXC-AS2 or STAT1, the effects of HOXC-AS2 regulation of STAT1 on the TAM phenotype and STAT1/SOCS1 and STAT1/CIITA pathways were analyzed, and the proliferation and metastasis of NSCLC cells in the coculture system were also detected. Results showed that HOXC-AS2 expression in M2 macrophages and TAMs was significantly higher than that in M1 macrophages, and A549-exo promoted HOXC-AS2 expression and M2 polarization. Intervention HOXC-AS2 resulted in increased M1 marker expression, decreased M2 marker expression, and activation of STAT1/SOCS1 and STAT1/CIITA pathways in TAMs. In addition, HOXC-AS2 was mainly expressed in the cytoplasm of TAMs and could bind to STAT1. Further experiments confirmed that intervention HOXC-AS2 promoted the M1 polarization of TAMs by targeting STAT1 and weakened the promoting effects of TAMs on the proliferation and metastasis of NSCLC. In conclusion, HOXC-AS2 inhibited the activation of STAT1/SOCS1 and STAT1/CIITA pathways and promoted M2 polarization of TAMs by binding with STAT1, thus promoting NSCLC.

Effects of extracellular vesicles from adipose-derived stem cells on human keloid fibroblasts via the SOCS1/JAK2/STAT3 pathway.

BACKGROUND: Keloid represents a benign skin tumor with many cancer-like features. Extracellular vesicles (EVs) derived from human adipose-derived stem cells (hADSCs) play a role in cell migration of multiple diseases. AIMS: This study aimed to investigate the impact of hADSC-EVs on human keloid fibroblasts (HKFs). METHODS: hADSCs were cultured to the 3rd generation, and subsequently assessed for their osteogenic, adipogenic, and chondrogenic differentiative abilities using flow cytometry, alizarin red, oil red O, and alcian blue staining techniques. hADSC-EVs were isolated through ultracentrifugation and subsequently identified. HKFs at the 3rd generation were subjected to treatment with hADSC-EVs to observe their endocytosis of EVs by immunofluorescence. CCK-8, wound healing, and Transwell assays were performed to test HKF proliferation and migration. The levels of autophagy proteins, collagens, and Janus kinase 2 (JAK2) and Signal Transducer and Activator of Transcription 3 (STAT3) were determined through Western blot analysis. Suppressor of cytokine signaling 1 (SOCS1) expression was determined by RT-qPCR and Western blot. RESULTS: hADSC-EVs were successfully isolated from hADSCs. PKH67-labeled hADSC-EVs were observed to be endocytosed by HKFs, resulting the inhibition of HKF proliferation, migration, as well as a reduction in collagen deposition. hADSC-EVs carried SOCS1 into HKFs to suppress HKF autophagy. SOCS1 downregulation in hADSC-EVs partially nullified the inhibitory effect of hADSC-EVs on HKFs. hADSC-EV-carried SOCS1 inhibited the activation of the JAK2/STAT3 pathway. JAK2/STAT3 pathway activation partially abrogated the suppression of hADSC-EVs on the proliferation, migration, and collagen deposition of HKF. CONCLUSION: hADSC-EVs carried SOCS1 into HKFs and suppressed HKF autophagy, proliferation, migration, and collagen deposition by inactivating the JAK2/STAT3 pathway.