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.

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.

Suppressor of cytokine signaling-3 expression and its regulation in relation to inflammation in Chronic Obstructive Pulmonary Disease.

Background: The family of Suppressor of Cytokine Signaling (SOCS) acts as a controller of the duration and intensity of cytokine function by negatively regulating the JAK-STAT signaling pathway. SOCS' role in inflammatory diseases in animal models is well demonstrated. However, its role in the development of human disease is still under investigation. SOCS3 plays an important role in tumor development where its downregulation has been implicated in the pathogenesis of various solid tumors such as triple-negative breast cancer. Aim: The aim of this work was to study (1) the expression of SOCS3 in smokers' lungs and its relation to the degree of inflammation and (2) SOCS3 regulation by microRNA (miRNA) in alveolar-macrophage (AM)-derived extracellular vesicles (EVs) in bronchoalveolar lavage (BAL). Methods: Group A: 35 smokers' [19 with COPD (SC) and 16 without COPD (S)] and 9 nonsmokers (NS); SOCS3, TNFα in AM, and CD8+ T cells were quantified by immunohistochemistry, in lung tissue. Group B: additional 9 SC, 11 S, and 5 NS; AM-EVs expressing SOCS3 (CD14+SOCS3+) and SOCS3 suppressors miRNA-19a-3p and 221-3p in EVs were quantified by flow cytometry and PCR, in BAL. Results: The percentage of SOCS3+ AM was higher in SC [68 (6.6-99)%] and S [48 (8-100)%] than in NS [9.6 (1.9-61)%; p = 0.002; p = 0.03] and correlated with % of TNFα+AM (r = 0.48; p = 0.0009) and CD8+ T cells (r = 0.44; p = 0.0029). In BAL, the CD14+SOCS3+ EVs/µL were increased in SC [33 (21-74)] compared to S [16 (8-37); p = 0.03] and NS [9 (7-21); p = 0.003]. Conversely, miRNA-19a-3p and miRNA-221-3p expression were increased in S when compared to SC [19 (2-53) vs. 3 (0.6-8); p = 0.03 and 3 (0.005-9.6) vs. 0.2 (0.08-0.7); p = 0.05]. Conclusions: The suppressor function of SOCS3 in COPD seems to be overridden by other factors and does not follow the animal-model paradigm. Expression of SOCS3 in BAL macrophage-derived EVs might be useful to assess the degree of inflammation and possible progression of COPD. Downregulation of SOCS3, by miRNA, in smokers without COPD might contribute to the risk of developing cancer in these patients.

Identification of Hit Compounds Using Artificial Intelligence for the Management of Allergic Diseases.

This study aimed to identify and evaluate drug candidates targeting the kinase inhibitory region of suppressor of cytokine signaling (SOCS) 3 for the treatment of allergic rhinitis (AR). Utilizing an artificial intelligence (AI)-based new drug development platform, virtual screening was conducted to identify compounds inhibiting the SH2 domain binding of SOCS3. Luminescence assays assessed the ability of these compounds to restore JAK-2 activity diminished by SOCS3. Jurkat T and BEAS-2B cells were utilized to investigate changes in SOCS3 and STAT3 expression, along with STAT3 phosphorylation in response to the identified compounds. In an OVA-induced allergic rhinitis mouse model, we measured serum levels of total IgE and OVA-specific IgE, performed real-time PCR on nasal mucosa samples to quantify Th2 cytokines and IFN-γ expression, and conducted immunohistochemistry to analyze eosinophil levels. Screening identified 20 hit compounds with robust binding affinities. As the concentration of SOCS3 increased, a corresponding decrease in JAK2 activity was observed. Compounds 5 and 8 exhibited significant efficacy in restoring JAK2 activity without toxicity. Treatment with these compounds resulted in reduced SOCS3 expression and the reinstatement of STAT3 phosphorylation in Jurkat T and BEAS-2B cells. In the OVA-induced allergic rhinitis mouse model, compounds 5 and 8 effectively alleviated nasal symptoms and demonstrated lower levels of immune markers compared to the allergy group. This study underscores the promising nonclinical efficacy of compounds identified through the AI-based drug development platform. These findings introduce innovative strategies for the treatment of AR and highlight the potential therapeutic value of targeting SOCS3 in managing AR.

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.

Suppression of SOCS3 expression in macrophage cells: Potential application in diabetic wound healing.

Impaired polarization of M1 to M2 macrophages has been reported in diabetic wounds. We aimed to improve this polarization by down-regulation of expression of the "Suppressor of Cytokine Signaling 3" (SOCS3) gene in macrophages. Two oligodeoxynucleotide (ASO) sequences were designed against SOC3 mRNA and were loaded to mannosylated-polyethyleneimine (Man-PEI). The optimum N/P ratio for Man-PEI-ASO was determined to be 8 based on loading efficiency, particle size, zeta potential, cellular uptake and cytotoxicity assay. pH stability of ASO in Man-PEI-ASO and its protection from DNase I was confirmed. After in vitro treatment of macrophages with Man-PEI-ASO, SOCS3 was downregulated, SOCS1 upregulated, and SOCS1/SOCS3 ratio increased. Also, expressions of macrophage markers of M2 (IL-10, Arg1, CD206) increased and those of M1 (IL-1ß, NOS2, CD68) decreased, and secretion of pro-inflammatory cytokines (TNF-α and IL-1ß) decreased while that of anti-inflammatory cytokine IL-4 increased. All suggested a polarization into M2 phenotype. Finally, the Man-PEI-ASO was loaded in hydrogel and applied to a diabetic wound model in mice. It improved the healing to the level observed in non-diabetic wounds. We show that using antisense sequences against SOC3 mRNA, macrophage polarization could be directed into the M2 phenotype and healing of diabetic wound could be highly improved.

L-arginine attenuates Streptococcus uberis-induced inflammation by decreasing miR155 level.

L-arginine, as an essential substance of the immune system, plays a vital role in innate immunity. MiR155, a multi-functional microRNA, has gained importance as a regulator of homeostasis in immune cells. However, the immunoregulatory mechanism between L-arginine and miR155 in bacterial infections is unknown. Here, we investigated the potential role of miR155 in inflammation and the molecular regulatory mechanisms of L-arginine in Streptococcus uberis (S. uberis) infections. And we observed that miR155 was up-regulated after infection, accompanying the depletion of L-arginine, leading to metabolic disorders of amino acids and severe tissue damage. Mechanically, the upregulated miR155 mediated by the p65 protein played a pro-inflammatory role by suppressing the suppressor of cytokine signaling 6 (SOCS6)-mediated p65 ubiquitination and degradation. This culminated in a violently inflammatory response and tissue damage. Interestingly, a significant anti-inflammatory effect was revealed in L-arginine supplementation by reducing miR155 production via inhibiting p65. This work firstly uncovers the pro-inflammatory role of miR155 and an anti-inflammatory mechanism of L-arginine in S.uberis infection with a mouse mastitis model. Collectively, we provide new insights and strategies for the prevention and control of this important pathogen, which is of great significance for ensuring human food health and safety.

Marine sponge-derived alkaloid ameliorates DSS-induced IBD via inhibiting IL-6 expression through modulating JAK2-STAT3-SOCS3 pathway.

Cyanogramide (AC14), a novel alkaloid, isolated from the fermentation broth of the marine-derived Actinoalloteichus cyanogriseus. However, the exact role of AC14 in inflammatory bowel disease (IBD) is poorly understood. Our results demonstrated that AC14 exhibited significant inhibition of IL-6 release in THP-1 cells and a "Caco-2/THP-1" coculture system after stimulation with LPS for 24 h. However, no significant effect on TNF-α production was observed. Furthermore, in 2.5 % DSS-induced colitis mice, AC14 treatment led to improvement in body weight, colon length, and intestine mucosal barrier integrity. AC14 also suppressed serum IL-6 production and modulated dysregulated microbiota in the mice. Mechanistically, AC14 was found to inhibit the phosphorylation of Janus kinase (JAK) 2 and signal transducers and activators of transcription (STAT) 3, while simultaneously elevating the expression of suppressor of cytokine signaling (SOCS) 3, both in vivo and in vitro. These findings suggest that AC14 exerts its suppressive effects on IL-6 production in DSS-induced IBD mice through the JAK2-STAT3-SOCS3 signaling pathway. Our study highlights the potential of AC14 as a therapeutic agent for the treatment of IBD.

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.

The CUL5 E3 ligase complex negatively regulates central signaling pathways in CD8+ T cells.

CD8+ T cells play an important role in anti-tumor immunity. Better understanding of their regulation could advance cancer immunotherapies. Here we identify, via stepwise CRISPR-based screening, that CUL5 is a negative regulator of the core signaling pathways of CD8+ T cells. Knocking out CUL5 in mouse CD8+ T cells significantly improves their tumor growth inhibiting ability, with significant proteomic alterations that broadly enhance TCR and cytokine signaling and their effector functions. Chemical inhibition of neddylation required by CUL5 activation, also enhances CD8 effector activities with CUL5 validated as a major target. Mechanistically, CUL5, which is upregulated by TCR stimulation, interacts with the SOCS-box-containing protein PCMTD2 and inhibits TCR and IL2 signaling. Additionally, CTLA4 is markedly upregulated by CUL5 knockout, and its inactivation further enhances the anti-tumor effect of CUL5 KO. These results together reveal a negative regulatory mechanism for CD8+ T cells and have strong translational implications in cancer immunotherapy.

Aberrant expression of SOCS impairs the anti-leishmanial immune response.

Establishing a balance between Th1 and Th2 subsets and M1- and M2-type macrophages is essential for the control of Leishmania infection. The suppressors of cytokine secretion (SOCS) proteins, particularly SOCS1 and SOCS3, play a significant role in regulating cytokine-triggered signaling pathways, thereby impacting the macrophage-and effector T-cell mediated antileishmanial immune response. In addition to the pro-inflammatory cytokines, Leishmania-derived lipophosphoglycan (LPG) and CpG-DNA interact with TLR2 and TLR9 to trigger SOCS expression. The aberrant levels of SOCS1 and SOCS3 expression in Leishmania-infected macrophages impair macrophage-T-cell interaction perturbing the balance in macrophage subsets polarization. This hinders macrophage apoptosis and macrophage-mediated leishmanicidal activity, both support the establishment of infection and parasite replication. Furthermore, aberrant SOCS3 levels in T-cells disrupt Th1 differentiation and aid in parasite replication, lesion development, and pathological immune responses. Strategically, selective modulation of SOCS expression and function in immune effector cells may reduce parasite survival and prevent disease progression.

Transcriptional regulation of suppressors of cytokine signaling during infection with Mycobacterium tuberculosis in human THP-1-derived macrophages and in mice.

Mycobacterium tuberculosis (Mtb) infection leads to upregulation of Suppressors of Cytokine signaling (SOCS) expression in host macrophages (Mϕ). SOCS proteins inhibit cytokine signaling by negatively regulating JAK/STAT. We investigated this host-pathogen dialectic at the level of transcription. We used phorbol-differentiated THP-1 Mϕ infected with Mtb to investigate preferential upregulation of some SOCS isoforms that are known to inhibit signaling by IFN-γ, IL-12, and IL-6. We examined time kinetics of likely transcription factors and signaling molecules upstream of SOCS transcription, and survival of intracellular Mtb following SOCS upregulation. Our results suggest a plausible mechanism that involves PGE2 secretion during infection to induce the PKA/CREB axis, culminating in nuclear translocation of C/EBPß to induce expression of SOCS1. Mtb-infected Mϕ secreted IL-10, suggesting a mechanism of induction of STAT3, which may subsequently induce SOCS3. We provide evidence of temporal variation in SOCS isoform exspression and decay. Small-interfering RNA-mediated knockdown of SOCS1 and SOCS3 restored the pro-inflammatory milieu and reduced Mtb viability. In mice infected with Mtb, SOCS isoforms persisted across Days 28-85 post infection. Our results suggest that differential temporal regulation of SOCS isoforms by Mtb drives the host immune response towards a phenotype that facilitates the pathogen's survival.

SOCS2 inhibits hepatoblastoma metastasis via downregulation of the JAK2/STAT5 signal pathway.

Metastasis of hepatoblastoma (HB) is a key factor that impairs the prognosis and treatment of children. The suppressor of cytokine signaling 2 (SOCS2) is a classical negative feedback protein that regulates cytokine signal transduction and has been known to be downregulated in several tumor, but the molecular mechanisms of its involvement in HB metastasis are unknown. We found that SOCS2 was a gene down-regulated in hepatoblastoma and associated with HB metastasis through bioinformatics. The qRT-PCR, Western blot and IHC showed that SOCS2 was significantly lower in HB tissues. Clinicopathological correlation analysis revealed that low expression of SOCS2 was significantly correlated with tumor metastasis (P = 0.046) and vascular invasion (P = 0.028), associated with poor prognosis. Overexpression of SOCS2 inhibited the migration and invasion of hepatoblastoma cells, while knockdown of SOCS2 expression promoted these malignant phenotypes. In vivo studies revealed overexpression of SOCS2 inhibited the formation of lung metastasis. Up-regulation of SOCS2 in HB cell inhibited EMT and JAK2/STAT5. Conversely, down-regulation of SOCS2 promoted EMT and JAK2/STAT5. The addition of the JAK2 inhibitor Fedratinib partially reversed the effects of si-SOCS2 on HB cells. SOCS2 may inhibit the migration and invasion of HB cells by inhibiting the JAK2/STAT5 signaling pathway. These results may provide guiding significance for the clinical treatment of HB.

CTRP6 protects against ferroptosis to drive lung cancer progression and metastasis by destabilizing SOCS2 and augmenting the xCT/GPX4 pathway.

Lung cancer is a highly heterogeneous malignancy, and despite the rapid development of chemotherapy and radiotherapy, acquired drug resistance and tumor progression still occur. Thus, it is urgent to identify novel therapeutic targets. Our research aims to screen novel biomarkers associated with the prognosis of lung carcinoma patients and explore the potential regulatory mechanisms. We obtained RNA sequencing (RNA-seq) data of lung cancer patients from public databases. Clinical signature analysis, weighted gene coexpression network analysis (WGCNA) and the random forest algorithm showed that C1q/tumor necrosis factor-related protein-6 (CTRP6) is a core gene related to lung cancer prognosis, and it was determined to promote tumor proliferation and metastasis both in vivo and in vitro. Mechanistically, silencing CTRP6 was determined to promote xCT/GPX4-involved ferroptosis through functional assays related to lipid peroxidation, Fe2+ concentration and mitochondrial ultrastructure. By performing interactive proteomics analyses in lung tumor cells, we identified the interaction between CTRP6 and suppressor of cytokine signaling 2 (SOCS2) leading to SOCS2 ubiquitination degradation, subsequently enhancing the downstream xCT/GPX4 signaling pathway. Moreover, significant correlations between CTRP6-mediated SOCS2 and ferroptosis were revealed in mouse models and clinical specimens of lung cancer. As inducing ferroptosis has been gradually regarded as an alternative strategy to treat tumors, targeting CTRP6-mediated ferroptosis could be a potential strategy for lung cancer therapy.

IL4Rα and IL17A Blockade Rescue Autoinflammation in SOCS1 Haploinsufficiency.

By inhibition of JAK-STAT signaling, SOCS1 acts as a master regulator of the cytokine response across numerous tissue types and cytokine pathways. Haploinsufficiency of SOCS1 has recently emerged as a monogenic immunodysregulatory disease with marked clinical variability. Here, we describe a patient with severe dermatitis, recurrent skin infections, and psoriatic arthritis that harbors a novel heterozygous mutation in SOCS1. The variant, c.202_203delAC, generates a frameshift in SOCS1, p.Thr68fsAla*49, which leads to complete loss of protein expression. Unlike WT SOCS1, Thr68fs SOCS1 fails to inhibit JAK-STAT signaling when expressed in vitro. The peripheral immune signature from this patient was marked by a redistribution of monocyte sub-populations and hyper-responsiveness to multiple cytokines. Despite this broad hyper-response across multiple cytokine pathways in SOCS1 haploinsufficiency, the patient's clinical disease was markedly responsive to targeted IL4Rα- and IL17-blocking therapy. In accordance, the mutant allele was unable to regulate IL4Rα signaling. Further, patient cells were unresponsive to IL4/IL13 while on monoclonal antibody therapy. Together, this study reports a novel SOCS1 mutation and suggests that IL4Rα blockade may serve as an unexpected, but fruitful therapeutic target for some patients with SOCS1 haploinsufficiency.

Role of Cytokine-Inducible SH2 Domain-Containing (CISH) Protein in the Regulation of Erythropoiesis.

The cytokine-inducible SH2 domain-containing (CISH) protein was the first member of the suppressor of cytokine signaling (SOCS) family of negative feedback regulators discovered, being identified in vitro as an inducible inhibitor of erythropoietin (EPO) signaling. However, understanding of the physiological role played by CISH in erythropoiesis has remained limited. To directly assess the function of CISH in this context, mice deficient in CISH were characterized with respect to developmental, steady-state, and EPO-induced erythropoiesis. CISH was strongly expressed in the fetal liver, but CISH knockout (KO) mice showed only minor disruption of primitive erythropoiesis. However, adults exhibited mild macrocytic anemia coincident with subtle perturbation particularly of bone marrow erythropoiesis, with EPO-induced erythropoiesis blunted in the bone marrow of KO mice but enhanced in the spleen. Cish was expressed basally in the bone marrow with induction following EPO stimulation in bone marrow and spleen. Overall, this study indicates that CISH participates in the control of both basal and EPO-induced erythropoiesis in vivo.

Synthetic High-Density Lipoprotein-Based Nanomedicine to Silence SOCS1 in Tumor Microenvironment and Trigger Antitumor Immunity against Glioma.

Immunotherapies have shed light on the treatment of many cancers, but have not improved the outcomes of glioma (GBM). Here, we demonstrated that suppressor of cytokine signaling 1 (SOCS1) was associated with the GBM-associated immunosuppression and developed a multifunctional nanomedicine, which silenced SOCS1 in the tumor microenvironment (TME) of GBM and triggered strong antitumor immunity against GBM. Synthetic high-density lipoprotein (sHDL) was selected as the nanocarrier and a peptide was used to facilitate the blood-brain-barrier (BBB) penetration. The nanocarrier was loaded with a small interfering RNA (siRNA), a peptide, and an adjuvant to trigger antitumor immunity. The nanomedicine concentrated on the TME in vivo, further promoting dendritic cell maturation and T cell proliferation, triggering strong cytotoxic T lymphocyte responses, and inhibiting tumor growth. Our work provides an alternative strategy to simultaneously target and modulate the TME in GBM patients and points to an avenue for enhancing the efficacy of immunotherapeutics.

Sequential inspiratory muscle exercise-noninvasive positive pressure ventilation alleviates oxidative stress in COPD by mediating SOCS5/JAK2/STAT3 pathway.

BACKGROUND: Pulmonary rehabilitation training is of great significance for the prognosis of chronic obstructive pulmonary disease (COPD) patients. The purpose of this study was to investigate the therapeutic effect and pathway of a new sequential noninvasive positive pressure ventilation (NIPPV) + inspiratory muscle training (IMT) therapy. METHODS: A total of 100 COPD patients were enrolled and randomly divided into oxygen therapy (OT), NIPPV, IMT and sequential (NIPPV + IMT) group. Lung function, exercise endurance, quality of life, and dyspnea symptoms were examined and recorded. Then, reactive oxygen species (ROS), malonaldehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH) levels were detected by enzyme-linked immunoassay, and suppressor of cytokine signaling 5 (SOCS5)/janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway expression changes were detected by quantitative real time-polymerase chain reaction (qRT-PCR) and western blot. A mouse model of COPD was then established to further verify the effects of SOCS5/JAK2/STAT3 pathways on lung function and oxidative stress. RESULTS: After 8 weeks of treatment, NIPPV, IMT or sequential (NIPPV + IMT) significantly improved exercise endurance, quality of life and dyspnea, reduced oxidative stress, promoted SOCS5 expression and inhibited the activation of JAK2/STAT3 pathway, and no significant effect was observed on lung function of COPD patients. Notably, sequential (NIPPV + IMT) showed better therapeutic outcomes than either IMT or NIPPV alone. Moreover, results at the animal level showed that overexpression of SOCS5 significantly reduced pulmonary inflammatory infiltration, pathological changes and oxidative stress levels in COPD mice, enhanced lung function, and inhibited the activation of JAK2/STAT3 pathway. CONCLUSION: Our results elucidated that sequential (NIPPV + IMT) significantly relieved COPD development by regulating SOCS5/JAK2/STAT3 signaling-mediated oxidative stress.

SOCS1 acts as a ferroptosis driver to inhibit the progression and chemotherapy resistance of triple-negative breast cancer.

OBJECTIVES: Ferroptosis is involved in many types of cancers, including triple-negative breast cancer (TNBC). Suppressor of cytokine signaling 1 (SOCS1) has recently been implicated as a regulator of ferroptosis. We aim to explore whether targeting SOCS1 is a potential therapeutic strategy for TNBC therapy. METHODS: Stable cell lines were constructed using lentivirus transfection. Cell viability was determined using CCK-8 and cell colony formation assays, respectively. Assays including lactate dehydrogenase release, lipid peroxidation and malondialdehyde assays were conducted to evaluate ferroptosis. Real-time quantitative polymerase chain reaction and western blotting were performed to evaluate mRNA and protein expression, respectively. A xenograft animal model was established by subcutaneous injection of cells into the flank. RESULTS: Our results showed that SOCS1 overexpression inhibited cell proliferation and induced ferroptosis in TNBC cells, while SOCS1 knockdown promoted cell proliferation and reduced ferroptosis. We also found that SOCS1 regulated ferroptosis by modulating GPX4 expression. Furthermore, SOCS1 regulated cisplatin resistance in TNBC cells by promoting ferroptosis. Our in vivo data suggested that SOCS1 regulated tumor growth and cisplatin resistance in vivo. CONCLUSIONS: SOCS1 inhibits the progression and chemotherapy resistance of TNBC by regulating GPX4 expression.

YY1-regulated lncRNA SOCS2-AS1 suppresses HCC cell stemness and progression via miR-454-3p/CPEB1.

BACKGROUND: Cancer stem cells are one fundamental reason for the high recurrence rate of hepatocellular carcinoma (HCC) and its resistance to treatment. This study explored the mechanism by which SOCS2-AS1 affects HCC cell stemness. METHODS: Stem cells of HCC cell lines Huh7 and SNU-398 were sorted as NANOG-positive by flow cytometry. Stem cell sphere formation ability was detected. Stem cell viability, migration, invasion, and apoptosis were assessed by colony formation assays, Transwell assays, wound-healing assays, and TUNEL assays, respectively. The binding sites for SOCS2-AS1, miR-454-3p, miR-454-3p, and CPEB1 mRNA were assessed by dual-luciferase reporter assays. Quantitative real-time PCR (qPCR) and Western blot studies were performed to evaluate gene expression levels. ChIP and EMSA assays were conducted to confirm that YY1 binds with the SOCS2-AS1 promoter. A subcutaneous xenograft model was used to verify results in vivo. Tumor tissues were analyzed by H&E and TUNEL staining. RESULTS: SOCS2-AS1 was expressed at low levels in NANOG+ HCC stem cells, and HCC patients with a high level of SOCS2-AS1 expression had a higher survival rate. SOCS2-AS1 inhibited HCC cell stemness, migration, and invasion, and increased the cisplatin sensitivity of HCC cells by regulating miR-454-3p/CPEB1. YY1 was confirmed as a transcription factor of SOCS2-AS1, and served to inhibit SOCS2-AS1 transcription. YY1 knockdown suppressed HCC stemness via SOCS2-AS1. The role of SOCS2-AS1 was confirmed in a subcutaneous xenograft model, and SOCS2-AS1 overexpression enhanced the inhibitory effect of cisplatin on HCC in vivo. CONCLUSIONS: YY1-regulated lncRNA SOCS2-AS1 suppresses HCC cell stemness and progression via miR-454-3p/CPEB1.