Expression of SOCS1 and SOCS3 Genes in Interferon-Treated and Direct-Acting Antiviral Drugs-Treated Hepatitis C Patients

SOCSs: important regulators of host cell susceptibility or resistance to viral infection

Suppressors of cytokine signaling (SOCSs) are implicated in viral infection and host antiviral innate immune response. Recent studies demonstrate that viruses can hijack SOCSs to inhibit Janus kinase-signal transducers and activators of transcription (JAK-STAT) pathway, block the production and signaling of interferons (IFNs). At the same time, viruses can hijack SOCS to regulate non-IFN factors to evade antiviral response. Host cells can also regulate SOCSs to resist viral infection. The competition of the control of SOCSs may largely determine the fate of viral infection and the susceptibility or resistance of host cells, which is of significance for development of novel antiviral therapies targeting SOCSs. Accumulating evidence reveal that the regulation and function of SOCSs by viruses and host cells are very complicated, which is determined by characteristics of both viruses and host cell types. This report presents a systematic review to evaluate the roles of SOCSs in viral infection and host antiviral responses. One of messages worth attention is that all eight SOCS members should be investigated to accurately characterize their roles and relative contribution in each viral infection, which may help identify the most effective SOCS to be used in "individualized" antiviral therapy.

Suppressors of Cytokine Signaling and Hepatocellular Carcinoma

Simple Summary

Hepatocellular carcinoma (HCC) is a common malignancy worldwide. The HCC generally develops in the liver of patients already suffering from chronic liver disease. There have been significant advances in both the curative and palliative treatment of HCC. Although liver resection is a curative treatment for HCC, its indication is often limited due to an impaired liver function reservoir. There is still a need to understand how to control liver regeneration after resection and find better cancer immunotherapy and anticancer drugs for advanced HCC. Suppressors of cytokine signaling (SOCS) negatively regulate cytokine signaling related to cell proliferation, differentiation, and immune response; therefore, SOCS are thought to play an important role in HCC development and liver regeneration.

Abstract

Cytokines are secreted soluble glycoproteins that regulate cellular growth, proliferation, and differentiation. Suppressors of cytokine signaling (SOCS) proteins negatively regulate cytokine signaling and form a classical negative feedback loop in the signaling pathways. There are eight members of the SOCS family. The SOCS proteins are all comprised of a loosely conserved N-terminal domain, a central Src homology 2 (SH2) domain, and a highly conserved SOCS box at the C-terminus. The role of SOCS proteins has been implicated in the regulation of cytokines and growth factors in liver diseases. The SOCS1 and SOCS3 proteins are involved in immune response and inhibit protective interferon signaling in viral hepatitis. A decreased expression of SOCS3 is associated with advanced stage and poor prognosis of patients with hepatocellular carcinoma (HCC). DNA methylations of SOCS1 and SOCS3 are found in HCC. Precise regulation of liver regeneration is influenced by stimulatory and inhibitory factors after partial hepatectomy (PH), in particular, SOCS2 and SOCS3 are induced at an early time point after PH. Evidence supporting the important role of SOCS signaling during liver regeneration also supports a role of SOCS signaling in HCC. Immuno-oncology drugs are now the first-line therapy for advanced HCC. The SOCS can be potential targets for HCC in terms of cell proliferation, cell differentiation, and immune response. In this literature review, we summarize recent findings of the SOCS family proteins related to HCC and liver diseases.

Clinical Correlation of Blood Cells with Suppression of Cytokine Signaling Gene Expression in Hepatitis C Virus-Infected Patients

Both innate and adaptive immune responses of host are regulated by fine balance between negative and positive signals to ensure their termination and onset on entry of pathogens. Suppressor of cytokine signaling (SOCS) genes inhibit cytokine signaling pathways and regulate innate and adaptive immunity. SOCS genes perform their function by positive and negative regulation of macrophages, development and differentiation of T cells, and activation of dendritic cells. Although the role of SOCS1 and SOCS3 genes in hepatitis C virus (HCV) patients has been well studied, the correlation of SOCS1 gene expression with complete blood count in HCV-positive patients has not been established yet. We observed a weak positive correlation of SOCS1 gene expression with hemoglobin (Hb) and platelet count, whereas leukocytes were negatively correlated with the expression. This study also provides a comparative analysis of complete blood count between healthy subjects and HCV-positive subjects. The findings suggest that Hb and platelet count were significantly lower (P < 0.0001) in HCV patients than in healthy subjects.

Clinical correlation of liver function tests with suppression of cytokine signaling (SOCS1) gene expression in HCV infected patients: A real-world clinical experience

Hepatitis C virus (HCV) is the leading cause of chronic liver complications globally and suppressor of cytokine signaling-1 (SOCS-1) is a gene triggered by cytokines that activates transcription of the JAK/STAT signal transduction pathway and negatively regulates Janus kinase-signal transducer. Several studies have shown that the expression of SOCS1 and SOCS3 genes negatively regulate the response of HCV infection to interferon therapy and interferon-free regimens. It has been reported that liver function enzymes elevate in CHC patients but the association of SOCS1 gene expression with LFTs haven't been studied. This study recruited 114 CHC patients and 112 normal healthy participants and analyzed the correlation of SOCS1 gene expression and liver function enzymes (LFEs). Herein, we observed that the expression of SOCS1 gene had a positive correlation with LFEs.

Role of SOCS1 Gene in Chronic Hepatitis C Virus Patients: A Mini-Review

Hepatitis C virus (HCV) is a global health problem, with an estimated bioburden of >180 million. Every year about 350,000 people die from HCV-associated liver complications such as cirrhosis and cancer (e.g., hepatocellular carcinoma). Pakistan has the second highest prevalence of HCV. Treatment of this life-threatening disease has been a challenge, but recent developments in direct-acting antivirals have offered hope to many. Although direct-acting antivirals have dramatically improved viral clearance, their exorbitant costs put them out of reach for patients in developing countries. Thus, interferon therapy is still being used in Pakistan. Specifically, interferon-stimulating genes can alter treatment response. For example, interferons induce expression of many antiviral genes through signal transducer and activator of transcription/Janus kinase signaling. Suppressor of cytokine signaling genes play an eminent role in the inhibition of cytokine signaling pathways and regulation of both adaptive and innate immunity. The present review examines expression of suppressor of cytokine signaling-1 in HCV-treated patients.

Prevalence of thyroid stimulating hormone dysfunction among sofosbuvir-treated HCV-infected patients: A real-world clinical experience

Thyroid dysfunctions occur frequently among hepatitis C virus (HCV)-infected patients. Accumulating evidence has shown the higher incidence of thyroid dysfunctions in interferon-treated patients that was previously the standard of care therapy. However, the prevalence of thyroid disorders has not been studied in the recently developed interferon-free regimens or direct-acting antiviral (DAA) drugs-treated patients. We recruited 37 patients who had just completed 6 months long sofosbuvir-based treatment, and 26 interferon-treated patients were also included in the study. Serum thyrotropin level of all participants was measured using VIDAS. We observed thyroid dysfunctions in both pegylated interferon-experienced and DAA drug-experienced patients but the prevalence of hyperthyroidism was found significantly higher in patients treated with interferon-based regimen as compared with interferon-free regimens. This high prevalence of hypothyroidism in patients with HCV posttreatment highlights the need for regular periodic screening of patients during the treatment.