Wuqi Song

MiR-122 modulates type I interferon expression through blocking suppressor of cytokine signaling 1

MiR-122 is a liver-specific miRNA. Recent studies demonstrated that the interferon (IFN) therapy efficacy is poor in the hepatitis C virus (HCV)-infected patients with lower miR-122 abundance in the livers. The hepatocarcinoma patients also have low miR-122 levels in their livers. We previously found that the IFN expression was reduced when miR-122 was knocked down in human oligodendrocytes. The mechanism is unclear. In this study, the miR-122-abundant cell Huh7 was used to explore the regulatory mechanism of miR-122 on type I IFN expression. We found that miR-122 significantly increased the type I IFN expression in Huh7 cells, while knocking down miR-122 decreased the type I IFN expression. By screening potential miR-122 targets among the negative regulators in IFN signaling pathways, we found that there were putative miR-122 targets in the suppressor of cytokine signaling 1 (SOCS1) mRNA. Over-expressing miR-122 decreased the SOCS1 expression by 50.55% in Huh7 cells, while knocking down miR-122 increased SOCS1 expression by 62.56%. Using a green fluorescence protein (EGFP) fused SOCS1-expressing plasmid, the SOCS1-EGFP fluorescence intensity and protein were lower in miR-122 mimic-treated cells than those in mock-miRNA-treated cells, while miR-122 knockdown significantly increased the SOCS1-EGFP fluorescence intensity and protein expression. Mutations in the nt359-nt375 region abandoned the impact of miR-122 on SOCS1-EGFP expression. Taken together, SOCS1 is a target of miR-122. MiR-122 can regulate the type I IFN expression through modulating the SOCS1 expression.

Modulation of miR-122 on persistently Borna disease virus infected human oligodendroglial cells

Using RNAhybrid software we found the predicted binding of complementary sequences between miR-122 and viral mRNAs, may be important for the antiviral effect of miR-122 on Borna disease virus (BDV). A moderate expression of miR-122 was identified in human oligodendroglial cells (OL), but with a much lower level of miR-122 in BDV persistent infection (OL/BDV) and cells transfected with BDV gene expression vectors. Over-expression of miR-122 and specific blocking experiments demonstrated that miR-122 was able to specifically inhibit BDV protein synthesis, viral gene replication and transcription, and induce the secretion/synthesis of interferon (IFN) in OL and OL/BDV cells. The abolishment of miR-122 by AMO-122 inhibited endogenous IFN induction by IFN-beta. These results indicate that miR-122 can exert direct antiviral function by inhibiting BDV translation and replication on one hand, while acting indirectly through IFN to increase the host innate immunity to modulate the virus-host interactions on the other hand.

Borna disease virus encoded phosphoprotein inhibits host innate immunity by regulating miR-155

It has been reported that the Borna disease virus (BDV) encoded phosphoprotein (P protein) can inhibit the activity of Traf family member-associated NF-kappaB activator (TANK)-binding kinase 1 (TBK-1), thus preventing the induction of type I interferon (IFN). However, the effects of microRNA on the regulation of BDV infection and the hosts immune response have not been characterized. miR-155 was predicted to be complementary to the BDV P mRNA by RNAhybrid software. Here, we showed that miR-155 was down-regulated in BDV persistently infected human oligodendroglial (OL/BDV) cells and that the BDV P protein, but not the X protein, directly inhibited miR-155 expression in cells. When miR-155 was over-expressed, the inhibition of type I IFNs by BDV in cells was reversed, and the expression of type I IFNs was increased. When miR-155 expression was specifically blocked, cellular IFN expression and the induction of IFN by poly I:C treatment were suppressed. Furthermore, miR-155 promoted type I IFN production by targeting suppressor of cytokine signaling 1 (SOCS1) and SOCS3. Mutations in the nt1138-nt1158 region of SOCS3 abandoned the impact of miR-155 on the expression of SOCS3-enhanced green fluorescent protein (EGFP). The levels of BDV P mRNA and protein were significantly decreased in OL/BDV cells when miR-155 was over-expressed; however, miR-155-mutation did not affect the expression of BDV P-EGFP. Thus, BDV persistent infection inhibited the expression of type I IFNs through the suppression of miR-155, and miR-155 played an important immune regulatory role in BDV persistent infection.

Modulation of miR‑122 expression affects the interferon response in human hepatoma cells

Type I interferon (IFN) is believed to play significant roles in limiting tumor growth. It has been revealed that the induction of endogenous IFN expression is one of the key mechanisms for successful IFN therapy. However, recent studies have shown that the efficacy of type I IFN therapy has limitations in the clinical treatment of certain tumors, including hepatocellular carcinoma (HCC). It has been revealed that the expression of miR‑122 is significantly decreased in HCC and that restoration of miR‑122 expression may improve the prognosis of this condition. Previous studies also showed that patients with low miR‑122 levels in the liver responded poorly to the IFN therapy. We previously identified that the IFN expression was reduced when miR‑122 was suppressed in human oligodendrocytes. Based on these studies, it was hypothesized that the expression of miR‑122 may modulate the endogenous IFN expression and subsequently affect the treatment outcome of IFN therapy for HCC. The results of the present study showed that miR‑122‑abundant Huh7 cells responded more significantly than miR‑122‑deficient HepG2 cells when treated with exogenous IFN. Upregulation of miR‑122 significantly increased the ability of exogenous IFN‑induced IFN expression, while downregulation of miR‑122 decreased this ability. These data indicate that a high level of miR‑122 expression may promote the expression of type I IFN induced by exogenous IFNs and further contribute to IFN therapy for HCC.

Differential diagnosis of systemic lupus erythematosus and rheumatoid arthritis with complements C3 and C4 and C-reactive protein.

The aim of this study was to analyze the changes in complements C3 and C4 and C-reactive protein (CRP) in patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), and to evaluate the role of these indices in the differential diagnosis of SLE and RA. The first 347 patients with SLE, 382 patients with RA and 66 patients with erythema nodosum were selected for the measurement of complement and CRP levels in the serum, the erythema nodosum patients were the control group. The roles of the complements and CRP in the differential diagnosis and disease activity evaluation of SLE and RA were analyzed with SPSS 13.0. Complement C3 and C4 levels were significantly reduced in patients with SLE compared with those in the control group. However, in RA patients, the CRP level was increased. In addition, the levels of complements C3 and C4 in patients with SLE were much lower than those in patients with RA and the level of CRP in RA patients was much higher than that in patients with SLE. The reduction of complement C3 levels in SLE patients, and increase of CRP and complement C4 in patients with RA were associated with a higher risk of joint pain, butterfly rash and oral ulcer. These results show that the disease activity of SLE was negatively correlated with complement C3 and C4, and the disease activity of RA was positively correlated with CRP. With the increase in disease activity, the levels of complements C3 and C4 in patients with SLE were gradually reduced and the level of CRP in patients with RA was increased. There were distinctive differences in the levels of complements C3 and C4 and CRP between SLE and RA patients. The differences are useful in disease activity evaluation and the differential diagnosis of the two diseases that have similar symptoms.

Borna disease virus nucleoprotein inhibits type I interferon induction through the interferon regulatory factor 7 pathway

The expression of type I interferon (IFN) is one of the most potent innate defences against viral infection in higher vertebrates. Borna disease virus (BDV) establishes persistent, noncytolytic infections in animals and in cultured cells. Early studies have shown that the BDV phosphoprotein can inhibit the activation of type I IFN through the TBK1-IRF3 pathway. The function of the BDV nucleoprotein in the inhibition of IFN activity is not yet clear. In this study, we demonstrated IRF7 activation and increased IFN-α/β expression in a BDV-persistently infected human oligodendroglia cell line following RNA interference-mediated BDV nucleoprotein silencing. Furthermore, we showed that BDV nucleoprotein prevented the nuclear localisation of IRF7 and inhibited endogenous IFN induction by poly(I:C), coxsackie virus B3 and IFN-β. Our findings provide evidence for a previously undescribed mechanism by which the BDV nucleoprotein inhibits type I IFN expression by interfering with the IRF7 pathway.

Chlorpromazine protects against apoptosis induced by exogenous stimuli in the developing rat brain.

Background Chlorpromazine (CPZ), a commonly used antipsychotic drug, was found to play a neuroprotective role in various models of toxicity. However, whether CPZ has the potential to affect brain apoptosis in vivo is still unknown. The purpose of this study was to investigate the potential effect of CPZ on the apoptosis induced by exogenous stimuli. Methodology The ethanol treated infant rat was utilized as a valid apoptotic model, which is commonly used and could trigger robust apoptosis in brain tissue. Prior to the induction of apoptosis by subcutaneous injection of ethanol, 7-day-old rats were treated with CPZ at several doses (5 mg/kg, 10 mg/kg and 20 mg/kg) by intraperitoneal injection. Apoptotic cells in the brain were measured using TUNEL analysis, and the levels of cleaved caspase-3, cytochrome c, the pro-apoptotic factor Bax and the anti-apoptotic factor Bcl-2 were assessed by immunostaining or western blot. Findings Compared to the group injected with ethanol only, the brains of the CPZ-pretreated rats had fewer apoptotic cells, lower expression of cleaved caspase-3, cytochrome c and Bax, and higher expression of Bcl-2. These results demonstrate that CPZ could prevent apoptosis in the brain by regulating the mitochondrial pathway. Conclusions CPZ exerts an inhibitory effect on apoptosis induced by ethanol in the rat brain, intimating that it may offer a means of protecting nerve cells from apoptosis induced by exogenous stimuli.

The roles and applications of autoantibodies in progression, diagnosis, treatment and prognosis of human malignant tumours

The existence of autoantibodies towards an individuals own proteins or nucleic acids has been established for more than 100years, and for a long period, these autoantibodies have been believed to be closely associated with autoimmune diseases. However, in recent years, researchers have become more interested in the role and application of autoantibodies in progression, diagnosis, treatment and prognosis of human malignant tumours. Over the past few decades, numerous epidemiological studies have shown that the risk of certain cancers is significantly altered (increased or decreased) in patients with autoimmune diseases, which suggests that autoantibodies may play either promoting or suppressing roles in cancer progression. The idea that autoantibodies are directly involved in tumour progression gains special support by the findings that some antibodies secreted by a variety of cancer cells can promote their proliferation and metastasis. Because the cancer cells generate cell antigenic changes (neoantigens), which trigger the immune system to produce autoantibodies, serum autoantibodies against tumour-associated antigens have been established as a novel type of cancer biomarkers and have been extensively studied in different types of cancer. The autoantibodies as biomarkers in cancer diagnosis are not only more sensitive and specific than antigens, but also could appear before clinical evidences of the tumours, thus disclosing them. The observations that cancer risk is lower in patients with some autoimmune diseases suggest that certain autoantibodies may be protective from certain cancers. Moreover, the presence of autoantibodies in healthy individuals implies that it could be safe to employ autoantibodies to treat cancer. Of note, an autoantibodies derived from lupus murine model received much attention due to their selective cytotoxicity for malignant tumour cell without harming normal ones. These studies showed the therapeutic value of autoantibodies in cancer. In this review, we revisited the pathological or protective role of autoantibodies in cancer progression, summarize the application of autoantibodies in cancer diagnosis and prognosis, and discuss the value of autoantibodies in cancer therapy. The studies established to date suggest that autoantibodies not only regulate cancer progression but also promise to be valuable instruments in oncological diagnosis and therapy.

Over-expression of mitochondrial antiviral signaling protein inhibits coxsackievirus B3 infection by enhancing type-I interferons production

BackgroundRecent studies have revealed that Mitochondrial Antiviral Signaling (MAVS) protein plays an essential role in the inhibition of viral infection through type I interferon (IFN) pathway. It has been shown that 3C (pro) cysteine protease of coxsackievirus B3 (CVB3) cleaves MAVS to inhibit type I IFNs induction. Other workers also found that MAVS knock-out mice suffered CVB3 susceptibility and severe histopathological change. Accordingly,our experiments were designed to explore the protection of over-expressing MAVS against CVB3 infection and the possible mechanism.ResultsIn this study, HeLa cells (transfected with MAVS constructs pre- or post- exposure to CVB3) were used to analyze the function of exogenous MAVS on CVB3 infection. The results revealed that though CVB3 infection induced production of type I IFNs, viral replication and cell death were not effectively inhibited. Similarly, exogenous MAVS increased type I IFNs moderately. Morever, we observed robust production of type I IFNs in CVB3 post-infected HeLa cells thereby successfully inhibiting CVB3 infection, as well formation of cytopathic effect (CPE) and cell death. Finally, introduction of exogenous MAVS into CVB3 pre-infected cells also restricted viral infection efficiently by greatly up-regulating IFNs.ConclusionsIn summary, exogenous MAVS effectively prevents and controls CVB3 infection by modulating and promoting the production of type I IFNs. The IFNs level in MAVS over-expressing cells is still tightly regulated by CVB3 infection. Thus, the factors that up-regulate MAVS might be an alternative prescription in CVB3-related syndromes by enhancing IFNs production.

Modeling using clinical examination indicators predicts interstitial lung disease among patients with rheumatoid arthritis

Interstitial lung disease (ILD) is a severe extra-articular manifestation of rheumatoid arthritis (RA) that is well-defined as a chronic systemic autoimmune disease. A proportion of patients with RA-associated ILD (RA-ILD) develop pulmonary fibrosis (PF), resulting in poor prognosis and increased lifetime risk. We investigated whether routine clinical examination indicators (CEIs) could be used to identify RA patients with high PF risk. A total of 533 patients with established RA were recruited in this study for model building and 32 CEIs were measured for each of them. To identify PF risk, a new artificial neural network (ANN) was built, in which inputs were generated by calculating Euclidean distance of CEIs between patients. Receiver operating characteristic curve analysis indicated that the ANN performed well in predicting the PF risk (Youden index = 0.436) by only incorporating four CEIs including age, eosinophil count, platelet count, and white blood cell count. A set of 218 RA patients with healthy lungs or suffering from ILD and a set of 87 RA patients suffering from PF were used for independent validation. Results showed that the model successfully identified ILD and PF with a true positive rate of 84.9% and 82.8%, respectively. The present study suggests that model integration of multiple routine CEIs contributes to identification of potential PF risk among patients with RA.