Differential expression profile of long noncoding RNAs in chronic HBV infection: New insights into pathogenesis

Potential roles of microRNAs and long noncoding RNAs as diagnostic, prognostic and therapeutic biomarkers in coronary artery disease

Coronary artery disease (CAD), which is mainly caused by atherosclerotic processes in coronary arteries, became a significant health issue. MicroRNAs (miRNAs), and long noncoding RNAs (lncRNAs), have been shown to be stable in plasma and could thereby be adopted as biomarkers for CAD diagnosis and treatment. MiRNAs can regulate CAD development through different pathways and mechanisms, including modulation of vascular smooth muscle cell (VSMC) activity, inflammatory responses, myocardial injury, angiogenesis, and leukocyte adhesion. Similarly, previously studies have indicated that the causal effects of lncRNAs in CAD pathogenesis and their utility in CAD diagnosis and treatment, has been found to lead to cell cycle transition, proliferation dysregulation, and migration in favour of CAD development. Differential expression of miRNAs and lncRNAs in CAD patients has been identified and served as diagnostic, prognostic and therapeutic biomarkers for the assessment of CAD patients. Thus, in the current review, we summarize the functions of miRNAs and lncRNAs, which aimed to identify novel targets for the CAD diagnosis, prognosis, and treatment.

Identification of plasma lncRNA-ATB levels in hepatitis B virus-related cirrhosis and non-cirrhotic chronic hepatitis B patients

Long non-coding RNA-ATB (LncRNA-ATB) which is activated by transforming growth factor-β (TGF-β), is a key regulator of TGF-β signaling pathway. TGF-β plays an important role in various pathogenic processes, from inflammation and fibrosis to cirrhosis and cancer. In this study, we evaluated the plasma levels of lncRNA-ATB in patients with hepatitis B virus (HBV)-related cirrhosis and non-cirrhotic patients with chronic hepatitis B (CHB) and investigated the clinical values. Plasma samples were collected from 44 HBV-related cirrhosis patients, 45 non-cirrhotic CHB and 75 healthy controls. Briefly, after total RNA extraction and cDNA synthesis, quantitative real-time PCR (qPCR) was performed to detect plasma lncRNA-ATB levels. Results show the plasma levels of lncRNA-ATB in HBV-related cirrhosis patients were significantly higher in comparison to healthy controls (Fold change=2.60, p value=0.04). Also, we determined plasma levels of lncRNA-ATB as a specific biomarker of HBV-related cirrhosis (AUC=0.65, p value=0.03, Sensitivity 61.36%; Specificity 70.00%). In addition to, we investigated the plasma levels of lncRNA-ATB in non-cirrhotic CHB patients were significantly lower than healthy controls (Fold change= 0.33, p value=0.01). We also indicated plasma lncRNA-ATB levels were as a sensitive biomarker for diagnosis of non-cirrhotic CHB patients compared with healthy (AUC=0.66, p value=0.00, Sensitivity 71.11%; Specificity 57.78%). According to our results, circulating lncRNA-ATB has good specificity for diagnosing hepatitis B virus (HBV)-related cirrhosis and good sensitivity for diagnosis of non-cirrhotic chronic hepatitis B (CHB) patients.

Identification and characterization of lncRNA AP000253 in occult hepatitis B virus infection

BACKGROUND

Recent studies suggest that lncRNAs may play significant roles in the development of hepatitis B virus (HBV) infection. However, as a special stage of HBV infection, the lncRNA expression in occult HBV infection (OBI) remains unclear.

METHODS

The plasma level of 15 HBV infection-related lncRNAs was initially detected using qRT-PCR in 10 OBI and 10 healthy controls (HCs) in discovery phase. Significantly dysregulated lncRNAs were subsequently validated in another 64 OBI, 20 HCs, 31 chronic hepatitis B (CHB) and 20 asymptomatic HBsAg carriers (ASC). Moreover, the AP000253 expression in liver tissues and its potential biological functions in HBV infection were further investigate with public transcriptomic data and HBV-expressing cell lines.

RESULTS

Among candidate lncRNAs, the plasma level of AP000253 decreased significantly in OBI, ASC and CHB patients compared to HCs, while no difference was found among OBI, ASC and CHB patients. In liver tissues, similar AP000253 expression was also observed from the GSE83148 dataset, while that in HBV-expressing hepatoma cells was opposite. ROC curve analysis indicated that plasma AP000253 yielded an AUC of 0.73 with 60% sensitivity and 75% specificity when differentiating OBI from HCs, but it could not specifically separate the stage of chronic HBV infection. Furthermore, functional experiments suggested that AP000253 could promote HBV transcription and replication in hepatoma cell lines.

CONCLUSIONS

AP000253 might be involved in HBV replication, and be served as a potential biomarker for HBV infection. In the setting of blood donations, plasma AP000253 would be more useful to moderately distinguish OBI in HBsAg-negative donors. However, the AP000253 expression in liver tissues and associated molecular mechanism of HBV infection deserve further study in future.

lncRNA-HEIM Facilitated Liver Fibrosis by Up-Regulating TGF-β Expression in Long-Term Outcome of Chronic Hepatitis B

Background

Chronic liver fibrosis is an inevitable stage for the development of patients with chronic hepatitis B (CHB). However, anti-fibrotic therapies have been unsuccessful so far. The biological functions and molecular mechanisms of long non-coding RNAs (lncRNAs) in the host immune system during chronic hepatitis B virus (HBV) infection, especially in fibrosis, are still largely unknown.

Method

The total RNA of peripheral blood mononuclear cells (PBMCs) from asymptomatic carriers (ASCs) or CHB receiving at least 8 years of anti-viral treatments was analyzed using Arraystar microarray and validated via quantitative real-time PCR (qRT-PCR). Correlation analysis was conducted based on correlation coefficients, Clusterprofile, and RNA Interactome Database (RAID). The functions of lncRNA in monocytes were determined via loss-of-function RNAi or gain-of-function lentivirus assays. The expression levels of mRNAs or proteins were evaluated using qRT-PCR, western blotting assay, or enzyme linked immunosorbent assays (ELISA).

Results

A total of 1,042 mRNA transcripts (630 up-regulated and 412 down-regulated) were identified being differentially expressed between ASC and CHB patients. Through enrichment analysis we focused on the transforming growth factor beta (TGF-β) signaling pathway and validated their expression in a larger cohort. Moreover, we found that lncRNA ENST00000519726 (lncRNA-HEIM) was highly expressed in monocytes and further up-regulated upon HBV infection. LncRNA-HEIM played an important role in CHB patients with long-term antiviral treatments, and its elevated expression was remarkably correlated with the TGF-β signaling pathway, especially with the two members namely TGF-β and SMAD4. Furthermore, altering the endogenous lncRNA-HEIM level in monocytes significantly affected the production of TGF-β, as well as the fibrosis of hepatic stellate cells by affecting the expression of collagen I and α-smooth muscle actin (α-SMA).

Conclusion

These findings not only added knowledge to the understanding of the roles of which lncRNA-HEIM played in the activation of HSCs in CHB patients with long-term medication, but also provided a promising therapeutic target in the future treatment for liver fibrosis.