Hepatitis B Virus Induces Autophagy to Promote its Replication by the Axis of miR-192-3p-XIAP Through NF kappa B Signaling.

Hepatitis B virus (HBV) is a major risk factor for the development and progression of hepatocellular carcinoma. It has been reported that viral infection can interfere with cellular microRNA (miRNA) expression and participate in the pathogenesis of oncogenicity. Here, we report that decreasing levels of the expression of the miRNA miR-192-3p is associated with rising levels of HBV DNA in the serum of HBV patients. We revealed that HBV infection repressed the expression of miR-192-3p through hepatitis B x protein interaction with c-myc. We further showed that miR-192-3p was repressed by HBV transfection in vitro and in a mouse model, leading to cellular autophagy. Using an miRNA target prediction database miRBase, we identified X-linked inhibitor of apoptosis protein (XIAP) as a target gene of miR-192-3p and demonstrated that miR-192-3p directly targeted the XIAP 3'-untranslated region of XIAP messenger RNA. Importantly, we discovered that HBV promoted autophagy through miR-192-3p-XIAP axis and that this process was important for HBV replication in vitro and in vivo. We demonstrated that miR-192-3p functioned through the nuclear factor kappa B signaling pathway to inhibit autophagy, thereby reducing HBV replication. Conclusions: Our findings indicate that miR-192-3p is a regulator of HBV infection and may play a potential role in hepatocellular carcinoma. It may also serve as a biomarker or therapeutic target for HBV patients.

Salidroside alleviates diet-induced obesity and insulin resistance by activating Nrf2/ARE pathway and enhancing the thermogenesis of adipose tissues.

Recent reports suggest that salidroside protects cardiomyocytes from oxidative injury and stimulates glucose uptake by skeletal muscle cells. Despite these findings, the therapeutic potential of salidroside in the treatment of obesity and insulin resistance remains uncertain and requires further investigation. In the present study, the treatment effect of salidroside on the onset and development of the obese phenotype and insulin resistance as well as the underlying mechanisms was investigated using long-term high-fat diet-induced obese mice supplemented with salidroside. We used biochemical kits to determine serum biochemical parameters (including triacylglycerol, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, fasting glucose, and insulin). The results show that salidroside-supplemented animals showed better glucose tolerance and insulin sensitivity, decreased blood lipids, and weight gain (p < .05). Protein expression of p-Nrf2 and Nrf2 was analyzed by western blotting, and the mRNA levels of thermogenic-related genes (Ucp1, Pgc1a, Prdm16, and Cidea) were detected by quantitative RT-PCR. The results show an improvement in lipid peroxidation and Nrf2/ARE signaling, as well as an increased expression of the Ucp1, Pgc1a, Prdm16, and Cidea (p < .05). Our evidence suggests that salidroside alleviates diet-induced obesity and insulin resistance potentially by activating Nrf2/ARE pathway and enhancing the thermogenesis of adipose tissues. This induction represents a potential technique for the management of comorbidities related to obesity and its prevention.

Upregulation of miR-520c-3p via hepatitis B virus drives hepatocellular migration and invasion by the PTEN/AKT/NF-κB axis.

Hepatitis B virus (HBV) is a major risk factor for the development and progression of hepatocellular carcinoma (HCC). It has been reported that viral infection can interfere with the expression of cellular microRNA (miRNA) to affect oncogenesis. In this study, we showed that miR-520c-3p was upregulated in liver tumor specimens, and we revealed that HBV infection enhanced the expression of miR-520c-3p through the interaction of viral protein HBV X protein (HBx) with transcription factor CREB1. We further showed that miR-520c-3p induced by HBV transfection/infection caused epithelial-mesenchymal transition (EMT). Using the miRNA target prediction database miRBase and luciferase reporter assays, we identified PTEN as a novel target gene of miR-520c-3p and miR-520c-3p directly targeted PTEN's 3'-untranslated region. Moreover, we discovered that HBV promoted EMT via the miR-520c-3p-PTEN to activate AKT-NFκB signaling pathway, leading to increased HCC migration and invasion. Importantly, miR-520c-3p antagomir significantly represses invasiveness in HBx-induced hepatocellular xenograft models. Our findings indicate that miR-520c-3p is a novel regulator of HBV and plays an important role in HCC progression. It may serve as a new biomarker and molecular therapeutic target for HBV patients.

Hepatitis B virus promotes cancer cell migration by downregulating miR-340-5p expression to induce STAT3 overexpression.

BACKGROUND: Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide, and infection with hepatitis B virus (HBV) is a leading cause of HCC. Previous studies have demonstrated that expression of the tumor inhibitor miR-340 is significantly downregulated in HCC tissues compared with normal liver tissues. However, the precise biological role of miR-340-5p in HBV-HCC and its molecular mechanism of action remain unknown. RESULTS: Expression of miR-340-5p was downregulated in HBV-associated HCC liver tissue and HBV-infected cells, facilitating migration of liver cancer cells. Signal transducer and activator of transcription (STAT)3 was found to be a direct functional target of miR-340-5p. The regulation of STAT3 expression by miR-340-5p was assessed using qRT-PCR and western blotting, and the effects of exogenous miR-340-5p and STAT3 on the migration of HBV-infected cells were evaluated in vitro using Transwell® and wound-healing assays. The expression of E-cadherin and vimentin, associated with epithelial-mesenchymal transition, was also assessed using Western blotting after transfection of miR-340-5p mimics and/or STAT3 expression vectors. Overexpression of STAT3 resulted in rescue of HBV effects, decreased E-cadherin expression, increased vimentin expression, and ultimately, enhanced cell migration. Re-introduction of the STAT3 CDS led to marked reversal of the inhibition of cell migration in HBV-infected cells mediated by miR-340-5p. CONCLUSIONS: Hepatitis B virus promotes the migration of liver cancer cells by downregulating miR-340-5p expression to induce STAT3 overexpression. Our results show that STAT3 plays a key role in regulating cell migration in HBV-HCC involving miR-340-5p.

Bivalent Copper Ions Promote Fibrillar Aggregation of KCTD1 and Induce Cytotoxicity.

Potassium channel tetramerization domain containing 1 (KCTD1) family members have a BTB/POZ domain, which can facilitate protein-protein interactions involved in the regulation of different signaling pathways. KCTD proteins have potential Zn(2+)/Cu(2+) binding sites with currently unknown structural and functional roles. We investigated potential Cu(2+)-specific effects on KCTD1 using circular dichroism, turbidity measurement, fluorescent dye binding, proteinase K (PK) digestion, cell proliferation and apoptosis assays. These experiments indicate that the KCTD1 secondary structure assumes greater ß-sheet content and the proteins aggregate into a PK-resistant form under 20 µM Cu(2+), and this ß-sheet-rich aggregation with Cu(2+) promotes fibril formation, which results in increased cell toxicity by apoptosis. Our results reveal a novel role for Cu(2+) in determining the structure and function of KCTD1.