As small conserved RNAs without a coding function, microRNAs are expressed in multicellular organisms and contribute to the modulation of multiple cellular reactions, such as viral replication, as well as autophagy. microRNAs can regulate host gene expression and inhibit or reinforce hepatitis B virus (HBV) replication. Hepatic cells express miR-155 noticeably. Consequently, our study explored miR-155 modulation of HBV replication and investigated the potential mechanism involved. miR-155 was inhibited on HBV infection. miR-155 transfection remarkably reinforced HBV replication, antigen expression, and progeny secretion in HepG2215 cells. Moreover, miR-155 impaired the inhibition of the cytokine signalling 1 (SOCS1)/Akt/ mTOR axis and reinforced HepG2215 autophagy. Additionally, the autophagy inhibitor (3-MA) eliminated HBsAg secretion triggered by miR-155. Taken together, miR-155 reinforced HBV replication by reinforcing SOCS1-triggered autophagy.Significance of the study: The research studied the potential mechanism involved in HBV replication and miR-155 that miR-155 reinforces HBV replication by reinforcing the SOCS1/Akt/mTOR axis-stimulated autophagy, and therefore, it can provide medical practitioners with the inspiration that chronic HBV might be cured or improved by regulating the activation of miR-155 in cells. In the study, the experiments show that autophagy inhibitors (3-MA) counteracted miR-155 contribution to HBV replication, and it might be a practicable way to improve HBV through some therapies that can repress the autophagy in related cells. K E Y W O R D S autophagy, HBV replication, infection, miR-155, SOCS1

Background/Aims: Zedoarondiol, a sesquiterpene lactone compound, showed an anti-proliferative activity on vascular smooth muscle cells in our previous study. However, whether it has a beneficial effect on endothelial cells injury induced by oxidized low-density lipoprotein (ox-LDL) remains unclear. This study was designed to investigate the protective effect of zedoarondiol on ox-LDL-induced injury of endothelial cells and explored its underlying mechanism. Methods: The protective effect of zedoarondiol on ox-LDL-induced human umbilical vein endothelial cells (HUVECs) injury were evaluated by Cell Counting Kit-8 (CCK-8) assay and released lactic dehydrogenase (LDH) activity assay. Oxidative stress was determined by malonedialdehyde (MDA) content and superoxide dismutase (SOD) activity. The level of reactive oxygen species (ROS) was measured by dichlorodihydrofluorescin diacetate (DCFH-DA) staining. The culture supernatant was collected for enzyme linked immune-sorbent assays (ELISA) of interleukine-1β (IL-1β), tumor necrosis factor-α (TNF-α), and monocyte chemoattractant protein-1 (MCP-1). Immunofluorescence staining was used to observe NF-E2-related factor 2 (Nrf2) translocation. Western blotting was performed to determine the expression of IL-1β, TNF-α, MCP-1, Kelch-like ECH associated protein 1 (Keap1), heme oxygenase-1 (HO-1), NAD(P)H: quinone oxidoreductase-1 (NQO1), and Nrf2. Results: Zedoarondiol attenuated HUVECs injury, up-regulated SOD activity, suppressed formation of MDA and ROS, and secretion and protein expression of IL-1β, TNF-α, and MCP-1 in injured HUVECs induced by ox-LDL. Zedoarondiol induced nuclear Nrf2 translocation from cytoplasm into nucleus and up-regulated expression of HO-1, NQO1, and Nrf2 in nucleus. All-trans-retinoic acid (ATRA), an inhibitor of Nrf2, abolished zedoarondiol-mediated anti-oxidative effect. Conclusion: Zedoarondiol attenuates ox-LDL-induced endothelial cells injury by inhibiting oxidative stress and inflammation via Nrf2/HO-1 pathway, suggesting that zedoarondiol might be meaningful on prevention and treatment of atherosclerosis.

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Background/Aims: Vascular smooth muscle cells (VSMCs) proliferation contributes significantly to atherosclerosis and in-stent restenosis. Platelet-derived growth factor-BB (PDGF-BB) plays a vital role in VSMCs proliferation. Zedoarondiol, a sesquiterpene lactone compound, has an anti-inflammatory activity. However, the role of zedoarondiol in PDGF-BB-mediated VSMCs proliferation remains unclear. In this study, we investigated the effects of zedoarondiol on PDGF-BB-induced VSMCs proliferation and explored the possible mechanisms. Methods: The inhibitory effects of zedoarondiol on PDGF-BB-induced VSMCs proliferation were evaluated by direct cell counting and the Cell Counting Kit-8 (CCK-8) assay. DNA synthesis was examined by bromodeoxyuridine (BrdU) incorporation assay. Cell cycle was assessed by propidium iodide staining. Western blotting was performed to determine the expression of cyclin-dependent kinase 2 (CDK2), cyclin E, p53, p21, total and phosphorylated adenosine monophosphate-activated protein kinase (AMPK), acetyl CoA carboxylase (ACC), mammalian target of rapamycin (mTOR), and p70 ribosomal protein S6 kinase (p70S6K). Results: Zedoarondiol suppressed PDGF-BB-induced VSMCs proliferation and DNA synthesis, and induced cell cycle arrest in G0/G1 phase. In addition, zedoarondiol activated AMPK and ACC, inhibited the phosphorylation of mTOR and p70S6K, increased the expression of p53 and p21, and decreased the expression of CDK2 and cyclin E. Compound C (an AMPK inhibitor) abrogated, whereas 5-aminoimidazole-4-carboxamide 1-β-ribofuranoside (AICAR, an AMPK activator) enhanced zedoarondiol-mediated inhibition of VSMCs proliferation and DNA synthesis. Conclusion: Zedoarondiol inhibits PDGF-BB-induced VSMCs proliferation via AMPK-mediated down-regulation of the mTOR/p70S6K pathway and up-regulation of the p53/p21 pathway. These findings suggest that zedoarondiol might be a promising compound against atherosclerosis and in-stent restenosis.

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