Transmembrane domain of IFITM3 is responsible for its interaction with influenza virus HA2 subunit.

Interferon-inducible transmembrane protein 3 (IFITM3) inhibits influenza virus infection by blocking viral membrane fusion, but the exact mechanism remains elusive. Here, we investigated the function and key region of IFITM3 in blocking influenza virus entry mediated by hemagglutinin (HA). The restriction of IFITM3 on HA-mediated viral entry was confirmed by pseudovirus harboring HA protein from H5 and H7 influenza viruses. Subcellular co-localization and immunocoprecipitation analyses revealed that IFITM3 partially co-located with the full-length HA protein and could directly interact with HA2 subunit but not HA1 subunit of H5 and H7 virus. Truncated analyses showed that the transmembrane domain of the IFITM3 and HA2 subunit might play an important role in their interaction. Finally, this interaction of IFITM3 was also verified with HA2 subunits from other subtypes of influenza A virus and influenza B virus. Overall, our data demonstrate for the first time a direct interaction between IFITM3 and influenza HA protein via the transmembrane domain, providing a new perspective for further exploring the biological significance of IFITM3 restriction on influenza virus infection or HA-mediated antagonism or escape.

Genus Lonicera: New drug discovery from traditional usage to modern chemical and pharmacological research.

BACKGROUND: Lonicera Linn. belonging to the family Caprifoliaceae, the largest genus in the plant family, includes about more than 200 species, which are mainly distributed in northern Africa, North America, Europe and Asia. Some species of this genus have been usually used in traditional Chinese medicine as well as functional foods, cosmetics and other applications, such as L. japonica Thunb. Bioactive components and pharmacological activities of the genus Lonicera plants have received an increasing interest from the scientific community. Thus, a comprehensive and systematic review on their traditional usage in China, chemical components, and their pharmacological properties of their whole plants, bioactive extracts, and bioactive isolates including partial structure-activity relationships from the genus is indispensable. METHODS: Information on genus Lonicera of this systematic electronic literature search was gathered via the published articles, patents, clinical trials website (https://clinicaltrials.gov/) and several online bibliographic databases (PubMed, Sci Finder, Research Gate, Science Direct, CNKI, Web of Science and Google Scholar). The following keywords were used for the online search: Lonicera, phytochemical composition, Lonicerae japonica, Lonicera review articles, bioactivities of Lonicera, anti-inflammatory, antiviral, antimicrobial, anticancer, hepatoprotective, antioxidant, neuroprotective, anti-diabetic, and clinical trials. This review paper consists of a total of 225 papers covering the Lonicera genus from 1800 to 2021, including research articles, reviews, patents, and book chapters. RESULTS: In this review (1800s-2021), about 420 components from the genus of Lonicera Linn. including 87 flavonoids, 222 terpenoids, 51 organic acids, and other compounds, together with their pharmacological activities including anti-inflammatory, antiviral, antimicrobial, anticancer, hepatoprotective, antioxidant, neuroprotective, antidiabetic, anti-allergic, immunomodulatory effects, and toxicity were summarized. CONCLUSION: The relationship is discussed among their traditional usage, their pharmacological properties, and their chemical components, which indicate the genus Lonicera have a large prospect in terms of new drug exploitation, especially in COVID-19 treatment.

The "LLQY" Motif on SARS-CoV-2 Spike Protein Affects S Incorporation into Virus Particles.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) glycoprotein mediates viral entry and membrane fusion. Its cleavage at S1/S2 and S2' sites during the biosynthesis in virus producer cells and viral entry are critical for viral infection and transmission. In contrast, the biological significance of the junction region between both cleavage sites for S protein synthesis and function is less understood. By analyzing the conservation and structure of S protein, we found that intrachain contacts formed by the conserved tyrosine (Y) residue 756 (Y756) with three α-helices contribute to the spike's conformational stability. When Y756 is mutated to an amino acid residue that can provide hydrogen bonds, S protein could be expressed as a cleaved form, but not vice versa. Also, the L753 mutation linked to the Y756 hydrogen bond prevents the S protein from being cleaved. Y756 and L753 mutations alter S protein subcellular localization. Importantly, Y756 and L753 mutations are demonstrated to reduce the infectivity of the SARS-CoV-2 pseudoviruses by interfering with the incorporation of S protein into pseudovirus particles and causing the pseudoviruses to lose their sensitivity to neutralizing antibodies. Furthermore, both mutations affect the assembly and production of SARS-CoV-2 virus-like particles in cell culture. Together, our findings reveal for the first time a critical role for the conserved L753-LQ-Y756 motif between S1/S2 and S2' cleavage sites in S protein synthesis and processing as well as virus assembly and infection. IMPORTANCE The continuous emergence of SARS-CoV-2 variants such as the delta or lambda lineage caused the continuation of the COVID-19 epidemic and challenged the effectiveness of the existing vaccines. Logically, the spike (S) protein mutation has attracted much concern. However, the key amino acids in S protein for its structure and function are still not very clear. In this study, we discovered for the first time that the conserved residues Y756 and L753 at the junction between the S1/S2 and S2' sites are very important, like the S2' cleavage site R815, for the synthesis and processing of S protein such as protease cleavage, and that the mutations severely interfered with the incorporation of S protein into pseudotyped virus particles and SARS-CoV-2 virus-like particles. Consequently, we delineate the novel potential target for the design of broad-spectrum antiviral drugs in the future, especially in the emergence of SARS-CoV-2 variants.

Generation and Evaluation of Recombinant Baculovirus Coexpressing GP5 and M Proteins of Porcine Reproductive and Respiratory Syndrome Virus Type 1.

Porcine reproductive and respiratory syndrome virus (PRRSV) is the pathogen of the porcine reproductive and respiratory syndrome, which is one of the most economically devastating diseases of the swine industry. However, whether the inactivated vaccine and modified live attenuated vaccines are effective in disease control is still controversial. Although several groups developed PRRSV virus-like particles (VLPs) as a vaccine against PRRSV, all these VLP-based vaccines targeted PRRSV-2, but not PRRSV-1 or both. Therefore, it is urgent to produce VLPs against PRRSV-1. In this study, we rescued recombinant baculovirus expressing GP5 and M proteins of PRRSV-1 through the Bac-to-Bac® baculovirus expression system. Thereafter, PRRSV VLP was obtained efficiently in the recombinant baculovirus-infected High Five insect cells. Moreover, the PRRSV VLP and PRRSV VLP+A5 could efficiently trigger specific humoral immune responses and B cellular immune responses through intranasal immunization. The combination of PRRSV VLP and A5 adjuvant could improve the level of the immune response. The PRRSV-1 VLPs generated in this study have greater potential for vaccine development to control PRRSV-1 infection.

MiR-122-5p knockdown protects against APAP-mediated liver injury through up-regulating NDRG3.

MiR-122-5p serves as a novel biomarker for drug-induced liver injury (DILI), but its function in DILI remains unclear. The present study, therefore, explored the function and potential mechanism of miR-122-5p in DILI. Sprague-Dawley (SD) rats were treated with miR-122-5p antagomir, and then DILI was induced in the rats by acetaminophen (APAP). To determine the effect of miR-122-5p on DILI in vivo, liver injury was examined by HE staining and TUNEL assays, and the levels of serum ALT and AST were determined using an automated clinical chemistry analyzer. To further reveal the mechanism of miR-122-5p in DILI, THLE-2 (normal liver cell line) cells were transfected with miR-122-5p mimic and inhibitor, NDRG3, and siNDRG3, and then injured by APAP. The relationship between miR-122-5p and NDRG3 was determined by TargetScan, luciferase reporter assay, and Western blot. The viability and apoptosis of THLE-2 cells were detected by CCK-8 and flow cytometry, respectively. The levels of mRNA and protein in vivo and in vitro were measured by qRT-PCR and Western blot, respectively. APAP induced liver injury and increased the levels of ALT, AST, and miR-122-5p in DILI rats. However, these effects of APAP were attenuated by miR-122-5p antagomir. MiR-122-5p negatively regulated NDRG3 expression. APAP decreased cell viability, apoptosis resistance, and Bcl-w and Bcl-2 levels whereas increased Bax level in THLE-2 cells. However, these effects of APAP on THLE-2 cells were promoted by miR-122-5p up-regulation but inhibited by miR-122-5p knockdown. MiR-122-5p knockdown protects against APAP-mediated liver injury through up-regulating NDRG3.

Current Progress on Host Antiviral Factor IFITMs.

Host antiviral factor interferon-induced transmembrane proteins (IFITMs) are a kind of small-molecule transmembrane proteins induced by interferon. Their broad-spectrum antiviral activity and unique ability to inhibit viral invasion have made them a hot molecule in antiviral research in recent years. Since the first demonstration of their natural ability to resist viral infection in 1996, IFITMs have been reported to limit a variety of viral infections, including some major pathogens that seriously endanger human health and social stability, such as influenza A, Ebol, severe acute respiratory syndrome, AIDS, and Zika viruses, etc. Studies show that IFITMs mainly exert antiviral activity during virus entry, specifically interfering with the fusion of the envelope and the endosome membrane or forming fusion micropores to block the virus from entering the cytoplasm. However, their specific mechanism is still unclear. This article mainly reviews the research progress in the structure, evolution, function, and mechanism of IFITMs, which may provide a theoretical basis for clarifying the molecular mechanism of interaction between the molecules and viruses and the research and development of new antiviral drugs based on IFITMs.

COVID-19 in China: From epidemiology to treatment (Review).

Coronavirus disease 2019 (COVID-19) is a newly emerging infectious disease caused by the novel coronavirus SARS-CoV-2. It first became prevalent in Wuhan, Hubei, China in December 2019. COVID-19 was initially characterized by pneumonia of unknown etiology, accompanied by fever, dry cough and fatigue. Due to its highly infectious nature it rapidly led to widespread human infection, causing 80,924 confirmed cases and 3,140 mortalities in mainland China as of March 9, 2020. The present review highlights the prevalence of COVID-19 in China, the etiology, pathology, clinical presentation, laboratory and chest imaging tests, and treatment of this disease.

Mesenchymal stem cell-based Smad7 gene therapy for experimental liver cirrhosis.

BACKGROUND: Bone mesenchymal stem cells (MSCs) can promote liver regeneration and inhibit inflammation and hepatic fibrosis. MSCs also can serve as a vehicle for gene therapy. Smad7 is an essential negative regulatory gene in the TGF-ß1/Smad signalling pathway. Activation of TGF-ß1/Smad signalling accelerates liver inflammation and fibrosis; we therefore hypothesized that MSCs overexpressing the Smad7 gene might be a new cell therapy approach for treating liver fibrosis via the inhibition of TGF-ß1/Smad signalling. METHODS: MSCs were isolated from 6-week-old Wistar rats and transduced with the Smad7 gene using a lentivirus vector. Liver cirrhosis was induced by subcutaneous injection of carbon tetrachloride (CCl4) for 8 weeks. The rats with established liver cirrhosis were treated with Smad7-MSCs by direct injection of cells into the main lobes of the liver. The expression of Smad7, Smad2/3 and fibrosis biomarkers or extracellular matrix proteins and histopathological change were assessed by quantitative PCR, ELISA and Western blotting and staining. RESULTS: The mRNA and protein level of Smad7 in the recipient liver and serum were increased after treating with Smad-MSCs for 7 and 21 days (P < 0.001). The serum levels of collagen I and III and collagenase I and III were significantly (P < 0.001) reduced after the treatment with Smad7-MSCs. The mRNA levels of TGF-ß1, TGFBR1, α-SMA, TIMP-1, laminin and hyaluronic acid were decreased (P < 0.001), while MMP-1 increased (P < 0.001). The liver fibrosis score and liver function were significantly alleviated after the cell therapy. CONCLUSIONS: The findings suggest that the MSC therapy with Smad7-MSCs is effective in the treatment of liver fibrosis in the CCl4-induced liver cirrhosis model. Inhibition of TGF-ß1 signalling pathway by enhancement of Smad-7 expression could be a feasible cell therapy approach to mitigate liver cirrhosis.

Si-Wei-Qing-Gan-Tang Improves Non-Alcoholic Steatohepatitis by Modulating the Nuclear Factor-κB Signal Pathway and Autophagy in Methionine and Choline Deficient Diet-Fed Rats.

Si-Wei-Qing-Gan-Tang (SWQGT) is a Chinese medicine formula that is widely used as a folk remedy of herbal tea for the treatment of chronic hepatitis, like non-alcoholic steatohepatitis (NASH), around Ganzhou City (Jiangxi province, China). However, the underlying mechanisms of this formula against NASH are still unknown. This study aimed to explore the effect and mechanisms of SWQGT against NASH. A network pharmacology approach was used to predict the potential mechanisms of SWQGT against NASH. Then a rat model of NASH established by feeding the methionine and choline deficient (MCD) diet was used to verify the effect and mechanisms of SWQGT on NASH in vivo. SWQGT (1 g/kg/d and 3 g/kg/d) were given by intragastric administration. Body weight, liver weight, serum biochemical indicators, liver triglyceride and total cholesterol were all measured. Tumor necrosis factor-α (TNF-α), Interleukin (IL)-1ß, IL-6 levels in the livers were evaluated using ELISA. Hematoxylin and eosin (HE) and Oil Red O staining were used to determine histology, while western blot was used to assess the relative expression levels of the nuclear factor-κB (NF-κB) pathway- and autophagy-related proteins. Functional and pathway enrichment analyses revealed that SWQGT obviously influenced inflammation-related signal pathways in NASH. Furthermore, in vivo experiment showed that SWQGT caused a reduction in liver weight and liver index of MCD diet-fed rats. The formula also helped to reduce hepatomegaly and improve pathological liver changes and hepatic steatosis. SWQGT likewise reduced liver TNF-α, IL-1ß, and IL-6 levels and down-regulated p-NF-κB p65, p-p38 MAPK, p-MEK1/2, p-ERK1/2, p-mTOR, and p62, while up-regulating p-ULK1 and LC3II protein expression levels. SWQGT could improve NASH in MCD diet-fed rats, and this effect may be associated with its down-regulation of NF-κB and activation of autophagy.

4,5-di-O-caffeoylquinic acid methyl ester isolated from Lonicera japonica Thunb. targets the Keap1/Nrf2 pathway to attenuate H2O2-induced liver oxidative damage in HepG2 cells.

BACKGROUND: 4,5-di-O-caffeoylquinic acid methyl ester (4,5-CQME) is a caffeoylquinic acid (CQA) isolated from Lonicera japonica Thunb., a traditional Chinese medicine. To date, the biological activity of 4,5-CQME has not been fully investigated. PURPOSE: The aim of the current study was to explore the anti-oxidative activity and the underlying mechanism of 4,5-CQME. METHODS: MTT assay was used to evaluate the cytoprotective effect of 4,5-CQME. DCFH-DA was used as a fluorescence probe to detect intracellular ROS. The mitochondrial membrane potential was detected using the fluorescent probe JC-1. MDA and GSH levels were measured using MDA and GSH commercial kits, respectively. Apoptosis assay was performed using the Annexin V-FITC/PI method. The functional mechanism of 4,5-CQME was investigated by analyzing relative signaling pathways through immunofluorescent staining, quantitative PCR and western blot analysis. RESULTS: HepG2 cells were incubated with different concentrations of 4,5-CQME for 12 h before exposure to 500 µM H2O2 for 3 h. 4,5-CQME attenuated H2O2-induced oxidative damage and had a higher cytoprotective effect than 3-caffeoylquinic acid, 3-caffeoylquinic acid methyl ester, or 4,5-di-O-caffeoylquinic acid. 4,5-CQME also reduced ROS and MDA levels and rescued GSH depletion. Western blots demonstrated that 4,5-CQME decreased Bax/Bcl-2 and Bak levels. A mechanistic study confirmed that 4,5-CQME significantly suppressed H2O2-induced MAPKs phosphorylation but had little effect on MAPKs phosphorylation under normal conditions. By contrast, 4,5-CQME induced AKT phosphorylation in the presence or absence of H2O2. 4,5-CQME also regulated the Keap1/Nrf2 signaling pathway and enhanced both the mRNA and protein expressions of HO-1 and NQO1. The anti-oxidative effect of 4,5-CQME was greatly abolished by co-incubation with the Nrf2 inhibitor ML385 or PI3K inhibitor wortmannin. CONCLUSIONS: Taken together, these results showed that 4,5-CQME offered significant protection against H2O2-induced oxidative stress, and its effect was in part due to the modulation of the Keap1/Nrf2 pathway.

Construction, expression and antiviral activity analysis of recombinant adenovirus expressing human IFITM3 in vitro.

Interferon-inducible transmembrane protein 3 (IFITM3) inhibits the replication of multiple pathogenic viruses by blocking their entry. In this study, we constructed a shuttle plasmid, harboring human IFITM3. Thereafter, recombinant adenovirus rAd5-IFITM3 was obtained by co-transfection of the linearized viral backbone vector pAd5 and the shuttle plasmid. The results showed that human IFITM3 did not affect the assembly and morphogenesis of progeny adenovirus. Human IFITM3 can be expressed in both A549 and MDCK cells in a time dependent manner. Furthermore, cells infected with rAd5-IFITM3 at a multiplicity of infection (MOI) of 100 for 24 h were challenged with avian influenza virus (AIV) H5N1 at an MOI of 1 for 6, 12 and 24 h. Rates of H5N1 infection in rAd5-IFITM3 cells were significantly decreased at 24 h post-infection (hpi), in a time dependent manner, compared with that of wild type wtAd5-infected cells. The expressions of viral genes were significantly inhibited at transcriptional and translational levels at 6 and 12 hpi. These results suggest that IFITM3 can suppress H5N1 replication in the early stage of the infection, which may be used as a promise agent against H5N1 infection in vivo.

Differential Activation of NLRP3, AIM2, and IFI16 Inflammasomes in Humans with Acute and Chronic Hepatitis B.

Nod-like receptor protein 3 (NLRP3), absent in melanoma 2 (AIM2), and interferon gamma inducible protein 16 (IFI16) are innate immune sensors for intracellular microbes, which can be activated by various dangerous signals and subsequently lead to caspase-1 (CASP1) activation and the maturation cleavage of effector molecules pro-IL-1ß and pro-IL-18. Their roles in immunopathology of acute and chronic hepatitis B virus (HBV) infection are still unclear. In this study, we first investigated the activation of NLRP3, AIM2, and IFI16 inflammasomes in peripheral blood mononuclear cells (PBMCs) from patients infected with acute hepatitis B (AHB) and chronic hepatitis B (CHB) by quantitative real-time PCR and enzyme-linked immunosorbent assay. We next analyzed the impact of hepatitis B e antigen (HBeAg) on activation of AIM2 and IFI16 inflammasomes in PBMCs of CHB patients stimulated in vitro with AIM2 and IFI16 agonist ligands, poly (dA:dT) and VACA-70mer, respectively. The results showed that the mRNA expression levels of AIM2, IFI16, and CASP1 in PBMCs from AHB and CHB patients were both upregulated. Furthermore, the mRNA levels of AIM2 and IFI16 in CHB patients were significantly positively correlated with serum HBV loads. However, only in patients with AHB there was elevation of serum IL-1ß and IL-18. There was no activation of NLRP3, AIM2, and IFI16 inflammasomes in CHB patients. Stimulation of PBMCs of CHB patients in vitro with poly (dA:dT) and VACA-70mer induced the activation of AIM2 and IFI16 inflammasomes, respectively. This ligand-induced activation was suppressed by HBeAg. Our results suggest that there exists activation of the AIM2 and IFI16 inflammasomes, but not the NLRP3 inflammasome, in AHB, and the activation of the AIM2 and IFI16 inflammasomes can be inhibited by HBeAg in CHB, which may contribute to HBV-induced immunotolerance.

The Host Restriction Factor Interferon-Inducible Transmembrane Protein 3 Inhibits Vaccinia Virus Infection.

Interferons (IFNs) establish dynamic host defense mechanisms by inducing various IFN-stimulated genes that encodes many antiviral innate immune effectors. IFN-inducible transmembrane (IFITM) proteins have been identified as intrinsic antiviral effectors, which block the entry of a broad spectrum of enveloped RNA viruses by interrupting virus-endosomal fusion. However, antiviral activity of IFITM proteins against mammalian DNA virus has not been demonstrated till date. Here, we sought to investigate the antiviral activities and mechanisms of interferon-inducible transmembrane protein 3 (IFITM3) protein against poxvirus infection. Analysis of expression kinetics of cell endogenous IFITM3 protein indicated that vaccinia virus (VACV) infection suppressed its translation, which was independent of IRF3 phosphorylation triggered by VACV. Although silencing of endogenous IFITM proteins did not affect their baseline antiviral effects in the cell, it has reduced the IFN-α-mediated inhibition of VACV infection, and also modulated VACV-induced cell death. Moreover, we discovered that overexpression of IFITM3 significantly restricted VACV infection, replication and proliferation mainly by interfering with virus entry processes prior to the virus nucleocapsid entry into the cytoplasm. Interestingly, IFITM3 overexpression showed an impact on virus binding. Furthermore, IFITM3 interfered with the cytosolic entry of virus through low pH-dependent fashion. Taken together, our findings provide the first evidence of exogenously expressed IFITM3 protein restricting infection of an enveloped DNA virus, thus expanding their antiviral spectrum. This study further explores the complex mechanism and provides novel insights into the interaction between virus infection and host defense.

Lepidium meyenii Walp Exhibits Anti-Inflammatory Activity against ConA-Induced Acute Hepatitis.

Strong inflammation is a prominent pathogenesis of acute hepatitis, which can induce hepatocyte death and lead to liver failure. Lepidium meyenii Walp (Maca) is a traditional herbal medicine mostly used in improving sperm motility and serum hormone levels, etc. However, there are no reports that showed Maca was designed for treating hepatitis so far. Therefore, the protective effects and pharmacological mechanisms of Maca are unknown in hepatitis. In this study, we found that the protective effects of Maca extract ameliorate ConA-induced acute hepatitis (CIH) and underlying mechanisms. We determined that pretreatment with Maca extract significantly suppressed the production of aminotransferases and inflammatory cytokines, including IFN-γ, TNF-α, IL-1ß, IL-2, IL-6, IL-12, and IL-17a, and moderated acute liver injury in CIH. Maca recruited more myeloid-derived suppressor cells (MDSCs) to the liver and suppressed infiltration of natural killer T cells (NKT cells) and macrophages in the liver. Furthermore, our data indicated the molecular mechanism of the inhibitory inflammatory effects of Maca, which should suppress the activation of NF-κB, IFN-γ/STAT1, and IL-6/STAT3 signalings. Collectively, this present research explores Maca as an effective hepatoprotective medicine to inhibit inflammation and liver injury caused by acute hepatitis.

Smad7-overexpressing rat BMSCs inhibit the fibrosis of hepatic stellate cells by regulating the TGF-ß1/Smad signaling pathway.

Mesenchymal stem cells (MSCs) are able to differentiate into hepatocytes, promote the regeneration of hepatic cells and inhibit the progression of hepatic fibrosis. Transforming growth factor (TGF)-ß1 is one of the key factors in the development of liver fibrosis, which also promotes extracellular matrix (ECM) formation. Drosophila mothers against decapentaplegic 7 (Smad7) is an essential negative regulator in the TGF-ß1/Smad signaling pathway. In the present study, bone mesenchymal stem cells (BMSCs) were isolated from rat bone marrow and transfected with lentiviral vectors carrying the Smad7 gene. Smad7-enhanced green fluorescent protein (EGFP)-BMSCs stably expressing Smad7 were subsequently co-cultured with hepatic stellate cells (HSCs) for 48 h. Smad7 and TGF-ß1 levels in the culture medium were detected using ELISA, and the levels of collagen (Col) I, Col III, laminin (LN) and hyaluronic acid (HA) were measured using immunoassays. The early apoptosis rates of HSCs were determined via flow cytometry. Reverse transcription-quantitative polymerase chain reaction and western blotting were performed to evaluate the mRNA and protein expression profiles, respectively. The results indicated that Smad7-EGFP-BMSCs stably expressing Smad7 were successfully constructed. Upon co-culturing with rat Smad7-EGFP-BMSCs, the early apoptotic rate of HSCs was significantly increased (P<0.05). Levels of Smad7 in the culture medium were also significantly increased (P<0.05), whereas the levels of TGF-ß1, Col I, Col III, LN and HA were significantly decreased (P<0.05). Furthermore, the mRNA and protein levels of Smad7 and matrix metalloproteinase 1 were significantly increased (P<0.05), whereas those of TGF-ß1, α-SMA, Smad2, smad3, TGF-ß receptor I, Col I, tissue inhibitors of metalloproteinase-1 and Col III were significantly decreased. The results of the present study suggest that rat BMSCs overexpressing Smad7 may inhibit the fibrosis of HSCs by regulating the TGF-ß1/Smad signaling pathway. This provides a novel insight into future treatments for liver fibrosis.

HOTAIR, a long non-coding RNA driver of malignancy whose expression is activated by FOXC1, negatively regulates miRNA-1 in hepatocellular carcinoma.

Evidence is rapidly accumulating that long non-coding RNAs (lncRNAs) are involved in human tumorigenesis and are dysregulated in multiple cancers, including hepatocellular carcinoma (HCC). lncRNAs can regulate essential pathways that contribute to tumor initiation and progression with tissue specificity, which suggests that lncRNAs may be valuable biomarkers and therapeutic targets. HOX transcript antisense intergenic RNA (HOTAIR) has previously been demonstrated to be an oncogene and a negative prognostic factor in a variety of cancers; however, the factors that contribute to the upregulation of HOTAIR and the interaction between HOTAIR and microRNAs (miRNAs or miRs) are largely unknown. In the present study, the expression levels of HOTAIR, forkhead box C1 (FOXC1) and miRNA-1 were examined in 50 matched pairs of HCC and HCC cells. The effects of HOTAIR on HCC cell proliferation were tested using trypan blue exclusion assay. The effect of HOTAIR on HCC growth in vivo was determined in a (nu/nu) mouse model. A computational screening of HOTAIR promoter was conducted to search for transcription factor-binding sites. FOXC1 binding to the promoter region of HOTAIR was confirmed using a chromatin immunoprecipitation assay. A search for miRNAs that had complementary base paring with HOTAIR was performed utilizing an online software program. The interaction between miR-1 and HOTAIR was examined using a luciferase reporter assay. Gain and loss of function approaches were used to determine the changes of HOTAIR or miR-1 expression. The relative levels of FOXC1 and HOTAIR expression in HCC tissues and HepG2 cells were significantly higher than those in normal liver LO2 cells and adjacent carcinoma tissues; the relative expression of miR-1 exhibited the opposite pattern. Overexpression of HOTAIR promoted HCC cell proliferation and progression of tumor xenografts. The present authors have demonstrated that FOXC1 binds to the upstream region of HOTAIR in HCC cells and that FOXC1 activates lncRNA HOTAIR expression in HCC HepG2 cells, which suggests that HOTAIR harbors a miRNA-1 binding site. The present data revealed that this binding site is vital for the regulation of miRNA-1 by HOTAIR. Furthermore, HOTAIR negatively regulated the expression of miRNA-1 in HepG2 cells. Additionally, the present study demonstrated that the oncogenic activity of HOTAIR is in part based on the negative regulation of miR-1. Taken together, these results suggest that HOTAIR is a FOXC1-activated driver of malignancy, which acts in part through the repression of miR-1.

[Clinical characteristics and molecular epidemiology of carbapenem- resistant Acinetobacter baumannii infections at Shenzhen People's Hospital during an 8-year period].

OBJECTIVE: To investigate the clinical features, mechanism of resistance and molecular epidemiology of carbapenem-resistant Acinetobacter baumannii (CRAB) infections at Shenzhen People's Hospital during an 8-year period. METHODS: A. baumannii isolates were recovered from nosocomial infections patients at this hospital from 2002 to 2009. The minimum inhibitory concentrations (MICs) of antimicrobial agents against A. baumannii isolates were detected by agar dilution method. Polymerase chain reaction (PCR) and DNA sequencing were used to examine the carbapenemase genotype among CRAB. All isolates were typed by pulse field gel electrophoresis (PFGE). Clinical cases of CRAB infections were retrospectively analyzed according to Chinese experts' consensus on diagnosis, treatments, preventions and controls of Acinetobacter baumannii infections in China. RESULTS: A total of 87 cases of CRAB nosocomial infections were diagnosed in this study. The most prominent infections caused by CRAB was lung infections, followed by bloodstream infections, wound infections and abdominal infections, accounting for 69.0%, 8.0%, 8.0% and 6.9% of 87 cases, respectively. Approximately 80.5% (70/87) of CRAB isolated from intensive care unit (ICU). A sharp increase of CRAB infections (42/87) occurred in 2009, with the majority of pulmonary infections (34/42). Genotyping by PFGE found eight distinct PFGE patterns among 87 isolates of CRAB. The prominent CRAB clone A, carrying a blaOXA-58-like carbapenemase gene, had been prevalent from 2002 to 2006 at this hospital. The CRAB clone C, harboring a blaOXA-23-like carbapenemase gene, as well as clone A became the prominent clones during 2007 to 2008. The CRAB clone D, carrying a blaOXA-23-like carbapenemase gene, replaced clone A and C, and became the dominant clone in 2009. CONCLUSION: The spread of the CRAB clone D harboring a blaOXA-23-like gene causes a rapid increase of CRAB infections at this hospital during 2009.

[Effects comparison of lamivudine therapy for hepatitis B virus genotypes B and C].

OBJECTIVE: To determine the lamivudine response of HBV genotypes in patients with HBV DNA positive chronic hepatitis. METHODS: Clinical data from 235 patients in the original trial were analyzed. RESULTS: 135 patients received lamivudine and 100 patients as controls. Almost all patients had HBV genotypes B or C. Antiviral response were 92.9% and 75.9% in lamivudine-treated patients (chi-square = 6.628, P < 0.05) and 9.8% and 8.5% in untreated controls (P > 0.05) with HBV genotype B and C, respectively. The incidences of lamivudine-induced mutation in YMDD motif were 3.6% and 16.5% in HBV genotype B and C, respectively (chi-square = 5.508, P < 0.01). We identified HBV genotype B, elevated pretreatment alanine aminotransferase (ALT) levels, and low pretreatment HBV DNA levels as independent factors associated with antiviral response. CONCLUSION: HBV genotype B was associated with a higher rate of lamivudine-induced HBV DNA clearance and lower rate of lamivudine-induced YMDD mutation compared with genotype C. HBV genotypes may be an important determinant of lamivudine therapy of chronic hepatitis B.