Antagonizing apolipoprotein J chaperone promotes proteasomal degradation of mTOR and relieves hepatic lipid deposition.

BACKGROUND AND AIMS: Overnutrition-induced activation of mammalian target of rapamycin (mTOR) dysregulates intracellular lipid metabolism and contributes to hepatic lipid deposition. Apolipoprotein J (ApoJ) is a molecular chaperone and participates in pathogen-induced and nutrient-induced lipid accumulation. This study investigates the mechanism of ApoJ-regulated ubiquitin-proteasomal degradation of mTOR, and a proof-of-concept ApoJ antagonist peptide is proposed to relieve hepatic steatosis. APPROACH AND RESULTS: By using omics approaches, upregulation of ApoJ was found in high-fat medium-fed hepatocytes and livers of patients with NAFLD. Hepatic ApoJ level associated with the levels of mTOR and protein markers of autophagy and correlated positively with lipid contents in the liver of mice. Functionally, nonsecreted intracellular ApoJ bound to mTOR kinase domain and prevented mTOR ubiquitination by interfering FBW7 ubiquitin ligase interaction through its R324 residue. In vitro and in vivo gain-of-function or loss-of-function analysis further demonstrated that targeting ApoJ promotes proteasomal degradation of mTOR, restores lipophagy and lysosomal activity, thus prevents hepatic lipid deposition. Moreover, an antagonist peptide with a dissociation constant (Kd) of 2.54 µM interacted with stress-induced ApoJ and improved hepatic pathology, serum lipid and glucose homeostasis, and insulin sensitivity in mice with NAFLD or type II diabetes mellitus. CONCLUSIONS: ApoJ antagonist peptide might be a potential therapeutic against lipid-associated metabolic disorders through restoring mTOR and FBW7 interaction and facilitating ubiquitin-proteasomal degradation of mTOR.

Reversibility of some oxidative stress markers in chronic hepatitis C patients after receiving direct-acting antiviral agents.

Introduction: Hepatitis C (HCV) is associated with extra-hepatic involvment, morbidity as well as metabolic changes. Whether these might be reversible if sustained virologic response (SVR) is achieved by direct-acting antiviral (DAA) therapy remains unknown. Methods: Chronic hepatitis C (CHC) individuals receiving DAA treatment with SVR were compared to those who underwent spontaneous clearance (SC) of HCV infection at the 2-year follow-up. Plasma oxidative stress markers (oxidized low-density lipoprotein (oxLDL), 8-hydroxy-2'-deoxyguanosine (8-OHdG), malondialdehyde (MDA) and ischemia-modified albumin (IMA)) as well as progression of liver fibrosis were evaluated. Results: Compared to SC individuals, those in the CHC group exhibited at baseline higher levels of oxLDL, 8-OHdG and IMA but not of MDA. In the SC group, 8-OHdG levels were elevated at 2-year post-SVR (p = 0.0409), while the DAA-treated CHC group showed decrease in oxLDL (p < 0.0001) and 8-OHdG (p = 0.0255) levels, approaching those of the SC group, but increased MDA (p = 0.0055) levels. Additionally, oxLDL levels were positively correlated with liver stiffness measurements at SVR (p = 0.017) and at 1 year post- SVR (p = 0.002). Conclusions: Plasma oxLDL showed post-SVR normalization after clearance of HCV viremia with DAAs and was associated with levels of hepatic fibrosis.

Establishment of quantitative and recovery method for detection of dengue virus in wastewater with noncognate spike control.

Wastewater-based epidemiology (WBE) represents an efficient approach for public pathogen surveillance as it provides early warning of disease outbreaks; however, it has not yet been applied to dengue virus (DENV), which might cause endemics via mosquito spread. In this study, a working platform was established to provide direct virus recovery and qPCR quantification from wastewater samples that were artificially loaded with target DENV serotypes I to IV and noncognate spike control viral particles. The results showed qPCR efficiencies of 91.2 %, 94.8 %, 92.6 % and 88.7 % for DENV I, II, III, and IV, respectively, and a broad working range over 6 orders of magnitude using the preferred primer sets. Next, the results revealed that the ultrafiltration method was superior to the skimmed milk flocculation method for recovering either DENV or control viral particles from wastewater. Finally, DENV-2 was loaded simultaneously with the noncognate spike control and could be recovered at comparable levels either in PBS or in wastewater, indicating the applicability of noncognate spike control particles to reflect the efficiency of experimental steps. In conclusion, our data suggest that DENV particles in wastewater could be recovered and quantitatively detected in absolute amounts, indicating the feasibility of DENV surveillance using the WBE approach.

Interdependence of glycemic and lipid modulation in cured chronic hepatitis C patients by direct-acting antiviral agents.

BACKGROUND: Chronic hepatitis C virus (HCV) infection causes various liver diseases and metabolic disorders. With direct-acting antiviral agents (DAAs), which effectively eradicate pan-genotypic HCV, hepatic and concomitant metabolic restorations are achieved. The study aims to evaluate the posttherapeutic benefits of lipid and glycemic homeostasis. METHODS: Nighty-five chronic hepatitis C patients who achieved sustained virological response (SVR) by using DAAs were enrolled to collect plasma samples and fractionated lipoproteins at baseline, SVR, and during the post-SVR follow-ups for 6 months (pS6m) and 1 year (pS1yr). The lipid and glycemic parameters were analyzed to establish muturally modulatory relationships. RESULTS: Plasma cholesterol (Chol) and glucose were elevated at SVR from baseline, whereas plasma Chol remained increased until pS1yr; however, glucose returned to the basal level. The post-SVR responses included a peak elevation of glycated hemoglobin at pS6m, a sustained elevation of triglyceride (Tg), and sustained declines in insulin, homeostasis model assessment (HOMA)-insulin resistance, and HOMA-beta levels until pS1yr. The changes in plasma Chol and high-density-lipoprotein Chol showed positive correlations, as did the plasma Tg with low-density-lipoprotein Tg and very-low-density-lipoprotein Tg per particle load. Very-low-density-lipoprotein was found to be loaded with increased Tg and Chol and underwent efficient Tg catabolism in the form of conversion into low-density-lipoprotein. Additionally, the posttherapeutic dynamics exhibited correlations of high-density-lipoprotein Chol with plasma glucose and HOMA-beta. CONCLUSION: Irrespective of the baseline metabolic status, the posttherapeutic interdependent modulation of blood glycemic and lipid metabolic parameters were revealed in chronic hepatitis C patients following clearance of HCV viremia by DAA treatment.

Using a 3D Silicon Micro-Channel Device and Raman Spectroscopy for the Analysis of Whole Blood and Abnormal Blood.

Blood testing is a crucial application in the field of clinical studies for disease diagnosis and screening, biomarker discovery, organ function assessment, and the personalization of medication. Therefore, it is of the utmost importance to collect precise data in a short time. In this study, we utilized Raman spectroscopy to analyze blood samples for the extraction of comprehensive biological information, including the primary components and compositions present in the blood. Short-wavelength (532 nm green light) Raman scattering spectroscopy was applied for the analysis of the blood samples, plasma, and serum for detection of the biological characteristics in each sample type. Our results indicated that the whole blood had a high hemoglobin content, which suggests that hemoglobin is a major component of blood. The characteristic Raman peaks of hemoglobin were observed at 690, 989, 1015, 1182, 1233, 1315, and 1562-1649 cm-1. Analysis of the plasma and serum samples indicated the presence of ß-carotene, which exhibited characteristic peaks at 1013, 1172, and 1526 cm-1. This novel 3D silicon micro-channel device technology holds immense potential in the field of medical blood testing. It can serve as the basis for the detection of various diseases and biomarkers, providing real-time data to help medical professionals and patients better understand their health conditions. Changes in biological data collected in this manner could potentially be used for clinical diagnosis.

Assessment of ELISA-based method for the routine examination of serum indoxyl sulfate in patients with chronic kidney disease.

Introduction: Indoxyl sulfate (IS), a protein-bound uremic toxin, is associated with kidney function and chronic kidney disease (CKD)-related complications. Currently, serum IS levels are primarily quantified using mass spectrometry-based methods, which are not feasible for routine clinical examinations. Methods: The efficiencies of three commercial ELISA kits in determination of serum IS were validated by comparing with ultra-performance liquid chromatography (UPLC)-MS/MS-based method using Bland-Altman analysis. The associations between kidney parameters and serum IS levels determined by ELISA kit from Leadgene and UPLC-MS/MS were evaluated by Spearman correlation coefficient in a CKD validation cohort. Results: ELISA kit from Leadgene showed clinical agreement with UPLC-MS/MS in the determination of serum IS levels (p = 0.084). In patients with CKD, Spearman's correlation analysis revealed a perfect correlation between the IS levels determined using the Leadgene ELISA kit and UPLC-MS/MS (r = 0.964, p < 0.0001). IS levels determined using the Leadgene ELISA kit were associated with the estimated glomerular filtration rate (r = -0.772, p < 0.0001) and serum creatinine concentration (r = 0.824, p < 0.0001) in patients with CKD, and on dialysis (r = 0.557, p = 0.006). Conclusions: The Leadgene ELISA kit exhibits comparable efficacy to UPLC-MS/MS in quantifying serum IS levels, supporting that ELISA would be a personalized method for monitoring the dynamic changes in serum IS levels in dialysis patients to prevent the progression of CKD.

Sterol O-acyltransferase 2 chaperoned by apolipoprotein J facilitates hepatic lipid accumulation following viral and nutrient stresses.

The risks of non-alcoholic fatty liver disease (NAFLD) include obese and non-obese stresses such as chronic hepatitis C virus (HCV) infection, but the regulatory determinants remain obscure. Apolipoprotein J (ApoJ) served as an ER-Golgi contact-site chaperone near lipid droplet (LD), facilitating HCV virion production. We hypothesized an interplay between hepatic ApoJ, cholesterol esterification and lipid deposit in response to NAFLD inducers. Exposures of HCV or free-fatty acids exhibited excess LDs along with increased ApoJ expression, whereas ApoJ silencing alleviated hepatic lipid accumulation. Both stresses could concomitantly disperse Golgi, induce closer ApoJ and sterol O-acyltransferase 2 (SOAT2) contacts via the N-terminal intrinsically disordered regions, and increase cholesteryl-ester. Furthermore, serum ApoJ correlated positively with cholesterol and low-density lipoprotein levels in normal glycaemic HCV patients, NAFLD patients and in mice with steatosis. Taken together, hepatic ApoJ might activate SOAT2 to supply cholesteryl-ester for lipid loads, thus providing a therapeutic target of stress-induced steatosis.

Differential dynamics of hepatic protein expressions with long-term cultivated hepatitis C virus infection.

BACKGROUND: The liver maintains blood chemical homeostasis by active uptake and secretion through endocytosis, exocytosis, and intracellular trafficking between the plasma and intracellular membranes. Hepatitis C virus (HCV) infection affects the host membrane architecture and might thus impair the regulation of the cellular transportation machinery. Additionally, the hepatic expressions of differential protein dynamics with long-term HCV infection remain fully recover. METHODS: In this study, comparative proteomic analysis was performed in HCV-infected and mock-control Huh7 cells according to the viral dynamics of exponential, plateau, declined, and silencing phases at the acute stage, and the chronic stage. The proteins with <0.8-fold and ≥1.25-fold changes in expression were analyzed using functional pathway clustering prediction. RESULTS: The combined experimental repetitions identified full-spectrum cellular proteins in each of 5 sample sets from acute exponential, plateau, declined, and silencing phases, and the chronic stage. The clustering results revealed that HCV infection might differentiate regulatory pathways involving extracellular exosome, cadherin, melanosome, and RNA binding. Overall host proteins in HCV-infected cells exhibited kinetic pattern 1, in which cellular expression was downregulated from the acute exponential to plateau phases, reached a nadir, and was then elevated at the chronic stage. The proteins involved in the membrane-budding pathway exhibited kinetic pattern 2, in which their expressions were distinctly downregulated at the chronic stage. CONCLUSION: The current comparative proteomics revealed the differential regulatory effects of HCV infection on host intracellular transport functional pathways, which might contribute to the pathogenic mechanisms of HCV in hepatocytes that sustain long-term infection.

Plasma proteome plus site-specific N-glycoprofiling for hepatobiliary carcinomas.

Hepatobiliary cancer is the third leading cause of cancer death worldwide. Appropriate markers for early diagnosis, monitoring of disease progression, and prediction of postsurgical outcome are still lacking. As the majority of circulating N-glycoproteins are originated from the hepatobiliary system, we sought to explore new markers by assessing the dynamics of N-glycoproteome in plasma samples from patients with hepatocellular carcinoma (HCC), cholangiocarcinoma (CCA), or combined HCC and CCA (cHCC-CCA). Using a mass spectrometry-based quantitative proteomic approach, we found that 57 of 5358 identified plasma proteins were differentially expressed in hepatobiliary cancers. The levels of four essential proteins, including complement C3 and apolipoprotein C-III in HCC, galectin-3-binding protein in CCA, and 72 kDa inositol polyphosphate 5-phosphatase in cHCC-CCA, were highly correlated with tumor stage, tumor grade, recurrence-free survival, and overall survival. Postproteomic site-specific N-glycan analyses showed that human complement C3 bears high-mannose and hybrid glycoforms rather than complex glycoforms at Asn85. The abundance of complement C3 with mannose-5 or mannose-6 glycoform at Asn85 was associated with HCC tumor grade. Furthermore, stepwise Cox regression analyses revealed that HCC patients with a hybrid glycoform at Asn85 of complement C3 had a lower postsurgery tumor recurrence rate or mortality rate than those with a low amount of complement C3 protein. In conclusion, our data show that particular plasma N-glycoproteins with specific N-glycan compositions could be potential noninvasive markers to evaluate oncological status and prognosis of hepatobiliary cancers.

Etifoxine, a TSPO Ligand, Worsens Hepatitis C-Related Insulin Resistance but Relieves Lipid Accumulation.

Etifoxine, an 18 kDa translocator protein (TSPO) agonist for the treatment of anxiety disorders in clinic, may be able to cause acute liver injury or cytolytic hepatitis. TSPO has been demonstrated to participate in inflammatory responses in infective diseases as well as to modulate glucose and lipid homeostasis. Hepatitis C virus (HCV) infection disrupts glucose and lipid homoeostasis, leading to insulin resistance (IR). Whether TSPO affects the HCV-induced IR remains unclear. Here, we found that the administration of etifoxine increased the TSPO protein expression and recovered the HCV-mediated lower mitochondrial membrane potential (MMP) without affecting HCV infection. Moreover, etifoxine reversed the HCV-induced lipid accumulation by modulating the expressions of sterol regulatory element-binding protein-1 and apolipoprotein J. On the other hand, in infected cells pretreated with etifoxine, the insulin-mediated insulin receptor substrate-1/Akt signals, forkhead box protein O1 translocation, and glucose uptake were blocked. Taken together, our results pointed out that etifoxine relieved the HCV-retarded MMP and reduced the lipid accumulation but deteriorated the HCV-induced IR by interfering with insulin signal molecules.

ICR suckling mouse model of Zika virus infection for disease modeling and drug validation.

BACKGROUND: Zika virus (ZIKV) infection causes diseases ranging from acute self-limiting febrile illness to life-threatening Guillain-Barré Syndrome and other neurological disorders in adults. Cumulative evidence suggests an association between ZIKV infection and microcephaly in newborn infants. Given the host-range restrictions of the virus, a susceptible animal model infected by ZIKV must be developed for evaluation of vaccines and antivirals. In this study, we propose a convenient mouse model for analysis of neurological disorders caused by ZIKV. METHODOLOGY: Six-day-old immunocompetent ICR suckling mice were used in the experiment. Different inoculum virus concentrations, challenge routes, and challenge times were assessed. Viremic dissemination was determined in the liver, spleen, kidney, and brain through Western blot assay, plaque assay, absolute quantification real-time PCR, and histological observation. Azithromycin, a well-characterized anti-ZIKV compound, was used to evaluate the ICR suckling mouse model for antiviral testing. CONCLUSIONS: Signs of illness and neurological disease and high mortality rate were observed in mice injected with ZIKV intracerebrally (102 to 105) and intraperitoneally (103 to 105). Viremic dissemination was observed in the liver, spleen, kidney, and brain. ZIKV transmitted, rapid replicated, and induced monocyte infiltration into the brain approximately 5 to 6 days post inoculum. Azithromycin conferred protection against ZIKV-caused neurological and life-threatening diseases. The developed model of ZIKV infection and disease can be used for screening drugs against ZIKV and discovering the underlying mechanism of ZIKV pathogenesis.

Calcitriol Inhibits HCV Infection via Blockade of Activation of PPAR and Interference with Endoplasmic Reticulum-Associated Degradation.

Vitamin D has been identified as an innate anti-hepatitis C virus (HCV) agent but the possible mechanisms for this issue remain unclear. Here, we clarified the mechanisms of calcitriol-mediated inhibition of HCV infection. Calcitriol partially inhibited HCV infection, nitric oxide (NO) release and lipid accumulation in Huh7.5 human hepatoma cells via the activation of vitamin D receptor (VDR). When cells were pretreated with the activators of peroxisome proliferator-activated receptor (PPAR)-α (Wy14643) and -γ (Ly171883), the calcitriol-mediated HCV suppression was reversed. Otherwise, three individual stimulators of PPAR-α/ß/γ blocked the activation of VDR. PPAR-ß (linoleic acid) reversed the inhibition of NO release, whereas PPAR-γ (Ly171883) reversed the inhibitions of NO release and lipid accumulation in the presence of calcitriol. The calcitriol-mediated viral suppression, inhibition of NO release and activation of VDR were partially blocked by an inhibitor of endoplasmic reticulum-associated degradation (ERAD), kifunensine. Furthermore, calcitriol blocked the HCV-induced expressions of apolipoprotein J and 78 kDa glucose-regulated protein, which was restored by pretreatment of kifunensine. These results indicated that the calcitriol-mediated HCV suppression was associated with the activation of VDR, interference with ERAD process, as well as blockades of PPAR, lipid accumulation and nitrative stress.

Role of adiponectin gene variants, adipokines and hydrometry-based percent body fat in metabolically healthy and abnormal obesity.

OBJECTIVE: Metabolically healthy obesity (MHO) subjects have better metabolic parameters than metabolically abnormal obesity (MAO) subjects, but the possible mechanisms underlying this remain unknown. Our study was designed to investigate the interrelationships among genes, adipokines, body fat and its distribution in MHO and MAO. METHODS: From 2007 to 2009, 103 males and 131 females aged 18-50 years were enrolled by an intention-to-treat design in a weight management clinic. Participants were divided into MHO and MAO groups. Percent body fat (PBF) was measured by a deuterium oxide dilution method. Four polymorphic variants, including PPARγ2 (Pro12Ala and C1431T) and adiponectin (T45G and G276T) genes, and three adipokines (adiponectin, leptin and resistin) were obtained. RESULTS: Of the 234 obese subjects, 130 (55.6%) were MHO. In the univariate analysis, the MAO group has significantly higher anthropometric, metabolic indices and leptin levels than the MHO group. Logistic regression analysis revealed that age, male gender, the T allele of adiponectin T45G polymorphism, leptin and PBF were positively associated with MAO. ANCOVA analysis revealed that the T allele of adiponectin T45G polymorphism was associated with higher fasting and postprandial glucose levels. We further found that TT genotype has a lower high molecular weight (HMW)/low molecular weight (LMW) adiponectin ratio than GG genotype. CONCLUSIONS: The factors associated with MAO are age, male gender, the T allele of adiponectin T45G polymorphism, leptin, and PBF. The net effects of T45G polymorphism on the MAO phenotype may be achieved by changes in the adiponectin oligomer ratio and glucose levels.

Viral dynamics of persistent hepatitis C virus infection in high-sensitive reporter cells resemble patient's viremia.

BACKGROUND: Hepatitis C virus (HCV) infection has a high persistence rate in patients. Although immune cells play a central role in determining the outcomes of HCV infection, the liver is crucial in controlling HCV activity from acute to chronic stages. This investigation grew HCV from a long-term cell culture, and provided an experimental model for studies on HCV persistence in hepatocytes. METHODS: Huh7.5 cells implanted with the NS3/4 protease-based secreted alkaline phosphatase (SEAP) reporter were infected with JFH-1 HCV (moiety of infection = 0.01) and incubated for over 130 days. RESULTS: The viral activity was obtained by sampling supernatant continuously for SEAP activity measurement. Combined with extracellular and intracellular HCV-RNAs and viral infectivity assays, the experimental results exhibited in vitro viral dynamics resembling the patients' viremia pattern from acute to chronic infections. The HCV in acute infection comprised exponential accumulation (week 1), plateau (week 2), declining production (weeks 3-4) and silencing (weeks 5-14) phases, and were then reactivated at the onset of chronic infection (after week 15). The HCV-infected cells grew more slowly than the mock controls, and exhibited a prominent decrease of cell growth rate and increase of early apoptosis in the declining-to-silencing phase transition, suggesting that fitness selection might occur as the infected cells moved across the boundary of active to occult viral activity. CONCLUSION: Cultivated HCV in the highly sensitive NS3/4-based SEAP reporter cells could establish persistence, which might mimic the viral dynamics from acute to chronic infections in hepatitis C patients.

Favouring modulation of circulating lipoproteins and lipid loading capacity by direct antiviral agents grazoprevir/elbasvir or ledipasvir/sofosbuvir treatment against chronic HCV infection.

OBJECTIVE: Lipid homoeostasis is disturbed in patients with HCV infection. Direct-acting antiviral agent (DAA) treatment eradicates chronic HCV viraemia, but the dynamics of lipid components remain elusive. This study investigates the clinical manifestation and mechanistic relevance of plasma triglyceride (TG), cholesterol (Chol), lipoproteins and apolipoproteins (apos) after DAA treatment. DESIGN: Twenty-four patients with chronic genotype 1 (GT1) HCV treated with elbasvir/grazoprevir or ledipasvir/sofosbuvir for 12 weeks, and followed-up thereafter, were recruited. Their TG, Chol, apoAI and apoB levels were quantified in plasma samples and individually fractionated lipoprotein of various classes. Liver fibrosis was evaluated using the FIB-4 Score. The TG and Chol loading capacities were calculated with normalisation to apoB, which represents per very low density lipoprotein (VLDL) and LDL particle unit RESULTS: DAA treatment achieved a sustained virological response rate of 91.7% and reduced the FIB-4 Score. Relative to the baseline, the plasma TG level was reduced but the Chol level increased gradually. Plasma apoB levels and apoB/apoAI ratio were transiently downregulated as early as the first 4 weeks of treatment. The TG and Chol loading capacities in VLDL were elevated by ~20% during the period of DAA treatment and had steadily increased by 100% at follow-up. Furthermore, the TG-to-Chol ratio in VLDL was increased, while the ratio in LDL was reduced, indicating an efficient catabolism. CONCLUSION: The DAA treatment of patients with chronic hepatitis C might lead to efficient HCV eradication and hepatic improvement concomitantly evolving with favouring lipoprotein/apo metabolisms.

Celastrol inhibits hepatitis C virus replication by upregulating heme oxygenase-1 via the JNK MAPK/Nrf2 pathway in human hepatoma cells.

BACKGROUND AND PURPOSE: Celastrol, a quinone methide triterpene isolated from the root extracts of Tripterygium wilfordii, can greatly induce the gene expression activity of heme oxygenase-1 (HO-1) to achieve disease prevention and control. HO-1 induction was recently shown to result in anti-HCV activity by inducing type I interferon and inhibiting hepatitis C virus (HCV) NS3/4A protease activity. The aim of the present study is to evaluate the anti-HCV activity of celastrol and characterize its mechanism of inhibition. METHODS: The anti-HCV activity of celastrol was evaluated using the HCV subgenomic replicon and HCVcc infection systems. The anti-HCV mechanism of celastrol targeting HO-1 expression was clarified using specific inhibitors against several signaling pathways. The transcriptional regulation of celastrol on target gene expression was determined using promoter-based reporter activity assay. The synergistic effect of celastrol and a numbers of clinically used anti-HCV drugs was determined via a drug combination assay. RESULTS: Celastrol inhibited HCV replication in both the HCV subgenomic and HCVcc infection systems with EC50 values of 0.37 ± 0.022 and 0.43 ± 0.019 µM, respectively. Celastrol-induced heme oxygenase 1 (HO-1) expression promoted antiviral interferon responses and inhibition of NS3/4A protease activity, thereby blocking HCV replication. These antiviral effects were abrogated by treatment with the HO-1-specific inhibitor SnMP or silencing of HO-1 expression by transfection of shRNA, which indicates that HO-1 induction contributes to the anti-HCV activity of celastrol. JNK mitogen-activated protein kinase and nuclear factor erythroid 2-related factor 2 (Nrf2) were confirmed to be involved in the inductive effect of celastrol on HO-1 expression. Celastrol exhibited synergistic effects in combination with interferon-alpha, the NS5A inhibitor daclatasvir, and the NS5B inhibitor sofosbuvir. CONCLUSION: Celastrol can serve as a potential supplement for blocking HCV replication. Targeting the JNK/Nrf2/HO-1 axis presents a promising strategy against HCV infection.

Lipoprotein lipase liberates free fatty acids to inhibit HCV infection and prevent hepatic lipid accumulation.

Lipoprotein lipase (LPL) has been identified as an anti-hepatitis C virus (HCV) host factor, but the cellular mechanism remains elusive. Here, we investigated the cellular mechanism of LPL involving in anti-HCV. The functional activation of peroxisome proliferator-activated receptor (PPAR) α signal by LPL transducing into hepatocytes was investigated in HCV-infected cells, primary human hepatocytes, and in HCV-core transgenic mice. The result showed that the levels of transcriptional transactivity and nuclear translocation of PPARα in Huh7 cells and primary human hepatocytes were elevated by physiologically ranged LPL treatment of either very-low density lipoprotein or HCV particles. The LPL-induced hepatic PPARα activation was weakened by blocking the LPL enzymatic activity, and by preventing the cellular uptake of free unsaturated fatty acids with either albumin chelator or silencing of CD36 translocase. The knockdowns of PPARα and CD36 reversed the LPL-mediated suppression of HCV infection. Furthermore, treatment with LPL, like the direct activation of PPARα, not only reduced the levels of apolipoproteins B, E, and J, which are involved in assembly and release of HCV virions, but also alleviated hepatic lipid accumulation induced by core protein. HCV-core transgenic mice exhibited more hepatic miR-27b, which negatively regulates PPARα expression, than did the wild-type controls. The induction of LPL activity by fasting in the core transgenic mice activated PPARα downstream target genes that are involved in fatty acid ß-oxidation. Taken together, our study reveals dual beneficial outcomes of LPL in anti-HCV and anti-steatosis and shed light on the control of chronic hepatitis C in relation to LPL modulators.

Characterization of thermoplastic microfiltration chip for the separation of blood plasma from human blood.

In this study, we developed a fully thermoplastic microfiltration chip for the separation of blood plasma from human blood. Spiral microchannels were manufactured on a PMMA substrate using a micromilling machine, and a commercial polycarbonate membrane was bonded between two thermoplastic substrates. To achieve an excellent bonding between the commercial membrane and the thermoplastic substrates, we used a two-step injection and curing procedure of UV adhesive into a ring-shaped structure around the microchannel to efficiently prevent leakage during blood filtration. We performed multiple filtration experiments using human blood to compare the influence of three factors on separation efficiency: hematocrit level (40%, 23.2%, and 10.9%), membrane pore size (5 µm, 2 µm, and 1 µm), and flow rate (0.02 ml/min, 0.06 ml/min, 0.1 ml/min). To prevent hemolysis, the pressure within the microchannel was kept below 0.5 bars throughout all filtration experiments. The experimental results clearly demonstrated the following: (1) The proposed microfiltration chip is able to separate white blood cells and red blood cells from whole human blood with a separation efficiency that exceeds 95%; (2) no leakage occurred during any of the experiments, thereby demonstrating the effectiveness of bonding a commercial membrane with a thermoplastic substrate using UV adhesive in a ring-shaped structure; (3) separation efficiency can be increased by using a membrane with smaller pore size, by using diluted blood with lower hematocrit, or by injecting blood into the microfiltration chip at a lower flow rate.

Fluoxetine regulates cell growth inhibition of interferon-α.

Fluoxetine, a well-known anti-depression agent, may act as a chemosensitizer to assist and promote cancer therapy. However, how fluoxetine regulates cellular signaling to enhance cellular responses against tumor cell growth remains unclear. In the present study, addition of fluoxetine promoted growth inhibition of interferon-alpha (IFN-α) in human bladder carcinoma cells but not in normal uroepithelial cells through lessening the IFN-α-induced apoptosis but switching to cause G1 arrest, and maintaining the IFN-α-mediated reduction in G2/M phase. Activations and signal transducer and transactivator (STAT)-1 and peroxisome proliferator-activated receptor alpha (PPAR-α) were involved in this process. Chemical inhibitions of STAT-1 or PPAR-α partially rescued bladder carcinoma cells from IFN-α-mediated growth inhibition via blockades of G1 arrest, cyclin D1 reduction, p53 downregulation and p27 upregulation in the presence of fluoxetine. However, the functions of both proteins were not involved in the control of fluoxetine over apoptosis and maintained the declined G2/M phase of IFN-α. These results indicated that activation of PPAR-α and STAT-1 participated, at least in part, in growth inhibition of IFN-α in the presence of fluoxetine.

Human heme oxygenase 1 is a potential host cell factor against dengue virus replication.

Dengue virus (DENV) infection and replication induces oxidative stress, which further contributes to the progression and pathogenesis of the DENV infection. Modulation of host antioxidant molecules may be a useful strategy for interfering with DENV replication. In this study, we showed that induction or exogenous overexpression of heme oxygenase-1 (HO-1), an antioxidant enzyme, effectively inhibited DENV replication in DENV-infected Huh-7 cells. This antiviral effect of HO-1 was attenuated by its inhibitor tin protoporphyrin (SnPP), suggesting that HO-1 was an important cellular factor against DENV replication. Biliverdin but not carbon monoxide and ferrous ions, which are products of the HO-1 on heme, mediated the HO-1-induced anti-DENV effect by non-competitively inhibiting DENV protease, with an inhibition constant (Ki) of 8.55 ± 0.38 µM. Moreover, HO-1 induction or its exogenous overexpression, rescued DENV-suppressed antiviral interferon response. Moreover, we showed that HO-1 induction by cobalt protoporphyrin (CoPP) and andrographolide, a natural product, as evidenced by a significant delay in the onset of disease and mortality, and virus load in the infected mice's brains. These findings clearly revealed that a drug or therapy that induced the HO-1 signal pathway was a promising strategy for treating DENV infection.