ABSTRACT
BACKGROUND AND AIMS: Mutations within the precore (PC) and basal core promoter (BCP) regions of the HBV genome are associated with fulminant hepatitis and HBV reactivation. These mutations may enhance viral replication, but little is known about whether they directly induce damage to the liver. We investigated mechanisms of direct cytopathic effects induced by the infection with PC/BCP mutants in the absence of immune response in vitro and in vivo . APPROACH AND RESULTS: Mice with humanized livers and hepatocytes derived from humanized mice were infected with either wild-type or mutant-type PC/BCP HBV, and the HBV replication and human hepatocyte damage were evaluated. HBV proliferated vigorously in mice with PC/BCP-mutant infection, and the severe loss of human hepatocytes with a slight human ALT elevation subsequently occurred only in PC/BCP mutant mice. In PC/BCP mutant infection, the accumulation of HBsAg in humanized livers colocalized with the endoplasmic reticulum, leading to apoptosis through unfolded protein response in HBV-infected hepatocytes. RNA-sequencing revealed the molecular characteristics of the phenotype of PC/BCP mutant infection in a humanized mouse model. Reduced ALT elevation and higher HBV DNA levels in this model are consistent with characteristics of HBV reactivation, indicating that the hepatocyte damage in this model might mimic HBV reactivation followed by hepatocyte damage under immunosuppressive conditions. CONCLUSION: PC and BCP mutations were associated with enhanced viral replication and cell death induced by ER stress using HBV infection models. These mutations might be associated with liver damage in patients with fulminant hepatitis or HBV reactivation.
Subject(s)
Hepatitis B virus , Massive Hepatic Necrosis , Humans , Animals , Mice , Mutation , Phenotype , Cell Death , DNA, Viral/genetics , Genotype , Hepatitis B e Antigens/geneticsABSTRACT
Mitochondrial quality is controlled by the selective removal of damaged mitochondria through mitophagy. Mitophagy impairment is associated with aging and many pathological conditions. An iron loss induced by iron chelator triggers mitophagy by a yet unknown mechanism. This type of mitophagy may have therapeutic potential, since iron chelators are clinically used. Here, we aimed to clarify the mechanisms by which iron loss induces mitophagy. Deferiprone, an iron chelator, treatment resulted in the increased expression of mitochondrial ferritin (FTMT) and the localization of FTMT precursor on the mitochondrial outer membrane. Specific protein 1 and its regulator hypoxia-inducible factor 1α were necessary for deferiprone-induced increase in FTMT. FTMT specifically interacted with nuclear receptor coactivator 4, an autophagic cargo receptor. Deferiprone-induced mitophagy occurred selectively for depolarized mitochondria. Additionally, deferiprone suppressed the development of hepatocellular carcinoma (HCC) in mice by inducing mitophagy. Silencing FTMT abrogated deferiprone-induced mitophagy and suppression of HCC. These results demonstrate the mechanisms by which iron loss induces mitophagy and provide a rationale for targeting mitophagic activation as a therapeutic strategy.
Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Animals , Ferritins/genetics , Iron/metabolism , Mice , Mitochondrial Proteins/metabolism , MitophagyABSTRACT
BACKGROUND: Hereditary hemochromatosis is a heterogenous group of inherited iron-overload conditions that is characterized by increased intestinal absorption and deposition in vital organs. Hepcidin is a soluble regulator that acts to attenuate both intestinal iron absorption and iron release from reticuloendothelial macrophages through internalization of ferroportin-1, an iron exporter. Ferroportin disease is hereditary hemochromatosis which is affected by SLC40A1, a gene coding ferroportin-1, and phenotypically classified into two forms (classical and nonclassical). In nonclassical form, ferroportin mutations are responsible for a gain of function with full iron export capability but insensitivity to downregulation by hepcidin. Here, we report a case of nonclassical ferroportin disease. CASE PRESENTATION: A 46-year-old Japanese man showed elevated serum iron (284 µg/dl), ferritin (1722 ng/ml), transferrin saturation ratio (91.3%), and hepcidin-25 level (139.6 ng/ml). Magnetic resonance imaging (MRI) demonstrated a marked reduction in the signal intensity of the liver in T1- and T2-weighted images. The liver histology exhibited a large amount of iron that had accumulated predominantly in hepatocytes. We identified a heterozygous 1520A > G (p.H507R) mutation in the SLC40A1 gene. Phlebotomy (400 ml at a time) was monthly performed for 3 years in this patient. Importantly, the serum hepcidin level (1.0 ng/ml) was normal when the serum ferritin level was normal and hepatic iron accumulation was remarkably reduced after 3 years of phlebotomy. CONCLUSIONS: The present case demonstrated for the first time that there was a correlation between hepatic iron levels as measured by MRI and serum hepcidin levels through long-term phlebotomy in a patient with ferroportin disease with the p.H507R mutation of in SLC40A1.
Subject(s)
Cation Transport Proteins/genetics , Hemochromatosis , Hemochromatosis/genetics , Hemochromatosis/therapy , Humans , Iron , Male , Middle Aged , Mutation , PhlebotomyABSTRACT
Hepatitis C virus (HCV) infection has been known to use autophagy for its replication. However, the mechanisms by which HCV modulates autophagy remain controversial. We used HCV-Japanese fulminant hepatitis-1-infected Huh7 cells. HCV infection induced the accumulation of autophagosomes. Morphological analyses of monomeric red fluorescent protein (mRFP)-green fluorescent protein (GFP) tandem fluorescent-tagged LC3 transfection showed HCV infection impaired autophagic flux. Autophagosome-lysosome fusion assessed by transfection of mRFP- or GFP-LC3 and immunostaining of lysosomal-associated membrane protein 1 was inhibited by HCV infection. Decrease of HCV-induced endoplasmic reticulum (ER) stress by 4-phenylbutyric acid, a chemical chaperone, improved the HCV-mediated autophagic flux impairment. HCV infection-induced oxidative stress and subsequently DNA damage, but not apoptosis. Furthermore, HCV induced cytoprotective effects against the cellular stress by facilitating the formation of cytoplasmic inclusion bodies as shown by p62 expression and by modulating keratin protein expression and activated nuclear factor erythroid 2-related factor 2. HCV eradication by direct-acting antivirals improved autophagic flux, but DNA damage persisted. In conclusion, HCV-induced ER stress correlates with autophagic flux impairment. Decrease of ER stress is considered to be a promising therapeutic strategy for HCV-related chronic liver diseases. However, we should be aware that the risk of hepatocarcinogenesis remains even after HCV eradication.
Subject(s)
Autophagy , Carcinogenesis , Endoplasmic Reticulum Stress , Hepatitis C/physiopathology , Liver/physiopathology , Cell Line , Gene Expression Regulation , Hepatitis C/complications , Hepatitis C/genetics , Humans , Keratins/genetics , Liver/metabolism , Liver Neoplasms/etiology , Liver Neoplasms/pathology , NF-E2-Related Factor 2/geneticsABSTRACT
AIM: As it is not practical to perform regular screening for hepatocellular carcinoma (HCC) in all patients with non-alcoholic fatty liver disease (NAFLD), there is a need to identify NAFLD patients who are at high risk for HCC. Wisteria floribunda agglutinin-positive Mac-2 binding protein (WFA+ -M2BP) has been shown to be a surrogate marker for predicting HCC as well as a liver fibrosis marker in patients with chronic hepatitis B and C. The aim of this study was to investigate whether WFA+ -M2BP predicts HCC development in NAFLD patients. METHODS: Serum WFA+ -M2BP was retrospectively measured in 331 patients with histologically proven NAFLD, 51 of whom developed HCC. The association of WFA+ -M2BP and HCC development in NAFLD patients was investigated. RESULTS: The WFA+ -M2BP values were significantly greater in NAFLD patients with HCC than in those without HCC among patients with liver fibrosis ≥stage 3. Multivariate analysis identified WFA+ -M2BP as one of the predictive factors for HCC development (odds ratio, 1.57; 95% confidence interval, 1.083-2.265; P = 0.017). The optimal cut-off index of WFA+ -M2BP for predicting HCC was 1.255 with specificity of 78.4% and sensitivity of 70.4%. The area under the receiver operating characteristic curve value for the prediction of HCC development was 0.806. The cumulative incidence rate of HCC was significantly greater in patients with WFA+ -M2BP ≥ 1.255 (n = 61) than in those with WFA+ -M2BP < 1.255 (n = 137) among patients who were followed up for more than 2 years after the diagnosis of NAFLD. CONCLUSIONS: Wisteria floribunda agglutinin-positive Mac-2 binding protein predicts HCC development and is a useful surrogate marker for identifying NAFLD patients who are at a high risk for HCC.
ABSTRACT
Hepatitis C virus (HCV) causes mitochondrial injury and oxidative stress, and impaired mitochondria are selectively eliminated through autophagy-dependent degradation (mitophagy). We investigated whether HCV affects mitophagy in terms of mitochondrial quality control. The effect of HCV on mitophagy was examined using HCV-Japanese fulminant hepatitis-1-infected cells and the uncoupling reagent carbonyl cyanide m-chlorophenylhydrazone as a mitophagy inducer. In addition, liver cells from transgenic mice expressing the HCV polyprotein and human hepatocyte chimeric mice were examined for mitophagy. Translocation of the E3 ubiquitin ligase Parkin to the mitochondria was impaired without a reduction of pentaerythritol tetranitrate-induced kinase 1 activity in the presence of HCV infection both in vitro and in vivo. Coimmunoprecipitation assays revealed that Parkin associated with the HCV core protein. Furthermore, a Yeast Two-Hybrid assay identified a specific interaction between the HCV core protein and an N-terminal Parkin fragment. Silencing Parkin suppressed HCV core protein expression, suggesting a functional role for the interaction between the HCV core protein and Parkin in HCV propagation. The suppressed Parkin translocation to the mitochondria inhibited mitochondrial ubiquitination, decreased the number of mitochondria sequestered in isolation membranes, and reduced autophagic degradation activity. Through a direct interaction with Parkin, the HCV core protein suppressed mitophagy by inhibiting Parkin translocation to the mitochondria. This inhibition may amplify and sustain HCV-induced mitochondrial injury.
Subject(s)
Hepatitis C Antigens/metabolism , Mitochondria/metabolism , Mitophagy/physiology , Ubiquitin-Protein Ligases/metabolism , Viral Core Proteins/metabolism , Animals , Hepatocytes/metabolism , Liver/metabolism , Mice , Mice, Transgenic , Oxidative Stress/physiology , Protein Transport , UbiquitinationABSTRACT
BACKGROUND & AIMS: Branched-chain amino acids (BCAA) reduce the incidence of hepatocellular carcinoma (HCC) in patients with cirrhosis. However, the mechanisms that underlie these effects remain unknown. Previously, we reported that oxidative stress in male transgenic mice that expressed hepatitis C virus polyprotein (HCVTgM) caused hepatic iron accumulation by reducing hepcidin transcription, thereby leading to HCC development. This study investigated whether long-term treatment with BCAA reduced hepatic iron accumulation and oxidative stress in iron-overloaded HCVTgM and in patients with HCV-related advanced fibrosis. METHODS: Male HCVTgM were fed an excess-iron diet that comprised either casein or 3.0% BCAA, or a control diet, for 6 months. RESULTS: For HCVTgM, BCAA supplementation increased the serum hepcidin-25 levels and antioxidant status [ratio of biological antioxidant potential (BAP) relative to derivatives of reactive oxygen metabolites (dROM)], decreased the hepatic iron contents, attenuated reactive oxygen species generation, and restored mitochondrial superoxide dismutase expression and mitochondrial complex I activity in the liver compared with mice fed the control diet. After 48 weeks of BCAA supplementation in patients with HCV-related advanced fibrosis, BAP/dROM and serum hepcidin-25 increased and serum ferritin decreased compared with the pretreatment levels. CONCLUSIONS: BCAA supplementation reduced oxidative stress by restoring mitochondrial function and improved iron metabolism by increasing hepcidin-25 in both iron-overloaded HCVTgM and patients with HCV-related advanced fibrosis. These activities of BCAA may partially account for their inhibitory effects on HCC development in cirrhosis patients.
Subject(s)
Amino Acids, Branched-Chain/administration & dosage , Dietary Proteins/administration & dosage , Hepacivirus/metabolism , Hepatitis C/diet therapy , Iron/metabolism , Liver Cirrhosis/diet therapy , Liver/metabolism , Oxidative Stress , Polyproteins/metabolism , Viral Proteins/metabolism , Aged , Aged, 80 and over , Animals , Antioxidants/metabolism , Biomarkers/blood , Disease Models, Animal , Female , Ferritins/blood , Hepacivirus/genetics , Hepatitis C/blood , Hepatitis C/genetics , Hepatitis C/metabolism , Hepcidins/blood , Humans , Japan , Liver Cirrhosis/blood , Liver Cirrhosis/genetics , Liver Cirrhosis/metabolism , Male , Mice, Transgenic , Polyproteins/genetics , Reactive Oxygen Species/blood , Time Factors , Treatment Outcome , Viral Proteins/geneticsABSTRACT
BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is characterized by an extensive desmoplastic stromal response. Fibroblast activation protein-α (FAP) is best known for its presence in stromal cancer-associated fibroblasts (CAFs). Our aim was to assess whether FAP expression was associated with the prognosis of patients with PDAC and to investigate how FAP expressing CAFs contribute to the progression of PDAC. METHODS: FAP expression was immunohistochemically assessed in 48 PDAC specimens. We also generated a fibroblastic cell line stably expressing FAP, and examined the effect of FAP-expressing fibroblasts on invasiveness and the cell cycle in MiaPaCa-2 cells (a pancreatic cancer cell line). RESULTS: Stromal FAP expression was detected in 98% (47/48) of the specimens of PDAC, with the intensity being weak in 16, moderate in 19, and strong in 12 specimens, but was not detected in the 3 control noncancerous pancreatic specimens. Patients with moderate or strong FAP expression had significantly lower cumulative survival rates than those with negative or weak FAP expression (mean survival time; 352 vs. 497 days, P = 0.006). Multivariate analysis identified moderate to strong expression of FAP as one of the factors associated with the prognosis in patients with PDAC. The intensity of stromal FAP expression was also positively correlated to the histological differentiation of PDAC (P < 0.05). FAP-expressing fibroblasts promoted the invasiveness of MiaPaCa-2 cells more intensively than fibroblasts not expressing FAP. Coculture with FAP-expressing fibroblasts significantly activated cell cycle shift in MiaPaCa-2 cells compared to coculture with fibroblasts not expressing FAP. Furthermore, coculture with FAP expressing fibroblasts inactivated retinoblastoma (Rb) protein, an inhibitor of cell cycle progression, in MiaPaCa-2 cells by promoting phosphorylation of Rb. CONCLUSIONS: The present in vitro results and the association of FAP expression with clinical outcomes provide us with a better understanding of the effect of FAP-expressing CAFs on the progression of PDAC.
Subject(s)
Carcinoma, Pancreatic Ductal/pathology , Fibroblasts/metabolism , Gelatinases/metabolism , Membrane Proteins/metabolism , Pancreatic Neoplasms/pathology , Serine Endopeptidases/metabolism , Aged , Carcinoma, Pancreatic Ductal/chemistry , Cell Cycle Checkpoints , Cell Line, Tumor , Coculture Techniques , Disease Progression , Endopeptidases , Female , Gelatinases/analysis , Gelatinases/genetics , Humans , Male , Membrane Proteins/analysis , Membrane Proteins/genetics , Middle Aged , Neoplasm Invasiveness , Pancreas/chemistry , Pancreatic Neoplasms/chemistry , Phosphorylation , Prognosis , Retinoblastoma Protein/metabolism , Serine Endopeptidases/analysis , Serine Endopeptidases/genetics , Survival RateABSTRACT
There are several lines of evidence suggesting that oxidative stress is present in hepatitis C to a greater degree than in other inflammatory liver diseases and is closely related to disease progression. The main production site of reactive oxygen species (ROS) is assumed to be mitochondria, which concept is supported by evidence that hepatitis C virus (HCV) core protein is directly associated with them. The detoxification of ROS also is an important function of the cellular redox homeostasis system. These results draw our attention to how HCV-induced mitochondrial ROS production is beyond redox regulation and affects the disease progression and development of hepatocellular carcinoma (HCC) in chronic hepatitis C. On the other hand, HCV-related chronic liver diseases are characterized by metabolic alterations such as insulin resistance, hepatic steatosis and/or iron accumulation in the liver. These metabolic disorders also are relevant to the development of HCC in HCV-related chronic liver diseases. Here, we review the mechanisms by which HCV increases mitochondrial ROS production and offer new insights as to how mitochondrial ROS are linked to metabolic disorders such as insulin resistance, hepatic steatosis and hepatic iron accumulation that are observed in HCV-related chronic liver diseases.
ABSTRACT
AIM: Oxidative stress plays an important role in hepatocarcinogenesis of hepatitis C virus (HCV)-related chronic liver diseases. Despite the evidence of an increased proportion of females among elderly patients with HCV-related hepatocellular carcinoma (HCC), it remains unknown whether HCV augments hepatic oxidative stress in postmenopausal women. The aim of this study was to determine whether oxidative stress was augmented in ovariectomized (OVX) transgenic mice expressing the HCV polyprotein and to investigate its underlying mechanisms. METHODS: OVX and sham-operated female transgenic mice expressing the HCV polyprotein and non-transgenic littermates were assessed for the production of reactive oxygen species (ROS), expression of inflammatory cytokines and antioxidant potential in the liver. RESULTS: Compared with OVX non-transgenic mice, OVX transgenic mice showed marked hepatic steatosis and ROS production without increased induction of inflammatory cytokines, but there was no increase in ROS-detoxifying enzymes such as superoxide dismutase 2 and glutathione peroxidase 1. In accordance with these results, OVX transgenic mice showed less activation of peroxisome proliferator-activated receptor-γ co-activator-1α (PGC-1α), which is required for the induction of ROS-detoxifying enzymes, and no activation of adenosine monophosphate-activated protein kinase-α (AMPKα), which regulates the activity of PGC-1α. CONCLUSION: Our study demonstrated that hepatic oxidative stress was augmented in OVX transgenic mice expressing the HCV polyprotein by attenuation of antioxidant potential through inhibition of AMPK/PGC-1α signaling. These results may account in part for the mechanisms by which HCV-infected women are at high risk for HCC development when some period has passed after menopause.
ABSTRACT
AIM: Little is known about the effects of non-alcoholic fatty liver disease (NAFLD) on energy metabolism, although this disease is associated with metabolic syndrome. We measured non-protein respiratory quotient (npRQ) using indirect calorimetry, which reflects glucose oxidation, and compared this value with histological disease severity in NAFLD patients. METHODS: Subjects were 32 patients who were diagnosed with NAFLD histopathologically. Subjects underwent body composition analysis and indirect calorimetry, and npRQ was calculated. An oral glucose tolerance test was performed, and plasma glucose area under the curve (AUC glucose) was calculated. RESULTS: There were no differences in body mass index, body fat percentage or visceral fat area among fibrosis stage groups. As fibrosis progressed, npRQ significantly decreased (stage 0, 0.895 ± 0.068; stage 1, 0.869 ± 0.067; stage 2, 0.808 ± 0.046; stage 3, 0.798 ± 0.026; P < 0.005). Glucose intolerance worsened and insulin resistance increased with fibrosis stage. npRQ was negatively correlated with AUC glucose (R = -0.6308, P < 0.001), Homeostasis Model of Assessment - Insulin Resistance (R = -0.5045, P < 0.005), fasting glucose (R = -0.4585, P < 0.01) and insulin levels (R = -0.4431, P < 0.05), suggesting that decreased npRQ may reflect impaired glucose tolerance due to insulin resistance, which was associated with fibrosis progression. Estimation of fibrosis stage using npRQ was as accurate as several previously established scoring systems using receiver-operator curve analysis. CONCLUSION: npRQ was significantly decreased in patients with advanced NAFLD. Our data suggest that measurement of npRQ is useful for the estimation of disease severity in NAFLD patients.
ABSTRACT
The liver is the major iron storage organ in the body, and therefore, iron metabolic disorder is sometimes involved in chronic liver diseases. Chronic hepatitis C is one of the liver diseases that show hepatic iron accumulation, even though its level should be recognized to be basically mild to moderate and sometimes within the normal range. The mechanisms underlying hepatic iron accumulation in chronic hepatitis C have not been fully elucidated. Reduction of the hepcidin transcription activity by hepatitis C virus (HCV)-induced reactive oxygen species may in part account for it, but the regulation of hepcidin is very complex and may depend on many variables, including the particular stage of the systemic and/or hepatic inflammatory conditions and the circulating transferrin-bound iron and intracellular iron stores. This might explain the variations in hepatic iron concentrations reported among patients with HCV-related chronic liver disease. However, even mild-to-moderate iron overload in the liver contributes to disease progression and hepatocarcinogenesis in chronic hepatitis C probably by reinforcing the HCV-induced oxidative stress through Fenton reaction. The present review highlights the current concept of hepatic iron overload status in chronic hepatitis C and discusses how iron metabolic disorder develops in this disease and the impact of hepatic iron overload on disease progression and its relevance to hepatocarcinogenesis.
Subject(s)
Carcinoma, Hepatocellular/etiology , Hepatitis C, Chronic/complications , Iron Metabolism Disorders/complications , Liver Neoplasms/etiology , Disease Progression , Hepatitis C, Chronic/metabolism , Hepcidins/genetics , Hepcidins/metabolism , Homeostasis , Humans , Iron/metabolism , Liver/metabolism , Oxidative Stress/physiology , Reactive Oxygen Species/metabolism , Transcription, Genetic , Transferrin/metabolismABSTRACT
Asymmetric dye clusters with a single fluorophore (Cy3) and multiple quenchers (4'-methylthioazobenzene-4-carboxylate, methyl red, and 4'-dimethylamino-2-nitroazobenzene-4-carboxylate) were prepared. The dye and one-to-five quenchers were tethered through D-threoninol to opposite strands of a DNA duplex. NMR analysis revealed that the clusters with a single fluorophore and two quenchers formed a sandwich-like structure (antiparallel H-aggregates). The melting temperatures of all the heteroclusters were almost the same, although structural distortion should become larger, as the number of quenchers increased. An asymmetric heterocluster of a single fluorophore and two quenchers showed larger excitonic interaction (i.e., hypochromicity of Cy3), than did a single Cy3 and a single quencher. Due to the larger exciton coupling between the dyes, the 1:2 heterocluster suppressed the background emission more efficiently than the 1:1 cluster. However, more quenchers did not enhance quenching efficiency due to the saturation of exciton coupling with two quenchers. Finally, this asymmetric 1:2 heterocluster was introduced into the stem region of a molecular beacon (MB; also known as an in-stem MB) targeting the fusion site in the L6 BCR-ABL fusion gene. With this MB design, the signal/background ratio was as high as 68 due to efficient suppression of background emission resulting from the maximized excitonic interaction.
Subject(s)
DNA/analysis , Fluorescent Dyes/chemistry , Molecular Probes/chemistry , Amino Alcohols/chemistry , Azo Compounds , Base Sequence , Butylene Glycols/chemistry , Carbocyanines , Carboxylic Acids/chemistry , Genes, abl , Humans , Magnetic Resonance Spectroscopy , Models, Molecular , Molecular Conformation , Molecular Sequence Data , Nucleic Acid Denaturation , Organic Chemicals , Spectrometry, Fluorescence , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , TemperatureABSTRACT
In this study, we synthesized a simple but efficient quencher-free molecular beacon tethering 7-hydroxycoumarin on D-threoninol based on its pK(a) change. The pK(a) of 7-hydroxycoumarin in a single strand was determined as 8.8, whereas that intercalated in the duplex was over 10. This large pK(a) shift (more than 1.2) upon hybridization could be attributed to the anionic and hydrophobic microenvironment inside the DNA duplex. Because 7-hydroxycoumarin quenches its fluorescence upon protonation, the emission intensity of the duplex at pH 8.5 was 1/15 that of the single strand. We applied this quenching mechanism to the preparation of a quencher-free molecular beacon by introducing the dye into the middle of the stem part. In the absence of the target, the stem region formed a duplex and fluorescence was quenched. However, when the target was added, the molecular beacon opened and the dye was deprotonated. As a result, the emission intensity of the molecular beacon with the target was 10 times higher than that without the target. Accordingly, a quencher-free molecular beacon utilizing the pK(a) change was successfully developed.
Subject(s)
Intercalating Agents/chemistry , Umbelliferones/chemistry , Amino Alcohols/chemistry , Butylene Glycols/chemistry , DNA/chemistry , DNA/metabolism , Hydrogen-Ion Concentration , Intercalating Agents/chemical synthesis , Kinetics , Nucleic Acid Denaturation , Nucleic Acid Hybridization , ProtonsABSTRACT
Iron is an essential element for all organisms. Iron-containing proteins play critical roles in cellular functions. The biological importance of iron is largely attributable to its chemical properties as a transitional metal. However, an excess of 'free' reactive iron damages the macromolecular components of cells and cellular DNA through the production of harmful free radicals. On the contrary, most of the body's excess iron is stored in the liver. Not only hereditary haemochromatosis but also some liver diseases with mild-to-moderate hepatic iron accumulation, such as chronic hepatitis C, alcoholic liver disease and nonalcoholic steatohepatitis, are associated with a high risk for liver cancer development. These findings have attracted attention to the causative and promotive roles of iron in the development of liver cancer. In the last decade, accumulating evidence regarding molecules regulating iron metabolism or iron-related cell death programmes such as ferroptosis has shed light on the relationship between hepatic iron accumulation and hepatocarcinogenesis. In this review, we briefly present the current molecular understanding of iron regulation in the liver. Next, we describe the mechanisms underlying dysregulated iron metabolism depending on the aetiology of liver diseases. Finally, we discuss the causative and promotive roles of iron in cancer development.
Subject(s)
Hemochromatosis , Iron Overload , Liver Neoplasms , Humans , Iron/metabolism , Liver/metabolism , Liver Neoplasms/genetics , Liver Neoplasms/metabolism , Hemochromatosis/genetics , Hemochromatosis/metabolism , Iron Overload/complications , Iron Overload/metabolismABSTRACT
Carboxymethyl cellulose (CMC) is a promising material for moist wound healing, and silver loading onto CMC has been examined for anti-bacterial activity. In this study, we developed silver-loaded CMC nonwoven sheets with different counterions, namely sodium CMC (CMC-Na/Ag) and partially protonated CMC (CMC-H/Ag), to examine their anti-bacterial and wound-healing properties. Owing to the presence of counter protons, CMC-H/Ag showed slower water adsorption, dissolution, and Ag release than CMC-Na/Ag. In addition, CMC-H/Ag and CMC-Na/Ag exhibited differences in anti-bacterial activities in shake-flask and inhibition zone tests in vitro. An in vivo experiment using a pressure ulcer mouse model with Pseudomonas aeruginosa infection showed that CMC-Na/Ag significantly accelerated wound healing compared to CMC-H/Ag and a commercially available Ag-loaded CMC nonwoven sheet, Aquacel Ag. These results suggest the importance of controlling CMC counterions and the therapeutic potential of the developed product as a wound dressing.
Subject(s)
Silver , Wound Infection , Animals , Bandages , Carboxymethylcellulose Sodium/pharmacology , Mice , Silver/pharmacology , Silver/therapeutic use , Wound Healing , Wound Infection/drug therapyABSTRACT
BACKGROUND & AIMS: Immune checkpoint inhibitors have shed light on the importance of antitumor immunity as a therapeutic strategy for hepatocellular carcinoma (HCC). The altered glucose metabolism known as the Warburg effect recently has gained attention as a cancer immune-resistance mechanism. Considering glycolysis inhibitors as therapeutic agents, their specific delivery to cancer cells is critical not to induce adverse effects. Thus, we investigated antitumor effects of a glycolysis inhibitor, consisting of 2-deoxy-D-glucose (2DG)-encapsulated poly(lactic-co-glycolic acid) (PLGA) nanoparticles (2DG-PLGA-NPs), against hepatocellular carcinoma in mice. METHODS: The antitumor effects of 2DG-PLGA-NPs were examined using hepatoma cell lines, xenograft tumors, and hepatocarcinogenic and syngeneic mouse models. RESULTS: The 2DG-PLGA-NPs induced cytotoxic effects and antitumor immunity through enhanced T-cell trafficking. In addition, 2DG-PLGA-NPs induced decreased lactate production and increased interferon-γ-positive T cells in liver tumors. Human CD8+ T cells cocultured with 2DG-PLGA-NP-treated Huh7 cells showed their increased interferon-γ production and glucose uptake compared with the CD8+ T cells co-cultured with PLGA-NP-treated Huh7 cells. Chemotaxis of CD8+ T cells was suppressed by lactate and enhanced by glucose. Interferon-γ enhanced CD8+ T-cell chemotaxis in both an autocrine and paracrine manner. Notably, the 2DG-PLGA-NPs augmented chemokine (CXCL9/CXCL10) production in liver tumors via interferon-γ-Janus kinase-signal transducers and activator of transcription pathway and 5' adenosine monophosphate-activated protein kinase-mediated suppression of histone H3 lysine 27 trimethylation. These 2DG-PLGA-NPs not only amplified antitumor effects induced by sorafenib or an anti-programmed death-1 antibody, but also suppressed anti-programmed death-1-resistant tumors. CONCLUSIONS: The newly developed 2DG-PLGA-NPs showed antitumor immunity and cytotoxicity in liver tumors in mice, suggesting the potential of 2DG-PLGA-NPs for future clinical applications.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Carcinoma, Hepatocellular/drug therapy , Deoxyglucose/administration & dosage , Liver Neoplasms, Experimental/drug therapy , Liver Neoplasms/drug therapy , Animals , CD8-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/metabolism , Carcinoma, Hepatocellular/chemically induced , Carcinoma, Hepatocellular/immunology , Carcinoma, Hepatocellular/pathology , Cell Culture Techniques , Cell Line, Tumor , Coculture Techniques , Drug Resistance, Neoplasm/drug effects , Drug Resistance, Neoplasm/immunology , Drug Synergism , Humans , Immune Checkpoint Inhibitors/administration & dosage , Interferon-gamma/metabolism , Liver Neoplasms/immunology , Liver Neoplasms/pathology , Liver Neoplasms, Experimental/chemically induced , Liver Neoplasms, Experimental/immunology , Liver Neoplasms, Experimental/pathology , Male , Mice , Nanoparticle Drug Delivery System/chemistry , Polylactic Acid-Polyglycolic Acid Copolymer/chemistry , Tumor Escape/drug effects , Warburg Effect, Oncologic/drug effects , Xenograft Model Antitumor AssaysABSTRACT
BACKGROUND: Eosinophilic esophagitis (EoE) has increased rapidly and has been well characterized. However, no nationwide survey has been conducted regarding non-esophageal eosinophilic gastrointestinal disorders (non-EoE EGIDs), and they remain poorly understood. OBJECTIVE: To compare the clinical features and natural histories of non-EoE EGIDs and EoE by using the same questionnaire, for all ages. METHODS: We conducted a nationwide hospital-based survey of patients who visited hospitals from January 2013 through December 2017. We randomly selected 10,000 hospitals that perform endoscopy. We analyzed the demographics, symptoms, gastrointestinal histology, treatments, and natural histories of EoE and non-EoE EGIDs. RESULTS: A total of 2906 hospitals responded to the questionnaire. We identified 1542 patients and obtained detailed data for 786 patients, consisting of 39% EoE and 61% non-EoE EGIDs. The clinical characteristics were analyzed for patients who met the "definite" criteria that excluded comorbidities. Non-EoE EGIDs showed no gender difference, whereas EoE was male-predominant. Tissue eosinophilia was often seen in the small intestine (62%) and stomach (49%). The frequency of hypoproteinemia was high (27%) in childhood. Children also had more serious symptoms and complications than adults: restriction of daily life activity (P = .009), failure to grow/weight loss (P = .008), and surgery (P = .01). For both diseases, the most common natural history was the continuous type: 66% (95% confidence interval [CI]: 58-74) in EoE and 64% (95% CI: 55-72) in non-EoE EGIDs. CONCLUSIONS: The percentage of persistent patients with non-EoE EGIDs was almost the same as those with EoE. Complications were more frequent in children than in adults.
Subject(s)
Enteritis , Eosinophilic Esophagitis , Gastritis , Adult , Child , Eosinophilic Esophagitis/diagnosis , Eosinophilic Esophagitis/epidemiology , Eosinophils , Gastritis/diagnosis , Gastritis/epidemiology , Humans , Male , Surveys and QuestionnairesABSTRACT
An endo-acting family 3 pectate lyase (PL I) gene from Streptomyces thermocarboxydus was cloned and expressed in Escherichia coli. The deduced PL I sequence had highest similarity to a putative pectate lyase of S. coelicolor. Recombinant PL I had significantly lower specific activity, probably a result of incorrect folding, as indicated by circular dichroism spectra analysis.