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1.
BMC Biol ; 22(1): 83, 2024 Apr 12.
Article in English | MEDLINE | ID: mdl-38609948

ABSTRACT

BACKGROUND: Glioblastoma (GBM) is an aggressive brain cancer associated with poor prognosis, intrinsic heterogeneity, plasticity, and therapy resistance. In some GBMs, cell proliferation is fueled by a transcriptional regulator, repressor element-1 silencing transcription factor (REST). RESULTS: Using CRISPR/Cas9, we identified GBM cell lines dependent on REST activity. We developed new small molecule inhibitory compounds targeting small C-terminal domain phosphatase 1 (SCP1) to reduce REST protein level and transcriptional activity in glioblastoma cells. Top leads of the series like GR-28 exhibit potent cytotoxicity, reduce REST protein level, and suppress its transcriptional activity. Upon the loss of REST protein, GBM cells can potentially compensate by rewiring fatty acid metabolism, enabling continued proliferation. Combining REST inhibition with the blockade of this compensatory adaptation using long-chain acyl-CoA synthetase inhibitor Triacsin C demonstrated substantial synergetic potential without inducing hepatotoxicity. CONCLUSIONS: Our results highlight the efficacy and selectivity of targeting REST alone or in combination as a therapeutic strategy to combat high-REST GBM.


Subject(s)
Glioblastoma , Transcription Factors , Humans , Glioblastoma/drug therapy , Gene Expression Regulation , Brain
2.
J Nat Prod ; 87(4): 1230-1234, 2024 04 26.
Article in English | MEDLINE | ID: mdl-38626456

ABSTRACT

Three new cyclic heptapeptides, talaromides A-C (1-3), were isolated from cultures produced by the fungus Talaromyces siglerae (Ascomycota), isolated from an unidentified sponge. The structures, featuring an unusual proline-anthranilic moiety, were elucidated by analysis of spectroscopic data and chemical transformations, including the advanced Marfey's method and GITC derivatization. Talaromides A and B inhibited migration activity against PANC-1 human pancreatic cancer cells without significant cytotoxicity.


Subject(s)
Peptides, Cyclic , Porifera , Talaromyces , Talaromyces/chemistry , Animals , Porifera/microbiology , Humans , Molecular Structure , Peptides, Cyclic/pharmacology , Peptides, Cyclic/chemistry , Peptides, Cyclic/isolation & purification , Drug Screening Assays, Antitumor , Marine Biology , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Antineoplastic Agents/isolation & purification
3.
J Nat Prod ; 86(4): 751-758, 2023 04 28.
Article in English | MEDLINE | ID: mdl-36812487

ABSTRACT

A chemical investigation of the endophytic Streptomyces sp. HBQ95, associated with the medicinal plant Cinnamomum cassia Presl, enabled the discovery of four new piperazic acid-bearing cyclodepsipeptides, lydiamycins E-H (1-4), and one known compound (lydiamycin A). Their chemical structures, including absolute configurations, were defined by a combination of spectroscopic analyses and multiple chemical manipulations. Lydiamycins F-H (2-4) and A (5) exhibited antimetastatic activity against PANC-1 human pancreatic cancer cells without significant cytotoxicity.


Subject(s)
Cinnamomum aromaticum , Plants, Medicinal , Pyridazines , Streptomyces , Humans , Cinnamomum aromaticum/chemistry , Streptomyces/chemistry , Pyridazines/chemistry
4.
COPD ; 20(1): 153-161, 2023 12.
Article in English | MEDLINE | ID: mdl-37036446

ABSTRACT

This study aimed to evaluate the prevalence, trends, and risk factors of early chronic obstructive pulmonary disease (COPD) by using a nationally representative sample. The datasets of the Korea National Health and Nutrition Examination Survey 2010-2019 were used, where 80,860 individuals were identified; of these, 9,045 participants aged 40-49 years who underwent spirometry with no missing data were analyzed. Early COPD was defined as forced expiratory volume in 1 s /forced vital capacity ratio < the lower limit of normal (2.5th percentile) in individuals aged <50 years without a history of asthma, inhaler therapy, or persistent respiratory symptoms. The prevalence and trend of early COPD were estimated according to features such as smoking status and pack-years. Joinpoint regression analysis was used to analyze the significant annual change in the trend according to sex, smoking status, and pack-years. A complex sample multivariable-adjusted regression model was used to identify factors affecting early COPD. The estimated population size during 2010-2019 was 82,326,178. Early COPD was present in 4.5% of patients (6.5% of men and 2.3% of women). It was present in 7.7% of current smokers, followed by former and never smokers. Among smokers with ≥ 10 pack-years, early COPD was present in 8.2%, whereas it was present in 2.6% of smokers with < 10 pack-years. Joinpoint regression analyses found a recent decrease in the trend of prevalence in males who were former and current smokers. The multivariable-adjusted logistic regression model showed that being male, lower educational level, smoking status, and pack-years were factors that affected the presence of early COPD. Continued surveillance of this pre-disease condition is required, and further research are warrant.


Subject(s)
Pulmonary Disease, Chronic Obstructive , Humans , Male , Female , Nutrition Surveys , Prevalence , Risk Factors , Smoking/adverse effects , Forced Expiratory Volume , Vital Capacity , Spirometry
5.
Int J Mol Sci ; 24(20)2023 Oct 23.
Article in English | MEDLINE | ID: mdl-37895168

ABSTRACT

Nonalcoholic steatohepatitis (NASH) is an advanced stage of fatty liver disease characterized by liver damage, inflammation, and fibrosis. Although neutrophil infiltration is consistently observed in the livers of patients with NASH, the precise role of neutrophil-recruiting chemokines and infiltrating neutrophils in NASH pathogenesis remains poorly understood. Here, we aimed to elucidate the role of neutrophil infiltration in the transition from fatty liver to NASH by examining hepatic overexpression of interleukin-8 (IL8), a major chemokine responsible for neutrophil recruitment in humans. Mice fed a high-fat diet (HFD) for 3 months developed fatty liver without concurrent liver damage, inflammation, and fibrosis. Subsequent infection with an adenovirus overexpressing human IL8 for an additional 2 weeks increased IL8 levels, neutrophil infiltration, and liver injury in mice. Mechanistically, IL8-induced liver injury was associated with the upregulation of components of the NADPH oxidase 2 complex, which participate in neutrophil oxidative burst. IL8-driven neutrophil infiltration promoted macrophage aggregate formation and upregulated the expression of chemokines and inflammatory cytokines. Notably, IL8 overexpression amplified factors associated with fibrosis, including collagen deposition and hepatic stellate cell activation, in HFD-fed mice. Collectively, hepatic overexpression of human IL8 promotes neutrophil infiltration and fatty liver progression to NASH in HFD-fed mice.


Subject(s)
Non-alcoholic Fatty Liver Disease , Animals , Mice , Diet, High-Fat/adverse effects , Disease Models, Animal , Inflammation/metabolism , Interleukin-8/genetics , Interleukin-8/metabolism , Liver/metabolism , Liver Cirrhosis/genetics , Liver Cirrhosis/metabolism , Mice, Inbred C57BL , Non-alcoholic Fatty Liver Disease/genetics , Non-alcoholic Fatty Liver Disease/metabolism
6.
Emerg Infect Dis ; 28(3): 753-756, 2022 03.
Article in English | MEDLINE | ID: mdl-35202529

ABSTRACT

We conducted a nationwide retrospective cohort study to estimate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) breakthrough infection among recipients of 4 different vaccines in South Korea. Age-adjusted breakthrough infection rate per month was highest for Janssen (42.6/100,000 population), followed by AstraZeneca (21.7/100,000 population), Pfizer-BioNTech (8.5/100,000 population), and Moderna (1.8/100,000 population).


Subject(s)
COVID-19 Vaccines , COVID-19 , COVID-19/epidemiology , COVID-19/prevention & control , Humans , Republic of Korea/epidemiology , Retrospective Studies , SARS-CoV-2
7.
Metab Eng ; 73: 214-224, 2022 09.
Article in English | MEDLINE | ID: mdl-35970507

ABSTRACT

Formed by aberrant cell division, minicells possess functional metabolism despite their inability to grow and divide. Minicells exhibit not only superior stability when compared with bacterial cells but also exceptional tolerance-characteristics that are essential for a de novo bioreactor platform. Accordingly, we engineered minicells to accumulate protein, ensuring sufficient production capability. When tested with chemicals regarded as toxic against cells, the engineered minicells produced titers of C6-C10 alcohols and esters, far surpassing the corresponding production from bacterial cells. Additionally, microbial autoinducer production that is limited in expanding bacterial population was conducted in the minicells. Because bacterial population growth was nonexistent, the minicells produced autoinducers in constant amounts, which allowed precise control of the bacterial population having autoinducer-responsive gene circuits. When bacterial population growth was nonexistent, the minicells produced autoinducers in constant amounts, which allowed precise control of the bacterial population having autoinducer-based gene circuits with the minicells. This study demonstrates the potential of minicells as bioreactors suitable for products with known limitations in microbial production, thus providing new possibilities for bioreactor engineering.


Subject(s)
Bioreactors , Escherichia coli , Cell Division , Escherichia coli/metabolism
8.
Proc Natl Acad Sci U S A ; 116(51): 25974-25981, 2019 12 17.
Article in English | MEDLINE | ID: mdl-31792171

ABSTRACT

Aldehyde dehydrogenase 2 (ALDH2), a key enzyme for detoxification the ethanol metabolite acetaldehyde, is recognized as a promising therapeutic target to treat alcohol use disorders (AUDs). Disulfiram, a potent ALDH2 inhibitor, is an approved drug for the treatment of AUD but has clinical limitations due to its side effects. This study aims to elucidate the relative contribution of different organs in acetaldehyde clearance through ALDH2 by using global- (Aldh2-/-) and tissue-specific Aldh2-deficient mice, and to examine whether liver-specific ALDH2 inhibition can prevent alcohol-seeking behavior. Aldh2-/- mice showed markedly higher acetaldehyde concentrations than wild-type (WT) mice after acute ethanol gavage. Acetaldehyde levels in hepatocyte-specific Aldh2 knockout (Aldh2Hep-/-) mice were significantly higher than those in WT mice post gavage, but did not reach the levels observed in Aldh2-/- mice. Energy expenditure and motility were dramatically dampened in Aldh2-/- mice, but moderately decreased in Aldh2Hep-/- mice compared to controls. In the 2-bottle paradigm and the drinking-in-the-dark model, Aldh2-/- mice drank negligible volumes from ethanol-containing bottles, whereas Aldh2Hep-/- mice showed reduced alcohol preference at high but not low alcohol concentrations. Glial cell- or neuron-specific Aldh2 deficiency did not affect voluntary alcohol consumption. Finally, specific liver Aldh2 knockdown via injection of shAldh2 markedly decreased alcohol preference. In conclusion, although the liver is the major organ responsible for acetaldehyde metabolism, a cumulative effect of ALDH2 from other organs likely also contributes to systemic acetaldehyde clearance. Liver-targeted ALDH2 inhibition can decrease heavy drinking without affecting moderate drinking, providing molecular basis for hepatic ALDH2 targeting/editing for the treatment of AUD.


Subject(s)
Alcohol Drinking/metabolism , Aldehyde Dehydrogenase, Mitochondrial/drug effects , Aldehyde Dehydrogenase, Mitochondrial/genetics , Aldehyde Dehydrogenase, Mitochondrial/metabolism , Ethanol/metabolism , Liver/drug effects , Liver/metabolism , Acetaldehyde/metabolism , Alanine Transaminase/blood , Alcoholism/genetics , Alcoholism/metabolism , Animals , Chemokine CCL2/metabolism , Gene Deletion , Interferon-gamma/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Neuroglia , Neurons/metabolism , RNA, Messenger/metabolism , Transcriptome
9.
Hepatology ; 72(2): 412-429, 2020 08.
Article in English | MEDLINE | ID: mdl-31705800

ABSTRACT

BACKGROUND AND AIMS: Nonalcoholic fatty liver disease encompasses a spectrum of diseases ranging from simple steatosis to nonalcoholic steatohepatitis (NASH), cirrhosis, and liver cancer. At present, how simple steatosis progresses to NASH remains obscure and effective pharmacological therapies are lacking. Hepatic expression of C-X-C motif chemokine ligand 1 (CXCL1), a key chemokine for neutrophil infiltration (a hallmark of NASH), is highly elevated in NASH patients but not in fatty livers in obese individuals or in high-fat diet (HFD)-fed mice. The aim of this study was to test whether overexpression of CXCL1 itself in the liver can induce NASH in HFD-fed mice and to test the therapeutic potential of IL-22 in this new NASH model. APPROACH AND RESULTS: Overexpression of Cxcl1 in the liver alone promotes steatosis-to-NASH progression in HFD-fed mice by inducing neutrophil infiltration, oxidative stress, and stress kinase (such as apoptosis signal-regulating kinase 1 and p38 mitogen-activated protein kinase) activation. Myeloid cell-specific deletion of the neutrophil cytosolic factor 1 (Ncf1)/p47phox gene, which encodes a component of the NADPH oxidase 2 complex that mediates neutrophil oxidative burst, markedly reduced CXCL1-induced NASH and stress kinase activation in HFD-fed mice. Treatment with interleukin (IL)-22, a cytokine with multiple targets, ameliorated CXCL1/HFD-induced NASH or methionine-choline deficient diet-induced NASH in mice. Mechanistically, IL-22 blocked hepatic oxidative stress and its associated stress kinases via the induction of metallothionein, one of the most potent antioxidant proteins. Moreover, although it does not target immune cells, IL-22 treatment attenuated the inflammatory functions of hepatocyte-derived, mitochondrial DNA-enriched extracellular vesicles, thereby suppressing liver inflammation in NASH. CONCLUSIONS: Hepatic overexpression of CXCL1 is sufficient to drive steatosis-to-NASH progression in HFD-fed mice through neutrophil-derived reactive oxygen species and activation of stress kinases, which can be reversed by IL-22 treatment via the induction of metallothionein.


Subject(s)
Chemokine CXCL1/biosynthesis , Interleukins/therapeutic use , Liver/metabolism , Neutrophil Infiltration , Non-alcoholic Fatty Liver Disease/etiology , Non-alcoholic Fatty Liver Disease/prevention & control , Animals , Diet, High-Fat/adverse effects , Disease Models, Animal , Male , Mice , Mice, Inbred C57BL , Neutrophils , Interleukin-22
10.
Hepatology ; 72(3): 873-891, 2020 09.
Article in English | MEDLINE | ID: mdl-32463484

ABSTRACT

BACKGROUND AND AIMS: Neutrophil infiltration is a hallmark of nonalcoholic steatohepatitis (NASH), but how this occurs during the progression from steatosis to NASH remains obscure. Human NASH features hepatic neutrophil infiltration and up-regulation of major neutrophil-recruiting chemokines (e.g., chemokine [C-X-C motif] ligand 1 [CXCL1] and interleukin [IL]-8). However, mice fed a high-fat diet (HFD) only develop fatty liver without significant neutrophil infiltration or elevation of chemokines. The aim of this study was to determine why mice are resistant to NASH development and the involvement of p38 mitogen-activated protein kinase (p38) activated by neutrophil-derived oxidative stress in the pathogenesis of NASH. APPROACH AND RESULTS: Inflamed human hepatocytes attracted neutrophils more effectively than inflamed mouse hepatocytes because of the greater induction of CXCL1 and IL-8 in human hepatocytes. Hepatic overexpression of Cxcl1 and/or IL-8 promoted steatosis-to-NASH progression in HFD-fed mice by inducing liver inflammation, injury, and p38 activation. Pharmacological inhibition of p38α/ß or hepatocyte-specific deletion of p38a (a predominant form in the liver) attenuated liver injury and fibrosis in the HFD+Cxcl1 -induced NASH model that is associated with strong hepatic p38α activation. In contrast, hepatocyte-specific deletion of p38a in HFD-induced fatty liver where p38α activation is relatively weak exacerbated steatosis and liver injury. Mechanistically, weak p38α activation in fatty liver up-regulated the genes involved in fatty acid ß-oxidation through peroxisome proliferator-activated receptor alpha phosphorylation, thereby reducing steatosis. Conversely, strong p38α activation in NASH promoted caspase-3 cleavage, CCAAT-enhancer-binding proteins homologous protein expression, and B cell lymphoma 2 phosphorylation, thereby exacerbating hepatocyte death. CONCLUSIONS: Genetic ablation of hepatic p38a increases simple steatosis but ameliorates oxidative stress-driven NASH, indicating that p38α plays distinct roles depending on the disease stages, which may set the stage for investigating p38α as a therapeutic target for the treatment of NASH.


Subject(s)
Fatty Liver , Hepatocytes/immunology , Mitogen-Activated Protein Kinase 14/metabolism , Non-alcoholic Fatty Liver Disease , Animals , Chemokine CXCL1/immunology , Diet, High-Fat , Disease Models, Animal , Drug Discovery , Fatty Liver/immunology , Fatty Liver/metabolism , Gene Deletion , Humans , Interleukin-8/immunology , Mice , Neutrophil Infiltration/immunology , Non-alcoholic Fatty Liver Disease/immunology , Non-alcoholic Fatty Liver Disease/metabolism , Oxidative Stress , Severity of Illness Index
11.
Hepatology ; 70(4): 1150-1167, 2019 10.
Article in English | MEDLINE | ID: mdl-30964207

ABSTRACT

Nonalcoholic fatty liver disease (NAFLD) represents a spectrum of diseases ranging from simple steatosis to more severe forms of liver injury including nonalcoholic steatohepatitis (NASH), fibrosis, and hepatocellular carcinoma (HCC). In humans, only 20%-40% of patients with fatty liver progress to NASH, and mice fed a high-fat diet (HFD) develop fatty liver but are resistant to NASH development. To understand how simple steatosis progresses to NASH, we examined hepatic expression of anti-inflammatory microRNA-223 (miR-223) and found that this miRNA was highly elevated in hepatocytes in HFD-fed mice and in human NASH samples. Genetic deletion of miR-223 induced a full spectrum of NAFLD in long-term HFD-fed mice including steatosis, inflammation, fibrosis, and HCC. Furthermore, microarray analyses revealed that, compared to wild-type mice, HFD-fed miR-223 knockout (miR-223KO) mice had greater hepatic expression of many inflammatory genes and cancer-related genes, including (C-X-C motif) chemokine 10 (Cxcl10) and transcriptional coactivator with PDZ-binding motif (Taz), two well-known factors that promote NASH development. In vitro experiments demonstrated that Cxcl10 and Taz are two downstream targets of miR-223 and that overexpression of miR-223 reduced their expression in cultured hepatocytes. Hepatic levels of miR-223, CXCL10, and TAZ mRNA were elevated in human NASH samples, which positively correlated with hepatic levels of several miR-223 targeted genes as well as several proinflammatory, cancer-related, and fibrogenic genes. Conclusion: HFD-fed miR-223KO mice develop a full spectrum of NAFLD, representing a clinically relevant mouse NAFLD model; miR-223 plays a key role in controlling steatosis-to-NASH progression by inhibiting hepatic Cxcl10 and Taz expression and may be a therapeutic target for the treatment of NASH.


Subject(s)
Carcinoma, Hepatocellular/pathology , Gene Expression Regulation , Liver Neoplasms/pathology , MicroRNAs/genetics , Non-alcoholic Fatty Liver Disease/genetics , Non-alcoholic Fatty Liver Disease/pathology , Acyltransferases , Animals , Biopsy, Needle , Carcinogenesis/genetics , Carcinoma, Hepatocellular/genetics , Diet, High-Fat , Disease Models, Animal , Disease Progression , Hepatocytes/cytology , Hepatocytes/pathology , Humans , Immunohistochemistry , Liver Neoplasms/genetics , Male , Mice, Inbred C57BL , Mice, Knockout , Microarray Analysis , Oncogenes/genetics , Random Allocation , Reference Values , Sensitivity and Specificity , Transcription Factors/genetics , Up-Regulation
12.
Hepatology ; 69(5): 1965-1982, 2019 05.
Article in English | MEDLINE | ID: mdl-30681731

ABSTRACT

Adipocyte death occurs under various physiopathological conditions, including obesity and alcohol drinking, and can trigger organ damage particularly in the liver, but the underlying mechanisms remain obscure. To explore these mechanisms, we developed a mouse model of inducible adipocyte death by overexpressing the human CD59 (hCD59) on adipocytes (adipocyte-specific hCD59 transgenic mice). Injection of these mice with intermedilysin (ILY), which rapidly lyses hCD59 expressing cells exclusively by binding to the hCD59 but not mouse CD59, resulted in the acute selective death of adipocytes, adipose macrophage infiltration, and elevation of serum free fatty acid (FFA) levels. ILY injection also resulted in the secondary damage to multiple organs with the strongest injury observed in the liver, with inflammation and hepatic macrophage activation. Mechanistically, acute adipocyte death elevated epinephrine and norepinephrine levels and activated lipolysis pathways in adipose tissue in a chemokine (C-C motif) receptor 2-positive (CCR2+ ) macrophage-dependent manner, which was followed by FFA release and lipotoxicity in the liver. Additionally, acute adipocyte death caused hepatic CCR2+ macrophage activation and infiltration, further exacerbating liver injury. Conclusion: Adipocyte death predominantly induces liver injury and inflammation, which is probably due to the superior sensitivity of hepatocytes to lipotoxicity and the abundance of macrophages in the liver.


Subject(s)
Adipocytes/physiology , Adipose Tissue/enzymology , Liver Diseases/etiology , Macrophages/physiology , Receptors, CCR2/metabolism , Animals , Bacteriocins , Cell Death , Disease Models, Animal , Epinephrine/blood , Fatty Acids, Nonesterified/blood , Female , Inflammation/etiology , Isoproterenol , Lipolysis , Liver Diseases/blood , Male , Mice, Transgenic , Norepinephrine/blood , Receptors, CCR2/genetics
13.
Gut ; 68(7): 1311-1322, 2019 07.
Article in English | MEDLINE | ID: mdl-30121625

ABSTRACT

OBJECTIVE: Aldehyde dehydrogenase 2 (ALDH2), a key enzyme to detoxify acetaldehyde in the liver, exists in both active and inactive forms in humans. Individuals with inactive ALDH2 accumulate acetaldehyde after alcohol consumption. However, how acetaldehyde affects T-cell hepatitis remains unknown. DESIGN: Wild-type (WT) and Aldh2 knockout (Aldh2-/-) mice were subjected to chronic ethanol feeding and concanavalin A (ConA)-induced T-cell hepatitis. Effects of acetaldehyde on T-cell glucose metabolism were investigated in vitro. Human subjects were recruited for binge drinking and plasma cortisol and corticosterone measurement. RESULTS: Ethanol feeding exacerbated ConA-induced hepatitis in WT mice but surprisingly attenuated it in Aldh2-/- mice despite higher acetaldehyde levels in Aldh2-/- mice. Elevation of serum cytokines and their downstream signals in the liver post-ConA injection was attenuated in ethanol-fed Aldh2-/- mice compared to WT mice. In vitro exposure to acetaldehyde inhibited ConA-induced production of several cytokines without affecting their mRNAs in mouse splenocytes. Acetaldehyde also attenuated interferon-γ production in phytohaemagglutinin-stimulated human peripheral lymphocytes. Mechanistically, acetaldehyde interfered with glucose metabolism in T cells by inhibiting aerobic glycolysis-related signal pathways. Finally, compared to WT mice, ethanol-fed Aldh2-/- mice had higher levels of serum corticosterone, a well-known factor that inhibits aerobic glycolysis. Blockade of corticosterone partially restored ConA-mediated hepatitis in ethanol-fed Aldh2-/- mice. Acute alcohol drinking elevated plasma cortisol and corticosterone levels in human subjects with higher levels in those with inactive ALDH2 than those with active ALDH2. CONCLUSIONS: ALDH2 deficiency is associated with elevated acetaldehyde and glucocorticoids post-alcohol consumption, thereby inhibiting T-cell activation and hepatitis.


Subject(s)
Aldehyde Dehydrogenase, Mitochondrial/physiology , Binge Drinking/metabolism , Glucose/metabolism , Hepatitis/metabolism , Hepatitis/prevention & control , T-Lymphocytes/physiology , Animals , Binge Drinking/pathology , Concanavalin A , Corticosterone/blood , Disease Models, Animal , Ethanol , Hepatitis/etiology , Humans , Hydrocortisone/blood , Mice
14.
J Hepatol ; 71(5): 1000-1011, 2019 11.
Article in English | MEDLINE | ID: mdl-31279903

ABSTRACT

BACKGROUND & AIMS: Excessive alcohol consumption is one of the major causes of hepatocellular carcinoma (HCC). Approximately 30-40% of the Asian population are deficient for aldehyde dehydrogenase 2 (ALDH2), a key enzyme that detoxifies the ethanol metabolite acetaldehyde. However, how ALDH2 deficiency affects alcohol-related HCC remains unclear. METHODS: ALDH2 polymorphisms were studied in 646 patients with viral hepatitis B (HBV) infection, who did or did not drink alcohol. A new model of HCC induced by chronic carbon tetrachloride (CCl4) and alcohol administration was developed and studied in 3 lines of Aldh2-deficient mice: including Aldh2 global knockout (KO) mice, Aldh2*1/*2 knock-in mutant mice, and liver-specific Aldh2 KO mice. RESULTS: We demonstrated that ALDH2 deficiency was not associated with liver disease progression but was associated with an increased risk of HCC development in cirrhotic patients with HBV who consumed excessive alcohol. The mechanisms underlying HCC development associated with cirrhosis and alcohol consumption were studied in Aldh2-deficient mice. We found that all 3 lines of Aldh2-deficient mice were more susceptible to CCl4 plus alcohol-associated liver fibrosis and HCC development. Furthermore, our results from in vivo and in vitro mechanistic studies revealed that after CCl4 plus ethanol exposure, Aldh2-deficient hepatocytes produced a large amount of harmful oxidized mitochondrial DNA via extracellular vesicles, which were then transferred into neighboring HCC cells and together with acetaldehyde activated multiple oncogenic pathways (JNK, STAT3, BCL-2, and TAZ), thereby promoting HCC. CONCLUSIONS: ALDH2 deficiency is associated with an increased risk of alcohol-related HCC development from fibrosis in patients and in mice. Mechanistic studies reveal a novel mechanism that Aldh2-deficient hepatocytes promote alcohol-associated HCC by transferring harmful oxidized mitochondrial DNA-enriched extracellular vesicles into HCC and subsequently activating multiple oncogenic pathways in HCC. LAY SUMMARY: Alcoholics with an ALDH2 polymorphism have an increased risk of digestive tract cancer development, however, the link between ALDH2 deficiency and hepatocellular carcinoma (HCC) development has not been well established. In this study, we show that ALDH2 deficiency exacerbates alcohol-associated HCC development both in patients and mouse models. Mechanistic studies revealed that after chronic alcohol exposure, Aldh2-deficient hepatocytes produce a large amount of harmful oxidized mitochondrial DNA via extracellular vesicles, which can be delivered into neighboring HCC cells and subsequently activate multiple oncogenic pathways, promoting HCC.


Subject(s)
Alcohol Drinking/adverse effects , Alcoholism/complications , Aldehyde Dehydrogenase, Mitochondrial/deficiency , Aldehyde Dehydrogenase, Mitochondrial/genetics , Carcinogenesis/genetics , Carcinoma, Hepatocellular/chemically induced , DNA, Mitochondrial/metabolism , Extracellular Vesicles/metabolism , Hepatitis B, Chronic/complications , Liver Cirrhosis/complications , Liver Neoplasms/chemically induced , Adult , Animals , Carbon Tetrachloride/administration & dosage , Carcinogenesis/metabolism , Cohort Studies , Disease Models, Animal , Female , Hepatitis B virus , Hepatitis B, Chronic/virology , Hepatocytes/metabolism , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Middle Aged , Polymorphism, Genetic
15.
Bioprocess Biosyst Eng ; 42(7): 1195-1204, 2019 Jul.
Article in English | MEDLINE | ID: mdl-30944996

ABSTRACT

The shortcut biological nitrogen removal (SBNR) process requires less aeration and external carbon due to the oxidization of ammonia into nitrite and its direct denitrification to nitrogen gas during the biological nitrogen removal process. However, this process produces a poor effluent containing NH4+, since the system has to maintain a high free ammonia (FA, NH3) concentration. To overcome this drawback, in this study, the solid retention time (SRT) and the dissolved oxygen (DO) concentration were controlled to achieve both a high ammonia removal rate and nitrite accumulation in the sequencing batch reactor (SBR) process, which can remove nitrogen from wastewater to the desired concentration and provide high free ammonia inhibition and continuous shock loading. When sufficient DO was supplied, nitrite did not accumulate with a 20-day SRT, but the wash-out of nitrite oxidizers in a shorter SRT resulted in a high nitrite accumulation. When DO acted as a limitation, nitrite accumulated at all SRTs. This indicates that nitrite accumulation is more highly influenced by SRT and DO concentration than by FA inhibition. Also, as nitrite accumulated over a 10-day SRT regardless of DO concentration, the accumulation was more highly influenced by SRT than by DO concentration.


Subject(s)
Bioreactors , Denitrification , Nitrogen/metabolism , Wastewater/microbiology , Water Microbiology , Ammonia/metabolism , Nitrites/metabolism
16.
Hepatology ; 66(1): 220-234, 2017 07.
Article in English | MEDLINE | ID: mdl-28295449

ABSTRACT

Acetaminophen (APAP) overdose is a leading cause of acute liver failure worldwide, in which mitochondrial DNA (mtDNA) released by damaged hepatocytes activates neutrophils through binding of Toll-like receptor 9 (TLR9), further aggravating liver injury. Here, we demonstrated that mtDNA/TLR9 also activates a negative feedback pathway through induction of microRNA-223 (miR-223) to limit neutrophil overactivation and liver injury. After injection of APAP in mice, levels of miR-223, the most abundant miRNAs in neutrophils, were highly elevated in neutrophils. Disruption of the miR-223 gene exacerbated APAP-induced hepatic neutrophil infiltration, oxidative stress, and injury and enhanced TLR9 ligand-mediated activation of proinflammatory mediators in neutrophils. An additional deletion of the intercellular adhesion molecule 1 (ICAM-1) gene ameliorated APAP-induced neutrophil infiltration and liver injury in miR-223 knockout mice. In vitro experiments revealed that miR-223-deficient neutrophils were more susceptible to TLR9 agonist-mediated induction of proinflammatory mediators and nuclear factor kappa B (NF-κB) signaling, whereas overexpression of miR-223 attenuated these effects in neutrophils. Moreover, inhibition of TLR9 signaling by either treatment with a TLR9 inhibitor or by disruption of TLR9 gene partially, but significantly, suppressed miR-223 expression in neutrophils post-APAP injection. In contrast, activation of TLR9 up-regulated miR-223 expression in neutrophils in vivo and in vitro. Mechanistically, activation of TLR9 up-regulated miR-223 by enhancing NF-κB binding on miR-223 promoter, whereas miR-223 attenuated TLR9/NF-κB-mediated inflammation by targeting IκB kinase α expression. Collectively, up-regulation of miR-223 plays a key role in terminating the acute neutrophilic response and is a therapeutic target for treatment of APAP-induced liver failure. (Hepatology 2017;66:220-234).


Subject(s)
Acetaminophen/toxicity , DNA, Mitochondrial/metabolism , Hepatocytes/drug effects , Liver Failure, Acute/metabolism , MicroRNAs/genetics , Toll-Like Receptor 9/metabolism , Acetaminophen/pharmacology , Animals , Cells, Cultured , Disease Models, Animal , Female , Hepatocytes/cytology , Liver Failure, Acute/pathology , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Neutrophils/cytology , Random Allocation , Reference Values , Signal Transduction , Up-Regulation
17.
J Air Waste Manag Assoc ; 65(10): 1256-60, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26252193

ABSTRACT

UNLABELLED: Environmental problems and climate change arising from waste incineration are taken quite seriously in the world. In Korea, the waste disposal methods are largely classified into landfill, incineration, recycling, etc. and the amount of incinerated waste has risen by 24.5% from 2002. In the analysis of CO2emissions estimations of waste incinerators fossil carbon content are main factor by the IPCC. FCF differs depending on the characteristics of waste in each country, and a wide range of default values are proposed by the IPCC. This study conducted research on the existing classifications of the IPCC and Korean waste classification systems based on FCF for accurate greenhouse gas emissions estimation of waste incineration. The characteristics possible for sorting were classified according to FCF and form. The characteristics sorted according to fossil carbon fraction were paper, textiles, rubber, and leather. Paper was classified into pure paper and processed paper; textiles were classified into cotton and synthetic fibers; and rubber and leather were classified into artificial and natural. The analysis of FCF was implemented by collecting representative samples from each classification group, by applying the 14C method, and using AMS equipment. And the analysis values were compared with the default values proposed by the IPCC. In this study of garden and park waste and plastics, the differences were within the range of the IPCC default values or the differences were negligible. However, coated paper, synthetic textiles, natural rubber, synthetic rubber, artificial leather, and other wastes showed differences of over 10% in FCF content. IPCC is comprised of largely 9 types of qualitative classifications, in emissions estimation a great difference can occur from the combined characteristics according with the existing IPCC classification system by using the minutely classified waste characteristics as in this study. IMPLICATIONS: Fossil carbon fraction (FCF) differs depending on the characteristics of waste in each country; and a wide range of default values are proposed by the IPCC. This study conducted research on the existing classifications of the IPCC and Korean waste classification systems based on FCF for accurate greenhouse gas emissions estimation of waste incineration.


Subject(s)
Carbon/analysis , Environmental Monitoring/methods , Fossil Fuels/analysis , Incineration , Solid Waste/analysis , Fossil Fuels/classification , Fossils , Republic of Korea , Solid Waste/classification , Waste Management
18.
Environ Technol ; 36(5-8): 1035-43, 2015.
Article in English | MEDLINE | ID: mdl-25287910

ABSTRACT

A two-stage biological aerated/anoxic filter (BAF) system for denitrification-nitrification was developed to increase nitrogen removal in the treatment of municipal wastewater with low carbon:nitrogen (C/N) ratio [Formula: see text]. This system exhibited a high denitrification efficiency (67%), despite the low C/N ratio, and the ratio of reduced nitrate to consumed organic compounds was greater than the theoretical value due to the minimization of the conversion of organic carbon to biomass growth, the maintenance of low levels of dissolved oxygen in recycled water, and the maximization of use of organic carbon biosorbed inside biomass in the denitrification BAF. The maximum rate of nitrogen removal was achieved at a recycle ratio of 170%, and the headloss in two BAFs was maintained after a 24-h backwash. Biological nitrogen removal in a two-stage BAF system was possible in a short hydraulic retention time (1.2 h) because the maximum reaction rates of nitrifiers and denitrifiers in each column were achieved.


Subject(s)
Denitrification , Nitrification , Nitrogen/isolation & purification , Water Purification , Filtration , Organic Chemicals , Oxygen
19.
Biomacromolecules ; 15(6): 2180-7, 2014 Jun 09.
Article in English | MEDLINE | ID: mdl-24805903

ABSTRACT

Poly(ethylene glycol)-poly(l-alanine) diblock copolymer (PEG-L-PA; molecular weight of each block of 1000-1080 Da) aqueous solutions undergo sol-to-gel transition in a 3.0-8.0 wt % concentration range as the temperature increases. By incorporating the polystyrene microspheres with different functional groups with a size of 100-800 µm in in situ formed PEG-L-PA thermogels, the differentiation of tonsil-tissue-derived mesenchymal stem cells (TMSCs) was investigated. The mRNA expression and immunohistochemical assays suggested that the TMSCs preferentially undergo adipogenesis in the ammonium (-NH3(+))- or thiol (-SH)-functionalized microsphere incorporated thermogels; chondrogenesis in the thiol-, phosphate (PO3(2-))-, or carboxylate (-COO(-))-functionalized microsphere incorporated thermogels; and osteogenesis in the phosphate-, carboxylate-functionalized, or neat polystyrene microsphere incorporated thermogels. This paper provides a new TMSC 3D culture system of a sol-gel reversible matrix and suggests that the surface-functional groups of microspheres in the thermogel can control the preferential differentiation of stem cells into specific cell types during the 3D culture.


Subject(s)
Cell Differentiation/drug effects , Mesenchymal Stem Cells/drug effects , Microspheres , Palatine Tonsil/drug effects , Peptides/pharmacology , Polyethylene Glycols/pharmacology , Cell Culture Techniques/methods , Cell Differentiation/physiology , Cells, Cultured , Gels , Humans , Mesenchymal Stem Cells/physiology , Palatine Tonsil/cytology , Palatine Tonsil/physiology , Peptides/chemistry , Polyethylene Glycols/chemistry , Surface Properties/drug effects
20.
Chem Pharm Bull (Tokyo) ; 62(4): 328-35, 2014.
Article in English | MEDLINE | ID: mdl-24695342

ABSTRACT

In this study, green tea compounds (flavonoids, alkaloids, and phenolic acids) were analyzed in green tea-containing dentifrices, and their stability at different pH levels was evaluated. The compounds were separated under 0.01% phosphoric acid-acetonitrile gradient conditions and detected by photodiode array detector at 210, 280, 300, 335 nm. Column temperature was set at 20°C based on the results of screening various temperatures. Each compound showed good linearity at optimized wavelength as well as showing good precision and accuracy in dentifrices. Using this method, the stability of compounds was investigated in pH 4, 7, 8, and 10 solutions for 96 h, and in pH 7 and pH 10 solutions for 6 months. The green tea compounds were more stable at low pH levels; purine alkaloids were more stable than flavonoids. In particular, gallocatechin (GC), epigallocatechin (EGC), epigallocatechin gallate (EGCG), gallocatechin gallate (GCG), and myricetin almost disappeared in pH 10 solutions after 96 h. In dentifrices, the compounds were gradually decreased until 6 months in both pH types, while gallic acid was increased because of production of galloyl ester of other green tea compounds. Therefore, it is beneficial to adjust to as low a pH as possible when produce green tea-containing dentifrices.


Subject(s)
Chromatography, Liquid/methods , Dentifrices/chemistry , Tea/chemistry , Catechin/analogs & derivatives , Catechin/chemistry , Dentifrices/analysis , Flavonoids/chemistry , Hydrogen-Ion Concentration , Temperature , Toothpastes/analysis , Toothpastes/chemistry
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