Clinical Impacts of Urinary Neutrophil Gelatinase-Associated Lipocalin in Patients With Chronic Kidney Disease Undergoing Percutaneous Coronary Intervention.

BACKGROUND: Chronic kidney disease (CKD) is associated with poor prognosis in patients undergoing percutaneous coronary intervention (PCI). Urinary neutrophil gelatinase-associated lipocalin (NGAL) is a biomarker for renal injury. However, the association between urinary NGAL concentrations and renal and cardiovascular events in patients with CKD undergoing PCI has not been elucidated. This study investigated the clinical impact of urinary NGAL concentrations on renal and cardiovascular outcomes in patients with non-dialysis CKD undergoing PCI. METHODS AND RESULTS: We enrolled 124 patients with non-dialysis CKD (estimated glomerular filtration rate <60 mL/min/1.73 m2) undergoing elective PCI. Patients were divided into low and high NGAL groups based on the median urinary NGAL concentration measured the day before PCI. Patients were monitored for renal and cardiovascular events during the 2-year follow-up period. Kaplan-Meier analyses showed that the incidence of renal and cardiovascular events was higher in the high than low NGAL group (log-rank P<0.001 and P=0.032, respectively). Multivariate Cox proportional hazards analyses revealed that urinary NGAL was an independent risk factor for renal (hazard ratio [HR] 4.790; 95% confidence interval [CI] 1.537-14.924; P=0.007) and cardiovascular (HR 2.938; 95% CI 1.034-8.347; P=0.043) events. CONCLUSIONS: Urinary NGAL could be a novel and informative biomarker for predicting subsequent renal and cardiovascular events in patients with CKD undergoing elective PCI.

Prognostic impact of polypharmacy and discharge medications in octogenarians and nonagenarian patients with acute heart failure.

With the increasing frequency of heart failure (HF) in elderly patients, polypharmacy has become a major concern owing to its adverse outcomes. However, reports on the clinical impact of polypharmacy and discharge medications in hospitalized super-aged patients with acute HF are rare. Data from 682 patients aged 80 years or older, hospitalized for treating acute HF, were analyzed. We recorded the number of medications at discharge and classified them into three groups: HF, non-HF cardiovascular, and non-cardiovascular medications. We investigated the correlation of polypharmacy, defined as daily administration of 10 or more medications at discharge, and the use of discharge medications with post-discharge prognosis. Polypharmacy was recorded in 24.3% of enrolled patients. Polypharmacy was not an independent predictor of all-cause mortality, the incidence of cardiac-related death, or HF-associated rehospitalization; however, the number of non-cardiovascular medications, multiple usage of potentially inappropriate medications, use of mineralocorticoid receptor antagonists, and doses of loop diuretics were associated with poor prognosis. Polypharmacy was significantly associated with higher mortality in patients with Barthel index ≥ 60 at discharge; hence, physical function at discharge was useful for the stratification of prognostic impacts of polypharmacy. The current study demonstrated that polypharmacy was not essentially associated with poor prognosis in super-aged patients with acute HF. Appropriate medications that consider the patient's physical function, rather than polypharmacy itself, are important for the management of HF.

Long-term outcomes of percutaneous revascularization for internal mammary artery-left anterior descending artery bypass failure.

Despite the excellent long-term results of internal mammary artery (IMA)-left anterior descending (LAD) bypass, percutaneous revascularization of IMA is sometimes required for IMA-LAD bypass failure. However, its clinical outcomes have not been fully elucidated. The aim of this study was to investigate the long-term clinical outcomes, including target lesion revascularization (TLR) following contemporary percutaneous revascularization of failed IMA bypass graft. We examined data of 59 patients who had undergone percutaneous revascularization of IMA due to IMA-LAD bypass failure at nine hospitals. Patients with IMA graft used for Y-composite graft or sequential bypass graft were excluded. The incidence of TLR was primarily examined, whereas other clinical outcomes including cardiac death, myocardial infarction, and target vessel revascularization were also evaluated. Mean age of the enrolled patients was 67.4 ± 11.3 years, and 74.6% were men. Forty patients (67.8%) had anastomotic lesions, and 17 (28.8%) underwent revascularization within three months after bypass surgery. Procedural success was achieved in 55 (93.2%) patients. Stent implantation was performed in 13 patients (22.0%). During a median follow-up of 1401 days (interquartile range, 282-2521 days), TLR was required in six patients (8.5% at 1, 3, and 5 years). Patients who underwent percutaneous revascularization within 3 months after surgery tended to have a higher incidence of TLR. Clinical outcomes of IMA revascularization for IMA-LAD bypass failure were acceptable.

A new fluorescent sensor mitoferrofluor indicates the presence of chelatable iron in polarized and depolarized mitochondria.

Mitochondrial chelatable iron contributes to the severity of several injury processes, including ischemia/reperfusion, oxidative stress, and drug toxicity. However, methods to measure this species in living cells are lacking. To measure mitochondrial chelatable iron in living cells, here we synthesized a new fluorescent indicator, mitoferrofluor (MFF). We designed cationic MFF to accumulate electrophoretically in polarized mitochondria, where a reactive group then forms covalent adducts with mitochondrial proteins to retain MFF even after subsequent depolarization. We also show in cell-free medium that Fe2+ (and Cu2+), but not Fe3+, Ca2+, or other biologically relevant divalent cations, strongly quenched MFF fluorescence. Using confocal microscopy, we demonstrate in hepatocytes that red MFF fluorescence colocalized with the green fluorescence of the mitochondrial membrane potential (ΔΨm) indicator, rhodamine 123 (Rh123), indicating selective accumulation into the mitochondria. Unlike Rh123, mitochondria retained MFF after ΔΨm collapse. Furthermore, intracellular delivery of iron with membrane-permeant Fe3+/8-hydroxyquinoline (FeHQ) quenched MFF fluorescence by ∼80% in hepatocytes and other cell lines, which was substantially restored by the membrane-permeant transition metal chelator pyridoxal isonicotinoyl hydrazone. We also show FeHQ quenched the fluorescence of cytosolically coloaded calcein, another Fe2+ indicator, confirming that Fe3+ in FeHQ undergoes intracellular reduction to Fe2+. Finally, MFF fluorescence did not change after addition of the calcium mobilizer thapsigargin, which shows MFF is insensitive to physiologically relevant increases of mitochondrial Ca2+. In conclusion, the new sensor reagent MFF fluorescence is an indicator of mitochondrial chelatable Fe2+ in normal hepatocytes with polarized mitochondria as well as in cells undergoing loss of ΔΨm.

Improved Renal Function After Percutaneous Coronary Intervention in Non-Dialysis Patients With Acute Coronary Syndrome and Advanced Renal Dysfunction.

BACKGROUND: The deterioration of renal function is a strong prognostic predictor in patients with coronary artery disease. Although percutaneous coronary intervention (PCI) has sometimes resulted in improved renal function (IRF) in acute coronary syndrome (ACS) patients, its clinical implications have not been fully elucidated. This study aimed to investigate the prevalence and predictors of IRF after PCI and its relationship with long-term renal outcomes. METHODS: In this retrospective observational cohort study, we examined data from 177 ACS patients with non-dialysis advanced renal dysfunction (estimated glomerular filtration rate [eGFR] < 30 mL/min/1.73 m2) who underwent PCI. Patients with and without IRF were compared in terms of baseline demographic, clinical, and procedural characteristics and renal outcomes. IRF was defined as a 20% increase in eGFR from baseline at 7 or 30 days after the index PCI. RESULTS: IRF was observed in 66 (37.3%) patients. ST-elevation myocardial infarction and shock during PCI were independent predictors of IRF. Patients were followed up for a median of 695 days. Kaplan-Meier analyses demonstrated that patients with IRF had the lower incidence of initiation of permanent dialysis than those without IRF (Log-rank P = 0.015). CONCLUSIONS: IRF was relatively common in non-dialysis patients with ACS and advanced renal dysfunction who underwent PCI. ST-elevation myocardial infarction and shock, which may be indicative of hemodynamic instability during PCI, were independent predictors of IRF. Further, IRF was associated with favorable renal outcomes. Hemodynamic stabilization may be important for improving the short-term and long-term renal outcomes of high-risk patients.

Clinical outcomes after percutaneous coronary intervention in non-dialysis patients with acute coronary syndrome and advanced renal dysfunction.

BACKGROUND: Data about the clinical outcomes of ACS patients with advanced renal dysfunction (estimated glomerular filtration rate < 30 mL/min/1.73 m2) following percutaneous coronary intervention (PCI) are limited. METHODS: We examined the data obtained from 194 ACS patients with non-dialysis advanced renal dysfunction who underwent PCI at five hospitals. The primary composite endpoint was the incidence of major adverse cardiac and cerebrovascular events (MACCE: all-cause death, myocardial infarction, and ischemic stroke). RESULTS: Eighty patients (41.2%) were diagnosed with ST-elevation myocardial infarction (STEMI), and 117 patients (58.8%) with non-ST-elevation ACS (NSTE-ACS). Overall patients were followed for a median of 657.5 days. Cumulative incidence of MACCE at median follow-up was 32.3% (45.4% for STEMI and 23.4% for NSTE-ACS). Kaplan-Meier analysis demonstrated that patients in the STEMI group had significantly higher incidence of MACCE than those in the non-STEMI and unstable angina group (Log-rank p < 0.001). In-hospital MACCE rate was higher in the STEMI group than in the NSTE-ACS group, whereas post-discharge MACCE rate was comparable between the two groups. In the multivariate analysis, STEMI and Killip classification ≥ 2 were associated with in-hospital MACCE. On the other hand, body mass index and serum albumin at admission were independent predictors of post-discharge MACCE. CONCLUSIONS: Short- and long-term prognoses following PCI in non-dialysis patients with ACS and advanced renal dysfunction is still unfavorable. STEMI and Killip classification ≥ 2 were independent predictors for in-hospital MACCE, and body mass index and serum albumin were for post-discharge MACCE.

Pyrenocine A induces monopolar spindle formation and suppresses proliferation of cancer cells.

Pyrenocine A, a phytotoxin, was found to exhibit cytotoxicity against cancer cells with an IC50 value of 2.6-12.9 µM. Live cell imaging analysis revealed that pyrenocine A arrested HeLa cells at the M phase with characteristic ring-shaped chromosomes. Furthermore, as a result of immunofluorescence staining analysis, we found that pyrenocine A resulted in the formation of monopolar spindles in HeLa cells. Monopolar spindles are known to be induced by inhibitors of the kinesin motor protein Eg5 such as monastrol and STLC. Monastrol and STLC induce monopolar spindle formation and M phase arrest via inhibition of the ATPase activity of Eg5. Interestingly, our data revealed that pyrenocine A had no effect on the ATPase activity of Eg5 in vitro, which suggested the compound induces a monopolar spindle by an unknown mechanism. Structure-activity relationship analysis indicates that the enone structure of pyrenocine A is likely to be important for its cytotoxicity. An alkyne-tagged analog of pyrenocine A was synthesized and suppressed proliferation of HeLa cells with an IC50 value of 2.3 µM. We concluded that pyrenocine A induced monopolar spindle formation by a novel mechanism other than direct inhibition of Eg5 motor activity, and the activity of pyrenocine A may suggest a new anticancer mechanism.

Aldehyde dehydrogenase-2 activation by Alda-1 decreases necrosis and fibrosis after bile duct ligation in mice.

BACKGROUND AND AIM: Liver fibrosis is a leading cause of mortality worldwide. Oxidative stress is a key component in the pathogenesis of liver fibrosis. We investigated the role of aldehyde formation resulting from lipid peroxidation in cholestatic liver injury and fibrosis. METHODS: C57Bl/6J mice underwent bile duct ligation (BDL) or sham operation. One hour after surgery and daily thereafter, animals were given Alda-1 (20 mg/kg, s.c.), an aldehyde dehydrogenase-2 activator, or equivalent volume of vehicle. Blood and livers were collected after 3 and 14 days. RESULTS: Serum alanine aminotransferase (ALT) increased from 39.8 U/L after sham operation to 537 U/L 3 days after BDL, which Alda-1 decreased to 281 U/L. Biliary infarcts with a periportal distribution developed with an area of 7.8% at 14 days after BDL versus 0% area after sham operation. Alda-1 treatment with BDL decreased biliary infarcts to 1.9%. Fibrosis detected by picrosirius red staining increased from 1.6% area in sham to 7.3% after BDL, which decreased to 3.8% with Alda-1. Alda-1 suppression of fibrosis was additionally confirmed by second harmonic generation microscopy. After BDL, collagen-I mRNA increased 12-fold compared to sham, which decreased to 6-fold after Alda-1 treatment. Smooth muscle α-actin expression in the liver, a marker of activated stellate cells, increased from 1% area in sham to 18.7% after BDL, which decreased to 5.3% with Alda-1. CD68-positive macrophages increased from 33.4 cells/field in sham to 134.5 cells/field after BDL, which decreased to 64.9 cells/field with Alda-1. Lastly, 4-hydroxynonenal adduct (4-HNE) immunofluorescence increased from 2.5% area in sham to 14.1% after BDL. Alda-1 treatment decreased 4-HNE to 2.2%. CONCLUSION: Accelerated aldehyde degradation by Alda-1 decreases BDL-induced liver necrosis, inflammation, and fibrosis, implying that aldehydes play an important role in the pathogenesis of cholestatic liver injury and fibrosis.

Necrostatin-7 suppresses RANK-NFATc1 signaling and attenuates macrophage to osteoclast differentiation.

Osteoclasts play a crucial role in osteolytic bone diseases, such as osteoporosis, rheumatoid arthritis, periodontitis, Paget's disease of bone and bone metastatic tumors. Therefore, controlling osteoclast differentiation and function has been considered a promising therapeutic strategy. Here, we show that necrostatin (Nec)-7, an inhibitor of programmed necrosis, strongly suppressed receptor activator of nuclear factor (NF)-κB ligand (RANKL)-induced osteoclastogenesis and bone resorption, without compromising macrophage colony-stimulating factor (M-CSF)-supported survival and growth of osteoclast precursor cells. Accordingly, Nec-7 significantly decreased the levels of RANKL-induced osteoclastogenic marker genes, such as cathepsin K. Mechanistically, Nec-7 neither affected MAPK nor NF-κB activation; however, it strongly inhibited the RANKL receptor (RANK) to nuclear factor of activated T cells c1 (NFATc1) signaling. Lentiviral expression of RANK in bone marrow-derived macrophages significantly restored osteoclastogenesis and NFATc1 amplification in Nec-7-treated cells. In this study, we revealed that Nec-7-sensitive pathways are crucially involved in osteoclast formation and function. Investigation of the molecular mechanism(s) through which Nec-7 inhibits RANK-NFATc1 signaling axis may lead to the development of new therapeutic strategies for bone disease.

Actin-binding protein coronin 1A controls osteoclastic bone resorption by regulating lysosomal secretion of cathepsin K.

Osteoclasts degrade bone matrix proteins via the secretion of lysosomal enzymes. However, the precise mechanisms by which lysosomal components are transported and fused to the bone-apposed plasma membrane, termed ruffled border membrane, remain elusive. Here, we identified coronin 1A as a negative regulator of exocytotic release of cathepsin K, one of the most important bone-degrading enzymes in osteoclasts. The modulation of coronin 1A expression did not alter osteoclast differentiation and extracellular acidification, but strongly affected the secretion of cathepsin K and osteoclast bone-resorption activity, suggesting the coronin 1A-mediated regulation of lysosomal trafficking and protease exocytosis. Further analyses suggested that coronin 1A prevented the lipidation-mediated sorting of the autophagy-related protein LC3 to the ruffled border and attenuated lysosome-plasma membrane fusion. In this process, the interactions between coronin 1A and actin were crucial. Collectively, our findings indicate that coronin 1A is a pivotal component that regulates lysosomal fusion and the secretion pathway in osteoclast-lineage cells and may provide a novel therapeutic target for bone diseases.

Clinical benefit of tolvaptan in patients with acute decompensated heart failure and chronic kidney disease.

Tolvaptan, a vasopressin type 2 receptor antagonist, has an aquaretic effect without affecting renal function. The effects of long-term tolvaptan administration in heart failure patients with renal dysfunction have not been clarified. Here, we assessed the clinical benefit of tolvaptan during a 6-month follow-up in acute decompensated heart failure (ADHF) patients with severe chronic kidney disease (CKD; estimated glomerular filtration rate (eGFR) <45 mL/min/1.73 m(2)). We compared 33 patients with ADHF and severe CKD who were administered tolvaptan in addition to loop diuretics (TLV group), with 36 patients with ADHF and severe CKD who were administered high-dose loop diuretics (≥40 mg) alone (LD group). Alterations in serum creatinine and eGFR levels from the time of hospital discharge to 6-month follow-up were significantly different between the groups, with those in the TLV group being more favorable. Furthermore, Kaplan-Meier analysis revealed that rehospitalization for heart failure (HF) was significantly lower in the TLV group compared with the LD group. In ADHF patients with severe CKD, tolvaptan use for 6 months reduced worsening of renal function and rehospitalization rates for HF when compared with conventional diuretic therapy. In conclusion, tolvaptan could be a safe and effective agent for long-term management of HF and CKD.

Inhibition of MMP-2-Mediated Mast Cell Invasion by NF-κB Inhibitor DHMEQ in Mast Cells.

BACKGROUND: Stimulation with antigen and IgE is known to activate NF-κB in mast cells. In the present research, we studied the role of NF-κB on cellular migration in mast cell-like RBL-2H3 cells and bone marrow-derived mast cells (BMMCs) using the NF-κB inhibitor (-)-DHMEQ. METHODS: A Matrigel invasion chamber was used to evaluate cell migration. A PCR array was used to screen the expression of 84 key genes involved in cell migration. RESULTS: (-)-DHMEQ inhibited antigen/IgE-induced NF-κB activation and expressions of its target genes such as IL-6 and TNF-α. (-)-DHMEQ was found to inhibit in vitro invasion toward the antigen without any toxicity. We then looked for NF-κB-dependent genes that would be important for mast cell invasion using the PCR array. (-)-DHMEQ was found to lower the expression of matrix metalloproteinase (MMP)-2. The MMP inhibitor GM6001 also inhibited cellular invasion toward the antigen. These effects of (-)-DHMEQ were obtained in both RBL-2H3 cells and BMMCs. CONCLUSIONS: These findings indicate that (-)-DHMEQ suppressed mast cell migration via the inhibition of NF-κB-regulated MMP-2 expression.

Compressive stress induces dephosphorylation of the myosin regulatory light chain via RhoA phosphorylation by the adenylyl cyclase/protein kinase A signaling pathway.

Mechanical stress that arises due to deformation of the extracellular matrix (ECM) either stretches or compresses cells. The cellular response to stretching has been actively studied. For example, stretching induces phosphorylation of the myosin regulatory light chain (MRLC) via the RhoA/RhoA-associated protein kinase (ROCK) pathway, resulting in increased cellular tension. In contrast, the effects of compressive stress on cellular functions are not fully resolved. The mechanisms for sensing and differentially responding to stretching and compressive stress are not known. To address these questions, we investigated whether phosphorylation levels of MRLC were affected by compressive stress. Contrary to the response in stretching cells, MRLC was dephosphorylated 5 min after cells were subjected to compressive stress. Compressive loading induced activation of myosin phosphatase mediated via the dephosphorylation of myosin phosphatase targeting subunit 1 (Thr853). Because myosin phosphatase targeting subunit 1 (Thr853) is phosphorylated only by ROCK, compressive loading may have induced inactivation of ROCK. However, GTP-bound RhoA (active form) increased in response to compressive stress. The compression-induced activation of RhoA and inactivation of its effector ROCK are contradictory. This inconsistency was due to phosphorylation of RhoA (Ser188) that reduced affinity of RhoA to ROCK. Treatment with the inhibitor of protein kinase A that phosphorylates RhoA (Ser188) induced suppression of compression-stimulated MRLC dephosphorylation. Incidentally, stretching induced phosphorylation of MRLC, but did not affect phosphorylation levels of RhoA (Ser188). Together, our results suggest that RhoA phosphorylation is an important process for MRLC dephosphorylation by compressive loading, and for distinguishing between stretching and compressing cells.

Bioactive dihydronaphthoquinone derivatives from Fusarium solani.

New dihydronaphthoquinone derivatives, karuquinone A (1), karuquinone B (2), and karuquinone C (3), were isolated from a fungal culture broth of Fusarium solani. The structures were determined by interpretation of spectroscopic data (1D/2D NMR, MS, and IR). Three known compounds, javanicin (4), 2,3-dihydro-5-hydroxy-8-methoxy-2,4-dimethylnaphtho[1,2-b]furan-6,9-dione (5), and 5-hydroxydihydrofusarubin C (6), were also isolated. The six isolated compounds were tested for cytotoxicity against three human cancer cell lines and a human umbilical vein endothelial cell (HUVEC) line. Of these, karuquinone A exhibited the strongest cytotoxic activity. Karuquinone B did not affect the proliferation of the cancer cell lines but did inhibit the proliferation of HUVEC. Additionally, we demonstrated that karuquinone A induces apoptosis in cancer cells through the generation of reactive oxygen species (ROS).

Cytotoxic alkylated hydroquinone, phenol, and cyclohexenone derivatives from Aspergillus violaceofuscus Gasperini.

New alkylated hydroquinones violaceoid A (1), violaceoid B (2), and violaceoid C (3), an alkylated phenol violaceoid D (4), and a cyclohexenoid violaceoid E (5) were isolated from a culture broth of Aspergillus violaceofuscus Gasperini isolated from moss. The structures were identified by interpretation of spectroscopic data (1D and 2D NMR, MS, and IR). Two known compounds, the cyclohexenoid 6 and eupenoxide (7), were also isolated. Compound 6 was isolated for the first time as a natural product and named violaceoid F. Isolated compounds were tested for cytotoxic activity against five human cancer cell lines and a mouse macrophage cell line. Violaceoid A was the most potent of the seven compounds against all cell lines. Violaceoid C and D exhibited cytotoxicity against the leukemia cell lines with LD50 values 5.9-8.3 µM, while violaceoid F was found to be cytotoxic against HCT116 and RAW264.7 with LD50 values of 6.4 and 6.5 µM, respectively. These results demonstrate that violaceoid derivatives are a new class of cytotoxic hydroquinones with a hydroxymethyl and a linear alkyl substituent.

Assessment of [(18)F]-fluoroacetate PET/CT as a tumor-imaging modality: preclinical study in healthy volunteers and clinical evaluation in patients with liver tumor.

OBJECTIVE: Although [(18)F]-FDG is a useful oncologic PET tracer, FDG uptake is known to be low in a certain type of hepatocellular carcinoma (HCC). [(18)F]-fluoroacetate ((18)F-FACE) is an [(18)F] fluorinated acetate, which is known to be converted into fatty acids, incorporated in membrane and is expected to be a promising oncologic PET tracer. The aim of this study was to evaluate the usefulness of (18)F-FACE as an oncologic PET tracer in preclinical study in healthy volunteers and in patients with liver tumors. METHODS: Twenty-four healthy volunteers (age 48.2 ± 12.9 years old; 15 male and 9 female) and ten patients with liver tumor (age 72.1 ± 7.0 years old; 6 male and 4 female) were included. We performed whole-body static PET/CT scan using (18)F-FACE (n = 34) and (18)F-FDG (n = 5 for volunteers, n = 8 for patients) on each day, respectively. Qualitative analysis and quantitative analysis of tumors (5 HCCs, 1 cholangiocellular carcinoma, 4 metastatic tumors from colon cancer and P-NET) were performed using SUVmax and tumor-to-normal liver ratio (TNR). RESULTS: In healthy volunteers, (18)F-FACE was metabolically stable in vivo and its biodistribution was almost similar to blood pool, basically uniformly independent of age and gender during PET scan time (up to 3 h). Normal physiological uptake of (18)F-FACE at each organ including liver (SUVmean 1.8 ± 0.2) was lower than that of blood pool (SUVmean 2.3 ± 0.3) at 1 h after injection. Chronic inflammatory uptake around femur of post-operative state of femoral osteotomy and faint uptake of benign hemangioma were observed in a case of healthy volunteer. (18)F-FACE (SUVmax 2.7 ± 0.6, TNR 1.5 ± 0.4) of liver tumors was significantly lower than those of (18)F-FDG uptake (6.5 ± 4.2, 2.6 ± 1.7, respectively). In qualitative analysis, (18)F-FDG was positive in 4 tumors (3 HCCs, 1 CCC) and negative in the other 6 tumors, while (18)F-FACE was also positive in 4 tumors which were the same tumors with positive (18)F-FDG uptake. CONCLUSIONS: Biodistribution of (18)F-FACE was appropriate for oncologic imaging. Tumor (18)F-FACE uptake was positive in four patients with HCC and CCC, but the uptake pattern was similar to (18)F-FDG. Further evaluation was needed.

Attenuation of steatohepatitis, fibrosis, and carcinogenesis in mice fed a methionine-choline deficient diet by CCAAT/enhancer-binding protein homologous protein deficiency.

BACKGROUND AND AIMS: Hepatic steatosis is a metabolic liver disease with the potential to progress to steatohepatitis, cirrhosis, and hepatocellular carcinoma (HCC). The aim of this study was to investigate the impact of CCAAT/enhancer-binding protein homologous protein (CHOP) deficiency in the development of steatosis-associated progression of HCC. METHODS: Eight-week-old wild-type (WT) and CHOP knockout (CHOP-/-) mice were fed a normal or methionine-choline-deficient (MCD) diet. Mice were sacrificed after 3 weeks, and steatosis, inflammation, apoptosis, and liver damage were assessed. We also evaluated fibrosis after 8 weeks of nutrition intervention. To explore the role of CHOP in liver carcinogenesis, 25 mg/kg of diethylnitrosamine (DEN) was injected intraperitoneally into 2-week-old mice, which were then fed the aforementioned diets from 8 to 24 weeks of age. CHOP expression in HCC patient livers was also evaluated. RESULTS: CHOP deficiency did not affect steatosis but significantly reduced apoptotic cells, inflammation scores, and serum liver enzymes. It also significantly suppressed total serum bilirubin levels, fibrotic area size, and messenger RNA expression of profibrotic cytokines. DEN-initiated carcinogenesis was promoted by the MCD diet, while CHOP deficiency significantly attenuated the total number and maximum diameter of tumors and the Ki-67 labeling index. In human livers, CHOP expression was enhanced in parallel with non-alcoholic steatohepatitis-to-HCC progression. CONCLUSIONS: CHOP deficiency attenuated apoptosis, inflammation, fibrosis, and tumorigenesis under fat-loading conditions, indicating that a therapeutic strategy targeting CHOP might be effective for fat-induced liver injury and protecting against promotion of carcinogenesis in patients with liver steatosis.

Specific inhibition of hepatitis C virus entry into host hepatocytes by fungi-derived sulochrin and its derivatives.

Hepatitis C virus (HCV) is a major causative agent of hepatocellular carcinoma. Although various classes of anti-HCV agents have been under clinical development, most of these agents target RNA replication in the HCV life cycle. To achieve a more effective multidrug treatment, the development of new, less expensive anti-HCV agents that target a different step in the HCV life cycle is needed. We prepared an in-house natural product library consisting of compounds derived from fungal strains isolated from seaweeds, mosses, and other plants. A cell-based functional screening of the library identified sulochrin as a compound that decreased HCV infectivity in a multi-round HCV infection assay. Sulochrin inhibited HCV infection in a dose-dependent manner without any apparent cytotoxicity up to 50 µM. HCV pseudoparticle and trans-complemented particle assays suggested that this compound inhibited the entry step in the HCV life cycle. Sulochrin showed anti-HCV activities to multiple HCV genotypes 1a, 1b, and 2a. Co-treatment of sulochrin with interferon or a protease inhibitor telaprevir synergistically augmented their anti-HCV effects. Derivative analysis revealed anti-HCV compounds with higher potencies (IC50<5 µM). This is the first report showing an antiviral activity of methoxybenzoate derivatives. Thus, sulochrin derivatives are anti-HCV lead compounds with a new mode of action.

Selenoneine, a novel selenium-containing compound, mediates detoxification mechanisms against methylmercury accumulation and toxicity in zebrafish embryo.

The selenium (Se)-containing antioxidant selenoneine (2-selenyl-N α,N α,N α-trimethyl-L-histidine) has recently been discovered to be the predominant form of organic Se in tuna blood. Although dietary intake of fish Se has been suggested to reduce methylmercury (MeHg) toxicity, the molecular mechanism of MeHg detoxification by Se has not yet been determined. Here, we report evidence that selenoneine accelerates the excretion and demethylation of MeHg, mediated by a selenoneine-specific transporter, organic cations/carnitine transporter-1 (OCTN1). Selenoneine was incorporated into human embryonic kidney HEK293 cells transiently overexpressing OCTN1 and zebrafish blood cells by OCTN1. The K m for selenoneine uptake was 13.0 µM in OCTN1-overexpressing HEK293 cells and 9.5 µM in zebrafish blood cells, indicating high affinity of OCTN1 for selenoneine in human and zebrafish cells. When such OCTN1-expressing cells and embryos were exposed to MeHg-cysteine (MeHgCys), MeHg accumulation was decreased and the excretion and demethylation of MeHg were enhanced by selenoneine. In addition, exosomal secretion vesicles were detected in the culture water of embryos that had been microinjected with MeHgCys, suggesting that these may be responsible for MeHg excretion and demethylation. In contrast, OCTN1-deficient embryos accumulated MeHg, and MeHg excretion and demethylation were decreased. Furthermore, Hg accumulation was decreased in OCTN1-overexpressing HEK293 cells, but not in mock vector-transfected cells, indicating that selenoneine and OCTN1 can regulate MeHg detoxification in human cells. Thus, the selenoneine-mediated OCTN1 system regulates secretory lysosomal vesicle formation and MeHg demethylation.