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1.
J Med Virol ; 95(1): e28210, 2023 01.
Article in English | MEDLINE | ID: mdl-36222204

ABSTRACT

Nucleos(t)ide analogs (NAs) cannot completely suppress the risk of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB). This study aimed to identify the risk factors for HCC development in naïve CHB patients treated with current NA. Patients receiving NA (n = 905) were recruited retrospectively from the 17 hospitals of the Japanese Red Cross Liver Study Group. All treatment-naïve patients had been receiving current NA continuously for more than 1 year until the end of the follow-up. We analyzed the accuracy of predictive risk score using the area under receiver operating characteristic curve. The albumin-bilirubin (ALBI) score was significantly improved by NA therapy (-0.171 ± 0.396; p < 0.001 at Week 48). A total of 72 (8.0%) patients developed HCC over a median follow-up of 6.2 (1.03-15.7) years. An independent predictive factor of HCC development was older age, cirrhosis, lower platelet counts at baseline and ALBI score, and alpha-fetoprotein (AFP) at 1 year after NA therapy according to multivariate analysis. The accuracy was assessed using the PAGE-B, mPAGE-B, aMAP, APA-B, and REAL-B scores that included these factors. Discrimination was generally acceptable for these models. aMAP and REAL-B demonstrated high discrimination with 0.866/0.862 and 0.833/0.859 for 3- and 5-year prediction from the status of 1 year after NA therapy, respectively. Baseline age and platelet count, as well as ALBI and AFP one year after NA, were useful for stratifying carcinogenesis risk. The aMAP and REAL-B scores were validated with high accuracy in Japanese CHB patients.


Subject(s)
Carcinoma, Hepatocellular , Hepatitis B, Chronic , Liver Neoplasms , Humans , Carcinoma, Hepatocellular/epidemiology , Carcinoma, Hepatocellular/etiology , Carcinoma, Hepatocellular/drug therapy , alpha-Fetoproteins , Liver Neoplasms/epidemiology , Liver Neoplasms/etiology , Hepatitis B, Chronic/complications , Hepatitis B, Chronic/drug therapy , Hepatitis B, Chronic/pathology , Antiviral Agents/therapeutic use , Retrospective Studies , Risk Factors , Albumins
2.
JGH Open ; 6(1): 20-28, 2022 Jan.
Article in English | MEDLINE | ID: mdl-35071784

ABSTRACT

BACKGROUND AND AIM: The pathogenic process underlying the development of hepatocellular carcinoma (HCC) is not yet clear in patients with hepatitis C virus (HCV) who have received direct-acting antiviral (DAA) therapy and achieved sustained virological response (SVR). This study validated a composite predictive model for HCC in these patients. METHODS: This study included 3058 patients in whom HCV was eradicated with DAA therapy. After DAAs recommendation for surveillance (ADRES) score, which is based on sex, FIB-4 index, and α-fetoprotein, was used as a composite predictive model for HCC development. RESULTS: The 1-, 3-, and 5-year cumulative incidence rates of HCC were 0.9, 4.5, and 15.2%, respectively. Multivariate analysis with Cox proportional hazards models showed that male sex (hazard ratio [HR], 2.646; 95% confidence interval [CI], 1.790-3.911), FIB-4 index >3.25 (HR, 2.891; 95% CI, 1.947-4.293), and α-fetoprotein >5 ng/mL (HR, 2.835; 95% CI, 1.914-4.200) are independently associated with HCC development. The incidence of HCC differed significantly by ADRES score (P < 0.001). Cox proportional hazards models showed that compared to the ADRES score 0 group, the HR for HCC development was 2.947 (95% CI, 1.367-6.354) in the ADRES score 1 group, 9.171 (95% CI, 4.339-19.380) in the ADRES score 2 group, and 20.630 (95% CI, 8.641-49.230) in the ADRES score 3 group. ADRES score had superior predictive power for HCC development compared with the FIB-4 index and α-fetoprotein according to time-dependent receiver operating characteristic analysis. CONCLUSION: The ADRES score is useful for predicting HCC development after SVR.

3.
Hepatol Commun ; 6(3): 461-472, 2022 03.
Article in English | MEDLINE | ID: mdl-34676692

ABSTRACT

The identification of patients with advanced fibrosis who do not need any further hepatocellular carcinoma (HCC) surveillance after the eradication of hepatitis C is pivotal. In this study, we developed a simple serum-based risk model that could identify patients with low-risk HCC. This was a nationwide multicenter study involving 16 Hospitals in Japan. Patients with advanced fibrosis (1,325 in a derivation cohort and 508 in a validation cohort) who achieved sustained virological responses at 24 weeks after treatment (SVR24) were enrolled. The HCC risk model at any point after SVR24 and its change were evaluated, and subsequent HCC development was analyzed. Based on the multivariable analysis, patients fulfilling all of the factors (GAF4 criteria: gamma-glutamyl transferase < 28 IU/L, alpha-fetoprotein < 4.0 ng/mL, and Fibrosis-4 Index < 4.28) were classified as low-risk and others were classified as high-risk. When patients were stratified at the SVR24, and 1 year, and 2 years after SVR24, subsequent HCC development was significantly lower in low-risk patients (0.5-1.1 per 100 person-years in the derivation cohort and 0.9-1.1 per 100 person-years in the validation cohort) than in high-risk patients at each point. HCC risk from 1 year after SVR24 decreased in patients whose risk improved from high-risk to low-risk (HCC incidence: 0.6 per 100 person-years [hazard ratio (HR) = 0.163 in the derivation cohort] and 1.3 per 100 person-years [HR = 0.239 in the validation cohort]) than in those with sustained high risk. Conclusion: The HCC risk model based on simple serum markers at any point after SVR and its change can identify patients with advanced fibrosis who are at low HCC risk, and these patients may be able to reduce HCC surveillance.


Subject(s)
Carcinoma, Hepatocellular , Hepatitis C, Chronic , Hepatitis C , Liver Neoplasms , Antiviral Agents/therapeutic use , Carcinoma, Hepatocellular/diagnosis , Hepacivirus , Hepatitis C/complications , Hepatitis C, Chronic/complications , Humans , Liver Cirrhosis/complications , Liver Neoplasms/diagnosis , Risk Assessment , Risk Factors
4.
J Med Virol ; 93(11): 6247-6256, 2021 11.
Article in English | MEDLINE | ID: mdl-34170517

ABSTRACT

The real-world virological efficacy and safety of interferon-free direct-acting antiviral (DAA) therapy with sofosbuvir (SOF) and velpatasvir (VEL) were assessed in hepatitis C virus (HCV) genotype 1- and 2-infected patients with decompensated cirrhosis. A total of 65 patients with HCV-related decompensated cirrhosis (Child-Pugh score of 7 points or more) who were treated with the SOF/VEL regimen were enrolled. The sustained virological response (SVR) rate and safety profile were analyzed. SVR was defined as undetectable serum HCV RNA at 12 weeks after the end of treatment (SVR12). The percentages of patients with undetectable HCV RNA at 4, 8, and 12 weeks after the start of therapy were 81.2% (95% confidence interval [CI], 69.5-89.9) (52/64), 98.4% (95% CI, 91.2-100.0) (60/61), and 98.5% (95% CI, 91.7-100.0) (64/65), respectively. The overall SVR rate was 92.3% (95% CI, 83.0-97.5) (60/65). Albumin-bilirubin (ALBI) scores decreased during and after treatment (p < 0.001), and there were significant differences between baseline and end of treatment and between baseline and SVR12. Subgroup analyses showed no significant differences in SVR rates according to patient age, sex, HCV genotype (subtype), Child-Pugh classification, modified ALBI grade, presence of ascites, presence of hepatic coma, or history of hepatocellular carcinoma. In all subpopulations, the SVR rates were higher than 80%. There were no severe adverse events associated with the treatment. The SOF/VEL regimen showed good virological efficacy and acceptable safety even in patients with HCV-related decompensated cirrhosis.


Subject(s)
Antiviral Agents/therapeutic use , Carbamates/therapeutic use , Hepacivirus/drug effects , Hepatitis C, Chronic/drug therapy , Heterocyclic Compounds, 4 or More Rings/therapeutic use , Liver Cirrhosis/virology , Sofosbuvir/therapeutic use , Aged , Drug Combinations , Female , Genotype , Hepacivirus/genetics , Hepatitis C, Chronic/complications , Humans , Japan , Male , Middle Aged , Sustained Virologic Response
5.
Clin Infect Dis ; 73(9): e3349-e3354, 2021 11 02.
Article in English | MEDLINE | ID: mdl-33544129

ABSTRACT

BACKGROUND: It is unclear whether the fibrosis 4 index (FIB-4), a marker of liver fibrosis, at baseline and change in FIB-4 after sustained virological response (SVR) is associated with incident hepatocellular carcinoma (HCC) risk. In this study, we examined the association of incident HCC risk with baseline FIB-4 and sustained high FIB-4 (>3.25) at any time point after SVR. METHODS: A total of 3823 patients who received direct-acting antiviral treatment and achieved SVR were enrolled. The FIB-4 was measured 24 weeks after the end of direct-acting antiviral treatment and achievement of SVR (SVR24), and 1, 2, and 3 years after SVR24, after which subsequent HCC development was investigated. RESULTS: In patients with an FIB-4 >3.25 at SVR24 and 1, 2, and 3 years after SVR24, subsequent HCC development was significantly higher than in those with an FIB-4 ≤3.25 at each point. The rates of HCC development 1, 2, 3, and 4 years after SVR24 were significantly higher in patients with sustained FIB-4 >3.25 than in those whose FIB-4 decreased to ≤3.25 (5.4%, 9.2%, 11.7%, and 16.0%, respectively, vs 2.2%, 3.1%, 3.7%, and 4.4%; P < .001). The adjusted hazard ratios (95% confidence intervals) for an FIB-4 >3.25 at SVR24 and 1, 2, and 3 years later were 3.38 (2.4-4.8), 2.95 (1.9-4.7), 2.62 (1.3-5.1), and 3.37 (1.4-9.8), respectively. CONCLUSIONS: The FIB-4 could be used to assess HCC development risk at any time after SVR, and changes in FIB-4 were associated with changes in the HCC development risk. Repeated assessments of FIB-4 could serve as a prognostic indicator of a high-risk HCC cohort that may require more intensive HCC surveillance strategy.


Subject(s)
Carcinoma, Hepatocellular , Hepatitis C, Chronic , Liver Neoplasms , Antiviral Agents/therapeutic use , Carcinoma, Hepatocellular/epidemiology , Hepacivirus , Hepatitis C, Chronic/complications , Hepatitis C, Chronic/drug therapy , Humans , Liver Cirrhosis/drug therapy , Liver Cirrhosis/epidemiology , Liver Neoplasms/epidemiology , Risk Factors , Sustained Virologic Response
6.
Sci Rep ; 10(1): 13021, 2020 08 03.
Article in English | MEDLINE | ID: mdl-32747646

ABSTRACT

Nucleos(t)ide analogs (NA) suppress hepatitis B virus (HBV) replication and reduce the risk of hepatocellular carcinoma (HCC). However, NA cannot suppress carcinogenesis completely in patients with chronic hepatitis B. The aims of this study were to identify risk factors for HCC and develop a refined carcinogenesis prediction model. Patients receiving NA therapy (n = 1,183) were recruited retrospectively from the 16 hospitals. All patients had been receiving NA continuously for more than 1 year until the end of the follow-up. During a median follow-up of 4.9 (1.0-12.9) years, 52 (4.4%) patients developed HCC. A multivariate analysis revealed that male gender, older age, lower platelet counts at the baseline, and detectable HBV DNA during NA therapy were independent predictive factors of HCC development. The PAGE-B score was calculated by using these factors. 240 (20.3%), 661 (55.9%), and 282 (23.8%) patients were classified into low-, intermediate-, and high-risk groups, respectively. In the intermediate- and high-risk group, detectable HBV DNA was significantly associated with a higher risk of HCC development compared with continuously undetectable HBV DNA, respectively (HR 3.338; 95% CI 1.045-10.66/HR 3.191; 95% CI 1.543-6.597). PAGE-B-DNA, which is the combined PAGE-B and HBV DNA status, was valuable for a more refined stratification of PAGE-B.


Subject(s)
Carcinoma, Hepatocellular/drug therapy , Carcinoma, Hepatocellular/virology , DNA, Viral/analysis , Hepatitis B virus/genetics , Liver Neoplasms/drug therapy , Liver Neoplasms/virology , Nucleotides/therapeutic use , Carcinoma, Hepatocellular/diagnosis , Carcinoma, Hepatocellular/epidemiology , Female , Humans , Incidence , Liver Neoplasms/diagnosis , Liver Neoplasms/epidemiology , Male , Middle Aged , Proportional Hazards Models , Regression Analysis , Risk Factors
7.
Hepatol Res ; 49(10): 1114-1120, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31077527

ABSTRACT

AIM: The present study aimed to determine the real-world efficacy and safety of the non-structural protein (NS)5A inhibitor elbasvir (EBR) combined with the NS3/4A protease inhibitor grazoprevir (GZR) in patients with hepatitis C virus (HCV) genotype 1 (GT1) infection. METHODS: This study retrospectively evaluated the rate of sustained virologic response at 12 weeks post-treatment (SVR12) and the safety of EBR/GZR treatment in 159 men and 194 women with a median age of 72 years, and it assessed factors associated with the SVR12 rate. The attending physicians were responsible for selecting candidate patients for EBR/GZR in this retrospective study. RESULTS: Treatment outcomes for EBR/GZR were good in direct-acting antiviral (DAA)-naïve patients, of whom 99.4% achieved SVR. Of 353 patients, 10 (2.9%) had treatment failure. Of these patients, eight previously underwent DAA therapy, and the remaining two had NS5A-L31/Y93 double mutation. The SVR rate was 50% (8/16 patients) in patients who previously underwent DAA therapy, and 18.2% (2/11 patients) in patients with NS5A-L31/Y93 double mutation. On multivariate logistic regression analysis, NS5A-Y31/Y93 double mutation (odds ratio 356.3; 95% confidence interval, 23.91-16 940; P < 0.0001) was identified as an independent predictor of treatment failure. No serious adverse events were observed with EBR/GZR therapy. CONCLUSIONS: The SVR rate of EBR/GZR would have been 100% in patients without either a history of DAA therapy or double mutation. This combination of drugs could be safely given and is, thus, considered a highly useful first-line treatment for DAA-naïve patients with HCV.

8.
J Gastroenterol ; 53(10): 1142-1150, 2018 Oct.
Article in English | MEDLINE | ID: mdl-29626296

ABSTRACT

BACKGROUND: We aimed to describe the real-world efficacy and safety of combination therapy with ledipasvir and sofosbuvir (LDV/SOF) for chronic hepatitis C virus (HCV) genotype 1 (GT1) infection. METHODS: This retrospective analysis of a prospective, nationwide, multicenter registry included GT1-infected patients treated with LDV/SOF for 12 weeks. We assessed the rate of sustained virological response at 12 weeks post-treatment (SVR12), incidence of adverse events, and serum markers of hepatocellular carcinoma (HCC). RESULTS: Among the 1461 patients included (mean age, 69 years; 29.5% aged > 75 years; cirrhosis, 23.8%; history of treatment for HCC, 10.9%), the overall SVR12 rate was 98.4% (1438/1461). Factors associated with treatment failure were cirrhosis (odds ratio, 4.19; p = 0.014) and resistance-associated substitutions (RASs) in NS5A at baseline (odds ratio, 7.78; p = 0.0004). The SVR12 rate in patients with cirrhosis and NS5A RASs was 93.0% compared to 100% in patients without cirrhosis or NS5A RASs. In patients with SVR, the levels of alpha-fetoprotein (AFP), AFP-L3, and Mac-2 binding protein glycosylation isomer (M2BPGi) decreased from baseline to end of treatment (from 13.4 ± 37.6 to 6.0 ± 10.6 ng/mL, p < 0.0001; from 2.2 ± 4.9 to 1.5 ± 6.3%, p < 0.005; and from 3.6 ± 3.7 to 2.0 ± 3.5 cut-off index, p < 0.0001; respectively). Adverse events were rare and not associated with age. No decrease in estimated glomerular filtration rate was observed in patients with baseline chronic kidney disease stage 3. CONCLUSIONS: LDV/SOF therapy is highly effective and safe in elderly Japanese patients with HCV GT1, even in the presence of cirrhosis or NS5A RASs. Patients with SVR may have a lower risk of HCC.


Subject(s)
Antiviral Agents/therapeutic use , Benzimidazoles/therapeutic use , Fluorenes/therapeutic use , Hepacivirus/drug effects , Hepacivirus/genetics , Hepatitis C, Chronic/drug therapy , Hepatitis C, Chronic/virology , Sofosbuvir/therapeutic use , Adult , Aged , Aged, 80 and over , Antiviral Agents/adverse effects , Benzimidazoles/adverse effects , Carcinoma, Hepatocellular/blood , Carcinoma, Hepatocellular/etiology , Drug Therapy, Combination , Female , Fluorenes/adverse effects , Hepatitis C, Chronic/blood , Hepatitis C, Chronic/complications , Humans , Japan/epidemiology , Liver Cirrhosis/drug therapy , Liver Cirrhosis/etiology , Liver Cirrhosis/pathology , Liver Neoplasms/blood , Liver Neoplasms/etiology , Male , Middle Aged , Polymorphism, Single Nucleotide , Prospective Studies , Red Cross , Retrospective Studies , Risk , Sofosbuvir/adverse effects , Sustained Virologic Response , Treatment Failure , Viral Nonstructural Proteins/analysis , Young Adult , alpha-Fetoproteins/analysis
9.
Hepatol Res ; 48(9): 746-756, 2018 Aug.
Article in English | MEDLINE | ID: mdl-29480939

ABSTRACT

AIM: To evaluate the virologic responses and clinical course of daclatasvir plus asunaprevir treatment in non-hemodialysis (non-HD) and hemodialysis (HD) patients infected with genotype 1 hepatitis C virus (HCV). METHODS: A total of 1113 non-HD patients and 67 HD patients were assessed. To evaluate pretreatment factors contributing to sustained virological response at 12 weeks (SVR12), univariate and multivariate analyses were carried out. To adjust for differences in patient background, propensity score matching was undertaken. RESULTS: The overall SVR12 rates were 91.6% in non-HD patients and 95.5% in HD patients. Compared with non-HD patients, HD patients were younger, were more likely to be male, were less likely to have received interferon-based pretreatment, had a lower viral load, and had lower levels of alanine transaminase, hemoglobin, and α-fetoprotein. Multivariate analysis revealed that viral load, α-fetoprotein, L31 substitution negative, and Y93 substitution negative were independent predictive factors for SVR12 in non-HD patients. The proportion of patients with undetectable HCV-RNA during the initial 4 weeks was significantly higher in HD patients than in non-HD patients. The SVR12 rate was clearly higher in HD patients than in non-HD patients, although the difference was not statistically significant. After propensity score matching to adjust for viral load, α-fetoprotein, L31 substitution, and Y93 substitution, these trends disappeared. CONCLUSIONS: For treatment of HCV genotype 1 infection, daclatasvir plus asunaprevir is useful not only in non-HD patients but also in HD patients. Viral load, α-fetoprotein levels, L31 substitution, and Y93 substitution influence treatment course and outcome.

10.
PLoS One ; 11(10): e0165339, 2016.
Article in English | MEDLINE | ID: mdl-27776192

ABSTRACT

BACKGROUNDS & AIMS: We aimed to clarify the characteristics of resistance-associated substitutions (RASs) after treatment failure with NS5A inhibitor, daclatasvir (DCV) in combination with NS3/4A inhibitor, asunaprevir (ASV), in patients with chronic hepatitis C virus genotype 1b infection. METHODS: This is a nationwide multicenter study conducted by the Japanese Red Cross Liver Study Group. The sera were obtained from 68 patients with virological failure after 24 weeks of DCV/ASV treatment. RASs in NS5A and NS3 were determined by population sequencing. RESULTS: The frequency of signature RASs at position D168 of NS3 was 68%, and at positions L31 and Y93 of NS5A was 79 and 76%, respectively. The frequency of dual signature RASs in NS5A (L31-RAS and Y93-RAS) was 63%. RASs at L28, R30, P32, Q54, P58, and A92 in addition to dual signature RAS were detected in 5, 5, 1, 22, 2, and 0 patients, respectively. In total, triple, quadruple, and quintuple RASs in combination with dual signature RAS were detected in 35, 10, and 1.5% patients, respectively. These RASs were detected in patients without baseline RASs or who prematurely discontinued therapy. Co-existence of D168 RAS in NS3 and L31 and/or Y93 RAS in NS5A was observed in 62% of patients. CONCLUSION: Treatment-emergent RASs after failure with DCV/ASV combination therapy are highly complex in more than 50% of the patients. The identification of complex RAS patterns, which may indicate high levels of resistance to NS5A inhibitors, highlights the need for RAS sequencing when considering re-treatment with regimens including NS5A inhibitors.


Subject(s)
Hepatitis C, Chronic/drug therapy , Imidazoles/therapeutic use , Isoquinolines/therapeutic use , Sulfonamides/therapeutic use , Aged , Carbamates , Drug Therapy, Combination , Female , Hepacivirus/drug effects , Hepatitis C, Chronic/virology , Humans , Imidazoles/administration & dosage , Imidazoles/pharmacology , Isoquinolines/administration & dosage , Isoquinolines/pharmacology , Male , Middle Aged , Pyrrolidines , Sulfonamides/administration & dosage , Sulfonamides/pharmacology , Treatment Outcome , Valine/analogs & derivatives
11.
Intern Med ; 53(22): 2581-3, 2014.
Article in English | MEDLINE | ID: mdl-25400178

ABSTRACT

A 29-year-old woman with ulcerative colitis underwent total colectomy with ileal-pouch-anal canal anastomosis in 1999. After the surgery, she developed refractory pouchitis. We administered metronidazole, mesalamine and ciprofloxacin; however, her clinical symptoms improved only very slightly. We initiated treatment with infliximab in June 2011 and discontinued the antibiotics. Thereafter, the patient's abdominal symptoms quickly improved. We discontinued the infliximab therapy in June 2012, after which time, the patient's abdominal symptoms remained in remission for 40 weeks, without the use of antibiotics. This report suggests that infliximab is useful not only for improving the clinical symptoms of refractory pouchitis, but also discontinuing antibiotic therapy in such patients.


Subject(s)
Antibodies, Monoclonal/therapeutic use , Colitis, Ulcerative/surgery , Gastrointestinal Agents/therapeutic use , Pouchitis/drug therapy , Adult , Anti-Bacterial Agents/therapeutic use , Anti-Inflammatory Agents/therapeutic use , Female , Humans , Infliximab , Pouchitis/etiology , Proctocolectomy, Restorative/adverse effects
12.
Intern Med ; 52(5): 547-9, 2013.
Article in English | MEDLINE | ID: mdl-23448762

ABSTRACT

The coexistence of idiopathic thrombocytopenic purpura (ITP) and active ulcerative colitis (UC) has been reported. We herein report a rare case of UC accompanied by ITP and Helicobacter pylori (H. pylori) infection. A female UC patient was diagnosed with ITP. At that time, the UC was almost in remission and we suspected that the ITP was caused by some factor other than UC. Accordingly, we found H. pylori infection and administered H. pylori eradication therapy. Consequently, the patient's serum platelet count recovered dramatically. Our report demonstrates the importance of conducting examinations for H. pylori infection in ITP patients, even those with UC.


Subject(s)
Colitis, Ulcerative/diagnosis , Helicobacter Infections/diagnosis , Helicobacter pylori , Purpura, Thrombocytopenic, Idiopathic/diagnosis , Adult , Colitis, Ulcerative/complications , Female , Helicobacter Infections/complications , Helicobacter pylori/isolation & purification , Humans , Purpura, Thrombocytopenic, Idiopathic/complications
13.
PLoS One ; 7(7): e41955, 2012.
Article in English | MEDLINE | ID: mdl-22848672

ABSTRACT

Gonadotropin-releasing hormone (GnRH) is a neuroendocrine peptide that plays a central role in the vertebrate hypothalamo-pituitary axis. The roles of GnRH in the control of vertebrate reproductive functions have been established, while its non-reproductive function has been suggested but less well understood. Here we show that the tunicate Ciona intestinalis has in its non-reproductive larval stage a prominent GnRH system spanning the entire length of the nervous system. Tunicate GnRH receptors are phylogenetically closest to vertebrate GnRH receptors, yet functional analysis of the receptors revealed that these simple chordates have evolved a unique GnRH system with multiple ligands and receptor heterodimerization enabling complex regulation. One of the gnrh genes is conspicuously expressed in the motor ganglion and nerve cord, which are homologous structures to the hindbrain and spinal cord of vertebrates. Correspondingly, GnRH receptor genes were found to be expressed in the tail muscle and notochord of embryos, both of which are phylotypic axial structures along the nerve cord. Our findings suggest a novel non-reproductive role of GnRH in tunicates. Furthermore, we present evidence that GnRH-producing cells are present in the hindbrain and spinal cord of the medaka, Oryzias latipes, thereby suggesting the deep evolutionary origin of a non-reproductive GnRH system in chordates.


Subject(s)
Chordata/metabolism , Conserved Sequence , Gonadotropin-Releasing Hormone/metabolism , Animals , Chordata/genetics , Evolution, Molecular , Gene Expression Regulation , Gonadotropin-Releasing Hormone/genetics , Neurons/metabolism , Phylogeny , Protein Transport , Receptors, LHRH/genetics , Receptors, LHRH/metabolism , Rhombencephalon/cytology , Sequence Homology, Nucleic Acid , Species Specificity , Spinal Cord/cytology
14.
Cell Signal ; 24(8): 1573-82, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22516102

ABSTRACT

Recent reports have described the involvement of the diacylglycerol kinase (DGK) family in various pathological conditions. In an animal model of transient ischemia, DGKζ containing a nuclear localization signal (NLS) is shown to translocate quickly from the nucleus to the cytoplasm in hippocampal neurons and to disappear gradually after reperfusion. Those neurons die a delayed neuronal death because of glutamate excitotoxicity. This study investigated the molecular mechanism and functional relation linking DGKζ and neuronal death. In primary cultured neurons, transient exposure to excitotoxic concentration of glutamate led to cytoplasmic accumulation of DGKζ followed by its down-regulation. Results showed that DGKζ down-regulation was caused by proteolytic degradation through the ubiquitin-proteasome system (UPS) rather than transcriptional inhibition. DGKζ polyubiquitination was inhibited in the presence of nuclear export inhibitor leptomycin B. Furthermore, NLS-deleted mutant DGKζΔNLS, which mainly localizes to the cytoplasm, was ubiquitinated more heavily than wild-type DGKζ. From a functional perspective, in vitro gene silencing of DGKζ via specific siRNA enhanced DNA fragmentation in cultured neurons after glutamate exposure. At the organismal level, hippocampal neurons of DGKζ-deficient mice showed vulnerability to kainate-induced seizures. In addition, DGKζ-deficient hippocampus exhibited a significant increase in Ser807/811 phosphorylated retinoblastoma protein levels together with up-regulation of the expression of type D and E cyclins, indicative of cell cycle reentry. Collectively, these results suggest that 1) glutamate excitotoxicity induces nucleocytoplasmic translocation of DGKζ followed by its degradation through the cytoplasmic UPS in hippocampal neurons and that 2) DGKζ-deficient neurons do not succumb directly to apoptosis, although they are more vulnerable to excitotoxicity because of aberrant cell cycle reentry.


Subject(s)
Apoptosis , Cell Cycle , Cytoplasm/metabolism , Diacylglycerol Kinase/metabolism , Neurons/cytology , Proteasome Endopeptidase Complex/metabolism , Ubiquitin/metabolism , Animals , Apoptosis/drug effects , Cell Cycle/drug effects , Diacylglycerol Kinase/deficiency , Glutamic Acid/pharmacology , Hippocampus/cytology , Hippocampus/drug effects , Male , Mice , Mice, Inbred C57BL , Neurons/drug effects , Rats , Rats, Wistar , Structure-Activity Relationship
15.
Biochem Biophys Res Commun ; 420(2): 479-84, 2012 Apr 06.
Article in English | MEDLINE | ID: mdl-22450320

ABSTRACT

Diacylglycerol kinase (DGK) plays an important role in phosphoinositide signaling cascade by regulating the intracellular level of diacylglycerol and phosphatidic acid. The DGK family is involved in various pathophysiological responses that are mediated through unique binding partners in different tissues and cells. In this study, we identified a small GTPase effector protein, IQGAP1, as a novel DGKζ-associated complex protein. A bacterial endotoxin, lipopolysaccharide (LPS), facilitated the complex formation in macrophages. Both proteins co-localized at the edge and phagocytic cup of the cell. Furthermore, RNA interference-mediated knockdown of DGKζ or IQGAP1 impaired LPS-induced Rac1 activation. Primary macrophages derived from DGKζ(-/-) mice attenuated LPS-induced phagocytosis of bacteria. These results suggest that DGKζ is involved in IQGAP1/Rac1-mediated phagocytosis upon LPS stimulation in macrophages.


Subject(s)
Diacylglycerol Kinase/metabolism , Macrophages/immunology , Neuropeptides/metabolism , Phagocytosis , rac GTP-Binding Proteins/metabolism , ras GTPase-Activating Proteins/metabolism , Animals , Cells, Cultured , Diacylglycerol Kinase/genetics , Humans , Lipopolysaccharides/immunology , Macrophage Activation , Mice , Mice, Inbred C57BL , rac1 GTP-Binding Protein
16.
J Biochem ; 151(4): 391-401, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22247562

ABSTRACT

Differences in the conformation of the pleckstrin homology (PH) domain of switch-associated protein-70 (SWAP-70) in solution and at the lipid bilayer membrane surface were examined using CD, fluorescence and NMR spectroscopy. Intracellular relocalization of SWAP-70 from the cytoplasm to the plasma membrane and then to the nucleus is associated with its cellular functions. The PH domain of SWAP-70 contains a phosphoinositide-binding site and a nuclear localization signal, which localize SWAP-70 to the plasma membrane and nucleus, respectively. CD and fluorescence spectra showed that a significant conformational alteration involving formation of disordered structure occurs when the PH domain binds to D-myo-phosphatidylinositol 3,4,5-trisphosphate or D-myo-phosphatidylinositol 4,5-bisphosphate embedded in lipid bilayer vesicles. NMR spectra indicate that Ala and Trp residues located in the C-terminal α-helix of the PH domain undergo conformational alterations to form a disordered structure at the vesicle surface. These conformational alterations were not induced by association with inositol 1,3,4,5-tetrakisphosphate in solution or coexistence of phosphatidylcholine vesicles. Interaction with the plane of the lipid bilayer via association with the phosphoinositides is required for the unfolding of the C-terminal α-helix of the PH domain. The unwinding of the C-terminal α-helix could regulate the functions of SWAP-70 at the plasma membrane surface.


Subject(s)
Cell Membrane/chemistry , DNA-Binding Proteins/chemistry , Guanine Nucleotide Exchange Factors/chemistry , Nuclear Proteins/chemistry , Active Transport, Cell Nucleus , Amino Acid Sequence , Circular Dichroism , Humans , Lipid Bilayers/chemistry , Minor Histocompatibility Antigens , Molecular Sequence Data , Nuclear Localization Signals , Phosphatidylinositols/chemistry , Phosphorylcholine/chemistry , Protein Binding , Protein Structure, Secondary , Protein Structure, Tertiary
17.
Exp Cell Res ; 317(20): 2853-63, 2011 Dec 10.
Article in English | MEDLINE | ID: mdl-21996351

ABSTRACT

Diacylglycerol kinase (DGK) is involved in the regulation of lipid-mediated signal transduction through the metabolism of a second messenger diacylglycerol. Of the DGK family, DGKζ, which contains a nuclear localization signal, localizes mainly to the nucleus but translocates to the cytoplasm under pathological conditions. However, the detailed mechanism of translocation and its functional significance remain unclear. To elucidate these issues, we used a proteomic approach to search for protein targets that interact with DGKζ. Results show that nucleosome assembly protein (NAP) 1-like 1 (NAP1L1) and NAP1-like 4 (NAP1L4) are identified as novel DGKζ binding partners. NAP1Ls constitutively shuttle between the nucleus and the cytoplasm in transfected HEK293 cells. The molecular interaction of DGKζ and NAP1Ls prohibits nuclear import of DGKζ because binding of NAP1Ls to DGKζ blocks import carrier proteins, Qip1 and NPI1, to interact with DGKζ, leading to cytoplasmic tethering of DGKζ. In addition, overexpression of NAP1Ls exerts a protective effect against doxorubicin-induced cytotoxicity. These findings suggest that NAP1Ls are involved in a novel molecular basis for the regulation of nucleocytoplasmic shuttling of DGKζ and provide a clue to examine functional significance of its translocation under pathological conditions.


Subject(s)
Diacylglycerol Kinase/metabolism , Karyopherins/metabolism , Nuclear Proteins/metabolism , Nucleosome Assembly Protein 1/metabolism , Nucleosomes/metabolism , Animals , COS Cells , Cells, Cultured , Chlorocebus aethiops , Cytoplasm/genetics , Cytoplasm/metabolism , HEK293 Cells , HeLa Cells , Humans , Nuclear Proteins/genetics , Nucleosome Assembly Protein 1/genetics , Nucleosomes/genetics , Protein Binding/genetics , Protein Binding/physiology , Protein Transport , Proteomics/methods , Signal Transduction , Tumor Cells, Cultured , alpha Karyopherins/metabolism
18.
Neurosci Lett ; 472(3): 188-93, 2010 Mar 26.
Article in English | MEDLINE | ID: mdl-20138965

ABSTRACT

Phospholipase C-delta1 (PLCdelta1) is the most fundamental form of the eukaryotic PLC and thought to play important roles in the regulation of cells. We previously reported that PLCdelta1 shuttles between the cytoplasm and nucleus, and an influx of Ca2+ triggers the nuclear import of PLCdelta1 via Ca2+-dependent interaction with importin beta1, although the physiological meaning of this is unclear. Here we have examined the distribution of PLCdelta1 using primary cultures of rat hippocampal neurons. Treatment of 7DIV neurons with ionomycin or thapsigargin caused the nuclear localization of PLCdelta1 as has been observed in other cell lines. Similar results were obtained with neurons treated with glutamate, suggesting that the nuclear localization of PLCdelta1 plays some roles in excitotoxicity associated with ischemic stress. Generally, cells undergoing ischemic or hypoxic cell death show nuclear shrinkage. We confirmed that a massive influx of Ca2+ caused similar results. Furthermore, overexpression of GFP-PLCdelta1 facilitated ionomycin-induced nuclear shrinkage in embryonic fibroblasts derived from PLCdelta1 gene-knockout mice (PLCdelta1KO-MEF). By contrast, an E341A mutant that cannot bind with importin beta1 and be imported into the nucleus by ionomycin and also lacks enzymatic activity did not cause nuclear shrinkage in PLCdelta1KO-MEF. Nuclear translocation and the PLC activity of PLCdelta1, therefore, may regulate the nuclear shape by controlling the nuclear scaffold during stress-induced cell death caused by high levels of Ca2+.


Subject(s)
Calcium/metabolism , Cell Nucleus/metabolism , Cell Nucleus/ultrastructure , Phospholipase C delta/metabolism , Active Transport, Cell Nucleus , Animals , Calcium-Transporting ATPases/antagonists & inhibitors , Cell Hypoxia , Cell Nucleus Shape , Cells, Cultured , Fibroblasts/enzymology , Glutamic Acid/pharmacology , Hippocampus/cytology , Ionomycin/pharmacology , Ionophores/pharmacology , Mice , Mice, Knockout , Mutation , Neurons/metabolism , Neurons/ultrastructure , Phospholipase C delta/genetics , Rats , Thapsigargin/pharmacology
19.
J Clin Ultrasound ; 38(1): 41-4, 2010 Jan.
Article in English | MEDLINE | ID: mdl-19827127

ABSTRACT

Gastroepiploic artery aneurysm (GEAA) is very rare.1 Furthermore, most GEAA cases are diagnosed after their rupture. We report a case of asymptomatic GEAA. The patient was a 61-year-old man. Sonography (US) revealed a 2-cm anechoic mass in the epigastrium near the anterior abdominal wall. Color Doppler US and contrast-enhanced US showed arterial flow within the mass leading to the diagnosisof visceral artery aneurysm. CT and angiography confirmed the diagnosis of right GEAA, and the aneurysm was treated successfully with embolization. Follow-up US 6 months later confirmed the absence of blood flow within the lesion.


Subject(s)
Aneurysm/diagnostic imaging , Gastroepiploic Artery/diagnostic imaging , Abdominal Pain/etiology , Aneurysm/complications , Contrast Media , Diagnosis, Differential , Follow-Up Studies , Humans , Image Enhancement/methods , Male , Middle Aged , Ultrasonography, Doppler, Color/methods
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