Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Artículo en Inglés | MEDLINE | ID: mdl-38694541

RESUMEN

Objectives: This study aimed to determine the impact of the coronavirus disease 2019 (COVID-19) pandemic on the treatment of acute cholangitis caused by choledocholithiasis. Methods: The Japanese government declared a state of emergency in April 2020 due to the COVID-19 pandemic. We retrospectively reviewed the medical records of 309 patients who underwent endoscopic retrograde cholangiopancreatography (ERCP) for acute cholangitis caused by choledocholithiasis between April 2017 and December 2022. Results: Patients were categorized into a pregroup (n = 134) and a postgroup (n = 175), depending on whether they were diagnosed before or after the state of emergency declaration. The total number of ERCP cases and the number of ERCP cases with endoscopic stone removals increased after the state of emergency declaration. Compared with the pregroup, the numbers of patients with performance status of 0-1 and surgically altered anatomy increased, whereas the numbers of patients taking oral antiplatelets or anticoagulants and those with cerebrovascular disease decreased in the postgroup. The number of single-stage endoscopic stone removals increased and hospital stays were significantly shorter in the postgroup. No differences in adverse event rates were detected between the two groups. Conclusions: Although our hospital provides tertiary care, the number of patients with cholangitis in good general condition and no underlying disease increased after the state of emergency declaration. The COVID-19 pandemic resulted in an increase in the number of single-stage endoscopic treatments and shortened hospital stays for patients with acute cholangitis caused by choledocholithiasis. No safety issues with ERCP were detected, even during the pandemic.

2.
World J Gastroenterol ; 30(28): 3428-3446, 2024 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-39091710

RESUMEN

BACKGROUND: Alcohol-associated liver disease (ALD) is a leading cause of liver-related morbidity and mortality, but there are no therapeutic targets and modalities to prevent ALD-related liver fibrosis. Peroxisome proliferator activated receptor (PPAR) α and δ play a key role in lipid metabolism and intestinal barrier homeostasis, which are major contributors to the pathological progression of ALD. Meanwhile, elafibranor (EFN), which is a dual PPARα and PPARδ agonist, has reached a phase III clinical trial for the treatment of metabolic dysfunction-associated steatotic liver disease and primary biliary cholangitis. However, the benefits of EFN for ALD treatment is unknown. AIM: To evaluate the inhibitory effects of EFN on liver fibrosis and gut-intestinal barrier dysfunction in an ALD mouse model. METHODS: ALD-related liver fibrosis was induced in female C57BL/6J mice by feeding a 2.5% ethanol (EtOH)-containing Lieber-DeCarli liquid diet and intraperitoneally injecting carbon tetrachloride thrice weekly (1 mL/kg) for 8 weeks. EFN (3 and 10 mg/kg/day) was orally administered during the experimental period. Histological and molecular analyses were performed to assess the effect of EFN on steatohepatitis, fibrosis, and intestinal barrier integrity. The EFN effects on HepG2 lipotoxicity and Caco-2 barrier function were evaluated by cell-based assays. RESULTS: The hepatic steatosis, apoptosis, and fibrosis in the ALD mice model were significantly attenuated by EFN treatment. EFN promoted lipolysis and ß-oxidation and enhanced autophagic and antioxidant capacities in EtOH-stimulated HepG2 cells, primarily through PPARα activation. Moreover, EFN inhibited the Kupffer cell-mediated inflammatory response, with blunted hepatic exposure to lipopolysaccharide (LPS) and toll like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB) signaling. EFN improved intestinal hyperpermeability by restoring tight junction proteins and autophagy and by inhibiting apoptosis and proinflammatory responses. The protective effect on intestinal barrier function in the EtOH-stimulated Caco-2 cells was predominantly mediated by PPARδ activation. CONCLUSION: EFN reduced ALD-related fibrosis by inhibiting lipid accumulation and apoptosis, enhancing hepatocyte autophagic and antioxidant capacities, and suppressing LPS/TLR4/NF-κB-mediated inflammatory responses by restoring intestinal barrier function.


Asunto(s)
Chalconas , Modelos Animales de Enfermedad , Mucosa Intestinal , Cirrosis Hepática , Hepatopatías Alcohólicas , Ratones Endogámicos C57BL , PPAR alfa , Animales , Ratones , Humanos , Femenino , Hepatopatías Alcohólicas/patología , Hepatopatías Alcohólicas/metabolismo , Hepatopatías Alcohólicas/prevención & control , Hepatopatías Alcohólicas/etiología , Hepatopatías Alcohólicas/tratamiento farmacológico , PPAR alfa/metabolismo , PPAR alfa/agonistas , Chalconas/farmacología , Cirrosis Hepática/patología , Cirrosis Hepática/inducido químicamente , Cirrosis Hepática/metabolismo , Cirrosis Hepática/tratamiento farmacológico , Cirrosis Hepática/prevención & control , Mucosa Intestinal/efectos de los fármacos , Mucosa Intestinal/patología , Mucosa Intestinal/metabolismo , Células CACO-2 , Hígado/patología , Hígado/efectos de los fármacos , Hígado/metabolismo , Etanol/toxicidad , Apoptosis/efectos de los fármacos , Metabolismo de los Lípidos/efectos de los fármacos , PPAR delta/agonistas , PPAR delta/metabolismo , Transducción de Señal/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Propionatos
3.
Int J Mol Sci ; 25(5)2024 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-38473925

RESUMEN

Portal vein thrombosis (PVT), one of the most prevalent hepatic vascular conditions in patients with liver cirrhosis (LC), is associated with high mortality rates. An imbalance between a disintegrin-like metalloproteinase with thrombospondin type-1 motifs 13 (ADAMTS-13) enzyme and von Willebrand factor (VWF) is responsible for hypercoagulability, including spontaneous thrombus formation in blood vessels. Herein, we aimed to identify potential prognostic and diagnostic biomarkers in Japanese patients with LC and PVT. In total, 345 patients were divided into two groups: 40 patients who developed PVT (PVT group) and 305 who did not develop PVT (NPVT group). Among the 345 patients with LC, 81% (279/345) were deemed ineligible due to the presence of preventive comorbidities, active or recent malignancies, and organ dysfunction. The remaining 66 patients were divided into two groups: the PVT group (n = 33) and the NPVT group (n = 33). Plasma ADAMTS-13 activity (ADAMTS-13:AC) and the vWF antigen (VWF:Ag) were measured using enzyme-linked immunosorbent assays. Contrast-enhanced, three-dimensional helical computed tomography (CT) was used to detect and characterize PVT. ADAMTS-13:AC was significantly lower in the PVT group than in the NPVT group. No significant differences in plasma vWF:Ag or liver stiffness were observed between the two groups. ADAMTS-13:AC of <18.8 was an independent risk factor for PVT on multivariate analyses (odds ratio: 1.67, 95% confidence interval: 1.21-3.00, p < 0.002). The receiver operating characteristic analysis of ADAMTS-13:AC revealed an area under the curve of 0.913 in PVT detection. Patients with PVT having ADAMTS-13:AC ≥18.8 (n = 17) had higher albumin levels and better prognoses than those with ADAMTS-13:AC <18.8 (n = 16). No significant correlations of ADAMTS-13:AC levels with either fibrin degradation product or D-dimer levels were observed. ADAMTS-13:AC levels could be potential diagnostic and prognostic biomarkers for PVT in Japanese patients with LC.


Asunto(s)
Trombosis de la Vena , Factor de von Willebrand , Humanos , Factor de von Willebrand/metabolismo , Vena Porta/metabolismo , Proteína ADAMTS13 , Pronóstico , Japón , Cirrosis Hepática/patología , Trombosis de la Vena/complicaciones , Biomarcadores
4.
Cells ; 13(6)2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-38534382

RESUMEN

BACKGROUND: Liver cirrhosis leads to portal hypertension (PH) with capillarization of liver sinusoidal endothelial cells (LSECs), although drug treatment options for PH are currently limited. Sodium glucose transporter 2 inhibitors, which are antidiabetic agents, have been shown to improve endothelial dysfunction. We aimed to elucidate the effect of tofogliflozin on PH and liver fibrosis in a rat cirrhosis model. METHODS: Male-F344/NSlc rats repeatedly received carbon tetrachloride (CCl4) intraperitoneally to induce PH and liver cirrhosis alongside tofogliflozin (10 or 20 mg/kg). Portal hemodynamics and hepatic phenotypes were assessed after 14 weeks. An in vitro study investigated the effects of tofogliflozin on the crosstalk between LSEC and activated hepatic stellate cells (Ac-HSC), which are relevant to PH development. RESULTS: Tofogliflozin prevented PH with attenuated intrahepatic vasoconstriction, sinusoidal capillarization, and remodeling independent of glycemic status in CCl4-treated rats. Hepatic macrophage infiltration, proinflammatory response, and fibrogenesis were suppressed by treatment with tofogliflozin. In vitro assays showed that tofogliflozin suppressed Ac-HSC-stimulated capillarization and vasoconstriction in LSECs by enhancing the antioxidant capacity, as well as inhibited the capilliarized LSEC-stimulated contractive, profibrogenic, and proliferative activities of Ac-HSCs. CONCLUSIONS: Our study provides strong support for tofogliflozin in the prevention of liver cirrhosis-related PH.


Asunto(s)
Compuestos de Bencidrilo , Células Endoteliales , Glucósidos , Hipertensión Portal , Ratas , Masculino , Animales , Células Endoteliales/patología , Ratas Endogámicas F344 , Cirrosis Hepática/patología , Hipertensión Portal/tratamiento farmacológico
5.
Hepatol Res ; 54(3): 252-260, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37897705

RESUMEN

AIM: Entecavir (ETV) and tenofovir alafenamide fumarate (TAF) are considered safe nucleoside/nucleotide analogs (NA) for the kidney. This study aimed to investigate the long-term effects of ETV or TAF on renal function in elderly patients with chronic hepatitis B (CHB) in Japan. METHODS: The study included 246 CHB patients treated with ETV (184 patients) or TAF (62 patients) for at least 2 years. These patients were divided into two groups: those <65 years of age (130 patients) and those ≥65 years of age (116 patients). The effects of the NAs on renal functions were examined by comparing the estimated glomerular filtration rates (eGFR) from baseline to 2 years between the two groups. RESULTS: The change in eGFR from baseline to 1 or 2 years after treatment was significantly decreased in both groups. However, the amount of change at 1 and 2 years was significantly greater in the group aged ≥65 years than in the group aged <65 years. The amount of change in eGFR from baseline to 1 and 2 years after treatment was significantly greater in the group aged ≥65 years than in the group aged <65 years, regardless of the type of NA, the prior treatment history, cirrhosis/chronic hepatitis, hypertension, dyslipidemia, and diabetes. Additionally, logistic regression analysis showed that age ≥65 years was independently associated with a decreased eGFR after 2 years of NA treatment. CONCLUSIONS: Long-term administration of NA to CHB patients over 65 years of age should be carefully monitored for renal impairment.

6.
Biochim Biophys Acta Mol Cell Res ; 1871(2): 119649, 2024 02.
Artículo en Inglés | MEDLINE | ID: mdl-38097064

RESUMEN

Sarcopenia is associated with mortality in patients with nonalcoholic steatohepatitis (NASH). Angiotensin II receptor blocker (ARB) has been suggested to prevent sarcopenia, but reports on its effect on NASH-derived skeletal muscle atrophy in conjunction with insulin-like growth factor 1 (IGF-1)-mediated muscle homeostasis are few. Our aim was to examine the combined effect of the ARB losartan and IGF-1 replacement on skeletal muscle atrophy in a methionine-choline deficient (MCD) diet-fed murine steatohepatitis model. The MCD-fed mice developed steatohepatitis and skeletal muscle atrophy, as indicated by the reduction of psoas muscle mass and attenuation of forelimb and hindlimb grip strength. Significantly suppressed steatohepatitis and skeletal muscle atrophy was observed after single treatment with ARB or IGF-1, and these effects were augmented after combination treatment. Treatment with ARB and IGF-1 effectively inhibited ubiquitin proteasome-mediated protein degradation by reducing forkhead box protein O1 (FOXO1) and FOXO3a transcriptional activity in the skeletal muscle. Combined ARB and IGF-1 decreased the intramuscular expression of proinflammatory cytokines (i.e., TNFα, IL6, and IL1ß) and increased the Trolox equivalent antioxidant capacity and antioxidant enzymes (CAT, GPX1, SOD2, and CYTB). This antioxidant effect was based on downregulation of NADPH oxidase (NOX) 2, normalization of mitochondrial biogenesis and dynamics. Moreover, ARB increased the hepatic and plasma IGF-1 levels and improved steatohepatitis, leading to enhanced skeletal muscle protein synthesis mediated by IGF-1/ AKT/ mechanistic target of rapamycin signaling. Collectively, combined ARB and IGF-1 replacement could be a promising new therapeutic target for NASH-derived skeletal muscle wasting.


Asunto(s)
Enfermedad del Hígado Graso no Alcohólico , Sarcopenia , Humanos , Ratones , Animales , Factor I del Crecimiento Similar a la Insulina/genética , Factor I del Crecimiento Similar a la Insulina/metabolismo , Sarcopenia/tratamiento farmacológico , Sarcopenia/metabolismo , Sarcopenia/patología , Angiotensina II/metabolismo , Angiotensina II/farmacología , Angiotensina II/uso terapéutico , Péptidos Similares a la Insulina , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Enfermedad del Hígado Graso no Alcohólico/patología , Antagonistas de Receptores de Angiotensina/metabolismo , Antagonistas de Receptores de Angiotensina/farmacología , Antagonistas de Receptores de Angiotensina/uso terapéutico , Antioxidantes/metabolismo , Inhibidores de la Enzima Convertidora de Angiotensina/metabolismo , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Músculo Esquelético/metabolismo , Atrofia Muscular/tratamiento farmacológico , Atrofia Muscular/metabolismo , Homeostasis
7.
Diagnostics (Basel) ; 13(13)2023 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-37443613

RESUMEN

Alcohol is a major risk factor of liver cirrhosis (LC). This study aimed to elucidate a surrogate marker of sarcopenia in patients with LC of different etiology. Out of 775 patients with LC, 451 were assessed for handgrip strength and skeletal muscle mass (by computed tomography). They were then divided into two groups: alcoholic cirrhosis (AC; n = 149) and nonalcoholic cirrhosis (NAC; n = 302). Endotoxin activity (EA) levels were measured with an EA assay. Group AC showed significantly higher platelet counts (p = 0.027) and lower blood urea nitrogen levels and fibrosis-4 index than group NAC (p = 0.0020 and p = 0.038, respectively). The risk factors of sarcopenia were age ≥ 65 years, female sex, CP-C LC, Hb levels < 12 g/dL, and EA level > 0.4 in all patients with LC; hemoglobin (Hb) levels < 12 g/dL and EA level > 0.4 in group AC; and age ≥ 65 years, CP-C LC, and Hb levels < 12 g/dL in group NAC. The prediction accuracy of Hb for sarcopenia in group AC, group NAC, and all patients was 83.6%, 75.9%, and 78.1% (sensitivity: 92.0%, 69.0%, and 80.2%; specificity: 66.4%, 71.0%, and 64.0%), respectively. Although not significant, the predictive performance was better when using the combination of Hb and EA measurements than when using Hb alone in group AC but was comparable in all patients. Hb levels can predict sarcopenia in patients with LC, but in those with AC, the combination of Hb and EA improves the prediction performance.

8.
In Vivo ; 37(3): 1226-1235, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37103093

RESUMEN

BACKGROUND/AIM: The management of refractory ascites is critical for the treatment of patients with decompensated cirrhosis. This study aimed to evaluate the feasibility and safety of cell-free and concentrated ascites reinfusion therapy (CART) in patients with cirrhosis and refractory ascites, with a focus on changes in coagulation and fibrinolytic factors in ascitic fluid following CART. PATIENTS AND METHODS: This was a retrospective cohort study including 23 patients with refractory ascites undergoing CART. Serum endotoxin activity (EA) before and after CART and the levels of coagulation and fibrinolytic factors and proinflammatory cytokines in original and processed ascitic fluid were measured. The Ascites Symptom Inventory-7 (ASI-7) scale was used for subjective symptom assessment before and after CART. RESULTS: Body weight and waist circumference significantly decreased after CART, whereas serum EA did not significantly change after CART. Similar to the previous reports, ascitic fluid concentrations of total protein, albumin, high-density lipoprotein cholesterol, γ-globulin, and immunoglobulin G levels were significantly increased after CART; mild elevations in body temperature and interleukin 6 and tumor necrosis factor-alpha levels in ascitic fluid were also observed. Importantly, the levels of antithrombin-III, factor VII, and X, which are useful for patients with decompensated cirrhosis, were markedly increased in the reinfused fluid during CART. Finally, the total ASI-7 score was significantly lower following CART, compared with the pre-CART score. CONCLUSION: CART is an effective and safe approach for the treatment of refractory ascites that allows the intravenous reinfusion of coagulation and fibrinolytic factors in the filtered and concentrated ascites.


Asunto(s)
Ascitis , Líquido Ascítico , Humanos , Ascitis/terapia , Ascitis/metabolismo , Ascitis/patología , Estudios Retrospectivos , Japón , Líquido Ascítico/metabolismo , Cirrosis Hepática/complicaciones , Cirrosis Hepática/terapia , Cirrosis Hepática/metabolismo
9.
Biochem Biophys Res Commun ; 640: 56-63, 2023 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-36502632

RESUMEN

Carcinogenesis is often associated with alteration of epigenetic marks, including histone modifications. The global level and local distribution of specific histone modifications have been revealed to be prognostic factors in many cancers. However, the functional roles of histone modifications in oral squamous cell carcinoma (OSCC) remain unclear. This study investigates the levels of various histone modifications in 6 types of OSCC cell lines. We found that the level of H3K9me3 was significantly high in metastatic cell lines. In addition, the loss of H3K9me3 by SUV39H1 and SUV39H2 knockdown suppressed cell proliferation and cell migration. Our results indicate that a high level of H3K9me3 could be a marker of metastasis and possibly a therapeutic target for OSCC treatment.


Asunto(s)
Histonas , Neoplasias de la Boca , Carcinoma de Células Escamosas de Cabeza y Cuello , Humanos , Línea Celular Tumoral , Histonas/metabolismo , Neoplasias de la Boca/genética , Neoplasias de la Boca/patología , Carcinoma de Células Escamosas de Cabeza y Cuello/genética , Carcinoma de Células Escamosas de Cabeza y Cuello/patología
10.
DEN Open ; 3(1): e177, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36304177

RESUMEN

Objectives: Serial pancreatic juice aspiration cytological examination (SPACE) via endoscopic retrograde cholangiopancreatography is a useful diagnostic method for early-stage pancreatic cancer, such as carcinoma in situ that are difficult to diagnose by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). However, the diagnostic accuracy of SPACE is low, which is attributed to problems regarding specimen treatment. Hence, we evaluated the diagnostic efficacy of liquid-based cytology (LBC) in pancreatic juice cytology for pancreatic cancer. Methods: We retrospectively analyzed 24 patients with suspected pancreatic cancer that was difficult to diagnose by endoscopic ultrasound-guided fine needle aspiration who underwent SPACE using LBC between April 2017 and April 2021. Results: The most common reason for performing SPACE was localized stenosis of the main pancreatic duct without a mass. Eleven patients were diagnosed with malignancy after surgical resection, nine of whom had pancreatic ductal adenocarcinoma. Ten patients were diagnosed as benign after a follow-up of more than 1 year. The nine cases of malignancy were diagnosed before surgical resection by SPACE using LBC, with a sensitivity of 81.8% and specificity of 100%. The overall diagnostic accuracy was 91.7%. A total of 152 LBC examinations were performed via SPACE, with an adequate sample collection rate of 88.9%. No adverse events, including acute pancreatitis, occurred after endoscopic retrograde cholangiopancreatography. Conclusion: SPACE with LBC offers good diagnostic efficacy in patients with pancreatic cancer that is difficult to diagnose by endoscopic ultrasound-guided fine needle aspiration.

11.
Cancer Diagn Progn ; 2(2): 184-193, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35399181

RESUMEN

Background/Aim: Sarcopenia increases the mortality in patients with cirrhosis. Approximately 60% of zinc is accumulated in skeletal muscle. We aimed to determine the role of subclinical zinc deficiency on sarcopenia development in patients with cirrhosis. Patients and Methods: We enrolled 151 patients with cirrhosis and divided them into the group with normal serum zinc levels (Group N: 80-130 µg/dl; n=38) and group with subclinical zinc deficiency (Group D: <80 µg/dl; n=113). The risk factors for sarcopenia were then investigated. Results: Group D had more sarcopenia cases than Group N (31.0% vs. 13.2%). In group D, HGS exhibited a weakly positive but significant correlation with serum zinc levels (R=0.287, p=0.00212), serum zinc levels negatively correlated with both ammonia and myostatin levels (R=-0.254, p=0.0078; R=-0.33, p<0.01), and low zinc levels were independently associated with sarcopenia development. Conclusion: Patients with cirrhosis showing subclinical zinc deficiency have a significantly higher risk of developing sarcopenia.

12.
BMC Gastroenterol ; 22(1): 101, 2022 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-35255813

RESUMEN

BACKGROUND: Protein-losing gastroenteropathy (PLGE) is a syndrome with a chief complaint of hypoalbuminemia, which occurs due to plasma protein leakage in the gastrointestinal tract, leading to general edema, ascites, and pleural effusions. CASE PRESENTATION: A 71-year-old woman visited another hospital for evaluation of hypoalbuminemia and systemic edema. She was hospitalized for a close inspection of hypoalbuminemia and was diagnosed with PLGE. Steroid and azathioprine therapy was prescribed; however, hypoalbuminemia did not improve, and the patient's condition worsened due to anasarca. As hospitalization was prolonged, the patient was transferred to our hospital. She was infected with Helicobacter pylori, and we performed H. pylori eradication. Following H. pylori eradication, her edema improved remarkably. CONCLUSION: We present the first case wherein H. pylori eradication successfully improved protein leakage in the lower gastrointestinal tract in a patient diagnosed with PLGE complicated with refractory to immunosuppressant treatment. H. pylori eradication should be considered in patients with PLGE complicated with H. pylori infection, without specific endoscopic finding or refractory to immunosuppressants.


Asunto(s)
Antibacterianos , Infecciones por Helicobacter , Helicobacter pylori , Cirrosis Hepática Biliar , Enteropatías Perdedoras de Proteínas , Anciano , Antibacterianos/uso terapéutico , Proteínas Sanguíneas/metabolismo , Femenino , Infecciones por Helicobacter/sangre , Infecciones por Helicobacter/complicaciones , Infecciones por Helicobacter/diagnóstico , Infecciones por Helicobacter/tratamiento farmacológico , Helicobacter pylori/aislamiento & purificación , Humanos , Inmunosupresores/uso terapéutico , Cirrosis Hepática Biliar/sangre , Cirrosis Hepática Biliar/complicaciones , Cirrosis Hepática Biliar/microbiología , Enteropatías Perdedoras de Proteínas/sangre , Enteropatías Perdedoras de Proteínas/complicaciones , Enteropatías Perdedoras de Proteínas/tratamiento farmacológico , Enteropatías Perdedoras de Proteínas/microbiología
13.
PLoS One ; 11(1): e0147061, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26771875

RESUMEN

Autophagy acts as a host-defense system against pathogenic microorganisms such as Group A Streptococcus (GAS). Autophagy is a membrane-mediated degradation system that is regulated by intracellular membrane trafficking regulators, including small GTPase Rab proteins. Here, we identified Rab30 as a novel regulator of GAS-containing autophagosome-like vacuoles (GcAVs). We found that Rab30, a Golgi-resident Rab, was recruited to GcAVs in response to autophagy induction by GAS infection in epithelial cells. Rab30 recruitment was dependent upon its GTPase activity. In addition, the knockdown of Rab30 expression significantly reduced GcAV formation efficiency and impaired intracellular GAS degradation. Rab30 normally functions to maintain the structural integrity of the Golgi complex, but GcAV formation occurred even when the Golgi apparatus was disrupted. Although Rab30 also colocalized with a starvation-induced autophagosome, Rab30 was not required for autophagosome formation during starvation. These results suggest that Rab30 mediates autophagy against GAS independently of its normal cellular role in the structural maintenance of the Golgi apparatus, and autophagosome biogenesis during bacterial infection involves specific Rab GTPases.


Asunto(s)
Aparato de Golgi/enzimología , Fagosomas/metabolismo , Proteínas de Unión al GTP rab/metabolismo , Células HeLa , Humanos , Viabilidad Microbiana , Microscopía Fluorescente , Plásmidos/genética , Proteínas de Unión al GTP rab/genética
14.
Cell Microbiol ; 16(12): 1806-21, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25052408

RESUMEN

Autophagy plays a crucial role in host defence by facilitating the degradation of invading bacteria such as Group A Streptococcus (GAS). GAS-containing autophagosome-like vacuoles (GcAVs) form when GAS-targeting autophagic membranes entrap invading bacteria. However, the membrane origin and the precise molecular mechanism that underlies GcAV formation remain unclear. In this study, we found that Rab17 mediates the supply of membrane from recycling endosomes (REs) to GcAVs. We showed that GcAVs contain the RE marker transferrin receptor (TfR). Colocalization analyses demonstrated that Rab17 colocalized effectively with GcAV. Rab17 and TfR were visible as punctate structures attached to GcAVs and the Rab17-positive dots were recruited to the GAS-capturing membrane. Overexpression of Rab17 increased the TfR-positive GcAV content, whereas expression of the dominant-negative Rab17 form (Rab17 N132I) caused a decrease, thereby suggesting the involvement of Rab17 in RE-GcAV fusion. The efficiency of GcAV formation was lower in Rab17 N132I-overexpressing cells. Furthermore, knockdown of Rabex-5, the upstream activator of Rab17, reduced the GcAV formation efficiency. These results suggest that Rab17 and Rab17-mediated REs are involved in GcAV formation. This newly identified function of Rab17 in supplying membrane from REs to GcAVs demonstrates that RE functions as a primary membrane source during antibacterial autophagy.


Asunto(s)
Endosomas/metabolismo , Células Epiteliales/inmunología , Células Epiteliales/microbiología , Interacciones Huésped-Patógeno , Fagosomas/metabolismo , Streptococcus pyogenes/crecimiento & desarrollo , Proteínas de Unión al GTP rab/metabolismo , Autofagia , Factores de Intercambio de Guanina Nucleótido/metabolismo , Células HeLa , Humanos , Streptococcus pyogenes/inmunología
15.
J Dermatol Sci ; 29(2): 73-84, 2002 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12088607

RESUMEN

It is known that, in patients of allergic asthma and rhinitis, the late-phase reaction (LPR) occurs 6-12 h after allergen challenge, but there are few reports concerning cytokine production in the cutaneous LPR in atopic dermatitis (AD). We report here the results of our study on the relationship between the cutaneous LPR and the production of cytokines such as IL-4, IL-5, IL-2 and IFN-gamma by peripheral blood mononuclear cells (PBMC) of AD patients. We selected 29 pure AD patients with no history of atopic airway diseases who showed high serum IgE antibody against Dermatophagoides farinae and performed skin prick testing with three different antigens and observed the resultant cutaneous reactions in 23 of the AD patients. Furthermore, we measured the cytokine production by the cultured PBMC under the stimulation of the antigens and compared it with the results of the skin tests. 13 (57%) of these 23 AD patients demonstrated positive LPR in response to D. farinae, and the mean concentration of IL-5 produced by PBMC was higher in these LPR-positive AD patients compared to the LPR-negative ones. Additionally, we noticed that there was a positive correlation between the mean diameter of the erythema of LPR and the level of IL-5 production by PBMC in the LPR-positive patients. We suggest that there are at least two groups in AD patients, i.e. LPR-positive and LPR-negative ones. The observation of LPR can be an important and practical way to classify AD patients into subgroups, which may enable us to regard IL-5 or eosinophils as a target for treatment.


Asunto(s)
Dermatitis Atópica/fisiopatología , Glicoproteínas/inmunología , Inmunoglobulina E/sangre , Piel/fisiopatología , Adulto , Antígenos Dermatofagoides , Citocinas/biosíntesis , Dermatitis Atópica/diagnóstico , Femenino , Humanos , Hipersensibilidad Tardía/diagnóstico , Hipersensibilidad Tardía/fisiopatología , Hipersensibilidad Inmediata/diagnóstico , Hipersensibilidad Inmediata/fisiopatología , Interleucina-5/biosíntesis , Masculino , Monocitos/inmunología , Monocitos/metabolismo , Valores de Referencia , Pruebas Cutáneas , Células TH1/metabolismo , Células Th2/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...