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1.
Orv Hetil ; 164(17): 651-658, 2023 Apr 30.
Artículo en Húngaro | MEDLINE | ID: mdl-37120810

RESUMEN

INTRODUCTION: During COVID-19 pandemic, a high mortality rate (20-60%) of patients admitted to intensive care unit has been observed. Identification of risk factors can support the understanding of disease pathophysiology and the recognition of vulnerable patients, prognostication and selection of appropriate treatment. OBJECTIVE: Beyond characterisation of a local, critically ill COVID-19 population, analysis of the associations between demographic/clinical data and patient survival were investigated. METHOD: Retrospective, observational study has been performed by recording demographic, clinical data and outcome parameters on patients with severe respiratory insufficiency caused by COVID-19. RESULTS: 88 patients were enrolled. Median age was 65 years and 53% of patients were male, median BMI was 29 kg/m2. Noninvasive ventilation was used in 81%, endotracheal intubation in 45%, prone positioning in 59% of all cases. Vasopressor treatment was introduced in 44%, secondary bacterial infection was detected in 36% of all cases. Hospital survival rate was 41%. Risk factors for survival and the effect of evolving treatment protocols were analyzed with multivariable regression model. A better survival chance was associated to younger age, lower APACE II score and non-diabetic status. Effect of the treatment protocol was found to be significant (OR = 0.18 [95% CI: 0.04-0.76], p = 0.01976) after controlling for APACHE II, BMI, sex, two comorbidities and two pharmaceutical agents (tocilizumab, remdesivir). CONCLUSION: Survival rate was favourable if patients were younger, with lower APACHE II score and if non-diabetic. Low initial survival rate (15%) significantly improved (49%) in association with the protocol changes. We would like to facilitate Hungarian centres to publish their data and initiate a nationwide database to improve the management of severe COVID disease. Orv Hetil. 2023; 164(17): 651-658.


Asunto(s)
COVID-19 , Humanos , Masculino , Anciano , Femenino , COVID-19/terapia , Estudios Retrospectivos , SARS-CoV-2 , Pandemias , Unidades de Cuidados Intensivos
2.
Eur J Trauma Emerg Surg ; 48(2): 763-774, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33399876

RESUMEN

PURPOSE: Trauma is a leading cause of mortality, with major bleeding and trauma-induced coagulopathy (TIC) contributing to negative patient outcomes. Treatments for TIC include tranexamic acid (TXA), fresh frozen plasma (FFP), and coagulation factor concentrates (CFCs, e.g. prothrombin complex concentrates [PCCs] and fibrinogen concentrate [FCH]). Guidelines for TIC management vary across Europe and a clear definition of TIC is still lacking. METHODS: An advisory board involving European trauma experts was held on 02 February 2019, to discuss clinical experience in the management of trauma-related bleeding and recommendations from European guidelines, focusing on CFC use (mainly FCH). This review summarises the discussions, including TIC definitions, gaps in the guidelines that affect their implementation, and barriers to use of CFCs, with suggested solutions. RESULTS: A definition of TIC, which incorporates clinical (e.g. severe bleeding) and laboratory parameters (e.g. low fibrinogen) is suggested. TIC should be treated immediately with TXA and FCH/red blood cells; subsequently, if fibrinogen ≤ 1.5 g/L (or equivalent by viscoelastic testing), treatment with FCH, then PCC (if bleeding continues) is suggested. Fibrinogen concentrate, and not FFP, should be administered as first-line therapy for TIC. Several initiatives may improve TIC management, with improved medical education of major importance; generation of new and stronger data, simplified clinical practice guidance, and improved access to viscoelastic testing are also critical factors. CONCLUSIONS: Management of TIC is challenging. A standard definition of TIC, together with initiatives to facilitate effective CFC administration, may contribute to improved patient care and outcomes.


Asunto(s)
Trastornos de la Coagulación Sanguínea , Hemostáticos , Ácido Tranexámico , Trastornos de la Coagulación Sanguínea/terapia , Factores de Coagulación Sanguínea/farmacología , Factores de Coagulación Sanguínea/uso terapéutico , Fibrinógeno/uso terapéutico , Hemorragia/tratamiento farmacológico , Hemorragia/etiología , Hemostáticos/uso terapéutico , Humanos , Ácido Tranexámico/uso terapéutico
3.
Injury ; 52 Suppl 1: S15-S20, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33436265

RESUMEN

INTRODUCTION: Bleeding and coagulopathy are leading causes of morbidity and lethal outcome after multiple injuries. The pathophysiology of traumatic coagulopathy is under extensive investigations and recent results highlighted the central role of fibrinogen and the fibrin polymerisation process. Our goal was to investigate the factors influencing fibrinogen level and the consequences of hypofibrinogenaemia with clinical importance. METHODS: We conducted a retrospective analysis enrolling adult patients admitted to the shock room of a tertiary trauma centre in Hungary. Beside coagulation values, demographic data, injury related, transfusion and outcome parameters were collected from the hospital electronic charts. Only patients with complete e-chart were involved into final analysis. Multivariate linear and proportional odds logistic regression models were used to model outcomes - admission fibrinogen and SOFA score - controlling for age, sex, BMI, ISS and lactic acidosis. RESULTS: 54 patients were enrolled in final analysis. Among the parameters analysed, BMI was positively associated with fibrinogen level at admission (+0.23 g/l for every 5 unit of increase in BMI, 95% CI: 0.09-0.37, p=0.0021). Increased risk of transfusion was observed, if fibrinogen at admission was about 1.8 g/l or lower. Beside age and ISS, fibrinogen concentration was also a determinant of early organ failures as it negatively correlated with SOFA scores within 24 hours or care (OR=2.42, 95% CI: 1.05-5.62, for 1 g/l decrease, p=0.0388). CONCLUSIONS: In our trauma cohort BMI seems to significantly influence fibrinogen level at admission. This result draws our attention to the possible differences of haemostasis process, and consequently different diagnostic and therapeutic thresholds in the management of obese trauma patients. Moderate hypofibrinogenaemia increases transfusion risk and beside ISS might be a prognostic factor of early MOF after multiple injuries.


Asunto(s)
Traumatismo Múltiple , Heridas y Lesiones , Adulto , Índice de Masa Corporal , Fibrinógeno , Hospitales , Humanos , Puntaje de Gravedad del Traumatismo , Insuficiencia Multiorgánica/etiología , Estudios Retrospectivos , Heridas y Lesiones/complicaciones , Heridas y Lesiones/terapia
4.
Adv Orthop ; 2021: 2235600, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34631171

RESUMEN

Perioperative transfusion in patients undergoing orthopedic surgery increases the number of postoperative complications. Thus, we have introduced an institution-tailored perioperative blood management program (PBM) to decrease the amount of blood transfused in patients going through primary total hip replacement (THR) surgery. We have conducted a before-after observational cohort study in two predetermined observational periods. Demographic and clinical data, ASA scores, laboratory parameters, features of surgical procedure, and anesthesia were registered. Parameters of perioperative fluid administration, transfusion rate, and postoperative complications were also assessed. One hundred patients in the first and 108 patients in the second observational period were enrolled. Eventhough the ratio of posttraumatic THR procedures increased (9% vs. 17%), the PBM protocol has been utilized effectively and a significant decrease in perioperative blood transfusion rate has been observed (61% vs. 21%). The abolishment of routine preoperative LMWH prophylaxis (90% vs. 16%), intraoperative use of tranexamic acid (10% vs. 84%), and the encouraged exploitation of our postoperative observational facility (5% vs. 39%) were abided by our colleagues. Patients still requiring transfusion had lower preoperative hemoglobin levels (129 vs. 147 g/l), scored higher in ASA (ASA III: 46% vs. 19%), and more often presented postoperative hypotension (40% vs. 7%), oliguria (23% vs. 5%), and infections (9% vs. 2%). We conclude that the individualized perioperative blood management protocol was successfully implemented and yielded a lower transfusion rate and better outcomes. Our study suggests that a partial, institution-tailored PBM program may be suitable and beneficial in countries where the modalities of perioperative blood management are limited.

5.
Scand J Trauma Resusc Emerg Med ; 29(1): 158, 2021 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-34727955

RESUMEN

BACKGROUND: We leveraged the data of the international CREACTIVE consortium to investigate whether the outcome of traumatic brain injury (TBI) patients admitted to intensive care units (ICU) in hospitals without on-site neurosurgical capabilities (no-NSH) would differ had the same patients been admitted to ICUs in hospitals with neurosurgical capabilities (NSH). METHODS: The CREACTIVE observational study enrolled more than 8000 patients from 83 ICUs. Adult TBI patients admitted to no-NSH ICUs within 48 h of trauma were propensity-score matched 1:3 with patients admitted to NSH ICUs. The primary outcome was the 6-month extended Glasgow Outcome Scale (GOS-E), while secondary outcomes were ICU and hospital mortality. RESULTS: A total of 232 patients, less than 5% of the eligible cohort, were admitted to no-NSH ICUs. Each of them was matched to 3 NSH patients, leading to a study sample of 928 TBI patients where the no-NSH and NSH groups were well-balanced with respect to all of the variables included into the propensity score. Patients admitted to no-NSH ICUs experienced significantly higher ICU and in-hospital mortality. Compared to the matched NSH ICU admissions, their 6-month GOS-E scores showed a significantly higher prevalence of upper good recovery for cases with mild TBI and low expected mortality risk at admission, along with a progressively higher incidence of poor outcomes with increased TBI severity and mortality risk. CONCLUSIONS: In our study, centralization of TBI patients significantly impacted short- and long-term outcomes. For TBI patients admitted to no-NSH centers, our results suggest that the least critically ill can effectively be managed in centers without neurosurgical capabilities. Conversely, the most complex patients would benefit from being treated in high-volume, neuro-oriented ICUs.


Asunto(s)
Lesiones Traumáticas del Encéfalo , Neurocirugia , Adulto , Escala de Coma de Glasgow , Escala de Consecuencias de Glasgow , Hospitales , Humanos , Unidades de Cuidados Intensivos
6.
Bull Emerg Trauma ; 4(1): 48-50, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27162927

RESUMEN

Advanced Trauma Life Support (ATLS) programs are recognized as the standard educational trauma program worldwide. Data suggest that ATLS has a positive impact on the value of trauma care. The ATLS Hungary program has been started in 2005, celebrating its 10-year anniversary this year. In the present brief communication a brief overview is provided on the program.Student evaluation and statistical data about the participants were collected throughout the 10-year history of the Hungarian program.Student evaluation shows a high level of satisfaction amongst the participating doctors. Most participants are working in higher level centers. The Hungarian program shows good quality according to the participants. Establishing at least one new center is crucial to be able to provide the course for every professional interested in it or required to take it.

7.
Biochem J ; 383(Pt 1): 165-70, 2004 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-15250825

RESUMEN

UK114, the goat liver tumour antigen, is a member of a widely distributed family of conserved low-molecular-mass proteins (YER057c/YjgF/UK114), the function of which is ill understood. To the various orthologues diverse functions have been ascribed, such as translation inhibition, regulation of purine repressor or calpain activation. Owing to a limited sequence similarity to Hsp90 (heat-shock protein 90), they have also been proposed to be molecular chaperones; however, this has never been tested. In the present paper, we report the cloning and characterization of the Drosophila orthologue, DUK114. In brief, DUK114 had no effect that would have qualified it as a calpain activator. In contrast, it proved to be a very potent molecular chaperone in in vitro assays. In a heat-aggregation test, it significantly decelerated the formation of citrate synthase aggregates. In a reverse assay, the recovery of the enzyme from urea- and heat-induced denatured states was accelerated almost 3-fold. On a molar basis, the chaperone activity of the 15-kDa DUK114 is comparable with that of Hsp90, the almost 6-times-larger archetypal molecular chaperone. In similar assays, DUK114 was ineffective with Drosophila calpain A or calpain B. To test for its chaperone activity in vivo, DUK114 was transfected into Schneider (S2) cells; after heat shock, the number of viable non-transfected cells started to increase after a lag time; in the presence of DUK114, cell proliferation started at once. Our work is the first experimental evidence that DUK114, and possibly other members of this family, are molecular chaperones.


Asunto(s)
Chaperonas Moleculares/fisiología , Secuencia de Aminoácidos , Animales , Calpaína/química , Calpaína/fisiología , Bovinos , Línea Celular , Citrato (si)-Sintasa/metabolismo , Clonación Molecular , Proteínas de Drosophila/biosíntesis , Proteínas de Drosophila/química , Proteínas de Drosophila/fisiología , Drosophila melanogaster , Calor , Proteínas de la Membrana/química , Chaperonas Moleculares/biosíntesis , Chaperonas Moleculares/química , Datos de Secuencia Molecular , Conformación Proteica , Desnaturalización Proteica , Renaturación de Proteína , Proteínas Recombinantes de Fusión/biosíntesis , Homología de Secuencia de Aminoácido
8.
Immunol Lett ; 92(1-2): 157-61, 2004 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-15081540

RESUMEN

Molecular chaperones (heat shock proteins, Hsp-s) play a pleiotropic role in immunological functions. Hsp-s participate in the presentation of peptide antigens, folding of several immunologically important proteins, such as the MHC, and in the maintenance of the activation-competent conformation of key signaling molecules (mostly serine/threonine and tyrosine kinases) of B and T cells activation. The most abundant cytoplasmic chaperone, Hsp90, is in the center of these processes. In recent years Hsp90 inhibitors emerged as very promising anticancer agents. Not surprisingly, Hsp90 inhibitors behave as immunosuppressants, and also cause an induction of superoxide production. Here we extend our previous data by showing the enhancement of complement-induced lysis of several types of tumor cells after Hsp90 inhibition. This novel mechanism may significantly contribute to the anticancer effects of Hsp90 inhibitors in vivo.


Asunto(s)
Proteínas del Sistema Complemento/fisiología , Proteínas HSP90 de Choque Térmico/antagonistas & inhibidores , Neoplasias/prevención & control , Antineoplásicos/farmacología , Proteínas del Sistema Complemento/inmunología , Humanos , Inmunidad Celular/efectos de los fármacos , Inmunidad Celular/inmunología , Inmunosupresores/farmacología , Células Jurkat , Neoplasias/tratamiento farmacológico , Superóxidos/inmunología , Superóxidos/metabolismo
9.
Exp Gerontol ; 37(10-11): 1257-62, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12470839

RESUMEN

Chaperones have an important role in the repair of proteotoxic damage, which is greatly increased in aged subjects. Chaperone levels and expression were subject of numerous studies in aged organisms. However, there were only very few attempts to measure chaperone activity in aged animals. Here, we report our initial studies showing a decreased chaperone capacity of liver cytosol from aged rats compared to those of young counterparts. The amount of Hsc70/Hsp70 was not significantly different in livers of young and aged rats. On the contrary, old animals showed a significant decrease in their hepatic Hsp90 content, which may explain their decreased chaperone activity. The observed decrease in chaperone capacity may also reflect a direct proteotoxic damage of chaperones, or an increase in chaperone occupancy, i.e. a 'chaperone overload' due to the increased amount of damaged hepatic proteins in aged rats. Experiments are in progress to elucidate the mechanism of the observed age-induced changes in chaperone function.


Asunto(s)
Envejecimiento/metabolismo , Hígado/metabolismo , Chaperonas Moleculares/fisiología , Animales , Citosol/metabolismo , Luciferasas/metabolismo , Desnaturalización Proteica/fisiología , Ratas , Ratas Wistar
10.
Biofactors ; 17(1-4): 249-57, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-12897446

RESUMEN

Protection against oxidative stress is highly interrelated with the function of the most ancient cellular defense system, the network of molecular chaperones, heat shock, or stress-proteins. These ubiquitous, conserved proteins help other proteins and macromolecules to fold or re-fold and reach their final, native conformation. Redox regulation of protein folding becomes especially important during the preparation of extracellular proteins to the outside oxidative milieu, which should take place in a gradual and step-by-step controlled manner in the endoplasmic reticulum or in the periplasm. Several chaperones, such as members of the Hsp33 family in yeast and the plethora of small heat shock proteins as well as one of the major chaperones, Hsp70 are able to act against cytoplasmic oxidative damage. Abrupt changes of cellular redox status lead to chaperone induction. The function of several chaperones is tightly regulated by the surrounding redox conditions. Moreover, our recent data suggest that chaperones may act as a central switchboard for the transmission of redox changes in the life of the cell.


Asunto(s)
Proteínas de Choque Térmico , Homeostasis , Chaperonas Moleculares , Oxidación-Reducción , Envejecimiento , Animales , Supervivencia Celular , Citoplasma/química , Enfermedad , Retículo Endoplásmico/química , Proteínas de Choque Térmico/química , Proteínas de Choque Térmico/fisiología , Humanos , Chaperonas Moleculares/química , Chaperonas Moleculares/fisiología , Estrés Oxidativo , Pliegue de Proteína
11.
Biofactors ; 17(1-4): 259-67, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-12897447

RESUMEN

The endoplasmic reticulum (ER), similary to other subcompartments of the eukaryotic cell possesses a relatively oxidizing environment. The special milieu of ER lumen is important for many ER-specific processes (redox protein folding, glycoprotein synthesis, quality control of secreted proteins, antigen presentation, etc.). Despite of the vital importance of redox regulation in the ER, we have a surprisingly fragmented knowledge about the mechanisms responsible for the ER redox balance. Moreover, new observations on disulfide bridge synthesis and on glutathione functions urge us to revise our recent theories based on many indirect and in vitro results. We have also very little information about the effects of different pathological conditions on the thiol metabolism and redox folding in the ER. Examining the role of molecular chaperones in the cellular pathology of diabetes mellitus we found that the ER redox environment shifted to a more reducing state, which was followed by changes of the thiol metabolism and structural-functional changes of the protein machinery involved in the redox folding process in diabetes. The possible consequences of these unexpected changes are also discussed.


Asunto(s)
Diabetes Mellitus , Retículo Endoplásmico/química , Oxidación-Reducción , Estrés Oxidativo , Animales , Disulfuros/química , Retículo Endoplásmico/metabolismo , Humanos , Proteínas de la Membrana/química , Proteína Disulfuro Isomerasas/química , Proteína Disulfuro Isomerasas/metabolismo , Pliegue de Proteína , Compuestos de Sulfhidrilo/química , Compuestos de Sulfhidrilo/metabolismo
12.
Orv Hetil ; 144(13): 605-11, 2003 Mar 30.
Artículo en Húngaro | MEDLINE | ID: mdl-12728785

RESUMEN

Stress proteins or in other words heat shock proteins form an ancient defense system of our cells. They are necessary to prevent the aggregation of damaged proteins and to help their refolding after stress. Stress protein-assisted remodeling of protein structure is an important step of many cellular processes, such as protein transport, signaling and protein degradation. Stress proteins have a key role in many diseases. Thus they 1. protect our cells against the deteriorating effects of ischemia/reperfusion in myocardiac infarcts or in stroke; 2. protect transplanted tissues and organs; 3. act against the multiple damage of chronic diseases such as diabetes, or neurodegenerative diseases (Alzheimer's and Parkinson's disease); 4. participate in the etiology of several autoimmune diseases; 5. their activation, and role in antigen presentation can be used as an anticancer-therapy; 6. stress proteins increase longevity, and lastly 7. stress proteins act as a buffer of phenotypically silent mutations and may contribute to the onset of "civilizational diseases" (cancer, atherosclerosis, diabetes, etc.). In this review the authors also summarize the existing stress protein-related pharmacological approaches to cure a large variety of diseases.


Asunto(s)
Proteínas de Choque Térmico/metabolismo , Envejecimiento , Animales , Enfermedades Autoinmunes/metabolismo , Humanos , Chaperonas Moleculares/metabolismo , Infarto del Miocardio/metabolismo , Neoplasias/metabolismo , Enfermedades Neurodegenerativas/metabolismo , Trasplante de Tejidos
13.
Trends Immunol ; 27(2): 74-9, 2006 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16364688

RESUMEN

Molecular chaperones (heat shock proteins) are important components of cellular networks, such as protein-protein and gene regulatory networks. Chaperones participate in the folding of immunologically important proteins, presentation of antigens and activation of the immune system. Here, we propose that chaperone-related immune dysfunction might be more general than was previously thought. Mutations and polymorphism of chaperones and the regulators of their synthesis, heat shock factor-1, chaperone diseases, sick chaperones and chaperone overload might all affect (mostly impairing) immune responses.


Asunto(s)
Chaperonas Moleculares/inmunología , Chaperonas Moleculares/metabolismo , Animales , Humanos , Chaperonas Moleculares/genética , Mutación/genética , Polimorfismo Genético/genética , Unión Proteica
14.
Biochem Biophys Res Commun ; 338(2): 938-45, 2005 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-16246310

RESUMEN

The molecular steps of the electron transfer in the endoplasmic reticulum from the secreted proteins during their oxidation are relatively unknown. We present here that flavine adenine dinucleotide (FAD) is a powerful oxidizer of the oxidoreductase system, Ero1 and PDI, besides the proteins of rat liver microsomes and HepG2 hepatoma cells. Inhibition of FAD transport hindered the action of FAD. Microsomal membrane integrity was mandatory for all FAD-related oxidation steps downstream of Ero1. The PDI inhibitor bacitracin could inhibit FAD-mediated oxidation of microsomal proteins and PDI, but did not hinder the FAD-driven oxidation of Ero1. Our data demonstrated that Ero1 can utilize FAD as an electron acceptor and that FAD-driven protein oxidation goes through the Ero1-PDI pathway and requires the integrity of the endoplasmic reticulum membrane. Our findings prompt further studies to elucidate the membrane-dependent steps of PDI oxidation and the role of FAD in redox folding.


Asunto(s)
Membrana Celular/metabolismo , Proteínas del Complejo de Cadena de Transporte de Electrón/metabolismo , Retículo Endoplásmico/metabolismo , Flavina-Adenina Dinucleótido/administración & dosificación , Glicoproteínas/metabolismo , Microsomas Hepáticos/metabolismo , Proteína Disulfuro Isomerasas/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Animales , Membrana Celular/ultraestructura , Células Cultivadas , Relación Dosis-Respuesta a Droga , Retículo Endoplásmico/ultraestructura , Humanos , Masculino , Oxidación-Reducción , Oxidorreductasas actuantes sobre Donantes de Grupos Sulfuro , Ratas , Ratas Sprague-Dawley
15.
Biochem Biophys Res Commun ; 334(3): 787-95, 2005 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-16023999

RESUMEN

Changes in assisted protein folding are largely unexplored in diabetes. In the present studies, we have identified a reductive shift in the redox status of rat liver microsomes after 4 weeks of streptozotocin-induced diabetes. This change was reflected by a significant increase in the total- and protein-sulfhydryl content, as well as in the free sulfhydryl groups of the major protein disulfide isomerases (PDIs), the 58 kDa PDI and the 57 kDa ERp57 but not other chaperones. A parallel decrease of the protein-disulfide oxidoreductase activity was detected in the microsomal fraction of diabetic livers. The oxidant of PDI, Ero1-Lalpha showed a more oxidized status in diabetic rats. Our results reveal major changes in the redox status of the endoplasmic reticulum and its redox chaperones in diabetic rats, which may contribute to the defective protein secretion of the diabetic liver.


Asunto(s)
Diabetes Mellitus Experimental/metabolismo , Microsomas Hepáticos/metabolismo , Pliegue de Proteína , Animales , Ácido Ascórbico/metabolismo , Ácido Deshidroascórbico/metabolismo , Flavina-Adenina Dinucleótido/metabolismo , Disulfuro de Glutatión/metabolismo , Masculino , NADH NADPH Oxidorreductasas/biosíntesis , Oxidación-Reducción , Proteína Disulfuro Isomerasas/biosíntesis , Ratas , Ratas Wistar
16.
J Biol Chem ; 279(5): 3370-4, 2004 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-14612450

RESUMEN

The transport of FAD and its effect on disulfide bond formation was investigated in rat liver microsomal vesicles. By measuring the intravesicular FAD-accessible space, we observed that FAD permeates across the microsomal membrane and accumulates in the lumen. Rapid filtration experiments also demonstrated the uptake and efflux of the compound, which could be inhibited by atractyloside and 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid. FAD entering the lumen promoted the oxidation of protein thiols and increased the intraluminal oxidation of glucose-6-phosphate. These findings support the notion that, similar to yeast, free FAD may have a decisive role in the mechanism of oxidative protein folding in the endoplasmic reticulum lumen of mammalian cells.


Asunto(s)
Flavina-Adenina Dinucleótido/química , Microsomas Hepáticos/metabolismo , Ácido 4,4'-Diisotiocianostilbeno-2,2'-Disulfónico/farmacología , Animales , Atractilósido/farmacología , Transporte Biológico , Citosol/metabolismo , Disulfuros , Relación Dosis-Respuesta a Droga , Retículo Endoplásmico/metabolismo , Membranas Intracelulares/metabolismo , Masculino , Oxígeno/metabolismo , Unión Proteica , Ratas , Ratas Sprague-Dawley , Compuestos de Sulfhidrilo/química , Compuestos de Sulfhidrilo/metabolismo , Factores de Tiempo
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