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1.
Amino Acids ; 50(5): 569-576, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29392418

RESUMEN

In this study, an acute overloading of methionine (MetLo) was used to investigate the trassulfuration pathway response comparing healthy controls and HIV+ patients under their usual diet and dietary N-acetyl-L-cysteine (NAC) supplementation. MetLo (0.1 g Met/kg mass weight) was given after overnight fasting to 20 non-HIV+ control subjects (Co) and 12 HIV+ HAART-treated patients. Blood samples were taken before and after the MetLo in two different 7-day dietary situations, with NAC (1 g/day) or with their usual diet (UD). The amino acids (Met, Hcy, Cys, Tau, Ser, Glu and Gln) and GSH were determined by HPLC and their inflow rate into circulation (plasma) was estimated by the area under the curve (AUC). Under UD, the HIV+ had lower plasma GSH and amino acids (excepting Hcy) and higher oxidative stress (GSSG/GSH ratio), similar remethylation (RM: Me/Hcy + Ser ratio), transmethylation (TM; Hcy/Met ratio) and glutaminogenesis (Glu/Gln ratio), lower transsulfuration (TS: Cys/Hcy + Ser ratio) and Cys/Met ratio and, higher synthetic rates of glutathione (GG: GSH/Cys ratio) and Tau (TG: Tau/Cys ratio). NAC supplementation changed the HIV pattern by increasing RM above control, normalizing plasma Met and TS and, increasing plasma GSH and GG above controls. However, plasma Cys was kept always below controls probably, associatively to its higher consumption in GG (more GSSG than GSH) and TG. The failure of restoring normal Cys by MetLo, in addition to NAC, in HIV+ patients seems to be related to increased flux of Cys into GSH and Tau pathways, probably strengthening the cell-antioxidant capacity against the HIV progression (registered at http://www.clinicaltrials.gov , NCT00910442).


Asunto(s)
Acetilcisteína/administración & dosificación , Cisteína/sangre , Suplementos Dietéticos , Glutatión/sangre , Infecciones por VIH , VIH-1 , Metionina/sangre , Adulto , Terapia Antirretroviral Altamente Activa , Femenino , Infecciones por VIH/sangre , Infecciones por VIH/terapia , Humanos , Masculino , Persona de Mediana Edad
2.
J Surg Res ; 188(2): 473-9, 2014 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-24582214

RESUMEN

BACKGROUND: Mitochondrial dysfunction has been closely related to many pathologic processes, such as cellular apoptosis. Alterations in organelle membrane potential are associated with mitochondrial dysfunction. A fluorine-18 labeled phosphonium compound: (18)F-triphenylphosphonium ((18)F-TPP) was prepared to determine its potential use as a mitochondria-targeting radiopharmaceutical to evaluate cellular apoptosis. METHODS: Studies were conducted in both ex vivo cell lines and in vivo using a burned animal model. Uptake of (18)F-TPP was assessed in PC-3 cells by gamma counting under the following conditions: graded levels of extracellular potassium concentrations, incubation with carbonyl cyanide m-chlorophenylhydrazone and staurosporine. Apoptosis was studied in a burn animal model using terminal deoxynucleotidyl transferase dUTP nick end labeling staining and simultaneous assessment of (18)F-TPP uptake by biodistribution. RESULTS: We found that stepwise membrane depolarization by potassium (K) resulted in a linear decrease in (18)F-TPP uptake, with a slope of 0.62 ± 0.08 and a correlation coefficient of 0.936 ± 0.11. Gradually increased concentrations of m-chlorophenylhydrazone lead to decreased uptake of (18)F-TPP. Staurosporine significantly decreased the uptake of (18)F-TPP in PC-3 cells from 14.2 ± 3.8% to 5.6 ± 1.3% (P < 0.001). Burn-induced significant apoptosis (sham: 4.4 ± 1.8% versus burn: 24.6 ± 6.7 %; P < 0.005) and a reduced uptake of tracer in the spleens of burn-injured animals as compared with sham burn controls (burn: 1.13 ± 0.24% versus sham: 3.28 ± 0.67%; P < 0.005). Biodistribution studies demonstrated that burn-induced significant reduction in (18)F-TPP uptake in spleen, heart, lung, and liver, which were associated with significantly increased apoptosis. CONCLUSIONS: (18)F-TPP is a promising new voltage sensor for detecting mitochondrial dysfunction and apoptosis in various tissues.


Asunto(s)
Apoptosis , Quemaduras/diagnóstico por imagen , Radioisótopos de Flúor , Potencial de la Membrana Mitocondrial , Compuestos Organofosforados/uso terapéutico , Animales , Carbonil Cianuro m-Clorofenil Hidrazona , Línea Celular Tumoral , Evaluación Preclínica de Medicamentos , Humanos , Ratones , Ratones Endogámicos C57BL , Tomografía de Emisión de Positrones , Potasio , Bazo/diagnóstico por imagen , Estaurosporina , Valinomicina
3.
J Pharmacol Exp Ther ; 339(3): 832-41, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21873557

RESUMEN

Treatment with statins, inhibitors of HMG-CoA reductase, extends the survival of septic mice. However, the molecular mechanisms underlying the cholesterol-lowering, independent beneficial effects of statins in sepsis are poorly understood. The inhibition of protein isoprenylation, namely farnesylation and geranylgeranylation, has been proposed as a mediator of the pleiotropic protective effects of statins, although direct evidence is lacking. Major features of sepsis-induced immune suppression include T-cell dysfunction, which is characterized by apoptosis of splenic T cells, increased CD4(+)Foxp3(+) regulatory T cells (Tregs), and suppression of type 1 helper T-cell response [e.g., interferon-γ (IFN-γ) secretion] in mice. Here, we show that the induction of sepsis by cecal ligation and puncture (CLP) resulted in increases in farnesyltransferase activity and farnesylated proteins in the spleen relative to sham operation. Treatment with farnesyltransferase inhibitor N-[4-[2(R)-amino-3-mercaptopropyl]amino-2-phenylbenzoyl]methionine methyl ester trifluoroacetate salt (FTI-277) (25 mg/kg b.wt. i.p.) at 2 h after CLP blocked the increase in farnesylated proteins and improved survival and bacterial clearance of septic mice. FTI-277 reverted to or mitigated sepsis-induced apoptosis in spleen and thymus, increased splenic CD4(+)Foxp3(+) Tregs, and suppressed IFN-γ secretion and proliferation of splenocytes in response to anti-CD3+CD28 antibodies in mice. Moreover, FTI-277 promoted macrophage phagocytotic activity in septic mice. These results indicate that elevation in protein farnesylation plays a role in derangements in immune function and mortality of septic mice. These findings suggest that prevention of immune dysfunction might contribute to FTI-277-induced improvement in survival of septic mice. These data highlight protein farnesyltransferase as a novel potential molecular target to reduce the mortality of patients with sepsis.


Asunto(s)
Carga Bacteriana/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Farnesiltransferasa/antagonistas & inhibidores , Metionina/análogos & derivados , Sepsis/tratamiento farmacológico , Animales , Ciego/cirugía , Citocinas/análisis , Evaluación Preclínica de Medicamentos , Farnesiltransferasa/metabolismo , Proteína HMGB1/sangre , Pruebas de Función Cardíaca , Hemodinámica/efectos de los fármacos , Pulmón/efectos de los fármacos , Masculino , Metionina/farmacología , Ratones , Ratones Endogámicos C57BL , Prenilación de Proteína , Sepsis/inmunología , Sepsis/mortalidad , Bazo/efectos de los fármacos , Bazo/metabolismo , Linfocitos T/efectos de los fármacos
4.
Shock ; 28(4): 477-83, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17558346

RESUMEN

Thermal injury results in reduced plasma levels of arginine (Arg). With reduced Arg availability, NOS produces superoxide instead of NO. We hypothesized that Arg supplementation after burn and smoke inhalation (B + S) injury would attenuate the acute insult to the lungs and, thus, protect pulmonary function. Seventeen Suffolk ewes (n = 17) were randomly divided into three groups: (1) sham injury group (n = 6), (2) B + S injury plus saline treatment (n = 6), and (3) B + S injury plus L-ARG infusion at 57 mg.kg(-1).h(-1) (n = 5). Burn and smoke inhalation injury was induced by standardized procedures, including a 40% area full thickness flame burn combined with 48 breaths of smoke from burning cottons. All animals were immediately resuscitated by Ringer solution and supported by mechanical ventilation for 48 h, during which various variables of pulmonary function were monitored. The results demonstrated that Arg treatment attenuated the decline of plasma Arg concentration after B + S injury. A higher plasma Arg concentration was associated with a less decline in Pao2/Fio2 ratio and a reduced extent of airway obstruction after B + S injury. Histopathological examinations also indicated a remarkably reduced histopathological scores associated with B + S injury. Nitrotyrosine stain in lung tissue was positive after B + S injury, but was significantly reduced in the group with Arg. Therefore, L-Arg supplementation improved gas exchange and pulmonary function in ovine after B + S injury via its, at least in part, effect on reduction of oxidative stress through the peroxynitrite pathway.


Asunto(s)
Arginina/farmacología , Quemaduras/tratamiento farmacológico , Pulmón/efectos de los fármacos , Lesión por Inhalación de Humo/tratamiento farmacológico , Obstrucción de las Vías Aéreas/metabolismo , Obstrucción de las Vías Aéreas/patología , Obstrucción de las Vías Aéreas/prevención & control , Animales , Arginina/sangre , Presión Sanguínea/efectos de los fármacos , Quemaduras/patología , Quemaduras/fisiopatología , Femenino , Hematócrito , Lesión Pulmonar , Nitratos/sangre , Nitritos/sangre , Distribución Aleatoria , Ovinos , Lesión por Inhalación de Humo/patología , Lesión por Inhalación de Humo/fisiopatología , Análisis de Supervivencia , Tirosina/análogos & derivados , Tirosina/metabolismo , Micción/efectos de los fármacos
5.
Surgery ; 135(6): 671-8, 2004 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15179374

RESUMEN

OBJECTIVE: Glutamine is a nonessential amino acid that, in recent years, has been found to play important roles in several metabolic and immunologic processes. It has been theorized that, in a stressed state, it may become "conditionally essential" because the patient's ability to manufacture glutamine may not be adequate to meet their needs under this condition. We chose to evaluate the ability of 48 hours of enteral glutamine to enhance immediate nitrogen accretion in stressed pediatric burn patients. METHODS: Nine children with serious burns who were tolerating tube feedings were enrolled in a human studies committee-approved protocol in which they received 48 hours of enteral feedings with glutamine replacing 20% of essential and nonessential amino acids and 48 hours of isonitrogenous, isocaloric standard enteral feedings. This interval was chosen to help ensure that the study periods were comparable from a metabolic perspective. At the end of each period, protein kinetics were determined by a primed constant infusion of L-[1-(13)C] leucine tracer. The order of the studies was randomized. Seven children completed both phases of the study. Results were compared by paired t test and are presented as mean +/- standard error of the mean. RESULTS: During the glutamine feeding period, the leucine flux and leucine oxidation rate were significantly lower than those in the conventional feeding period. This reflects a reduction in total leucine intake from 80 +/- 11 to 62 +/- 10 micromol/kg per hour. However, there was no significant difference in the net balance of leucine accretion into proteins between these 2 dietary periods, which indicated that enriched glutamine feeding for 48 hours did not result in an immediate whole body protein gain in this group of pediatric patients. In addition, plasma glutamine concentration showed a moderate increase after 48 hours of supplementation but did not reach significance. CONCLUSION: Rapid protein accretion does not occur with short-term enteral glutamine supplementation. Several days of glutamine supplementation may be required to restore plasma glutamine levels and stimulate protein synthesis.


Asunto(s)
Quemaduras/metabolismo , Quemaduras/terapia , Suplementos Dietéticos , Nutrición Enteral , Glutamina/administración & dosificación , Proteínas/metabolismo , Adolescente , Isótopos de Carbono , Niño , Preescolar , Esquema de Medicación , Femenino , Glutamina/sangre , Humanos , Lactante , Cinética , Leucina/metabolismo , Masculino , Nitrógeno/metabolismo , Oxidación-Reducción , Estrés Fisiológico/metabolismo , Estrés Fisiológico/terapia , Resultado del Tratamiento
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