Estudio comparativo de melatonina contra los tratamientos inmunomoduladores (interferón beta y acetato de glatirámero) en un modelo murino de esclerosis múltiple / A comparative study of melatonin and immunomodulatory therapy with interferon beta and glatiramer acetate in a mouse model of multiple sclerosis

Introducción: La esclerosis múltiple (EM) es una enfermedad crónica desmielinizante autoinmune del sistema nervioso central (SNC) que produce neuroinflamación; un modelo es la encefalitis autoinmune experimental (EAE). La EM ha sido tratada con interferón beta (IFN-β) y acetato de glatirámero (AG). Se ha descrito que la melatonina (MLT) modula la respuesta del sistema inmune. El objetivo de este estudio fue observar el efecto de la administración de MLT contra los tratamientos de primera línea utilizados en la EM (IFN-β y AG).MétodosSe indujo EAE a ratas macho Sprague Dawley y se les administró IFN-β, AG o MLT. Se colectó líquido cefalorraquídeo (LCR) y se midieron citocinas proinflamatorias por multiplex, además del registro de la evaluación neurológica de la EAE.ResultadosTodos los animales inmunizados establecieron la EAE. Se evaluó el primer ciclo de recaída-remisión, observando que IFN-β y AG tienen mejores resultados que MLT en la evaluación clínica. La concentración en el LCR tanto de IL-1β como de IL-12p70 no se vio modificada por el modelo o por los tratamientos administrados. EL TNF-α se vio disminuido en el LCR por el IFN-β y la MLT bajo el modelo de EM.ConclusionesEs necesario realizar estudios posteriores para evaluar los mecanismos moleculares involucrados en el comportamiento de la MLT en la EAE, así como la cuantificación de otras citocinas en diferentes matrices biológicas para poder considerar la MLT como un agente antiinflamatorio regulador de la EM. (AU)

Introduction: Multiple sclerosis (MS) is a chronic, demyelinating, autoimmune disease of the central nervous system causing neuroinflammation. Experimental autoimmune encephalitis (EAE) is a model of the disease. MS is classically treated with interferon beta (IFN-β) and glatiramer acetate (GA). Melatonin (MLT) has been reported to modulate immune system responses. The aim of the present study is to analyse the effects of MLT administration in comparison with the first-line treatments for MS (IFN-β and GA).MethodsEAE was induced in male Sprague-Dawley rats; the animals subsequently received either IFN-β, GA, or MLT. Cerebrospinal fluid (CSF) samples were analysed by multiplex assay to determine the levels of proinflammatory cytokines. The neurological evaluation of EAE was also recorded.ResultsAll immunised animals developed EAE. We evaluated the first relapse-remission cycle, observing that IFN-β and GA had better results than MLT in the clinical evaluation. Neither EAE nor any of the treatments administered modified CSF IL-1β and IL-12p70 concentrations. However, IFN-β and MLT did decrease CSF TNF-α concentrations.ConclusionsFurther studies are needed to evaluate the molecular mechanisms involved in the behaviour of MLT in EAE, and to quantify other cytokines in different biological media in order for MLT to be considered an anti-inflammatory agent capable of regulating MS. (AU)

A comparative study of melatonin and immunomodulatory therapy with interferon beta and glatiramer acetate in a mouse model of multiple sclerosis. / Estudio comparativo de melatonina contra los tratamientos inmunomoduladores (interferón beta y acetato de glatirámero) en un modelo murino de esclerosis múltiple.

INTRODUCTION: Multiple sclerosis (MS) is a chronic, demyelinating, autoimmune disease of the central nervous system causing neuroinflammation. Experimental autoimmune encephalitis (EAE) is a model of the disease. MS is classically treated with interferon beta (IFN-ß) and glatiramer acetate (GA). Melatonin (MLT) has been reported to modulate immune system responses. The aim of the present study is to analyse the effects of MLT administration in comparison with the first-line treatments for MS (IFN-ß and GA). METHODS: EAE was induced in male Sprague-Dawley rats; the animals subsequently received either IFN-ß, GA, or MLT. Cerebrospinal fluid (CSF) samples were analysed by multiplex assay to determine the levels of proinflammatory cytokines. The neurological evaluation of EAE was also recorded. RESULTS: All immunised animals developed EAE. We evaluated the first relapse-remission cycle, observing that IFN-ß and GA had better results than MLT in the clinical evaluation. Neither EAE nor any of the treatments administered modified CSF IL-1ß and IL-12p70 concentrations. However, IFN-ß and MLT did decrease CSF TNF-α concentrations. CONCLUSIONS: Further studies are needed to evaluate the molecular mechanisms involved in the behaviour of MLT in EAE, and to quantify other cytokines in different biological media in order for MLT to be considered an anti-inflammatory agent capable of regulating MS.

Tumor necrosis factor haplotype diversity in Mestizo and native populations of Mexico.

The so-called tumor necrosis factor (TNF) block includes the TNFA, lymphotoxin alpha and beta (LTA and LTB) genes with single-nucleotide polymorphisms (SNP) and microsatellites with an allele frequency that exhibits interpopulation variability. To date, no reports have included both SNPs and microsatellites at the TNF block to study Mestizo or Amerindian populations from Mexico. In this study, samples of five Mexican Mestizo populations (Durango, Guadalajara, Monterrey, Puebla, and Tierra Blanca) and four native-Mexican populations (North Lacandonians, South Lacandonians, Tepehuanos, and Yaquis) were genotyped for two SNPs (LTA+252A>G and TNFA-308G>A) and four microsatellites (TNFa, d, e, and f), to analyze the genetic substructure of the Mexican population. Allele and haplotype frequencies, linkage disequilibrium (LD), and interpopulation genetic relationships were calculated. There was significant LD along almost all of the TNF block but the lowest D' values were observed for the TNFf-TNFd pair. Mestizos showed higher allele and haplotype diversity than did natives. The genetic differentiation level was reduced among Mestizos; however, a slightly, but significant genetic substructure was observed between northern and southern Mexican Mestizos. Among the Amerindian populations, the genetic differentiation level was significantly elevated, particularly in both North and South Lacandonians. Furthermore, among Southern Lacandonians, inhabitants of Lacanja town were the most differentiated from all the Mexicans analyzed. The data presented here will serve as a reference for further population and epidemiological studies including these TNF polymorphisms in the Mexican population.

Protective effects of melatonin against caustic esophageal burn injury in rats.

Caustic ingestion is one of the most life-threatening events in the pediatric age group, which requires the immediate management and subsequent treatment of its most significant complication, i.e. alterations in esophageal structure. We investigated whether melatonin could reduce the esophageal burn damage induced by sodium hydroxide. It was assumed that melatonin could be effective because of its function as a direct free radical scavenger, its antioxidative actions and its ability to diminish tissue hydroxyproline (HP) levels. Esophageal burns were induced in male rats by the administration of 10% sodium hydroxide. Lipid peroxidation (LPO) products were then measured at the following times: 0, 1, 6, 24, 48 and 72 hr after treatment. Tissue HP concentrations in the injured area were assessed at 14 days after the administration of sodium hydroxide. The groups received either systemic melatonin or normal saline. There were two, non-ischemic, sham control groups treated with or without melatonin. LPO products, malondialdehyde (MDA) and 4-hydroxyalkenal (4-HDA), increased immediately after the administration of sodium hydroxide; this indicates the participation of free radicals in the development of damage. Melatonin diminished the oxidative response and the amount of HP in the late phase of the lesion. Melatonin reduced oxidative damage in the early phase of the esophageal burns induced by sodium hydroxide.