Role of astrocytes and glutamate transporter EAAT2 / GLT1 in Amyotrophic Lateral Sclerosis

Daniel Castro: Estudiante de Medicina, Ciclo de Metodología Científica II, Facultad de Medicina, Universidad de la República, Uruguay. La contribución en la realización del trabajo fue equivalente a la de los demás estudiantes.-- Elke Díaz: Estudiante de Medicina, Ciclo de Metodología Científica II, Facultad de Medicina, Universidad de la República, Uruguay. La contribución en la realización del trabajo fue equivalente a la de los demás estudiantes.-- Irma Lombardo: Estudiante de Medicina, Ciclo de Metodología Científica II, Facultad de Medicina, Universidad de la República, Uruguay. La contribución en la realización del trabajo fue equivalente a la de los demás estudiantes.-- Patricia Cassina: Docente supervisor. Departamento de Histología y Embriología de la Facultad de Medicina, Universidad de la República, Montevideo, Uruguay. Contacto: Departamento de Histología y Embriología, Facultad de Medicina, Avda. Gral. Flores 2125, 11800 Montevideo, Uruguay. Tel. (5982) 924 2703. Email: [email protected] Laura Martínez-Palma: Docente supervisor. Departamento de Histología y Embriología de la Facultad de Medicina, Universidad de la República, Montevideo, Uruguay.La Esclerosis Lateral Amiotrófica (ELA) es una enfermedad neurodegenerativa fatal, progresiva que afecta las motoneuronas superiores e inferiores del sistema nervioso central y se acompaña de reactividad glial. La patogenia de esta enfermedad no está del todo clara. Se han postulado diferentes mecanismos dentro de los cuales se destacan las alteraciones en el procesamiento del ARN, en el metabolismo proteico, en el transporte axonal y en la función mitocondrial, aumento del estrés oxidativo y excitotoxicidad. Los astrocitos presentan prolongaciones que rodean la sinapsis, donde se localizan los transportadores de glutamato que captan el exceso del neurotransmisor durante la actividad sináptica. En la ELA se han encontrado alteraciones en este mecanismo lo cual ha resaltado la participación de la glía en la progresión de la enfermedad. El glutamato actúa sobre dos familias de receptores: NMDA y no NMDA, cuyas alteraciones se vinculan con la patogenia de la enfermedad. Además, se ha probado que existe una alteración en la función y disponibilidad del transportador de glutamato EAAT2/GLT1, que contribuye al aumento de la concentración de glutamato extracelular. En este trabajo, el objetivo fue revisar la bibliografía sobre el rol de los astrocitos y el transportador de glutamato EAAT2/GLT1 en la patogenia de la ELA, con el fi n de identificar algunos interrogantes aún no dilucidados para dirigir nuevas investigaciones que puedan mejorar el tratamiento de estos pacientes.Amyotrophic Lateral Sclerosis (ALS) is a fatal, progressive neurodegenerative disease aff ecting upper and lower motor neurons of the central nervous system that is associated to glial reactivity. The pathogenesis of this disease is not entirely clear. Different mechanisms have been postulated, inclu-ding alterations in RNA processing, protein metabolism, axonal transport and mitochondrial function, increased oxidative stress and excitotoxicity. Astrocytes exhibit processes surrounding the synapse, where glutamate transporters are located to uptake the excess of neurotransmitter during synaptic activity. Alterations in this mechanism have been found in ALS and have highlighted the role of glia in the progression of ALS. Glutamate acts on two receptor families: NMDA and non-NMDA. There is evidence that links glutamate transporters dysfunction to the pathogenesis of the disease. In addition, it has been proven that alteration in the function and availability of the glutamate transporter EAAT2 / GLT1 contributes to the increase of extracellular glutamate concentration. In this work, we aim to review the literature on the role of astrocytes and the glutamate transporter EAAT2 / GLT1 in the pathogenesis of ALS, to identify unsolved questions that may guide further research to improve the treatment of these patients

Circadian rhythms of proliferation events in two mouse carcinomas

We studied the index of DNA synthesis (DNAs) of two cellular carcinomas: the hepatocellular ES12a and the mammary TN60 of mice, throughout one circadian cycle. In the results, we observed that both tumors have circadian rhythms (CRs), but the peaks of DNAs vary. Besides, the mean of DNAs along 24 h shows significative differences, the TN60 has higher values than the ES12a. These observed CR in the DNAs index in both carcinomas mean that, at least in partly, the proliferation of cancer cells can be regulated by endocrine factor as it normally occurs in ordinary cells. The big problem we can find for the chronopharmacology is that it is impossible to know in advance the rate of proliferation of each tumor.Facultad de Ciencias MédicasComisión de Investigaciones Científicas de la provincia de Buenos Aire

Aspectos biomecánicos y lesiones musculoesqueléticas en miembros superiores en tenis adaptado

Objective: To determine the phases with the greatest difficulty of execution in the technical gesture of the reverse in adapted tennis athletes. Methods: Descriptive cross-sectional study. The 8 athletes from the Vallecaucana League of adapted tennis participated. Gesture was evaluated by analyzing movement in three dimensions with the Qualisys capture system and processing the information using Visual 3D. Results: Six phases were identified in the technical backhand gesture, determining phases 4 and 6 with greater difficulty of execution. It was possible to analyze the shoulder, elbow, wrist, trunk and neck joints, identifying possible musculoskeletal injuries. Conclusion: The backhand gesture is the movement with the highest risk of injury in adapted tennis.Objetivo: Determinar las fases con mayor dificultad de ejecución en el gesto técnico del revés en deportistas de tenis adaptado. Métodos: Estudio descriptivo transversal. Participaron los 8 deportistas de la Liga Vallecaucana de tenis adaptado. Se evaluó el gesto mediante el análisis del movimiento en tres dimensiones con el sistema de captura de Qualisys y el procesamiento de la información por medio de Visual 3D. Resultados: Se identificaron seis fases en el gesto técnico del revés determinando con mayor dificultad de ejecución las fases 4 y 6. Fue posible analizar las articulaciones de hombro, codo, muñeca, tronco y cuello, identificando posibles lesiones osteomusculares. Conclusión: El gesto de revés es el movimiento de mayor riesgo de lesión en el tenis adaptado

Non surgical periodontal treatment in patients with gingivitis and moderate periodontitis. Biochemical and microbiological response

AbstractObjectiveTo ascertain inflammatory response through interleukin 1β presence and identify pathogenic microorganisms as possible immunological and microbiological markers in diagnosis and treatment non-surgical periodontal in patients with gingivitis and moderate chronic periodontitis in a sample of Mexican population.Material and methodsIn the present prospective cohort study, 18 patients with signs of gingivitis and 17 patients with moderate chronic periodontitis were selected. Samples of subgingival biofilm and of crevicular gingival fluid were collected. Interleukin 1β was quantified during the pre-treatment, post-treatment and maintenance phases of the non- surgical periodontal treatment. Continuous variables were analyzed with the Student test, as well as categorical variables which were analyzed with the Turkey-Kramer test. For independent groups the Pearson test was used.ResultsMicrobiological response variables showed that Porphyromonas gingivalis Prevotella intermedia, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans significantly decreased in subjects with gingivitis, Porphyromonas gingivalis, Tannerella forsythia, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans and Actinomyces ssp. decreased in cases. Biochemical response variables showed significant decrease in IL-1β concentration and total count in individuals with moderate chronic periodontitis in treatment maintenance phase. The same result applied to clinical response variables.ConclusionsThere is a decrease in Interleukine 1β levels with decrease in microflora. Interleukin 1β are sensitive markers for diagnosis of periodontal disease and assessment of its severity

Mitofusins modulate the increase in mitochondrial length, bioenergetics and secretory phenotype in therapy-induced senescent melanoma cells

Cellular senescence is an endpoint of chemotherapy, and targeted therapies in melanoma and the senescence-associated secretory phenotype (SASP) can affect tumor growth and microenvironment, influencing treatment outcomes. Metabolic interventions can modulate the SASP, and an enhanced mitochondrial energy metabolism supports resistance to therapy in melanoma cells. Herein, we assessed the mitochondrial function of therapy-induced senescent melanoma cells obtained after exposing the cells to temozolomide (TMZ), a methylating chemotherapeutic agent. Senescence induction in melanoma was accompanied by a substantial increase in mitochondrial basal, ATP-linked, and maximum respiration rates and in coupling efficiency, spare respiratory capacity, and respiratory control ratio. Further examinations revealed an increase in mitochondrial mass and length. Alterations in mitochondrial function and morphology were confirmed in isolated senescent cells, obtained by cell-size sorting. An increase in mitofusin 1 and 2 (MFN1 and 2) expression and levels was observed in senescent cells, pointing to alterations in mitochondrial fusion. Silencing mitofusin expression with short hairpin RNA (shRNA) prevented the increase in mitochondrial length, oxygen consumption rate and secretion of interleukin 6 (IL-6), a component of the SASP, in melanoma senescent cells. Our results represent the first in-depth study of mitochondrial function in therapy-induced senescence in melanoma. They indicate that senescence increases mitochondrial mass, length and energy metabolism; and highlight mitochondria as potential pharmacological targets to modulate senescence and the SASP.Agencia Nacional de Investigación e Innovación FCE_1_2017_1_13602

Hallux Limitus Influence on Plantar Pressure Variations during the Gait Cycle: A Case-Control Study

´[Abstract] Background: Hallux limitus is a common foot disorder whose incidence has increased in the school-age population. Hallux limitus is characterized by musculoskeletal alteration that involves the metatarsophalangeal joint causing structural disorders in different anatomical areas of the locomotor system, affecting gait patterns. The aim of this study was to analyze dynamic plantar pressures in a school-aged population both with functional hallux and without. Methods: A full sample of 100 subjects (50 male and 50 female) 7 to 12 years old was included. The subjects were identified in two groups: the case group (50 subjects characterized as having hallux limitus, 22 male and 28 female) and control group (50 subjects characterized as not having hallux limitus, 28 male and 22 female). Measurements were obtained while subjects walked barefoot in a relaxed manner along a baropodometric platform. The hallux limitus test was realized in a seated position to sort subjects out into an established study group. The variables checked in the research were the surface area supported by each lower limb, the maximum peak pressure of each lower limb, the maximum mean pressure of each lower limb, the body weight on the hallux of each foot, the body weight on the first metatarsal head of each foot, the body weight at the second metatarsal head of each foot, the body weight at the third and fourth metatarsal head of each foot, the body weight at the head of the fifth metatarsal of each foot, the body weight at the midfoot of each foot, and the body weight at the heel of each foot. Results: Non-significant results were obtained in the variable of pressure peaks between both study groups; the highest pressures were found in the hallux with a p-value of 0.127 and in the first metatarsal head with a p-value 0.354 in subjects with hallux limitus. A non-significant result with a p-value of 0.156 was obtained at the second metatarsal head in healthy subjects. However, significant results were observed for third and fourth metatarsal head pressure in healthy subjects with a p-value of 0.031 and regarding rearfoot pressure in subjects with functional hallux limitus with a p-value of 0.023. Conclusions: School-age subjects with hallux limitus during gait exhibit more average peak plantar pressure in the heel and less peak average plantar pressure in the third and fourth metatarsal head as compared to healthy children aged between 7 and 12 years old

Analysis of static plantar pressures in school-age children with and without functional Hallux Limitus: a case-control study

Background: The presence of hallux limitus in adulthood is frequently encountered in clini cal practice, generating other biomechanical, structural, and functional compensations in dynamics secondary to blockage of the main pivot in the sagittal plane, the first metatarsophalangeal joint. In addition, the presence of functional hallux limitus (FHL) in school-age children is also increasing. Currently, there is a lack of scientific literature about this condition in the pediatric population, and early diagnosis is necessary to reduce future biomechanical disorders and avoid the development of foot arthritis. The purpose of this research was to identify static plantar pressures in school-age children with and without hallux limitus. Methods: A total sample of 106 children aged between six and twelve years old was divided into two groups: the case group (53 subjects with functional hallux limitus) and the control group (53 subjects without functional hallux limitus). Data were acquired with the participants in a standing barefoot position on the pressure platform, and the hallux limitus functional test was performed in a sitting position to classify the individuals into the determined study group. The variables analyzed in the research were: plantar pressure, bilateral forefoot and rearfoot surface area, bilateral forefoot and rearfoot ground reaction forces, bilateral forefoot and rearfoot distribution of body weight, total left and right surface area, maximum pressure of the left foot and right foot, medium pressure of the left foot and right foot, ground reaction forces of the left foot and right foot, and the weight of each foot. Results: Age was the only descriptive quantitative variable that showed a significant difference between the two study groups, with a p-value of 0.031. No statistically significant differences were found between groups in the bilateral forefoot and rearfoot surface area, ground reaction forces, distribution of body weight, or maximum and medium plantar pressure in the left and right foot. Conclusions: Changes in the location of the maximum pressure were observed, particularly in older participants with FHL, but these results were not significant. The findings of this study did not show significant differences between the static plantar pressures of school-age individuals with and without functional hallux limitus

Engineering of silicon surfaces at the micro- and nanoscales for cell adhesion and migration control

The engineering of surface patterns is a powerful tool for analyzing cellular communication factors involved in the processes of adhesion, migration, and expansion, which can have a notable impact on therapeutic applications including tissue engineering. In this regard, the main objective of this research was to fabricate patterned and textured surfaces at micron- and nanoscale levels, respectively, with very different chemical and topographic characteristics to control cell–substrate interactions. For this task, one-dimensional (1-D) and two-dimensional (2-D) patterns combining silicon and nanostructured porous silicon were engineered by ion beam irradiation and subsequent electrochemical etch. The experimental results show that under the influence of chemical and morphological stimuli, human mesenchymal stem cells polarize and move directionally toward or away from the particular stimulus. Furthermore, a computational model was developed aiming at understanding cell behavior by reproducing the surface distribution and migration of human mesenchymal stem cells observed experimentally

Partial deletion 5p and partial duplication 5q due to paternal pericentric inversion

Dismorfología, Citogenética y Clínica: Resultados de estudios sobre los datos del ECEMCDuring the meiotic process, most of the structural balanced chromosome alterations will affect either the specific chromosome pairing, or the chromosome and cromatides segregation, due to the number and type of chiasmata of the chromosomes implicated in those balanced rearrangements. Thus, the major clinical significance for normal carriers is the risk of transmition to their offspring unbalanced derivative. Here we present a malformed newborn infant with an abnormal chromosome 5 consisting in a partial deletion 5p and a partial duplication 5q. This abnormal chromosome 5 was a recombinant chromosome derived from a large paternal pericentric inversion. The cytogenetic study of the family showed that there were some other members who were carriers of the same balanced inversion. The clinical features of this patient are a mixture of some anomalies clearly related to the 5p deletion or "Cri-du-Chat" syndrome, like the crying and facial appearance, together with other that are describe on patients with 5q duplication, like the cardiac malformation. Nevertheless, he also shows some congenital defects as preauricular tags and anal atresia that, as for as we know, have not been previously described in patients with a similar chromosomal alteration. A literature review was performed of the genes localize at the chromosome regions involve in the inversion, in an effort to establish a relation with the patient phenotype.N

Post-paralysis tyrosine kinase inhibition with masitinib abrogates neuroinflammation and slows disease progression in inherited amyotrophic lateral sclerosis

Background: In the SOD1G93A mutant rat model of amyotrophic lateral sclerosis (ALS), neuronal death and rapid paralysis progression are associated with the emergence of activated aberrant glial cells that proliferate in the degenerating spinal cord. Whether pharmacological downregulation of such aberrant glial cells will decrease motor neuron death and prolong survival is unknown. We hypothesized that proliferation of aberrant glial cells is dependent on kinase receptor activation, and therefore, the tyrosine kinase inhibitor masitinib (AB1010) could potentially control neuroinflammation in the rat model of ALS. Methods: The cellular effects of pharmacological inhibition of tyrosine kinases with masitinib were analyzed in cell cultures of microglia isolated from aged symptomatic SOD1G93A rats. To determine whether masitinib prevented the appearance of aberrant glial cells or modified post-paralysis survival, the drug was orally administered at 30 mg/kg/day starting after paralysis onset. Results: We found that masitinib selectively inhibited the tyrosine kinase receptor colony-stimulating factor 1R (CSF-1R) at nanomolar concentrations. In microglia cultures from symptomatic SOD1G93A spinal cords, masitinib prevented CSF-induced proliferation, cell migration, and the expression of inflammatory mediators. Oral administration of masitinib to SOD1G93A rats starting after paralysis onset decreased the number of aberrant glial cells, microgliosis, and motor neuron pathology in the degenerating spinal cord, relative to vehicle-treated rats. Masitinib treatment initiated 7 days after paralysis onset prolonged post-paralysis survival by 40 %. Conclusions: These data show that masitinib is capable of controlling microgliosis and the emergence/expansion of aberrant glial cells, thus providing a strong biological rationale for its use to control neuroinflammation in ALS. Remarkably, masitinib significantly prolonged survival when delivered after paralysis onset, an unprecedented effect in preclinical models of ALS, and therefore appears well-suited for treating ALS.Agencia Nacional de Investigación e Innovació