Efectos de la aplicación intrahipocampal del péptido BLMP-101 sobre una tarea de memoria espacial en ratas Wistar / Effects of intrahypocampal administration of the BLMP-101 peptide on a spatial memory task in Wistar rats

El péptido BLMP-101 posee potencial para el tratamiento de deficiencias de la memoria. Esta investigación tuvo como objetivo corroborar los resultados obtenidos en investigaciones anteriores con respecto a la evaluación del péptido BLMP-101, en cuanto a la efectividad del péptido diseñado por el grupo de Bioquímica Computacional y estructural de la Pontificia Universidad Javeriana. Sin embargo, y a diferencia de las investigaciones anteriores, el objetivo del presente estudio consistió en medir la efectividad del BLMP-101, en dosis diferentes y haciendo la aplicación intrahipocampal del péptido, para corroborar sus efectos en la facilitación de la memoria espacial. Se utilizaron 31 ratas Wistar divididas en cuatro grupos, tres experimentales y uno de comparación. El grupo de comparación, fue inyectado con solución salina y a uno de los grupos experimentales se le administró NMDA y, a los otros dos, dosis diferentes del péptido BLMP-101 (0.3, 3.0 ug/ul). Los resultados sugieren que el péptido BLMP-101 con dosis de 3.0 ug/ul, facilitan la memoria espacial, mejor que el NMDA.

The BLMP-101 peptide has the potential features to treat memory deficiency. The herein research aimed at corroborating the results obtained in previous researches and tests conducted on the effectiveness of the peptide BLMP-101 designed by the Computational and Structural Biochemestry Unit of the Pontificia Universidad Javeriana, Colombia. However, and unlike previous researches, the objective of this paper measured the effectiveness of the BLMP-101peptide, when supplied in different dozes and through intrahipocampal application to confirm its effects to facilitate spatial memory. 31 Wistar rats were used into 4 different groups: three treatment groups and one control group. The control group was infused with saline solution, and one of the treatment groups was infused with NMDA, while the other two experimental groups were infused with different dozes of the BLMP-101peptide (0.3, 3.0 ug/ul). Results suggest that the BLMP-101 peptide, when supplied in 3.0 ug/ul, facilitates spatial memory showing better results than the NMDA.

Estudio computacional de las relaciones evolutivas de los receptores ionotrópicos NMDA, AMPA y kainato en cuatro especies de primates / Computational study of the evolutionary relationships of the ionotropic receptors NMDA, AMPA and kainate in four species of primates / Estudo computacional das relações evolutivas dos receptores ionotrópicos NMDA, AMPA e cainato em quatro espécies de primatas

Objetivo. Identificar la influencia de los cambios respecto a la estructura secundaria y a la relación evolutiva de los receptores NMDA, AMPA Y KAINATO en las especies Homo sapiens, Pan troglodytes, Pongo pygmaeus, y Macaca mulata. Materiales y métodos. Se recopilaron 91 secuencias correspondientes a los receptores NMDA, AMPA y Kainato y se sometieron a los programas de predicción de estructura secundaria, sitios de fosforilación, alineamientos múltiples, selección del modelo de evolución y predicción filogenética. Resultados. Se encontró que las subunidades GLUR5, NR2A, NR2C y NR3A presentaron cambios de estructura en la región C-terminal y aparición o pérdida de sitios de fosforilación en esta zona. Adicionalmente la predicción filogenética nos propone que las subunidades NR2 de NMDA son las más cercanas al nodo ancestral que da origen a los demás subunidades. Conclusiones. Los cambios de estructura y sitios de fosforilación en las subunidades GLUR5, NR2A, NR2C y NR3A nos sugieren variaciones en la interacción de la región C-terminal con proteínas quinasas y con proteínas con dominios PDZ lo cual podría afectar el tráfico y anclaje de las subunidades. Por otra parte la predicción filogenética nos propone que los cambios que se presentaron en las subunidades NR2 dieron origen a las demás subunidades de los receptores ionotrópicos de glutamato, básicamente porque son las subunidades de NMDA y en particular NR2D las que se encuentran más estrechamente relacionadas con el nodo ancestral que posiblemente dio origen a los iGluRs.

Objective. To identify the influence of changes on the secondary structure and evolutionary relationship of NMDA, AMPA and kainate receptors in Homo sapiens, Pan troglodytes, Pongo pygmaeus and Macaca mulatta. Materials and methods. We identified 91 sequences for NMDA, AMPA and kainate receptors and analyzed with software for predicting secondary structure, phosphorylation sites, multiple alignments, selection of protein evolution models and phylogenetic prediction. Results. We found that subunits GLUR5, NR2A, NR2C and NR3A showed structural changes in the C-terminal region and formation or loss of phosphorylation sites in this zone. Additionally the phylogenetic prediction suggests that the NMDA NR2 subunits are the closest to the ancestral node that gives rise to the other subunits. Conclusions. Changes in structure and phosphorylation sites in GLUR5, NR2A, NR2C and NR3A subunits suggest variations in the interaction of the C-terminal region with kinase proteins and with proteins with PDZ domains, which could affect the trafficking and anchoring of the subunits. On the other hand, the phylogenetic prediction suggests that the changes that occurred in the NR2 subunits gave rise to the other subunits of glutamate ionotropic receptors, primarily because the NMDA and particularly the NR2D subunits are the most closely related to the ancestral node that possibly gave rise to the iGluRs.

Objetivo. Identificar a influência das mudanças da estrutura secundária e da relação evolutiva dos receptores NMDA, AMPA e cainato nas espécies Homo sapiens, Pan troglodytes, Pongo pygmaeus e Macaca mulatta. Materiais e métodos. Foram recopiladas 91 seqüências correspondentes aos receptores NMDA, AMPA e cainato e foram submetidos a programas de predição de estrutura secundária, sítios de fosforilação, alinhamentos múltiplos, seleção do modelo de evolução e predição da filogenia. Resultados. Descobrimos que as subunidades GLUR5, NR2A, NR2C e NR3A apresentaram alterações estruturais na região C-terminal e aparecimento ou perda de sítios de fosforilação nesta área. Além disso, a predição filogenética sugere ainda que as subunidades NR2 de NMDA são as mais próximas ao nó ancestral que dá origem às demais subunidades. Conclusões. As mudanças na estrutura e nos sítios de fosforilação nas subunidades GLUR5, NR2A, NR2C e NR3A sugerem variações na interação da região C-terminal com proteínas quinase e com proteínas de domínios PDZ que poderia afetar o tráfego e fixação das subunidades. Além disso, a predição filogenética sugere que as mudanças ocorridas nas subunidades NR2 deram origem às outras subunidades de receptores ionotrópicos de glutamato, principalmente porque são subunidade NMDA e particularmente NR2D aquelas que são mais estreitamente relacionadas com o nó ancestral que provavelmente deu origem aos iGluRs.

Detección de polimorfismos en el gen GRIN1 del receptor ionotrópico de glutamato activado por NMDA en una población de Bogotá / Polymorphism detection in gene GRIN 1 of ionotropic glutamate receptor activated by NMDA of a population from Bogotá

El receptor ionotrópico de glutamato activado por N-metil-D-aspartato (iGluR-NMDA) está conformado por tres tipos diferentes de subunidades NR1, NR2A a D y NR3A y B codificadas por los genes GRIN1, GRIN2 y GRIN3. Dado que la variabilidad genómica de los GRIN está estrechamente asociada con la historia genética de la población analizada, era necesario realizar un estudio detallado del gen GRIN1 en la población colombiana. Por ello, en este trabajo se identificaron polimorfismos presentes en la región 5’-UTR y en el exón 6 del gen GRIN1, en 101 muestras de sangre de cordón umbilical de recién nacidos sanos del Hospital Universitario San Ignacio de Bogotá, y se encontró que el polimorfismo A1970G con una frecuencia del alelo menor de 28,21%, no difiere de las poblaciones de caucásicos y nativos americanos. El polimorfismo G1140A, con una frecuencia del alelo menor de 1,49%, no mostró diferencias estadísticamente significativas con la población de Taiwán. El polimorfismo A1160G sólo mostró una forma alélica...

The ionotropic glutamate receptor activated by Nmethyl-D-aspartate is composed by three different kinds of subunits NR1, NR2A to D and NR3A and B, which are codified by GRIN1, GRIN2 and GRIN3 genes. Since the GRIN genomic variability is closely related to the genetic history of the studied population, it was necessary to develop a detailed study of the frequency of the polymorphisms of the gene GRIN-1 in Colombian population. The main goal of this research was to identify polymorphisms present in 5’-UTR region and exon 6 of gene GRIN1, among 101 samples of umbilical cord taken on filter paper of healthy newborns at the University Hospital San Ignacio in Bogota. It was found that polymorphism A1970G with minor allele frequencies of 28.21%, doesn't differ significantly from the frequencies in Caucasian and native American populations. Polymorphism G1140A with minor allele frequencies of 1.49% did not show any significant statistic difference with the Taiwan population. Polymorphism A1160G just showed one allelic form, the A allele...

Immunolocalization and biochemical characterization of N-methyl-D-aspartate receptor subunit NR1 from rat brain.

The N-methyl-D-aspartate (NMDA) receptor subunit NR1 gene can produce eight isoforms in rat brain. A novel methodology for purifying NMDA receptor NR1 subunit from rat brain is reported here using chicken polyclonal antibodies (IgYs) against synthetic peptides corresponding to N1, C1 and C2' cassettes. The isolated protein was recognized by produced IgYs and commercial anti-NR1 IgGs, shown by MALDI-TOF MS a MW = 131,192 Da (glycosylated form); the enzymatically deglycosylated protein revealed a MW = 102,754 Da. The NMDA receptor NR1 subunit was characterized as being a heavily N-glycosylated protein. The isoelectric point was determined (6.3) as being different from that predicted for any of the isoforms (7.9-9.02). Attempts to separate the isoforms from the purified NR1 were unsuccessful, indicating the presence of just one isoform (NR1(111)). Immunohistochemistry on hippocampus regions CA1, CA3 and Dentate gyrus with anti-N1, anti-N2 and anti-C2' IgYs showed different staining intensity, depending upon the antibody assayed.