eNOS-dependent S-nitrosylation of the NF-κB subunit p65 has neuroprotective effects.

Cell death by glutamate excitotoxicity, mediated by N-methyl-D-aspartate (NMDA) receptors, negatively impacts brain function, including but not limited to hippocampal neurons. The NF-κB transcription factor (composed mainly of p65/p50 subunits) contributes to neuronal death in excitotoxicity, while its inhibition should improve cell survival. Using the biotin switch method, subcellular fractionation, immunofluorescence, and luciferase reporter assays, we found that NMDA-stimulated NF-κB activity selectively in hippocampal neurons, while endothelial nitric oxide synthase (eNOS), an enzyme expressed in neurons, is involved in the S-nitrosylation of p65 and consequent NF-κB inhibition in cerebrocortical, i.e., resistant neurons. The S-nitro proteomes of cortical and hippocampal neurons revealed that different biological processes are regulated by S-nitrosylation in susceptible and resistant neurons, bringing to light that protein S-nitrosylation is a ubiquitous post-translational modification, able to influence a variety of biological processes including the homeostatic inhibition of the NF-κB transcriptional activity in cortical neurons exposed to NMDA receptor overstimulation.

Isolation and molecular characterization of Thraustochytrium strain isolated from Antarctic Peninsula and its biotechnological potential in the production of fatty acids

ABSTRACT Thraustochytrids are unicellular protists belonging to the Labyrinthulomycetes class, which are characterized by the presence of a high lipid content that could replace conventional fatty acids. They show a wide geographic distribution, however their diversity in the Antarctic Region is rather scarce. The analysis based on the complete sequence of 18S rRNA gene showed that strain 34-2 belongs to the species Thraustochytrium kinnei, with 99% identity. The total lipid profile shows a wide range of saturated fatty acids with abundance of palmitic acid (16:0), showing a range of 16.1-19.7%. On the other hand, long-chain polyunsaturated fatty acids, mainly docosahexaenoic acid and eicosapentaenoic acid are present in a range of 24-48% and 6.1-9.3%, respectively. All factors analyzed in cells (biomass, carbon consumption and lipid content) changed with variations of culture temperature (10 °C and 25 °C). The growth in glucose at a temperature of 10 °C presented the most favorable conditions to produce omega-3fatty acid. This research provides the identification and characterization of a Thraustochytrids strain, with a total lipid content that presents potential applications in the production of nutritional supplements and as well biofuels.

Modulating Mineralocorticoid Receptor with Non-steroidal Antagonists. New Opportunities for the Development of Potent and Selective Ligands without Off-Target Side Effects.

Steroidal mineralocorticoid receptor (MR) antagonists are used for treatment of a range of human diseases, but they present challenging issues of complex chemical synthesis, undesirable physical properties, and poor selectivity along with unwanted side effects. Therefore, there is a great interest in the discovery of non-steroidal ligands able to bind to the ligand-binding domain of the MR and recruit different co-regulators to produce tissue-specific therapeutic effects. Several academic groups and pharmaceutical companies have been developing a series of non-steroidal ligands that consist of different chemical scaffolds, yielding MR antagonists currently evaluated in clinical studies for the treatment of congestive heart failure, hypertension, or diabetic nephropathy. The main focus of this Perspective is to review the reported structure-activity relationships of the different series of compounds, as well as the structural studies that contribute to a better understanding of the receptor active site and are also helpful for optimization processes.

Histidine 140 plays a key role in the inhibitory modulation of the P2X4 nucleotide receptor by copper but not zinc.

To elucidate the role of extracellular histidines in the modulation of the rat P2X4 receptor by trace metals, we generated single, double, and triple histidine mutants for residues 140, 241, and 286, replacing them with alanines. cDNAs for the wild-type and receptor mutants were expressed in Xenopus laevis oocytes and in human embryonic kidney 293 cells and examined by the two electrode and patch clamp techniques, respectively. Whereas copper inhibited concentration-dependently the ATP-gated currents in the wild-type and in the single or double H241A and H286A receptor mutants, all receptors containing H140A were insensitive to copper in both cell systems. The characteristic bell-shaped concentration-response curve of zinc observed in the wild-type receptor became sigmoid in both oocytes and human embryonic kidney cells expressing the H140A mutant; in these mutants, the zinc potentiation was 2.5-4-fold larger than in the wild-type. Results with the H140T and H140R mutants further support the importance of a histidine residue at this position. We conclude that His-140 is critical for the action of copper, indicating that this histidine residue, but not His-241 or His-286, forms part of the inhibitory allosteric metal-binding site of the P2X4 receptor, which is distinct from the putative zinc facilitator binding site.

Polygraphic characterization of the sleep-epilepsy patterns in a hydranencephalic child with severe generalized seizures of the lennox-gastaut syndrome

This is the report of a hydranenecephalic child with severe generalized seizures of the Lennox-Gastaut Syndrome (LGS) who lacked the development of the entire cerebral hemispheres and had preserved the brain stem, cerebellum, hypothalamus and a portion of the thalamus as evidenced by radiological and/or physiological studies. Conventional polygraphic sleep studies in these patients showed presence of scalp EEG and other peripheral, somatic and vegetative signs characterizing the wakefulness, quiet sleep and active sleep stages. Absence of the vertex waves and disrupted sleep spindles were the major qualitative EEG abnormalities. In contrast, quantitative abnormalities in duration, latency and number of sleep cycles found in this patient were similar to those found in other children with Idiopathic Lennox-Gastaut Syndrome (ILGS). A substantial reduction in the number of interictal EEG spikes and a shortening of the ictal clonic EEG activities without concomitant EMG jerks were the most distinct epileptiform abnormalities in this child. In contrast, his basic polygraphic patterns of the tonic and apneic seizures were similar to those found in other children with ILGS. Data obtained from this child suggest that both the sleep stages and the generalized seizures of the ILGS basically depend more on the integrity of the brain stem than on the telecephalic structures

Resultados obtenidos de 105 pacientes sucesivos que ingresaron con isquemia grave que amenazaba con la pérdida de la extremidad / Results from 105 patients admitted successively with severe ischemia threatening with foot loosing

Se trata de un trabajo prospectivo, que analiza los resultados obtenidos en 105 pacientes sucesivos sin selección previa, ingresados con isquemia crónica crítica, con alto riesgo inmediato de pérdida del apoyo del pie. La edad promedio era de 68 años y 86 por ciento era de sexo masculino, las enfermedades asociadas predominantes eran las cardiorespiratorias, diabetes, vasculares encefálicas e insuficiencias renales. Los motivos de consulta fueron: dolor de reposo, necrosis o lesión ulcerada o ambos que no cicatrizaban. Todos los pacientes fueron valorados clínicamente y mediante técnicas no invasivas Doppler, eco-Doppler y fotopletismografía en el preoperatorio, complementándose con arteriografías y/o preprocedimiento. Se realizaron 10 amputaciones primarias (9,5 por ciento), 6 por imposibilidad de conservar el pie (60 por ciento), 2 por alto riesgo anestésico quirúrgico (20 por ciento) y 2 por inutilidad del miembro comprometido (20 por ciento). Se amputaron 6 pacientes a nivel de pierna, 2 con previa revascularización y 4 pacientes en muslo, no hubo complicaciones mayores, ni mortalidad. A 95 pacientes se los intentó revascularizar, en 5 (5 por ciento) no fue posible por irreconstructibilidad vascular, habiéndose explorado incluso directamente las arterias del pie. De los 90 pacientes restantes a 29 se les realizó revascularización suprainguinal (32 por ciento) y a 9 de éstos se les practicó revascularización a doble nivel supra e infrainguinal (31 por ciento). Tomaron origen en la aorta 8 puentes, en la arteria axilar 9 y 12 en la femoral común contralateral. A 61 pacientes se los revascularizó en el sector infrainguinal, el vaso receptor del puenteo más frecuentemente utilizado fue poplítea y en 20 casos (30 por ciento) fue necesario recurrir a una arteria del pie. En la cirugía suprainguinal la permeabilidad primaria fue de 96,5 por ciento secundaria de 100 por ciento, hubo 6,8 por ciento de complicaciones mayores y 3,4 por ciento de mortalidad. En este grupo se preservaron todas las extremidades. En la cirugía infrainguinal la permeabilidad primaria fue de 95 por ciento, las complicaciones mayores se presentaron en 8,1 por ciento, siendo la mortalidad de 1,6 por ciento. En este grupo se preservaron 88,5 por ciento de los pies útiles para la deambulación...

Valor de la arteriografía preoperatoria en la definición de los ejes arteriales permeables en la pierna y el pie / Value of preoperative arteriography in the definition of permeable arterial axis of leg and foot

Se tiene en cuenta que en la cirugía de salvataje de las extremidades la utilización de ejes de pierna o pie como receptores de puentes, no es infrecuente. Se analizaron los resultados de 59 aortografías por punción translumbar y 38 arteriografías por punción femoral, para definir los ejes arteriales permeables en la pierna y el pie. Esto permitió el estudio de 156 extremidades de pacientes con arteriopatía obstructiva crónica de los MMII. La aortografía muestra una PG de 28 por ciento, que no varió significativamente con o sin la existencia de lesiones ilíacas PG 36 y 24 por ciento respectivamente. La arteriografía por punción femoral tuvo una PG de 74 por ciento para definir los ejes de pierna y de 42 por ciento para los ejes del pie, lo cual lo muestra como estudio más confiable con este fin que la aortografía que tiene una PG de 28 por ciento y 8 por ciento respectivamente. Cuando el contraste de una arteriografía llega hasta el cuello del pie, la precisión de la misma para definir ejes permeables en la pierna fue de 90 por ciento para la arteria peronea, 70 por ciento para la tibial anterior y 53 por ciento para la tibial posterior. Las arterias tibiales mostraron oclusión proximal con permeabilidad distal en 50 a 54 por ciento de los casos, siendo la peronea la arteria que más frecuentemente estuvo permeable, en 90 por ciento de las veces, observándose continuidad con el eje poplíteo-tronco tibio peroneo en 74 por ciento. Teniendo en cuenta estos resultados parece aventurado decidir la indicación de irrevascularización de una extremidad, contando sólo con datos aportados por alguno de estos estudios, indefectiblemente se realizarían amputaciones mayores innecesarias, asimismo aun realizando un puente distal con dichos datos podríamos no elegir el mejor de los ejes como receptor