Synthesis and anti-HIV-1 activities of new pyrimido[5,4-b]indoles

A set of new pyrimido[5,4-b]indole derivatives that are structurally related to some non-nucleside HIV-1 reverse transcriptase inhibitors were synthesized and biologically evaluated for their activity as inhibitors of wild and mutant HIV-1 RT types in an 'in vitro' recombinant HIV-1 RT screening assay, as well as anti-infectives in HLT4lacZ-1IIIB cells. Preliminary structure-activity relationships suggest that activity is promoted by simultaneous substitution in positions 2 and 4, especially when chains of alkyldiamine type are present, and by electron-releasing substituents (methoxy) in positions 7 and 8. The inactivity or the very low activity of title derivatives does not suggest interest in AIDS therapy

Microglia Actively Remodel Adult Hippocampal Neurogenesis through the Phagocytosis Secretome

During adult hippocampal neurogenesis, most newborn cells undergo apoptosis and are rapidly phagocytosed by resident microglia to prevent the spillover of intracellular contents. Here, we propose that phagocytosis is not merely passive corpse removal but has an active role in maintaining neurogenesis. First, we found that neurogenesis was disrupted in male and female mice chronically deficient for two phagocytosis pathways: the purinergic receptor P2Y12, and the tyrosine kinases of the TAM family Mer tyrosine kinase (MerTK)/Axl. In contrast, neurogenesis was transiently increased in mice in which MerTK expression was conditionally downregulated. Next, we per-formed a transcriptomic analysis of the changes induced by phagocytosis in microglia in vitro and identified genes involved in metabolism, chromatin remodeling, and neurogenesis-related functions. Finally, we discovered that the secretome of phagocytic microglia limits the production of new neurons both in vivo and in vitro. Our data suggest that microglia act as a sensor of local cell death, modulating the balance between proliferation and survival in the neurogenic niche through the phagocytosis secretome, thereby supporting the long-term maintenance of adult hippocampal neurogenesis.This work was supported by grants from the Spanish Ministry of Economy and Competitiveness (http://www. mineco.gob.es) with FEDER funds to A.S. (BFU2012-32089 and RYC-2013-12817) to A.S. and J.V. (BFU2015-66689); a Leonardo Award from the BBVA Foundation to A.S. (IN16,_BBM_BAS_0260); a Basque Government Department of Education project to A.S. (PI_2016_1_0011; http://www.euskadi.eus/basque-government/department-educa- tion/); Ikerbasque start-up funds to J.V.; a Hungarian Research and Development Fund Grant (K116654) to B.S.; a Hungarian Brain Research Program Grant (2017-1.2.1-NKP-2017-00002) to B.S.; a National Institutes of Health Grant (AG060748) to G.L

A Model of Ischemia-Induced Neuroblast Activation in the Adult Subventricular Zone

We have developed a rat brain organotypic culture model, in which tissue slices contain cortex-subventricular zone-striatum regions, to model neuroblast activity in response to in vitro ischemia. Neuroblast activation has been described in terms of two main parameters, proliferation and migration from the subventricular zone into the injured cortex. We observed distinct phases of neuroblast activation as is known to occur after in vivo ischemia. Thus, immediately after oxygen/glucose deprivation (6–24 hours), neuroblasts reduce their proliferative and migratory activity, whereas, at longer time points after the insult (2 to 5 days), they start to proliferate and migrate into the damaged cortex. Antagonism of ionotropic receptors for extracellular ATP during and after the insult unmasks an early activation of neuroblasts in the subventricular zone, which responded with a rapid and intense migration of neuroblasts into the damaged cortex (within 24 hours). The process is further enhanced by elevating the production of the chemoattractant SDf-1α and may also be boosted by blocking the activation of microglia. This organotypic model which we have developed is an excellent in vitro system to study neurogenesis after ischemia and other neurodegenerative diseases. Its application has revealed a SOS response to oxygen/glucose deprivation, which is inhibited by unfavorable conditions due to the ischemic environment. Finally, experimental quantifications have allowed us to elaborate a mathematical model to describe neuroblast activation and to develop a computer simulation which should have promising applications for the screening of drug candidates for novel therapies of ischemia-related pathologies

Çédille, revista de estudios franceses

Presentació

Sugar recognition by human galactokinase

BACKGROUND: Galactokinase catalyses the first committed step of galactose catabolism in which the sugar is phosphorylated at the expense of MgATP. Recent structural studies suggest that the enzyme makes several contacts with galactose – five side chain and two main chain hydrogen bonds. Furthermore, it has been suggested that inhibition of galactokinase may help sufferers of the genetic disease classical galactosemia which is caused by defects in another enzyme of the pathway galactose-1-phosphate uridyl transferase. Galactokinases from different sources have a range of substrate specificities and a diversity of kinetic mechanisms. Therefore only studies on the human enzyme are likely to be of value in the design of therapeutically useful inhibitors. RESULTS: Using recombinant human galactokinase expressed in and purified from E. coli we have investigated the sugar specificity of the enzyme and the kinetic consequences of mutating residues in the sugar-binding site in order to improve our understanding of substrate recognition by this enzyme. D-galactose and 2-deoxy-D-galactose are substrates for the enzyme, but N-acetyl-D-galactosamine, L-arabinose, D-fucose and D-glucose are all not phosphorylated. Mutation of glutamate-43 (which forms a hydrogen bond to the hydroxyl group attached to carbon 6 of galactose) to alanine results in only minor changes in the kinetic parameters of the enzyme. Mutation of this residue to glycine causes a ten-fold drop in the turnover number. In contrast, mutation of histidine 44 to either alanine or isoleucine results in insoluble protein following expression in E. coli. Alteration of the residue that makes hydrogen bonds to the hydroxyl attached to carbons 3 and 4 (aspartate 46) results in an enzyme that although soluble is essentially inactive. CONCLUSIONS: The enzyme is tolerant to small changes at position 2 of the sugar ring, but not at positions 4 and 6. The results from site directed mutagenesis could not have been predicted from the crystal structure alone and needed to be determined experimentally

Synthesis and evaluation of new Reissert analogs as HIV-1 reverse transcriptase inhibitors. 1. Quinoline and quinoxaline derivatives

The synthesis and preliminary evaluation of new quinoline and quinoxaline derivatives (obtained by applying the original Reissert method, conveniently modified) as HIV-1 Reverse Transcriptase (RT) inhibitors are presented in this paper; likewise, the first structure-activity relationships are also proposed. Propyl 2-cyano-1(2H)-quinolin-carboxylate 2e, isopropyl 2-cyano-1 (2H)-quinolincarboxylate 2f, butyl 2-cyano-1 (2H)-quinolincarboxylate 2g and isobutyl 2-cyano-1 (2H)-quinolincarboxylate 2h have been selected as lead compounds. These compounds are active against the HIV-1 RT mutant type P236L (2f, IC50 = 1.2 microM) and present activity as anti-infective agents in HLT41acZ-1IIIB cells, showing no cytotoxicity at the active concentrations

Presentation

El pasado mes de abril iniciamos una nueva etapa en Çédille, representada principalmente por su traslado a la plataforma Open Journal System (OJS) de la Universidad de La Laguna, así como por la renovación y reasignación de competencias del Consejo de Redacción. Durante este tiempo, hemos tenido que adaptarnos, experimentar y comprender, pacientemente, el funcionamiento de esta nueva herramienta que es OJS. Ello ha supuesto, en algunos casos, que se hayan producido determinadas dificultades de comunicación con nuestros lectores y evaluadores, o que se hayan ocasionado pequeños retrasos en la gestión de la revista. Como nuestros seguidores saben, muy recientemente hemos sufrido, además, un ataque informático que no solo impidió el acceso a la plataforma durante varios días (justo en el momento final de producción de este número), sino que obligó a trasladar nuestro sitio web a otro servidor y a implementar nuevas medidas de seguridad. Afortunadamente, gracias al buen hacer y profesionalidad de Juan Ascanio Amigó, asesor técnico de OJS para la Universidad de La Laguna, hemos logrado salir airosos de los problemas, complicaciones y secuelas que nos hemos ido encontrando en este tiempo. En este número que ahora ve la luz contamos con treinta y cuatro contri-buciones que superan, en total, las setecientas páginas. Así, Amelia Gamoneda Lanza y Francisco González Fernández se han encargado de coordinar una nueva entrega –la undécima– de la serie «Monografías», donde han reunido una ..