Terapia génica contra la insensibilidad congénita al dolor con anhidrosis

Actas del V Congreso de Señalización Celular, SECUAH 2020. 16-18 de marzo, 2020. Universidad de Alcalá. Alcalá de Henares, Madrid. España.La insensibilidad congénita al dolor es una condición congénita rara, siendo el tipo IV de la enfermedad, que además presenta anhidrosis, el más frecuente entre la población y para el cual actualmente no existe tratamiento y los estudios al respecto son puramente teóricos. En este trabajo teórico proponemos el estudio molecular de la enfermedad para permitir el desarrollo de terapias encaminadas a solventar el problema. Para ello, estudiamos el gen NTRK1, gen codificante del receptor tirosina quinasa TrkA, que actúa como regulador de la diferenciación de neuronas sensoriales y que en este caso, se encuentra mutado. El estudio de esta mutación y sus consecuencias se realizó mediante ensayos de secuenciación y genotipado de individuos, así como también se propuso una terapia génica con CRISPR/Cas9 en modelos in vivo y diversos ensayos in vitro mediante western-blot y citometría de flujo. Nuestros resultados muestran la posibilidad de diseñar un diagnóstico de portadores y de aplicar la terapia génica con el fin de revertir la mutación del gen y conseguir el correcto funcionamiento de las neuronas. La existencia de conocimiento teórico sobre la enfermedad y la posibilidad del diseño de terapias posibles para ella constituyen un paso previo para investigar las causas y consecuencias funcionales de la mism

Next generation of selenocyanate and diselenides with upgraded leishmanicidal activity

Nowadays, leishmaniasis is still treated with outdated drugs that present several obstacles related to their high toxicity, long duration, parenteral administration, high costs and drug resistance. Therefore, there is an urgent demand for safer and more effective novel drugs. Previous studies indicated that selenium compounds are promising derivatives for innovative therapy in leishmaniasis treatment. With this background, a new library of 20 selenocyanate and diselenide derivatives were designed based on structural features present in the leishmanicidal drug miltefosine. Compounds were initially screened against promastigotes of L. major and L. infantum and their cytotoxicity was evaluated in THP-1 cells. Compounds B8 and B9 were the most potent and less cytotoxic and were further screened for the intracellular back transformation assay. The results obtained revealed that B8 and B9 showed EC50 values of 7.7 µM and 5.7 µM, respectively, in L. major amastigotes, while they presented values of 6.0 µM and 7.4 µM, respectively, against L. infantum amastigotes. Furthermore, they exerted high selectivity (60 70) towards bone marrow-derived macrophages. Finally, these compounds exhibited higher TryR inhibitory activity than mepacrine (IC50 7.6 and 9.2 µM, respectively), and induced nitric oxide (NO) and reactive oxygen species (ROS) production in macrophages. These results suggest that the compounds B8 and B9 could not only exert a direct leishmanicidal activity against the parasite but also present an indirect action by activating the microbicidal arsenal of the macrophage. Overall, these new generation of diselenides could constitute promising leishmanicidal drug candidates for further studies

Identification of L. infantum trypanothione synthetase inhibitors with leishmanicidal activity from a (non-biased) in-house chemical library

Redox homeostasis in trypanosomatids is based on the low-molecular-weight trypanothione, an essential dithiol molecule that is synthetized by trypanothione synthetase (TryS) and maintained in its reduced state by trypa- nothione disulfide reductase (TryR). The fact that both enzymes are indispensable for parasite survival and absent in the mammalian hosts makes them ideal drug targets against leishmaniasis. Although many efforts have been directed to developing TryR inhibitors, much less attention has been focused on TryS. The screening of an in-house library of 144 diverse molecules using two parallel biochemical assays allowed us to detect 13 inhibitors of L. infantum TryS. Compounds 1 and 3 were characterized as competitive inhibitors with Ki values in the low micromolar range and plausible binding modes for them were identified by automated ligand docking against refined protein structures obtained through computational simulation of an entire catalytic cycle. The proposed binding site for both inhibitors overlaps the polyamine site in the enzyme and, additionally, 1 also occupies part of the ATP site. Compound 4 behaves as a mixed hyperbolic inhibitor with a Ki of 0.8 μM. The activity of 5 is clearly dependent on the concentration of the polyamine substrate, but its kinetic behavior is clearly not compatible with a competitive mode of inhibition. Analysis of the activity of the six best inhibitors against intracellular amastigotes identified 5 as the most potent leishmanicidal candidate, with an EC50 value of 0.6 μM and a selectivity index of 35.This work has been supported by the Spanish MICINN (Projects PID2019-104070RB-C21 and PID2019-104070RBC22), the Spanish National Research Council (CSIC, Projects CSIC-PIE-201980E100 and CSIC-PIE-201980E028), and the Comunidad de Madrid (PLATESA2-CM ref S-2018/BAA-4370). The MCIN is also acknowledged for the pre- doctoral fellowship to M.A.C.Peer reviewe

Identification of 1,2,3-triazolium salt-based inhibitors of Leishmania infantum trypanothione disulfide reductase with enhanced antileishmanial potency in cellulo and increased selectivity

N-methylation of the triazole moiety present in our recently described triazole-phenyl-thiazole dimerization disruptors of Leishmania infantum trypanothione disulfide reductase (LiTryR) led to a new class of potent in- hibitors that target different binding sites on this enzyme. Subtle structural changes among representative library members modified their mechanism of action, switching from models of classical competitive inhibition to time- dependent mixed noncompetitive inhibition. X-ray crystallography and molecular modeling results provided a rationale for this distinct behavior. The remarkable potency and selectivity improvements, particularly against intracellular amastigotes, of the LiTryR dimerization disruptors 4c and 4d reveal that they could be exploited as leishmanicidal agents. Of note, L. infantum promastigotes treated with 4c significantly reduced their low- molecular-weight thiol content, thus providing additional evidence that LiTryR is the main target of this novel compound.This work has been financially supported by the Spanish MICINN (Projects PID2019-104070RB-C21, PID2019-104070RB-C22 and PID2020-115331 GB-I00), the Spanish Agencia Estatal Consejo Superior de Investigaciones Científicas (CSIC, Projects CSIC-PIE-201980E100 and CSIC-PIE-201980E028), and the Comunidad de Madrid (PLATESA2-CM ref. S-2018/BAA-4370). The Spanish MEC is also acknowledged for FPU grants to A. R. and to J.C.G. P.A.S.M. thanks to the Division of Physio- logical Chemistry and the Otto-Loewi Research Center of the Medical University of Graz for their support with the scienfic cluster where the calculations contained in this work were run. We thank Ricardo Lau- reano-Rodríguez, Juan Antonio Rodríguez-Gutierrez, and Laura Lagar- tera for technical assistance with SPR experiments.Peer reviewe

Identificación de dianas terapéuticas contra la infección por SARS-CoV-2

La aparición del nuevo coronavirus SARS-CoV-2 a finales de 2019 ha resultado en una pandemia internacional debido a la multitud de contagios y muertes documentadas. Los coronavirus provocan enfermedades respiratorias de gravedad gradual, llegando a producir lesiones pulmonares graves e incluso fallo multiorgánico. A pesar de que diferentes tipos de coronavirus han infectado a humanos con anterioridad, es necesaria una investigación en profundidad del SARS-CoV-2 para poder abordar diferentes estrategias terapéuticas frente a la infección que produce. En este artículo, se presentan las características fundamentales del SARS-CoV-2 que favorecen la elevada infectividad y transmisibilidad del virus, así como sus diferencias principales con los coronavirus que le preceden. En este sentido, este virus utiliza el receptor ECA-2 para su entrada en las células y, en el proceso infectivo, es fundamental la participación de una glucoproteína de espiga (S) que se encuentra anclada a la envoltura de SARS-CoV-2. Gracias a varios estudios independientes, se ha podido determinar el mecanismo por el que se produce el reconocimiento entre el virus y su receptor celular, en el que interviene fundamentalmente la proteína S. Asimismo, se ha encontrado que esta proteína alberga un sitio de escisión de furina, una proteasa encargada del procesamiento proteolítico de las subunidades de la proteína S y cuyo papel es primordial para que se produzca la fusión de membranas vírica y celular. Finalmente, en base al estudio realizado, se proponen diversos inhibidores basados en el bloqueo de la interacción virus-receptor y de la fusión de membranas, que se fundamentan en la implicación del dominio de unión con el receptor (RBD) de la proteína S y en la proteasa furina como principal desencadenante del proceso de fusión a través de la escisión proteolítica