Hernan Mauricio Rivera Escobar

To explore the regulatory aspects of mRNAs and miRNAs in suicide, we integrated transcriptomic data from GEO datasets. The analysis of mRNA expression in the prefrontal cortex of suicide victims with major depressive disorder revealed a differential profile with 27 downregulated mRNAs, including HSPA1A, HSPA1B, DNAJB1, NR4A1, and GADD45B, which are involved in proteostasis, transcriptional regulation, and apoptosis. Functional enrichment analysis using KEGG and Gene Ontology (GO) revealed significant associations with synaptic plasticity, neuronal survival, and signaling pathways, including MAPK, TGF-β, Wnt, p53, and neurotrophins. Subsequently, using the GSE34120 GEO dataset of miRNAs from the frontal cortex of suicide victims, 105 dysregulated miRNAs were identified. The networks revealed compact regulatory modules with hsa-miR-576-3p, hsa-miR-493, and hsa-miR-550, as well as highly connected central nodes such as hsa-miR-30b, hsa-miR-16a-5p, hsa-miR-181a-5p, and hsa-miR-184. The integration of both profiles allowed the elaboration of miRNA–mRNA regulatory networks in which TP53, FOXO3, RELA, and FOS interact with multiple dysregulated miRNAs. These findings support the notion that suicide involves complex post-transcriptional dysregulation, particularly related to astrocytic function and neurotrophic signaling, with potential diagnostic and therapeutic applications.

Reactive oxygen species (ROS) are intermediates in oxidation–reduction reactions with the capacity to modify biomolecules and temporarily or permanently alter cell behaviour through signalling pathways under physiological and pathophysiological conditions where there is an imbalance between oxidative factors and the antioxidant response of the organism, a phenomenon known as oxidative stress. Evidence suggests that the differential modulation of ROS-mediated oxidative stress occurs in the pathogenesis and progression of melanoma, and that this imbalance in redox homeostasis appears to be functionally linked to microRNA (miRNA o miRs)-mediated non-mutational epigenetic reprogramming involving genes and transcription factors. The relationship between ROS-mediated stress control, tumour microenvironment, and miRNA expression in melanoma is not fully understood. The aim of this review is to analyse the involvement of miRNAs in the modulation of the signalling pathways involved in ROS-mediated oxidative stress in melanoma. It is hoped that these considerations will contribute to the understanding of the mechanisms associated with a potential epigenetic network regulation, where the modulation of oxidative stress is consolidated as a common factor in melanoma, and therefore, a potential footprint poorly documented.

Reactive oxygen species (ROS) are intermediates in oxidation-reduction reactions with the capacity to modify biomolecules and temporarily or permanently alter cell behaviour through signalling pathways under physiological and pathophysiological conditions where there is an imbalance between oxidative factors and the antioxidant response of the organism, a phenomenon known as oxidative stress. Evidence suggests that differential modulation of ROS-mediated oxidative stress occurs in the pathogenesis and progression of melanoma, and that this imbalance in redox homeostasis appears to be functionally linked to microRNA-mediated non-mutational epigenetic reprogramming involving genes and transcription factors. The relationship between ROS-mediated stress control, tumour microenvironment and microRNAs expression in melanoma is not fully understood. The aim of this review is to analyze the involvement of miRNAs in the modulation of signalling pathways involved in ROS-mediated oxidative stress in melanoma. It is hoped that these considerations will contribute to the understanding of the mechanisms associated with a potential epigenetic network regulation, where the modulation of oxidative stress is consolidated as a common factor in melanoma and therefore a potential footprint poorly documented.

Contexto: En Colombia, la baja cobertura de plantas de tratamiento de aguas residuales conlleva a una compleja problemática ambiental, ya que estas aguas son usadas generalmente como sistemas de riego para cultivos y, en ocasiones, para el consumo humano en zonas rurales. Objetivo: Informar acerca del saneamiento básico de las aguas residuales, los sistemas de tratamiento, el uso de microorganismos exoelectrogénicos en biorreactores, así como, los avances reportados frente al uso de los sistemas bioelectroquímicos y su posible implementación en Colombia. Metodología: Se describe la capacidad y cobertura de los sistemas de tratamiento en las regiones del país; posteriormente, se presenta el fundamento teórico de los microorganismos que interactúan en los sistemas bioelectroquímicos; y se documenta el uso de esta tecnología para depurar contaminantes. Resultados: El uso de bacterias exoelectroquímicas puede degradar carga orgánica contenida en las aguas residuales; los sistemas bioelectroquímicos aprovechan la capacidad de los microorganismos para transferir electrones a través de un circuito eléctrico por medio de voltaje, y obtener energía en forma de corriente eléctrica o combustibles con alto poder calorífico. Conclusiones: La implementación de estos sistemas en Colombia requiere de inversión tecnológica, humana y de infraestructura en las principales plantas de tratamiento de aguas residuales, dada la complejidad y variabilidad de los fenómenos bioelectroquímicos asociados a la conversión de materia orgánica.

Background: Many microRNAs have been identified as critical mediators in the progression of melanoma through its regulation of genes involved in different cellular processes such as melanogenesis, cell cycle control, and senescence. However, microRNAs’ concurrent participation in syngeneic mouse B16F1 melanoma cells simultaneously induced decreased proliferation and differential pigmentation by exposure to 5-Brd-2′-dU (5’Bromo-2-deoxyuridine) and L-Tyr (L-Tyrosine) respectively, is poorly understood. Aim: To evaluate changes in the expression of microRNAs and identify which miRNAs in-network may contribute to the functional bases of phenotypes of differential pigmentation and reduction of proliferation in B16F1 melanoma cells exposed to 5-Brd-2′-dU and L-Tyr. Methods: Small RNAseq evaluation of the expression profiles of miRNAs in B16F1 melanoma cells exposed to 5-Brd-2′-dU (2.5 μg/mL) and L-Tyr (5 mM), as well as the expression by qRT-PCR of some molecular targets related to melanogenesis, cell cycle, and senescence. By bioinformatic analysis, we constructed network models of regulation and co-expression of microRNAs. Results: We confirmed that stimulation or repression of melanogenesis with L-Tyr or 5-Brd-2′-dU, respectively, generated changes in melanin concentration, reduction in proliferation, and changes in expression of microRNAs 470-3p, 470-5p, 30d-5p, 129-5p, 148b-3p, 27b-3p, and 211-5p, which presented patterns of coordinated and reciprocal co-expression, related to changes in melanogenesis through their putative targets Mitf, Tyr and Tyrp1, and control of cell cycle and senescence: Cyclin D1, Cdk2, Cdk4, p21, and p27. Conclusions: These findings provide insights into the molecular biology of melanoma of the way miRNAs are coordinated and reciprocal expression that may operate in a network as molecular bases for understanding changes in pigmentation and decreased proliferation induced in B16F1 melanoma cells exposed to L-Tyr and 5-Brd-2′-dU.

Thiol/disulfide exchange occurs in rotavirus structural proteins during contact with intestinal villus cell surface

Contexto: En Colombia, el contenido rumial bovino (CRB) es vertido generalmente a los cauces de agua y campos a cielo abierto y, dada su alta carga orgánica, su disposición final representa una amenaza de tipo ambiental, económica y social. A la fecha, es limitada la implementación de tecnologías que permitan reducir el impacto debido en parte a la escasa caracterización del CRB, información que es requerida para la construcción de modelos matemáticos de digestión anaerobia que expliquen la reducción de este bio-sólido; por otro lado, la restringida aplicación de sistemas de control y supervisión enfocados a la generación de subproductos con potencial aprovechamiento energético también constituye un motivo. Objetivo: Documentar los métodos utilizados en el desarrollo de un sistema de control y supervisión de temperatura y presión para un biodigestor discontinuo a escala de laboratorio con biomasa CRB. Métodos: Se realizó la implementación de un sistema de adquisición distribuida de señales y una interfaz de servidor web; se identificó un modelo dinámico correspondiente al comportamiento del sistema de digestión anaerobia para esta biomasa CRB. Resultados: Se logró caracterizar, mediante gravimetría y calorimetría, variables asociadas al sistema de digestión anaerobia con CRB. Frente al control, el controlador on-off mantuvo la presión del gas en el rango deseado y el controlador PI garantizó la temperatura deseada del proceso. Conclusión: Fue posible generar biogás a partir de biomasa CRB desde esquemas básicos de caracterización, supervisión y control del proceso. Introduction: In Colombia, bovine ruminal content (BRC) is generally poured into water courses and open fields and, given its high organic load, its final disposal represents an environmental, economic, and social threat. To date, the implementation of technologies that reduce the impact is limited. This is due, on the one hand, to the scarce characterization of the BRC, which is required for the construction of mathematical models of anaerobic digestion that explain the reduction of this bio-solid; and on the other hand, to the restricted application of control and supervision systems focused on the generation of by-products with potential use. Aim: To document the methods used in the development of control and monitoring system ot temperature and pressure, for a discontinuous bio-digester at laboratory scale with biomass BRC. Methods: The implementation of a distributed signal acquisition system and a web server interface were carried out; additionally, a dynamic model corresponding to the behavior of the anaerobic digestion system for this BRC biomass was identified. Results: Using gravimetry and calorimetry, it was possible to characterize variables associated with the anaerobic digestion system with BRC. As for the control, the on-off controller kept the gas pressure in the desired range and the PI controller guaranteed the desired temperature of the process. Conclusion: It was possible to generate biogas from biomass BRC from basic schemes of characterization, supervision, and control of the process.

Introducción. El virus Zika (ZIKV) es un flavivirus con envoltura, que se transmite a los seres humanos principalmente por el vector Aedes aegypti y se ha asociado con alto neurotropismo y efectos neuropáticos como el síndrome de Guillain-Barré en el adulto, microcefalia fetal y posnatal, así como un síndrome de infección congénita similar al producido por el virus de la rubeola (RV).Objetivo. Comparar las estructuras moleculares de las proteínas de envoltura E, del virus Zika (E-ZIKV) y E1, del virus de la rubeola (E1-RV) y plantear posibles implicaciones en el neurotropismo y en las alteraciones del sistema nervioso asociadas con ZIKV.Materiales y métodos. En el análisis de las estructuras moleculares de E-ZIKV (PDB: 5iZ7) y E1-RV (PDB: 4ADG) incluyó como uno de los principales criterios de comparación y alineación, la asignación y definición de elementos de la estructura secundaria, con más del 70% de identidad. Se utilizaron los programas, Vector NTI Advance® DSSP, POSA y herramientas de gestión de datos integradas (AlignX®).Resultados. La organización estructural de la proteína E-ZIKV (PDB: 5iZ7) y fue similar a E1-RV (PDB: 4ADG) (70%-80% de identidad) y se correspondió con la estructura definida para las glicoproteínas de fusión de membrana de clase II de los virus con envoltura. E-ZIKV y E1-RV exhibieron elementos estructurales de fusión altamente conservados en la región distal del dominio II, asociados con los receptores celulares de entrada del virus de la rubeola Myelin Oligodendrocyte Glycoprotein (MOG) y con los receptores celulares Axl de ZIKV y otros flavivirus.Conclusión. La comparación de las proteínas E-ZIKV y E1-RV es un paso necesario hacia la definición de otros determinantes moleculares del neurotropismo y la patogénesis del ZIKV, para generar estrategias de diagnóstico, prevención y tratamiento de las complicaciones neurológicas inducidas por el ZIKV.