3,438 research outputs found

    The landscape of the methodology in drug repurposing using human genomic data:a systematic review

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    The process of drug development is expensive and time-consuming. In contrast, drug repurposing can be introduced to clinical practice more quickly and at a reduced cost. Over the last decade, there has been a significant expansion of large biobanks that link genomic data to electronic health record (EHR) data, public availability of various databases containing biological and clinical information, and rapid development of novel methodologies and algorithms in integrating different sources of data. This review aims to provide a thorough summary of different strategies that utilize genomic data to seek drug-repositioning opportunities. We searched MEDLINE and EMBASE databases to identify eligible studies up until 1st May 2023, with a total of 102 studies finally included after two-step parallel screening. We summarized commonly used strategies for drug repurposing, including Mendelian randomization, multi-omic-based and network-based studies, and illustrated each strategy with examples, as well as the data sources implemented. By leveraging existing knowledge and infrastructure to expedite the drug discovery process and reduce costs, drug repurposing potentially identifies new therapeutic uses for approved drugs in a more efficient and targeted manner. However, technical challenges when integrating different types of data and biased or incomplete understanding of drug interactions are important hindrances that cannot be disregarded in the pursuit of identifying novel therapeutic applications. This review offers an overview of drug repurposing methodologies, providing valuable insights and guiding future directions for advancing drug repurposing studies

    Characterization of exosomal microRNAs in preterm infants fed with breast milk and infant formula

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    Breastfeeding not only reduces infection-related morbidity, but also increases growth of preterm infants. Advantages of breast milk (BM) for preterm infants are significant. They continue to be studied. However, because not all preterm infants can receive breastfeeding, bovine-based infant formula (IF) is used as an alternative, which may increase the risk of several preterm complications. Exosomes isolated from biofluids are emerging as biomarkers in research of various diseases. Here, we characterized miRNA contents of exosomes in urine and serum samples of preterm infants who were BM and IF fed and performed transcriptomic analysis of small RNA libraries. We identified significantly up-regulated 6 miRNAs and 10 miRNAs, respectively. Gene Ontology (GO) analysis revealed that target genes of these miRNAs might participate in neuronal development, immunity modulation, detoxification of reactive oxygen species, and transmembrane exchange. Our data suggest that exosome-based systemic screening for preterm infants with breastfeeding might be a screening tool for identifying target molecules involved in therapy for preterm infants in neonatal intensive care unit (NICU) and for future application as nutraceutical formulations or pharmaceuticals

    Combining gene-editing with brain imaging: from genes to molecules to networks

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    "Receptors, transporters and ion channels are important targets for therapy development in neurological diseases, [...] but their mechanistic role in pathogenesis is often poorly understood. Gene-editing and in vivo imaging approaches will help to identify the molecular and functional role of these targets and the consequence of their regional dysfunction on whole-brain level. Here, we combine CRISPR/Cas9 gene-editing with in vivo PET and fMRI to investigate the direct link between genes, molecules, and the brain connectome. The extensive knowledge of the Slc18a2 gene encoding the VMAT2, involved in the storage and release of DA, makes it an excellent target for studying the gene networks relationships while structurally preserving neuronal integrity and function. We edited the Slc18a2 in the SNc of adult rats and used in vivo molecular imaging besides behavioral, histological, and biochemical assessments to characterize the CRISPR/Cas9-mediated VMAT2 KD. Simultaneous PET/fMRI was performed to inspect the molecular and functional brain adaptations, beyond the predicted dopaminergic changes. We found a regional increase in postsynaptic DA receptor availability, preceded by a reorganization of brain networks that adapt to reduced DA transmission states by becoming functionally connected and organized. We observed that FC adaptations are stage-specific and follow the selective impairment of presynaptic DA storage and release. Further, the observed hyperconnectivity within and between brain networks spreads from the contralateral thalamus and prefrontal cortical regions to the striata and hippocampi. Our study reveals that recruiting different brain networks is an early response to the dopaminergic dysfunction preceding neuronal cell loss. Our combinatorial approach is a novel tool to investigate the impact of specific genes on brain molecular and functional dynamics which will help to develop tailored therapies for normalizing brain function. The method can easily be transferred to higher- order species allowing for a direct comparison of the molecular imaging findings" [1]. 86 Future studies could benefit from in vivo reporter gene PET probes to quantitatively assess and monitor the Cas9 and sgRNA brain expression over time [38, 220]. Indeed, in vivo reporter gene imaging is a powerful tool to monitor gene therapy and image exogenous gene expression in the brain of preclinical models of neurological diseases. Despite several reporter genes have been developed in the last years, these show major limitations. Indeed, most available reporter gene systems are based on endogenously expressed genes, resulting in high background binding or low brain uptake. Here, we characterized the pharmacokinetics and metabolism of [11C]TMP, a novel PET reporter probe which binds to EcDHFR-engineered cells and shows potential for imaging ectopic gene expression in xenografted tumor models in vitro and in vivo [47]. We found that [11C]TMP presents several unfavorable characteristics; dependency on PgP efflux transport at the BBB, hindering its brain uptake in the rat species, and in vivo metabolism, hampering the PET data quantification. Our study shows that [11C]TMP is not a suitable PET reporter gene probe to image exogeneous gene expression in the rat brain, presenting low brain uptake and fast metabolism. Future studies should focus on the investigation of different targets and the development of [11C]TMP analogs with more favorable pharmacokinetics and detectability, which are neither PgP substrate nor rapidely metabolized. [1].Marciano et al., PNAS, 202

    Introduction to Psychology

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    Introduction to Psychology is a modified version of Psychology 2e - OpenStax

    Targeting organogenesis and beta cell survival: role of the LRH1/NR5A2-PTGS2/COX2 signaling axis in pancreatic islet physiology and pathophysiology

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    Programa de Doctorado en BiotecnologĂ­a, IngenierĂ­a y TecnologĂ­a QuĂ­micaLĂ­nea de InvestigaciĂłn: BiotecnologĂ­a, Biomedicina y Ciencias de la SaludClave Programa: DBICĂłdigo LĂ­nea: 110Type 1 Diabetes Mellitus (T1DM) is a disease caused by the selective destruction of pancreatic islet beta cells by aberrant activation of the immune system, characterized by a subsequent chronic unresolved proinflammatory status within the pancreas. Up to date, no effective therapies have been developed to cure this autoimmune disorder, which indeed, apart from the beta cell death and subsequent lack of insulin, leads to long-term complications that substantially impact on life quality and shorten life expectancy. However, our laboratory recently reported promising outcomes from the in vivo activation of a nuclear receptor, denoted as Liver Receptor Homolog 1 (also known as (a.k.a.) Nuclear Receptor Subfamily 5 Group A Member 2, LRH1/NR5A2), using different preclinical mouse models of autoimmune diabetes, and also in vitro, by mimicking the stress/proinflammatory conditions that characterize T1DM in both, mouse and human primary islet-cell cultures. These beneficial effects derived from the treatment with a chemical agonist of LRH1/NR5A2, codename BL001, which potentially favoured a crosstalk between the immune system and islet cells, aimed at protecting the beta cell mass via increasing its survival. Understanding the molecular signaling and consequences derived from LRH1/NR5A2 expression and activation in beta cells was the following step to exploit its therapeutic value within T1DM conditions. In this Thesis, we first uncovered the essential role of LRH1/NR5A2 expression in beta cells during neonatal development. We found that the LRH1/NR5A2 constitutive ablation in the beta cell mass caused a significant reduction of this cell type, mainly characterized by blunted proliferation, along with detrimental consequences in the metabolic and physical health of mouse pups that culminated in early death. We next demonstrated that the LRH1/NR5A2 specific activation in beta cells was the responsible of the beneficial effects observed in vivo, after BL001 treatment. Using an inducible approach, LRH1/NR5A2 ablation in adult beta cells abolished the protective effect of BL001 in streptozotocin (STZ)-treated mice, correlating with an almost complete beta cell mass destruction. In order to get insight into the mode of action of this potential anti-diabetic drug in beta cells, we next explored the molecular branches of the BL001-LRH1/NR5A2 axis, focusing on the inducible Prostaglandin Endoperoxidase Synthase-2 gene (a.k.a. Cyclooxygenase-2, Ptgs2/Cox2), previously shown to be upregulated by BL001, and which plays a role in immunomodulation. Ptgs2/Cox2 downstream signaling involves the secretion of Prostaglandin E2 (PGE2) and activation of one or several Prostaglandin G-protein coupled receptors (a.k.a. E-Prostanoid receptors, PTGERs/EPs). We found that mouse islets treated in vitro with BL001 upon a proinflammatory cytokine (CTK) challenge produced PGE2 massively. Importantly, both silencing of Ptgs2/Cox2 gene or downstream blockade of the anti-apoptotic PTGER1/EP1 receptor negated BL001-mediated increased islet-cell survival upon the CTK treatment, establishing the molecular survival signaling axis in mouse beta cells as follows: BL001-LRH1/NR5A2-Ptgs2/Cox2-PGE2-PTGER1/EP1. In parallel, we uncovered the deleterious role of the pro-apoptotic PTGER3/EP3 in an in vivo context, using the RIP-B7.1 mouse model of autoimmune diabetes. We found that PTGER3/EP3 antagonism reduced insulitis and protected the beta cell mass in these animals. Finally, as a future therapy for T1DM, it was mandatory to translate our survival cascade to a human setting. As such, we successfully recapitulated part of this pathway in human induced-Pluripotent Stem Cells (hiPSCs) derived islet-like organoids. This research work provides a complete molecular characterization of LRH1/NR5A2 activation specifically in the beta cell mass, which could be further fine-tuned to finally develop a successful therapy for T1DM.Universidad Pablo de Olavide de Sevilla. Departamento de BiologĂ­a Molecular e IngenierĂ­a BioquĂ­mic

    The structural and mechanical characterization of biological systems and interfaces for the study of protein misfolding diseases

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    My PhD project involved the use of high-resolution microscopy techniques to study the mechanisms driving neurodegeneration in protein aggregation diseases, and to investigate the effects of anti-aggregation drugs. Several pieces of evidence indicate that in neurodegenerative diseases, such as Alzheimer’s and Parkinson’s diseases, toxic behaviour could result from the action of amyloid aggregates. The latter are highly organized and insoluble aggregates that are formed upon misfolding and aggregation of soluble proteins which undergo destabilization of their native structure. These proteins share the common characteristic of aggregating into fibrillar structures, referred to as "amyloid fibrils" with a high content of β-sheets and specific cross-beta arrangement. The study was conducted using advanced atomic force microscopy (AFM) both as a single technique to mechanistically and structurally characterize biological systems and interfaces involved in the interaction with toxic protein aggregates (through imaging and analysis of force/distance curves), and as a combined technique, together with optical microscopy, to understand the molecular mechanisms of protein aggregation, which represents a crucial problem to counteract misfolded protein diseases

    Studying the interplay between ageing and Parkinson's disease using the zebrafish model

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    Parkinson’s disease (PD) is a neurodegenerative disorder characterised by the loss of dopaminergic neurons in the substantia nigra. Ageing is the major risk factor for developing PD but the interplay between ageing and PD remains elusive. To investigate the effect of ageing on PD-relevant pathological mechanisms, zebrafish mutant lines harbouring mutations in ageing-associated genes (klotho-/-, sirt1-/-, satb1a-/-, satb1b-/- and satb1a-/-;satb1b-/-) were generated, using CRISPR/Cas9 gene editing. Likewise, a chemical model for SIRT1 deficiency was utilised. klotho-/- zebrafish displayed an accelerated ageing phenotype at 3mpf and reduced survival to 6mpf. Dopaminergic neuron number, MPP+ susceptibility and microglial number were unaffected in klotho-/- larvae. NAD+ levels were decreased in 6mpf klotho-/- brains. However, ATP levels and DNA damage were unaffected. sirt1-/- zebrafish did not display a phenotype through adulthood. il-1β and il-6 were not upregulated in sirt1-/- larvae, and chemical inhibition of sirt1 did not increase microglial number. cdkn1a, il-1β and il-6 were not upregulated in satb1a-/- and satb1b-/- larvae. Dopaminergic neuron number and MPP+ susceptibility were unaffected in satb1a-/- larvae. However, satb1b-/- larvae demonstrated a moderate decrease in dopaminergic neuron number but equal susceptibility to MPP+ as satb1b+/+ larvae. Adult satb1a-/- but not adult satb1b-/- zebrafish were emaciated. satb1a-/-;satb1b-/- zebrafish did not display a phenotype through adulthood. Transgenic zebrafish expressing human wildtype α-Synuclein (Tg(eno2:hsa.SNCA-ires-EGFP)) were crossed with klotho-/- and sirt1-/- zebrafish, and treated with a sirt1-specific inhibitor. Neither genetic cross affected survival. The klotho mutation did not increase microglial number in Tg(eno2:hsa.SNCA-ires-EGFP) larvae. Likewise, sirt1 inhibition did not induce motor impairment or cell death in Tg(eno2:hsa.SNCA-ires-EGFP) larvae. In conclusion, the suitability of zebrafish for studying ageing remains elusive, as only 1 ageing-associated mutant line displayed accelerated ageing. However, zebrafish remain an effective model for studying PD-relevant pathological mechanisms due to the availability of CRISPR/Cas9 gene editing, neuropathological and neurobehavioral tools
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