62 research outputs found
Novel pharmacological maps of protein lysine methyltransferases: key for target deorphanization
Epigenetic therapies are being investigated for the treatment of cancer, cognitive disorders, metabolic alterations and
autoinmune diseases. Among the diferent epigenetic target families, protein lysine methyltransferases (PKMTs), are
especially interesting because it is believed that their inhibition may be highly specifc at the functional level. Despite
its relevance, there are currently known inhibitors against only 10 out of the 50 SET-domain containing members of
the PKMT family. Accordingly, the identifcation of chemical probes for the validation of the therapeutic impact of
epigenetic modulation is key. Moreover, little is known about the mechanisms that dictate their substrate specifcity and ligand selectivity. Consequently, it is desirable to explore novel methods to characterize the pharmacological similarity of PKMTs, going beyond classical phylogenetic relationships. Such characterization would enable the
prediction of ligand of-target efects caused by lack of ligand selectivity and the repurposing of known compounds
against alternative targets. This is particularly relevant in the case of orphan targets with unreported inhibitors. Here,
we frst perform a systematic study of binding modes of cofactor and substrate bound ligands with all available SET
domain-containing PKMTs. Protein ligand interaction fngerprints were applied to identify conserved hot spots and
contact-specifc residues across subfamilies at each binding site; a relevant analysis for guiding the design of novel,
selective compounds. Then, a recently described methodology (GPCR-CoINPocket) that incorporates ligand contact
information into classical alignment-based comparisons was applied to the entire family of 50 SET-containing proteins
to devise pharmacological similarities between them. The main advantage of this approach is that it is not restricted
to proteins for which crystallographic data with bound ligands is available. The resulting family organization from the
separate analysis of both sites (cofactor and substrate) was retrospectively and prospectively validated. Of note, three
hits (inhibition>50% at 10 µM) were identifed for the orphan NSD1
CHEMDNER: The drugs and chemical names extraction challenge
Natural language processing (NLP) and text mining technologies for the chemical domain (ChemNLP or chemical
text mining) are key to improve the access and integration of information from unstructured data such as patents
or the scientific literature. Therefore, the BioCreative organizers posed the CHEMDNER (chemical compound and
drug name recognition) community challenge, which promoted the development of novel, competitive and
accessible chemical text mining systems. This task allowed a comparative assessment of the performance of various
methodologies using a carefully prepared collection of manually labeled text prepared by specially trained
chemists as Gold Standard data. We evaluated two important aspects: one covered the indexing of documents
with chemicals (chemical document indexing - CDI task), and the other was concerned with finding the exact
mentions of chemicals in text (chemical entity mention recognition - CEM task). 27 teams (23 academic and
4 commercial, a total of 87 researchers) returned results for the CHEMDNER tasks: 26 teams for CEM and 23 for the
CDI task. Top scoring teams obtained an F-score of 87.39% for the CEM task and 88.20% for the CDI task, a very
promising result when compared to the agreement between human annotators (91%). The strategies used to
detect chemicals included machine learning methods (e.g. conditional random fields) using a variety of features,
chemistry and drug lexica, and domain-specific rules. We expect that the tools and resources resulting from this
effort will have an impact in future developments of chemical text mining applications and will form the basis to
find related chemical information for the detected entities, such as toxicological or pharmacogenomic properties
The comparative responsiveness of Hospital Universitario Princesa Index and other composite indices for assessing rheumatoid arthritis activity
Objective
To evaluate the responsiveness in terms of correlation of the Hospital Universitario La Princesa Index (HUPI) comparatively to the traditional composite indices used to assess disease activity in rheumatoid arthritis (RA), and to compare the performance of HUPI-based response criteria with that of the EULAR response criteria.
Methods
Secondary data analysis from the following studies: ACT-RAY (clinical trial), PROAR (early RA cohort) and EMECAR (pre-biologic era long term RA cohort). Responsiveness was evaluated by: 1) comparing change from baseline (Delta) of HUPI with Delta in other scores by calculating correlation coefficients; 2) calculating standardised effect sizes. The accuracy of response by HUPI and by EULAR criteria was analyzed using linear regressions in which the dependent variable was change in global assessment by physician (Delta GDA-Phy).
Results
Delta HUPI correlation with change in all other indices ranged from 0.387 to 0.791); HUPI's standardized effect size was larger than those from the other indices in each database used. In ACT-RAY, depending on visit, between 65 and 80% of patients were equally classified by HUPI and EULAR response criteria. However, HUPI criteria were slightly more stringent, with higher percentage of patients classified as non-responder, especially at early visits. HUPI response criteria showed a slightly higher accuracy than EULAR response criteria when using Delta GDA-Phy as gold standard.
Conclusion
HUPI shows good responsiveness in terms of correlation in each studied scenario (clinical trial, early RA cohort, and established RA cohort). Response criteria by HUPI seem more stringent than EULAR''s
CIBERER : Spanish national network for research on rare diseases: A highly productive collaborative initiative
Altres ajuts: Instituto de Salud Carlos III (ISCIII); Ministerio de Ciencia e Innovación.CIBER (Center for Biomedical Network Research; Centro de Investigación Biomédica En Red) is a public national consortium created in 2006 under the umbrella of the Spanish National Institute of Health Carlos III (ISCIII). This innovative research structure comprises 11 different specific areas dedicated to the main public health priorities in the National Health System. CIBERER, the thematic area of CIBER focused on rare diseases (RDs) currently consists of 75 research groups belonging to universities, research centers, and hospitals of the entire country. CIBERER's mission is to be a center prioritizing and favoring collaboration and cooperation between biomedical and clinical research groups, with special emphasis on the aspects of genetic, molecular, biochemical, and cellular research of RDs. This research is the basis for providing new tools for the diagnosis and therapy of low-prevalence diseases, in line with the International Rare Diseases Research Consortium (IRDiRC) objectives, thus favoring translational research between the scientific environment of the laboratory and the clinical setting of health centers. In this article, we intend to review CIBERER's 15-year journey and summarize the main results obtained in terms of internationalization, scientific production, contributions toward the discovery of new therapies and novel genes associated to diseases, cooperation with patients' associations and many other topics related to RD research
Brain energy rescue:an emerging therapeutic concept for neurodegenerative disorders of ageing
The brain requires a continuous supply of energy in the form of ATP, most of which is produced from glucose by oxidative phosphorylation in mitochondria, complemented by aerobic glycolysis in the cytoplasm. When glucose levels are limited, ketone bodies generated in the liver and lactate derived from exercising skeletal muscle can also become important energy substrates for the brain. In neurodegenerative disorders of ageing, brain glucose metabolism deteriorates in a progressive, region-specific and disease-specific manner — a problem that is best characterized in Alzheimer disease, where it begins presymptomatically. This Review discusses the status and prospects of therapeutic strategies for countering neurodegenerative disorders of ageing by improving, preserving or rescuing brain energetics. The approaches described include restoring oxidative phosphorylation and glycolysis, increasing insulin sensitivity, correcting mitochondrial dysfunction, ketone-based interventions, acting via hormones that modulate cerebral energetics, RNA therapeutics and complementary multimodal lifestyle changes
AI is a viable alternative to high throughput screening: a 318-target study
: High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNet® convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, high-quality X-ray crystal structures, or manual cherry-picking of compounds. We show that the molecules selected by the AtomNet® model are novel drug-like scaffolds rather than minor modifications to known bioactive compounds. Our empirical results suggest that computational methods can substantially replace HTS as the first step of small-molecule drug discovery
The CHEMDNER corpus of chemicals and drugs and its annotation principles
The automatic extraction of chemical information from text requires the recognition of chemical entity mentions as one
of its key steps. When developing supervised named entity recognition (NER) systems, the availability of a large,
manually annotated text corpus is desirable. Furthermore, large corpora permit the robust evaluation and comparison
of different approaches that detect chemicals in documents. We present the CHEMDNER corpus, a collection of 10,000
PubMed abstracts that contain a total of 84,355 chemical entity mentions labeled manually by expert chemistry
literature curators, following annotation guidelines specifically defined for this task. The abstracts of the CHEMDNER
corpus were selected to be representative for all major chemical disciplines. Each of the chemical entity mentions was
manually labeled according to its structure-associated chemical entity mention (SACEM) class: abbreviation, family,
formula, identifier, multiple, systematic and trivial. The difficulty and consistency of tagging chemicals in text was
measured using an agreement study between annotators, obtaining a percentage agreement of 91. For a subset of the
CHEMDNER corpus (the test set of 3,000 abstracts) we provide not only the Gold Standard manual annotations, but also
mentions automatically detected by the 26 teams that participated in the BioCreative IV CHEMDNER chemical mention
recognition task. In addition, we release the CHEMDNER silver standard corpus of automatically extracted mentions
from 17,000 randomly selected PubMed abstracts. A version of the CHEMDNER corpus in the BioC format has been
generated as well. We propose a standard for required minimum information about entity annotations for the
construction of domain specific corpora on chemical and drug entities. The CHEMDNER corpus and annotation
guidelines are available at: http://www.biocreative.org/resources/biocreative-iv/chemdner-corpus
Novel pharmacological maps of protein lysine methyltransferases: key for target deorphanization
Epigenetic therapies are being investigated for the treatment of cancer, cognitive disorders, metabolic alterations and
autoinmune diseases. Among the diferent epigenetic target families, protein lysine methyltransferases (PKMTs), are
especially interesting because it is believed that their inhibition may be highly specifc at the functional level. Despite
its relevance, there are currently known inhibitors against only 10 out of the 50 SET-domain containing members of
the PKMT family. Accordingly, the identifcation of chemical probes for the validation of the therapeutic impact of
epigenetic modulation is key. Moreover, little is known about the mechanisms that dictate their substrate specifcity and ligand selectivity. Consequently, it is desirable to explore novel methods to characterize the pharmacological similarity of PKMTs, going beyond classical phylogenetic relationships. Such characterization would enable the
prediction of ligand of-target efects caused by lack of ligand selectivity and the repurposing of known compounds
against alternative targets. This is particularly relevant in the case of orphan targets with unreported inhibitors. Here,
we frst perform a systematic study of binding modes of cofactor and substrate bound ligands with all available SET
domain-containing PKMTs. Protein ligand interaction fngerprints were applied to identify conserved hot spots and
contact-specifc residues across subfamilies at each binding site; a relevant analysis for guiding the design of novel,
selective compounds. Then, a recently described methodology (GPCR-CoINPocket) that incorporates ligand contact
information into classical alignment-based comparisons was applied to the entire family of 50 SET-containing proteins
to devise pharmacological similarities between them. The main advantage of this approach is that it is not restricted
to proteins for which crystallographic data with bound ligands is available. The resulting family organization from the
separate analysis of both sites (cofactor and substrate) was retrospectively and prospectively validated. Of note, three
hits (inhibition>50% at 10 µM) were identifed for the orphan NSD1
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