163 research outputs found
Cerebrospinal fluid chitinases as biomarkers for Amyotrophic Lateral Sclerosis
© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).Amyotrophic lateral sclerosis (ALS) is a neurodegenerative neuromuscular disease that affects motor neurons controlling voluntary muscles. Survival is usually 2-5 years after onset, and death occurs due to respiratory failure. The identification of biomarkers would be very useful to help in disease diagnosis and for patient stratification based on, e.g., progression rate, with implications in therapeutic trials. Neurofilaments constitute already-promising markers for ALS and, recently, chitinases have emerged as novel marker targets for the disease. Here, we investigated cerebrospinal fluid (CSF) chitinases as potential markers for ALS. Chitotriosidase (CHIT1), chitinase-3-like protein 1 (CHI3L1), chitinase-3-like protein 2 (CHI3L2) and the benchmark marker phosphoneurofilament heavy chain (pNFH) were quantified by an enzyme-linked immunosorbent assay (ELISA) from the CSF of 34 ALS patients and 24 control patients with other neurological diseases. CSF was also analyzed by UHPLC-mass spectrometry. All three chitinases, as well as pNFH, were found to correlate with disease progression rate. Furthermore, CHIT1 was elevated in ALS patients with high diagnostic performance, as was pNFH. On the other hand, CHIT1 correlated with forced vital capacity (FVC). The three chitinases correlated with pNFH, indicating a relation between degeneration and neuroinflammation. In conclusion, our results supported the value of CHIT1 as a diagnostic and progression rate biomarker, and its potential as respiratory function marker. The results opened novel perspectives to explore chitinases as biomarkers and their functional relevance in ALS.We acknowledge iNOVA4Health – UIDB/04462/2020 and UIDP/04462/2020, a program financially supported by Fundação para a Ciência e Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior, through national funds.info:eu-repo/semantics/publishedVersio
Exploring Metabolic Signatures of Ex Vivo Tumor Tissue Cultures for Prediction of Chemosensitivity in Ovarian Cancer
Predicting patient response to treatment and the onset of chemoresistance are still major challenges in oncology. Chemoresistance is deeply influenced by the complex cellular interactions occurring within the tumor microenvironment (TME), including metabolic crosstalk. We have previously shown that ex vivo tumor tissue cultures derived from ovarian carcinoma (OvC) resections retain the TME components for at least four weeks of culture and implemented assays for assessment of drug response. Here, we explored ex vivo patient-derived tumor tissue cultures to uncover metabolic signatures of chemosensitivity and/or resistance. Tissue cultures derived from nine OvC cases were challenged with carboplatin and paclitaxel, the standard-of-care chemotherapeutics, and the metabolic footprints were characterized by LC-MS. Partial least-squares discriminant analysis (PLS-DA) revealed metabolic signatures that discriminated high-responder from low-responder tissue cultures to ex vivo drug exposure. As a proof-of-concept, a set of potential metabolic biomarkers of drug response was identified based on the receiver operating characteristics (ROC) curve, comprising amino acids, fatty acids, pyrimidine, glutathione, and TCA cycle pathways. Overall, this work establishes an analytical and computational platform to explore metabolic features of the TME associated with response to treatment, which can leverage the discovery of biomarkers of drug response and resistance in OvC.publishersversionpublishe
Synaptic Homeostasis and Restructuring across the Sleep-Wake Cycle
Sleep is critical for hippocampus-dependent memory consolidation. However, the underlying
mechanisms of synaptic plasticity are poorly understood. The central controversy is on
whether long-term potentiation (LTP) takes a role during sleep and which would be its specific
effect on memory. To address this question, we used immunohistochemistry to measure
phosphorylation of Ca2+/calmodulin-dependent protein kinase II (pCaMKIIα) in the rat
hippocampus immediately after specific sleep-wake states were interrupted. Control animals
not exposed to novel objects during waking (WK) showed stable pCaMKIIα levels
across the sleep-wake cycle, but animals exposed to novel objects showed a decrease during
subsequent slow-wave sleep (SWS) followed by a rebound during rapid-eye-movement
sleep (REM). The levels of pCaMKIIα during REM were proportional to cortical spindles
near SWS/REM transitions. Based on these results, we modeled sleep-dependent LTP on
a network of fully connected excitatory neurons fed with spikes recorded from the rat hippocampus
across WK, SWS and REM. Sleep without LTP orderly rescaled synaptic weights
to a narrow range of intermediate values. In contrast, LTP triggered near the SWS/REM
transition led to marked swaps in synaptic weight ranking. To better understand the interaction
between rescaling and restructuring during sleep, we implemented synaptic homeostasis
and embossing in a detailed hippocampal-cortical model with both excitatory and
inhibitory neurons. Synaptic homeostasis was implemented by weakening potentiation
and strengthening depression, while synaptic embossing was simulated by evoking LTP
on selected synapses. We observed that synaptic homeostasis facilitates controlled
synaptic restructuring. The results imply a mechanism for a cognitive synergy between
SWS and REM, and suggest that LTP at the SWS/REM transition critically influences the effect
of sleep: Its lack determines synaptic homeostasis, its presence causes synaptic
restructuring.: Support obtained from Financiadora de
Estudos e Projetos (http://www.finep.gov.br/) Grant #
01.06.1092.00 to SR; Conselho Nacional de
Desenvolvimento Científico e Tecnológico (http://
www.cnpq.br/): Grants 481506/2007-1, 481351/2011-
6 and 306604/2012-4 to SR, Coordenação de
Aperfeiçoamento de Pessoal de Nível Superior
(http://www.capes.gov.br/) and Ciencias sem
Fronteiras (http://www.cienciasemfronteiras.gov.br/
web/csf/home) to AT and CRC; Fundação de Amparo
à Pesquisa do Rio Grande do Norte (http://wwwfapern.rn.gov.br/): Grant Pronem 003/2011 to SR;
Fundação de Amparo à Pesquisa do Estado de São
Paulo (http://www.fapesp.br/): Grant #2013/ 07699-0 -
Center for Neuromathematics to SR; CMP and VRC
supported by post-doctoral fellowships from
Fundação de Amparo à Pesquisa do Rio Grande do
Norte /CNPq. Additional support obtained from the
Federal University of Rio Grande do Norte (www.ufrn.
br); Ministry of Science, Technology and Innovation
(http://www.mcti.gov.br/); Associação Alberto Santos
Dumont de Apoio à Pesquisa (http://natalneuro.com/
associacao/index.asp); Pew Latin American Fellows
Program (http://www.pewtrusts.org/en/projects/pewlatin-american-fellows/)
to SR; Informatics
Department of the Instituto Federal de Educação,
Ciência e Tecnologia do Rio Grande do Norte (http://
portal.ifrn.edu.br/) to WB. The funders had no role in
study design, data collection and analysis, decision to
publish, or preparation of the manuscrip
Metabolomics profile responses to changing environments in a common bean (Phaseolus vulgaris L.) germplasm collection
Metabolomics is one of the most powerful -omics to assist plant breeding. Despite the recognized genetic diversity in Portuguese common bean germplasm, details on its metabolomics profiles are still missing. Aiming to promote their use and to understand the environment’s effect in bean metabolomics profiles, 107 Portuguese common bean accessions, cropped under contrasting environments, were analyzed using spectrophotometric, untargeted and targeted mass spectrometry approaches. Although genotype was the most relevant factor on bean metabolomics profile, a clear genotype × environment interaction was also detected. Multivariate analysis highlighted, on the heat-stress environment, the existence of higher levels of salicylic acid, and lower levels of triterpene saponins. Three clusters were defined within each environment. White accessions presented the lowest content and the colored ones the highest levels of prenol lipids and flavonoids. Sources of interesting metabolomics profiles are now identified for bean breeding, focusing either on local or on broad adaptation.To FCT, Portugal, in BEGEQA project (PTDC/AGR-TEC/3555/2012), E.M. PhD fellowship (SFRH/BD/89287/2012), as well as to R&D unit, UIDB/04551/2020 (GREEN-IT – Bioresources for sustainability) and COST Action FA1403 (STSM-FA1403-290815-063873) for funding. The authors also acknowledge PORTUGAL 2020 to the Portuguese Mass Spectrometry Network, grant number LISBOA-01-0145-FEDER-402-022125. The project NETDIAMOND (SAICTPAC/0047/2015), financially supported by FEEI (Lisboa 2020 and FCT/POCI-01-0145-FEDER-016385), to the iNOVA4Health (UID/Multi/04462/2013), financially supported by FCT and co-funded by FEDER under the PT2020 Partnership Agreement, as well as to POCI-01-0145-FEDER-029702, funded by FEDER funds through COMPETE2020 – Programa Operacional Competitividade e Internacionalização (POCI) and by national funds (PIDDAC) through FCT/MCTES
Predicting progression of mild cognitive impairment to dementia using neuropsychological data: a supervised learning approach using time windows
Background: Predicting progression from a stage of Mild Cognitive Impairment to dementia is a major pursuit in current research. It is broadly accepted that cognition declines with a continuum between MCI and dementia. As such, cohorts of MCI patients are usually heterogeneous, containing patients at different stages of the neurodegenerative process. This hampers the prognostic task. Nevertheless, when learning prognostic models, most studies use the entire cohort of MCI patients regardless of their disease stages. In this paper, we propose a Time Windows approach to predict conversion to dementia, learning with patients stratified using time windows, thus fine-tuning the prognosis regarding the time to conversion. Methods: In the proposed Time Windows approach, we grouped patients based on the clinical information of whether they converted (converter MCI) or remained MCI (stable MCI) within a specific time window. We tested time windows of 2, 3, 4 and 5 years. We developed a prognostic model for each time window using clinical and neuropsychological data and compared this approach with the commonly used in the literature, where all patients are used to learn the models, named as First Last approach. This enables to move from the traditional question "Will a MCI patient convert to dementia somewhere in the future" to the question "Will a MCI patient convert to dementia in a specific time window". Results: The proposed Time Windows approach outperformed the First Last approach. The results showed that we can predict conversion to dementia as early as 5 years before the event with an AUC of 0.88 in the cross-validation set and 0.76 in an independent validation set. Conclusions: Prognostic models using time windows have higher performance when predicting progression from MCI to dementia, when compared to the prognostic approach commonly used in the literature. Furthermore, the proposed Time Windows approach is more relevant from a clinical point of view, predicting conversion within a temporal interval rather than sometime in the future and allowing clinicians to timely adjust treatments and clinical appointments.FCT under the Neuroclinomics2 project [PTDC/EEI-SII/1937/2014, SFRH/BD/95846/2013]; INESC-ID plurianual [UID/CEC/50021/2013]; LASIGE Research Unit [UID/CEC/00408/2013
Burden, coping, physical symptoms and psychological morbidity in caregivers of functionally dependent family members
Objectives: this study assessed burden, coping, physical symptoms and psychological morbidity in caregivers of functionally dependent family members. Methods: fifty family caregivers
completed self-reported measures of burden, physical symptoms, psychological morbidity and coping strategies. Results: there was a significant negative correlation between coping strategies and the different clinical variables, as well as a significant positive correlation between coping
strategies and duration of care. It appears that the stronger bond between caregiver and family member leads to a poorer use of adaptive coping strategies. It also appears that the deterioration of the relationship between them and the lower perceived self-efficacy are more prominente in caregivers of family members with cognitive impairment, indicating that caregivers with
family members without cognitive impairment face fewer difficulties. Conclusion: these results emphasize the need for interventions to include coping strategies, since they are important in
reducing caregivers’ burden, psychological morbidity and physical symptoms
Allosteric Antagonist Modulation of TRPV2 by Piperlongumine Impairs Glioblastoma Progression.
The use of computational tools to identify biological targets of natural products with anticancer properties and unknown modes of action is gaining momentum. We employed self-organizing maps to deconvolute the phenotypic effects of piperlongumine (PL) and establish a link to modulation of the human transient receptor potential vanilloid 2 (hTRPV2) channel. The structure of the PL-bound full-length rat TRPV2 channel was determined by cryo-EM. PL binds to a transient allosteric pocket responsible for a new mode of anticancer activity against glioblastoma (GBM) in which hTRPV2 is overexpressed. Calcium imaging experiments revealed the importance of Arg539 and Thr522 residues on the antagonistic effect of PL and calcium influx modulation of the TRPV2 channel. Downregulation of hTRPV2 reduces sensitivity to PL and decreases ROS production. Analysis of GBM patient samples associates hTRPV2 overexpression with tumor grade, disease progression, and poor prognosis. Extensive tumor abrogation and long term survival was achieved in two murine models of orthotopic GBM by formulating PL in an implantable scaffold/hydrogel for sustained local therapy. Furthermore, in primary tumor samples derived from GBM patients, we observed a selective reduction of malignant cells in response to PL ex vivo. Our results establish a broadly applicable strategy, leveraging data-motivated research hypotheses for the discovery of novel means tackling cancer
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