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Type 2 cytokines like IL-4 are hallmarks of helminth infection and activate macrophages to limit immunopathology and mediate helminth clearance. In addition to cytokines, nutrients and metabolites critically influence macrophage polarization. Choline is an essential nutrient known to support normal macrophage responses to lipopolysaccharide; however, its function in macrophages polarized by type 2 cytokines is unknown. Using murine IL-4-polarized macrophages, targeted lipidomics revealed significantly elevated levels of phosphatidylcholine, with select changes to other choline-containing lipid species. These changes were supported by the coordinated up-regulation of choline transport compared to naïve macrophages. Pharmacological inhibition of choline metabolism significantly suppressed several mitochondrial transcripts and dramatically inhibited select IL-4-responsive transcripts, most notably, Retnla. We further confirmed that blocking choline metabolism diminished IL-4-induced RELMα (encoded by Retnla) protein content and secretion and caused a dramatic reprogramming toward glycolytic metabolism. To better understand the physiological implications of these observations, naïve or mice infected with the intestinal helminth Heligmosomoides polygyrus were treated with the choline kinase α inhibitor, RSM-932A, to limit choline metabolism in vivo. Pharmacological inhibition of choline metabolism lowered RELMα expression across cell-types and tissues and led to the disappearance of peritoneal macrophages and B-1 lymphocytes and an influx of infiltrating monocytes. The impaired macrophage activation was associated with some loss in optimal immunity to H. polygyrus, with increased egg burden. Together, these data demonstrate that choline metabolism is required for macrophage RELMα induction, metabolic programming, and peritoneal immune homeostasis, which could have important implications in the context of other models of infection or cancer immunity.
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Interleucina-4 , Activación de Macrófagos , Animales , Ratones , Colina/metabolismo , Citocinas/metabolismo , Interleucina-4/metabolismo , Macrófagos , Ratones Endogámicos C57BL , Regulación hacia ArribaRESUMEN
MOTIVATION: There is a need for easily accessible implementations that measure the strength of both linear and non-linear relationships between metabolites in biological systems as an approach for data-driven network development. While multiple tools implement linear Pearson and Spearman methods, there are no such tools that assess distance correlation. RESULTS: We present here SIgned Distance COrrelation (SiDCo). SiDCo is a GUI platform for calculation of distance correlation in omics data, measuring linear and non-linear dependencies between variables, as well as correlation between vectors of different lengths, e.g. different sample sizes. By combining the sign of the overall trend from Pearson's correlation with distance correlation values, we further provide a novel "signed distance correlation" of particular use in metabolomic and lipidomic analyses. Distance correlations can be selected as one-to-one or one-to-all correlations, showing relationships between each feature and all other features one at a time or in combination. Additionally, we implement "partial distance correlation," calculated using the Gaussian Graphical model approach adapted to distance covariance. Our platform provides an easy-to-use software implementation that can be applied to the investigation of any dataset. AVAILABILITY AND IMPLEMENTATION: The SiDCo software application is freely available at https://complimet.ca/sidco. Supplementary help pages are provided at https://complimet.ca/sidco. Supplementary Material shows an example of an application of SiDCo in metabolomics.
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Metabolómica , Programas Informáticos , Lipidómica , Distribución Normal , Tamaño de la MuestraRESUMEN
MOTIVATION: Class imbalance, or unequal sample sizes between classes, is an increasing concern in machine learning for metabolomic and lipidomic data mining, which can result in overfitting for the over-represented class. Numerous methods have been developed for handling class imbalance, but they are not readily accessible to users with limited computational experience. Moreover, there is no resource that enables users to easily evaluate the effect of different over-sampling algorithms. RESULTS: METAbolomics data Balancing with Over-sampling Algorithms (META-BOA) is a web-based application that enables users to select between four different methods for class balancing, followed by data visualization and classification of the sample to observe the augmentation effects. META-BOA outputs a newly balanced dataset, generating additional samples in the minority class, according to the user's choice of Synthetic Minority Over-sampling Technique (SMOTE), Borderline-SMOTE (BSMOTE), Adaptive Synthetic (ADASYN) or Random Over-Sampling Examples (ROSE). To present the effect of over-sampling on the data META-BOA further displays both principal component analysis and t-distributed stochastic neighbor embedding visualization of data pre- and post-over-sampling. Random forest classification is utilized to compare sample classification in both the original and balanced datasets, enabling users to select the most appropriate method for their further analyses. AVAILABILITY AND IMPLEMENTATION: META-BOA is available at https://complimet.ca/meta-boa. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
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Algoritmos , Aprendizaje Automático , Minería de Datos , MetabolómicaRESUMEN
MOTIVATION: Bioinformatic tools capable of annotating, rapidly and reproducibly, large, targeted lipidomic datasets are limited. Specifically, few programs enable high-throughput peak assessment of liquid chromatography-electrospray ionization tandem mass spectrometry data acquired in either selected or multiple reaction monitoring modes. RESULTS: We present here Bayesian Annotations for Targeted Lipidomics, a Gaussian naïve Bayes classifier for targeted lipidomics that annotates peak identities according to eight features related to retention time, intensity, and peak shape. Lipid identification is achieved by modeling distributions of these eight input features across biological conditions and maximizing the joint posterior probabilities of all peak identities at a given transition. When applied to sphingolipid and glycerophosphocholine selected reaction monitoring datasets, we demonstrate over 95% of all peaks are rapidly and correctly identified. AVAILABILITY AND IMPLEMENTATION: BATL software is freely accessible online at https://complimet.ca/batl/ and is compatible with Safari, Firefox, Chrome and Edge. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
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Lipidómica , Programas Informáticos , Teorema de Bayes , Espectrometría de Masas , Cromatografía Liquida/métodosRESUMEN
BACKGROUND: Although men and women with the LRRK2 G2019S variant appear to be equally likely to have Parkinson's disease (PD), the sex-distribution among glucocerebrosidase (GBA) variant carriers with PD, including limited to specific variant severities of GBA, is not well understood. Further, the sex-specific genetic contribution to PD without a known genetic variant is controversial. OBJECTIVES: To better understand sex differences in genetic contribution to PD, especially sex-specific frequencies among GBA variant carriers with PD (GBA PD) and LRRK2-G2019S variant carriers with PD (LRRK2 PD). METHODS: We assess differences in the sex-specific frequency in GBA PD, including in subsets of GBA variant severity, LRRK2 PD, and idiopathic PD in an Ashkenazi Jewish cohort with PD. Further, we expand prior work evaluating differences in family history of parkinsonism. RESULTS: Both idiopathic PD (267/420 men, 63.6%) (P < 0.001) and GBA PD overall (64/107, 59.8%) (P = 0.042) were more likely to be men, whereas no difference was seen in LRRK2 PD (50/99, 50.5%) and LRRK2/GBA PD (5/10, 50%). However, among GBA PD probands, severe variant carriers were more likely to be women (15/19 women, 79.0%) (P = 0.005), whereas mild variant carriers (44/70 men, 62.9%) (P = 0.039) and risk-variant carriers (15/17 men, 88.2%) (P = 0.001) were more likely to be men. CONCLUSIONS: Our study demonstrates that the male-sex predominance present in GBA PD overall was not consistent across GBA variant severities, and a female-sex predominance was present among severe GBA variant carriers. Therefore, research and trial designs for PD should consider sex-specific differences, including across GBA variant severities. © 2022 International Parkinson and Movement Disorder Society.
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Glucosilceramidasa , Enfermedad de Parkinson , Femenino , Masculino , Humanos , Glucosilceramidasa/genética , Proteína 2 Quinasa Serina-Treonina Rica en Repeticiones de Leucina/genética , Mutación , Heterocigoto , Enfermedad de Parkinson/genéticaRESUMEN
While the COVID-19 pandemic is causing important loss of life, knowledge of the effects of the causative SARS-CoV-2 virus on human cells is currently limited. Investigating protein-protein interactions (PPIs) between viral and host proteins can provide a better understanding of the mechanisms exploited by the virus and enable the identification of potential drug targets. We therefore performed an in-depth computational analysis of the interactome of SARS-CoV-2 and human proteins in infected HEK 293 cells published by Gordon et al. (Nature2020, 583, 459-468) to reveal processes that are potentially affected by the virus and putative protein binding sites. Specifically, we performed a set of network-based functional and sequence motif enrichment analyses on SARS-CoV-2-interacting human proteins and on PPI networks generated by supplementing viral-host PPIs with known interactions. Using a novel implementation of our GoNet algorithm, we identified 329 Gene Ontology terms for which the SARS-CoV-2-interacting human proteins are significantly clustered in PPI networks. Furthermore, we present a novel protein sequence motif discovery approach, LESMoN-Pro, that identified 9 amino acid motifs for which the associated proteins are clustered in PPI networks. Together, these results provide insights into the processes and sequence motifs that are putatively implicated in SARS-CoV-2 infection and could lead to potential therapeutic targets.
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Betacoronavirus , Infecciones por Coronavirus , Interacciones Huésped-Patógeno/genética , Pandemias , Neumonía Viral , Mapas de Interacción de Proteínas , Algoritmos , Secuencias de Aminoácidos , Betacoronavirus/química , Betacoronavirus/metabolismo , Betacoronavirus/patogenicidad , COVID-19 , Análisis por Conglomerados , Infecciones por Coronavirus/metabolismo , Infecciones por Coronavirus/virología , Ontología de Genes , Células HEK293 , Humanos , Anotación de Secuencia Molecular , Neumonía Viral/metabolismo , Neumonía Viral/virología , Unión Proteica , Mapas de Interacción de Proteínas/genética , Mapas de Interacción de Proteínas/fisiología , Proteínas/química , Proteínas/clasificación , Proteínas/genética , Proteínas/metabolismo , SARS-CoV-2 , Proteínas Virales/química , Proteínas Virales/genética , Proteínas Virales/metabolismoRESUMEN
Cerebrosides, including glucosylceramides (GlcCers) and galactosylceramides (GalCers), are important membrane components of animal cells with deficiencies resulting in devastating lysosomal storage disorders. Their quantification is essential for disease diagnosis and a better understanding of disease mechanisms. The simultaneous quantification of GlcCer and GalCer isomers is, however, particularly challenging due to their virtually identical structures. To address this challenge, we developed a new LC/MS-based method using differential ion mobility spectrometry (DMS) capable of rapidly and reproducibly separating and quantifying isomeric cerebrosides in a single run. We show that this LC/ESI/DMS/MS/MS method exhibits robust quantitative performance within an analyte concentration range of 2.8-355 nM. We further report the simultaneous quantification of nine GlcCers (16:0, 18:0, 20:0, 22:0, 23:0, 24:1, 24:0, 25:0, and 26:0) and five GalCers (16:0, 22:0, 23:0, 24:1, and 24:0) molecular species in human plasma, as well as six GalCers (18:0, 22:0, 23:0, 24:1, 24:0 and 25:0) and two GlcCers (24:1 and 24:0) in human cerebrospinal fluid. Our method expands the potential of DMS technology in the field of glycosphingolipid analysis for both biomarker discovery and drug screening by enabling the unambiguous assignment and quantification of cerebroside lipid species in biological samples.
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Cerebrósidos/química , Cerebrósidos/aislamiento & purificación , Cromatografía Liquida/métodos , Espectrometría de Movilidad Iónica/métodos , Espectrometría de Masa por Ionización de Electrospray/métodos , Espectrometría de Masas en Tándem/métodos , Cerebrósidos/sangre , Cerebrósidos/líquido cefalorraquídeo , Cromatografía Liquida/normas , Femenino , Humanos , Espectrometría de Movilidad Iónica/normas , Isomerismo , Persona de Mediana Edad , Estándares de Referencia , Espectrometría de Masa por Ionización de Electrospray/normas , Espectrometría de Masas en Tándem/normas , Factores de TiempoRESUMEN
Choline is an essential nutrient that is required for synthesis of the main eukaryote phospholipid, phosphatidylcholine. Macrophages are innate immune cells that survey and respond to danger and damage signals. Although it is well-known that energy metabolism can dictate macrophage function, little is known as to the importance of choline homeostasis in macrophage biology. We hypothesized that the uptake and metabolism of choline are important for macrophage inflammation. Polarization of primary bone marrow macrophages with lipopolysaccharide (LPS) resulted in an increased rate of choline uptake and higher levels of PC synthesis. This was attributed to a substantial increase in the transcript and protein expression of the choline transporter-like protein-1 (CTL1) in polarized cells. We next sought to determine the importance of choline uptake and CTL1 for macrophage immune responsiveness. Chronic pharmacological or CTL1 antibody-mediated inhibition of choline uptake resulted in altered cytokine secretion in response to LPS, which was associated with increased levels of diacylglycerol and activation of protein kinase C. These experiments establish a previously unappreciated link between choline phospholipid metabolism and macrophage immune responsiveness, highlighting a critical and regulatory role for macrophage choline uptake via the CTL1 transporter.
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Colina/metabolismo , Inflamación/metabolismo , Macrófagos/metabolismo , Fosfolípidos/metabolismo , Animales , Células Cultivadas , Inflamación/patología , Lipogénesis , Macrófagos/patología , Ratones Endogámicos C57BL , Proteínas de Transporte de Catión Orgánico/metabolismoRESUMEN
Changes in glycerophosphocholine metabolism are observed in Alzheimer's disease; however, it is not known whether these metabolic disruptions are linked to cognitive decline. Here, using unbiased lipidomic approaches and direct biochemical assessments, we profiled Land's cycle lipid remodeling in the hippocampus, frontal cortex, and temporal-parietal-entorhinal cortices of human amyloid beta precursor protein (ΑßPP) over-expressing mice. We identified a cortex-specific hypo-metabolic signature at symptomatic onset and a cortex-specific hyper-metabolic signature of Land's cycle glycerophosphocholine remodeling over the course of progressive behavioral decline. When N5 TgCRND8 and ΑßPPSwe /PSIdE9 mice first exhibited deficits in the Morris Water Maze, levels of lyso-phosphatidylcholines, LPC(18:0/0:0), LPC(16:0/0:0), LPC(24:6/0:0), LPC(25:6/0:0), the lyso-platelet-activating factor (PAF), LPC(O-18:0/0:0), and the PAF, PC(O-22:6/2:0), declined as a result of reduced calcium-dependent cytosolic phospholipase A2 α (cPLA2 α) activity in all cortices but not hippocampus. Chronic intermittent hypoxia, an environmental risk factor that triggers earlier learning memory impairment in ΑßPPSwe /PSIdE9 mice, elicited these same metabolic changes in younger animals. Thus, this lipidomic signature of phenoconversion appears age-independent. By contrast, in symptomatic N5 TgCRND8 mice, cPLA2 α activity progressively increased; overall Lyso-phosphatidylcholines (LPC) and LPC(O) and PC(O-18:1/2:0) levels progressively rose. Enhanced cPLA2 α activity was only detected in transgenic mice; however, age-dependent increases in the PAF acetylhydrolase 1b α1 to α2 expression ratio, evident in both transgenic and non-transgenic mice, reduced PAF hydrolysis thereby contributing to PAF accumulation. Taken together, these data identify distinct age-independent and age-dependent disruptions in Land's cycle metabolism linked to symptomatic onset and progressive behavioral decline in animals with pre-existing Αß pathology. OPEN SCIENCE BADGES: This article has received a badge for *Open Materials* because it provided all relevant information to reproduce the study in the manuscript. The complete Open Science Disclosure form for this article can be found at the end of the article. More information about the Open Practices badges can be found at https://cos.io/our-services/open-science-badges/.
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Enfermedad de Alzheimer/metabolismo , Corteza Cerebral/metabolismo , Fosfatidilcolinas/metabolismo , Precursor de Proteína beta-Amiloide/toxicidad , Animales , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Humanos , RatonesRESUMEN
BACKGROUND: The Cree of Eeyou Istchee (James Bay area of northern Quebec) suffer from a high rate of diabetes and its complications partly due to the introduction of the western lifestyle within their culture. As part of a search for alternative medicine based on traditional practice, this project evaluates the biological activity of Picea mariana (Mill.) Britton, Sterns & Poggenb. needle, bark, and cone, in preventing glucose toxicity to PC12-AC cells in vitro (a diabetic neurophathy model) and whether habitat and growth environment influence this activity. METHODS: Three different organs (needle, bark, and cone) of P. mariana were collected at different geographical locations and ecological conditions and their 80% ethanolic extracts were prepared. Extracts were then tested for their ability to protect PC12-AC cells from hyperglycaemic challenge at physiologically relevant concentrations of 0.25, 0.5, 1.0 and 2.0 µg/mL. Folin-Ciocalteu method was used to determine the total phenolic content of P. mariana extracts. RESULTS: All extracts were well-tolerated in vitro exhibiting LD50 of 25 µg/mL or higher. Extracts from all tested organs showed a cytoprotective concentration-dependent response. Furthermore, the cytoprotective activity was habitat- and growth environment-dependent with plants grown in bog or forest habitats in coastal or inland environments exhibiting different cytoprotective efficacies. These differences in activity correlated with total phenolic content but not with antioxidant activity. In addition, this paper provides the first complete Ultra-Performance Liquid Chromatography-quadrupole time-of-flight (UPLC-QTOF) mass spectrometry analysis of Picea mariana's bark, needles and cones. CONCLUSIONS: Together, these results provide further understanding of the cytoprotective activity of Canadian boreal forest plants identified by the Cree healers of Eeyou Istchee in a cell model of diabetic neuropathy. Their activity is relevant to diabetic peripheral neuropathic complications and shows that their properties can be optimized by harvesting in optimal growth environments.
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Diabetes Mellitus/fisiopatología , Glucosa/toxicidad , Hipoglucemiantes/farmacología , Picea/química , Extractos Vegetales/farmacología , Sustancias Protectoras/farmacología , Animales , Supervivencia Celular/efectos de los fármacos , Diabetes Mellitus/tratamiento farmacológico , Diabetes Mellitus/metabolismo , Glucosa/metabolismo , Hipoglucemiantes/análisis , Células PC12 , Extractos Vegetales/análisis , Sustancias Protectoras/análisis , Quebec , RatasRESUMEN
At least 15% of the disease-causing mutations affect mRNA splicing. Many splicing mutations are missed in a clinical setting due to limitations of in silico prediction algorithms or their location in noncoding regions. Whole-transcriptome sequencing is a promising new tool to identify these mutations; however, it will be a challenge to obtain disease-relevant tissue for RNA. Here, we describe an individual with a sporadic atypical spinal muscular atrophy, in whom clinical DNA sequencing reported one pathogenic ASAH1 mutation (c.458A>G;p.Tyr153Cys). Transcriptome sequencing on patient leukocytes identified a highly significant and atypical ASAH1 isoform not explained by c.458A>G(p<10-16 ). Subsequent Sanger-sequencing identified the splice mutation responsible for the isoform (c.504A>C;p.Lys168Asn) and provided a molecular diagnosis of autosomal-recessive spinal muscular atrophy with progressive myoclonic epilepsy. Our findings demonstrate the utility of RNA sequencing from blood to identify splice-impacting disease mutations for nonhematological conditions, providing a diagnosis for these otherwise unsolved patients.
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Ceramidasa Ácida/genética , Atrofia Muscular Espinal/sangre , Epilepsias Mioclónicas Progresivas/sangre , Empalme del ARN/genética , Ceramidasa Ácida/sangre , Preescolar , Humanos , Masculino , Atrofia Muscular Espinal/complicaciones , Atrofia Muscular Espinal/genética , Mutación , Epilepsias Mioclónicas Progresivas/complicaciones , Epilepsias Mioclónicas Progresivas/genética , Patología Molecular , Análisis de Secuencia de ADN , Transcriptoma/genéticaRESUMEN
Braak and Del Tredici have proposed that typical Parkinson disease (PD) has its origins in the olfactory bulb and gastrointestinal tract. However, the role of the olfactory system has insufficiently been explored in the pathogeneses of PD and Alzheimer disease (AD) in laboratory models. Here, we demonstrate applications of a new method to process mouse heads for microscopy by sectioning, mounting, and staining whole skulls ('holocranohistochemistry'). This technique permits the visualization of the olfactory system from the nasal cavity to mitral cells and dopamine-producing interneurons of glomeruli in the olfactory bulb. We applied this method to two specific goals: first, to visualize PD- and AD-linked gene expression in the olfactory system, where we detected abundant, endogenous α-synuclein and tau expression in the olfactory epithelium. Furthermore, we observed amyloid-ß plaques and proteinase-K-resistant α-synuclein species, respectively, in cranial nerve-I of APP- and human SNCA-over-expressing mice. The second application of the technique was to the modeling of gene-environment interactions in the nasal cavity of mice. We tracked the infection of a neurotropic respiratory-enteric-orphan virus from the nose pad into cranial nerves-I (and -V) and monitored the ensuing brain infection. Given its abundance in the olfactory epithelia, we questioned whether α-synuclein played a role in innate host defenses to modify the outcome of infections. Indeed, Snca-null mice were more likely to succumb to viral encephalitis versus their wild-type littermates. Moreover, using a bacterial sepsis model, Snca-null mice were less able to control infection after intravenous inoculation with Salmonella typhimurium. Together, holocranohistochemistry enabled new discoveries related to α-synuclein expression and its function in mice. Future studies will address: the role of Mapt and mutant SNCA alleles in infection paradigms; the contribution of xenobiotics in the initiation of idiopathic PD; and the safety to the host when systemically targeting α-synuclein by immunotherapy.
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Encéfalo/metabolismo , Encéfalo/virología , Encefalitis Viral/virología , Mucosa Olfatoria/anatomía & histología , Mucosa Olfatoria/metabolismo , Infecciones por Reoviridae/virología , alfa-Sinucleína/metabolismo , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animales , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Modelos Animales de Enfermedad , Encefalitis Viral/inmunología , Encefalitis Viral/mortalidad , Encefalitis Viral/patología , Femenino , Cabeza , Humanos , Inmunohistoquímica , Masculino , Orthoreovirus Mamífero 3 , Ratones , Ratones de la Cepa 129 , Ratones Endogámicos C57BL , Ratones Transgénicos , Vías Nerviosas/anatomía & histología , Vías Nerviosas/diagnóstico por imagen , Vías Nerviosas/metabolismo , Vías Nerviosas/patología , Mucosa Olfatoria/patología , Neuronas Receptoras Olfatorias/metabolismo , Neuronas Receptoras Olfatorias/virología , Infecciones por Reoviridae/inmunología , Infecciones por Salmonella/inmunología , Infecciones por Salmonella/patología , Salmonella typhimurium , Conservación de Tejido/métodos , alfa-Sinucleína/genéticaRESUMEN
Unbiased lipidomic approaches have identified impairments in glycerophosphocholine second messenger metabolism in patients with Alzheimer's disease. Specifically, we have shown that amyloid-ß42 signals the intraneuronal accumulation of PC(O-16:0/2:0) which is associated with neurotoxicity. Similar to neuronal cells, intracellular accumulation of PC(O-16:0/2:0) is also toxic to Saccharomyces cerevisiae, making yeast an excellent model to decipher the pathological effects of this lipid. We previously reported that phospholipase D, a phosphatidylinositol-4,5-bisphosphate (PtdIns(4,5)P2)-binding protein, was relocalized in response to PC(O-16:0/2:0), suggesting that this neurotoxic lipid may remodel lipid signaling networks. Here we show that PC(O-16:0/2:0) regulates the distribution of the PtdIns(4)P 5-kinase Mss4 and its product PtdIns(4,5)P2 leading to the formation of invaginations at the plasma membrane (PM). We further demonstrate that the effects of PC(O-16:0/2:0) on the distribution of PM PtdIns(4,5)P2 pools are in part mediated by changes in the biosynthesis of long chain bases (LCBs) and ceramides. A combination of genetic, biochemical and cell imaging approaches revealed that PC(O-16:0/2:0) is also a potent inhibitor of signaling through the Target of rampamycin complex 2 (TORC2). Together, these data provide mechanistic insight into how specific disruptions in phosphocholine second messenger metabolism associated with Alzheimer's disease may trigger larger network-wide disruptions in ceramide and phosphoinositide second messenger biosynthesis and signaling which have been previously implicated in disease progression.
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Enfermedad de Alzheimer/metabolismo , Complejos Multiproteicos/metabolismo , Fosfatidilinositol 4,5-Difosfato/metabolismo , Fosforilcolina/toxicidad , Serina-Treonina Quinasas TOR/metabolismo , Enfermedad de Alzheimer/etiología , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/metabolismo , Membrana Celular/efectos de los fármacos , Ceramidas/biosíntesis , Humanos , Diana Mecanicista del Complejo 2 de la Rapamicina , Complejos Multiproteicos/biosíntesis , Neuronas/efectos de los fármacos , Fosfotransferasas (Aceptor de Grupo Alcohol)/biosíntesis , Saccharomyces cerevisiae , Proteínas de Saccharomyces cerevisiae/biosíntesis , Transducción de Señal/efectos de los fármacos , Serina-Treonina Quinasas TOR/biosíntesisRESUMEN
Connexins and pannexins share very similar structures and functions; they also exhibit overlapping expression in many stages of neuronal development. Here, we review evidence implicating connexin- and pannexin-mediated communication in the regulation of the birth and development of neurons, specifically Cx26, Cx30, Cx32, Cx36, Cx43, Cx45, Panx1, and Panx2. We begin by dissecting the involvement of these proteins in the generation and development of new neurons in the embryonic, postnatal, and adult brain. Next we briefly outline common mechanisms employed by both pannexins and connexins in these roles, including modulation of purinergic receptor signalling and signalling nexus functions. Throughout this review we highlight developing themes as well as important gaps in knowledge to be bridged.
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Conexinas/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Neurogénesis , Neuronas/citología , Adulto , Animales , Encéfalo/citología , Humanos , Células-Madre Neurales/citología , Células-Madre Neurales/metabolismo , Neuronas/metabolismoRESUMEN
The mechanisms underlying disparate roles of the canonical Wnt signaling pathway in maintaining self-renewal or inducing differentiation and lineage specification in embryonic stem cells (ESCs) are not clear. In this study, we provide the first demonstration that self-renewal versus differentiation of human ESCs (hESCs) in response to Wnt signaling is predominantly determined by a two-layer regulatory circuit involving ß-catenin, E-cadherin, PI3K/Akt, and Slug in a time-dependent manner. Short-term upregulation of ß-catenin does not lead to the activation of T-cell factor (TCF)-eGFP Wnt reporter in hESCs. Instead, it enhances E-cadherin expression on the cell membrane, thereby enhancing hESC self-renewal through E-cadherin-associated PI3K/Akt signaling. Conversely, long-term Wnt activation or loss of E-cadherin intracellular ß-catenin binding domain induces TCF-eGFP activity and promotes hESC differentiation through ß-catenin-induced upregulation of Slug. Enhanced expression of Slug leads to a further reduction of E-cadherin that serves as a ß-catenin "sink" sequestering free cytoplasmic ß-catenin. The formation of such a framework reinforces hESCs to switch from a state of temporal self-renewal associated with short-term Wnt/ß-catenin activation to definitive differentiation. Stem Cells 2015;33:1419-1433.
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Cadherinas/metabolismo , Diferenciación Celular , Redes Reguladoras de Genes , Fosfatidilinositol 3-Quinasas/metabolismo , Células Madre Pluripotentes/citología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Factores de Transcripción/metabolismo , beta Catenina/metabolismo , Diferenciación Celular/efectos de los fármacos , Autorrenovación de las Células/efectos de los fármacos , Regulación hacia Abajo/efectos de los fármacos , Activación Enzimática/efectos de los fármacos , Redes Reguladoras de Genes/efectos de los fármacos , Glucógeno Sintasa Quinasa 3/antagonistas & inhibidores , Glucógeno Sintasa Quinasa 3/metabolismo , Humanos , Células Madre Pluripotentes/efectos de los fármacos , Inhibidores de Proteínas Quinasas/farmacología , Factores de Transcripción de la Familia Snail , Factores de Transcripción TCF/metabolismo , Regulación hacia Arriba/efectos de los fármacos , Vía de Señalización Wnt/efectos de los fármacosRESUMEN
PURPOSE: The purpose of this study was to assess safety of the traditional antidiabetic extracts of either S. purpurea or its lead active principle, morroniside at the transcriptional level. The overarching objective was to profile and validate transcriptional changes in the cytochrome P450 family of genes, in response to treatment with S. purpurea ethanolic extract or its lead active, morroniside. METHODS: Transcriptional activity was profiled using a 19K human cDNA microarray in C2BBe1 cells, clone of Caco-2 intestinal cells, which are a model of first-pass metabolism (1, 2). Cells were treated with S. purpurea extract for 4 and 24 hrs, as well as the pure compound morroniside for 4 hrs, to determine their effects. RESULTS: No evidence of cytochrome P450 transcriptome regulation or of transcriptional activation of other diabetes relevant mRNA was detected after rigorous quantitative-PCR validation of microarray results. CONCLUSION: Our data do not support a transcriptional mechanism of action for either S. purpurea extract or its lead active, morroniside. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.
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Sistema Enzimático del Citocromo P-450/genética , Glicósidos/toxicidad , Extractos Vegetales/toxicidad , Sarraceniaceae/química , Células CACO-2 , ADN Complementario/genética , Glicósidos/aislamiento & purificación , Humanos , Hipoglucemiantes/aislamiento & purificación , Hipoglucemiantes/toxicidad , Indígenas Norteamericanos , Medicina Tradicional , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Extractos Vegetales/aislamiento & purificación , Reacción en Cadena de la Polimerasa , Quebec , ARN Mensajero/metabolismo , Factores de TiempoRESUMEN
BACKGROUND: Patients with coronary artery disease (CAD) are at risk of accelerated cognitive decline, particularly those with major depression. Mechanisms for cognitive deficits associated with CAD, and the effects of depression, remain poorly understood. However, CAD is associated with inflammatory processes that have been linked to neurodegeneration, may contribute to cognitive decline, and are elevated in depression. Platelet-activating factors (PAFs) are emerging as key lipid mediators that may be central to those processes and highly relevant to cognitive decline in CAD. METHODS: This cross-sectional study investigated relationships between various PAFs and cognitive performance in 24 patients with CAD (age, 60.3 ± 9.4; 70.8% male). Analyses were repeated in a subgroup of 15 patients with CAD with major depression (DSM-IV). Cognitive performance was assessed using a standardized battery and summary z scores were calculated based on age, sex, and education norms. Global cognitive performance was the average of domain-specific z scores. Plasma PAF analyses were performed using electrospray ionization mass spectrometry (precursor ion scan). RESULTS: A greater abundance of PAF PC(O-18:0/2:0) was associated with poorer global cognitive performance in patients with CAD (r=-0.45, P=0.03). In the major depressed subgroup, PAF PC(O-18:0/2:0) (r=-0.59, P=0.02) as well as PC(O-16:0/2:0) (r=-0.52, P=0.04), and lyso-PAF PC(O-16:0/0:0) (r=-0.53, P=0.04) were associated with poorer global cognitive performance. A greater abundance of PAF PC(O-19:5/2:0) was associated with better global cognitive performance (r=0.55, P=0.03), suggesting a possible compensatory species. CONCLUSIONS: This study suggests that certain PAFs might be associated with global cognitive performance in patients with CAD, with stronger relationships observed in those with major depression. Confirmation of these preliminary findings is warranted.
Asunto(s)
Trastornos del Conocimiento/sangre , Trastornos del Conocimiento/etiología , Enfermedad de la Arteria Coronaria/complicaciones , Trastorno Depresivo Mayor/complicaciones , Factor de Activación Plaquetaria/metabolismo , Anciano , Cromatografía Líquida de Alta Presión , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Espectrometría de Masa por Ionización de Electrospray , Estadística como AsuntoRESUMEN
MOTIVATION: Establishing phospholipid identities in large lipidomic datasets is a labour-intensive process. Where genomics and proteomics capitalize on sequence-based signatures, glycerophospholipids lack easily definable molecular fingerprints. Carbon chain length, degree of unsaturation, linkage, and polar head group identity must be calculated from mass to charge (m/z) ratios under defined mass spectrometry (MS) conditions. Given increasing MS sensitivity, many m/z values are not represented in existing prediction engines. To address this need, Visualization and Phospholipid Identification is a web-based application that returns all theoretically possible phospholipids for any m/z value and MS condition. Visualization algorithms produce multiple chemical structure files for each species. Curated lipids detected by the Canadian Institutes of Health Research Training Program in Neurodegenerative Lipidomics are provided as high-resolution structures. AVAILABILITY: VaLID is available through the Canadian Institutes of Health Research Training Program in Neurodegenerative Lipidomics resources web site at https://www.med.uottawa.ca/lipidomics/resources.html. CONTACTS: lipawrd@uottawa.ca SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.