RESUMO
Isolation of multiple cell populations from limited starting material and with minimal influence on cell homeostasis and viability are common requirements in both basic and clinical research. Fluorescence-activated cell sorting (FACS) is the most commonly applied sorting methodology with the majority of instruments being based on high pressure and electrostatic deflection. A more recent technology is based on a mechanical valve, operating at low pressure. In the present work we compared the two technologies by parallel sorting of small amounts of peripheral blood and umbilical cord blood on a BD FACSAria™ III and Miltenyi MACSQuant® Tyto® instrument. Concurrent manually performed magnetic-based cell sorting served as reference. Sorting metrics, including purity and viability, were compared. Expression of the heat-shock protein HSPA1A immediately post sorting and the proliferation potential of sorted T-cells in vitro was assessed. In general, there was little to distinguish the two fluorescence-activated technologies with regard to sorting metrics and HSPA1A expression. Variation, however, with respect to recovery and viability, was much smaller among Tyto sorted samples. The proliferation potential of Tyto-sorted T-cells was significantly higher compared to Aria-sorted T-cells, indicating that T-cells of the Tyto instrument are less perturbed. In summary, cell types of blood origin including CD34+ cells could effectively be isolated from small input amounts with either fluorescence-activated technology with little immediate effect on viability. The mechanical valve-based sorting by the Tyto instrument; however, appeared to perturb the cells to a lesser extent as judged by their proliferation potential.
Assuntos
Sangue Fetal , Separação Celular/métodos , Citometria de Fluxo/métodos , Eletricidade EstáticaRESUMO
Aggregation of α-synuclein (αSN) is an important histological feature of Parkinson disease. Recent studies showed that the release of misfolded αSN from human and rodent neurons is relevant to the progression and spread of αSN pathology. Little is known, however, about the mechanisms responsible for clearance of extracellular αSN. This study found that human complement receptor (CR) 4 selectively bound fibrillar αSN, but not monomeric species. αSN is an abundant protein in the CNS, which potentially could overwhelm clearance of cytotoxic αSN species. The selectivity of CR4 toward binding fibrillar αSN consequently adds an important αSN receptor function for maintenance of brain homeostasis. Based on the recently solved structures of αSN fibrils and the known ligand preference of CR4, we hypothesize that the parallel monomer stacking in fibrillar αSN creates a known danger-associated molecular pattern of stretches of anionic side chains strongly bound by CR4. Conformational change in the receptor regulated tightly clearance of fibrillar αSN by human monocytes. The induced change coupled concomitantly with phagolysosome formation. Data mining of the brain transcriptome in Parkinson disease patients supported CR4 as an active αSN clearance mechanism in this disease. Our results associate an important part of the innate immune system, namely complement receptors, with the central molecular mechanisms of CNS protein aggregation in neurodegenerative disorders.
Assuntos
Integrina alfaXbeta2 , Macrófagos , Doença de Parkinson , Fagossomos , Agregação Patológica de Proteínas , alfa-Sinucleína , Humanos , Integrina alfaXbeta2/química , Integrina alfaXbeta2/genética , Integrina alfaXbeta2/imunologia , Macrófagos/imunologia , Macrófagos/patologia , Doença de Parkinson/genética , Doença de Parkinson/imunologia , Doença de Parkinson/patologia , Fagossomos/química , Fagossomos/genética , Fagossomos/imunologia , Fagossomos/patologia , Agregação Patológica de Proteínas/genética , Agregação Patológica de Proteínas/imunologia , Agregação Patológica de Proteínas/patologia , Estrutura Quaternária de Proteína , alfa-Sinucleína/química , alfa-Sinucleína/genética , alfa-Sinucleína/imunologiaRESUMO
The 15q13.3 deletion is associated with multiple neurodevelopmental disorders including epilepsy, schizophrenia, and autism. The Df(h15q13)/+ mouse model was recently generated that recapitulates several phenotypic features of the human 15q13.3 deletion syndrome (DS). However, the biological substrates underlying these phenotypes in Df(h15q13)/+ mice have not yet been fully characterized. RNA sequencing followed by real-time quantitative PCR, western blotting, liquid chromatography-mass spectrometry, and stereological analysis were employed to dissect the molecular, structural, and neurochemical phenotypes of the medial prefrontal cortex (mPFC) circuits in Df(h15q13)/+ mouse model. Transcriptomic profiling revealed enrichment for astrocyte-specific genes among differentially expressed genes, translated by a decrease in the number of glial fibrillary acidic protein positive cells in mPFC of Df(h15q13)/+ mice compared with wild-type mice. mPFC in Df(h15q13)/+ mice also showed a deficit of the inhibitory presynaptic marker GAD65, in addition to a reduction in dendritic arborization and spine density of pyramidal neurons from layers II/III. mPFC levels of GABA and glutamate neurotransmitters were not different between genotypes. Our results suggest that the 15q13.3 deletion modulates nonneuronal circuits in mPFC and confers molecular and morphometric alterations in the inhibitory and excitatory neurocircuits, respectively. These alterations potentially contribute to the phenotypes accompanied with the 15q13.3DS.
Assuntos
Astrócitos/patologia , Transtornos Cromossômicos/patologia , Transtornos Cromossômicos/fisiopatologia , Deficiência Intelectual/patologia , Deficiência Intelectual/fisiopatologia , Córtex Pré-Frontal/patologia , Córtex Pré-Frontal/fisiopatologia , Convulsões/patologia , Convulsões/fisiopatologia , Sinapses/patologia , Animais , Deleção Cromossômica , Cromossomos Humanos Par 15 , Modelos Animais de Doenças , Masculino , CamundongosRESUMO
Genetic and molecular studies have implicated the Bromodomain containing 1 (BRD1) gene in the pathogenesis of schizophrenia and bipolar disorder. Accordingly, mice heterozygous for a targeted deletion of Brd1 (Brd1+/- mice) show behavioral phenotypes with broad translational relevance to psychiatric disorders. BRD1 encodes a scaffold protein that affects the expression of many genes through modulation of histone acetylation. BRD1 target genes have been identified in cell lines; however the impact of reduced Brd1 levels on the brain proteome is largely unknown. In this study, we applied label-based quantitative mass spectrometry to profile the frontal cortex, hippocampus and striatum proteome and synaptosomal proteome of female Brd1+/- mice. We successfully quantified between 1537 and 2196 proteins and show widespread changes in protein abundancies and compartmentalization. By integrative analysis of human genetic data, we find that the differentially abundant proteins in frontal cortex and hippocampus are enriched for schizophrenia risk further linking the actions of BRD1 to psychiatric disorders. Affected proteins were further enriched for proteins involved in processes known to influence neuronal and dendritic spine morphology e.g. regulation of cytoskeleton dynamics and mitochondrial function. Directly prompted in these findings, we investigated dendritic spine morphology of pyramidal neurons in anterior cingulate cortex and found them significantly altered, including reduced size of small dendritic spines and decreased number of the mature mushroom type. Collectively, our study describes known as well as new mechanisms related to BRD1 dysfunction and its role in psychiatric disorders, and provides evidence for the molecular and cellular dysfunctions underlying altered neurosignalling and cognition in Brd1+/- mice.
Assuntos
Encéfalo/metabolismo , Encéfalo/patologia , Espinhas Dendríticas/patologia , Histona Acetiltransferases/genética , Esquizofrenia , Animais , Feminino , Camundongos , Proteoma , Esquizofrenia/genética , Esquizofrenia/metabolismo , Esquizofrenia/patologiaRESUMO
The blood-brain barrier consists of a tightly sealed monolayer of endothelial cells being vital in maintaining a stable intracerebral microenvironment. The barrier is receptive to leakage upon exposure to environmental factors, like hypoxia, and its disruption has been suggested as a constituent in the pathophysiology of both neurological and psychiatric disorders. The schizophrenia associated ZEB1 gene encodes a transcription factor susceptible to transcriptional control by a hypoxia induced factor, HIF1A, known to be implicated in blood-brain barrier dysfunction. However, whether ZEB1 is also implicated in maintaining blood-brain barrier integrity upon hypoxia is unknown. Here we assessed Hif1a, Zo1 and Zeb1 mRNA expression and ZO1 protein abundancy in a mimetic system of the in vivo blood-brain barrier comprising mouse brain endothelial cells subjected to the norm- and proven hypoxic conditions. Despite that, Hif1a mRNA expression was significantly increased, clearly indicating that the oxygen-deprived environment introduced a hypoxia response in the cells, we found no hypoxia-induced changes in neither ZO1 abundancy nor in the expression of Zo1 and Zeb1 mRNA. However, independent of hypoxia status, we found that Zeb1 and Zo1 mRNA expression is highly correlated. Further studies are warranted that investigate the implication of the ZEB1/ZO1 axis in blood-brain barrier maintenance under different physiological conditions.
Assuntos
Barreira Hematoencefálica/metabolismo , Microambiente Celular , Células Endoteliais/metabolismo , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismo , Animais , Hipóxia Celular , Linhagem Celular , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Camundongos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Regulação para Cima , Homeobox 1 de Ligação a E-box em Dedo de Zinco/genética , Proteína da Zônula de Oclusão-1/genética , Proteína da Zônula de Oclusão-1/metabolismoRESUMO
Breast cancer type 1 susceptibility protein (BRCA1) has a multitude of functions that contribute to genome integrity and tumor suppression. Its participation in the repair of DNA double-strand breaks (DSBs) during homologous recombination (HR) is well recognized, whereas its involvement in the second major DSB repair pathway, nonhomologous end-joining (NHEJ), remains controversial. Here we have studied the role of BRCA1 in the repair of DSBs in switch (S) regions during immunoglobulin class switch recombination, a physiological, deletion/recombination process that relies on the classical NHEJ machinery. A shift to the use of microhomology-based, alternative end-joining (A-EJ) and increased frequencies of intra-S region deletions as well as insertions of inverted S sequences were observed at the recombination junctions amplified from BRCA1-deficient human B cells. Furthermore, increased use of long microhomologies was found at recombination junctions derived from E3 ubiquitin-protein ligase RNF168-deficient, Fanconi anemia group J protein (FACJ, BRIP1)-deficient, or DNA endonuclease RBBP8 (CtIP)-compromised cells, whereas an increased frequency of S-region inversions was observed in breast cancer type 2 susceptibility protein (BRCA2)-deficient cells. Thus, BRCA1, together with its interaction partners, seems to play an important role in repairing DSBs generated during class switch recombination by promoting the classical NHEJ pathway. This may not only provide a general mechanism underlying BRCA1's function in maintaining genome stability and tumor suppression but may also point to a previously unrecognized role of BRCA1 in B-cell lymphomagenesis.
Assuntos
Linfócitos B/metabolismo , Proteína BRCA1/genética , Reparo do DNA , Switching de Imunoglobulina , Recombinação Genética , HumanosRESUMO
Schizophrenia is a debilitating brain disorder characterized by disturbances of emotion, perception and cognition. Cognitive impairments predict functional outcome in schizophrenia and are detectable even in the prodromal stage of the disorder. However, our understanding of the underlying neurobiology is limited and procognitive treatments remain elusive. We recently demonstrated that mice heterozygous for an inactivated allele of the schizophrenia-associated Brd1 gene (Brd1+/- mice) display behaviors reminiscent of schizophrenia, including impaired social cognition and long-term memory. Here, we further characterize performance of these mice by following the preclinical guidelines recommended by the 'Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS)' and 'Cognitive Neuroscience Treatment Research to Improve Cognition in Schizophrenia (CNTRICS)' initiatives to maximize translational value. Brd1+/- mice exhibit relational encoding deficits, compromised working and long term memory, as well as impaired executive cognitive functioning with cognitive behaviors relying on medial prefrontal cortex being particularly affected. Akin to patients with schizophrenia, the cognitive deficits displayed by Brd1+/- mice are not global, but selective. Our results underline the value of Brd1+/- mice as a promising tool for studying the neurobiology of cognitive deficits in schizophrenia.
Assuntos
Transtornos Cognitivos/genética , Cognição/fisiologia , Função Executiva/fisiologia , Histona Acetiltransferases/genética , Esquizofrenia/genética , Alelos , Animais , Comportamento Animal/fisiologia , Transtornos Cognitivos/fisiopatologia , Modelos Animais de Doenças , Heterozigoto , Masculino , Memória de Longo Prazo/fisiologia , Memória de Curto Prazo/fisiologia , Camundongos , Camundongos Knockout , Córtex Pré-Frontal/fisiopatologia , Esquizofrenia/fisiopatologiaRESUMO
BACKGROUND: Massively parallel cDNA sequencing (RNA-seq) experiments are gradually superseding microarrays in quantitative gene expression profiling. However, many biologists are uncertain about the choice of differentially expressed gene (DEG) analysis methods and the validity of cost-saving sample pooling strategies for their RNA-seq experiments. Hence, we performed experimental validation of DEGs identified by Cuffdiff2, edgeR, DESeq2 and Two-stage Poisson Model (TSPM) in a RNA-seq experiment involving mice amygdalae micro-punches, using high-throughput qPCR on independent biological replicate samples. Moreover, we sequenced RNA-pools and compared their results with sequencing corresponding individual RNA samples. RESULTS: False-positivity rate of Cuffdiff2 and false-negativity rates of DESeq2 and TSPM were high. Among the four investigated DEG analysis methods, sensitivity and specificity of edgeR was relatively high. We documented the pooling bias and that the DEGs identified in pooled samples suffered low positive predictive values. CONCLUSIONS: Our results highlighted the need for combined use of more sensitive DEG analysis methods and high-throughput validation of identified DEGs in future RNA-seq experiments. They indicated limited utility of sample pooling strategies for RNA-seq in similar setups and supported increasing the number of biological replicate samples.
Assuntos
DNA Complementar/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Análise de Sequência de RNA , Animais , Camundongos , SoftwareRESUMO
OBJECTIVES: Breakpoints of chromosomal abnormalities facilitate identification of novel candidate genes for psychiatric disorders. Genome-wide significant evidence supports the linkage between chromosome 17q25.3 and bipolar disorder (BD). Co-segregation of translocation t(9;17)(q33.2;q25.3) with psychiatric disorders has been reported. We aimed to narrow down these chromosomal breakpoint regions and to investigate the associations between single nucleotide polymorphisms within these regions and BD as well as schizophrenia (SZ) in large genome-wide association study samples. METHODS: We cross-linked Danish psychiatric and cytogenetic case registers to identify an individual with both t(9;17)(q33.2;q25.3) and BD. Fluorescent in situ hybridization was employed to map the chromosomal breakpoint regions of this proband. We accessed the Psychiatric Genomics Consortium BD (n = 16,731) and SZ (n = 21,856) data. Genetic associations between these disorders and single nucleotide polymorphisms within these breakpoint regions were analysed by BioQ, FORGE, and RegulomeDB programmes. RESULTS: Four protein-coding genes [coding for (endonuclease V (ENDOV), neuronal pentraxin I (NPTX1), ring finger protein 213 (RNF213), and regulatory-associated protein of mammalian target of rapamycin (mTOR) (RPTOR)] were found to be located within the 17q25.3 breakpoint region. NPTX1 was significantly associated with BD (p = 0.004), while ENDOV was significantly associated with SZ (p = 0.0075) after Bonferroni correction. CONCLUSIONS: Prior linkage evidence and our findings suggest NPTX1 as a novel candidate gene for BD.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Transtorno Bipolar/genética , Proteína C-Reativa/genética , Desoxirribonuclease (Dímero de Pirimidina)/genética , Proteínas do Tecido Nervoso/genética , Esquizofrenia/genética , Ubiquitina-Proteína Ligases/genética , Adenosina Trifosfatases , Cromossomos Humanos Par 17/genética , Cromossomos Humanos Par 9/genética , Família , Ligação Genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Hibridização in Situ Fluorescente , Polimorfismo de Nucleotídeo Único , Proteína Regulatória Associada a mTOR , Translocação Genética/genéticaRESUMO
Seckel syndrome is a recessively inherited dwarfism disorder characterized by microcephaly and a unique head profile. Genetically, it constitutes a heterogeneous condition, with several loci mapped (SCKL1-5) but only three disease genes identified: the ATR, CENPJ, and CEP152 genes that control cellular responses to DNA damage. We previously mapped a Seckel syndrome locus to chromosome 18p11.31-q11.2 (SCKL2). Here, we report two mutations in the CtIP (RBBP8) gene within this locus that result in expression of C-terminally truncated forms of CtIP. We propose that these mutations are the molecular cause of the disease observed in the previously described SCKL2 family and in an additional unrelated family diagnosed with a similar form of congenital microcephaly termed Jawad syndrome. While an exonic frameshift mutation was found in the Jawad family, the SCKL2 family carries a splicing mutation that yields a dominant-negative form of CtIP. Further characterization of cell lines derived from the SCKL2 family revealed defective DNA damage induced formation of single-stranded DNA, a critical co-factor for ATR activation. Accordingly, SCKL2 cells present a lowered apoptopic threshold and hypersensitivity to DNA damage. Notably, over-expression of a comparable truncated CtIP variant in non-Seckel cells recapitulates SCKL2 cellular phenotypes in a dose-dependent manner. This work thus identifies CtIP as a disease gene for Seckel and Jawad syndromes and defines a new type of genetic disease mechanism in which a dominant negative mutation yields a recessively inherited disorder.
Assuntos
Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Proteínas de Ciclo Celular/metabolismo , Nanismo/genética , Microcefalia/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Anormalidades Múltiplas/genética , Sequência de Aminoácidos , Proteínas Mutadas de Ataxia Telangiectasia , Sequência de Bases , Proteínas de Ciclo Celular/genética , Células Cultivadas , Dano ao DNA , DNA de Cadeia Simples , Nanismo/patologia , Endodesoxirribonucleases , Mutação da Fase de Leitura , Genes Dominantes , Genes Recessivos , Instabilidade Genômica , Humanos , Microcefalia/patologia , Dados de Sequência Molecular , Proteínas Serina-Treonina Quinases/genética , Splicing de RNA/genética , Transdução de SinaisRESUMO
Sorting receptor SORCS2 is a stress-response factor protecting neurons from acute insults, such as during epilepsy. SORCS2 is also expressed in the pancreas, yet its action in this tissue remains unknown. Combining metabolic studies in SORCS2-deficient mice with ex vivo functional analyses and single-cell transcriptomics of pancreatic tissues, we identified a role for SORCS2 in protective stress response in pancreatic islets, essential to sustain insulin release. We show that SORCS2 is predominantly expressed in islet alpha cells. Loss of expression coincides with inability of these cells to produce osteopontin, a secreted factor that facilitates insulin release from stressed beta cells. In line with diminished osteopontin levels, beta cells in SORCS2-deficient islets show gene expression patterns indicative of aggravated cell stress, and exhibit defects in insulin granule maturation and a blunted glucose response. These findings corroborate a function for SORCS2 in protective stress response that extends to metabolism.
RESUMO
Current differentiation protocols for generating mesencephalic dopaminergic (mesDA) neurons from human pluripotent stem cells result in grafts containing only a small proportion of mesDA neurons when transplanted in vivo. In this study, we develop lineage-restricted undifferentiated stem cells (LR-USCs) from pluripotent stem cells, which enhances their potential for differentiating into caudal midbrain floor plate progenitors and mesDA neurons. Using a ventral midbrain protocol, 69% of LR-USCs become bona fide caudal midbrain floor plate progenitors, compared to only 25% of human embryonic stem cells (hESCs). Importantly, LR-USCs generate significantly more mesDA neurons under midbrain and hindbrain conditions in vitro and in vivo. We demonstrate that midbrain-patterned LR-USC progenitors transplanted into 6-hydroxydopamine-lesioned rats restore function in a clinically relevant non-pharmacological behavioral test, whereas midbrain-patterned hESC-derived progenitors do not. This strategy demonstrates how lineage restriction can prevent the development of undesirable lineages and enhance the conditions necessary for mesDA neuron generation.
Assuntos
Neurônios Dopaminérgicos , Células-Tronco Pluripotentes , Humanos , Ratos , Animais , Neurônios Dopaminérgicos/metabolismo , Fatores de Transcrição/metabolismo , Diferenciação Celular/fisiologia , Mesencéfalo , Células-Tronco Pluripotentes/metabolismoRESUMO
Motor neuron (MN) development and nerve regeneration requires orchestrated action of a vast number of molecules. Here, we identify SorCS2 as a progranulin (PGRN) receptor that is required for MN diversification and axon outgrowth in zebrafish and mice. In zebrafish, SorCS2 knockdown also affects neuromuscular junction morphology and fish motility. In mice, SorCS2 and PGRN are co-expressed by newborn MNs from embryonic day 9.5 until adulthood. Using cell-fate tracing and nerve segmentation, we find that SorCS2 deficiency perturbs cell-fate decisions of brachial MNs accompanied by innervation deficits of posterior nerves. Additionally, adult SorCS2 knockout mice display slower motor nerve regeneration. Interestingly, primitive macrophages express high levels of PGRN, and their interaction with SorCS2-positive motor axon is required during axon pathfinding. We further show that SorCS2 binds PGRN to control its secretion, signaling, and conversion into granulins. We propose that PGRN-SorCS2 signaling controls MN development and regeneration in vertebrates.
Assuntos
Peptídeos e Proteínas de Sinalização Intercelular , Peixe-Zebra , Camundongos , Animais , Progranulinas , Peixe-Zebra/metabolismo , Neurônios Motores/metabolismo , Granulinas , Camundongos Knockout , Proteínas do Tecido Nervoso/metabolismo , Receptores de Superfície Celular/metabolismoRESUMO
Depression is a common psychiatric disorder and a leading cause of disability worldwide. Here we conducted a genome-wide association study meta-analysis of six datasets, including >1.3 million individuals (371,184 with depression) and identified 243 risk loci. Overall, 64 loci were new, including genes encoding glutamate and GABA receptors, which are targets for antidepressant drugs. Intersection with functional genomics data prioritized likely causal genes and revealed new enrichment of prenatal GABAergic neurons, astrocytes and oligodendrocyte lineages. We found depression to be highly polygenic, with ~11,700 variants explaining 90% of the single-nucleotide polymorphism heritability, estimating that >95% of risk variants for other psychiatric disorders (anxiety, schizophrenia, bipolar disorder and attention deficit hyperactivity disorder) were influencing depression risk when both concordant and discordant variants were considered, and nearly all depression risk variants influenced educational attainment. Additionally, depression genetic risk was associated with impaired complex cognition domains. We dissected the genetic and clinical heterogeneity, revealing distinct polygenic architectures across subgroups of depression and demonstrating significantly increased absolute risks for recurrence and psychiatric comorbidity among cases of depression with the highest polygenic burden, with considerable sex differences. The risks were up to 5- and 32-fold higher than cases with the lowest polygenic burden and the background population, respectively. These results deepen the understanding of the biology underlying depression, its disease progression and inform precision medicine approaches to treatment.
Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Transtorno Bipolar , Esquizofrenia , Masculino , Feminino , Humanos , Estudo de Associação Genômica Ampla , Depressão , Transtorno Bipolar/epidemiologia , Transtorno Bipolar/genética , Esquizofrenia/epidemiologia , Esquizofrenia/genética , Transtorno do Deficit de Atenção com Hiperatividade/epidemiologia , Transtorno do Deficit de Atenção com Hiperatividade/genética , Polimorfismo de Nucleotídeo Único/genética , Predisposição Genética para DoençaRESUMO
Bipolar disorder is a debilitating psychiatric condition that is shaped in a concerted interplay between hereditary and triggering risk factors. Profound depression and mania define the disorder, but high clinical heterogeneity among patients complicates diagnosis as well as pharmacological intervention. Identification of peripheral biomarkers that capture the genomic response to the exposome may thus progress the development of personalized treatment. MicroRNAs (miRNAs) play a prominent role in of post-transcriptional gene regulation in the context of brain development and mental health. They are coordinately modulated by multifarious effectors, and alteration in their expression profile has been reported in a variety of psychiatric conditions. Intriguingly, miRNAs can be released from CNS cells and enter circulatory bio-fluids where they remain remarkably stable. Hence, peripheral circulatory miRNAs may act as bio-indicators for the combination of genetic risk, environmental exposure, and/or treatment response. Here we provide a comprehensive literature search and data mining approach that summarize current experimental evidence supporting the applicability of miRNAs for patient stratification in bipolar disorder.
Assuntos
Transtorno Bipolar , MicroRNA Circulante , MicroRNAs , Biomarcadores , Transtorno Bipolar/diagnóstico , Transtorno Bipolar/genética , MicroRNA Circulante/genética , Mineração de Dados , Humanos , MicroRNAs/genética , MicroRNAs/metabolismoRESUMO
Bromodomain containing 1 (BRD1) encodes an epigenetic regulator that controls the expression of genetic networks linked to mental illness. BRD1 is essential for normal brain development and its role in psychopathology has been demonstrated in genetic and preclinical studies. However, the neurobiology that bridges its molecular and neuropathological effects remains poorly explored. Here, using publicly available datasets, we find that BRD1 targets nuclear genes encoding mitochondrial proteins in cell lines and that modulation of BRD1 expression, irrespective of whether it is downregulation or upregulation of one or the other existing BRD1 isoforms (BRD1-L and BRD1-S), leads to distinct shifts in the expression profile of these genes. We further show that the expression of nuclear genes encoding mitochondrial proteins is negatively correlated with the expression of BRD1 mRNA during human brain development. In accordance, we identify the key gate-keeper of mitochondrial metabolism, Peroxisome proliferator-activated receptor (PPAR) among BRD1's co-transcription factors and provide evidence that BRD1 acts as a co-repressor of PPAR-mediated transcription. Lastly, when using quantitative PCR, mitochondria-targeted fluorescent probes, and the Seahorse XFe96 Analyzer, we demonstrate that modulation of BRD1 expression in cell lines alters mitochondrial physiology (mtDNA content and mitochondrial mass), metabolism (reducing power), and bioenergetics (among others, basal, maximal, and spare respiration) in an expression level- and isoform-dependent manner. Collectively, our data suggest that BRD1 is a transcriptional regulator of nuclear-encoded mitochondrial proteins and that disruption of BRD1's genomic actions alters mitochondrial functions. This may be the mechanism underlying the cellular and atrophic changes of neurons previously associated with BRD1 deficiency and suggests that mitochondrial dysfunction may be a possible link between genetic variation in BRD1 and psychopathology in humans.
Assuntos
Histona Acetiltransferases , Esquizofrenia , Metabolismo Energético , Histona Acetiltransferases/fisiologia , Humanos , Mitocôndrias/metabolismo , Proteínas Mitocondriais , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , Isoformas de Proteínas/metabolismo , Esquizofrenia/genéticaRESUMO
BACKGROUND: Treatment of patients with perioxisome proliferator-activated receptor-γ full agonists are associated with weight gain, heart failure, peripheral oedema, and bone loss. However, the safety of partial perioxisome proliferator-activated receptor-γ agonists has not been established in a clinical trial. The BALaglitazone glucose Lowering Efficacy Trial aimed to establish the glucose-lowering effects and safety parameters of the perioxisome proliferator-activated receptor-γ partial agonist balaglitazone in diabetic patients on stable insulin therapy. METHODS: Four hundred and nine subjects from three countries with type 2 diabetes on stable insulin therapy were randomized to 26 weeks of double-blind treatment with once daily doses of 10 or 20 mg balaglitazone, 45 mg pioglitazone, or matching placebo (n ≥ 99 in each group). The primary endpoint was the efficacy of balaglitazone 10 and 20 mg versus placebo on the absolute change in haemoglobin A(1c) . Secondary endpoints included levels of fasting serum glucose, and changes in body composition and bone mineral density as measured by dual energy X-ray absorptiometry, in comparison to pioglitazone 45 mg. This study is registered with Clinicaltrials.gov identifier: NCT00515632. RESULTS: In the 10- and 20-mg balaglitazone groups, and in the 45-mg pioglitazone group, significant reductions in haemoglobin A(1c) levels were observed (−0.99, −1.11, and −1.22%, respectively; p < 0.0001) versus placebo. Fasting serum glucose was similarly reduced in all treatment arms. Dual energy X-ray absorptiometry analyses showed that, while balaglitazone at 10 mg caused weight gain and fluid retention compared to placebo, the magnitude of these effects was significantly smaller than that of pioglitazone 45 mg and balaglitazone 20mg. Balaglitazone at either dose did not appear to reduce bone mineral density, while Pioglitazone showed a trend towards a reduction. CONCLUSION: Patients treated with balaglitazone at 10 mg and 20 mg and pioglitazone at 45 mg showed clinically meaningful improvements in glucose levels and HbA(1c) . With the 10 mg dose, the benefits (glucose & HgA(1c) lowering) and untoward effects (fluid and fat accumulation) were less, results that encourage further studies of this drug candidate.
Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , PPAR gama/antagonistas & inibidores , Quinazolinas/uso terapêutico , Tiazolidinedionas/uso terapêutico , Idoso , Glicemia/análise , Composição Corporal/efeitos dos fármacos , Densidade Óssea/efeitos dos fármacos , Diabetes Mellitus Tipo 2/sangue , Relação Dose-Resposta a Droga , Método Duplo-Cego , Quimioterapia Combinada/efeitos adversos , Feminino , Hemoglobinas Glicadas/análise , Humanos , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/efeitos adversos , Masculino , Pessoa de Meia-Idade , Pioglitazona , Quinazolinas/administração & dosagem , Quinazolinas/efeitos adversos , Tiazolidinedionas/administração & dosagem , Tiazolidinedionas/efeitos adversos , Equilíbrio Hidroeletrolítico/efeitos dos fármacos , Aumento de Peso/efeitos dos fármacosRESUMO
Visceral adipose tissue shows remarkable plasticity, constantly replacing mature adipocytes from an inherent pool of adipocyte precursors. The number of precursors is set in the juvenile organism and remains constant in adult life. Which signals drive precursor pool expansion in juveniles and why they operate in visceral but not in subcutaneous white adipose tissue (WAT) are unclear. Using mouse models, we identified the insulin-sensitizing receptor SORLA as a molecular factor explaining the distinct proliferative capacity of visceral WAT. High levels of SORLA activity in precursors of juvenile visceral WAT prime these cells for nutritional stimuli provided through insulin, promoting mitotic expansion of the visceral precursor cell pool in overfed juvenile mice. SORLA activity is low in subcutaneous precursors, blunting their response to insulin and preventing diet-induced proliferation of this cell type. Our findings provide a molecular explanation for the unique proliferative properties of juvenile visceral WAT, and for the genetic association of SORLA with visceral obesity in humans.
Assuntos
Adipócitos/citologia , Insulina/farmacologia , Gordura Intra-Abdominal/metabolismo , Proteínas Relacionadas a Receptor de LDL/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Receptores de LDL/metabolismo , Células-Tronco/citologia , Células-Tronco/metabolismo , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Tecido Adiposo Branco/efeitos dos fármacos , Tecido Adiposo Branco/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Índice de Massa Corporal , Proliferação de Células/efeitos dos fármacos , Feminino , Humanos , Masculino , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Mitógenos/farmacologia , Células-Tronco/efeitos dos fármacos , Gordura Subcutânea/efeitos dos fármacos , Gordura Subcutânea/metabolismo , Adulto JovemRESUMO
Neurons produced by reprogramming of other cell types are used to study cellular mechanisms of age-related neurodegenerative diseases. To model Alzheimer's disease and other tauopathies, it is essential that alternative splicing of the MAPT transcript in these neurons produces the relevant tau isoforms. Human neurons derived from induced pluripotent stem cells, however, express tau isoform compositions characteristic of foetal neurons rather than of adult neurons unless cultured in vitro for extended time periods. In this study, we characterised the dynamics of the MAPT and APP alternative splicing during a developmental time-course of porcine and murine cerebral cortices. We found age-dependent and species-specific isoform composition of MAPT, including 3R and 4R isoforms in the porcine adult brain similar to that of the adult human brain. We converted adult and embryonic fibroblasts directly into induced neurons and found similar developmental patterns of isoform composition, notably, the 3R and 4R isoforms relevant to the pathogenesis of Alzheimer's disease. Also, we observed cell-type-specific isoform expression of APP transcripts during the conversion. The approach was further used to generate induced neurons from transgenic pigs carrying Alzheimer's disease-causing mutations. We show that such neurons authentically model the first crucial steps in AD pathogenesis.
Assuntos
Envelhecimento/metabolismo , Precursor de Proteína beta-Amiloide/metabolismo , Encéfalo/metabolismo , Degeneração Neural/metabolismo , Neurônios/metabolismo , Proteínas tau/metabolismo , Processamento Alternativo , Animais , Animais Geneticamente Modificados , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Doenças Neurodegenerativas/metabolismo , SuínosRESUMO
AIMS: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) binds to angiotensin converting enzyme 2 (ACE2) enabling entrance of the virus into cells and causing the infection termed coronavirus disease of 2019 (COVID-19). Here, we investigate associations between plasma ACE2 and outcome of COVID-19. METHODS AND RESULTS: This analysis used data from a large longitudinal study of 306 COVID-19 positive patients and 78 COVID-19 negative patients (MGH Emergency Department COVID-19 Cohort). Comprehensive clinical data were collected on this cohort, including 28-day outcomes. The samples were run on the Olink® Explore 1536 platform which includes measurement of the ACE2 protein. High admission plasma ACE2 in COVID-19 patients was associated with increased maximal illness severity within 28 days with OR = 1.8, 95%-CI: 1.4-2.3 (P < 0.0001). Plasma ACE2 was significantly higher in COVID-19 patients with hypertension compared with patients without hypertension (P = 0.0045). Circulating ACE2 was also significantly higher in COVID-19 patients with pre-existing heart conditions and kidney disease compared with patients without these pre-existing conditions (P = 0.0363 and P = 0.0303, respectively). CONCLUSION: This study suggests that measuring plasma ACE2 is potentially valuable in predicting COVID-19 outcomes. Further, ACE2 could be a link between COVID-19 illness severity and its established risk factors hypertension, pre-existing heart disease and pre-existing kidney disease.