RESUMO
BACKGROUND AND AIMS: Alcohol-associated hepatitis (AH) is a clinically severe, acute disease that afflicts only a fraction of patients with alcohol use disorder (AUD). Genomic studies of alcohol-associated cirrhosis (AC) have identified several genes of large effect, but the genetic and environmental factors that lead to AH and AC, and their degree of genetic overlap, remain largely unknown. This study aims to identify genes and genetic variation that contribute to the development of AH. APPROACH AND RESULTS: Exome-sequencing of patients with AH (N=784) and heavy drinking controls (N=951) identified exome-wide significant association for AH at PNPLA3, as previously observed for AC in GWAS, although with a much lower effect-size. SNPs of large effect-size at ICOSLG (Chr 21) and TOX4/RAB2B (Chr 14), were also exome-wide significant. ICOSLG encodes a co-stimulatory signal for T-cell proliferation and cytokine secretion and induces B-cell proliferation and differentiation. TOX4 was previously implicated in diabetes and immune system function. Other genes previously implicated in AC did not strongly contribute to AH, and the only prominently implicated (but not exome wide significant) gene overlapping with AUD was ADH1B. Polygenic signals for AH were observed in both common and rare variant analysis and identified genes with roles associated with inflammation. CONCLUSIONS: This study has identified two new genes of high effect size with a previously unknown contribution to ALD, and highlights both the overlap in etiology between liver diseases, and the unique origins of AH.
RESUMO
Alcohol withdrawal is a clinically important consequence and potential driver of Alcohol Use Disorder. However, susceptibility to withdrawal symptoms, ranging from craving and anxiety to seizures and delirium, varies greatly. Selectively bred Withdrawal Seizure-Prone (WSP) and Seizure-Resistant (WSR) mice are an animal model of differential susceptibility to withdrawal and phenotypes with which withdrawal severity correlates. To identify innate drivers of alcohol withdrawal severity, we performed a multi-omic study of the WSP and WSR lines and F2 mice derived from them, using genomic, genetic, and transcriptomic analyses. Genes implicated in seizures and epilepsy were over-represented among those that segregated between WSP and WSR mice and that displayed differential expression in F2 mice high and low in withdrawal. Quantitative trait locus (QTL) analysis of ethanol withdrawal convulsions identified several genome-wide significant loci and pointed to genes that modulate potassium channel function and neural excitability. Perturbations of expression of genes involved in synaptic transmission, including GABAergic and glutamatergic genes, were prominent in prefrontal cortex transcriptome. Expression QTL (eQTL) analysis fine mapped genes within the peak ethanol withdrawal QTL regions. Genetic association analysis in human subjects provided converging evidence for the involvement of those genes in severity of alcohol withdrawal and dependence. Our results reveal a polygenic network and neural signaling pathways contributing to ethanol withdrawal seizures and related phenotypes that overlap with genes modulating epilepsy and neuronal excitability.
Assuntos
Alcoolismo , Epilepsia , Síndrome de Abstinência a Substâncias , Camundongos , Humanos , Animais , Síndrome de Abstinência a Substâncias/genética , Alcoolismo/genética , Convulsões/genética , EtanolRESUMO
Artificially selected model organisms can reveal hidden features of the genetic architecture of the complex disorders that they model. Addictions are disease phenotypes caused by different intermediate phenotypes and pathways and thereby are potentially highly polygenic. High responder (bHR) and low responder (bLR) rat lines have been selectively bred (b) for exploratory locomotion (EL), a behavioral phenotype correlated with novelty-seeking, impulsive response to reward, and vulnerability to addiction, and is inversely correlated with spontaneous anxiety and depression-like behaviors. The rapid response to selection indicates loci of large effect for EL. Using exome sequencing of HR and LR rats, we identified alleles in gene-coding regions that segregate between the two lines. Quantitative trait locus (QTL) analysis in F2 rats derived from a bHR × bLR intercross confirmed that these regions harbored genes affecting EL. The combined effects of the seven genome-wide significant QTLs accounted for approximately one-third of the total variance in EL, and two-thirds of the variance attributable to genetic factors, consistent with an oligogenic architecture of EL estimated both from the phenotypic distribution of F2 animals and rapid response to selection. Genetic association in humans linked APBA2, the ortholog of the gene at the center of the strongest QTL, with substance use disorders and related behavioral phenotypes. Our finding is also convergent with molecular and animal behavioral studies implicating Apba2 in locomotion. These results provide multilevel evidence for genes/loci influencing EL. They shed light on the genetic architecture of oligogenicity in animals artificially selected for a phenotype modeling a more complex disorder in humans.
Assuntos
Comportamento Aditivo/genética , Caderinas/genética , Comportamento Exploratório/fisiologia , Locomoção/genética , Proteínas do Tecido Nervoso/genética , Transtornos Relacionados ao Uso de Substâncias/genética , Animais , Comportamento Aditivo/fisiopatologia , Comportamento Animal/fisiologia , Proteínas de Transporte/genética , Estudos de Casos e Controles , Modelos Animais de Doenças , Feminino , Finlândia , Predisposição Genética para Doença , Técnicas de Genotipagem , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Ratos , Recompensa , Sequenciamento do ExomaRESUMO
Adaptations to stress can occur through epigenetic processes and may be a conduit for informing offspring of environmental challenge. We employed ChIP-sequencing for H3K4me3 to examine effects of early maternal deprivation (peer-rearing, PR) in archived rhesus macaque hippocampal samples (male, n = 13). Focusing on genes with roles in stress response and behavior, we assessed the effects of rearing on H3K4me3 binding by ANOVA. We found decreased H3K4me3 binding at genes critical to behavioral stress response, the most robust being the oxytocin receptor gene OXTR, for which we observed a corresponding decrease in RNA expression. Based on this finding, we performed behavioral analyses to determine whether a gain-of-function nonsynonymous OXTR SNP interacted with early stress to influence relevant behavioral stress reactivity phenotypes (n = 194), revealing that this SNP partially rescued the PR phenotype. PR infants exhibited higher levels of separation anxiety and arousal in response to social separation, but infants carrying the alternative OXTR allele did not exhibit as great a separation response. These data indicate that the oxytocin system is involved in social-separation response and suggest that epigenetic down-modulation of OXTR could contribute to behavioral differences observed in PR animals. Epigenetic changes at OXTR may represent predictive adaptive responses that could impart readiness to respond to environmental challenge or maintain proximity to a caregiver but also contribute to behavioral pathology. Our data also demonstrate that OXTR polymorphism can permit animals to partially overcome the detrimental effects of early maternal deprivation, which could have translational implications for human psychiatric disorders.
Assuntos
Epigênese Genética/genética , Macaca mulatta/genética , Receptores de Ocitocina/genética , Adaptação Psicológica/fisiologia , Alelos , Animais , Ansiedade de Separação/genética , Feminino , Hipocampo/metabolismo , Histonas/genética , Masculino , Privação Materna , Ocitocina/genética , Polimorfismo de Nucleotídeo Único/genética , Estresse Fisiológico/genéticaRESUMO
Earlier initiation of smoking correlates with higher risk of nicotine dependence, mental health problems, and cognitive impairments. Additionally, exposure to nicotine and/or tobacco smoke during critical developmental periods is associated with lasting epigenetic modifications and altered gene expression. This study examined whether adolescent nicotine exposure alters adult hippocampus-dependent learning, involving persistent changes in hippocampal DNA methylation and if choline, a dietary methyl donor, would reverse and mitigate these alterations. Mice were chronically treated with nicotine (12.6â¯mg/kg/day) starting at post-natal day 23 (pre-adolescent), p38 (late adolescent), or p54 (adult) for 12â¯days followed by a 30-day period during which they consumed either standard chow or chow supplemented with choline (9â¯g/kg). Mice then were tested for fear-conditioning and dorsal hippocampi were dissected for whole genome methylation and selected gene expression analyses. Nicotine exposure starting at p21 or p38, but not p54, disrupted adult hippocampus-dependent fear conditioning. Choline supplementation ameliorated these deficits. 462 genes in adult dorsal hippocampus from mice exposed to nicotine as adolescents showed altered promoter methylation that was reversed by choline supplementation. Gene network analysis revealed that chromatin remodeling genes were the most enriched category whose methylation was altered by nicotine and reversed by choline dietary supplementation. Two key chromatin remodeling genes, Smarca2 and Bahcc1, exhibited inversely correlated changes in methylation and expression due to nicotine exposure; this was reversed by choline. Our findings support a role for epigenetic modification of hippocampal chromatin remodeling genes in long-term learning deficits induced by adolescent nicotine and their amelioration by dietary choline supplementation.
Assuntos
Colina/administração & dosagem , Montagem e Desmontagem da Cromatina/efeitos dos fármacos , Condicionamento Clássico/efeitos dos fármacos , Epigênese Genética/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Nicotina/administração & dosagem , Fatores Etários , Animais , Fumar Cigarros/genética , Fumar Cigarros/psicologia , Condicionamento Clássico/fisiologia , Metilação de DNA , Medo , Hipocampo/metabolismo , Masculino , Camundongos Endogâmicos C57BLRESUMO
Recent studies have suggested an association between alcoholism and DNA methylation, a mechanism that can mediate long-lasting changes in gene transcription. Here, we examined the contribution of DNA methylation to the long-term behavioral and molecular changes induced by a history of alcohol dependence. In search of mechanisms underlying persistent rather than acute dependence-induced neuroadaptations, we studied the role of DNA methylation regulating medial prefrontal cortex (mPFC) gene expression and alcohol-related behaviors in rats 3 weeks into abstinence following alcohol dependence. Postdependent rats showed escalated alcohol intake, which was associated with increased DNA methylation as well as decreased expression of genes encoding synaptic proteins involved in neurotransmitter release in the mPFC. Infusion of the DNA methyltransferase inhibitor RG108 prevented both escalation of alcohol consumption and dependence-induced downregulation of 4 of the 7 transcripts modified in postdependent rats. Specifically, RG108 treatment directly reversed both downregulation of synaptotagmin 2 (Syt2) gene expression and hypermethylation on CpG#5 of its first exon. Lentiviral inhibition of Syt2 expression in the mPFC increased aversion-resistant alcohol drinking, supporting a mechanistic role of Syt2 in compulsive-like behavior. Our findings identified a functional role of DNA methylation in alcohol dependence-like behavioral phenotypes and a candidate gene network that may mediate its effects. Together, these data provide novel evidence for DNA methyltransferases as potential therapeutic targets in alcoholism.
Assuntos
Alcoolismo/patologia , Alcoolismo/fisiopatologia , Metilação de DNA/fisiologia , Plasticidade Neuronal/fisiologia , Córtex Pré-Frontal/metabolismo , Córtex Pré-Frontal/patologia , Animais , Comportamento de Escolha , Condicionamento Operante , Metilação de DNA/efeitos dos fármacos , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacologia , Etanol/administração & dosagem , Perfilação da Expressão Gênica , Masculino , Metiltransferases/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Ftalimidas/farmacologia , Ratos , Ratos Wistar , Autoadministração , Estatísticas não Paramétricas , Sinaptotagmina II/genética , Sinaptotagmina II/metabolismo , Transdução Genética , Triptofano/análogos & derivados , Triptofano/farmacologiaRESUMO
BACKGROUND: Genome-wide surveys have detected cis-acting quantitative trait loci altering levels of RNA transcripts (RNA-eQTLs) by associating SNV alleles to transcript levels. However, the sensitivity and specificity of detection of cis- expression quantitative trait loci (eQTLs) by genetic approaches, reliant as it is on measurements of transcript levels in recombinant inbred strains or offspring from arranged crosses, is unknown, as is their relationship to QTL's for complex phenotypes. RESULTS: We used transcriptome-wide differential allele expression (DAE) to detect cis-eQTLs in forebrain and kidney from reciprocal crosses between three mouse inbred strains, 129S1/SvlmJ, DBA/2J, and CAST/EiJ and C57BL/6 J. Two of these crosses were previously characterized for cis-eQTLs and QTLs for various complex phenotypes by genetic analysis of recombinant inbred (RI) strains. 5.4 %, 1.9 % and 1.5 % of genes assayed in forebrain of B6/129SF1, B6/DBAF1, and B6/CASTF1 mice, respectively, showed differential allelic expression, indicative of cis-acting alleles at these genes. Moreover, the majority of DAE QTLs were observed to be tissue-specific with only a small fraction showing cis-effects in both tissues. Comparing DAE QTLs in F1 mice to cis-eQTLs previously mapped in RI strains we observed that many of the cis-eQTLs were not confirmed by DAE. Additionally several novel DAE-QTLs not identified as cis-eQTLs were identified suggesting that there are differences in sensitivity and specificity for QTL detection between the two methodologies. Strain specific DAE QTLs in B6/DBAF1 mice were located in excess at candidate genes for alcohol use disorders, seizures, and angiogenesis previously implicated by genetic linkage in C57BL/6J × DBA/2JF2 mice or BXD RI strains. CONCLUSIONS: Via a survey for differential allele expression in F1 mice, a substantial proportion of genes were found to have alleles altering expression in cis-acting fashion. Comparing forebrain and kidney, many or most of these alleles were tissue-specific in action. The identification of strain specific DAE QTLs, can assist in assessment of candidate genes located within the large intervals associated with trait QTLs.
Assuntos
Alelos , Padrões de Herança , Locos de Características Quantitativas , Característica Quantitativa Herdável , Transcriptoma , Alcoolismo/genética , Alcoolismo/patologia , Animais , Cruzamentos Genéticos , Feminino , Regulação da Expressão Gênica , Genótipo , Rim/metabolismo , Rim/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Endogâmicos , Neovascularização Patológica/genética , Neovascularização Patológica/patologia , Especificidade de Órgãos , Fenótipo , Prosencéfalo/metabolismo , Prosencéfalo/patologia , Convulsões/genética , Convulsões/patologiaRESUMO
UNLABELLED: Hepatocellular carcinoma (HCC) has high mortality and no adequate treatment. Endocannabinoids interact with hepatic cannabinoid 1 receptors (CB1Rs) to promote hepatocyte proliferation in liver regeneration by inducing cell cycle proteins involved in mitotic progression, including Forkhead Box M1. Because this protein is highly expressed in HCC and contributes to its genesis and progression, we analyzed the involvement of the endocannabinoid/CB1R system in murine and human HCC. Postnatal diethylnitrosamine treatment induced HCC within 8 months in wild-type mice but fewer and smaller tumors in CB1R(-/-) mice or in wild-type mice treated with the peripheral CB1R antagonist JD5037, as monitored in vivo by serial magnetic resonance imaging. Genome-wide transcriptome analysis revealed CB1R-dependent, tumor-induced up-regulation of the hepatic expression of CB1R, its endogenous ligand anandamide, and a number of tumor-promoting genes, including the GRB2 interactome as well as Forkhead Box M1 and its downstream target, the tryptophan-catalyzing enzyme indoleamine 2,3-dioxygenase. Increased indoleamine 2,3-dioxygenase activity and consequent induction of immunosuppressive T-regulatory cells in tumor tissue promote immune tolerance. CONCLUSION: The endocannabinoid/CB1R system is up-regulated in chemically induced HCC, resulting in the induction of various tumor-promoting genes, including indoleamine 2,3-dioxygenase; and attenuation of these changes by blockade or genetic ablation of CB1R suppresses the growth of HCC and highlights the therapeutic potential of peripheral CB1R blockade.
Assuntos
Carcinoma Hepatocelular/etiologia , Neoplasias Hepáticas/etiologia , Receptor CB1 de Canabinoide/fisiologia , Animais , Carcinoma Hepatocelular/induzido quimicamente , Dietilnitrosamina , Progressão da Doença , Endocanabinoides/fisiologia , Proteína Forkhead Box M1 , Fatores de Transcrição Forkhead/fisiologia , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase , Neoplasias Hepáticas/induzido quimicamente , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias Experimentais/induzido quimicamente , Regulação para CimaRESUMO
Impulsivity, describing action without foresight, is an important feature of several psychiatric diseases, suicidality and violent behaviour. The complex origins of impulsivity hinder identification of the genes influencing it and the diseases with which it is associated. Here we perform exon-focused sequencing of impulsive individuals in a founder population, targeting fourteen genes belonging to the serotonin and dopamine domain. A stop codon in HTR2B was identified that is common (minor allele frequency > 1%) but exclusive to Finnish people. Expression of the gene in the human brain was assessed, as well as the molecular functionality of the stop codon, which was associated with psychiatric diseases marked by impulsivity in both population and family-based analyses. Knockout of Htr2b increased impulsive behaviours in mice, indicative of predictive validity. Our study shows the potential for identifying and tracing effects of rare alleles in complex behavioural phenotypes using founder populations, and indicates a role for HTR2B in impulsivity.
Assuntos
Comportamento Impulsivo/genética , Receptor 5-HT2B de Serotonina/genética , Receptor 5-HT2B de Serotonina/metabolismo , Animais , Encéfalo/metabolismo , Estudos de Casos e Controles , Linhagem Celular , Feminino , Finlândia , Efeito Fundador , Regulação da Expressão Gênica , Técnicas de Inativação de Genes , Genótipo , Humanos , Masculino , Transtornos Mentais/genética , Camundongos , Camundongos da Linhagem 129 , Camundongos Knockout , Linhagem , Polimorfismo de Nucleotídeo Único/genética , Testosterona/sangue , Testosterona/líquido cefalorraquidianoRESUMO
Identification of genes influencing complex traits is hampered by genetic heterogeneity, the modest effect size of many alleles, and the likely involvement of rare and uncommon alleles. Etiologic complexity can be simplified in model organisms. By genomic sequencing, linkage analysis, and functional validation, we identified that genetic variation of Grm2, which encodes metabotropic glutamate receptor 2 (mGluR2), alters alcohol preference in animal models. Selectively bred alcohol-preferring (P) rats are homozygous for a Grm2 stop codon (Grm2 *407) that leads to largely uncompensated loss of mGluR2. mGluR2 receptor expression was absent, synaptic glutamate transmission was impaired, and expression of genes involved in synaptic function was altered. Grm2 *407 was linked to increased alcohol consumption and preference in F2 rats generated by intercrossing inbred P and nonpreferring rats. Pharmacologic blockade of mGluR2 escalated alcohol self-administration in Wistar rats, the parental strain of P and nonpreferring rats. The causal role of mGluR2 in altered alcohol preference was further supported by elevated alcohol consumption in Grm2 (-/-) mice. Together, these data point to mGluR2 as an origin of alcohol preference and a potential therapeutic target.
Assuntos
Consumo de Bebidas Alcoólicas/genética , Códon de Terminação , Receptores de Glutamato Metabotrópico , Transmissão Sináptica/genética , Consumo de Bebidas Alcoólicas/tratamento farmacológico , Consumo de Bebidas Alcoólicas/metabolismo , Consumo de Bebidas Alcoólicas/patologia , Animais , Cruzamentos Genéticos , Antagonistas de Aminoácidos Excitatórios/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/genética , Ácido Glutâmico/metabolismo , Camundongos , Camundongos Knockout , Ratos , Ratos Wistar , Receptores de Glutamato Metabotrópico/antagonistas & inibidores , Receptores de Glutamato Metabotrópico/biossíntese , Receptores de Glutamato Metabotrópico/genética , Sinapses/genética , Sinapses/metabolismo , Transmissão Sináptica/efeitos dos fármacosRESUMO
Understanding inter-individual differences in stress response requires the explanation of genetic influences at multiple phenotypic levels, including complex behaviours and the metabolic responses of brain regions to emotional stimuli. Neuropeptide Y (NPY) is anxiolytic and its release is induced by stress. NPY is abundantly expressed in regions of the limbic system that are implicated in arousal and in the assignment of emotional valences to stimuli and memories. Here we show that haplotype-driven NPY expression predicts brain responses to emotional and stress challenges and also inversely correlates with trait anxiety. NPY haplotypes predicted levels of NPY messenger RNA in post-mortem brain and lymphoblasts, and levels of plasma NPY. Lower haplotype-driven NPY expression predicted higher emotion-induced activation of the amygdala, as well as diminished resiliency as assessed by pain/stress-induced activations of endogenous opioid neurotransmission in various brain regions. A single nucleotide polymorphism (SNP rs16147) located in the promoter region alters NPY expression in vitro and seems to account for more than half of the variation in expression in vivo. These convergent findings are consistent with the function of NPY as an anxiolytic peptide and help to explain inter-individual variation in resiliency to stress, a risk factor for many diseases.
Assuntos
Encéfalo/metabolismo , Emoções , Regulação da Expressão Gênica/genética , Variação Genética/genética , Neuropeptídeo Y/genética , Estresse Fisiológico/genética , Alelos , Ansiedade/genética , Transtornos de Ansiedade/genética , Encéfalo/fisiologia , Encéfalo/fisiopatologia , Expressão Facial , Finlândia/etnologia , Haplótipos/genética , Humanos , Linfócitos/metabolismo , Imageamento por Ressonância Magnética , Masculino , Neuropeptídeo Y/sangue , Peptídeos Opioides/metabolismo , Dor/genética , Polimorfismo de Nucleotídeo Único/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Estresse Fisiológico/psicologia , Estados Unidos/etnologia , População Branca/genéticaRESUMO
The hippocampus is a key brain region involved in both short- and long-term memory processes and may play critical roles in drug-associated learning and addiction. Using whole genome sequencing of mRNA transcripts (RNA-Seq) and immunoprecipitation-enriched genomic DNA (ChIP-Seq) coupled with histone H3 lysine 4 trimethylation (H3K4me3), we found extensive hippocampal gene expression changes common to both cocaine-addicted and alcoholic individuals that may reflect neuronal adaptations common to both addictions. However, we also observed functional changes that were related only to long-term cocaine exposure, particularly the inhibition of mitochondrial inner membrane functions related to oxidative phosphorylation and energy metabolism, which has also been observed previously in neurodegenerative diseases. Cocaine- and alcohol-related histone H3K4me3 changes highly overlapped, but greater effects were detected under cocaine exposure. There was no direct correlation, however, between either cocaine- or alcohol-related histone H3k4me3 and gene expression changes at an individual gene level, indicating that transcriptional regulation as well as drug-related gene expression changes are outcomes of a complex gene-regulatory process that includes multifaceted histone modifications.
Assuntos
Alcoolismo/metabolismo , Transtornos Relacionados ao Uso de Cocaína/metabolismo , Epigênese Genética , Hipocampo/metabolismo , Proteínas do Tecido Nervoso/biossíntese , Transcrição Gênica , Alcoolismo/genética , Transtornos Relacionados ao Uso de Cocaína/genética , Feminino , Perfilação da Expressão Gênica/métodos , Estudo de Associação Genômica Ampla/métodos , Humanos , Masculino , Proteínas do Tecido Nervoso/genéticaRESUMO
The mammalian liver regenerates upon tissue loss, which induces quiescent hepatocytes to enter the cell cycle and undergo limited replication under the control of multiple hormones, growth factors, and cytokines. Endocannabinoids acting via cannabinoid type 1 receptors (CB(1)R) promote neural progenitor cell proliferation, and in the liver they promote lipogenesis. These findings suggest the involvement of CB(1)R in the control of liver regeneration. Here we report that mice lacking CB(1)R globally or in hepatocytes only and wild-type mice treated with a CB(1)R antagonist have a delayed proliferative response to two-thirds partial hepatectomy (PHX). In wild-type mice, PHX leads to increased hepatic expression of CB(1)R and hyperactivation of the biosynthesis of the endocannabinoid anandamide in the liver via an in vivo pathway involving conjugation of arachidonic acid and ethanolamine by fatty-acid amide hydrolase. In wild-type but not CB(1)R(-/-) mice, PHX induces robust up-regulation of key cell-cycle proteins involved in mitotic progression, including cyclin-dependent kinase 1 (Cdk1), cyclin B2, and their transcriptional regulator forkhead box protein M1 (FoxM1), as revealed by ultrahigh-throughput RNA sequencing and pathway analysis and confirmed by real-time PCR and Western blot analyses. Treatment of wild-type mice with anandamide induces similar changes mediated via activation of the PI3K/Akt pathway. We conclude that activation of hepatic CB(1)R by newly synthesized anandamide promotes liver regeneration by controlling the expression of cell-cycle regulators that drive M phase progression.
Assuntos
Ácidos Araquidônicos/biossíntese , Regeneração Hepática , Fígado/metabolismo , Receptor CB1 de Canabinoide/metabolismo , Animais , Ciclo Celular , Endocanabinoides , Proteína Forkhead Box M1 , Fatores de Transcrição Forkhead/metabolismo , Fígado/citologia , Masculino , Camundongos , Camundongos Knockout , Mitose , Fosfatidilinositol 3-Quinases/metabolismo , Alcamidas Poli-Insaturadas , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptor CB1 de Canabinoide/antagonistas & inibidores , Receptor CB1 de Canabinoide/genética , Transdução de Sinais , Regulação para CimaRESUMO
Electroencephalographic (EEG) deficits in slow wave activity or Delta power (0.5-4 Hz) indicate disturbed sleep homeostasis and are hallmarks of depression. Sleep homeostasis is linked to restorative sleep and potential antidepressant response via non-rapid eye movement (NREM) slow wave sleep (SWS) during which neurons undergo essential repair and rejuvenation. Decreased Low Delta power (0.5-2 Hz) was previously reported in individuals with depression. This study investigated power levels in the Low Delta (0.5-<2 Hz), High Delta (2-4 Hz), and Total Delta (0.5-4 Hz) bands and their association with age, sex, and disrupted sleep in treatment-resistant depression (TRD). Mann-Whitney U tests were used to compare the nightly progressions of Total Delta, Low Delta, and High Delta in 100 individuals with TRD and 24 healthy volunteers (HVs). Polysomnographic parameters were also examined, including Total Sleep Time (TST), Sleep Efficiency (SE), and Wake after Sleep Onset (WASO). Individuals with TRD had lower Delta power during the first NREM episode (NREM1) than HVs. The deficiency was observed in the Low Delta band versus High Delta. Females with TRD had higher Delta power than males during the first NREM1 episode, with the most noticeable sex difference observed in Low Delta. In individuals with TRD, Low Delta power correlated with WASO and SE, and High Delta correlated with WASO. Low Delta power deficits in NREM1 were observed in older males with TRD, but not females. These results provide compelling evidence for a link between age, sex, Low Delta power, sleep homeostasis, and non-restorative sleep in TRD.
Assuntos
Ritmo Delta , Transtorno Depressivo Resistente a Tratamento , Eletroencefalografia , Polissonografia , Humanos , Feminino , Masculino , Pessoa de Meia-Idade , Adulto , Transtorno Depressivo Resistente a Tratamento/fisiopatologia , Ritmo Delta/fisiologia , Idoso , Caracteres Sexuais , Adulto Jovem , Transtornos do Sono-Vigília/fisiopatologia , Sono/fisiologiaRESUMO
Only ~20% of heavy drinkers develop alcohol cirrhosis (AC). While differences in metabolism, inflammation, signaling, microbiome signatures and genetic variations have been tied to the pathogenesis of AC, the key underlying mechanisms for this interindividual variability, remain to be fully elucidated. Induced pluripotent stem cell-derived hepatocytes (iHLCs) from patients with AC and healthy controls differ transcriptomically, bioenergetically and histologically. They include a greater number of lipid droplets (LDs) and LD-associated mitochondria compared to control cells. These pre-pathologic indicators are effectively reversed by Aramchol, an inhibitor of stearoyl-CoA desaturase. Bioenergetically, AC iHLCs have lower spare capacity, slower ATP production and their mitochondrial fuel flexibility towards fatty acids and glutamate is weakened. MARC1 and PNPLA3, genes implicated by GWAS in alcohol cirrhosis, show to correlate with lipid droplet-associated and mitochondria-mediated oxidative damage in AC iHLCs. Knockdown of PNPLA3 expression exacerbates mitochondrial deficits and leads to lipid droplets alterations. These findings suggest that differences in mitochondrial bioenergetics and lipid droplet formation are intrinsic to AC hepatocytes and can play a role in its pathogenesis.
Assuntos
Aciltransferases , Metabolismo Energético , Hepatócitos , Células-Tronco Pluripotentes Induzidas , Lipase , Gotículas Lipídicas , Cirrose Hepática Alcoólica , Mitocôndrias , Fosfolipases A2 Independentes de Cálcio , Humanos , Hepatócitos/metabolismo , Hepatócitos/patologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Gotículas Lipídicas/metabolismo , Cirrose Hepática Alcoólica/metabolismo , Cirrose Hepática Alcoólica/patologia , Cirrose Hepática Alcoólica/genética , Lipase/metabolismo , Lipase/genética , Mitocôndrias/metabolismo , Masculino , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Feminino , Pessoa de Meia-Idade , Adulto , Estresse OxidativoRESUMO
Complex psychiatric disorders are resistant to whole-genome analysis due to genetic and etiological heterogeneity. Variation in resting electroencephalogram (EEG) is associated with common, complex psychiatric diseases including alcoholism, schizophrenia, and anxiety disorders, although not diagnostic for any of them. EEG traits for an individual are stable, variable between individuals, and moderately to highly heritable. Such intermediate phenotypes appear to be closer to underlying molecular processes than are clinical symptoms, and represent an alternative approach for the identification of genetic variation that underlies complex psychiatric disorders. We performed a whole-genome association study on alpha (alpha), beta (beta), and theta (theta) EEG power in a Native American cohort of 322 individuals to take advantage of the genetic and environmental homogeneity of this population isolate. We identified three genes (SGIP1, ST6GALNAC3, and UGDH) with nominal association to variability of theta or alpha power. SGIP1 was estimated to account for 8.8% of variance in power, and this association was replicated in US Caucasians, where it accounted for 3.5% of the variance. Bayesian analysis of prior probability of association based upon earlier linkage to chromosome 1 and enrichment for vesicle-related transport proteins indicates that the association of SGIP1 with theta power is genuine. We also found association of SGIP1 with alcoholism, an effect that may be mediated via the same brain mechanisms accessed by theta EEG, and which also provides validation of the use of EEG as an endophenotype for alcoholism.
Assuntos
Eletroencefalografia , Genes/genética , Estudo de Associação Genômica Ampla , Proteínas Adaptadoras de Transdução de Sinal , Alcoolismo/genética , Transporte Biológico , Proteínas de Transporte/genética , Cromossomos Humanos Par 1/genética , Frequência do Gene/genética , Loci Gênicos/genética , Marcadores Genéticos , Complexo de Golgi/metabolismo , Humanos , Proteínas de Membrana , Fenótipo , Polimorfismo de Nucleotídeo Único/genética , Reprodutibilidade dos Testes , Estados Unidos , População Branca/genéticaRESUMO
BACKGROUND: As a model organism in biomedicine, the rhesus macaque (Macaca mulatta) is the most widely used nonhuman primate. Although a draft genome sequence was completed in 2007, there has been no systematic genome-wide comparison of genetic variation of this species to humans. Comparative analysis of functional and nonfunctional diversity in this highly abundant and adaptable non-human primate could inform its use as a model for human biology, and could reveal how variation in population history and size alters patterns and levels of sequence variation in primates. RESULTS: We sequenced the mRNA transcriptome and H3K4me3-marked DNA regions in hippocampus from 14 humans and 14 rhesus macaques. Using equivalent methodology and sampling spaces, we identified 462,802 macaque SNPs, most of which were novel and disproportionately located in the functionally important genomic regions we had targeted in the sequencing. At least one SNP was identified in each of 16,797 annotated macaque genes. Accuracy of macaque SNP identification was conservatively estimated to be >90%. Comparative analyses using SNPs equivalently identified in the two species revealed that rhesus macaque has approximately three times higher SNP density and average nucleotide diversity as compared to the human. Based on this level of diversity, the effective population size of the rhesus macaque is approximately 80,000 which contrasts with an effective population size of less than 10,000 for humans. Across five categories of genomic regions, intergenic regions had the highest SNP density and average nucleotide diversity and CDS (coding sequences) the lowest, in both humans and macaques. Although there are more coding SNPs (cSNPs) per individual in macaques than in humans, the ratio of dN/dS is significantly lower in the macaque. Furthermore, the number of damaging nonsynonymous cSNPs (have damaging effects on protein functions from PolyPhen-2 prediction) in the macaque is more closely equivalent to that of the human. CONCLUSIONS: This large panel of newly identified macaque SNPs enriched for functionally significant regions considerably expands our knowledge of genetic variation in the rhesus macaque. Comparative analysis reveals that this widespread, highly adaptable species is approximately three times as diverse as the human but more closely equivalent in damaging variation.
Assuntos
Variação Genética , Macaca mulatta/genética , Adulto , Animais , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Polimorfismo de Nucleotídeo ÚnicoRESUMO
In humans, it has been demonstrated that the serotonin transporter linked polymorphic region (5-HTTLPR) genotype moderates risk in the face of adversity. One mechanism by which stress could interact with genotype is via epigenetic modifications. We wanted to examine whether stress interacted with genotype to predict binding of a histone 3 protein trimethylated at lysine 3 (H3K4me3) that marks active promoters. The brains (N = 61) of male rhesus macaques that had been reared in the presence or absence of stress were archived and the hippocampusi dissected. Chromatin immunoprecipitation was performed with an antibody against H3K4me3 followed by sequencing on a SolexaG2A. The effects of age, genotype (5-HTTLPR long/long vs. short), and stress exposure (peer-reared vs. mother-reared) on levels of H3K4me3 binding were determined. We found effects of age and stress exposure. There was a decline in H3K4me3 from preadolescence to postadolescence and lower levels in peer-reared monkeys and no effects of genotype. When we controlled for age, however, we found that there were effects of 5-HTTLPR genotype and rearing condition on H3K4me3 binding. In a larger sample, we observed that cerebrospinal fluid 5-hydroxyindoleacetic acid levels were subject to interactive effects among age, rearing history, and genotype. Genes containing both genetic selection and epigenetic regulation may be particularly important in stress adaptation and development. We find evidence for selection at the solute carrier family C6 member 4 gene and observe epigenetic reorganization according to genotype, stress, and age. These data suggest that developmental stage may moderate effects of stress and serotonin transporter genotype in the emergence of alternative adaptation strategies and in the vulnerability to developmental or psychiatric disorders.
Assuntos
Epigênese Genética , Interação Gene-Ambiente , Hipocampo/metabolismo , Histonas/genética , Proteínas da Membrana Plasmática de Transporte de Serotonina/genética , Estresse Psicológico/genética , Fatores Etários , Animais , Comportamento Animal , Genótipo , Histonas/metabolismo , Ácido Hidroxi-Indolacético/líquido cefalorraquidiano , Macaca mulatta , Masculino , Privação Materna , Regiões Promotoras Genéticas , Seleção Genética , Proteínas da Membrana Plasmática de Transporte de Serotonina/metabolismo , Estresse Psicológico/metabolismoRESUMO
Fetal Alcohol Spectrum Disorder (FASD) encompasses an array of effects of prenatal alcohol exposure (PAE), including physical abnormalities and cognitive and behavioral deficits. Disruptions of cortical development have been implicated in multiple PAE studies, with deficits including decreased progenitor proliferation, disrupted neuronal differentiation, aberrant radial migration of pyramidal neurons, and decreased cortical thickness. While several mechanisms of alcohol teratogenicity have been explored, how specific cell types in the brain at different developmental time points may be differentially affected by PAE is still poorly understood. In this study, we used single nucleus RNA sequencing (snRNAseq) to investigate whether moderate PAE from neurulation through peak cortical neurogenesis induces cell type-specific transcriptomic changes in the developing murine brain. Cluster analysis identified 25 neuronal cell types, including subtypes of radial glial cells (RGCs), intermediate progenitor cells (IPCs), projection neurons, and interneurons. Only Wnt-expressing cortical hem RGCs showed a significant decrease in the percentage of cells after PAE, with no cell types showing PAE-induced apoptosis as measured by caspase expression. Cell cycle analysis revealed only a subtype of RGCs expressing the downstream Wnt signaling transcription factor Tcf7l2 had a decreased percentage of cells in the G2/M phase of the cell cycle, suggesting decreased proliferation in this RGC subtype and further implicating disrupted Wnt signaling after PAE at this early developmental timepoint. An increased pseudotime score in IPC and projection neuron cell types indicated that PAE led to increased or premature differentiation of these cells. Biological processes affected by PAE included the upregulation of pathways related to synaptic activity and neuronal differentiation and downregulation of pathways related to chromosome structure and the cell cycle. Several cell types showed a decrease in Wnt signaling pathways, with several genes related to Wnt signaling altered by PAE in multiple cell types. As Wnt has been shown to promote proliferation and inhibit differentiation at earlier stages in development, the downregulation of Wnt signaling may have resulted in premature neuronal maturation of projection neurons and their intermediate progenitors. Overall, these findings provide further insight into the cell type-specific effects of PAE during early corticogenesis.
RESUMO
Abuse of psychostimulants, including amphetamines (AMPHs), is a major public health problem with profound psychiatric, medical, and psychosocial complications. The actions of these drugs at the dopamine transporter (DAT) play a critical role in their therapeutic efficacy as well as their liability for abuse and dependence. To date, however, the mechanisms that mediate these actions are not well-understood, and therapeutic interventions for AMPH abuse have been limited. Drug exposure can induce broad changes in gene expression that can contribute to neuroplasticity and effect long-lasting changes in neuronal function. Identifying genes and gene pathways perturbed by drug exposure is essential to our understanding of the molecular basis of drug addiction. In this study, we used Drosophila as a model to examine AMPH-induced transcriptional changes that are DAT-dependent, as those would be the most relevant to the stimulatory effects of the drug. Using this approach, we found genes involved in the control of mRNA translation to be significantly upregulated in response to AMPH in a DAT-dependent manner. To further prioritize genes for validation, we explored functional convergence between these genes and genes we identified in a genome-wide association study of AMPH sensitivity using the Drosophila Genetic Reference Panel. We validated a number of these genes by showing that they act specifically in dopamine neurons to mediate the behavioral effects of AMPH. Taken together, our data establish Drosophila as a powerful model that enables the integration of behavioral, genomic and transcriptomic data, followed by rapid gene validation, to investigate the molecular underpinnings of psychostimulant action.