A variety of neurological disorders, including Alzheimer's disease, Parkinson's disease, major depressive disorder, dyslexia and autism, are differentially prevalent between females and males. To better understand the possible molecular basis for the sex-biased nature of neurological disorders, we measured both mRNA and protein in the hippocampus of female and male mice at 1, 2, and 4 months of age with RNA-sequencing and mass-spectrometry respectively. Differential expression analyses identify 2699 genes that are differentially expressed between animals of different ages. 198 transcripts are differentially expressed between females and males at one or more ages. The number of transcripts that are differentially expressed between females and males is greater in adult animals than in younger animals. Additionally, we identify 69 transcripts that show complex and sex-specific patterns of temporal regulation across all ages, 8 of which are heat-shock proteins. We also find a modest correlation between levels of mRNA and protein in the mouse hippocampus (Rho = 0.53). This study adds to the substantial body of evidence for transcriptomic regulation in the hippocampus during postnatal development. Additionally, this analysis reveals sex differences in the transcriptome of the developing mouse hippocampus, and further clarifies the need to include both female and male mice in longitudinal studies involving molecular changes in the hippocampus. Overall design: Hippocampal mRNA from 1, 2, and 4 month old male and female B6 mice were analyzed by RNA sequencing of 5 biological replicates using an Illumina HiSeq 2500
Sex differences in the molecular signature of the developing mouse hippocampus.
Sex, Age, Specimen part, Cell line, Subject
View SamplesNumerous neurological disorders, including Alzheimer's disease, display a sex-biased prevalence. To identify molecular correlates of this sex bias, we investigated sex-differences in molecular pathology in the hippocampus using the 5XFAD mouse model of Alzheimer's disease during early stages of disease progression (1, 2, and 4 months of age). Overall design: Hippocampal mRNA from 1, 2, and 4 month old male and female 5XFAD mice were analyzed by RNA sequencing of 5 biological replicates using an Illumina HiSeq 2500
Sex-biased hippocampal pathology in the 5XFAD mouse model of Alzheimer's disease: A multi-omic analysis.
Sex, Age, Specimen part, Cell line, Subject
View SamplesIdentifying sex differences in gene expression within the brain is critical for determining why multiple neurological and behavioral disorders differentially affect males and females. Several are more common or severe in males (e.g., autism and schizophrenia) or females (e.g., Alzheimer’s disease and depression). We analyzed transcriptomic data from the mouse hippocampus of six inbred strains (129S1/SvImJ, A/J, C57BL/6J, DBA/1J, DBA/2J and PWD/Ph), to provide a perspective on differences between male and female gene expression. Our data show that: 1) significant gene expression differences in males versus females varies substantially across the strains, 2) 12 genes exist that are differentially expressed across the inbred strains (termed core genes), and 3) there are >2,600 significantly differentially expressed genes (DEGs) among the strains (termed non-core genes). We found that DBA/2J uniquely has a substantial majority (89%) of DEGs that are more highly expressed in females than males; 129/SvImJ is the most strongly male-biased with a majority (69%) of DEGs that are more highly expressed in males. To gain insight into the sex-biased DEGs, we examined gene ontology, pathway and phenotype enrichment and found significant enrichment in phenotypes related to abnormal nervous system morphology and physiology, among others. In addition, several pathways are enriched significantly, including Alzheimer’s disease (AD), with 32 genes implicated in AD, 8 of which are male-biased. Three of the male-biased genes have been implicated in a neuroprotective role in AD. Our transcriptomic data provide new insight into understanding the possible genetic bases for sex-specific susceptibility and severity of brain disorders. Overall design: Hippocampal mRNA from adult males and females of six inbred strains of mice were analyzed by RNA sequencing of 3 biological replicates using an Illumina HiSeq 2500
Transcriptomic analysis of the hippocampus from six inbred strains of mice suggests a basis for sex-specific susceptibility and severity of neurological disorders.
Sex, Age, Specimen part, Cell line, Subject
View SamplesThe analysis of capped RNAs by massively parallel sequencing has identified a large number of previously unknown transcripts, some of which are small RNAs and others are 5 truncated forms of RefSeq genes. The latter may be generated by endonuclease cleavage or by stalling of Xrn1 at defined sites. With the exception of promoter-proximal transcripts the caps on all of these are added post-transcriptionally by a cytoplasmic capping enzyme complex that includes capping enzyme and a kinase that converts 5-monophosphate ends to a diphosphate capping substrate. We previously described a modified form of capping enzyme with dominant negative activity against cytoplasmic capping (DN-cCE). A tet-inducible form of this was used to identify substrates for cytoplasmic capping by treating cytoplasmic RNA from control and induced cells with and without Xrn1. Surviving RNA was analyzed on Affymetrix Human Exon 1.0 arrays and scored for changes in probe intensity as a function of its position on each RefSeq gene to derive a factor (alpha) that could be compared between sets. Notably, transcriptome-wide changes were not evident unless RNA was treated with Xrn1. This analysis identified 2,666 uncapped mRNAs in uninduced cells, 672 mRNAs that appeared in the uncapped pool in cells expressing DN-cCE, and 835 mRNAs that were in both populations. Changes in cap status of 10 re-capping targets and 5 controls were assessed by 3 independent measures; susceptibility to Xrn1, recovery with a biotin-tagged DNA primer after ligating a complementary RNA oligonucleotide to uncapped 5 ends, and binding or exclusion from a high affinity cap-binding matrix comprised of immobilized eIF4E and the corresponding binding domain of eIF4G.
Identification of cytoplasmic capping targets reveals a role for cap homeostasis in translation and mRNA stability.
Cell line
View SamplesThe developmental transition to motherhood requires gene expression changes that alter the brain to prepare and drive the female to perform maternal behaviors. Furthermore, it is expected that the many physiological changes accompanying pregnancy and postpartum stages will impact brain gene expression patterns. To understand how extensive these gene expression changes are, we examined the global transcriptional response broadly, by examining four different brain regions: hypothalamus, hippocampus, neocortex, and cerebellum. Further, to understand the time course of these changes we performed RNA-sequencing analyses on mRNA derived from virgin females, two pregnancy time points and three postpartum time points. We find that each brain region and time point shows a unique molecular signature, with only 49 genes differentially expressed in all four regions, across the time points. Additionally, several genes previously implicated in underlying postpartum depression change expression. This study serves as a comprehensive atlas of gene expression changes in the maternal brain in the cerebellum, hippocampus, hypothalamus, and neocortex. At each of the time points analyzed, all four brain regions show extensive changes, suggesting that pregnancy, parturition, and postpartum maternal experience substantially impacts diverse brain regions. Overall design: Libraries were prepared from three independent biological replicates, mRNA for each biological replicate was derived from a single mouse brain, with each mouse brain being used to collect all four brain regions.
An Examination of Dynamic Gene Expression Changes in the Mouse Brain During Pregnancy and the Postpartum Period.
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View SamplesAccumulating evidence suggests that mitochondrial dysfunction underlies the pathophysiology of bipolar disorder (BD) and schizophrenia (SZ). We performed large-scale DNA microarray analysis of postmortem brains of patients with BD or SZ, and examined expression patterns of mitochondria-related genes. We found a global down-regulation of mitochondrial genes, such as those encoding respiratory chain components, in BD and SZ samples, even after the effect of sample pH was controlled. However, this was likely due to the effects of medication. Medication-free patients with BD showed tendency of up-regulation of subset of mitochondrial genes. Our findings support the mitochondrial dysfunction hypothesis of BD and SZ pathologies. However, it may be the expression changes of a small fraction of mitochondrial genes rather than the global down-regulation of mitochondrial genes. Our findings warrant further study of the molecular mechanisms underlying mitochondrial dysfunction in BD and SZ.
Altered expression of mitochondria-related genes in postmortem brains of patients with bipolar disorder or schizophrenia, as revealed by large-scale DNA microarray analysis.
No sample metadata fields
View SamplesWe performed the oligonucleotide microarray analysis in bipolar disorder, major depression, schizophrenia, and control subjects using postmortem prefrontal cortices provided by the Stanley Foundation Brain Collection. By comparing the gene expression profiles of similar but distinctive mental disorders, we explored the uniqueness of bipolar disorder and its similarity to other mental disorders at the molecular level. Notably, most of the altered gene expressions in each disease were not shared by one another, suggesting the molecular distinctiveness of these mental disorders. We found a tendency of downregulation of the genes encoding receptor, channels or transporters, and upregulation of the genes encoding stress response proteins or molecular chaperons in bipolar disorder. Altered expressions in bipolar disorder shared by other mental disorders mainly consisted of upregulation of the genes encoding proteins for transcription or translation. The genes identified in this study would be useful for the understanding of the pathophysiology of bipolar disorder, as well as the common pathophysiological background in major mental disorders at the molecular level.
Molecular characterization of bipolar disorder by comparing gene expression profiles of postmortem brains of major mental disorders.
No sample metadata fields
View SamplesDietary polyunsaturated fatty acids (PUFA) act as potent natural hypolipidemics and are linked to many health benefits in humans and in animal models. Mice fed long-term a high fat diet, in which medium-chain alpha linoleic acid (ALA) was partially replaced by long-chain docosahexaenoic (DHA) and eicosapentaenoic (EPA) fatty acids, showed reduced accumulation of body fat and prevention of insulin resistance, besides increased mitochondrial beta-oxidation in white adipose tissue and decreased plasma lipids. ALA, EPA and DHA all belong to PUFA of n-3 series. The intestine is a gatekeeper organ for ingested lipids. To examine the potential contribution of the intestine in the beneficial effects of EPA and DHA, this study assessed gene expression changes using whole genome microarray analysis on small intestinal scrapings. The main biological process affected was lipid metabolism. Fatty acid uptake, peroxisomal and mitochondrial beta-oxidation, and omega-oxidation of fatty acids were all increased. Quantitative real time PCR and intestinal fatty acid oxidation measurements ([14C(U)]-palmitate) confirmed significant gene expression differences in a dose-dependent manner. Furthermore, no major changes in the expression of lipid metabolism genes were observed in colonic scrapings. In conclusion, we show that marine n-3 fatty acids regulate small intestinal gene expression patterns. Since this organ contributes significantly to whole organism energy use, this adaptation of the small intestine may contribute to the complex and observed beneficial physiological effects of these natural compounds under conditions that will normally lead to development of obesity and diabetes.
Induction of lipid oxidation by polyunsaturated fatty acids of marine origin in small intestine of mice fed a high-fat diet.
No sample metadata fields
View SamplesRationale: Respiratory syncytial virus (RSV) is the leading cause of acute lower respiratory tract infections and hospitalizations in infants worldwide. Known risk factors, however, incompletely explain the variability of RSV disease severity among children. We postulate that severity of RSV infection is influenced in part by modulation of the host immune response by the local microbial ecosystem at the time of infection. Objectives: To define whether different nasopharyngeal microbiota profiles are associated with distinct host transcriptome profiles and severity in children with RSV infection. Methods: We analyzed the nasopharyngeal microbiota profiles of young children with mild and severe RSV disease and healthy matched controls by 16S-rRNA sequencing. In parallel, we analyzed whole blood gene expression profiles to study the relationship between microbial community composition, the RSV-induced host transcriptional response and clinical disease severity. Measurements and Main results: We identified five nasopharyngeal microbiota profiles characterized by enrichment of H. influenzae, Streptococcus, Corynebacterium, Moraxella or S. aureus. RSV infection and RSV hospitalization were positively associated with H. influenzae and Streptococcus, and negatively associated with S. aureus abundance, independent of age. The host response to RSV was defined by overexpression of interferon-related genes, and this was independent of the microbiota composition. On the other hand, transcriptome profiles of RSV infected children with H. influenzae and Streptococcus-dominated microbiota were characterized by greater overexpression of genes linked to toll-like receptor-signaling and neutrophil activation and were more frequently hospitalized Conclusions: Our data suggest an immunomodulatory role for the resident nasopharyngeal microbial community early in RSV infection, potentially affecting RSV disease severity.
Nasopharyngeal Microbiota, Host Transcriptome, and Disease Severity in Children with Respiratory Syncytial Virus Infection.
Sex, Specimen part, Disease, Race
View SamplesA cardinal symptom of Major Depressive Disorder (MDD) is the disruption of circadian patterns. Yet, to date, there is no direct evidence of circadian clock dysregulation in the brains of MDD patients. Circadian rhythmicity of gene expression has been observed in animals and peripheral human tissues, but its presence and variability in the human brain was difficult to characterize. Here we applied time-of-death analysis to gene expression data from high-quality postmortem brains, examining 24-hour cyclic patterns in six cortical and limbic regions of 55 subjects with no history of psychiatric or neurological illnesses ('Controls') and 34 MDD patients. Our dataset covered ~12,000 transcripts in the dorsolateral prefrontal cortex (DLPFC), anterior cingulate cortex (AnCg), hippocampus (HC), amygdala (AMY), nucleus accumbens (NAcc) and cerebellum (CB). Several hundred transcripts in each region showed 24-hour cyclic patterns in Controls, and >100 transcripts exhibited consistent rhythmicity and phase-synchrony across regions. Among the top ranked rhythmic genes were the canonical clock genes BMAL1(ARNTL), PER1-2-3, NR1D1(REV-ERB), DBP, BHLHE40(DEC1), and BHLHE41(DEC2). The phasing of known circadian genes was consistent with data derived from other diurnal mammals. Cyclic patterns were much weaker in MDD brains, due to shifted peak timing and potentially disrupted phase relationships between individual circadian genes. This is the first transcriptome-wide analysis of cyclic patterns in the human brain and demonstrates a rhythmic rise and fall of gene expression in regions outside of the suprachiasmatic nucleus in control subjects. The description of its breakdown in MDD suggest novel molecular targets for treatment of mood disorders.
Circadian patterns of gene expression in the human brain and disruption in major depressive disorder.
Subject
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