Dataset Information

Targeted quantification of detergent-insoluble RNA-binding proteins in Alzheimer’s disease reveals disease-specific coaggregation signatures

ABSTRACT: Core spliceosome and related RNA-binding proteins aggregate in Alzheimer’s disease (AD) brain even in early asymptomatic stages (AsymAD) of disease. To assess the specificity of RNA-binding protein aggregation in AD, we developed a targeted mass spectrometry approach to quantify broad classes of RNA-binding proteins with other pathological proteins including Tau and amyloid beta (Aβ) in detergent insoluble fractions from AD brain and that of other dementias. In total, we quantified 870 peptides from 385 detergent-insoluble RNA-binding proteins across 44 cortical tissues including controls, AsymAD, AD, and Parkinson’s Disease (PD). Relative levels of specific insoluble RNA-binding proteins across different disease groups correlated with accumulation of Aβ and Tau aggregates. RNA-binding proteins, including splicing factors with homology to the basic-acidic dipeptide repeats of U1-70K, preferentially aggregated in AsymAD and AD. In contrast, PD brain aggregates were relatively depleted of many RNA-binding proteins compared to AsymAD and AD groups. Correlation network analyses resolved 29 distinct modules of co-aggregating proteins including modules linked to spliceosome assembly, nuclear speckles and RNA splicing. Modules related to spliceosome assembly and nuclear speckles progressively increased in insolubility across progressive AD stages, whereas the RNA splicing module was decreased specifically in PD. Collectively, this work identifies classes of RNA-binding proteins that distinctly co-aggregate in detergent-insoluble fractions across neurodegenerative diseases.

INSTRUMENT(S): Q Exactive Plus

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Brain

DISEASE(S): Parkinson's Disease,Alzheimer's Disease

SUBMITTER: Eric Dammer

LAB HEAD: Nicholas T. Seyfried

PROVIDER: PXD022144 | Pride | 2021-03-17

REPOSITORIES: Pride

ACCESS DATA

Similar Datasets

Project description:Approximately 35 million people worldwide suffer from Alzheimer’s disease (AD). Existing therapeutics, while moderately effective, are currently unable to stem the widespread rise in AD prevalence. AD is associated with an increase in amyloid beta (A) oligomers and hyperphosphorylated tau, along with cognitive impairment and neurodegeneration. Several antidepressants have shown promise in improving cognition and alleviating oxidative stress in AD but have failed as long-term therapeutics. In this study, amitriptyline, an FDA-approved tricyclic antidepressant, was administered orally to aged and cognitively impaired transgenic AD mice (3xTgAD). After amitriptyline treatment, cognitive behavior testing demonstrated that there was a significant improvement in both long- and short-term memory retention. Amitriptyline treatment also caused a significant potentiation of non-toxic A monomer with a concomitant decrease in toxic oligomer A load, compared to vehicle-treated 3xTgAD controls. In addition, amitriptyline administration caused a significant increase in dentate gyrus neurogenesis as well as increases in expression of neurosynaptic marker proteins. Amitriptyline treatment resulted in increases in hippocampal brain-derived neurotrophic factor protein as well as increased tyrosine phosphorylation of its cognate receptor (TrkB). These results indicate that amitriptyline has significant beneficial actions in aged and damaged AD brains and that it shows promise as a tolerable novel therapeutic for the treatment of AD. Male 3xTgAD mice, 14 months of age, were maintained on a 12hr light dark cycle in pathogen free conditions. Animals received food and water ad libitum. The test group received 100ug/g body weight amitriptyline-hydrochloride per os in their drinking water (Sigma-Aldrich, St. Louis MO) for 4 months (n = 15), and the control group received water (n = 15). The Hippocampus and Cortex were removed from 3 replicates of each group and RNA purification was done using glass bead disruption followed by the RNEasy Mini Kit (Qiagen, Valencia, CA) according to the manufacturer's instructions. The RNA was examined for quantity and quality using an Agilent Bioanalyzer 2100 (Agilent Technologies, Palo Alto, CA). The samples were hybridized to Illumina's SentrixMouse Ref-8 v2. Expression BeadChips (Illumina, San Diego, CA).

Project description:Cis-9, trans-11-conjugated linoleic acid (c9, t11-CLA), a functional fatty acid, is one of the research hotspots in the fields of functional dairy products development because of its multiple beneficial effects in humans and animals. In milk, most c9, t11-CLA is de novo synthesized from trans-11-octadecenoic acid (TVA) and it is confirmed that genes such as stearoyl-coA desaturase 1 (SCD1) play a key role in the synthesis. However, few studies have been reported to deeply elucidate the SCD1-dependent molecular mechanism of cis9, trans11-CLA synthesis and its relationship with the pathways of energy metabolism and lipid metabolism. Therefore, in the present study, MAC-T cells were divided into three groups: CAY group (SCD1-inhibited MAC-T cell model with the addition of CAY, TVA), TVA group (only TVA), and Control group (without CAY, TVA). The relative mRNA expression of SCD1 was measured using real-time PCR, while TVA accumulation and c9, t11 -CLA synthesis were analyzed using gas chromatography (GC). The SCD1-related proteins were firstly screened in MAC-T cells by Tandem Mass Tag (TMT)-based quantitative proteomics analysis, then their functions were annotated by bioinformatic analysis, and finally their relationships with SCD1 were evaluated by parallel reaction monitoring (PRM) analysis and small RNA interference. The results showed that the deficiency of SCD1 led by CAY10566 blocked the synthesis of c9, t11-CLA in MAC-T cells. Sixty-one SCD1-associated proteins were screened and found to be mainly involved in the pathways of energy metabolism and lipid metabolism, such as glycolytic pathway, pentose phosphate pathway, fatty acid elongation pathway, and unsaturated fatty acid biosynthesis. Among these genes, 17 proteins were validated under the PRM analysis. PGAM1 (phosphoglycerate mutase 1), TPI1 (triosephosphate isomerase 1), LDHB (lactate dehydrogenase B), and ALDOA (aldolase, fructose-bisphosphate A) were verified to have a negative relationships with SCD1. This study furthered our understanding of the molecular mechanisms of c9, t11-CLA synthesis in the mammary glands of dairy cows.

Project description:The decline of cognitive function is a feature of normal human aging and is exacerbated in AlzheimerM-bM-^@M-^Ys disease (AD). DNA repair declines in brain cells during normal aging and even more so in AD. Here we show that experimental reduction in levels of the base excision repair enzyme, DNA polymerase M-NM-2 (Polb) renders neurons vulnerable to age-related dysfunction and degeneration in a mouse model of AD. Whereas 3xTgAD mice exhibit age-related extracellular amyloid b-peptide (Ab) accumulation and cognitive deficits, but no neuronal death, 3xTg/Polb+/- mice accumulates intracellular Ab and neurons die in the hippocampus and cerebral cortex. The DNA repair-deficient 3xTgAD mice exhibited increased DNA strand breaks and apoptotic caspase activation with loss of hippocampal volume, and impaired synaptic plasticity and memory retention. Molecular profiling revealed remarkable similarities in gene expression alterations in brain cells of AD patients and 3xTgAD/Polb+/- mice including multiple abnormalities suggestive of impaired cellular bioenergetics. Our findings demonstrate that a modest decrement in oxidative DNA damage processing is sufficient to render neurons vulnerable to AD-related pathogenic molecular and cellular alterations that result in the dysfunction and death of neurons, and associated cognitive deficits. 4 mouse strains were used in these experiments, the 3xTgAD and Pol M-NM-2 (+/-) mice were bred at the National Institute on Aging (Baltimore, Maryland). The original line 3xTgAD line was generated as described previously (Oddo, et. al 2003) and possess APPswe, PS1M146V, and tauP301L mutations. DNA polymerase beta heterozygous mice, Pol M-NM-2 (+/-), were crossed with the 3xTgAD mice to generate a 3xTgAD/Pol M-NM-2 (+/-) mouse. The Wt strain is C57Bl/6. At 20 months of age these mice were euthanized by cervical dislocation, the brain removed from the skull and dissected into regions of interest, the prefrontal cortex was used for the microarray studies.

Project description:Cockayne syndrome (CS) is an accelerated aging disorder characterized by progressive neurodegeneration caused by mutations in the genes encoding the DNA repair proteins CSA or CSB. Csbm/m mice were given a high-fat, caloric-restricted or resveratrol-supplemented diet. The high-fat diet rescued the phenotype of Csbm/m mice at the metabolic, transcriptomic and behavioral levels. Additional analysis suggests that the premature aging seen in CS mice, nematodes and human cells results from aberrant PARP activation due to deficient DNA repair leading to decreased SIRT1 activity and mitochondrial dysfunction. Notably, Î²-hydroxybutyrate levels are increased by the high-fat diet; and Î²-hydroxybutyrate, PARP inhibition, or NAD+ supplementation can activate SIRT1 and rescue CS-associated phenotypes. Mechanistically, CSB is able to displace activated PARP1 from damaged DNA to limit its activity. This study connects two emerging longevity metabolites, Î²-hydroxybutyrate and NAD+, through the deacetylase SIRT1 and suggests possible interventions for CS. 4-month-old mice, WT and Csbm/m on a C57BL/6 background, were fed a standard AIN-93G diet (SD; carbohydrate:protein:fat ratio of 64:19:17 percent of kcal) ad libitum or at 40% CR, a SD supplemented with 100 mg/kgchow resveratrol ad libitum, or a high-fat diet ad libitum consisting of AIN-93G with 60% of calories from fat, primarily hydrogenated coconut oil (HFD; carbohydrate:protein:fat ratio of 16:23:61). Each group was on the specified diet for 8 months, after which the mice were sacrificed and the cerebellum was removed. For nicotinamide treatments, 4- or 18-month-old WT and Csbm/m mice were given daily injections of nicotinamide riboside (NR) (500 mg/kg/d, ip) or saline for one week, after which the mice were sacrificed and the cerebellum was removed. RNA was extracted from the cerebellums of all mice using Trizol, and RNA quality and quantity were tested using an Agilent 2100 BioAnalyzer with RNA 6000 nano chips. RNA was labeled using the standard Illumina protocol for Illumina TotalPrep RNA Amplification Kit. Labeled RNA was hybridized to Illumina's Sentrix MouseRef-8 v2 Expression BeadChips (Illumina, San Diego, CA) overnight and washed, stained and scanned the next day.

Project description:Increased expression of SIRT1 extends the lifespan of lower organisms and delays the onset of age-related diseases in mammals. Here, we show that SRT2104, a synthetic small molecule activator of SIRT1, extends both mean and maximal lifespan of mice fed a standard diet. This is accompanied by improvements in health, including enhanced motor coordination, performance, bone mineral density and insulin sensitivity associated with higher mitochondrial content and decreased inflammation. Short-term SRT2104 treatment preserves bone and muscle mass in an experimental model of atrophy. These results demonstrate it is possible to design a small molecule that can slow aging and delay multiple age-related diseases in mammals, supporting the therapeutic potential of SIRT1 activators in humans. Key words: Sirtuins, lifespan, healthspan, osteoporosis, muscle wasting, inflammation Groups of 28 week old male C57BL6/J mice were maintained for the rest of their lives or until sacrifice on either an ad libitum AIN-93G SD diet, an ad libitum AIN-93G diet supplemented with SRT2104 or a caloric restricted AIN-93G diet consisting of 60% of what the ad lib animals ate. SRT2104 was added at a dose of 1.33 g drug per kg of chow, formulated to provide daily doses of approximately 100 mg drug per kg bodyweight to the mice. 5 mice from each group were selected after 41 weeks and RNA was extracted from both muscle and liver tissue using 1.0mm glass beads in a Precellys 24 Tissue Homogenizer and Qiagen RNeasy Mini Kits for Fibrous Tissue according to manufacturer's specifications. Quality and quantity of the total RNA was checked with the Agilent 2100 bioanalyzer using RNA 6000 Nano chips. RNA samples were labeled using the Illumina TotalPrep RNA Amplification Kit. In short, 0.5ug of total RNA was first converted into single-stranded cDNA with reverse transcriptase using an oligo-dT primer containing the T7 RNA polymerase promoter site and then copied to produce double-stranded cDNA molecules. The double stranded cDNA was cleaned and concentrated with the supplied columns and used in an overnight in-vitro transcription reaction where single-stranded RNA (cRNA) was generated and labeled by incorporation of biotin-16-UTP. Arrays were hybridized using a total of 0.75ug of biotin-labeled cRNA at 58 degrees C for 16 hours to Illumina's Sentrix MouseRef-8 v2 Expression BeadChips. Each BeadChip has ~24,000 well-annotated RefSeq transcripts with approximately 30-fold redundancy. The arrays were washed, blocked and the biotin labeled cRNA was detected by staining with streptavidin-Cy3. Arrays were scanned at a resolution of 0.8um using the Beadstation 500 X from Illumina and the data was extracted using the Illumina GenomeStudio software(v1.6.0). Any spots at or below the background were filtered out using an Illumina detection p value of 0.02 and above. The natural log of all remaining scores were used to find the avg and std of each array and the z-score normalization was calculated and presented below. Z-score = (raw value - avg)/std.

Dataset Information

Targeted quantification of detergent-insoluble RNA-binding proteins in Alzheimer’s disease reveals disease-specific coaggregation signatures

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure