ASPA
Aspartoacylase (EC 3.5.1.15) (Aminoacylase-2) (ACY-2) [ACY2] [ASP]
Publications[править]
B-vitamins may influence DNA methylation. We studied the effects of vitamin D Ca B versus D Ca on epigenetic age markers and biological age. Participants (mean ± SD of age = 68.4 ± 10.1 years) were randomized to receive 1200 IE vitamin D3 plus 800 mg Ca-carbonate alone (n = 31) or with 0.5 mg B9, 50 mg B6, and 0.5 mg B12 (n = 32). The CpG methylation of 3 genes (ASPA, ITGA2B, and PDE4C) and the changes in methylation were compared between the groups after 1 year. The changes of ASPA methylation from baseline were higher in the D Ca B than in the D Ca group (1.40 ± 4.02 vs. -0.96 ± 5.12, respectively; p = 0.046, adjusted for age, sex, and baseline methylation). The changes in PDE4C from baseline were slightly higher in the D Ca B group (1.95 ± 3.57 vs. 0.22 ± 3.57; adjusted p = 0.062). Methylation of ITGA2B and its changes from baseline were not different between the intervention groups. Sex-adjusted odds ratio of accelerated aging (chronological age < biological age at 1 year) was 5.26 (95% confidence interval 1.51-18.28) in the D Ca B compared with the D Ca group. Accelerated aging in both groups was associated with younger age. In the D Ca B group, it was additionally associated with lower baseline homocysteine. Vitamin D Ca B and D Ca differentially affected epigenetic age markers, although the effect size appeared to be small after 1 year. B-vitamins effect in young subjects with low homocysteine requires further investigation. ClinicalTrials.gov ID: NCT02586181.
MeSH Terms
- Age Factors
- Aged
- Aged, 80 and over
- Aging
- Calcium Carbonate
- Cholecalciferol
- CpG Islands
- DNA Methylation
- Dietary Supplements
- Double-Blind Method
- Epigenesis, Genetic
- Female
- Folic Acid
- Germany
- Homocysteine
- Humans
- Male
- Middle Aged
- Time Factors
- Treatment Outcome
- Vitamin B 12
- Vitamin B 6
- Vitamin B Complex
Keywords
- Aging
- DNA-Methylation
- Epigenetics
- Supplementation
- Vitamins
Individual age estimation has the potential to provide key information that could enhance and extend DNA intelligence tools. Following predictive tests for externally visible characteristics developed in recent years, prediction of age could guide police investigations and improve the assessment of age-related phenotype expression patterns such as hair colour changes and early onset of male pattern baldness. DNA methylation at CpG positions has emerged as the most promising DNA tests to ascertain the individual age of the donor of a biological contact trace. Although different methodologies are available to detect DNA methylation, EpiTYPER technology (Agena Bioscience, formerly Sequenom) provides useful characteristics that can be applied as a discovery tool in localized regions of the genome. In our study, a total of twenty-two candidate genomic regions, selected from the assessment of publically available data from the Illumina HumanMethylation 450 BeadChip, had a total of 177 CpG sites with informative methylation patterns that were subsequently investigated in detail. From the methylation analyses made, a novel age prediction model based on a multivariate quantile regression analysis was built using the seven highest age-correlated loci of ELOVL2, ASPA, PDE4C, FHL2, CCDC102B, C1orf132 and chr16:85395429. The detected methylation levels in these loci provide a median absolute age prediction error of ±3.07years and a percentage of prediction error relative to the age of 6.3%. We report the predictive performance of the developed model using cross validation of a carefully age-graded training set of 725 European individuals and a test set of 52 monozygotic twin pairs. The multivariate quantile regression age predictor, using the CpG sites selected in this study, has been placed in the open-access Snipper forensic classification website.
MeSH Terms
- Adolescent
- Adult
- Aged
- Aged, 80 and over
- Aging
- CpG Islands
- DNA Methylation
- Female
- Genetic Loci
- Genetic Markers
- Humans
- Male
- Mass Spectrometry
- Middle Aged
- Multivariate Analysis
- Polymerase Chain Reaction
- Software
- Twins, Monozygotic
- Young Adult
Keywords
- Agena Bioscience EpiTYPER
- CpG sites
- DNA methylation
- Forensic age estimation
- Illumina HumanMethylation 450K
- Multivariate quantile regression
Aging is reflected by highly reproducible DNA methylation (DNAm) changes that open new perspectives for estimation of chronological age in legal medicine. DNA can be harvested non-invasively from cells at the inside of a person's cheek using buccal swabs - but these specimens resemble heterogeneous mixtures of buccal epithelial cells and leukocytes with different epigenetic makeup. In this study, we have trained an age predictor based on three age-associated CpG sites (associated with the genesPDE4C, ASPA, and ITGA2B) for swab samples to reach a mean absolute deviation (MAD) between predicted and chronological age of 4.3 years in a training set and of 7.03 years in a validation set. Subsequently, the composition of buccal epithelial cells versus leukocytes was estimated by two additional CpGs (associated with the genes CD6 and SERPINB5). Results of this "Buccal-Cell-Signature" correlated with cell counts in cytological stains (R2 = 0.94). Combination of cell type-specific and age-associated CpGs into one multivariate model enabled age predictions with MADs of 5.09 years and 5.12 years in two independent validation sets. Our results demonstrate that the cellular composition in buccal swab samples can be determined by DNAm at two cell type-specific CpGs to improve epigenetic age predictions.
MeSH Terms
- Adolescent
- Adult
- Aged
- Aged, 80 and over
- Aging
- Amidohydrolases
- Child
- Child, Preschool
- CpG Islands
- Cyclic Nucleotide Phosphodiesterases, Type 4
- DNA
- DNA Methylation
- Female
- Humans
- Infant
- Integrin alpha2
- Male
- Middle Aged
- Young Adult
Keywords
- aging
- cell composition
- epigenetic
- epithelial cells
- methylation
- predictor
- swab
Gene methylation is an age-related dynamic process that influences diseases. Premature aging and disturbed methylation are components of Down syndrome (DS). We studied blood biomarkers and DNA methylation (DNAm) of three CpG sites (ASPA, ITGA2B, and PDE4C) in 60 elderly subjects (mean age = 68 years), 31 subjects with DS (12.1 years) and 44 controls (12.8 years). Plasma concentrations of amyloid beta (Aβ) 1-42 and biomarkers of methylation were measured in the young groups. Subjects with DS had significantly higher concentrations of plasma S-adenosylhomocysteine (SAH) and Aβ and reduced S-adenosylmethionine/SAH ratio compared with the controls. Methylations (%) of ASPA and ITGA2B were lower in DS [mean difference; 95 % confidence intervals = -2.2 (-4.5, 0.1) for ASPA and -5.0 (-8.9, -1.1) for ITGA2B]. Methylation of PDE4C did not differ between the groups. The sum of z-scores for methylations of ASPA and ITGA2B, both of which declined with age, was significantly lower in DS [-1.01 (-1.93, -0.20), p = 0.017]. Subjects with DS were found to be 3.1 (1.5-4.6) years older than their predicted age based on a regression model of the controls. Elevated SAH levels predicted lower DNAm of ASPA and ITGA2B in stepwise regression analysis. Therefore, methylation of three CpGs combined with plasma Aβ has shown a 3-year accelerated aging in subjects with DS at the age of 12 years. Disorders in the methylation cycle explained pathoepigenetic modifications in subjects with DS. The influence of modifications in the methylation cycle on epigenetic markers of aging warrants further investigations.
MeSH Terms
- Aged
- Aging
- Amyloid beta-Peptides
- Biomarkers
- Child
- DNA Methylation
- Down Syndrome
- Epigenomics
- Humans
Keywords
- Aging
- Amyloid beta
- DNA methylation
- Epigenomics
- Trisomy 21
Age prediction of an individual based on biological traces remained in a crime scene is of ultimate importance for criminal investigation. Growing evidence indicates that some CpG sites may have age-related methylation changes and thus may be a promising tool for age prediction. In this study, we utilized the pyrosequencing approach to screen age-related CpG (AR-CpG) sites for age prediction. Five AR-CpGs were identified as age-related markers from thirty-eight candidates, among which three CpG sites, ITGA2B_1, NPTX2_3, and NPTX2_4 were never reported in previous studies. We fit a linear regression model for age prediction based on methylation assay for 89 blood samples from donors aged 9-75 years old. The model included four AR-CpG markers in three gene fragments ASPA, ITGA2B and NPTX2 and enabled the age prediction with R(2)=0.819. The mean absolute deviation (MAD) from chronological age of the model was 7.870. We validated the linear regression model with a validation set of 40 blood samples, and the prediction MAD was 7.986. There was no statistically significant difference in age prediction between 20 pairs of blood samples and bloodstains. Six pairs of fresh and old bloodstains were analyzed using our assay. The obtained results showed the assay still performed an effective prediction on bloodstains after four-month storage in room conditions. This study indicates that our DNA methylation assay is a reliable and effective method for age prediction for forensic purposes.
MeSH Terms
- Adolescent
- Adult
- Aged
- Aging
- Biomarkers
- Blood Stains
- Child
- CpG Islands
- DNA
- DNA Methylation
- Female
- Forensic Genetics
- Humans
- Linear Models
- Male
- Middle Aged
- Predictive Value of Tests
- Sequence Analysis, DNA
- Young Adult
Keywords
- Age prediction
- DNA methylation
- Forensic science
- Human blood
- Human bloodstain
- Pyrosequencing
Human aging is associated with DNA methylation changes at specific sites in the genome. These epigenetic modifications may be used to track donor age for forensic analysis or to estimate biological age. We perform a comprehensive analysis of methylation profiles to narrow down 102 age-related CpG sites in blood. We demonstrate that most of these age-associated methylation changes are reversed in induced pluripotent stem cells (iPSCs). Methylation levels at three age-related CpGs--located in the genes ITGA2B, ASPA and PDE4C--were subsequently analyzed by bisulfite pyrosequencing of 151 blood samples. This epigenetic aging signature facilitates age predictions with a mean absolute deviation from chronological age of less than 5 years. This precision is higher than age predictions based on telomere length. Variation of age predictions correlates moderately with clinical and lifestyle parameters supporting the notion that age-associated methylation changes are associated more with biological age than with chronological age. Furthermore, patients with acquired aplastic anemia or dyskeratosis congenita--two diseases associated with progressive bone marrow failure and severe telomere attrition--are predicted to be prematurely aged. Our epigenetic aging signature provides a simple biomarker to estimate the state of aging in blood. Age-associated DNA methylation changes are counteracted in iPSCs. On the other hand, over-estimation of chronological age in bone marrow failure syndromes is indicative for exhaustion of the hematopoietic cell pool. Thus, epigenetic changes upon aging seem to reflect biological aging of blood.
MeSH Terms
- Aging
- Amidohydrolases
- Blood Cells
- Cellular Senescence
- CpG Islands
- Cyclic Nucleotide Phosphodiesterases, Type 4
- DNA Methylation
- Epigenesis, Genetic
- Genome, Human
- Humans
- Induced Pluripotent Stem Cells
- Integrin alpha2
Canavan disease (CD) is an autosomal-recessive neurodegenerative disorder caused by inactivation of the enzyme aspartoacylase (ASPA, EC 3.5.1.15) due to mutations. ASPA releases acetate by deacetylation of N-acetylaspartate (NAA), a highly abundant amino acid derivative in the central nervous system. CD results in spongiform degeneration of the brain and severe psychomotor retardation, and the affected children usually die by the age of 10. The pathogenesis of CD remains a matter of inquiry. Our hypothesis is that ASPA actively participates in myelin synthesis by providing NAA-derived acetate for acetyl CoA synthesis, which in turn is used for synthesis of the lipid portion of myelin. Consequently, CD results from defective myelin synthesis due to a deficiency in the supply of the NAA-derived acetate. The demonstration of the selective localization of ASPA in oligodendrocytes in the central nervous system (CNS) is consistent with the acetate deficiency hypothesis of CD. We have tested this hypothesis by determining acetate levels and studying myelin lipid synthesis in the ASPA gene knockout model of CD, and the results provided the first direct evidence in support of this hypothesis. Acetate supplementation therapy is proposed as a simple and inexpensive therapeutic approach to this fatal disease, and progress in our preclinical efforts toward this goal is presented.
MeSH Terms
- Aging
- Animals
- Aspartic Acid
- Canavan Disease
- Central Nervous System
- Humans
- Mice
- Mice, Knockout
- Myelin Basic Protein
Canavan disease, an autosomal-recessive neurogenetic disorder, is caused by mutations in aspartoacylase, an enzyme that deacetylates N-acetylaspartate to generate free acetate in the brain. Earlier studies have shown that aspartoacylase is primarily restricted to myelin synthesizing cells (oligodendroglia) in the CNS. These findings have led us to investigate the developmental expression of aspartoacylase gene in the rat brain in an attempt to shed more light on the role of this enzyme in myelination. In situ hybridization using a 35S riboprobe based on murine aspartoacylase cDNA was used in this study. The probe hybridized mostly to the white matter tracts with different densities depending on the age of the animal and region of the brain examined. Little or no hybridization signals were detected in the 1-day-old rats, whereas the signal was clearly detectable in most of the white matter regions of the CNS in the 11-day-old rats. The signal density markedly increased at postnatal day 17, the peak of myelination. Thereafter, the hybridization signals decreased somewhat but still could be observed in the adult animals. Thus, the developmental expression pattern of aspartoacylase gene in the postnatal brain closely parallels myelination in the CNS. In the CNS, the hybridization signal of ASPA appeared to be restricted primarily to oligodendrocytes, the primary myelin synthesizing cell type in the CNS. However, the signal was not detectable in rat sciatic nerve (Schwann cells) of the peripheral nervous system. These findings indicate that the role of N-acetylaspartate in myelin synthesis is restricted to the CNS. Furthermore, they provide additional support for the acetate deficiency hypothesis of Canavan disease and also make a stronger case for acetate supplementation as an immediate and inexpensive therapy for Canavan disease.
MeSH Terms
- Aging
- Amidohydrolases
- Animals
- Animals, Newborn
- Brain
- Gene Expression Regulation, Developmental
- Gene Expression Regulation, Enzymologic
- In Situ Hybridization
- Male
- Myelin Sheath
- Oligodendroglia
- RNA, Messenger
- Rats
- Rats, Sprague-Dawley
- Transcription, Genetic