Project description:Background: Age-related physiological, biochemical and functional changes in mammalian skeletal muscle have been shown to begin at the mid-point of the lifespan. However, the underlying changes in DNA methylation that occur during this turning point of the muscle aging process have not been clarified. To explore age-related genomic methylation changes in skeletal muscle, we employed young (0.5 years old) and middle-aged (7 years old) pigs as models to survey genome-wide DNA methylation in the longissimus dorsi muscle using a methylated DNA immunoprecipitation sequencing approach. Results: We observed a tendency toward a global loss of DNA methylation in the gene-body region of the skeletal muscle of the middle-aged pigs compared with the young group. We determined the genome-wide gene expression pattern in the longissimus dorsi muscle using microarray analysis and performed a correlation analysis using DMR (differentially methylated region)-mRNA pairs, and we found a significant negative correlation between the changes in methylation levels within gene bodies and gene expression. Furthermore, we identified numerous genes that show age-related methylation changes that are potentially involved in the aging process. The methylation status of these genes was confirmed using bisulfite sequencing PCR. The genes that exhibited a hypomethylated gene body in middle-aged pigs were over-represented in various proteolysis and protein catabolic processes, suggesting an important role for these genes in age-related muscle atrophy. In addition, genes associated with tumorigenesis exhibited aged-related differences in methylation and expression levels, suggesting an increased risk of disease associated with increased age. Conclusions: This study provides a comprehensive analysis of genome-wide DNA methylation patterns in aging pig skeletal muscle. Our findings will serve as a valuable resource in aging studies, promoting the pig as a model organism for human aging research and accelerating the development of comparative animal models in aging research. We collected the longissimus dorsi muscles tissue from Jinhua pigs which aged 0.5 year and seven years and study the genome-wide DNA methylation difference between the two age periods.
Project description:Background: Age-related physiological, biochemical and functional changes in mammalian skeletal muscle have been shown to begin at the mid-point of the lifespan. However, the underlying changes in DNA methylation that occur during this turning point of the muscle aging process have not been clarified. To explore age-related genomic methylation changes in skeletal muscle, we employed young (0.5 years old) and middle-aged (7 years old) pigs as models to survey genome-wide DNA methylation in the longissimus dorsi muscle using a methylated DNA immunoprecipitation sequencing approach. Results: We observed a tendency toward a global loss of DNA methylation in the gene-body region of the skeletal muscle of the middle-aged pigs compared with the young group. We determined the genome-wide gene expression pattern in the longissimus dorsi muscle using microarray analysis and performed a correlation analysis using DMR (differentially methylated region)-mRNA pairs, and we found a significant negative correlation between the changes in methylation levels within gene bodies and gene expression. Furthermore, we identified numerous genes that show age-related methylation changes that are potentially involved in the aging process. The methylation status of these genes was confirmed using bisulfite sequencing PCR. The genes that exhibited a hypomethylated gene body in middle-aged pigs were over-represented in various proteolysis and protein catabolic processes, suggesting an important role for these genes in age-related muscle atrophy. In addition, genes associated with tumorigenesis exhibited aged-related differences in methylation and expression levels, suggesting an increased risk of disease associated with increased age. Conclusions: This study provides a comprehensive analysis of genome-wide DNA methylation patterns in aging pig skeletal muscle. Our findings will serve as a valuable resource in aging studies, promoting the pig as a model organism for human aging research and accelerating the development of comparative animal models in aging research.
Project description:Background Age-related physiological, biochemical and functional changes in mammalian skeletal muscle have been shown to begin at the mid-point of the lifespan. However, the underlying changes in DNA methylation that occur during this turning point of the muscle aging process have not been clarified. To explore age-related genomic methylation changes in skeletal muscle, we employed young (0.5 years old) and middle-aged (7 years old) pigs as models to survey genome-wide DNA methylation in the longissimus dorsi muscle using a methylated DNA immunoprecipitation sequencing approach. Results We observed a tendency toward a global loss of DNA methylation in the gene-body region of the skeletal muscle of the middle-aged pigs compared with the young group. We determined the genome-wide gene expression pattern in the longissimus dorsi muscle using microarray analysis and performed a correlation analysis using DMR (differentially methylated region)-mRNA pairs, and we found a significant negative correlation between the changes in methylation levels within gene bodies and gene expression. Furthermore, we identified numerous genes that show age-related methylation changes that are potentially involved in the aging process. The methylation status of these genes was confirmed using bisulfite sequencing PCR. The genes that exhibited a hypomethylated gene body in middle-aged pigs were over-represented in various proteolysis and protein catabolic processes, suggesting an important role for these genes in age-related muscle atrophy. In addition, genes associated with tumorigenesis exhibited aged-related differences in methylation and expression levels, suggesting an increased risk of disease associated with increased age. Conclusions This study provides a comprehensive analysis of genome-wide DNA methylation patterns in aging pig skeletal muscle. Our findings will serve as a valuable resource in aging studies, promoting the pig as a model organism for human aging research and accelerating the development of comparative animal models in aging research.
Project description:A decline in skeletal muscle mass and function with aging is well recognized, but remains poorly characterized at the molecular level. Here we report for the first time a genome-wide study of DNA methylation dynamics in skeletal muscle of healthy male individuals during normal human aging. We predominantly observed hypermethylation throughout the genome within the aged group as compared to the young subjects. Differentially methylated CpG (dmCpG) nucleotides tend to arise intragenically, and are underrepresented in promoters and are overrepresented in the middle and 3’ end of genes. The intragenic methylation changes are over represented in genes which guide the formation of the junction of the motor neuron and myofibers. We report a low level of correlation between previous gene expression studies of aged muscle with our current analysis of DNA methylation status. For those genes that had both changes in methylation and gene expression with age, we observed a reverse correlation, with the exception of intragenic hypermethylated genes, that were correlated with increased gene expression. We argue that a minimal number of dmCpG sites or select sites are required to be altered in order to correlate with gene expression changes. Finally, we identified 500 dmCpG biomarkers that perform well in a prediction of human biological age within our cohorts. Our findings highlight epigenetic links between aging post-mitotic skeletal muscle and DNA methylation. 48 experimental samples (24 young and 24 older individuals) were used overall. There were 4 replicates per group.
Project description:A decline in skeletal muscle mass and function with aging is well recognized, but remains poorly characterized at the molecular level. Here we report for the first time a genome-wide study of DNA methylation dynamics in skeletal muscle of healthy male individuals during normal human aging. We predominantly observed hypermethylation throughout the genome within the aged group as compared to the young subjects. Differentially methylated CpG (dmCpG) nucleotides tend to arise intragenically, and are underrepresented in promoters and are overrepresented in the middle and 3’ end of genes. The intragenic methylation changes are over represented in genes which guide the formation of the junction of the motor neuron and myofibers. We report a low level of correlation between previous gene expression studies of aged muscle with our current analysis of DNA methylation status. For those genes that had both changes in methylation and gene expression with age, we observed a reverse correlation, with the exception of intragenic hypermethylated genes, that were correlated with increased gene expression. We argue that a minimal number of dmCpG sites or select sites are required to be altered in order to correlate with gene expression changes. Finally, we identified 500 dmCpG biomarkers that perform well in a prediction of human biological age within our cohorts. Our findings highlight epigenetic links between aging post-mitotic skeletal muscle and DNA methylation.
Project description:DNA methylation has been considered to play an important role in myogenic differentiation. In terminal differentiation of myoblasts, a chronological pattern of DNA methylation changes has been poorly understood. Using Infinium HumanMethylation450 BeadChips, we obtained and evaluated the genome-wide DNA methylation profiles of human myoblast differentiation in vitro. DNA methylation profiles of human myoblasts (day1, day3, day8, day15), human mesenchymal stem cells (1 sample) and human skeletal muscle tissues (2 samples) were obtained using Infinium HumanMethylation450 BeadChips (Illumina).
Project description:Genome-wide DNA methylation profiling of healthy young men following a control and high-fat overfeeding diet using Illumina's Infinium 27k Human DNA methylation Beadchip v. 1.2. DNA methylation profiles were obtained for 27,578 CpG sites in human skeletal muscle.
Project description:Age-related methylation changes have been identified in various tissues and organisms, yet the underlying DNA methylation alterations in muscle aging process have not been clearly clarified. Whilst, many studies revealed that the structural and functional changes in skeletal muscle during aging process started from the mid-point of lifespan. In this study, we used pigs aged 0.5 year and 7 years, representing young and middle-aged periods. Using methylated DNA immunoprecipitation sequencing, we performed comprehensive genome-wide DNA methylation profiling for longissimus dorsi muscle in young and middle-aged pigs. We found more genes showed differently methylated in genebody. In details, 185 human ortholog genes contained DMRs that located in the promoter region, while 657 genes and 1063 genes with DMRs in gene body showed hypermethylation and hypomethylation in MA pigs, respectively. From the gene enrichment analysis, genebody hypermethylated genes showed significant enrichment for several molecular functions such as M-bM-^@M-^XGTPase regulator activityM-bM-^@M-^Y, M-bM-^@M-^XATP bindingM-bM-^@M-^Y and M-bM-^@M-^Xprotein kinase activityM-bM-^@M-^Y. Notably, genebody hypomethylated genes showed significant enrichment for various proteolysis and protein catabolic process. However, genes with DMR in their promoter region were not significantly enriched in any biology process. Proteolysis-associated genes, such as FOXO3 and FGFR1, showed different genebody methylation and mRNA expression level in two age groups, which may contribute to muscle atrophy during aging. Especially, other tumorigenesis-associated genes including GPI and GRB2, exhibited increasing mRNA level in middle-aged pigs, suggesting the possible higher risk of having cancer in human middle-aged period. Our results will serve as a valuable resource in aging studies, promote pig as a model organism for human aging research and accelerate the considerable development of comparative animal models in aging research. We collected the longissimus dorsi muscles tissue from Jinhua pigs which aged 0.5 year and seven years and study the genome-wide DNA methylation difference and the genome-wide gene expression profile between the two age periods. This submission represents transcriptome component of study.
Project description:Genome-wide DNA methylation profiling of young men born with low birth weight following a control and high-fat overfeeding diet using Illumina's Infinium 27k Human DNA methylation Beadchip v. 1.2. DNA methylation profiles were obtained for 27,578 CpG sites in human skeletal muscle.