Differentially methylated gene patterns between age-matched sarcopenic and non-sarcopenic women

Area of Science:

• Epigenetics
• Gerontology
• Molecular Biology

Background:

• Sarcopenia, characterized by age-related muscle mass and strength decline, has poorly understood epigenetic mechanisms.
• DNA methylation is a key epigenetic factor potentially involved in sarcopenia pathogenesis.
• Investigating DNA methylation in blood offers a non-invasive approach to study sarcopenia's molecular basis.

Purpose of the Study:

• To explore DNA methylation differences in blood between sarcopenic and non-sarcopenic older women.
• To identify specific differentially methylated CpG sites (dmCpGs) and related genes associated with sarcopenia.
• To analyze the functional implications of identified methylation changes in sarcopenia.

Main Methods:

• Selected 24 sarcopenic and 24 age-matched non-sarcopenic Caucasian women (65-80 years).
• Analyzed whole blood DNA methylation using Infinium MethylationEPIC BeadChip arrays.
• Identified differentially methylated CpG sites (dmCpGs) and performed gene ontology and pathway enrichment analysis.

Main Results:

• No global methylation difference, but 6258 dmCpGs showed significantly lower average methylation in sarcopenic individuals.
• Sarcopenic group exhibited higher methylation in promoter regions (TSS200) and lower methylation in gene bodies and 3'UTRs.
• dmCpG-related pathways included muscle function, actin cytoskeleton regulation, and energy metabolism; several genes showed age-related methylation patterns.

Conclusions:

• Identified specific DNA methylation differences in blood linked to sarcopenia in older women.
• These epigenetic alterations suggest changes in gene expression and pathway functions contributing to muscle decline.
• Findings provide insights into the epigenetic mechanisms underlying sarcopenia.