Transcriptome analysis of aging muscle progenitors (human myoblasts)

Although sarcopenia is evident from the fifth decade, mechanisms leading to this phenomenon start earlier, emphasizing the importance of defining biomarkers related to the onset of muscle weakness. To this aim, a transcriptome analysis will be performed on muscle cell cultures (myoblasts) obtained from adult donors of different ages. Any biomarkers identified by this analysis will be confirmed by western blot and immunostatining. We will then assess the role of those biomarkers in muscle aging. Human myoblasts were extracted from the quadriceps of young (15-20 years old) and elderly (>70 years old) healthy subjects . The muscle cell population has been sorted using CD56 MACS beads. The myogenicity and the life span analysis of each muscle cell extract have been determined. We analysed the transcriptome (mRNA profiles) of the same cells at day 1 (baseline) and day 3 of differentiation (n=4 for the baseline (day1 ) group, and n=3 per day 3 group; Young and aged adult). This should allow us to identify which pathway(s) are disregulated with aging, and help to answer the fundamental question: whether muscle stem cells progressively loose their potential to self re-new during ageing. We also, treated old myoblasts with 5-AZA to demethylate the DNA - and did microarray expression profiling before and after treatment. We used HumanHT-12 v4 Expression BeadChips for the whole transcriptome analysis.