Abstract
Oculopharyngeal muscular dystrophy (OPMD) is caused by trinucleotide repeat expansion mutations in Poly(A)binding protein 1 (PABPN1). PABPN1 is a regulator of mRNA stability and is ubiquitously expressed. Here we investigatedhow symptoms in OPMD initiate only at midlife and why a subset of skeletal muscles is predominantly affected. Genome-wide RNA expression profiles from Vastus lateralis muscles human carriers of expanded-PABPN1 at pre-symptomatic andsymptomatic stages were compared with healthy controls. Major expression changes were found to be associated with age rather than with expression of expanded-PABPN1, instead transcriptomes of OPMD and elderly muscles weresignificantly similar (P<0.05). Using k-means clustering we identified age-dependent trends in both OPMD and controls, buttrends were often accelerated in OPMD. We report an age-regulated decline in PABPN1 levels in Vastus lateralis musclesfrom the fifth decade. In concurrence with severe muscle degeneration in OPMD, the decline in PABPN1 accelerated inOPMD and was specific to skeletal muscles. Reduced PABPN1 levels (30% to 60%) in muscle cells induced myogenic defectsand morphological signatures of cellular aging in proportion to PABPN1 expression levels. We suggest that PABPN1 level sregulate muscle cell aging and OPMD represents an accelerated muscle aging disorder.
Originalsprog | Engelsk |
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Tidsskrift | Aging |
Vol/bind | 5 |
Udgave nummer | 6 |
Sider (fra-til) | 412-26 |
Antal sider | 15 |
ISSN | 1945-4589 |
Status | Udgivet - jun. 2013 |