Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2009-8-17
pubmed:abstractText
Advancing adult age is associated with a progressive decrease in skeletal muscle mass, strength and quality known as sarcopenia. The mechanisms underlying age-related skeletal muscle wasting and weakness are manifold and still remain to be fully elucidated. Despite the increasing evidence that the progress of muscle diseases leading to muscle atrophy/dystrophy may be related to defective RNA processing, no data on the morpho-functional features of skeletal muscle nuclei in sarcopenia are available at present. In this view, we have investigated, by combining morphometry and immunocytochemistry at light and electron microscopy, the fine structure of myonuclei as well as the distribution and amount of RNA processing factors in skeletal myofibres of biceps brachii and quadriceps femoris from adult and old rats. Results demonstrate that the myonuclei of aged type II fibres show an increased amount of condensed chromatin and lower amounts of phosphorylated polymerase II and DNA/RNA hybrid molecules, clearly indicating a decrease in pre-mRNA transcription rate compared to adult animals. In addition, myonuclei of aged fibres show decreased amounts of nucleoplasmic splicing factors and an accumulation of cleavage factors, polyadenilated RNA and perichromatin granules, suggesting a reduction in the processing and transport rate of premRNA. During ageing, it seems therefore that in rat myonuclei the entire production chain of mRNA, from synthesis to cytoplasmic export, is less efficient. This failure likely contributes to the reduced responsiveness of muscle cells to anabolic stimuli in the elderly.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1121-760X
pubmed:author
pubmed:issnType
Print
pubmed:volume
53
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
97-106
pubmed:meshHeading
pubmed-meshheading:19683983-Animals, pubmed-meshheading:19683983-Cell Aging, pubmed-meshheading:19683983-Cell Nucleolus, pubmed-meshheading:19683983-Cell Nucleus, pubmed-meshheading:19683983-Cleavage Stimulation Factor, pubmed-meshheading:19683983-DNA, pubmed-meshheading:19683983-Immunohistochemistry, pubmed-meshheading:19683983-In Situ Hybridization, pubmed-meshheading:19683983-Male, pubmed-meshheading:19683983-Muscle Fibers, Fast-Twitch, pubmed-meshheading:19683983-Muscle Fibers, Skeletal, pubmed-meshheading:19683983-Muscle Fibers, Slow-Twitch, pubmed-meshheading:19683983-Quadriceps Muscle, pubmed-meshheading:19683983-RNA, pubmed-meshheading:19683983-RNA, Messenger, pubmed-meshheading:19683983-RNA Polymerase II, pubmed-meshheading:19683983-RNA Processing, Post-Transcriptional, pubmed-meshheading:19683983-Rats, pubmed-meshheading:19683983-Rats, Wistar, pubmed-meshheading:19683983-snRNP Core Proteins
pubmed:articleTitle
Nuclei of aged myofibres undergo structural and functional changes suggesting impairment in RNA processing.
pubmed:affiliation
Dipartimento di Scienze Morfologico-Biomediche, Sezione di Anatomia e Istologia, University of Verona, Italy. manuela.malatesta@univr.it
pubmed:publicationType
Journal Article