Perichromatin fibrils accumulation in hepatocyte nuclei reveals alterations of pre-mRNA processing during aging.
We previously described an unusual accumulation of perichromatin fibrils (PF)-the in situ form of pre-mRNA transcription and early splicing-in hepatocyte nuclei of old rats. Here we have investigated, by immunoelectron microscopy, the nature of such PF, analyzing the presence of transcription, splicing and cleavage factors, polyadenylated RNA, and the incorporation of bromouridine in adult and old rats. Our observations revealed alterations in amount and/or distribution of pre-mRNA transcription, splicing and cleavage factors, as well as of polyadenylated RNA, together with lower bromouridine incorporation in newly transcribed RNA in the hepatocyte nucleoplasm of old rats. Therefore, our data indicate both a decrease in pre-mRNA transcription and a slow down of PF processing and transport during aging.
Malatesta
Manuela
M
1 Department of Morphological and Biomedical Sciences, Anatomy and Histology Section, University of Verona, Verona, Italy.
Biggiogera
Marco
M
Cisterna
Barbara
B
Balietti
Marta
M
Bertoni-Freddari
Carlo
C
Fattoretti
Patrizia
P
D000367:Age Factors; D000818:Animals; D015153:Blotting, Western; D002467:Cell Nucleus / Q000378:metabolism* / Q000648:ultrastructure; D016922:Cellular Senescence; D002843:Chromatin / Q000378:metabolism* / Q000648:ultrastructure; D005260:Female; D022781:Hepatocytes / Q000378:metabolism* / Q000648:ultrastructure; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D012322:RNA Precursors / Q000378:metabolism* / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar; D039221:mRNA Cleavage and Polyadenylation Factors / Q000378:metabolism
D002843:Chromatin; D012322:RNA Precursors; D039221:mRNA Cleavage and Polyadenylation Factors