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Developmental and age-related changes in apolipoprotein B mRNA editing in mice
K Higuchi1, K Kitagawa, K Kogishi
1Department of Senescence Biology, Kyoto University, Japan.
Journal of Lipid Research
|December 1, 1992
Summary
Apolipoprotein B (apoB) mRNA editing decreases with age in mouse liver, impacting serum protein levels. This RNA editing process is crucial for lipoprotein biogenesis, especially in aging mammals.
Area of Science:
- Biochemistry
- Molecular Biology
- Genetics
Background:
- Apolipoprotein B (apoB) mRNA undergoes post-transcriptional editing (C to U), converting glutamine to a stop codon and producing apoB-48.
- This editing occurs in mammalian liver and intestine, influencing apoB protein isoforms.
Purpose of the Study:
- To investigate developmental and age-related changes in apoB mRNA editing.
- To compare editing patterns in mouse strains with normal (SAM-R/1) and accelerated (SAM-P/1) aging.
Main Methods:
- Studied apoB mRNA editing in liver and small intestine of two mouse strains during development and aging.
- Analyzed serum apoB-100 and apoB-48 protein levels.
- Utilized reverse transcriptase-polymerase chain reaction (RT-PCR) to detect apoB expression in other tissues.
Main Results:
- Hepatic apoB mRNA editing decreased during development (80% to 30%) in both strains.
- Age-associated increases in unedited apoB-100 mRNA were observed in the liver of older mice (from 18 months in SAM-R/1, from 10 months in SAM-P/1).
- Serum apoB protein profiles mirrored hepatic mRNA editing changes; no significant age-related changes were found in the small intestine.
Conclusions:
- Hepatic apoB mRNA editing decreases with age, particularly in senescent mice.
- Age-related changes in apoB mRNA editing correlate with alterations in serum apoB protein levels.
- RNA editing is a potential regulatory mechanism for lipoprotein biogenesis during development and aging.
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