The Cbs Locus Affects the Expression of Senescence Markers and mtDNA Copy Number, but not Telomere Dynamics in Mice
Open Access
- 5 April 2020
- journal article
- research article
- Published by MDPI AG in International Journal of Molecular Sciences
- Vol. 21 (7), 2520
- https://doi.org/10.3390/ijms21072520
Abstract
Cystathionine β-synthase (CBS) is a housekeeping enzyme that catalyzes the first step of the homocysteine to cysteine transsulfuration pathway. Homozygous deletion of the Cbs gene in mice causes severe hyperhomocysteinemia and reduces life span. Here, we examined a possible involvement of senescence, mitochondrial DNA, and telomeres in the reduced life span of Cbs−/− mice. We found that senescence-related p21, Pai-1, Mcp1, and Il-6 mRNAs were significantly upregulated (2–10-fold) in liver, while p21 was upregulated in the brain of Cbs−/− mice (n = 20) compared with control Cbs+/− siblings (n = 20) in a sex- and age-dependent manner. Telomere length in blood (n = 80), liver (n = 40), and brain (n = 40) was not affected by the Cbs−/− genotype, but varied with sex and/or age. Levels of mitochondrial DNA tended to be reduced in livers, but not brains and blood, of Cbs−/− females (n = 20–40). The Cbs−/− genotype significantly reduced Tert mRNA expression in brain, but not liver, in a sex- and age-dependent manner. Multiple regression analysis showed that the senescence-related liver (but not brain) mRNAs and liver (but not brain or blood) mitochondrial DNA were associated with the Cbs genotype. In contrast, telomere length in blood, brain, and liver was not associated with the Cbs genotype or hyperhomocysteinemia, but was associated with sex (in brain and liver) and age (in brain and blood). Taken together, these findings suggest that the changes in senescence marker expression and mtDNA levels, but not telomere shortening, could account for the reduced life span of Cbs−/− mice.Funding Information
- Narodowe Centrum Nauki (2015/17/N/NZ3/03626, 2019/33/B/NZ4/01760, 2018/29/B/NZ4/0071, 2016/23/B/NZ5/00573)
- American Heart Association (17GRNT32910002)
This publication has 41 references indexed in Scilit:
- Cellular Senescence: Defining a Path ForwardCell, 2019
- Telomere shortening rate predicts species life spanProceedings of the National Academy of Sciences of the United States of America, 2019
- Chronological Aging Standard Curves of Telomere Length and Mitochondrial DNA Copy Number in Twelve Tissues of C57BL/6 Male MouseCells, 2019
- N‐Homocysteinylation impairs collagen cross‐linking in cystathionine β‐synthase‐deficient mice: a novel mechanism of connective tissue abnormalitiesThe FASEB Journal, 2016
- Cellular senescence in aging and age-related disease: from mechanisms to therapyNature Medicine, 2015
- Telomere Length in Epidemiology: A Biomarker of Aging, Age-Related Disease, Both, or Neither?Epidemiologic Reviews, 2013
- Mutations in cystathionine β‐synthase or methylenetetrahydrofolate reductase gene increaseN‐homocysteinylated protein levels in humansThe FASEB Journal, 2008
- New method for the determination of protein N-linked homocysteineAnalytical Biochemistry, 2008
- Mice deficient in cystathionine beta-synthase: animal models for mild and severe homocyst(e)inemia.Proceedings of the National Academy of Sciences of the United States of America, 1995
- The natural history of homocystinuria due to cystathionine beta-synthase deficiency.1985