Open AccessIncreased polyploidy in aortic vascular smooth muscle cells during aging is marked by cellular senescence
Author(s) -
Yang Dan,
McCrann Donald J.,
Nguyen Hao,
Hilaire Cynthia St.,
DePinho Ronald A.,
Jones Matthew R.,
Ravid Katya
Publication year - 2007
Publication title -
aging cell
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.103
H-Index - 140
eISSN - 1474-9726
pISSN - 1474-9718
DOI - 10.1111/j.1474-9726.2007.00274.x
Subject(s) - senescence , biology , polyploid , microbiology and biotechnology , vascular smooth muscle , phenotype , somatic cell , ploidy , cell , cell division , genetics , endocrinology , smooth muscle , gene
Summary We previously reported that the frequency of polyploid aortic vascular smooth muscle cells (VSMC) serves as a biomarker of aging. Cellular senescence of somatic cells is another marker of aging that is characterized by the inability to undergo cell division. Here, we examined whether polyploidy is associated with the development of cellular senescence in vivo . Analysis of aortic tissue preparations from young and old Brown Norway rats showed that expression of senescence markers such as p16 INK4a and senescence‐associated β‐galactosidase activity are detected primarily in the old tissues. VSMC from p16 INK4a knockout and control mice display similar levels of polyploid cells. Intriguingly, senescence markers are expressed in most, but not all, polyploid VSMC. Moreover, the polyploid cells exhibit limited proliferative capacity in comparison to their diploid counterparts. This study is the first to demonstrate in vivo that polyploid VSMC adopt a senescent phenotype.