Identification of novel candidates for replicative senescence by functional proteomics

Abstract

To identify the underlying mechanisms that limit the mitotic potential of normal somatic cells, we have undertaken a high resolution differential proteomic analysis aimed at identifying proteins that were differentially expressed upon replicative senescence. Since replicative senescence in heterogenous primary fibroblast cultures is asynchronous, we analysed a group of conditionally immortalized rat embryo fibroblast cell lines that have previously been shown to undergo synchronous senescence upon inactivation of SV40 tsA58 T antigen. This identified 43 spots that were differentially expressed in these cell lines. Comparison of the identity of these features with those identified in a complimentary independent differential proteomic analysis of replicative senescence, directly in primary rat embryo fibroblasts upon serial passaging, identified nine features that were in common between the two studies even though they had been conducted entirely separately. None of these proteins have previously been recognized to be involved with replicative senescence. Thus, they represent novel starting points for elucidating the underlying mechanism that regulates the finite mitotic life span of somatic cells and how it can be overcome in cancer cells.

FGFR3 signaling induces a reversible senescence phenotype in chondrocytes similar to oncogene-induced premature senescence

“…2A, B). We next focused on other markers known to be upregulated (α-GLUCOSIDASE, APA1, CAVEOLIN 1/2, FKBP12, LAMIN A, NORE 1, RAL-A, SM22α and TIMP 1) or downregulated (ID 1/2) in senescent cells [22-27]. As determined by real-time RT-PCR, FGF2 upregulated α-Glucosidase , Caveolin1 , Lamin A , SM22α , Timp1 and Nore1 transcripts while the levels of Id2 decreased (Fig.…”

Kinetics of Senescence-associated Changes of Gene Expression in an Epithelial, Temperature-sensitive SV40 Large T Antigen Model

“…Both these studies used rat embryo fibroblasts and applied either a subtractionbased approach (10) or a two-dimensional gel approach (9). Our analysis differs in three major ways from the previous studies: (a) we used cells of epithelial origin (the other studies used fibroblasts); (b) we emphasized that we wanted to identify early changes in gene expression (compared with stationary senescent cells used in the other studies); and (c) we used a global gene expression approach to find senescence-associated genes.…”

“…Previous studies using temperaturesensitive SV40 T antigen to identify senescence candidate genes were performed after a 72-h heat inactivation in rat cells (9,10). At this time point, all cells were supposed to have entered senescence.…”

Understanding Dupuytren's Disease Using Systems Biology: A Move Away from Reductionism

“…DD fibroblasts may possess a higher potential for matrix and collagen production through passages than control fascia cells because the DD nodules and cords result from an uncontrolled proliferative cellular state. Differences in collagen, fibronectin proteins, matrix expression proteins, and even proteoglycans could be affected by cell passage because it is thought that at earlier passages all cells would mostly be proliferating while at later passages they would tend to become senescent (Benvenuti et al, 2002) or rather quiescent.…”