Expression profiling of MRC5 senescent fibroblasts

Microarrays analysis identifies WNT16in senescent fibroblasts. To identify genes expressed in replicative senescence, microarray experiments were conducted in which we compared the RNA expression profile of young MRC5 fibroblasts at population doubling 28 (PDL28) and replicative senescent MRC5 fibroblasts at PDL63. In total, 177 gene probes were upregulated and 338 gene probes were downregulated in senescent versus young MRC5 fibroblasts. Genes were classified based on mapping to KEGG pathways. Upregulated genes were enriched in three KEGG pathways, the Wingless-type MMTV integration site (WNT) signaling pathway (WNT16, PLCB4, CCND2, SFRP1, WNT5B, RAC2), cytokine-cytokine receptor interaction (TNFRSF10D, TNFRSF10B, TNFRSF10C, IL1R2, IL18, VEGFC), and the p53 signaling pathway (CDKN1A, TNFRSF10B, PERP, STEAP3, ZMAT3). Repressed genes were enriched in three KEGG pathways, cell cycle (PKMYT1, CDC7, CCNE2, MCM4, BUB1, CDC25A, CDKN1B, MCM6, PLK1, CDKN2C, CCNB2, MCM3, BUB1B, CCNA2, CDC2), cytokine-cytokine receptor interaction (KITLG, IL11, TNFSF4, CCL2, PDGFRA, TNFRSF11B, TGFBR1, IL1R1, TNFRSF19), and DNA replication (POLE, RFC2, MCM4, RNASEH2B, POLA1, DNA2, MCM6, PRIM1, RFC4, MCM3). Along with p53 transcriptional targets (CDKN1A, PERP, WIG1), genes encoding secreted factors (WNT16, MMP10, MMP3) were among the most strongly increased in senescent cells. Six arrays were hybridized with complex probes consisting of RNA isolated from MRC5 fibroblasts at population doubling 63 (undergoing replicative senescence) and RNA isolated from MRC5 fibroblats at population doubling 28 (young). The six arrays correspond to three biological replicates, each with a dye-swap technical replicate.