Gene expresion analysis among young mouse embryos, aging mouse embryos and aging mouse embryos suppressed their CXCL5-CXCR2 signaling.

CXCL5-CXCR2 signailing is known as senescence-associated secretory phenotype (SASP) factor to promote cellular senescense in diverse cells. We identified CXCL5 as a SASP factor in human and mouse embryos and suppression of CXCL5-CXCR2 signaling during embryo culture improved pregnancy success in aging mice. Here, we perfomed microarray analysis using mouse blastocysts for comparing gene expression pattarns among young mouse embryos, aging mouse embryos and aging mouse embryos suppressed their CXCL5-CXCR2 signaling. As a results, gene expression pattern of CXCL5-CXCR2 signaling-suppressed aging blastocysts was closer to that of the young blastocysts as compared with aging blastocysts. In addition, cell proliferation-related pathways, such as “PI3K signaling pathway” and “RAS signaling pathway” were significantly enriched in CXCL5-suppressed blastocysts. Two age group of female ICR mice (young; 3-6 weeks of age and aging; 43-53 weeks of age) were purchased from SLC Japan (Shizuoka, Japan) and maintained in a standard laboratory animal facility with controlled environment (temperature; 22 ℃, humidity; 55-65 % and light cycle; 12 hours interval). For embryo collection, super-ovulated mice were mated with male mice immediately after hCG treatment. At 18 hours after hCG injection, zygotes were obtained by flashing the oviducts of mated mice. Collected zygotes were cultured in 30 μl drops of KSOM medium without or with anti-CXCL5 neutralizing antibody (10 μg/ml) and CXCR2 selective antagonist (10nM) for suppressing CXCL5-CXCR2 signal. After 96 hours culture, blastocysts were collected for RNA extraction and microarray analysis.