Project description:The mechanisms of aging-related oocyte aneuploidy remain elusive. Hi-C and SMART-seq revealed aging-related decreases in chromosome condensation, particularly for genomic regions proximal to the centromeres, accompanied with disrupted meiosis-associated gene expression in metaphase I (MI) aged oocytes. Further transcriptomic analysis showed that oocyte meiotic maturation was correlated with robust increases in mevalonate (MVA) pathway gene expression in young oocyte-surrounding granulosa cells (GCs), which was largely downregulated in aged GCs. Inhibtion of MVA metabolism in GCs by statins resulted in marked meiotic defects and aneuploidy in young cumulus-oocyte complexes (COCs). Conversely, supplementation with the MVA isoprenoid geranylgeraniol ameliorated meiotic defects and aneuploidy in aged COCs. Meanwhile, geranylgeraniol also activated LHR/EGF signaling in aged GCs and then enhanced the meiosis-associated gene expression in oocytes. Generally, the MVA pathway in GCs is a critical regulator of meiotic maturation and euploidy in oocytes.
Project description:The mechanisms of oocyte meiotic defects and low competence during ovarian aging remains elusive for decades. Using Hi-C (genome-wide chromatin conformation capture) and Smart RNA-seq of oocytes from 6- weeks or 10- months aged ovaries, the abnormal loose chromatin structures and disturbing expression of meiosis associated genes at metaphase I phase were disclosed. Furthermore, the transcriptomic landscape of granulosa cells (GCs) surrounding oocytes from young and aged ovaries reveled that oocyte meiotic maturation was accompanied with a robust increased expression of genes involved with the mevalonate (MVA) pathway in GCs from young ovaries but these genes expression was not upregulated to counterpart level in GCs from aged ovaries.The inhibitor of MVA pathway of GCs, Statins significantly decreased polar body extrusion rate and increased the rate of irregularly assembled spindles and misaligned chromosomes remarkably in oocytes of culumus-oocyte complex (COCs) from young ovaries . Correspondingly, the activitor of MVA pathway of GCs, Geranylgeraniol ameliorated ovarian reserve and reduced meiotic defects in oocytes of COCs from aged ovaries. Mechanistically, MVA pathway activation in GCs culminated oocyte meiotic maturation by upregulating EGF signaling via LH receptor on GCs surrounding oocytes. Together, MVA pathway is a promising therapeutic target for prompting quality of oocytes from aged ovaries.
Project description:The mechanisms of oocyte meiotic defects and low competence during ovarian aging remains elusive for decades. Using Hi-C (genome-wide chromatin conformation capture) and Smart RNA-seq of oocytes from 6- weeks or 10- months aged ovaries, the abnormal loose chromatin structures and disturbing expression of meiosis associated genes at metaphase I phase were disclosed. Furthermore, the transcriptomic landscape of granulosa cells (GCs) surrounding oocytes from young and aged ovaries reveled that oocyte meiotic maturation was accompanied with a robust increased expression of genes involved with the mevalonate (MVA) pathway in GCs from young ovaries but these genes expression was not upregulated to counterpart level in GCs from aged ovaries.The inhibitor of MVA pathway of GCs, Statins significantly decreased polar body extrusion rate and increased the rate of irregularly assembled spindles and misaligned chromosomes remarkably in oocytes of culumus-oocyte complex (COCs) from young ovaries . Correspondingly, the activitor of MVA pathway of GCs, Geranylgeraniol ameliorated ovarian reserve and reduced meiotic defects in oocytes of COCs from aged ovaries. Mechanistically, MVA pathway activation in GCs culminated oocyte meiotic maturation by upregulating EGF signaling via LH receptor on GCs surrounding oocytes. Together, MVA pathway is a promising therapeutic target for prompting quality of oocytes from aged ovaries.
Project description:The mechanisms of oocyte meiotic defects and low competence during ovarian aging remains elusive for decades. Using Hi-C (genome-wide chromatin conformation capture) and Smart RNA-seq of oocytes from 6- weeks or 10- months aged ovaries, the abnormal loose chromatin structures and disturbing expression of meiosis associated genes at metaphase I phase were disclosed. Furthermore, the transcriptomic landscape of granulosa cells (GCs) surrounding oocytes from young and aged ovaries reveled that oocyte meiotic maturation was accompanied with a robust increased expression of genes involved with the mevalonate (MVA) pathway in GCs from young ovaries but these genes expression was not upregulated to counterpart level in GCs from aged ovaries.The inhibitor of MVA pathway of GCs, Statins significantly decreased polar body extrusion rate and increased the rate of irregularly assembled spindles and misaligned chromosomes remarkably in oocytes of culumus-oocyte complex (COCs) from young ovaries . Correspondingly, the activitor of MVA pathway of GCs, Geranylgeraniol ameliorated ovarian reserve and reduced meiotic defects in oocytes of COCs from aged ovaries. Mechanistically, MVA pathway activation in GCs culminated oocyte meiotic maturation by upregulating EGF signaling via LH receptor on GCs surrounding oocytes. Together, MVA pathway is a promising therapeutic target for prompting quality of oocytes from aged ovaries.