Increased expression of Kifc1 and Kifc5b targeting endogenous-siRNA contribute to the age-related decline in oocyte quality
Ontology highlight
ABSTRACT: The oocyte is reliant on stores of endogenous mRNA transcripts in order to support their survival and integrity during a protracted period of dormancy as they await ovulation. Oocytes are however, known to experience an age-associated alteration in mRNA transcript abundance, a phenomenon that contributes to reduced developmental potential. Here we have investigated whether the expression profile of small non-coding RNAs (sncRNAs) is similarly altered in aged mouse oocytes. The application of high throughput sequencing revealed substantial changes in the global sncRNA profile of germinal vesicle stage oocytes from young (4-6 weeks) and aged mice (14-16 months). Among these changes, we identified 160 endo-siRNA and ten microRNAs that differentially accumulated within young and aged oocytes. Several endo-siRNAs that were upregulated in aged oocytes selectively targeted Kifc1 and Kifc5b; members of the kinesin protein family that were confirmed as being reciprocally reduced in the aged oocytes. The implications of reduced Kifc1 and Kifc5b expression were explored using complementary siRNA-mediated knockdown and pharmacological inhibition strategies, both of which led to increased rates of aneuploidy in otherwise healthy young oocytes. Collectively, our data raise the prospect that dysregulation of sncRNA expression, particularly endo-siRNA, may contribute to the age-dependent deterioration of oocyte quality.
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.
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:Reproductive aging is a major cause of fertility decline, attributed to decreased oocyte quantity and competence. Follicular somatic cells play crucial roles in the growth and development of the oocyte by providing nutrients and regulatory factors. Here we investigated how oocyte quality is affected by its somatic cell environment by creating chimeric follicles, whereby an oocyte from one follicle was transplanted into and cultured within another follicle whose native oocyte was removed. Somatic cells within the chimeric follicle re-establish connections with the oocyte and support oocyte growth and maturation in a three-dimensional (3D) culture system. We show that young oocytes transplanted into aged follicles exhibited reduced meiotic maturation and developmental potential, whereas the young follicular environment significantly improved the rates of maturation, blastocyst formation and live birth of aged oocytes. Aged oocytes cultured within young follicles exhibited enhanced interaction with somatic cells, more youth-like transcriptome, remodelled metabolome, improved mitochondrial function, and enhanced fidelity of meiotic chromosome segregation. These findings provide the basis for a future follicular somatic cell-based therapy to treat age-associated female infertility.
Project description:The decline in oocyte quality is a limiting factor of female fertility; however, strategies to maintain the oocyte quality of aged women are not available. In this study, we showed that growth hormone (GH) supplementation in vivo not only alleviated the decline in oocyte number caused by aging, but also improved the quality and developmental potential of aged oocytes. Strikingly, GH supplementation reduced aneuploidy in aged oocytes. Proteomic analysis indicated that the ERK1/2 pathway was involved in the reduction in aneuploidy rate of aged oocytes, as confirmed both in vivo and in vitro. In addition, JAK2 might be involved in the regulation of ERK1/2 by GH in aged oocytes. Collectively, our findings revealed that GH supplementation protects oocytes from aging-related aneuploidy and enhances the quality of aged oocytes, and could be used to improve the outcome of assisted reproduction in aged women.
Project description:This study compares miRNA expression profiles in mouse oocytes as young oocytes vs aged oocytes, and growing oocytes vs small oocytes from primordial follicles. Oocytes were derived from the ovary of young (6-8 week-old) C57BL/6 mice and aged (41-43 week-old) mice and pooled according to whether they were 20 to 50 um or 60 to 80 um in diameter. Of oocytes with the diameter of more than 60um, oocyte from young mice are called ‘young oocytes’ and those from aged mice near the end of their reproductive life span are called ‘aged oocytes’ to analyze the miRNA profiling associated with aging. They were also each called ‘small oocytes’ or ‘large oocytes’ from the size of 60um so as to investigate miRNA profiling associated with growing. Total RNA from oocytes was isolated using mirVana miRNA Isolation Kit (Applied Biosystems). MiRNA expression was profiled using Agilent's Mouse miRNA Microarray Kit (G4472A) annotated against the Sanger miRBASE 10.1 database of miRNAs. This miRNA microarray was provided by Agilent Technologies (Santa Clara, CA). Each sample was run in duplicate.
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:Decreased oocyte quality is a major determinant of age-associated fertility decline which lacks an effective treatment strategy. The secretome of mesenchymal stem cells (MSC-sec) contains various bioactive factors and has the potential to improve oocyte quality. In this study, MSC-sec treatment significantly increased first polar body emission, improved spindle assembly, reduced aneuploidy rate, and promoted maternal mRNA degradation in aged mouse oocytes, whereas the addition of BDNF antibody blocked the effects of MSC-sec. Furthermore, BDNF treatment alone also improved the oocyte quality from aged mice. Mechanistically, both MSC-sec and BDNF activated the ERK1/2 signaling pathway to increase the expression of DAZL and BTG4 in aged oocytes. Furthermore, injection of MSC-sec or BDNF into aged mouse ovaries significantly improved oocyte quality and early embryonic development. Finally, we demonstrated that BDNF treatment increased both the fertilization rate and blastocyst formation of aged human oocytes. Our study identified BDNF as the functional component of MSC-sec to improve the quality and development potential of aged oocytes by activating the ERK1/2 signaling pathway, suggesting that BDNF has the potential to mitigate age-related decline in oocyte quality.