Increased expression of BubR1 protects against aneuploidy in aging oocytes and extends reproductive lifespan
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ABSTRACT: Chromosome aneuploidy increases in oocytes with maternal age, and is considered the leading cause for the increased incidence of infertility, miscarriage, and birth defects. Using mRNA-Sequencing of oocytes from 12 month old mouse versus 3 month young mouse, we identified a spindle assembly checkpoint gene, BubR1, whose expression was significantly decreased. We employed a mRNA microinjection based approach to increase BubR1 expression in aging oocytes. We find that increased expression of BubR1 protects against aneuploidy and chromosome misalignment in aging oocytes. After in vitro fertilization, the embryos derived from BubR1 increased expression aging oocytes exhibited chromosome stability as robust as those of the young ones. Furthermore, following embryo transfer, these embryos showed greatly improved developmental competency, with comparable levels of full-term development to those of the young ones. These results indicate that the decline in oocyte quality may be reversible and could lead to treatments that prolong female fertility. Examination of the effect of maternal aging on the mRNA expression in the mature oocytes of the female mice. Naturally ovulated mature oocytes (MII stage) were collected from 6 young (3 month) and 6 aging (12 month) female mice (3 oocytes per mice, 18 oocytes for each group).
Project description:Slimming is globally prevalent especially in young women, and it may contribute to the metabolic health of their offspring. Whereas some Lamarckian ideas about environmental inheritance have been dismissed, increasing evidence suggest that certain acquired traits can be transmitted to the next generation. It is therefore of great interest to determine how and to what extent a maternal lifestyle change contributes to their offspring. Here we show that enriched environment (EE) induced maternal slimming improves general health and reprograms metabolic gene expression in mice offspring. EE in mothers induced decreased body weight, adiposity, and improved glucose tolerance and insulin sensitivity. Relative to controls, their offspring exhibited improved general health such as reduced fat accumulation, enhanced metabolic parameters as well as glucose tolerance and insulin sensitivity. Maternal slimming altered the expression of 1,732 genes in the liver of offspring, with coherent downregulation of genes involved in lipid and cholesterol biosynthesis. Epigenomic profiling in offspring revealed numerous changes in cytosine methylation depending on maternal slimming, including hypermethylation of several genes involved in lipid biosynthesis, correlated with the downregulation of these genes. Maternal slimming also altered overall transcriptome patterns in mature oocytes, which contributes largely to the metabolic health and gene expression patterns in offspring. Overall, our studies suggest that maternal slimming have a beneficial role in regulating metabolic profiles in offspring, implying that it might be considered as a potential strategy to reverse the global prevalence of obesity and related metabolic syndromes. Examination of the effect of 2 different maternal lifestyles, control and slimming, on the mRNA expression in the mature oocytes of the female mice. Naturally ovulated mature oocytes (MII stage) were collected from 3 control and 3 slimming female F0 founders (3 oocytes per mouse, 9 oocytes for each group).
Project description:Chromosome aneuploidy increases in oocytes with maternal age, and is considered the leading cause for the increased incidence of infertility, miscarriage, and birth defects. Using mRNA-Sequencing of oocytes from 12 month old mouse versus 3 month young mouse, we identified a spindle assembly checkpoint gene, BubR1, whose expression was significantly decreased. We employed a mRNA microinjection based approach to increase BubR1 expression in aging oocytes. We find that increased expression of BubR1 protects against aneuploidy and chromosome misalignment in aging oocytes. After in vitro fertilization, the embryos derived from BubR1 increased expression aging oocytes exhibited chromosome stability as robust as those of the young ones. Furthermore, following embryo transfer, these embryos showed greatly improved developmental competency, with comparable levels of full-term development to those of the young ones. These results indicate that the decline in oocyte quality may be reversible and could lead to treatments that prolong female fertility.
Project description:Interleukin-15 (IL-15) and IL-2 possess distinct immunological functions despite both signaling through IL-2Rβ and the common cytokine receptor γ-chain, γc, We find that in the IL-15/IL-15Rα/IL-2Rβ/γc quaternary complex structure, IL-15 heterodimerizes IL-2Rβ and γc identically to the IL-2/IL-2Rα/IL-2Rβ/γc complex, despite differing receptor-binding chemistries. IL-15Rα dramatically increases the affinity of IL-15 for IL-2Rβ, and this allostery is required for IL-15 trans-signaling versus IL-2 cis-signaling. Consistent with the identical IL-2Rβ/γc dimer geometry, IL-2 and IL-15 exhibited similar signaling properties in lymphocytes, with any differences resulting from disparate receptor affinities. Thus, IL-15 and IL-2 induce similar signals, and the cytokine-specificity of IL-2Rα versus IL-15Rα determines cellular responsiveness. These results provide important new insights for specific development of IL-15- versus IL-2-based immunotherapeutics. RNA-Seq is conducted in mouse CD8+ T cells, not treated or treated with IL2 or IL15 for indicated concentrations (1nM or 500nM) and times (4hr or 24hr).
Project description:We performed an RNA Sequencing experiment on dorsal hippocampal tissue from six groups of animals: Aging (18-20-month-old) HDAC3flox/flox homecage (H3F-HC); Aging (18-20-month-old) HDAC3flox/flox 60min post training (H3F-BV); Aging (18-20-month-old) wildtype homecage (OWT-HC); Aging (18-20-month-old) wildtype 60min post training (OWT-BV); Young (2-4-month-old) wildtype homecage (YWT-HC); Young (2-4-month-old) wildtype 60min post training (YWT-BV). Homecage animals were sacrificed directly from the animal's cage. Behavior animals were sacrificed sixty minutes following a 10min Object Location Memory training session.
Project description:We report genome-wide characterization of GATA3 binding sites in eleven well-defined developmental and effector cell types of the T lymphocyte lineage. By utilizing a conditional allele of GATA3, we investigated the impact of GATA3 expression on the mRNA expression patterns in several of these cell types. Correlation of GATA3 binding with gene expression changes indicates that GATA3 regulates a large number of stage- and cell-specific genes involved in multiple signaling and transcriptional pathways critical for T cell differentiation and immune responses. 1) RNA-Seq: Examination of RNA transcript levels in 6 cell types in wild-type and Gata3-knockout cells. 2) ChIP-Seq: Examination of GATA3 binding sites in 11 cell types. 3) Methyl-Seq: Examination of histone modification levels in DP cells from wild-type and Gata3-knockout mice.
Project description:In mammalian females, quiescent primordial follicles serve as the ovarian reserve and sustain normal ovarian function and egg production via folliculogenesis. The loss of primordial follicles causes ovarian aging. Cellular senescence, characterized by cell cycle arrest and production of the senescence-associated secretory phenotype (SASP), is associated with tissue aging. In the present study, we report that some quiescent primary oocytes in primordial follicles become senescent in adult mouse ovaries. The senescent primary oocytes share senescence markers characterized in senescent somatic cells. The senescent primary oocytes were observed in young adult mouse ovaries, remained at approximately 15% of the total primary oocytes during ovarian aging from 6 months to 12 months, and accumulated in aged ovaries. Administration of a senolytic drug ABT263 to 3-month-old mice reduced the percentage of senescent primary oocytes and the transcription of the SASP cytokines in the ovary. In addition, led to increased numbers of primordial and total follicles and a higher rate of oocyte maturation and female fertility. Our study provides experimental evidence that primary oocytes, a germline cell type that is arrested in meiosis, become senescent in adult mouse ovaries and that senescent cell clearance reduced primordial follicle loss and mitigated ovarian aging phenotypes.
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.