Project description:Specialized surveillance mechanisms are essential to maintain the genetic integrity of germ cells, which are not only the source of all somatic cells but also of the germ cells of the next generation. DNA damage and chromosomal aberrations are, therefore,
Project description:Advanced maternal age, defined as 35 years or older, is associated with a decline in both ovarian reserve and oocyte quality, which leads to the female infertility, pregnancy loss, fetal anomalies, stillbirth, and obstetric complications. At present, the effective approaches to counteract the maternal age-related decay of oocyte quality are still not fully determined. Here, we report that in vivo supplementation of nicotinamide mononucleotide (NMN) efficaciously ameliorates the quality of oocytes from naturally aged mice by recovering nicotinamide adenine dinucleotide (NAD + ) levels in oocytes. NMN supplementation increases the number of antral follicles, ovulated oocytes and matured oocytes from aged mice. Specifically, NMN supplementation maintains the normal spindle/chromosome structure and dynamics of cortical granule component ovastacin to ensure the meiotic competency and fertilization ability of aged oocytes. Moreover, single cell transcriptome analysis shows that the beneficial effect of NMN on the aged oocytes is mediated by the restoration of the mitochondrial function, thereby reducing the accumulated ROS to suppress the occurrence of apoptosis. To sum up, our data reveal that supplementation of NMN is a feasible approach to prevent oocyte quality from advanced maternal age-related deterioration, contributing to improve the reproductive outcome of aged women and the assisted reproductive technology.
Project description:STUDY QUESTION: Does maternal age affect the maturated oocyte quality and the fol-lowing development after fertilization in human? SUMMARY ANSWER: Maternal age affects the quality of maturated oocytes by altering the stored mRNA levels in human, such as TOP2B. WHAT IS KNOWN ALREADY: Intracellular mRNAs in maturated oocytes are tran-scripted from the maternal genome during oogenesis and important for the zygotic genome activation (ZGA) after fertilization. Microarray data showed that maternal age affected polyadenylated transcript abundance in human oocytes. These genes are involved in in signaling pathway related to cell cycle regulation, chromosome alignment. However, which genes are the key genes affected by maternal age and important for the development after fertilization had not been reported. Therefore, single-cell RNA sequencing (scRNA-Seq) technology is employed in this study to screen the key genes affected by maternal age in human maturated oocytes. STUDY DESIGN, SIZE, DURATION: We isolated mRNA from maturated (MII) oo-cytes donated by IVF or ICSI patients (three oocytes from young (≤ 30 years) and three oocytes from advanced maternal age (≥ 40 years) patients) undergoing controlled ovarian stimulation. Thus, a total of six maturated oocytes were individually processed for scRNA-seq analysis. The key genes screened from scRNA-seq analysis are confirmed using mouse model. PARTICIPANTS/MATERIALS, SETTING, METHODS: Patients undergoing infertility treatment at the Yuhuangding Hospital of Yantai underwent ovarian stimulation with FSH and received hCG for final follicular maturation prior to ul-trasound guided oocyte retrieval. We isolated RNA, generated single cell RNA-seq librar-ies (Smart-Seq2) and sequenced by Illumina Hiseq X-ten platform with 150 bp paired-end. Bioinformatics analysis of the sequencing data was done to find the biological processes and key genes that led to the decline in the quality of oocytes with advanced maternal age. To validate the findings, we used mouse model and validated candidate genes by RT-PCR and knockdown experiments. MAIN RESULTS AND THE ROLE OF CHANCE: We identified 1439 genes differentially expressed between older and younger women's maturated oocytes (|foldchange|>2, P < 0.05). These genes are significantly enriched with annotations related to transporter activity, cytoskeleton, oxidative stress, catalytic activity, immune function, cellular senescence and biosynthesis. The key candidate gene TOP2B was found by protein interaction network analysis, and knockdown verification on young mouse maturated oocytes showed that TOP2B was a key gene affecting the oocyte quality and disturbing early embryo development. LARGE SCALE DATA Raw data from this study can be accessed through GSE. LIMITATIONS, REASONS FOR CAUTION: The human maturated oocytes used in this study were from patients with different causes of infertility and may affect oocyte gene expression. In addition, the study was based on a lim-ited number of patients, and there are possible natural biological variance existed in human samples. WIDER IMPLICATIONS OF THE FINDINGS: For the first time, we used scRNA-seq to detect global gene transcriptome of maturated oocytes in young and older women. These results are useful to indicate the molecular mechanisms of female ovary aging and establishing a criterion to evaluate the quality of oocytes in women with advanced maternal age. STUDY FUNDING/COMPETING INTERESTS: This research was supported by the National Key Research and Development Program of China (2018YFC1004304, 2016YFA0100203), Medical and Health Science Technology Development Plan Project of Shandong Province (Grant#. 2017WS566). There are no competing interests.
Project description:Elevated ambient temperature results in heat stress which is a major concern for productivity and product quality due to its negative impact on animal health, productivity and product quality. As global warming becomes more and more serious, the impact of heat stress (HS) on animal husbandry cannot be ignored. However, the effect of NMN on the quality of porcine oocytes after heat stress and the prevention strategies are not yet fully understood. Here, we report that nicotinamide mononucleotide (NMN) treatment ameliorates the quality of porcine oocytes exposed to heat stress. Specifically, we found that HS caused oocyte meiosis failure by disrupting the dynamics and arrangement of meiotic organelles, showing obvious damage to cytoskeleton assembly. Furthermore, heat stress can cause damage to oocyte mitochondria, which is an indicator of oocyte cytoplasmic maturation. On the contrary, supplementation of NMN can improve this phenomenon, maintain the normal chromosome/spindle structure, and the dynamics of CGs and its core content ovastacin.
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:The European clam, Ruditapes decussatus (Linnaeus, 1758) is a bivalve mollusc of the family Veneridae native to the European Atlantic and Mediterranean coastal waters. Its production is exclusively based on natural recruitment, which is subject to high annual fluctuations due to adversely affected by pollution and other environmental factors. A microarray-based analysis was performed with the objectives of describe genomic feature of oocytes and identify potential markers of oocyte quality in the economically important European clam, Ruditapes decussatus. The oocytes of a total of 25 females from Ria de Aveiro, Western coast of Portugal, were selected for this study and their quality was estimated by early developmental success until D-larval rate, under controlled conditions.
Project description:p63, a homologue of the tumor suppressor p53, is critical for the development and maintenance of squamous epithelia. p63 is specifically expressed in the basal layers of stratified epithelial tissues, and is considered to be a specific marker for cells of this type. The role of p63 in tumorigenesis remains poorly defined. Numerous studies have highlighted the oncogenic potential of the predominant p63 isoform, ΔNp63α; however, data suggests that other p63 proteins can act as tumor suppressors or alter the metastatic potential of tumors. ΔNp63α can act as a transcriptional repressor, but the link between the transcriptional functions of p63 and its biological role is still unclear. In this study, we used a loss-of-function approach to investigate the transcriptional programs controlled by p63. Keywords: cell line panel
Project description:Here we integrated multi-omics profiles including transcriptomics, DNA accessibility and capture Hi-C data to explore how p63 shapes local chromatin architecture in skin keratinocytes isolated from EEC syndrome patients. Surprisingly, we observed decreased chromatin accessibility in a number of DNA looping nodes which were co-mediated by p63 and CTCF. Our findings not only identified a new aspect of the bookmark function of p63, but also shed light on the disease mechanism underlined p63 dysfunction. Therefore, we propose p63 as a spatial genome organizer by modulating a subset of DNA loops with CTCF and therefore fine-tuning transcription programs required for skin keratinocytes.
Project description:A central challenge in human cancer therapy is the identification of pathways that control tumor cell survival and chemosensitivity in the absence of functional p53. The p53-related transcription factors p63 and p73 exhibit distinct, p53-independent roles in development and cancer: p73 promotes genome stability and mediates chemosensitivity, while p63 largely lacks these p53-like functions and instead promotes proliferation and cell survival. Here, we identify a new and physiologically important mechanism of p63/p73 cross-talk which governs the balance between pro-survival and pro-apoptotic programs in both human and murine squamous cell carcinoma. Through comprehensive profiling of p63-regulated microRNAs (miRs), we identified a subset which target p73 for inhibition, including miR-193a-5p, a direct endogenous transcriptional target repressed by p63 and activated by pro-apoptotic p73 isoforms in both normal cells and tumor cells in vivo. Consequently, chemotherapy treatment causes p63/p73-dependent induction of this miR, thereby limiting chemosensitivity due to miR-mediated feedback control of p73. We demonstrate that interrupting this feedback by inhibiting miR-193a suppresses tumor cell viability and induces dramatic chemosensitivity both in vitro and in vivo. Thus, we have identified a direct, miR-dependent regulatory circuit mediating inducible chemoresistance, whose inhibition provides a new therapeutic opportunity in p53-deficient tumors. Knockdown of endogenous p63 by p63-directed or control lentiviral shRNA in JHU-029 human SCC cells at 48h, in duplicate experiments. Array analysis showing the fold-change and direction of change for all miRs regulated > 1.5-fold in p63-ablated versus control samples