A novel system used by pre-implantation mammalian embryos to amplify environmentally-induced changes in sperm miRNA content after fertilization.

植入前哺乳动物胚胎使用的一种新系统，可放大受精后环境引起的精子 miRNA 含量变化。

• 批准号: 10510748
• 负责人: LARRY FEIG
• 金额: $ 24.75万
• 依托单位: TUFTS UNIVERSITY BOSTON
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-10 至 2024-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10510748
• 关键词: Adult; Affect; Animal Model; Anxiety; Caenorhabditis elegans; Cells; Chronic; Embryo; Embryonic Development; Environment; Enzymes; Epididymis; Epigenetic Process; Epithelial Cells; Exposure to; Family; Family member; Female; Fertilization; Funding; Gene Expression; Generations; Genes; Genetic Transcription; Germ Cells; Goals; Grant; Human; Life; Lower Organism; Mammals; Measures; Mediating; Messenger RNA; MicroRNAs; Mus; Nucleotides; Oocytes; Phenotype; Physiologic pulse; Plants; Procedures; Process; Psychological Stress; RNA; RNA-Directed RNA Polymerase; Reporting; Resolution; Rodent; Stimulus; Stress; System; Tail; Testing; Transcript; base; blastocyst; design; embryo cell; environmental change; exosome; experience; experimental study; human embryonic stem cell; interest; male; member; men; next generation; novel; offspring; pre-miRNA; preimplantation; pri-miRNA; social; sperm cell; trait; transgenerational epigenetic inheritance; transmission process; zygote

Summary Transgenerational epigenetic inheritance involves transmission of the effects of experiences to offspring across generations via epigenetic changes in germ cells. It is well established in lower organisms like C. elegans and plants, and growing evidence implies a similar phenomenon occurs in mammals including humans. Much support for this process in rodents derives from experiments on male mice exposed to chronic psychological stress, where stress-type specific changes in the levels of specific sperm miRNAs have been implicated in transmitting stress-associated traits across generations. However, sperm contain much lower levels of miRNAs than those of most cells, including those in early embryos. This fact implies a system must exist in embryos to magnify and extend environmental changes in their sperm content after fertilization. In fact, an auto-amplification systems exists and is necessary for transgenerational epigenetic inheritance in lower organisms. However, an analogous system has not been reported in mammals. This grant is driven by our recent discovery of what appears to be a novel amplification system for the sperm miR-34/449 family. These mRNAs are of particular interest in this context because we implicated them in the paternal transmission of enhanced anxiety and defective sociability displayed specifically to female offspring of male mice exposed to Chronic Social Instability (CSI) stress. We found that CSI stress reduces levels of miR-34b/c and miR-449a/b not only in sperm of male mice exposed to CSI stress but also in early embryos derived from them through at least the blastocyst stage of early embryogenesis, even though the levels of these miRNAs in sperm are much lower than that normally present in preimplantation embryos. The amplification system we uncovered is based on our findings that miR- 34c normally positively regulates the expression of its own gene and that for miR-449 in preimplantation mouse embryos, and that this system appears to be suppressed in embryos from CSI stressed males. Surprisingly, we do not detect changes in the primary transcripts or partially processed forms of miR-34c in these embryos, suggesting sperm miR-34, and possibly miR-449, regulates the stability of embryo produced members of this miRNA family. The potential relevance of this system to humans is supported by our findings that; a) both miR- 34 and miR-449 levels are also reduced in sperm of men who experienced severe abusive and/or dysfunctional family life when young; and b) a similar amplification system appears to exist in human embryonic stem cells. The goal of this proposal is to test this hypothesis by measuring the half-lives of miR-34 and miR-449 and their extent of their “tailing” and “trimming”, which are part of the degradation process. We anticipate that these findings will justify more long-term funding for experiments that reveal the how these miRNAs control their own degradation, since this process may necessary for specific forms of transgenerational epigenetic inheritance in both mice and men.

概括 跨代表观遗传遗传涉及将经验的影响传播给后代 通过生殖细胞的表观遗传变化，几代人。它在诸如秀丽隐杆线虫等较低的生物中已建立 植物和越来越多的证据意味着在包括人类在内的哺乳动物中也发生了类似的现象。很多 啮齿动物中对此过程的支持来自于暴露于慢性心理的雄性小鼠的实验 压力，在应力类型的特定精子miRNA水平的特异性变化已与 传播与世代相传的应激相关性状。但是，包含较低水平的miRNA的精子 比大多数细胞，包括早期胚胎的细胞。这个事实意味着系统必须存在于胚胎中 受精后放大并扩展其精子含量的环境变化。实际上，自动放大 系统存在，对于低生物体中的转化表观遗传遗传是必不可少的。但是，一个 在哺乳动物中尚未报告类似系统。这笔赠款是由我们最近发现的 对于精子miR-34/449家族的新型扩增系统似乎是一种新颖的扩增系统。这些mRNA特别 在这种情况下的兴趣，因为我们在增强动画的父亲传播中实施了它们 专门针对暴露于慢性社会不稳定的雄性小鼠的女性后代的社交性有缺陷 （CSI）压力。我们发现CSI应力降低了miR-34b/c和miR-449a/b的水平，不仅在男性的精子中 暴露于CSI胁迫的小鼠，但在早期的胚胎中也至少通过它们的胚泡阶段 早期的胚胎发生，即使精子中这些miRNA的水平远低于通常 存在于植入前胚胎中。我们发现的放大系统是基于我们的发现，即 34C通常对其自身基因的表达进行积极调节，而对于植入前小鼠中的miR-449 胚胎，该系统似乎在CSI压力男性的胚胎中被抑制。令人惊讶的是，我们 请勿检测到这些胚胎中主要转录本或部分处理的miR-34c的变化， 建议精子miR-34和可能的miR-449调节胚胎的稳定性产生的成员 mirna家族。我们的发现支持该系统与人类的潜在相关性： a）两个mir- 34和miR-449水平也降低了严重虐待和/或功能失调的男性的精子 年轻时的家庭生活； b）在人类胚胎干细胞中似乎存在类似的扩增系统。 该提案的目的是通过测量miR-34和miR-449及其的半衰期来检验这一假设 它们的“尾巴”和“修剪”的程度，这是退化过程的一部分。我们预计这些 调查结果将为实验提供更多的长期资金，以揭示这些miRNA如何控制自己的 降解，因为此过程可能需要特定形式的转化表观遗传遗传 老鼠和男人。