Melamine negatively affects oocyte architecture, oocyte development and fertility in mice
Melamine negatively affects oocyte architecture, oocyte development and fertility in mice
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DOI：
10.1093/humrep/dev091
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发表时间：
2015-07-01
影响因子：
6.1
通讯作者：
Sun, Shao-Chen
中科院分区：
文献类型：
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作者：
Duan, Xing;Dai, Xiao-Xin;Sun, Shao-Chen
研究问题：三聚氰胺对体内卵母细胞发育和生育有毒性影响吗？摘要回答：三聚氰胺对卵母细胞的质量和生育力有毒性影响，因为它影响卵母细胞的细胞骨架，诱导细胞凋亡和自噬，以及体内小鼠模型的表观遗传修饰。已知：三聚氰胺是一种化学化合物，广泛用于氨基树脂和塑料的制造。2008年，据报道，中国的奶粉和婴儿配方奶粉中掺入了三聚氰胺，这引发了全球对食品安全的担忧。摄入三聚氰胺可能会导致生殖损害，并可能导致膀胱癌或肾结石。研究设计、大小、持续时间：将小鼠随机分为三组，分别喂食含三聚氰胺(0、10和50 mg/kg/天)的饲料8周。研究了三聚氰胺对雌性动物体内生殖的影响。实验材料、环境、方法：我们用免疫荧光染色、免疫印迹和qRT-PCR检测了三聚氰胺对卵母细胞质量的影响。(1)喂饲三聚氰胺的小鼠卵巢重量减轻。卵母细胞的发育能力也降低，表现为极体排出率降低。(Ii)三聚氰胺喂养导致卵母细胞细胞骨架异常，表现为纺锤体畸变率增加和肌动蛋白微丝表达减少。(Iii)暴露于三聚氰胺的卵母细胞线粒体分布异常和早期凋亡/自噬的发生率较高，表现为微管相关蛋白1轻链3(Lc3)蛋白表达水平和caspase9、自噬相关蛋白14(Atg14)和lc3mRNA水平的增加。(4)荧光强度分析显示，喂饲三聚氰胺的小鼠卵母细胞DNA甲基化水平降低。组蛋白甲基化水平也发生改变，三甲基组蛋白H3(Lys4)(H3K4me2)水平升高，三甲基组蛋白H3(Lys9)(H3K9me3)、二甲基-组蛋白H3(Lys9)(H3K9me2)和三甲基组蛋白H3(Lys27)(H3K27me3)水平降低。(V)与对照组相比，喂食三聚氰胺的小鼠的产仔数显著减少。限制，谨慎的理由：尽管我们研究了三聚氰胺对卵母细胞质量和生育能力的可能影响，但我们没有确定三聚氰胺对后代发育的影响。研究结果的广泛意义：我们的发现表明三聚氰胺在卵母细胞质量和生育能力方面发挥着重要作用。这些信息有助于更好地了解三聚氰胺对女性生殖系统的毒性。研究资金/利益竞争：本研究得到了中国国家基础研究计划(2014CB138503)和江苏省自然科学基金(BK20140030)的资助。两位作者没有利益冲突要披露。
STUDY QUESTION: Does melamine have a toxic effect on oocyte development and fertility in vivo?SUMMARY ANSWER: Melamine had toxic effects on oocyte quality and fertility due to its effects on the oocyte cytoskeleton, apoptosis and autophagy induction, and epigenetic modifications in an in vivo mouse model.WHAT IS KNOWN ALREADY: Melamine is a chemical compound that is widely used during the manufacture of amino resins and plastics. In 2008, melamine was reported to adulterate milk and infant formulas in China, which sparked food safety concerns worldwide. Ingesting melamine may result in reproductive damage, and bladder or kidney stones, which can lead to bladder cancer.STUDY DESIGN, SIZE, DURATION: Mice were randomly assigned to three groups and fed a diet that included melamine (0, 10 and 50 mg/kg/day) for 8 weeks. The in vivo effect of melamine on female reproduction was examined.PARTICIPANTS/MATERIALS, SETTING, METHODS: We used immunofluorescent staining, western blotting and qRT-PCR to examine the effect of melamine on oocyte quality.MAIN RESULTS AND THE ROLE OF CHANCE: Our results showed the following effects of this melamine-containing diet. (i) Ovary weights were reduced in melamine fed mice. Oocyte developmental competence was also reduced, as shown by reduced polar body extrusion rates. (ii) Melamine feeding resulted in abnormal oocyte cytoskeletons, as shown by increased rates of aberrant spindles and reduced actin microfilament expression. (iii) Melamine exposed oocytes had higher rates of abnormal mitochondrial distributions and early stage apoptosis/autophagy, which were shown by increased microtubule-associated protein 1 light chain 3 (LC3) protein expression level and caspase 9, autophagy-related protein 14 (atg14), and lc3 mRNA levels. (iv) Fluorescence intensity analysis showed that DNA methylation levels were reduced in the oocytes of melamine fed mice. Histone methylation levels were also altered, as Di-methyl-Histone H3 (Lys4) (H3K4me2) level was increased and Tri-methyl-Histone H3 (Lys9) (H3K9me3), Di-methyl-Histone H3 (Lys9) (H3K9me2), and Tri-methyl-Histone H3 (Lys27) (H3K27me3) levels were reduced in oocytes from melamine fed mice. (v) The litter sizes of melamine fed mice were significantly reduced when compared with those of controls.LIMITATIONS, REASONS FOR CAUTION: Although we examined the possible effects of melamine on oocyte quality and fertility, we did not determine the effect of melamine on offspring development.WIDER IMPLICATIONS OF THE FINDINGS: Our findings indicate that melamine plays a major role in oocyte quality and fertility. This information could contribute to a better understanding of melamine toxicity in female reproduction.STUDY FUNDING/COMPETING INTERESTS: This study was supported by the National Basic Research Program of China (2014CB138503) and the Natural Science Foundation of Jiangsu Province (BK20140030). The authors have no conflict of interest to disclose.