This study aims to investigate the morphology and distribution of mitochondria, spindles, and chromosomes in oocytes of aged mice and examine the effects of SRT1720 on oocyte maturation. C57BL/6J mice were divided into young (4–8 weeks) and aged groups (48–52 weeks). In vitro maturation media contained (0.05, 0.1, and 1.0 μM) SRT1720 and 0.1-μM dimethyl sulfoxide (DMSO control). The rate of chromosome misalignment and spindle misorientation in oocytes of aged mice were significantly higher than that of young mice (P < 0.01). Fluorescence intensity of mitochondria from oocytes of aged mice was significantly lower than that of young mice (P < 0.01). SRT1720 at 0.1 μM significantly improved oocyte maturation, fertilization, and blastocyst formation in aged mice compared with young mice (P < 0.01). Additionally, immunofluorescence intensity of mitochondria, normal spindle morphology, and chromosome alignment were notably enhanced with SRT1720 when compared with the DSMO control group for metaphase II (MII)-stage oocytes matured in vitro (P < 0.01); 0.1-μM SRT1720 enhanced the expression level of SRIT1 in oocytes from aged mice. In summary, the aged mice oocytes showed increased nuclear and cytoplasmic defects, whereas SRT1720 enhanced oocyte maturation and quality. We concluded that 0.1-μM SRT1720 was an appropriate concentration for in vitro maturation media.

中文翻译：

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SRT1720 提高老年小鼠卵母细胞的成熟度和质量

本研究旨在研究老年小鼠卵母细胞中线粒体、纺锤体和染色体的形态和分布，并研究 SRT1720 对卵母细胞成熟的影响。C57BL/6J 小鼠分为年轻组（4-8 周）和老年组（48-52 周）。体外成熟培养基含有（0.05、0.1 和 1.0 μM）SRT1720 和 0.1-μM 二甲亚砜（DMSO 对照）。老年小鼠卵母细胞染色体错位率和纺锤体错向率均显着高于幼鼠（P  < 0.01）。老年小鼠卵母细胞线粒体荧光强度显着低于幼鼠（P  < 0.01）。与年轻小鼠相比，0.1 μM 的 SRT1720 显着改善了老年小鼠的卵母细胞成熟、受精和囊胚形成（P  < 0.01）。此外，与体外成熟中期 II (MII) 期卵母细胞的 DSMO 对照组相比，SRT1720 的线粒体免疫荧光强度、正常纺锤体形态和染色体排列显着增强（P < 0.01 ）  ；0.1-μM SRT1720 可增强老年小鼠卵母细胞中 SRIT1 的表达水平。总之，老年小鼠卵母细胞显示出更多的细胞核和细胞质缺陷，而 SRT1720 增强了卵母细胞的成熟和质量。我们得出结论，0.1-μM SRT1720 是体外成熟培养基的合适浓度。