Department of Theriogenology and Biotechnology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
Department of Theriogenology and Biotechnology, College of Veterinary Medicine, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
Theriogenology. 2018 Jul 15;115:57-64. doi: 10.1016/j.theriogenology.2017.12.024. Epub 2017 Dec 12.
The paracrine interactions between cumulus-oocyte complexes (COCs) and follicular somatic cells during in vitro maturation (IVM) were investigated. To optimize IVM conditions, many studies have applied exogenous growth factors and cell feeding/co-culture systems using various cell types to replicate the natural follicular microenvironment during IVM. A potential candidate as cell feeders is adipose-derived stem cells (ASCs) which secrete high levels of growth factors that have roles in oocyte maturation. However, the cell donor's age should be considered because biological aging also occurs in stem cells. In the present study, the contributions of ASCs from young and old donors on an IVM co-culture system were analyzed by comparing the oocyte maturation rate, cumulus expansion index, preimplantation development after parthenogenetic activation (PA), and expression of growth factor signaling genes related to oocyte maturation in ASCs, oocytes and cumulus cells under the same culture conditions. Our study demonstrated that the confluence, viability and cell size of ASCs between young and old donors were not significantly different and only the Fibroblast Growth Factor 2 (FGF2) signaling gene showed higher expression in ASCs from young donors. The oocyte maturation rate in the young donor group (87.8 ± 1.2%) was significantly higher than in the old donor (81.1 ± 2.1%) and control (73.8 ± 2.1%) groups. After IVM, most gene expression levels in oocytes and cumulus cells in the co-culture groups were higher than in the control but the apoptotic ratios were reduced. The blastocyst development rates were not different between the young and old donor groups (23.9 ± 1.3% and 20.7 ± 0.8%, respectively) but the percentages were higher in both groups compared to the control group (16.4 ± 1.2%). A similar pattern was also found for blastocyst total cell numbers in that the young donor group (87.5 ± 5.2 cells) was not different than the old donor group (77.5 ± 3.4 cells) but both groups exhibited higher number of cells compared with the control group (57.9 ± 6.0 cells, p < .05). Our study strongly suggested that the co-culture IVM system with ASCs greatly improved the maturation and development rates of porcine oocytes. Moreover, ASCs from young donors more effectively supported porcine oocyte maturation than those from old donors although this difference did not translate into improved developmental competence.
研究了卵丘-卵母细胞复合体（COCs）与卵泡体细胞之间的旁分泌相互作用，在体外成熟（IVM）过程中。为了优化 IVM 条件，许多研究应用外源性生长因子和细胞饲养/共培养系统，使用各种细胞类型来复制 IVM 过程中的天然卵泡微环境。脂肪来源的干细胞（ASCs）作为细胞饲养者是一种潜在的候选者，因为它们分泌高水平的生长因子，在卵母细胞成熟中起作用。然而，应该考虑细胞供体的年龄，因为干细胞也会发生生物衰老。在本研究中，通过比较卵母细胞成熟率、卵丘扩展指数、孤雌激活（PA）后的胚胎前体发育以及在相同培养条件下，来自年轻和老年供体的 ASC 中的生长因子信号基因表达，分析了来自年轻和老年供体的 ASC 对 IVM 共培养系统的贡献。我们的研究表明，年轻和老年供体之间的 ASC 汇合度、活力和细胞大小没有显著差异，只有成纤维细胞生长因子 2（FGF2）信号基因在年轻供体的 ASC 中表达更高。年轻供体组的卵母细胞成熟率（87.8±1.2%）明显高于老年供体组（81.1±2.1%）和对照组（73.8±2.1%）。IVM 后，共培养组中卵母细胞和卵丘细胞的大多数基因表达水平均高于对照组，但凋亡比例降低。年轻和老年供体组之间的囊胚发育率没有差异（分别为 23.9±1.3%和 20.7±0.8%），但与对照组相比，两组的百分比均较高（16.4±1.2%）。囊胚总细胞数也呈现出类似的模式，即年轻供体组（87.5±5.2 个细胞）与老年供体组（77.5±3.4 个细胞）无差异，但两组的细胞数均高于对照组（57.9±6.0 个细胞，p<.05）。我们的研究强烈表明，与 ASC 共培养的 IVM 系统大大提高了猪卵母细胞的成熟和发育率。此外，尽管年轻供体的 ASC 比老年供体的 ASC 更有效地支持猪卵母细胞成熟，但这种差异并没有转化为改善的发育能力。
