Abstract:
Simulated Physiological Oocyte Maturation (SPOM) mimics in vitro the physiological events of oocyte maturation. The system uses cAMP modulators in two steps (pre IVM and IVM) and has presented promising results that are arousing the curiosity of IVF programs in different animal species, generating several papers, adaptations, and controversies worldwide. This study systematically analyses the data in the literature on the use of SPOM and compares the outcomes to the original paper (Albuz et al. Hum. Rep., 25: 2999-3011 2010), classifying them into success or failure. The PubMed, Scopus, and Google Scholar databases were searched and 22 studies were included, from which data on 26 experiments were extracted and evaluated via descriptive statistical analysis. Only experiments that assessed the blastocyst rate (BR) were considered for the success parameter, i.e. success (increase in BR) or failure (either no difference or a reduction in BR). The experiments applied the SPOM system in the following species: cattle, sheep, goats, mice, mares and cats. Three experiments (3/26) could not be evaluated for success or failure, and of the remaining, 34.7% (8/23) succeeded in improving blastocyst production. More than two-thirds (69.2%, 18/26) of experiments were conducted in cattle; of those, 86.8% (13/15) used TCM-199 as the IVM media, and 22.2% did not use forskolin or IBMX modulators as indicated in the original study. Also, 27.7% (5/18) of the experiments in cattle used the same type and dose of FSH, and 22% (4/18) used the same protein source and concentration as indicated in the original study. All experiments conducted in mice (3) kept the parameters of the original study in terms of forskolin and IBMX doses and BSA and FSH concentrations, however, they removed cilostamide from IVM. Cilostamide was used during IVM in more than half (53.8%) of all experiments, but only in cattle and sheep. Considering oocyte and embryo assessments, six experiments assessed cAMP levels and most (5/6) of these observed an increase: in cattle (2), sheep (2), and mice (1). Ten experiments evaluated the effect of SPOM on nuclear maturation, and in 90% (9/10), the SPOM system was able to arrest meiosis (cattle, sheep and mice). Thirteen experiments evaluated the total cell number (cattle, mice and sheep), and six (6/13) showed an increase. Our findings clearly indicate difficulties in reproducing the SPOM system worldwide, demonstrating that the meiosis arrest is not sufficient to ensure successful SPOM application. They also suggest that the different supplements used in the IVM medium and/or their interaction with modulators for different durations may produce a significant bias that affects experimental success.
摘要:
模拟生理卵母细胞成熟(SPOM)在体外模拟卵母细胞成熟的生理事件。该系统在两个步骤(IVM前和IVM)中使用cAMP调制器,并取得了有希望的结果,这些结果引起了不同动物物种对IVF计划的好奇心,生成几篇论文,适应,和全世界的争议。本研究系统分析了文献中有关SPOM使用的数据,并将结果与原始论文进行了比较(Albz等人。哼。Rep.,25:2999-30112010),将它们分为成功或失败。PubMed,Scopus,搜索了谷歌学者数据库,纳入了22项研究,从其中提取26个实验的数据,并通过描述性统计分析进行评估。只有评估囊胚率(BR)的实验被认为是成功参数,即成功(BR增加)或失败(无差异或BR减少)。实验在以下物种中应用了SPOM系统:牛,绵羊,山羊,老鼠,母马和猫。三个实验(3/26)无法评估成功或失败,剩下的,34.7%(8/23)成功地改善了胚泡的产生。超过三分之二(69.2%,18/26)的实验是在牛身上进行的;其中,86.8%(13/15)使用TCM-199作为IVM培养基,22.2%未使用毛喉素或IBMX调节剂,如原始研究所示。此外,27.7%(5/18)的实验在牛中使用相同类型和剂量的FSH,22%(4/18)使用与原始研究中所示相同的蛋白质来源和浓度。在小鼠中进行的所有实验(3)都保持了原始研究的参数,包括毛喉素和IBMX剂量以及BSA和FSH浓度,然而,他们从IVM中去除西洛他胺.在所有实验的一半以上(53.8%)的IVM期间使用西洛他胺,但只有牛和羊。考虑到卵母细胞和胚胎评估,六个实验评估了cAMP水平,其中大多数(5/6)观察到增加:在牛(2)中,绵羊(2)和小鼠(1)。十个实验评估了SPOM对核成熟的影响,在90%(9/10)中,SPOM系统能够阻止减数分裂(牛,绵羊和老鼠)。13个实验评估了总细胞数(牛,小鼠和绵羊),和六个(6/13)显示增加。我们的发现清楚地表明,在全球范围内复制SPOM系统很困难,证明减数分裂的停止不足以确保SPOM的成功应用。他们还表明,在IVM培养基中使用的不同补充剂和/或它们与不同持续时间的调节剂的相互作用可能会产生影响实验成功的显著偏差。