Amyloid-like substance in mice and human oocytes and embryos

• Published in: Journal of assisted reproduction and genetics 2019-09, Vol.36 (9), p.1877-1890
• Main Authors: Pimentel, Ricardo N., Navarro, Paula A., Wang, Fang, Robinson, LeRoy G., Cammer, Michael, Liang, Fengxia, Kramer, Yael, Keefe, David Lawrence
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Amyloid; Amyloid - metabolism; Animals; Blastocyst - metabolism; Body Mass Index; Confocal microscopy; Cytoplasm; Embryogenesis; Female; Fertility; Gamete Biology; Gonadotropins; Gynecology; Human Genetics; Humans; In Vitro Oocyte Maturation Techniques; Maturation; Medicine; Medicine & Public Health; Metaphase; Mice; Microscopy; Microscopy, Fluorescence; Middle Aged; Oocyte Retrieval; Oocytes; Oocytes - metabolism; Ovulation Induction; Parthenogenesis; Pilot Projects; Pituitary (anterior); Prospective Studies; Reproductive Medicine; Transmission electron microscopy; Young Adult; Zona pellucida; Zona Pellucida - metabolism
• ISSN: 1058-0468; 1573-7330
• DOI: 10.1007/s10815-019-01530-w

Purpose To identify and characterize amyloid-like substance (ALS) in human and mouse oocytes and preimplantation embryos. Methods An experimental prospective pilot study. A total of 252 mouse oocytes and preimplantation embryos and 50 immature and in vitro matured human oocytes and parthenogenetic human embryos, from 11 consenting fertility patients, ages 18–45. Fluorescence intensity from immunofluorescent staining and data from confocal microscopy were quantified. Data were compared by one-way analysis of variance, with the least square-MEANS post-test, Pearson correlation coefficients ( r ), and bivariate analyses ( t tests). ALS morphology was verified using transmission electron microscopy. Results Immunostaining for ALS appears throughout the zona pellucida, as well as in the cytoplasm and nucleus of mouse and human oocytes, polar bodies, and parthenogenetic embryos, and mouse preimplantation embryos. In mouse, 2-cell embryos exhibited the highest level of ALS (69000187.4 ± 6733098.07). Electron microscopy confirmed the presence of ALS. In humans, fresh germinal vesicle stage oocytes exhibited the highest level of ALS (4164.74088 ± 1573.46) followed by metaphase I and II stages ( p  = 0.008). There was a significant negative association between levels of ALS and patient body mass index, number of days of ovarian stimulation, dose of gonadotropin used, time between retrieval and fixation, and time after the hCG trigger. Significantly higher levels of ALS were found in patients with AMH between 1 and 3 ng/ml compared to