Effects of exosome-like vesicles on cumulus expansion in pigs in vitro

• Published in: Journal of Reproduction and Development Vol. 63; no. 1; pp. 51 - 58
• Main Authors: MATSUNO, Yuta, ONUMA, Asuka, FUJIOKA, Yoshie A, YASUHARA, Kazuma, FUJII, Wataru, NAITO, Kunihiko, SUGIURA, Koji
• Format: Journal Article
• Language: English
• Published: Japan THE SOCIETY FOR REPRODUCTION AND DEVELOPMENT 2017; Japan Science and Technology Agency; The Society for Reproduction and Development
• Subjects: Animals; Cell interactions; Cells, Cultured; Cumulus Cells - cytology; Exosomes; Exosomes - metabolism; Extracellular vesicles; Female; Follicle Stimulating Hormone - metabolism; Follicle-stimulating hormone; Follicles; Follicular fluid; Follicular Fluid - metabolism; Granulosa cells; Granulosa Cells - metabolism; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Microscopy, Electron, Transmission; Original; Ovarian Follicle - metabolism; Ovarian follicles; Ovary - metabolism; Ovulation; Ovulation - drug effects; Porcine follicular fluid; RNA - metabolism; RNA, Messenger - metabolism; Sus scrofa; Swine; Vesicles
• ISSN: 0916-8818; 1348-4400
• DOI: 10.1262/jrd.2016-124

Cell-secreted vesicles, such as exosomes, have recently been recognized as mediators of cell communication. A recent study in cattle showed the involvement of exosome-like vesicles in the control of cumulus expansion, a prerequisite process for normal ovulation; however, whether this is the case in other mammalian species is not known. Therefore, this study aimed to examine the presence of exosome-like vesicles in ovarian follicles and their effects on cumulus expansion in vitro in pigs. The presence of exosome-like vesicles in porcine follicular fluid (pFF) was confirmed by transmission electron microscopic observation, the detection of marker proteins, and RNA profiles specific to exosomes. Fluorescently labeled exosome-like vesicles isolated from pFF were incorporated into both cumulus and mural granulosa cells in vitro. Exosome-like vesicles were not capable of inducing cumulus expansion to a degree comparable to that induced by follicle-stimulating hormone (FSH). Moreover, exosome-like vesicles had no significant effects on the expression levels of transcripts required for the normal expansion process (HAS2, TNFAIP6, and PTGS2). Interestingly, FSH-induced expression of HAS2 and TNFAIP6 mRNA, but not of PTGS2 mRNA, was significantly increased by the presence of exosome-like vesicles; however, the degree of FSH-induced expansion was not affected. In addition, porcine exosome-like vesicles had no significant effects on the expansion of mouse cumulus-oocyte complexes. Collectively, the present results suggest that exosome-like vesicles are present in pFF, but they are not efficient in inducing cumulus expansion in pigs.