208 Cumulus cells enhance porcine oocyte developmental competence through LH-dependent PI3K-Akt signalling pathway
B. M. Tanga A B , S. Bang A , C. Seo A , S. H. Yun C , H. Lee C , I. S. Mohammed A E , H. S. Park D , S. Lee A , S. I. Kim D and J. Cho AA Chungnam National University, Yuseong-gu, Daejeon, South Korea
B Hawassa University, Hawassa, Ethiopia
C Korea Basic Science Institute, Yuseong-gu, Daejeon, South Korea
D Research Center for Bioconvergence Analysis, Korea Basic Science Research Institute, Yuseong-gu, Daejeon, South Korea
E Zagazig University, Zagazig, Egypt
Reproduction, Fertility and Development 35(2) 233-233 https://doi.org/10.1071/RDv35n2Ab208
Published: 5 December 2022
© 2023 The Author(s) (or their employer(s)). Published by CSIRO Publishing on behalf of the IETS
Cumulus cells (CC) are pivotal in porcine oocyte maturation, but the roles and mechanisms of CC on oocyte maturation are lacking in-depth understanding. We aimed to determine CC-oocyte interaction and possible effects of luteinising hormone (LH) on CC and pathways of the interaction between them. Furthermore, we evaluated exosomes from LH-treated CC on in vitro oocyte maturation, oocyte competence, and subsequent embryo development. We determined that the optimum time for exosome isolation after LH treatment was 24 h (mean particle concentration and average size 3.9 × 106/mL and 133.8 nm, and 3.4 × 106 and 113.6, versus 48 h, respectively) using nanoparticle tracking analysis (NTA). The exosome yield (ultracentrifugation) by CC affected b LH (LH-treated CC yielded a four-fold higher mean concentration than LH-nontreated (4.08 × 108 vs 1.2 × 108 particles/mL). We also confirmed exosomes with transmission electron microscopy (TEM). Proteomics analysis revealed a total of 788 and 686 proteins in Exo-LH+ and Exo-LH−, and 31% and 20.7% proteins were differentially expressed in Exo-LH+ and Exo-LH−, respectively, using DAVID Bioinformatics, NIAID/NIH. Interestingly, functional annotation of differentially expressed proteins revealed 20% and 14% of proteins were related to oocyte development and maturation in Exo-LH+ and Exo-LH−, respectively. The gene ontology and functional annotations (KEGG) of differentially expressed accessions revealed that they were involved in ECM-receptor interaction, tight junction, regulation of actin cytoskeleton, and glycolysis pathways in both Exo-LH+ and Exo-LH−. Whereas proteins that were only expressed in Exo-LH+ have involved PI3K-Akt (phosphatidylinositol 3-kinase) signalling pathway, that is known as a mediator of downstream responses of cell survival, growth, proliferation, cell migration, and angiogenesis; and reported as major pathways in oocyte maturation. We treated denuded oocytes (DO) with exosomes from CC in a serum-free, chemically defined in vitro maturation (IVM) medium as follows: control (DO without Exo), DO treated with Exo from LH treated CC (DO-Exo LH+), DO treated with Exo from LH-nontreated CC (DO-Exo LH−) and COCs, cumulus-enclosed oocyte complexes. The result showed that oocyte maturation was enhanced in DO-Exo LH+ when compared with DO-Exo LH− (72.0% vs 69.0%, respectively; P < 0.05). Furthermore, the blastocyst formation rates were significantly increased in DO-Exo LH+ when compared with DO-Exo LH− (7.6% vs 4.9%, respectively; P < 0.05). The results indicated that CC-derived exosomes can enhance oocyte maturation and blastocyst development rates. LH alters CC-derived exosomes and the PI3K-Akt pathway was differentially expressed in the CC-derived exosomes after LH treatment, which might enhance oocyte maturation. Further investigations are needed to examine the CC-factors and oocyte-factors and the mechanisms and pathways of the interaction between them.
This work was supported by NRF grants # 2021H1D3A2A02040098, 2022R1I1A1A01065412, & 2021R1A2C2009294.
