The effects of cycloastragenol on bovine embryo development, implantation potential and telomerase activity
Abdul Majid Khan
A , Muhammad Idrees A B , Chalani Dilshani Perera C , Zaheer Haider A , Myeong-Don Joo A , Ji-Su Kang A , Seo-Hyeon Lee A and Il-Keun Kong A B D *
+ Author Affiliations
- Author Affiliations
A Division of Applied Life Science (BK21 Four), Gyeongsang National University, Jinju, Gyeongnam Province 52828, Republic of Korea.
B Institute of Agriculture and Life Science, Gyeongsang National University, Jinju, Gyeongnam Province, Republic of Korea.
C Department of Animal Science, Gyeongsang National University, Jinju, Republic of Korea.
D The King Kong Corp. Ltd., Gyeongsang National University, Jinju, Gyeongnam Province 52828, Republic of Korea.
Reproduction, Fertility and Development 35(10) 527-538 https://doi.org/10.1071/RD22280
Published online: 2 June 2023
© 2023 The Author(s) (or their employer(s)). Published by CSIRO Publishing
Abstract
Context: Telomerase reverse transcriptase is a key factor responsible for structural and cellular alterations in aged oocytes and changes in the structure of the zona pellucida and mitochondria. Telomerase expression is reduced in aged cumulus oocyte complexes, and its activation or enhanced expression would be beneficial for in vitro oocyte maturation and in vitro embryo development.
Aims: This study aimed to investigate telomerase activation by cycloastragenol and its effect on bovine oocyte in vitro maturation, fertilisation, and early embryo development.
Methods: We used qPCR, Western blot, immunofluorescence, reactive oxygen species (ROS) assay,TUNEL assay, JC-1 assay, and invasion assay to analyse the affect of cycloastragenol (CAG) on bovine oocyte maturation, embryo development, embryo quality and implantation potential.
Key results: Cycloastragenol treatment of oocytes in in vitro maturation (IVM) media significantly (P < 0.05) improved oocyte IVM (90.87%), embryo cleavage (90.78%), blastocyst hatching (27.04%), and embryo implantation potential. Telomerase also interacts with mitochondria, and JC-1 staining results showed significantly (P < 0.05) higher mitochondrial membrane potential (ΔΨm) in the CAG-treated group. Furthermore, the inner cell mass (OCT4 and SOX2) and trophoblasts (CDX2) of the control and CAG groups were examined. Moreover, CAG treatment to primary cultured bovine cumulus cells substantially enhanced telomerase activity.
Conclusions: Telomerase activation via cycloastragenol is beneficial for bovine oocyte IVM and for the production of high-quality bovine embryos.
Implications: Cycloastragenol is a natural telomerase activator, and could be useful as a permanent component of oocyte maturation media.
Keywords: bovine oocyte, cycloastragenol, embryo development, embryo implantation, in vitro oocyte maturation, inner cell mass, telomerase reverse transcriptase, trophoblast.
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