Improvement of in vitro-produced bovine embryo treated with coagulansin-A under heat-stressed condition

• Published in: Reproduction (Cambridge, England) Vol. 153; no. 4; pp. 421 - 431
• Main Authors: Khan, Imran, Lee, Kyeong-Lim, Xu, Lianguang, Mesalam, Ayman, Chowdhury, M M R, Joo, Myeong-Don, Ihsan-ul-Haq, Mirza, Bushra, Kong, Il-Keun
• Format: Journal Article
• Language: English
• Published: England Bioscientifica Ltd 01.04.2017
• Subjects: Animals; Cattle; Embryo, Mammalian - cytology; Embryo, Mammalian - drug effects; Embryo, Mammalian - metabolism; Embryonic Development - drug effects; Female; Fertilization in Vitro - drug effects; Gene Expression Regulation, Developmental - drug effects; Heat Stress Disorders - prevention & control; Hot Temperature - adverse effects; HSP70 Heat-Shock Proteins - metabolism; Oocytes - cytology; Oocytes - drug effects; Oocytes - metabolism; Withanolides - chemistry; Withanolides - pharmacology
• ISSN: 1470-1626; 1741-7899
• DOI: 10.1530/REP-16-0530

Heat stress has large effects on reproduction including conception rate in cattle. In this study, we examined the effects of coagulansin-A (coa-A), a steroidal lactone, on acquired thermo tolerance during in vitro production of bovine embryos. Oocytes were incubated in in vitro maturation (IVM) media with or without coa-A at two different temperatures, 40.5˚C and 42˚C, for 20 h. The treatment of coa-A significantly improved blastocyst development only at 40.5˚C (P < 0.05). Interestingly, immunofluorescence analysis demonstrated that coa-A induced heat shock protein 70 (HSP70) and phosphatidylinositol-3-kinase (PI3K), but significantly attenuated nuclear factor kappa B (NF-κB) and cyclooxygenase-2 (COX2). To determine the expression patterns of related genes at the transcription level, qRT-PCR was performed. Expression of HSP70 and PI3K was elevated, whereas expression of NF-κB, COX2 and inducible nitric oxide synthase (iNOS) was significantly (P < 0.05) downregulated in the coa-A-treated group compared with the control group. Moreover, pro-apoptotic genes were downregulated, and antiapoptic genes were upregulated in the coa-A group. We also counted the total cell number and apoptotic nuclei at the blastocyst and found that more cell numbers (143.1 ± 1.5) and less apoptotic damages (6.4 ± 0.5) in the coa-A treatment group comparing to control group (131.4 ± 2.0 and 10.8 ± 0.5), indicating the enhanced embryo quality. In conclusion, our results demonstrate that the coa-A not only improved the blastocyst development in vitro but also increased their resistance to heat stress condition through induction of HSP70/PI3K.