Paradoxical effects of inhibition of Δ14-reductase and Δ7-reductase on porcine oocyte maturation and subsequent embryo development after parthenogenetic activation
Sanghoon Lee , Dabin Cha , Jun-Xue Jin , Geon A. Kim , Byeong Chun Lee
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引用次数: 0
Abstract
Follicular fluid-derived meiosis-activating sterol (FF-MAS), an intermediate in the cholesterol biosynthesis pathway, plays a crucial role in the meiotic resumption of mammalian oocytes. Maintaining a high concentration of FF-MAS in vitro is challenging; therefore, AY9944 A-7, an inhibitor of Δ14-reductase [which converts FF-MAS to testis meiosis-activating sterol (T-MAS)] and Δ7-reductase (which converts T-MAS to cholesterol), has been used to enhance oocyte maturation. This study examined the effects of various concentrations (0, 10, 20, and 40 μM) of AY9944 A-7 on porcine oocyte maturation and subsequent embryo development. Results indicate that treatment with 10 and 20 μM AY9944 A-7 during in vitro maturation (IVM) enhanced oocyte nuclear maturation, with 10 μM significantly increasing the transcript expression of oocyte maturation-related genes. However, blastocyst formation rates significantly decreased in oocytes treated with AY9944 A-7 concentrations above 10 μM. To explore these unexpected findings, the study evaluated the effects of AY9944 A-7 on lipid content in oocytes and the sonic hedgehog (SHH) signaling pathway in subsequent parthenogenetic embryos. A concentration-dependent decrease in oocyte lipid content was observed following AY9944 A-7 treatment. Additionally, transcripts of SHH signaling pathway genes were detected in preimplantation-stage parthenogenetic embryos, with reduced expression in the 10 μM AY9944 A-7-treated group. Taken together, AY9944 A-7 supplementation during porcine IVM enhanced oocyte maturation by accumulating FF-MAS, but subsequent embryo development was impaired due to cholesterol deficiency, potentially mediated by SHH signaling downregulation.
期刊介绍:
Theriogenology provides an international forum for researchers, clinicians, and industry professionals in animal reproductive biology. This acclaimed journal publishes articles on a wide range of topics in reproductive and developmental biology, of domestic mammal, avian, and aquatic species as well as wild species which are the object of veterinary care in research or conservation programs.