Pathak Madhulika, Vani Venkatappa, Sharma Surendra, Seshagiri Polani B
Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, India.
Department of Pediatrics, Women and Infants Hospital of Rhode Island, Brown University, Providence, Rhode Island, USA.
Reproduction. 2021 Feb;161(2):123-133. doi: 10.1530/REP-20-0376.
Mammalian blastocyst hatching is a critically indispensable process for successful implantation. One of the major challenges in IVF clinics is to achieve superior embryonic development with intrinsically potent hatching-competent blastocyst. However, the molecular regulation of hatching phenomenon is poorly understood. In this study, we examined the expression and function of one of the cytokines, IL-1β during blastocyst hatching in the mouse. In particular, the expression of IL-1β (Interleukin-1β), IL-1ra (Interleukin-1 receptor antagonist) and their functional receptor IL-1rt1 (Interleukin 1 receptor type-1) in morulae, zona intact- and hatched-blastocysts was studied. Supplementation of IL-1β to cultured embryos accelerated blastocyst development with improved hatching (treated: 89.6 ± 3.6% vs untreated: 65.4 ± 4.1%). When embryos were treated with IL-1ra, blastocyst hatching was decreased (treated: 28.8 ± 3.1% vs untreated: 67.5 ± 3.8%). Moreover, IL-1β and IL-1ra influenced the expression of hatching enzymes viz., implantation serine proteases (ISP1 and ISP2). While IL-1β increased the embryonic mRNA expression of ISPs (Isp1: 2-4; Isp2: 9- to 11-fold), IL-1ra decreased expression. The protein localization studies revealed increased nuclear presence predominantly of ISP 2 in IL-1β-treated blastocysts. This is the first report to show the functional significance of embryonic IL-1β in regulating hatching-associated proteases, particularly ISP2. These findings have implications in our understanding of molecular regulation of blastocyst hatching and implantation failure in other species including humans.
哺乳动物囊胚孵化是成功着床的关键必备过程。体外受精诊所面临的主要挑战之一是利用具有内在孵化能力的强大囊胚实现卓越的胚胎发育。然而，人们对孵化现象的分子调控了解甚少。在本研究中，我们检测了细胞因子之一白细胞介素-1β（IL-1β）在小鼠囊胚孵化过程中的表达及功能。特别研究了桑葚胚、完整透明带囊胚和孵化囊胚中IL-1β（白细胞介素-1β）、IL-1ra（白细胞介素-1受体拮抗剂）及其功能性受体IL-1rt1（白细胞介素1受体1型）的表达。向培养的胚胎补充IL-1β可加速囊胚发育并改善孵化情况（处理组：89.6±3.6%，未处理组：65.4±4.1%）。用IL-1ra处理胚胎后，囊胚孵化率降低（处理组：28.8±3.1%，未处理组：67.5±3.8%）。此外，IL-1β和IL-1ra影响孵化酶即着床丝氨酸蛋白酶（ISP1和ISP2）的表达。IL-1β增加了胚胎中ISP的mRNA表达（Isp1：2至4倍；Isp2：9至11倍），而IL-1ra降低了表达。蛋白质定位研究显示，IL-1β处理的囊胚中主要是ISP 2的核内存在增加。这是首份表明胚胎IL-1β在调节与孵化相关蛋白酶尤其是ISP2方面具有功能意义的报告。这些发现有助于我们理解包括人类在内的其他物种中囊胚孵化和着床失败的分子调控。
