Kim Sue, Lee So Hyun, Kim Ji Hye, Jeong Yeon Woo, Hashem M A, Koo Ok Jae, Park Sun Mi, Lee Eu Gine, Hossein M S, Kang Sung Keun, Lee Byeong Chun, Hwang Woo Suk
Department of Theriogenology and Biotechnology, College of Veterinary Medicine, Seoul National University, Seoul, Korea.
Mol Reprod Dev. 2006 Dec;73(12):1523-30. doi: 10.1002/mrd.20531.
Insulin-like growth factor (IGF)-I is a receptor-mediated autocrine and/or paracrine growth and/or survival factor for mammalian embryo development. It is known to promote the growth and development of mouse preimplantation embryos. The present study was designed to investigate the effects of IGF-I (50 ng/ml), anti-IGF-I receptor antibody (50 ng/ml) and their combination on porcine preimplantation embryo development. Furthermore, the mechanism underlying the embryotropic effects of IGF-I was evaluated by monitoring the incidence of apoptosis and expression of apoptosis-related genes. In both in vitro fertilized (IVF) and somatic cell nuclear transfer (SCNT) embryos, culturing with IGF-I increased the rate of blastocyst formation and this embryotrophic effect was neutralized by culturing with IGF-I along with anti-IGF-I receptor (IGF-IR) antibody. Culturing IVF and SCNT embryos with IGF-I significantly increased the number of total cells in blastocysts and decreased the number of apoptotic nuclei. These effects of IGF-I were also neutralized by culturing with IGF-I along with anti-IGF-IR antibody. Expression of the anti-apoptotic Bcl-2 gene was increased, while expression of the pro-apoptotic Bax was decreased in both IVF and SCNT embryos cultured with IGF-I. In both IVF and SCNT embryos, anti-IGF-IR antibody along with IGF-I neutralized the effect of IGF-I on expression of Bcl-2 and Bax genes. In conclusion, the present study demonstrated that IGF-I through its specific receptors improved the developmental competence of IVF and SCNT embryos by decreasing the incidence of apoptosis and regulating apoptosis-related genes in porcine preimplantation embryos.
胰岛素样生长因子（IGF）-I是一种受体介导的自分泌和/或旁分泌生长和/或存活因子，对哺乳动物胚胎发育起作用。已知它能促进小鼠植入前胚胎的生长和发育。本研究旨在探讨IGF-I（50纳克/毫升）、抗IGF-I受体抗体（50纳克/毫升）及其组合对猪植入前胚胎发育的影响。此外，通过监测细胞凋亡发生率和凋亡相关基因的表达，评估了IGF-I胚胎营养作用的潜在机制。在体外受精（IVF）胚胎和体细胞核移植（SCNT）胚胎中，用IGF-I培养均可提高囊胚形成率，而用IGF-I与抗IGF-I受体（IGF-IR）抗体共同培养可中和这种胚胎营养作用。用IGF-I培养IVF和SCNT胚胎可显著增加囊胚中的总细胞数，并减少凋亡细胞核的数量。IGF-I的这些作用也可通过与抗IGF-IR抗体共同培养IGF-I来中和。在用IGF-I培养的IVF和SCNT胚胎中，抗凋亡Bcl-2基因的表达增加，而促凋亡Bax基因的表达减少。在IVF和SCNT胚胎中，抗IGF-IR抗体与IGF-I共同作用可中和IGF-I对Bcl-2和Bax基因表达的影响。总之，本研究表明，IGF-I通过其特异性受体降低猪植入前胚胎的细胞凋亡发生率并调节凋亡相关基因，从而提高IVF和SCNT胚胎的发育能力。
