Saadeldin Islam M, Koo Ok Jae, Kang Jung Taek, Kwon Dae Kee, Park Sol Ji, Kim Su Jin, Moon Joon Ho, Oh Hyun Ju, Jang Goo, Lee Byeong Chun
Department of Theriogenology and Biotechnology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, 151-742, Korea.
Reprod Fertil Dev. 2012;24(5):656-68. doi: 10.1071/RD11118.
Kisspeptin (Kp) is best known as a multifunctional peptide with roles in reproduction, the cardiovascular system and cancer. In the present study the expression of kisspeptin hierarchy elements (KISS1, GNRH1 and LHB) and their receptors (KISS1R, GNRHR and LHCGR, respectively) in porcine ovary and in cumulus-oocyte complexes (COCs) were investigated, as were its effects on the in vitro maturation (IVM) of oocytes and their subsequent ability to sustain preimplantation embryo competence after parthenogenetic electrical activation. Kp system elements were expressed and affected IVM of oocytes when maturation medium was supplemented with 10(-6)M Kp. Oocyte maturation, maternal gene expression (MOS, GDF9 and BMP15), blastocyst formation rate, blastocyst hatching and blastocyst total cell count were all significantly increased when oocytes were matured in medium containing Kp compared with the control group (without Kp). A Kp antagonist (p234) at 4×10(-6)M interfered with this hierarchy but did not influence the threshold effect of gonadotrophins on oocyte maturation. FSH was critical and permissive to Kp action on COCs by increasing the relative expression of KISS1R. In contrast, Kp significantly increased apoptosis, the expression of pro-apoptotic gene, BAK1, and suppressed trophoblast outgrowths from hatched blastocysts cultured on feeder cells. The present study provides the first functional evidence of the Kp hierarchy in porcine COCs and its role in enhancing oocyte maturation and subsequent developmental competence in an autocrine-paracrine manner. However, Kp supplementation may have a harmful impact on cultured hatched blastocysts reflecting systemic or local regulation during the critical early period of embryonic development.
亲吻素（Kp）是一种多功能肽，在生殖、心血管系统和癌症中发挥作用，最为人所知。在本研究中，研究了亲吻素层级元件（KISS1、GNRH1和LHB）及其受体（分别为KISS1R、GNRHR和LHCGR）在猪卵巢和卵丘-卵母细胞复合体（COC）中的表达，以及其对卵母细胞体外成熟（IVM）的影响，及其对孤雌电激活后维持植入前胚胎能力的后续作用。当成熟培养基中添加10⁻⁶M Kp时，Kp系统元件表达并影响卵母细胞的IVM。与对照组（无Kp）相比，当卵母细胞在含Kp的培养基中成熟时，卵母细胞成熟、母源基因表达（MOS、GDF9和BMP15）、囊胚形成率、囊胚孵化和囊胚总细胞数均显著增加。4×10⁻⁶M的Kp拮抗剂（p234）干扰了这一层级，但不影响促性腺激素对卵母细胞成熟的阈值效应。FSH通过增加KISS1R的相对表达对Kp作用于COC起关键和允许作用。相反，Kp显著增加凋亡、促凋亡基因BAK1的表达，并抑制饲养层细胞上培养的孵化囊胚的滋养层生长。本研究提供了猪COC中Kp层级的首个功能证据，及其以自分泌-旁分泌方式增强卵母细胞成熟和后续发育能力的作用。然而，补充Kp可能对培养的孵化囊胚有有害影响，反映了胚胎发育关键早期的全身或局部调节。
