Paradoxical effects of kisspeptin: it enhances oocyte in vitro maturation but has an adverse impact on hatched blastocysts during in vitro culture.
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.
Department of Theriogenology and Biotechnology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, 151-742, Korea.
Islam M
IM
Saadeldin
Ok Jae
OJ
Koo
Jung Taek
JT
Kang
Dae Kee
DK
Kwon
Sol Ji
SJ
Park
Su Jin
SJ
Kim
Joon Ho
JH
Moon
Hyun Ju
HJ
Oh
Goo
G
Jang
Byeong Chun
BC
Lee
D000818:Animals; D001755:Blastocyst / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D002478:Cells, Cultured; D046149:Embryo Culture Techniques; D047108:Embryonic Development / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D005260:Female; D059471:In Vitro Oocyte Maturation Techniques / Q000662:veterinary; D059648:Kisspeptins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D009865:Oocytes / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D009866:Oogenesis / Q000187:drug effects / Q000235:genetics; D010312:Parthenogenesis / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism; D013552:Swine
D059648:Kisspeptins; D043562:Receptors, G-Protein-Coupled