Different pattern of interleukin-1 beta-(IL-1 beta), interleukin-1 receptor antagonist- (IL-1ra) and interleukin-1 receptor type I- (IL-1R tI) mRNA-expression in single preimplantation mouse embryos at various developmental stages.
The interleukin-1 (IL-1) system has been shown to play an important role in human and murine embryo implantation. Recent studies have documented immunohistochemical evidence of interleukin-1 beta (IL--1 beta), interleukin-1 receptor antagonist (IL-1ra) and interleukin-1 receptor type I (IL-1R tI) in human preimplantation embryos and protein levels of interleukin-1 alpha (IL-1 alpha), IL-1 beta and IL1ra in human preimplantation embryo culture fluid have been correlated with successful implantation and pregnancy. Our aim in this study was to detect IL-1 beta, Il-1ra and Il-1R tI mRNA in single preimplantation mouse embryos and to describe the frequency of positive mRNA-expression at different developmental stages. B6C3F1-mice, 12 weeks old were pregnant mare serum gonadotropin (PMSG)/human chorionic gonadotropin (hCG)-stimulated and mated. Animals were sacrificed at day 0.5, and zygotes were flushed from the tubes and cultured in HAMs-F10 medium. 2-cell- (2C-), 8-cell- (8C-), morula- (M-), early blastocyst- (EB-) and hatching blastocyst- (HB-) stage embryos were examined by one round of reverse transcriptase (RT) followed by two rounds of polymerase chain reaction (PCR) carried out on individual mouse embryos for beta-actin (internal standard), IL-1 beta, IL-1ra and IL-1R tI-mRNAs. The frequencies of positive mRNA-expressions were as follows (2C/8C/M/EB/HB); beta-actin: 91/96/100/100/98%; IL-1b: 0/0/2.5/6.25/19; IL-1ra; 0/5/30/41/74% and IL-1R tI: 0/0/10/20/25%. The incidence of IL-1ra mRNA expression increased with developmental stage. IL-1ra mRNA seems to be expressed in a very high percentage (74%) of embryos near the time of implantation, whereas the percentage of IL-1 beta-mRNA positive embryos is surprisingly low (19%).
Kruessel
J S
JS
Department of Gynecology and Obstetrics, Stanford University School of Medicine, Palo Alto, California 94304, USA. krussel@leland.stanford.edu
Huang
H Y
HY
Wen
Y
Y
Kloodt
A R
AR
Bielfeld
P
P
Polan
M L
ML
D000818:Animals; D001755:Blastocyst / Q000378:metabolism*; D046508:Culture Techniques / Q000379:methods; D017931:DNA Primers; D005314:Embryonic and Fetal Development; D005260:Female; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1 / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D012333:RNA, Messenger / Q000032:analysis; D017472:Receptors, Interleukin-1 / Q000037:antagonists & inhibitors* / Q000096:biosynthesis* / Q000235:genetics; D053573:Receptors, Interleukin-1 Type I; D012795:Sialoglycoproteins / Q000096:biosynthesis* / Q000235:genetics
D017931:DNA Primers; C507763:IL1RN protein, human; C507764:Il1rn protein, mouse; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1; D012333:RNA, Messenger; D017472:Receptors, Interleukin-1; D053573:Receptors, Interleukin-1 Type I; D012795:Sialoglycoproteins