Pregnancy-dependent Expression of Leukaemia Inhibitory Factor (LIF), LIF Receptor-β and Interleukin-6 (IL-6) Messenger Ribonucleic Acids in the Porcine Female Reproductive Tract

240

155

Implantation is an intricately timed event necessary in the process of viviparous birth that allows mammals to nourish and protect their young during early development. Human implantation begins when the blastocyst both assumes a fixed position in the uterus and establishes a more intimate relationship with the endometrium. Due to the impracticalities of studying implantation in humans, animal models are necessary to decipher the molecular and mechanical events of this process. This review will discuss the differences in implantation between different animal models and describe how these differences can be utilized to investigate discrete implantation stages. In addition, factors that have been shown to be involved in implantation in the human and other various animal models including growth factors, cytokines, modulators of cell adhesion, and developmental factors will be discussed, and examples from each will be given.

Section: Leukemia Inhibitory Factor (Lif)mentioning

confidence: 61%

Animal models of implantation

Lee

DeMayo²

2004

240

155

“…LE, uterine luminal epithelium; GE, uterine glandular epithelium; E 2 , 17b-estradiol; TNF, tumor necrosis factor a; LIF, leukemia inhibitory factor; NK cells, natural killer cells; IL6R, receptor of interleukin 6; LIFR, receptor of leukemia inhibitory factor; IL1R1, interleukin 1 receptor type I; PGR, progesterone receptor; ESR, estrogen receptor; PTGER2, PGE 2 receptor; LPAR3, lysophosphatidic acid receptor; TGFB1, transforming growth factor b; VEGFA, vascular endothelial growth factor; IGF1, insulin-like growth factor 1; FGF7, fibroblast growth factor 7; HOXA10, Homeobox A10; NFKB, nuclear factor kappa B; SPP1, secreted phosphoprotein 1; SLA I, swine leukocyte antigens class I; B2M, b 2 microglobulin. (Ross et al 2003), IL6 (Modrić et al 2000), PGE 2 and PGF 2a (Waclawik & Ziecik 2007), indicating that the embryo induces inflammatory pathways in the endometrium (Fig. 2).…”

Section: Nk Cellsmentioning

confidence: 92%

“…During early pregnancy the endometrium also produces another proinflammatory cytokine, LIF (Modrić et al 2000). LIF is involved in controlling the uterine receptivity in other species and is essential for implantation in mice (Paria et al 2002).…”

Section: Nk Cellsmentioning

confidence: 99%

Novel insights into the mechanisms of pregnancy establishment: regulation of prostaglandin synthesis and signaling in the pig

Wacławik

2011

Ovarian progesterone induces essential changes leading to a temporary state of uterine receptivity for conceptus implantation. Estrogens secreted by the porcine conceptus on days 11 and 12 of pregnancy provide the initial signal for maternal recognition of pregnancy and maintenance of a functional corpus luteum (CL) for continued production of progesterone. As prostaglandins F 2a (PGF 2a ) and E 2 (PGE 2 ) exert opposing actions on the CL, a tight control over their synthesis and secretion is critical either for the initiation of luteolysis or maintenance of pregnancy. One of the supportive mechanisms by which conceptus inhibits luteolysis is changing PG synthesis in favor of luteoprotective PGE 2 . Conceptus PGE 2 could be amplified by PGE 2 feedback loop in the endometrium. In pigs, as in other species, implantation and establishment of pregnancy is associated with upregulation of expression of proinflammatory factors, which include cytokines, growth factors, and lipid mediators. The conceptus produces inflammatory mediators: interferon g and interferon d, interleukins IL1B and IL6, and PGs, which probably activate inflammatory pathways in the endometrium. The endometrium responds to these embryonic signals by enhancing further progesterone-induced uterine receptivity. Understanding the mechanisms of pregnancy establishment is required for translational research to increase reproductive efficiencies and fertility in humans and animals.

“…However, uterine receptivity is regulated only by ovarian P 4 in hamsters (Prasad et al 1960, Orsini & Meyer 1962, Harper et al 1969, Wang et al 2002, 2004, Zhang & Paria 2006. Studies in the mouse, rat, and agricultural species suggest that cytokines and growth factors produced by the uterine cells in response to ovarian steroids help in preimplantation embryo development and implantation (Carson et al 2000, Modric et al 2000. Among the cytokines studied, leukemia inhibitory factor (Lif) has been established as an essential molecule for uterine receptivity and implantation in mice (Stewart et al 1992, Song et al 2000.…”

Section: Introductionmentioning

confidence: 99%

Leukemia inhibitory factor ligand-receptor signaling is important for uterine receptivity and implantation in golden hamsters (Mesocricetus auratus)

Ding¹,

Song²,

Wang³

et al. 2007

Blastocyst implantation occurs in the progesterone-primed uterus of hamsters, but not in mice where the progesterone-primed uterus requires estrogen influence. Leukemia inhibitory factor (Lif), an estrogen-regulated gene in mice, is an absolutely needed cytokine for uterine receptivity and implantation in this species. This study aimed to evaluate the importance of Lif ligand-receptor signaling during uterine receptivity and implantation in hamsters. We investigated whether or not the uterine expression patterns of Lif and its receptors, Lif-r and gp130, during the periimplantation period of pregnancy and its hormonal regulation in the ovariectomized hamster correlate with some of the vital phases of uterine changes during early pregnancy. Uterine Lif, Lif-r, and gp130 mRNA expressions were examined by Northern and in situ hybridization. During the uterine preparatory phase for implantation, Lif, Lif-r, and gp130 were expressed either in the gland, luminal epithelium or both. As the implantation process began, Lif expression was minimal, but Lif-r and gp130 extended to the decidual areas. This decidual expression of Lif-r and gp130 was not dependent on the presence of the embryo since these genes were expressed in the sutureinduced deciduomata. We also observed that, while the uterine Lif was induced by estrogen, Lif-r and gp130 were induced by progesterone in ovariectomized hamsters. Additionally, we show that a Lif antibody when instilled intraluminally on day 3 of pregnancy reduced the number of implantation sites. Taken together, these data suggest that Lif signaling is important for uterine receptivity and implantation in hamsters. Reproduction (2008) 135 41-53