A comparison of placental development and endocrine functions between the human and mouse model

Abstract

The placenta plays a key role in pregnancy, mediating exchanges between mother and fetus and maternal tolerance of fetopaternal antigens. In some species, it also produces hormones that ensure the maintenance of gestation and fetal well-being. This unique organ also has considerable potential for use as a model for various aspects of biology. Indeed, the use of transgenic mouse models has greatly improved our understanding of the genetic control of placental development in this species and has opened up new ®elds of investigation in developmental biology. Analogous cell types have been identi®ed among human and murine trophoblasts: proliferative trophoblastic cells, invasive trophoblastic cells and cells differentiating into syncytium, but human and mouse placentas differ in both morphogenesis and endocrine function. Herein, the similarities and differences between the human and mouse models are reviewed, with a view to encouraging caution in the extrapolation of results from one model to the other.

A Randomized Trial of Progesterone in Women with Recurrent Miscarriages

“…[19][20][21][22] We discontinued progesterone at 12 weeks of gestation but consider it unlikely that therapy beyond this time would result in better outcomes; it is well documented that corpus luteal function is replaced by placental production of progesterone before the end of the first trimester. 3 Moreover, among PROMISE participants who had a miscarriage, the median gestation was less than 8 weeks (7.3 weeks in the progesterone group and 7.1 weeks in the placebo group).…”

“…If implantation occurs, the corpus luteum continues to produce progesterone, but between 8 and 12 weeks of gestation, the placenta takes over this role and maintains the pregnancy thereafter. 3 The physiological importance of progesterone in early pregnancy has prompted the performance of several trials to evaluate the effect of progesterone supplementation in the first trimester of pregnancy among women with a history of recurrent miscarriages. A Cochrane review of four small trials showed a significantly lower risk of miscarriages among women who received progesterone than among those who received placebo or no treatment (odds ratio, 0.39; 95% confidence interval [CI], 0.21 to 0.72), but the quality of the four trials was considered to be poor.…”

Estabelecimento de um modelo de gestação complicada por diabetes tipo 1 em camundongos: avaliação do seu impacto sobre o ambiente uterino no início da gestação.

“…iii) invasão e remodelação do endométrio decidualizado e de sua vasculatura pelas células do trofoblasto; iv) estabelecimento da placenta (Revisão em: Georgiades et al, 2002;Malassine et al, 2003). (Bevilacqua, Abrahamsohn, 1988;Revisão em: Cross et al, 1994;Malassine et al, 2003;.…”

“…(Bevilacqua, Abrahamsohn, 1988;Revisão em: Cross et al, 1994;Malassine et al, 2003;. Considerando que a organogênese compreende o período entre o 7º e o 12º dg , grande parte deste processo ocorre enquanto o embrião é nutrido pela placenta corio-vitelínica, enfatizando a sua importância para o desenvolvimento embrionário em camundongos.…”

“…Considerando que a organogênese compreende o período entre o 7º e o 12º dg , grande parte deste processo ocorre enquanto o embrião é nutrido pela placenta corio-vitelínica, enfatizando a sua importância para o desenvolvimento embrionário em camundongos. Por volta do 10-11° dg, a placenta corio-alantóica está fundamentalmente estruturada e ativa, assumindo o papel principal na nutrição do embrião (Revisão em: Malassine et al, 2003).…”