130 Pregnancy-associated glycoprotein profile is altered in twin but not singleton pregnancies after pre-conception diet manipulation.

摘要

Maternal nutritional manipulation during gestation influences birth weight and can have long-lasting effects on the progeny. Maternal nutrition effects before mating on placental function and fetal development remain unknown. Pregnancy-associated glycoproteins (PAGs) secreted by placental binucleate cell are indicators of feto-placental well-being. We examined if pre-mating nutritional manipulation affects placental function and fetal growth. Prolific crossbred (Polypay x Dorset) sheep were assigned to one of three nutritional treatments receiving 100% (control: C; 33 kcal metabolizable energy/kg body weight; n=27), 50% (undernutrition: UN; n=27), or 200% (overnutrition: ON; n=31) of maintenance energy requirements for 21 days before mating. Maternal plasma samples were collected on gestational days (GD) 15, 30, 60, 90, 120, and 140 and assayed for PAG (IDEXX, ELISA assay). Mixed models were used for statistical analyses. Pre-mating nutritional manipulation changed maternal liveweight (C: -103 ± 29; UN: -462 ± 29; ON: +230 ± 25 g/day; P<0.001). Between GD60 and GD120, pre-conceptional nutrition affected PAG (P<0.05) with ON having higher PAG compared to C and UN treatment. Birth type, but not lamb sex, affected PAG concentrations throughout pregnancy (P<0.001), with PAG relative to fetal mass being ~38% lower in twin . singleton pregnancies (P<0.001). Pre-mating nutrition affected PAG throughout pregnancy in twin, but not singleton pregnancies (P<0.05); with ON having higher PAG compared to C and UN treatments. Irrespective of treatment or birth type, PAG increased up to GD120 and declined thereafter. Birth weight was positively associated with PAG across pregnancy regardless of treatment (P<0.001). We demonstrated that a 3-week pre-conceptional overnutrition can increase circulating PAGs, with this effect evident in twin pregnancies. Lower PAGs in twin pregnancies suggest lower placental PAG synthetic/secretory capacity relative to single pregnancies. Further research is needed to elucidate the positive relationship between PAG and birth weight and the mechanism underlying the effect of pre-conceptional nutrition on circulating PAGs.