Expression and Protein Content of IGF-I and IGF-I Receptor in Placentas from Small, Adequate and Large for Gestational Age Newborns

Abstract

In humans, a direct relationship between IGF-I cord blood levels and birth weight has been demonstrated. To determine the placental IGF-I, IGF-II and IGF-IR mRNA and protein contents in full-term pregnancies from appropriate for gestational age (AGA), small for gestational age (SGA) and large for gestational age (LGA) newborns, we studied the placentas from 35 AGA, 30 SGA and 28 LGA pregnancies. The IGF-I, IGF-II and IGF-I receptor (IGF-IR) placental mRNA and protein contents were determined in the basal and chorionic plates of the placenta. IGF1 and IGF1R mRNA was higher in SGA compared to AGA and LGA placentas and lower in LGA compared with AGA placentas. In addition, a higher protein content of IGF-I and IGF-IR was observed in SGA compared with AGA and LGA placentas and lower contents in LGA compared with AGA placentas. These results suggest that the higher IGF-I and IGF-IR contents observed in SGA placentas and the lower contents observed in LGA placentas compared with AGA placentas may be influencing human fetal growth.

Correlation of Insulin-Like Growth Factor-I and -II Concentrations at Birth Measured by Mass Spectrometry and Growth from Birth to Two Months

“…This may affect nutrient availability to the fetus and subsequently reduce growth parameters and IGF-I concentrations. IGF-I and -II are both expressed in chorionic and basal plates of the placenta [44], and thus may play a key role in regulating placentation.…”

Ecogeographical associations between climate and human body composition: Analyses based on anthropometry and skinfolds

“…Such plasticity may arise through a variety of different mechanisms, including variable expression of hormones such as IGF1 (Iniguez et al, 2006(Iniguez et al, , 2010, which plays a key role in regulating linear growth, or transgenerational effects of variability in maternal phenotype (e.g., uterine volume). Some effects may involve epigenetic marks on the genome, giving rise to life-course effects on gene expression (Youngson and Whitelaw, 2008).…”

The severe short stature in two siblings with a heterozygous IGF1 mutation is not caused by a dominant negative effect of the putative truncated protein

“…Some studies reported increased expression of IGF-I and IGF1R in placentas from small for gestational age (SGA) newborns compared with appropriate for gestational age (AGA) newborns [39][40][41], while other studies showed decreased or equal expression. Inconsistencies could be due to differences in the selection criteria for IUGR, length of gestation and the methodology used [40,42].…”

“…Some studies reported increased expression of IGF-I and IGF1R in placentas from small for gestational age (SGA) newborns compared with appropriate for gestational age (AGA) newborns [39][40][41], while other studies showed decreased or equal expression. Inconsistencies could be due to differences in the selection criteria for IUGR, length of gestation and the methodology used [40,42]. Based on the observation that birth length and childhood height of case III-1 is 1-2 SD lower than of her mother and our previous observations in a family with an IGF1R mutation [38], in which the proband's length was much more affected than in her mother, who did not inherit the mutation maternally, we hypothesize that IGF-I and IGF1R play an important role in normal placental function and consequently in intrauterine growth.…”