title: Chronic Protein Restriction in Mice Impacts Placental Function and Maternal Body Weight before Fetal Growth.
abstract: Mechanisms of resource allocation are essential for maternal and fetal survival, particularly when the availability of nutrients is limited. We investigated the responses of feto-placental development to maternal chronic protein malnutrition to test the hypothesis that maternal low protein diet produces differential growth restriction of placental and fetal tissues, and adaptive changes in the placenta that may mitigate impacts on fetal growth. C57BL/6J female mice were fed either a low-protein diet (6% protein) or control isocaloric diet (20% protein). On embryonic days E10.5, 17.5 and 18.5 tissue samples were prepared for morphometric, histological and quantitative RT-PCR analyses, which included markers of trophoblast cell subtypes. Potential endocrine adaptations were assessed by the expression of Prolactin-related hormone genes. In the low protein group, placenta weight was significantly lower at E10.5, followed by reduction of maternal weight at E17.5, while the fetuses became significantly lighter no earlier than at E18.5. Fetal head at E18.5 in the low protein group, though smaller than controls, was larger than expected for body size. The relative size and shape of the cranial vault and the flexion of the cranial base was affected by E17.5 and more severely by E18.5. The junctional zone, a placenta layer rich in endocrine and energy storing glycogen cells, was smaller in low protein placentas as well as the expression of Pcdh12, a marker of glycogen trophoblast cells. Placental hormone gene Prl3a1 was altered in response to low protein diet: expression was elevated at E17.5 when fetuses were still growing normally, but dropped sharply by E18.5 in parallel with the slowing of fetal growth. This model suggests that nutrients are preferentially allocated to sustain fetal and brain growth and suggests the placenta as a nutrient sensor in early gestation with a role in mitigating impacts of poor maternal nutrition on fetal growth.
authors.affiliation: Instituto de Genética Veterinaria, CCT-CONICET, La Plata, Argentina.|de Ciencias Naturales y Museo, UNLP, La Plata, Argentina.
authors.forename: Paula N
authors.initials: PN
authors.lastname: Gonzalez
authors.affiliation: Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, and the Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Gasperowicz
authors.affiliation: Instituto de Genética Veterinaria, CCT-CONICET, La Plata, Argentina.|de Ciencias Naturales y Museo, UNLP, La Plata, Argentina.
authors.forename: Jimena
authors.initials: J
authors.lastname: Barbeito-Andrés
authors.affiliation: Department Biochemistry & Molecular Biology, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Natasha
authors.initials: N
authors.lastname: Klenin
authors.affiliation: Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, and the Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada.|Department Biochemistry & Molecular Biology, University of Calgary, Calgary, Alberta, Canada.
authors.forename: James C
authors.initials: JC
authors.lastname: Cross
authors.affiliation: Department of Cell Biology and Anatomy, Alberta Children's Hospital Research Institute, and McCaig Institute for Bone and Joint Health. University of Calgary, Calgary, Alberta, Canada.
authors.forename: Benedikt
authors.initials: B
authors.lastname: Hallgrímsson
mesh_terms: D000818:Animals; D001835:Body Weight; D001921:Brain / Q000502:physiology; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D018753:Diet, Protein-Restricted; D047108:Embryonic Development; D005260:Female; D047109:Fetal Development / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010920:Placenta / Q000502:physiology*; D010926:Placental Hormones / Q000235:genetics / Q000378:metabolism; D011247:Pregnancy; D011388:Prolactin / Q000235:genetics / Q000378:metabolism; D000091363:Protocadherins; D060888:Real-Time Polymerase Chain Reaction; D055114:X-Ray Microtomography
chemical_list: D015820:Cadherins; C504542:Pcdh12 protein, mouse; D010926:Placental Hormones; D000091363:Protocadherins; D011388:Prolactin