[Frontiers in Bioscience E5, 591-601, January 1, 2013]

Gestational protein restriction affects trophoblast differentiation

Haijun Gao1, Uma Yallampalli1, Chandra Yallampalli1

1Department of Obstetrics and Gynecology, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555-1062, USA


1. Abstract
2. Introduction
3. Materials and methods
3.1. Animals
3.2. DNA extraction from fetal extraembryonic membrane and sex determination
3.3. RNA extraction and RT-PCR
3.4. Quantitative real-time PCR
3.5. Analysis of amino acids in maternal plasma
3.6. Statistical analysis
4. Results
4.1. Weights of junctional and labyrinth zones
4.2. Expressions of marker genes for trophoblast stem cells in JZ were increased by protein restriction
4.3. Expressions of marker genes for spongiotrophoblast cells in JZ was decreased by protein restriction
4.4. Expression of marker gene for trophoblast giant cells in JZ was decreased by protein restriction
4.5. Expressions of marker genes for glycogen cells in JZ were not affected by protein restriction
4.6. Expressions of marker genes for syncytiotrophoblast cells in LZ were not changed by protein restriction
4.7. Expression of marker gene for sinusoidal trophoblast giant cells in LZ was reduced by protein restriction
5. Discussion
6. Acknowledgement
7. References


Whether and how gestational protein restriction (PR) affects placental development and function remain unknown. To test the hypothesis that PR can affect trophoblast differentiation in mid-and late pregnancy, rats were fed a 20% or an isocaloric 6% protein diet from Day 1 to 14 or 18 of pregnancy and effects of PR on trophoblast differentiation were determined by changes in expressions of marker gene(s) for trophoblast lineages. At Day 18 of pregnancy, PR increased expressions of Esrrb, Id1 and Id2 (trophoblast stem cell markers), decreased expressions of Ascl2 (spongiotrophblast cell marker) and Prl2c1 (trophoblast giant cell marker), but did not alter expressions of Gjb3 and Pcdh12 (glycogen cell markers) in the junctional zone (JZ). In the labyrinth zone (LZ), PR did not change expressions of Prl2b1 (trophoblast giant cell marker), Gcm1 and Syna (syncytiotrophoblast cell markers), but decrease expression of Ctsq (sinusoidal trophoblast giant cell marker). These results indicate that PR impairs the differentiation of trophoblast stem cell into spongiotrophoblast and trophoblast giant cells in JZ, and formation of sinusoidal trophoblast giant cells in LZ.