Ohlsson R, Falck P, Hellström M, Lindahl P, Boström H, Franklin G, Ahrlund-Richter L, Pollard J, Soriano P, Betsholtz C
Department of Animal Development & Genetics, Uppsala University, Norbyvägen 18A, Uppsala, S-752 36, Sweden.
Dev Biol. 1999 Aug 1;212(1):124-36. doi: 10.1006/dbio.1999.9306.
PDGFB is a growth factor which is vital for the completion of normal prenatal development. In this study, we report the phenotypic analysis of placentas from mouse conceptuses that lack a functional PDGFB or PDGFRbeta gene. Placentas of both types of mutant exhibit changes in the labyrinthine layer, including dilated embryonic blood vessels and reduced numbers of both pericytes and trophoblasts. These changes are seen from embryonic day (E) 13.5, which coincides with the upregulation of PDGFB mRNA levels in normal placentas. By E17, modifications in shape, size, and number of the fetal blood vessels in the mutant placentas cause an abnormal ratio of the surface areas between the fetal and the maternal blood vessels in the labyrinthine layer. Our data suggest that PDGFB acts locally to contribute to the development of the labyrinthine layer of the fetal placenta and the formation of a proper nutrient-waste exchange system during fetal development. We point out that the roles of PDGFB/Rbeta signaling in the placenta may be analogous to those in the developing kidney, by controlling pericytes in the labyrinthine layer and mesangial cells in the kidney.
血小板源性生长因子B（PDGFB）是一种生长因子，对正常产前发育的完成至关重要。在本研究中，我们报告了来自缺乏功能性PDGFB或血小板源性生长因子受体β（PDGFRβ）基因的小鼠胚胎的胎盘的表型分析。两种类型突变体的胎盘在迷路层均表现出变化，包括胚胎血管扩张以及周细胞和滋养层细胞数量减少。这些变化在胚胎第（E）13.5天即可观察到，这与正常胎盘PDGFB mRNA水平的上调相一致。到E17时，突变体胎盘胎儿血管的形状、大小和数量的改变导致迷路层胎儿与母体血管表面积的比例异常。我们的数据表明，PDGFB在局部发挥作用，有助于胎儿胎盘迷路层的发育以及胎儿发育过程中适当的营养物质 - 废物交换系统的形成。我们指出，PDGFB/Rβ信号在胎盘中的作用可能与在发育中的肾脏中的作用类似，通过控制迷路层中的周细胞和肾脏中的系膜细胞来实现。
