LMU Munich, Faculty of Medicine, Institute of Anatomy, Chair of Neuroanatomy, Munich, Germany.
LMU Munich, Faculty of Medicine, Institute of Anatomy, Chair of Neuroanatomy, Munich, Germany.
Placenta. 2017 Dec;60:47-53. doi: 10.1016/j.placenta.2017.10.004. Epub 2017 Oct 14.
Placental syncytiotrophoblast is responsible for feto-maternal nutrient exchange during pregnancy. It is assumed that in IUGR, placental dysfunction is crucially bound to compromised stability and function of syncytiotrophoblast, the latter being related to altered proliferation of villous trophoblast. Cell cycle data obtained on conventional thin sections has produced inconsistent results. In the present study we investigated cell cycle markers found in the villous trophoblast using a novel 3D histological quantification method.
We analyzed 40 placentas from IUGR pregnancies and 42 placentas from clinically normal pregnancies by immunohistochemical detection of the cell cycle marker PCNA. Nuclei immuno-positive for PCNA were quantified using 3D microscopy, and the results were compared to corresponding results obtained on conventional thin histological sections. These data did not show any evidence of altered trophoblast proliferation in IUGR, while the density of post-proliferative (i.e. PCNA-negative) trophoblast nuclei was statistically significantly increased in IUGR. The latter could be revealed by 3D topological microscopy, but not by conventional histology of thin sections.
The data of the present study indicate a previously unknown type of regulation of syncytial stability and function, independent of proliferation. We hypothesize that in IUGR, post-proliferative trophoblast nuclei accumulate at the villous surface of peripheral villous branches. This could possibly reflect the presence of an unknown mechanism controlling syncytial function and stability by modulation of syncytial passage time rather than by modulation of proliferative supply.
胎盘合体滋养层负责妊娠期间胎儿-母体营养交换。据推测，在 IUGR 中，胎盘功能障碍与合体滋养层的稳定性和功能受损密切相关，后者与绒毛滋养层增殖改变有关。在常规薄片上获得的细胞周期数据产生了不一致的结果。在本研究中，我们使用新的 3D 组织学定量方法研究了绒毛滋养层中的细胞周期标志物。
我们通过对细胞周期标志物 PCNA 的免疫组织化学检测分析了 40 例 IUGR 妊娠和 42 例临床正常妊娠的胎盘。使用 3D 显微镜对 PCNA 免疫阳性核进行定量，并将结果与常规薄片组织学上获得的相应结果进行比较。这些数据没有显示 IUGR 中绒毛滋养层增殖改变的证据，而 IUGR 中增殖后（即 PCNA 阴性）滋养层核的密度统计学上显著增加。后者可以通过 3D 拓扑显微镜揭示，但不能通过常规的薄片组织学揭示。
本研究的数据表明存在一种以前未知的调节合体稳定性和功能的类型，独立于增殖。我们假设在 IUGR 中，增殖后的滋养层核在周围绒毛分支的绒毛表面积聚。这可能反映了存在一种未知的机制，通过调节合体通过时间而不是通过调节增殖供应来控制合体的功能和稳定性。
