Abstract
BackgroundAutophagy has been reported to be essential for pre-implantation development and embryo survival. However, its role in placental development and regulation of autophagy during pregnancy remain unclear. The aims of this study were to (1) study autophagy by characterizing changes in levels of beclin-1, DRAM, and LC3B in human placenta throughout gestation; (2) determine whether autophagy is involved in regulation of trophoblast invasion in JEG-3 cells (a choriocarcinoma cell line); (3) examine the effects of reduced oxygen and glucose on the autophagic changes; and (4) investigate the effect of reoxygenation and supplementation of glucose after oxygen-glucose deprivation (OGD) on the autophagic changes in primary cytotrophoblasts obtained from normal term pregnancy.Methodology/Principal FindingsAn analysis of 40 placental samples representing different gestational stages showed (1) no significant differences in beclin-1, DRAM, and LC3B-II levels in placentas between early and mid-gestation, and late gestation with vaginal delivery; (2) placentas from late gestation with cesarean section had lower levels of LC3B-II compared to early and mid-gestation, and late gestation with vaginal delivery; levels of DRAM were also lower compared to placentas from early and mid-gestation; and (3) using explant cultures, villous tissues from early and late gestation had similar rates of autophagic flux under physiological oxygen concentrations. Knockdown of BECN1, DRAM, and LC3B had no effects on viability and invasion activity of JEG-3 cells. On the other hand, OGD caused a significant increase in the levels of LC3B-II in primary cytotrophoblasts, while re-supplementation of oxygen and glucose reduced these changes. Furthermore, there were differential changes in levels of beclin-1, DRAM, and LC3B-II in response to changes in oxygen and glucose levels. Conclusions/SignificanceOur results indicate that autophagy is involved in development of the human placenta and that changes in oxygen and glucose levels participate in regulation of autophagic changes in cytotrophoblast cells.
Highlights
Autophagy is a highly regulated process involving invagination and degradation of cytoplasmic components such as damaged organelles, protein aggregates, and invading organisms through the lysosomal pathway [1]
Given the fact that autophagy plays an important role in early embryo development and in pregnancy complications, the specific objectives of this study are as follows: (1) to study the extent of autophagy by characterizing changes in the levels of beclin-1, LC3B, and DRAM in the human placenta throughout gestation; (2) to ascertain whether autophagy is involved in regulation of trophoblast invasion activity using a choriocarcinoma cell line, JEG-3 cells, as a model; (3) to examine the effect of reduced oxygen and glucose on autophagic changes; and (4) to investigate the effect of reoxygenation and supplementation of glucose on autophagic changes after oxygen-glucose deprivation (OGD) in primary cytotrophoblasts obtained from normal term pregnancy
BECN1, DRAM, and LC3B were consistently expressed in the placentas, though no significant differences in protein levels of these molecules were noted in placentas between early and mid-gestation, and late gestation with vaginal deliveries (VD)
Summary
Autophagy is a highly regulated process involving invagination and degradation of cytoplasmic components such as damaged organelles, protein aggregates, and invading organisms through the lysosomal pathway [1]. The aims of this study were to (1) study autophagy by characterizing changes in levels of beclin-1, DRAM, and LC3B in human placenta throughout gestation; (2) determine whether autophagy is involved in regulation of trophoblast invasion in JEG-3 cells (a choriocarcinoma cell line); (3) examine the effects of reduced oxygen and glucose on the autophagic changes; and (4) investigate the effect of reoxygenation and supplementation of glucose after oxygen-glucose deprivation (OGD) on the autophagic changes in primary cytotrophoblasts obtained from normal term pregnancy. Conclusions/Significance: Our results indicate that autophagy is involved in development of the human placenta and that changes in oxygen and glucose levels participate in regulation of autophagic changes in cytotrophoblast cells
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
