Pigment epithelium-derived factor (PEDF): a novel trophoblast-derived factor limiting feto-placental angiogenesis in late pregnancy

Abstract

The rapidly expanding feto-placental vasculature needs tight control by paracrine and endocrine mechanisms. Here, we focused on paracrine influence by trophoblast, the placental epithelium. We aimed to identify differences in regulation of feto-placental angiogenesis in early versus late pregnancy. To this end, the effect of conditioned media (CM) from early and late pregnancy human trophoblast was tested on network formation, migration and proliferation of human feto-placental endothelial cells. Only CM of late pregnancy trophoblast reduced network formation and migration. Screening of trophoblast transcriptome for anti-angiogenic candidates identified pigment epithelium-derived factor (PEDF) with higher expression and protein secretion in late pregnancy trophoblast. Addition of a PEDF-neutralizing antibody restored the anti-angiogenic effect of CM from late pregnancy trophoblast. Notably, human recombinant PEDF reduced network formation only in combination with VEGF. Also in the CAM assay, the combination of PEDF with VEGF reduced branching of vessels below control levels. Analysis of phosphorylation of ERK1/2 and FAK, two key players in VEGF-induced proliferation and migration, revealed that PEDF altered VEGF signaling, while PEDF alone did not affect phosphorylation of ERK1/2 and FAK. These data suggest that the trophoblast-derived anti-angiogenic molecule PEDF is involved in restricting growth and expansion of the feto-placental endothelium predominantly in late pregnancy and targets to modulate the intracellular effect of VEGF.Electronic supplementary materialThe online version of this article (doi:10.1007/s10456-016-9513-x) contains supplementary material, which is available to authorized users.

Consensus guidelines for the use and interpretation of angiogenesis assays

“…It is therefore crucial to understand the full potential of these bioassays during their specific applications. These assays have been instrumental in the study of vascular biology in growth and development [6–8] but also play a key role in the design, development, and evaluation of drugs that positively or negatively modulate vessel function for the treatment of many diseases [9–11]. Some examples of where the use of such bioassays has been imperative are: (1) the development of angiostatic drugs for the treatment of cancer, ocular diseases, and other pathologic conditions where angiogenesis is implicated and also angiogenic treatment strategies in ischemic cardiovascular disease [12, 13], (2) screening of natural anti-angiogenic compounds [14], (3) the efforts to design combination therapies including angiogenesis inhibitors [15–20], (4) the unraveling of mechanisms regulating lymphangiogenesis [21, 22], (5) the interrelationship of angiogenesis and immunity [23–25], (6) the development of imaging as diagnostic strategy [26], (7) the study of drug resistance mechanisms [27–29], (8) development of compounds and strategies for the revascularization of ischemic injuries [30, 31], and (9) to improve the vascular fitness in aging vessels [32, 33].…”

Pigment epithelium‑derived factor facilitates NLRP3 inflammasome activation through downregulating cytidine monophosphate kinase 2: A potential treatment strategy for missed abortion

“…Pigment epithelium-derived factor (PEDF) is a multifunctional paracrine protein that is a member of the serpin superfamily (14). PEDF is widely expressed in various tissues, including the placenta and trophoblast, and exerts anti-angiogenic effects in the late stages of pregnancy (15,16). Previous studies have revealed that activation of the NLRP3 inflammasome was inhibited by PEDF in ischemic cardiomyocytes through its phospholipaseA2/nutrin/patarin-like phospholipase domain-containing 2 PEDF receptor (PEDFR) (17).…”

Conditioned medium from primary cytotrophoblasts, primary placenta-derived mesenchymal stem cells, or placental tissue promoted HUVECs angiogenesis in vitro

“…After being incubated for 15 hours, the capillary-like structures were observed under a light microscope, and pictures of 3-5 visual elds/well were taken. The total length of the tubular structure was analyzed by using the Angiogenesis Analyzer plug-in for ImageJ software (NIH, USA) [36,37].…”