During pregnancy the previously poor vasodilatory response of uterine artery endothelium (UA Endo) to agonists such as ATP is now enhanced through a greatly prolonged Capacitative Ca2+ entry (CCE), and this results in enhanced activation of eNOS. Since P-UA Endo's enhanced function now approaches that of other vessels, increases in uterine blood flow also occur. In preeclamptic (PE) subjects who often show elevated VEGF and TNF, this sustained Ca2+ response to ATP is also lost, along with a blunting of NO output. VEGF165 signals through ERK-1/2 to cause transient inhibitory phosphorylation of the Gap junction protein, Cx43 and loss of adapted CCE Ca2+ signaling. U0126 blockade can reverse this 0x43 phosphorylation and rescue pregnancy adapted Ca2+ burst function on subsequent challenge with ATP. Brief TNF mediated Src activation also directly phosphorylates CX43 on Tyr 265, causing Cx43 inhibition that is reversible by PP2. Long term.Src activation can also promote Tyr phosphorylation of ZO-1 and disassociation from Cx43, so causing Gap junction disassembly and 0x43 movement away from cell contact points and loss of pregnancy adapted CCE function. To that end:
Specific Aim 1 investigates the hypothesis that in P-UAEC, HUVEC and HUAEC that VEGF165 or TNF can mediate the dose dependent inhibition of sustained Ca2+ signaling through ERK or Src mediated direct CX43 protein phosphorylation.
Specific Aim 2 investigates the further hypothesis that these same VEGF or TNF mediated inhibitory effects in P-UAEC, HUVEC and HUAEC may also promote ZO-1 protein dissociation from CX43 wherever we see chronic activation of the Src pathway.
Specific Aim 3 translates Aims 1 and 2 back to intact vessels (UA Endo - pregnant sheep and HUV Endo or HUA Endo - normal human cords);by testing the hypothesis that the inhibitory actions of VEGF and TNF on endothelial Ca2+ observed in Aims 1 and 2 causes corresponding inhibition of NO production in vivo.
Specific Aim 4 tests the hypothesis that together even low doses of VEGF and TNF synergize to inhibit normal endothelial function in all vessels studied through the co-activation of Src and ERK-1/2 inhibitory pathways. A new therapy to treat PE may result from these studies.

Public Health Relevance

Preeclampsia is a disease of endothelial failure effecting 8-20% of the population, depending on ethnicity. We believe we have working model of the mechanisms underlying endothelial failure in preeclamptic pregnancy, and we propose to test that model. Our long term goal is that such studies could provide a proof of principle for targeting of new and novel therapies to treat this otherwise devastating disease.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Program Projects (P01)
Project #
2P01HD038843-11A1
Application #
8616120
Study Section
Special Emphasis Panel (ZHD1-DSR-Z (MR))
Project Start
Project End
Budget Start
2013-08-15
Budget End
2014-05-31
Support Year
11
Fiscal Year
2013
Total Cost
$197,069
Indirect Cost
$63,898
Name
University of Wisconsin Madison
Department
Type
DUNS #
161202122
City
Madison
State
WI
Country
United States
Zip Code
53715
Boeldt, Derek S; Hankes, Amanda C; Alvarez, Roxanne E et al. (2014) Pregnancy programming and preeclampsia: identifying a human endothelial model to study pregnancy-adapted endothelial function and endothelial adaptive failure in preeclamptic subjects. Adv Exp Med Biol 814:27-47
Zhao, Ying-Jie; Zou, Qing-Yun; Li, Yan et al. (2014) Expression of G-protein subunit ?-14 is increased in human placentas from preeclamptic pregnancies. J Histochem Cytochem 62:347-54
Jiang, Yi-Zhou; Li, Yan; Wang, Kai et al. (2014) Distinct roles of HIF1A in endothelial adaptations to physiological and ambient oxygen. Mol Cell Endocrinol 391:60-7
Li, Hui-Hui; Zhao, Ying-Jie; Li, Yan et al. (2014) Estradiol 17? and its metabolites stimulate cell proliferation and antagonize ascorbic acid-suppressed cell proliferation in human ovarian cancer cells. Reprod Sci 21:102-11
Chen, Dong-Bao; Zheng, Jing (2014) Regulation of placental angiogenesis. Microcirculation 21:15-25
Ampey, Bryan C; Morschauser, Timothy J; Lampe, Paul D et al. (2014) Gap junction regulation of vascular tone: implications of modulatory intercellular communication during gestation. Adv Exp Med Biol 814:117-32
Boeldt, Derek S; Grummer, Mary A; Magness, Ronald R et al. (2014) Altered VEGF-stimulated Ca2+ signaling in part underlies pregnancy-adapted eNOS activity in UAEC. J Endocrinol 223:1-11
Schreier, David A; Hacker, Timothy A; Hunter, Kendall et al. (2014) Impact of increased hematocrit on right ventricular afterload in response to chronic hypoxia. J Appl Physiol (1985) 117:833-9
Morschauser, Timothy J; Ramadoss, Jayanth; Koch, Jill M et al. (2014) Local effects of pregnancy on connexin proteins that mediate Ca2+-associated uterine endothelial NO synthesis. Hypertension 63:589-94
Giakoumopoulos, M; Golos, T G (2013) Embryonic stem cell-derived trophoblast differentiation: a comparative review of the biology, function, and signaling mechanisms. J Endocrinol 216:R33-45

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