Factors derived from preeclamptic placentas perturb polarity protein PARD-3 expression and distribution in endothelial cells.
OBJECTIVE
This study aimed to examine (1) whether polarity protein partitioning defective-3 (PARD-3) was expressed in endothelial cells (ECs) and contributed to endothelial barrier integrity and (2) whether altered PARD-3 expression and distribution were associated with disturbed endothelial junction protein VE-cadherin expression induced by factors derived from preeclamptic (PE) placentas.


METHODS
PARD-3 and VE-cadherin expressions were examined by immunofluorescent staining and Western blot in confluent ECs and in ECs treated with normal and PE placental conditioned medium (CM). Protein-protein interactions between PARD-3/VE-cadherin, PARD-3/ atypical protein kinase C (aPKCλ), and VE-cadherin/aPKCλ were examined by immuno-precipitation and immunobloting.


RESULTS
Similar to VE-cadherin, PARD-3 is localized at the cell contacts in control ECs. Both PARD-3 and VE-cadherin expressions were markedly reduced in cells treated with PE-CM for 2h, but not in cells treated with normal-CM compared to non-treated controls. Cytosol staining of VE-cadherin and PARD-3 was pronounced in cells after 24h treatment with PE-CM. PARD-3/VE-cadherin and PARD-3/aPKCλ complexes were detected in PE-CM treated cells, but not in untreated control cells and in cells after recovery. In contrast, VE-cadherin/aPKCλ complex was detected in control cells and in cells after recovery, but not in PE-CM treated cells.


CONCLUSIONS
Polarity protein PARD-3 is localized at cell contacts. Factors-derived from PE placentas not only interrupt junction protein VE-cadherin distribution, but also perturb polarity protein PARD-3 expression and distribution in ECs. The results of PARD-3/VE-cadherin and PARD-3/aPKCλ complexes formation in cells treated with placental CM suggest that factors-derived from placenta could interfere both junction protein and polarity protein functions in ECs.
Zhao
Juan
J
Department of Obstetrics and Gynecology, LSUHSC-Shreveport, Shreveport, LA 71130, USA.
Gu
Yang
Y
Fan
Ruping
R
Groome
Lynn J
LJ
Wang
Yuping
Y
D048868:Adaptor Proteins, Signal Transducing; D015703:Antigens, CD / Q000378:metabolism; D015820:Cadherins / Q000378:metabolism; D002199:Capillary Permeability / Q000502:physiology; D018797:Cell Cycle Proteins / Q000378:metabolism*; D016764:Cell Polarity / Q000502:physiology*; D002478:Cells, Cultured; D017077:Culture Media, Conditioned / Q000494:pharmacology; D015536:Down-Regulation / Q000187:drug effects / Q000502:physiology; D042783:Endothelial Cells / Q000166:cytology* / Q000378:metabolism*; D005260:Female; D006801:Humans; D007365:Intercellular Junctions / Q000378:metabolism; D007527:Isoenzymes / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D010920:Placenta / Q000378:metabolism; D011225:Pre-Eclampsia / Q000378:metabolism* / Q000473:pathology*; D011247:Pregnancy; D011493:Protein Kinase C / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D014471:Umbilical Veins / Q000166:cytology; D000099293:Protein Kinase C-lambda; D000099152:Cadherin 5
D048868:Adaptor Proteins, Signal Transducing; D015703:Antigens, CD; D015820:Cadherins; D018797:Cell Cycle Proteins; D017077:Culture Media, Conditioned; D007527:Isoenzymes; D008565:Membrane Proteins; D011493:Protein Kinase C; D000099293:Protein Kinase C-lambda; D000099152:Cadherin 5; C509689:PARD3 protein, human