Caveolin-1 in human preeclamptic placentas

CASTRO-PARODI MAURICIO; ABAN CYNTIA; MARTINEZ, NORA; HERLAX, VANESA; MATE, SABINA; FARINA MARIANA; DAMIANO ALICIA E

Mar del Plata

Simposio; VI LatinAmerican Symposium on Maternal-Fetal Interaction & Placenta; 2015

Placenta Association of the Americas- Grupo Latinoamericano de placenta

Caveolin-1 is a raft-associated protein involved in many cellular events as cell differentiation. It is thought that caveolin-1 may play an important role in the negative regulation of the cell cycle, retarding mitosis to halt proliferation. Emerging data establishes that disturbances in trophoblast differentiation have been related to pathological conditions such as preeclampsia. Unlike the situation reported in other differentiated cells, normal syncyalization process was associated with a reduction in the number of caveolae, and a decreased expression of caveolin-1. Is is known that lipid rafts are distinct regions of the membrane rich in sphingolipids and cholesterol. In preeclamtic placentas, we have previously found an increase in sphingomyelin in the apical membranes of syncytiorophoblast without changes in cholesterol amount. However, if these changes affect the expression of caveolin-1 was not investigated yet. OBJECTIVE: To study expression and localization of caveolin-1 in preeclamptic placentas. METHODS: This study was approved by the ethics committee of the Hospital Nacional Dr. Prof. Alejandro Posadas, Argentina and written consent was obtained from the patients. The expression of caveolin-1 in normal (n=8) and preeclamptic (n=8) placentas was determined by RT-PCR, Western Blot and immunohistochemistry. RESULTS: Western blots experiments showed a significantly decrease of caveolin-1 protein in preeclamptic placentas compared to normal ones. However, RT-PCR experiments showed no differences between normal and preeclampic placentas at transcriptional levels. In normal placenta, caveolin-1 localized in the apical membrane of syncytiotrophoblast and in the endothelium. However, in preeclamptic placentas, caveolin-1 expression was almost undetectable. CONCLUSION: Our findings suggest that caveolin-1 was almost undetectable in preeclamptic placentas. Although in normal placenta, the reduction in caveolin-1 may simply be a feature of the loss of lateral cell membranes following cell fusion in preeclamptic placentas the marked decreased of this protein may be associated to failures in the syncyalization process.