The expression of Heat Shock Protein 70 in the placental tissue with preeclampsia
OBJECTIVE: Placental ischemia caused by abnormal trophoblastic invasion to spiral arteries, immunologic intolerance and inflammatory change explain etiology of preeclampsia. As a consequence, inflammatory cells are released and they induce oxidative stress contributing to endothelial dysfunction and endothelial cell injury. Also apoptosis is closely related to preeclampsia in recent finding that placental ischemia contributes to increased apoptotic activity. Heat shock protein 70 (Hsp70) is a stress-induced protein and this protein can be a specific marker for this ischemic and apoptotic circumstance, preeclampsia. Therefore we compared immunohistochemical expression of Hsp70 in normotensive and preeclampsia pregnancies. METHODS: Placenta tissue were obtained from twenty four women complicated by mild and severe preeclampsia, twelve each and from twelve normotensive women right after delivery. Cryosection was immunostained with 1:50 Hsp70 first antibody and the expression of Hsp70 was observed in syncytiotrophoblast, cytotrophoblast, intravillous endothelial cells, extravillous trophoblast in basal layer and decidual cell. And according to the intensity of immunostaining, we compared these three groups. Western blot analysis was performed and the quantification and comparison of Hsp70 were done in placental tissue among the three group of patients. RESULTS: All groups demonstrated positive immunostaining for Hsp70 in cytoplasm of placental cells. But the intensity of immunostaining showed no statistical differences among three groups. The result of Western blot analysis resulted in no differences. CONCLUSION: In other words, the expression of Hsp70 in preeclampsia and normotensive pregnancies demonstrated no differences. This cannot define the oxidative stress as the pathophysiology of preeclampsia and proapoptotic activity in preeclampsia correlated with Hsp70. Since preeclampsia is complicated disease, combination of other Hsp and mediators as cytokines can be used in the future study for better understanding of preeclampsia.
preeclampsia, heat shock protein 70, placenta
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