A comparison in concentration of heat shock proteins (HSP) 70 and 90 on chorionic villi of human placenta in normal pregnancies and in missed miscarriages

Purpose: To investigate the role of heat shock protein (HSP) on the chorionic villi of human placenta! cells and to compare the concentration of placental HSP70 & 90 in term deliveries and in missed miscarriages. Materials and Methods: Fifty products of conception from women who experienced first trimester missed miscarriage and 50 placentas from women who gave birth at term were studied. An immunohistochemical investigation was carried out with which we marked the localization of heat shock proteins 70 and 90 on the syncytiotrophoblastic, cytotrophoblastic, stromal and blood vessel cells, using specific antibodies which can detect the presence of those proteins on light microscopy. We compared their expression with the normal placental tissue of term pregnancies and with material acquired from first trimester missed miscarriages. An indirect immunoperoxidase method was applied using polyclonal antibodies against HSP70 and HSP90 on formalin-fixed paraffin-embedded tissues. Results: Expression of HSP90B was increased in chorionic villi of first trimester missed miscarriages concerning syncytiotrophoblasts, cytotrophoblasts, vessel and stroma cells compared to full-term placentas. There was a statistically significant increase of HSP90A expression in chorionic villi of first trimester missed miscarriages, concerning only the cytotrophoblast cells, compared to full-term placentas. Expression of HSP70 cognate protein was significantly increased in chorionic villi of first trimester missed miscarriages, concerning syncytiotrophoblastic cells only, compared to full-term placentas. Finally, HSP70 inducible protein was significantly increased in chorionic villi of first trimester missed miscarriages concerning syncytiotrophoblasts, cytotrophoblasts, vessel and stroma cells compared to full-term placentas. Conclusions: The results of the present study have sufficiently shown that there is an increase of HSP70 & 90 expression in chorionic villi of first trimester missed miscarriages compared to full-term placentas and this increase may have an important implication on the miscarriage process