Decreased expression of activated placental heat shock protein 27 in human and ovine intrauterine growth restriction (1095.15)

Abstract

Intrauterine growth restriction (IUGR) has been documented to have increased placental apoptosis at term. Previous reports from our lab showed apoptosis as an early event in an ovine model of IUGR. Our objective was to determine the expression of active HSP27 in human IUGR placentas near term and to compare its expression to those found in the placenta on an ovine hyperthermia induced model of IUGR. Human placenta tissue samples were collected at term for active HSP27 determination. Pregnant sheep were placed in hyperthermic (HT) conditions to induce IUGR. Compared to controls, IUGR pregnancies showed: 1) reduced activation (1.7‐fold, p<0.009) of HSP27 in the human placenta; 2) smaller placentas (349±21g v. 169±22g; p<0.03) and fetal (2914±201g v. 1718±433g; p<0.03) weights in the ovine IUGR model; 3) Increased placental apoptosis in this model; 4) a 1.8‐fold increase (p<0.005) in active HSP27 in the ovine placenta near term; and 5) localization of active HSP27 to the trophoblast cells of the ovine placenta.We conclude that decreased active HSP27 at term is present when placental apoptosis is increased during IUGR. This could be a factor leading to the decreased placental weight observed during this disease (Supported by NIH grant 7K99HD055054‐02).Grant Funding Source: 7K99HD055054‐02