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

IntroductionIntrauterine growth restriction (IUGR) has been documented to increase placental apoptosis at term. HSP27 has been shown to be involved in the control of apoptosis. Our objective is to determine the expression of phosphorylated HSP27 (p-HSP27) in human IUGR, and to determine the role of HSP27 during gestation in an ovine hyperthermia induced model of IUGR.MethodsHuman placenta tissue samples were collected at term to quantify p-HSP27. Pregnant sheep were placed in hyperthermic (HT) conditions to induce IUGR. Placental tissues were collected at 55 (early), 95 (mid-gestation) and 130 (near-term) days gestational age (dGA) to determined phosphorylated and total HSP27 across the development of IUGR.ResultsPhosphorylated HSP27 was significantly reduced in human placenta IUGR compared to controls at term. HSP27 was increased throughout gestation during the development of IUGR in the sheep. P-HSP27 was increased in early gestation (55 dGA), and decreased near term (130 dGA). The near term decrease was localized to the trophoblast cells of the placenta.Discussion and conclusionWe conclude that decreased p-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 IUGR.