Heat shock protein-70 and 4-hydroxy-2-nonenal adducts in human placental villous tissue of normotensive, preeclamptic and intrauterine growth restricted pregnancies.
OBJECTIVE
The purpose of this study was to compare immunohistochemical expression of heat shock protein-70 (hsp70), a marker for oxidative stress, and 4-hydroxy-2-nonenal adducts (HNE), a marker for lipid peroxidation, in placental villous tissue of normotensive, preeclampsia, and intrauterine growth restricted (IUGR) pregnancies.


METHODS
Placentas were collected and flash frozen in liquid nitrogen after delivery from normotensive pregnancies (n=5), and pregnancies complicated by preeclampsia (n=5), IUGR (n=5), and preeclampsia plus IUGR (n=4). Cryosections were cut and immunostained with polyclonal anti-hsp70 and monoclonal anti-HNE antibodies using Vectastain Elite ABC kit. Normal rabbit serum or mouse IgG were used as negative controls. Three independent observers, blinded to identity of tissue, examined each slide to identify cellular localization and intensity of the immunostaining. Western blot analysis and scanning densitometry were used to quantify and compare the amount of hsp70 and HNE adducts present in tissue homogenates.


RESULTS
Positive immunostaining for both antibodies was observed in cytoplasm of syncytiotrophoblasts, extravillous trophoblasts, vascular smooth muscle, and endothelial cells for all groups. Expression of hsp70 and HNE adducts was reported as observers' mean stained intensity. Overall, kappa showed good agreement between observers. Immunostaining intensity was similar in all tissue types for each group with the exception that immunostaining was significantly more intense in the vascular endothelium of the preeclamptic group for HNE adducts (P=.02) and significantly less intense in the IUGR group for hsp70 (P=.013). Scanning densitometric analysis of the Western blots showed no significant difference in total hsp70 and HNE adducts expression in all 4 tissue groups.


CONCLUSIONS
Immunohistochemistry showed local changes for oxidative stress and lipid peroxidation in the vascular endothelium from placentas of preeclamptic and IUGR pregnancies. However, these changes were masked when studying tissue homogenates.
Hnat
Michael D
MD
Department of Obstetrics and Gynecology, University of Cincinnati, College of Medicine, Cincinnati, OH, USA.
Meadows
Juliana W
JW
Brockman
Diane E
DE
Pitzer
Brad
B
Lyall
Fiona
F
Myatt
Leslie
L
D000447:Aldehydes / Q000378:metabolism*; D015153:Blotting, Western; D002824:Chorionic Villi / Q000378:metabolism*; D003720:Densitometry; D005260:Female; D005317:Fetal Growth Retardation / Q000378:metabolism*; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D015227:Lipid Peroxidation / Q000502:physiology; D018384:Oxidative Stress / Q000502:physiology; D011225:Pre-Eclampsia / Q000378:metabolism*; D011247:Pregnancy
D000447:Aldehydes; D018840:HSP70 Heat-Shock Proteins; C027576:4-hydroxy-2-nonenal