Expression profile of heat shock proteins in placental tissues of patients with preterm prelabor rupture of membranes and spontaneous preterm labor with intact membranes.

PROBLEM: Investigating the stress response in the central cotyledon zone of placental tissue in pregnancies with PPROM, PTB, and at term in labor.

METHOD OF STUDY: Gene expression of Hsp27, Hsp60, Hsp70, Hsp90, and HspBP1 was compared between these particular groups. Correlation between variables including Hsp gene expression in placental tissue and the gestational age at delivery, WBC count at admission, and serum levels of CRP at admission in patients with PPROM and PTB was determined.

RESULTS

Both PPROM and PTB pregnancies were associated with altered Hsp gene expression profile. While PPROM and PTB always induced upregulation of Hsp27 and Hsp60, downregulation of Hsp70 and HspBP1 was present entirely in patients with PPROM. HspBP1 expression profile was also able to differentiate between PPROM and PTB pregnancies. The highest mRNA levels of Hsp60 and Hsp70 were detected in PTB pregnancies with elevated CRP levels at admission. Some of the examined Hsp displayed increased expression with advancing gestational age in both groups (PPROM: Hsp27, Hsp70, and Hsp90; and PTB: Hsp27).

CONCLUSION

Upregulation of Hsp27 is a common phenomenon shared between pregnancies affected with PTB and PPROM. On the other hand, downregulation of Hsp70 and HspBP1 represents a unique feature of PPROM.