Mol. Hum. Reprod. Advance Access originally published online on January 29, 2004
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Molecular Human Reproduction, Vol. 10, No. 3, pp. 173-179, 2004
© European Society of Human Reproduction and Embryology 2004
Expression and localization of 
vß6 integrin in extraplacental fetal membranes: possible role in human parturition
1Gynaecological Cancer Research Centre, Royal Women’s Hospital, 132 Grattan Street, Carlton,Victoria 3053 and 2Department of Obstetrics and Gynaecology, Mercy Hospital for Women, The University of Melbourne, Victoria, Australia
3 To whom correspondence should be addressed at: Gynaecological Cancer Research Centre, Royal Women’s Hospital, Australia. e-mail: nuzhata{at}unimelb.edu.au
Successful outcome of human parturition is dependent upon extensive remodelling of the extracellular matrix (ECM) of the cervix, uterus and fetal membranes, a process that involves adhesion molecules and is also common in tumour invasion and metastasis. To elucidate the role of integrins in human parturition, this study characterizes the expression of the tumour-associated 
vß6 integrin in human placenta and extraplacental membranes. Immunohistochemical analysis of the placenta and fetal membranes from normal vaginal deliveries (NVD) (n = 10) exhibited strong intensity of staining for vß6 integrin (3 = dark brown) in the epithelial layer of the amnion. Weak immunohistochemical staining of vß6 integrin (1 = pale brown) was detected in the chorion and at the decidual edge. These results were consistent with the immunodetection of vß6 integrin by western blot analysis that showed 4-fold enhanced expression in the amnion compared to chorion of both NVD and term elective caesarean section (CS) deliveries. Even though there was no difference in the extent of immunohistochemical staining of vß6 integrin between the amnion of NVD and CS groups, significantly higher intensity of staining was observed in the NVD amniotic epithelium compared to that of CS (n = 10) (
2 = 10.25, P = 0.0059). Western blot analysis of the fetal membranes showed no differences in the expression of vß6 integrin between the NVD and CS groups. Gelatin zymography demonstrated the presence of pro-matrix metalloprotein-9 (MMP-9) and pro-MMP-2 in the amnion and chorion of NVD, whereas in CS only the presence of pro-MMP-2 was observed. These results suggest that in term pregnancy, human fetal membranes express vß6 integrin and that the expression is significantly higher in amnion compared to chorion. The fact that enhanced expression of vß6 integrin in fetal membranes correlates with the expression of pro-MMP-9 in NVD is consistent with the invasive role of the integrin in cancer and suggests that the molecule may have a proteolytic role in the initiation and progression of labour.
Key words: Key words: amnion/chorion/integrin/parturition/placenta