Expression of integrin β3 and osteopontin in endometrium of patients with adenomyosis

Objective To investigate the expression of integrin β3 and osteopontin(OPN) in eutopic and ectopic endometrium of adenomyosis. Methods From January 2007 to July 2008, the endometrium specimens were collected from 43 patients with adenomyosis undergoing hysterectomy in Peking University First Hospital. Eutopic endometrium were 11 in proliferative phase and 32 in secretory phase (18 cases in mid-secretory phase) were collected. Ectopic endometriums were also collected. In the mean time, it was chosen 41 cases with pure subserous uterine myoma or cervical intraepithelial neoplasia (CIN) Ⅱ-Ⅲ treated by hysterectomy as controls including 12 endometrium in proliferative phase and 29 endometrium in secretory phase (19 cases in mid-secretory phase). The expression of Integrin β3 subunit and OPN in the endometrium were assessed by immunohistochemical staining and quantitative real-time polymerase chain reaction. Results (1)Immunohistochemical staining showed that positive staining of integrin β3 and OPN were present predominantly in eutopic and ectopic endometrial glandular epithelium. There was significant different protein expression of integrin β3 and OPN, which were 1.6±0.8 and 1.7±0.7 in eutopic endometrium,1.7±0.7 and 1.8±0.9 in ectopic endometrium,2.1±0.9 and 2.0±0.9 in control endometrium (P<0.05). The protein expression of integrin β3 and OPN in eutopic endometrium of adenomyosis in the proliferative phase(0.8±0.4 and 0.7±0.3) were remarkably lower than those of the secretory phase(1.8±0.8 and 1.9±0.8,P<0.01). The protein expression of integrin β3 and OPN in the endometrium of controls in the proliferative phase(1.0±0.4 and 1.0±0.4) were significantly lower than those of the secretory phase(2.5±0.7 and 2.5±0.7)(P=0.000). In the mid-secretory phase, the protein expression of integrin β3(2.0±0.9) and OPN (2.1±0.8)in eutopic endometrium of adenomyosis were significantly lower than that of control endometrium(2.7±0.5 and 2.7±0.7)(P<0.01). (2)The mRNA expression level of integrin β and OPN in eutopic and ectopic endometrium were assessed by quantitative real-time PCR(result was shown by median index). It was observed that integrin β3 mRNA and OPN mRNA were significantly lower in the eutopic endometrium of adenomyosis (4.69 and 4.23), when compared with ectopic endometrium(7.96 and 14.84)and controls (13.47 and 17.40) (P<0.05). Eutopic endometrium had higher mRNA expression of integrin β and OPN mRNA in the secretory phase (5.54 and 11.40) than that in the proliferative phase(2.69 and 3.30) (P<0.01).The mRNA expression level of integrin β and OPN of control endometrium in the proliferative phase (3.12 and 4.75)were significantly lower than that in the secretory phase(19.94 and 21.00, P=0.000). The mRNA expression of integrin β and OPN were 10.10 and 14.34 in the mid-secretory phase, which were significantly lower than 21.50 and 24.18 in control endometrium(P<0.05). Conclusions High expression of integrin β3 and OPN in ectopic endometrium of adenomyosis may cause endometriotic lesions; abnormal expression of integrin β3 and OPN in the endometrium of adenomyosis during the implantation window may contribute to infertility in some patients.