Relationship between ultrastructural features with the expression of connexin 43 in the uterine junction zone and pathogenesis of adenomyosis

Objective To investigate the relationship between the ultrastructural features combined with the expression of connexin ( Cx43 ) protein in uterine junction zone and pathogenesis of adenomyosis.Methods From Nov. 2008 to Nov. 2009, 30 patients with adenomyosis (including 14 cases with proliferative endometrium and 16 cases with secretory endometrium) as study group matched with 30 women with cervical intraepithelial neoplasia (GIN) Ⅲ treated by hysterectomy as control group were enrolled in this study in Affiliated Hospital to Inner Mongolia Medical College. The expression of Cx43 in uterine junction zone of patients with adenomyosis was detected by immunohistochemisty staining. The ultrastucture of eutopic endometrium, uterine junction zone and outer 1/3 myometrium in both groups without history of dilatation and curettage, C-section and uterine surgery were observed by using transmission electron microscopy. Results ( 1 )The expression of Cx43 in proliferative and secretroy uterine junction zone were 0.133 ±0.018 and 0.137 ± 0.021 in study group and 0.154 ±0.016 and 0.141 ±0.018 in control group,which reached statistical difference (P ＜0.05). However, it didn't show significant expression of Cx43 between proliferative and secretory uterine junction zone in study or control group ( P ＞ 0.05 ). The expression of Cx43 in proliferative and secretory of eutopic endometrium of 0.067 ± 0.017 and 0.062 ± 0142 in study group were significantly lower than 0.094 ±0.005 and 0.080 ±0.005 in control group. It didn't show statistical difference of Cx43 expression between proliferative and secretroy eutopic endometrium in both group. The expression Cx43 in outer myometrium of proliferative phase were 0.184 ± 0.022 in study group and 0.188 ± 0.028 in control group, which did not show significant difference (P ＞0.05). It also did not exhibit statistical difference of Cx43 expression in outer myometrium of secretory phase (0.178 ± 0.022,0.191 ± 0.025,P ＞0.05). (2) Morphological changes: the area of uterine smooth muscle cells of the uterine junction zone of (24. 3 ± 1.6) μm2 in study group were significantly increased than (21.8 ±2.0)μm2 in control group (P ＜ 0.01 ). The length of the cell membrane dense plaques of (1.07 ± 0. 17 )μm in study group was significantly increased than (0.71 ±0.07) μm in control group (P ＜0.01 ). The myocytes exhibited cellular hypertrophy and disordered arrangement and fewer caveolae. There was cylindrical and dentate, chromatin margination, more heterochromatin in which muscle cells of nuclear surface of the uterine junction zone. Less cytoplasmic myofilaments and more intermediate filaments. Mitochondria were increased,the volume increased significantly vacuolization. The rough endoplasmic reticulum and Golgi apparatus were more prominent. Otherewise, mast cells and fibroblasts were close and glandular epithelial cells showed desmosome connection which villus thickening and dense. All features were more prominent at the junctional zone. Conclusions The down-regulation of Cx43 expression and ultrastructure changes in the junction zone might play an important role in pathogenesis of adenomyosis. Key words: Endometriosis;  Gap junctions;  Connexin 43;  Microscopy, electron, transmission