Expression of matrix metalloproteinases and their inhibitors at the feto-maternal interface in unruptured ectopic tubal pregnancy

Ectopic pregnancy and epithelial to mesenchymal transition: is there a link?

Ectopic pregnancy (EP) is defined as the implantation of an embryo outside of the uterus and is a leading cause of first trimester maternal mortality and morbidity. This article discusses a possible role for epithelial to mesenchymal transition in the pathogenesis of EP, given the notable similarity of protein expression between the two processes.

Expression of matrix metalloproteinases and their inhibitors at the implantation site in ampullary ectopic pregnancies

OBJECTIVE

This study investigated the qualitative and semi-quantitative expression of metalloproteinases (MMP) and their tissue inhibitors (TIMP) in trophoblastic tissue during ampullary ectopic pregnancies and correlated that expression with the degree of tubal invasion.

STUDY DESIGN

It is a prospective study that included 34 patients diagnosed with ampullary tubal pregnancy who underwent salpingectomy. A histological evaluation of the depth of trophoblastic invasion in the tubes obtained was performed. Subsequently, the expression of the MMP-2, MMP-9, MMP-14, TIMP-1, TIMP-2 and TIMP-3 markers was qualitatively and semi-quantitatively evaluated by indirect immunohistochemistry. In addition, the degree of trophoblastic invasion was correlated with the expression of each marker and with the metalloproteinase/inhibitor ratios.

RESULTS

MMP-2 (11.2 %; 3.6-17.9) was the marker with greater expression at the implantation site, both in the qualitative and semi-quantitative assessment, while MMP-9 (2.23 %; 0.2-5.4) and TIMP-3 (2.53 %; 0.1-15.3) were only weakly expressed.

CONCLUSION

There was wide variation in expression among the markers and metalloproteinase/inhibitor ratios studied compared to the degrees of invasion.

From mice to women and back again: causalities and clues for Chlamydia-induced tubal ectopic pregnancy

OBJECTIVE

To provide an overview of knockout mouse models that have pathological tubal phenotypes after Chlamydia muridarum infection, discuss factors and pathological processes that contribute to inflammation, summarize data on tubal transport and progression of tubal implantation from studies in humans and animal models, and highlight research questions in the field.

DESIGN

A search of the relevant literature using PubMed and other online tools.

SETTING

University-based preclinical and clinical research laboratories.

PATIENT(S)

Women with tubal ectopic pregnancy after Chlamydia trachomatis infection.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Critical review of the literature.

RESULT(S)

Chlamydia trachomatis infection poses a major threat to human reproduction. Biological and epidemiological evidence suggests that progression of Chlamydia infection causes intense and persistent inflammation, injury, and scarring in the fallopian tube, leading to a substantially increased risk of ectopic pregnancy and infertility. The main targets of Chlamydia infection are epithelial cells lining the mucosal surface, which play a central role in host immune responses and pathophysiology. Tubal phenotypes at the cellular level in mutant mice appear to reflect alterations in the balance between inflammatory mediator and factor deficiency. While studies in mice infected with Chlamydia muridarum have provided insight into potential inflammatory mediators linked to fallopian tube pathology, it is unclear how inflammation induced by Chlamydia infection prevents or retards normal tubal transport and causes embryo implantation in the fallopian tube.

CONCLUSION(S)

Given the similarities in the tubal physiology of humans and rodents, knockout mouse models can be used to study certain aspects of tubal functions, such as gamete transport and early embryo implantation. Elucidation of the exact molecular mechanisms of immune and inflammatory responses caused by Chlamydia infection in human fallopian tubal cells in vitro and understanding how Chlamydia infection affects tubal transport and implantation in animal studies in vivo may explain how Chlamydia trachomatis infection drives inflammation and develops the tubal pathology in women with tubal ectopic pregnancy.