title: From mice to women and back again: causalities and clues for Chlamydia-induced tubal ectopic pregnancy.
abstract: 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.
  
  
  METHODS
  A search of the relevant literature using PubMed and other online tools.
  
  
  METHODS
  University-based preclinical and clinical research laboratories.
  
  
  METHODS
  Women with tubal ectopic pregnancy after Chlamydia trachomatis infection.
  
  
  METHODS
  None.
  
  
  METHODS
  Critical review of the literature.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Physiology/Endocrinology, Institute of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden. ruijin.shao@fysiologi.gu.se
authors.forename: Ruijin
authors.initials: R
authors.lastname: Shao
authors.forename: Xiaoqin
authors.initials: X
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Elisabet
authors.initials: E
authors.lastname: Stener-Victorin
authors.forename: Carina
authors.initials: C
authors.lastname: Mallard
authors.forename: Mats
authors.initials: M
authors.lastname: Brännström
authors.forename: Håkan
authors.initials: H
authors.lastname: Billig
mesh_terms: D000818:Animals; D002690:Chlamydia Infections / Q000150:complications / Q000276:immunology / Q000382:microbiology*; D023502:Chlamydia muridarum / Q000276:immunology / Q000472:pathogenicity*; D002692:Chlamydia trachomatis / Q000276:immunology / Q000472:pathogenicity*; D004195:Disease Models, Animal; D004847:Epithelial Cells / Q000276:immunology / Q000382:microbiology; D005187:Fallopian Tubes / Q000276:immunology / Q000382:microbiology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D011247:Pregnancy; D011271:Pregnancy, Ectopic / Q000235:genetics / Q000276:immunology / Q000382:microbiology* / Q000503:physiopathology; D018570:Risk Assessment; D012307:Risk Factors