title: Epithelial cell protein milk fat globule-epidermal growth factor 8 and human chorionic gonadotropin regulate stromal cell apoptosis in the human endometrium.
abstract: OBJECTIVE
  To study the regulation of apoptosis in human endometrial cells. The specific aims were to determine whether milk fat globule-epidermal growth factor 8 (MFG-E8), a novel endometrial epithelial protein, modulates caspase activation and DNA fragmentation; and to examine whether hCG, an early embryonic product, regulates Bax and Bcl-2 equilibrium, as well as MFG-E8 expression.
  
  
  METHODS
  Primary cultures of human endometrial epithelial cells (EECs) and endometrial stromal cells (ESCs).
  
  
  METHODS
  Academic center.
  
  
  METHODS
  Ovulatory women aged 21-30 years.
  
  
  METHODS
  Treatment with MFG-E8 and hCG.
  
  
  METHODS
  Apoptotic activity was quantified using a luciferase assay. Deoxyribonucleic acid fragmentation was detected by TUNEL assay. Bax, Bcl-2, and MFG-E8 messenger RNA expression levels were determined by quantitative reverse transcription-polymerase chain reaction. Immunocytochemistry was used to establish cell purity and presence of MFG-E8 and hCG-R (receptor) proteins.
  
  
  RESULTS
  Endometrial epithelial cells were cytokeratin(+), vimentin(-), MFG-E8(+), and hCG-R(+), whereas ESC were vimentin(+), cytokeratin(-), MFG-E8(-), and hCG-R(+). Treatment of ESC with MFG-E8 resulted in a 13-fold increase in caspase activity and a 30-fold increase in TUNEL. On the other hand, hCG decreased messenger RNA expression of Bax in ESC.
  
  
  CONCLUSIONS
  Milk fat globule-epidermal growth factor 8 has proapoptotic activity, suggesting participation in endometrial remodeling via an epithelial-stromal cell paracrine effect. Conversely, pregnancy levels of hCG has opposite effects on stromal cells.
authors.affiliation: The Jones Institute for Reproductive Medicine, Department of Obstetrics and Gynecology, Eastern Virginia Medical School, Norfolk, Virginia 23507, USA.
authors.forename: Ryan M
authors.initials: RM
authors.lastname: Riggs
authors.forename: Silvina
authors.initials: S
authors.lastname: Bocca
authors.forename: Sandra
authors.initials: S
authors.lastname: Anderson
authors.forename: Anahi
authors.initials: A
authors.lastname: Franchi
authors.forename: Bhaskara S
authors.initials: BS
authors.lastname: Rhavi
authors.forename: Sergio
authors.initials: S
authors.lastname: Oehninger
mesh_terms: D000328:Adult; D000954:Antigens, Surface / Q000378:metabolism*; D017209:Apoptosis / Q000502:physiology; D020169:Caspases / Q000378:metabolism; D002478:Cells, Cultured; D006063:Chorionic Gonadotropin / Q000378:metabolism*; D004717:Endometrium / Q000166:cytology* / Q000378:metabolism*; D004789:Enzyme Activation; D004847:Epithelial Cells / Q000378:metabolism*; D005260:Female; D006801:Humans; D008894:Milk Proteins / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D017154:Stromal Cells / Q000166:cytology; D055815:Young Adult; D051028:bcl-2-Associated X Protein
chemical_list: D000954:Antigens, Surface; C494826:BAX protein, human; D006063:Chorionic Gonadotropin; C098942:MFGE8 protein, human; D008894:Milk Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; D020169:Caspases