title: In vitro maturation of human oocytes and cumulus cells using a co-culture three-dimensional collagen gel system.
abstract: BACKGROUND
  Deficiencies remain in the ability of in vitro-matured human oocytes to acquire full developmental competence and give rise to a healthy pregnancy. A clear deficiency of current systems utilizing human oocytes has been the absence of cumulus cells. In the present study, a three-dimensional (3D) co-culture system exploiting an extracellular matrix was developed and compared to conventional methods for its ability to support maturation of human oocytes.
  
  
  RESULTS
  Cumulus cells were embedded into a 3D collagen gel matrix with individual oocytes added to each gel. Oocytes from the same patient cultured in the gel matrix matured to metaphase II at rates similar to those of cumulus-free oocytes cultured in individual microdrops. Following maturation of oocytes and fixation of intact gels, chromatin and cytoskeletal elements were assessed in oocytes and cumulus cells. The activities of the key cell cycle kinases, maturation-promoting factor (MPF) and mitogen-activated protein kinase (MAPK), were compared in oocytes matured under the two culture conditions. Compared with denuded oocytes, co-cultured oocytes exhibited increased MAPK activity, but no difference in MPF levels.
  
  
  CONCLUSIONS
  This work characterizes a novel and efficacious culture system that takes advantage of the unique properties of the extracellular matrix, a 3D microenvironment, and the presence of cumulus cells for maturing human oocytes in vitro.
authors.affiliation: Brigham and Women's Hospital, Harvard Medical School, Department of Obstetrics and Gynecology, Boston, MA 02115, USA.
authors.forename: Catherine M H
authors.initials: CM
authors.lastname: Combelles
authors.forename: Rafael A
authors.initials: RA
authors.lastname: Fissore
authors.forename: David F
authors.initials: DF
authors.lastname: Albertini
authors.forename: Catherine
authors.initials: C
authors.lastname: Racowsky
mesh_terms: D000328:Adult; D002470:Cell Survival; D002478:Cells, Cultured; D002843:Chromatin / Q000235:genetics / Q000648:ultrastructure; D018920:Coculture Techniques / Q000379:methods*; D003094:Collagen; D003599:Cytoskeleton / Q000648:ultrastructure; D005260:Female; D005782:Gels; D006801:Humans; D016200:Maturation-Promoting Factor / Q000378:metabolism; D008677:Metaphase / Q000502:physiology; D008870:Microtubules / Q000648:ultrastructure; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009865:Oocytes / Q000166:cytology / Q000502:physiology*; D006080:Ovarian Follicle / Q000166:cytology*
chemical_list: D002843:Chromatin; D005782:Gels; D003094:Collagen; D016200:Maturation-Promoting Factor; D020928:Mitogen-Activated Protein Kinases