CLARITY reveals dynamics of ovarian follicular architecture and vasculature in three-dimensions

Sci Rep. 2017 Mar 23:7:44810. doi: 10.1038/srep44810.

Abstract

Optimal distribution of heterogeneous organelles and cell types within an organ is essential for physiological processes. Unique for the ovary, hormonally regulated folliculogenesis, ovulation, luteal formation/regression and associated vasculature changes lead to tissue remodeling during each reproductive cycle. Using the CLARITY approach and marker immunostaining, we identified individual follicles and corpora lutea in intact ovaries. Monitoring lifetime changes in follicle populations showed age-dependent decreases in total follicles and percentages of advanced follicles. Follicle development from primordial to preovulatory stage was characterized by 3 × 105-fold increases in volume, decreases in roundness, and decreased clustering of same stage follicles. Construction of follicle-vasculature relationship maps indicated age- and gonadotropin-dependent increases in vasculature and branching surrounding follicles. Heterozygous mutant mice with deletion of hypoxia-response element in the vascular endothelial growth factor A (VEGFA) promoter showed defective ovarian vasculature and decreased ovulatory responses. Unilateral intrabursal injection of axitinib, an inhibitor of VEGF receptors, retarded neo-angiogenesis that was associated with defective ovulation in treated ovaries. Our approach uncovers unique features of ovarian architecture and essential roles of vasculature in organizing follicles to allow future studies on normal and diseased human ovaries. Similar approaches could also reveal roles of neo-angiogenesis during embryonic development and tumorigenesis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Axitinib
  • Corpus Luteum / cytology
  • Corpus Luteum / diagnostic imaging
  • Corpus Luteum / growth & development
  • Corpus Luteum / metabolism
  • Female
  • Fluorescent Antibody Technique
  • Imaging, Three-Dimensional* / methods
  • Imidazoles / pharmacology
  • Indazoles / pharmacology
  • Mice
  • Microvessels / diagnostic imaging*
  • Microvessels / drug effects
  • Microvessels / pathology
  • Mutation
  • Ovarian Follicle / blood supply*
  • Ovarian Follicle / diagnostic imaging*
  • Ovarian Follicle / growth & development
  • Ovarian Follicle / metabolism
  • Ovary / blood supply
  • Ovary / diagnostic imaging
  • Ovary / metabolism
  • Promoter Regions, Genetic
  • Protein Kinase Inhibitors / pharmacology
  • Receptors, Vascular Endothelial Growth Factor / antagonists & inhibitors
  • Receptors, Vascular Endothelial Growth Factor / metabolism
  • Vascular Endothelial Growth Factor A / genetics
  • Vascular Endothelial Growth Factor A / metabolism

Substances

  • Imidazoles
  • Indazoles
  • Protein Kinase Inhibitors
  • Vascular Endothelial Growth Factor A
  • Axitinib
  • Receptors, Vascular Endothelial Growth Factor