The Joint Annual Scientific Meetings of the Endocrine Society of Australia and the Society for Reproductive Biology 2018

Can hyperspectral microscopy detect metabolic variance in the cumulus oocyte complex and predict oocyte quality? (#394)

Cheow Yuen (Tiffany) Tan 1 , Sanam Mustafa 1 , Hannah M Brown 1 , Jeremy G Thompson 1 , Kylie R Dunning 1
  1. Adelaide Medical School, Robinson Research Institute, ARC Centre of Excellence for Nanoscale of BioPhotonics & Institute of Photonics and Advanced Sensing, University of Adelaide, Adelaide, SA, Australia

Despite its wide-spread use, the success rate of assisted reproductive technologies (ART) is less than 20%. The ability of an embryo to result in a live birth is dependent of the quality of the gametes, in particular the oocyte. Thus, the development of a non-invasive tool to segregate oocytes with better developmental potential would likely improve ART success rate. During development and maturation, the oocyte and its surrounding cumulus cells have a high metabolic rate for the production of ATP: necessary for oocyte developmental competence. Autofluorescence generated by endogenous fluorophores as a result of cellular metabolism especially NAD(P)H and FAD, can be used to predict metabolic state of cells. Hyperspectral imaging captures hundreds to thousands of spectra instead of single spectrum using multiple emission wavelengths, including near-infrared, making it an alternative to metabolomics through non-invasively assessing intracellular fluorophores. This provides the capability to measure the metabolic heterogeneity between and within cells. Hyperspectral imaging was recently shown to be capable of discriminating between cancer cells of varying survival rate. In order to show that hyperspectral imaging of cumulus oocyte complexes (COCs) can be a predictive of oocyte quality, we used well-characterised metabolic inhibitors during in vitro maturation (IVM) that are known to negatively impact oocyte quality. COCs underwent IVM in the presence or absence of 2-Deoxy-D-Glucose to block glycolysis; Carbonyl cyanide 4-(trifluoromethoxy) phenylhydrozone as a potent uncoupler of oxidative phosphorylation or etomoxir an inhibitor of β-oxidation. Following IVM (14h), metabolic heterogeneity of COCs was assessed by 40-channel hyperspectral microscopy. Preliminary results show that hyperspectral imaging of COCs in the presence of all metabolic inhibitors revealed drastic shifts in spectral profile compared to control. Advanced autofluorescence microscopy such as hyperspectral imaging may be a useful tool in assessing oocyte quality prior to fertilisation in order to improve the success rate of ARTs.