Chicco 2018 MiP2018a

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Adam J Chicco
Maternal aging increases granulosa cell mitochondrial ROS release and reduces oocyte OXPHOS-linked respiration: implications for embryo development.

Link: MiP2018

Chicco AJ, Obediat Y, Catandi GD, Carnevale EM, Chen T (2018)

Event: MiP2018

COST Action MitoEAGLE

Accumulating evidence indicates that an inability of oocyte mitochondria to meet the energy demands of maturation, fertilization, and embryo development contributes to infertility, chromosomal abnormalities and poor assisted reproduction outcomes [1]. This is particularly relevant in the context of maternal aging, where a loss of oocyte mitochondrial content is thought to limit oxidative phosphorylation (OXPHOS) capacity secondary to reductions in mtDNA content or replication [2]. However, our understanding of oocyte and embryo energy metabolism has been limited by technical challenges of sample paucity, and so is based largely on indirect estimates of mitochondrial capacity/content and metabolite analyses. To overcome this limitation, our team developed a miniaturized metabolic multi-sensor capable of real-time monitoring of oxygen consumption and glycolytic flux (glucose, lactate and pH) in single oocytes and embryos. Using this new technology in bovine samples, we characterized the time-course of metabolic changes that occur from oocyte maturation to the blastocyst stage, demonstrating a progressive increase in the utilization of glycolysis over OXPHOS to support energy demands during these stages of development. In equine subjects, we found that oocyte OXPHOS rates decline with maternal age, but with inconsistent loss of maximal (CCCP-induced) respiratory capacity, suggesting a possible age-related shift in metabolic substrate utilization. In parallel studies of equine granulosa cell metabolism using high-resolution respirometry and fluorometry, we found that maternal aging does not impair OXPHOS capacity, but increases release of mitochondria-derived reactive oxygen species (ROS), consistent with evidence that follicular ROS compromises oocyte function and fertilization potential in human aging [3]. These results provide the basis for ongoing efforts to establish new methodology and instrumentation for integrative metabolic monitoring of oocyte and embryo development that enables scientific and therapeutic advances in human reproductive fitness and assisted reproduction outcomes.


Bioblast editor: Plangger M, Kandolf G O2k-Network Lab: US CO Fort Collins Chicco AJ


Labels: MiParea: Respiration  Pathology: Aging;senescence 

Organism: Horse  Tissue;cell: Genital 


Coupling state: OXPHOS, ET 

HRR: Oxygraph-2k, O2k-Fluorometer 


Affiliations

Chicco AJ(1,3), Obediat Y(2,3), Catandi GD(1), Carnevale EM(1), Chen T(2,3)

  1. College Veterinary Medicine Biomedical Sciences
  2. Dept Electrical Computer Engineering
  3. School Biomedical Engineering, Colorado State Univ, Fort Collins, CO, USA. - adam.chicco@colostate.edu

References

  1. Dumollard R, Duchen M, Carroll J (2007) The role of mitochondrial function in the oocyte and embryo. Curr Top Dev Biol 77:21-49.
  2. Zhang D, Keilty D, Zhang ZF, Chian RC (2017) Mitochondria in oocyte aging: current understanding. Facts Views Vis Obgyn 9:29-38.
  3. Attaran M, Pasqualotto E, Falcone T, Goldberg JM, Miller KF, Agarwal A, Sharma RK (2000) The effect of follicular fluid reactive oxygen species on the outcome of in vitro fertilization. Int J Fertil Womens Med 45:314-20.