Noninvasive autologous mitochondria transport improves the quality and developmental potential of oocytes from aged mice

Objective

To establish an optimized autologous mitochondria transport technique for oocyte–aging rescue, which minimizes both the patient’s pains and the damage to oocytes.

Design

Experimental laboratory study.

Setting

Laboratory.

Animal(s)

Institute of Cancer Research mice.

Intervention(s)

The murine umbilical cord mesenchymal stem cells were isolated from the female pup and cryopreserved. After the female aged, its germinal vesicle (GV) oocytes were collected and treated to weaken the zona pellucida. Its autologous umbilical cord mesenchymal stem cells were induced into granulosa cells (iGCs). The zona-weakened GV oocytes were aggregated with iGCs into iGC-oocyte complexes. Then, these complexes were cultured in growth-differentiation factor 9-containing media for 3 days. Next, they were subjected to in vitro maturation and fertilization. Presumptive zygotes were cultured for 24 hours, and the cleaved 2-cell embryos were selected for embryo transfer.

Main Outcome Measure(s)

The oocyte quality was determined by examining mitochondrial ultrastructure using transmission electron microscopy, the adenosine triphosphate content using a luminometer, and intracellular reactive oxygen species levels by confocal microscopy. The spindle organization in mature oocytes was examined by confocal microscopy. The developmental potential of oocytes was evaluated by monitoring the in vitro embryo development and the birth rate after embryo transfer.

Result(s)

Mitochondria migrated from iGCs into the GV oocyte via transzonal filopodia. The maturation rate, quality, and developmental potential of these oocytes were substantially increased. Furthermore, the birth rate after embryo transfer has been improved.

Conclusion(s)

This approach used noninvasive procedures to collect mitochondria donor cells and optimized mitochondria transfer manipulations; thus, it may have potential in ameliorating oocyte–aging-related subfertility.