Differential metabolic profiling of non-pure trisomy 21 human preimplantation embryos.

OBJECTIVE: To investigate the metabolomic signature of trisomy 21 preimplantation human embryos by a noninvasive approach using mass spectrometry- (MS-) and nuclear magnetic resonance spectroscopy- (NMR-) based metabolic profiling platforms. DESIGN: A total of 171 spent media samples were collected from day 3 embryos and comparatively analyzed by MS analysis (chromosomally normal embryos, n = 15; trisomy 21 embryos, n = 15) and a matched control media group (without embryo, n = 14) and by NMR spectroscopy (normal embryos, n = 39; trisomy 21 embryos, n = 35; monosomy 21 embryos, n = 24) and a matched control media group (without embryo, n = 29). SETTING: IVF clinic/preimplantation genetic diagnosis (PGD) unit facilities. PATIENT(S): One hundred seventy-one spent media samples obtained from human IVF embryos from patients included in our PGD program. INTERVENTION(S): Metabolomic profiling of embryo spent media using liquid chromatography/gas chromatography coupled with MS and NMR. MAIN OUTCOME MEASURE(S): Comparative identification of the metabolites present in the spent media from normal versus trisomy/monosomy 21 day 3 embryos. RESULT(S): Two metabolites, caproate and androsterone sulphate, and two unknown compounds were differentially expressed between normal and trisomy 21 day 3 embryos. Furthermore, the NMR results indicate that there could be a correlation between the differences found between trisomy 21/monosomy 21 and the normal embryos in a spectral region compatible with isoleucine. CONCLUSION(S): This study suggests that the use of differential metabolomic markers found in spent media from preimplantation embryos could be a feasible method for the detection of aneuploidies before ET.

Neuroprotection by transgenic expression of glucose-6-phosphate dehydrogenase in dopaminergic nigrostriatal neurons of mice.

Oxidative damage to dopaminergic nigrostriatal (DNS) neurons plays a central role in the pathogenesis of Parkinson's disease (PD). Glucose-6-phosphate dehydrogenase (G6PD) is a key cytoprotective enzyme that provides NADPH, the major source of the reducing equivalents of a cell. Mutations of this enzyme are the most common enzymopathies worldwide. We have studied in vivo the role of G6PD overexpressed specifically in the DNS pathway and show that the increase of G6PD activity in the soma and axon terminals of DNS neurons, separately from other neurons or glial cells, protects them from parkinsonism. Analysis of DNS neurons by histological, neurochemical, and functional methods showed that even a moderate increase of G6PD activity rendered transgenic mice more resistant than control littermates to the toxic effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The neuroprotective action of G6PD was also observed in aged animals despite that they had a greater susceptibility to MPTP. Therefore, overexpression of G6PD in dopaminergic neurons or pharmacological activation of the native enzyme should be considered as potential therapeutic strategies to PD.