Time-dependent influence of high glucose environment on the metabolism of neuronal immortalized cells

Mitochondria are organelles of bacterial origin historically identified as the cell power plant. In addition to energy, mitochondria produce reactive oxygen species and they have been found to have a key role in cell defense regulation, cell stress and damage. All the investigations regarding the nature of the molecules mediating these processes include compounds from mammalian cell metabolism. We hypothesize that the bacterial origin of mitochondria brings them to produce small fermentation products when cell is subjected to stress. In this work we studied the effect of hyperglycemia on the metabolome of hippocampal HN9.10e neurons, an in vitro model of one of the most vulnerable regions of central nervous system. Targeted metabolites were analyzed in the cell culture medium by liquid chromatography - diode array detection and headspace - gas chromatography - mass spectrometry. Twenty-two low molecular weight metabolites were identified and quantified in the growth medium of the cells, treated with 25, 50 or 75 mM glucose, sampled along 8 days to mimic a prolonged hyperglycemia. The results of statistical analysis showed the clear impairment of neuronal metabolism already after 48 h, represented by a significant reduction of the metabolic activity, together with the production of typical fermentative compounds.