GFAP, vimentin and cyclin D1 expression in primary astroglial cell cultures treated with thioctic acid and alpha-glyceryl-phosphoryl-choline.

alpha-Glyceryl phosphoryl-choline (alpha-GPG) is a semi-synthetic derivative of phosphatidylcholines representing, among acetilcholine precursors, a relatively new cholinergic drug. Thioctic acid plays a crucial role as antioxidant and metabolic component of some enzymatic complexes involved in glucose metabolism of different cell types. In the present study, we evaluated the expression of some proliferation and differentiation markers in 21 DIV astrocyte cultures treated for 24h with 50 microM (+)thioctic acid or (+/-)thioctic acid and/or alpha-GPC (10microM). Immunocytochemical analysis showed that astroglial cells cultures treated with (+)thioctic acid or (+/-) thioctic acid and/or alpha-GPC were GFAP positive. Western blotting analysis showed that GFAP and vimentin expression increased after treatment with (+)thioctic acid compared to control ones; nevertheless, not significant modification of GFAP and vimentin expression was observed in alpha-GPC-treated astrocyte cultures. In addition, the treatment with (+)thioctic acid and alpha-GPC both togheter induced an enhancement of vimentin expression compared to control ones, but not significant modification of GFAP expression in (+)thioctic acid plus alpha-GPC treated cultures compared to control ones was found. Furthermore, by performing either the treatment with (+)thioctic acid alone or in combination with alpha-GPC, we observed an highly significant enhancement in the expression of well known proliferation marker cyclin D1, respect to the values of untreated control astrocytes. Conversely, not significant modification of cyclin D1 expression in alpha-GPC-treated astrocyte cultures was observed. The analysis of DNA status by Alkaline Comet assay showed any significant modifications to be induced by the two treatments, (+)thioctic acid or (+/-) thioctic acid resembling rather a possible genoprotective effect. Finally, these findings may better clarify the molecular mechanism evoked by the treatment with(+)thioctic acid or a-GPC, added alone or both togheter during astroglial cell proliferation and differentiation in culture, and may also suggest an eventual neuroprotective effect during glia-neuron inetractions, particularly active in neurodegenerative diseases.