EFFECT OF THIOCTIC ACID AND ALPHA-GLYCERYL PHOSPHORYL-CHOLINE ON ASTROGLIAL CELL PROLIFERATION AND DIFFERENTIATION IN PRIMARY CULTURE

Thioctic acid plays a crucial role as antioxidant and metabolic component of some enzymatic complexes involved in glucose metabolism of different cell types. -glyceryl phosphoryl-choline (-GPG) is a semi-synthetic derivative of phosphatidylcholines representing, among acetilcholine precursors, a relatively new cholinergic drug. In the present study, we evaluated the expression of some proliferation and differentiation markers in 15 DIV astrocyte cultures elicited by 50 M (+)thioctic acid or (+/-) thioctic acid and/or -GPC (10M) treatment. Immunocytochemical analysis showed GFAP positivity of astroglial cells cultures treated with (+)thioctic acid or (+/-) thioctic acid and/or -GPC. 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 -GPC-treated astrocyte cultures. In addition, the treatment with (+)thioctic acid and -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. In addition, 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. Other experiments are in progress in our laboratory in order to evaluate the levels of some well known proliferation, differentiation and apoptotic biomarkers, such as Ornityne decarboxilase, MAP-Kinase, PARP, in (+)thioctic acid and/or alpha-GPC-treated astrocyte cultures. This to assess the neuroprotective role played by these metabolic and antioxidant molecules in astroglial compartment, during interactive cross-talk between glial and neuronal cells, after brain lesions or damages.