Schwann cells differentiation is affected by the redox state.

SALIS C, URTASUN N, SOTO EF, PASQUINI JM, SETTON-AVRUJ CP.

Madison, Wisconsin, Estados Unidos de Norteamérica

Congreso; 35th Annual Meeting Society for Neuroscience Madison, Estados Unidos de Norteamérica.; 2005

SCHWANN CELLS DIFFERENTIATION IS AFFECTED BY THE REDOX STATESetton-Avruj, C.P. 1, Salis, C. 1, Soto , E.F. 1, Pasquini, J.M. 1Dept.of Biol Chem, School of Pharm and Biochem, UBA, Buenos Aires, Argentina   We have previously described that 70 ng/ml Fe3+  and holoTf were able to promote SC differentiation in vitro through cAMP release and CREB phosphorylation, while apoTf that was unable.The aim of the present study was to evaluate if the intracellular redox state induced by the addition of Fe3+ is involved in this prodifferentiating effect.The content of intracellular oxidant species was measured using a 5 (or 6)-carboxy-2?L7?L-dichlorodihydrofluorescein diacetate probe (DCDCDHF), which crosses the membrane, and after oxidation, is converted into a fluorescent compound. Cells were preincubated in a serum free medium and subsequently incubated in the presence or absence of 70 ng/ml Fe3+ for 1 to 15 minutes. After rinsing, the cells were resuspended in DMEM containing 10 ƒÊM DCDCDHF and further incubated for 30 minutes at 37oC. DNA content was evaluated. Results are expressed as the ratio DCDCDHF/propidium iodide fluorescent. The effect of a potent antioxidant as N acetyl cysteine on P0 levels, a major protein of peripheral myelin and used as a differentiation marker, was measured by Western blot.Our results demonstrate that at 1, 2.5 and 5 minutes there is an increase in the intracellular content of oxidant species, that was not observed at 15 minutes. In coincidence with these results, in previous experiments the effect of 70 ng/ml Fe3+ on cAMP liberation was observed at 9 minutes. Incubation of cultured SCs in the presence of 70 ng/ml Fe3+ + N acetyl cysteine avoids the prodifferentiating effect of Fe3+ on SCs measured by the levels of P0.Further experiments will be neccessary to understand the mechanism underly in Fe3+ participation on SC differentiation and the involvement of the redox state in such an effect.