Figure 4.

Overexpression of arginase prevented motor neuron death induced by trophic factor deprivation. Motor neurons were electroporated with the pEGFP.C1 vector alone (filled bars) or in combination with the pEIF/Myc-His C vector containing the gene for the arginase 1 (open bars). Motor neurons were incubated in the presence of trophic factors overnight. Motor neuron survival was determined 3 d after trophic factor deprivation by counting all fluorescent cells. The protection provided by overexpression of arginase 1 was reversed by incubation with 1 μm NOHA or 20 μm DETANONOate [(Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl) amino]diazen-1-ium-1,2-diolate]. Overexpression of arginase 1 did not affect the survival of motor neurons incubated with 1 ng/ml BDNF at the moment of changing the medium. Values are the mean ± SD from at least three independent experiments performed in quadruplicate. *p < 0.01 versus trophic factor deprivation (TFD); **p < 0.01 versus arginase 1.