Figure 3. More apoptosis and less neurite outgrowth in dorsal root ganglion neurons of old α-galactosidase A deficient mice compared to wildtype mice.

Photomicrographs show the results of a NucView 488 Caspase 3 Enzyme Substrate Assay of cultivated dorsal root ganglion (DRG) neurons from old (≥12 months) wildtype (WT) and α-galactosidase A deficient (GLA KO) mice in the naïve state and after incubation with 500 nM staurosporine (STS) as a positive control (A–D). Empty arrows indicate caspase 3 negative neurons and filled arrows point to caspase 3 positive neurons. Bar graphs show the quantification of caspase 3 positive neurons (E). Cultured DRG neurons of old WT mice in the naïve state displayed a lower percentage of caspase 3 positive neurons than those of old GLA KO mice (p<0.001) and neurons of old WT mice incubated with 500 nM STS (p<0.05). DRG neurons of old GLA KO mice incubated with 500 nM STS showed a higher percentage of caspase 3 positive neurons compared to neurons in the naïve state (p<0.05) and WT positive control neurons (p<0.01). Further, neurite outgrowth was quantified (F). DRG neurons of old WT mice in the naïve state displayed a higher percentage of neurons with neurite outgrowth after 48 hr cultivation compared to neurons from old GLA KO mice (p<0.001). NucView 488 Caspase 3 Enzyme Substrate Assay was performed three times on cultures derived from three different mice of each genotype. GLA KO: old (≥12 months, n = 2 male, one female). WT: old (≥12 months, n = 2 male, one female). Number of neurons analyzed are integrated into the corresponding bar. Scale bar: 50 µm. The non-parametric Mann-Whitney U test for group comparisons was applied. *p<0.05;**p<0.01;***p<0.001.