Ascorbic acid (AA), the reduced form of
vitamin C, acts as a neuroprotector by eliminating
free radicals in the brain.
Sodium/
vitamin C co-transporter isoform 2 (SVCT2) mediates uptake of AA by neurons. It has been reported that SVCT2
mRNA is induced in astrocytes under ischemic damage, suggesting that its expression is enhanced in pathological conditions. However, it remains to be established if SVCT expression is altered in the presence of reactive
astrogliosis generated by different brain pathologies. In the present work, we demonstrate that SVCT2 expression is increased in astrocytes present at sites of
neuroinflammation induced by intracerebroventricular injection of a GFP-adenovirus or the microbial
enzyme,
neuraminidase. A similar result was observed at 5 and 10 days after damage in a model of traumatic injury and in the hippocampus and cerebral cortex in the in vivo kindling model of
epilepsy. Furthermore, we defined that cortical astrocytes maintained in culture for long periods acquire markers of reactive
gliosis and express SVCT2, in a similar way as previously observed in situ. Finally, by means of second harmonic generation and 2-photon fluorescence imaging, we analyzed brain necropsied material from patients with
Alzheimer's disease (AD), which presented with an accumulation of
amyloid plaques. Strikingly, although AD is characterized by focalized
astrogliosis surrounding
amyloid plaques, SVCT2 expression at the astroglial level was not detected. We conclude that SVCT2 is heterogeneously induced in reactive
astrogliosis generated in different pathologies affecting the central nervous system (CNS).