Sz. Lin et al., Minocycline blocks nitric oxide-induced neurotoxicity by inhibition p38 MAP kinase in rat cerebellar granule neurons, NEUROSCI L, 315(1-2), 2001, pp. 61-64
Minocycline, a semisynthetic second-generation tetracycline, was reported t
o have neuroprotective effects in models of global and focal cerebral ische
mia, the R6/2 mouse model of Huntington disease, as well as glutamate-induc
ed neurotoxicity in mixed neuronal/glial cultures. It was suggested that ne
uroprotective effects of minocycline resulted from inhibition of microglial
/astroglial activation 'Proc. Natl. Acad. Sci. USA 95 1998 15769'. To deter
mine whether or not minocycline is able to directly protect neurons against
injury insults and to delineate its neuroprotective mechanism(s), we treat
ed cultured rat cerebellar granule neurons (CGN) with nitric oxide (NO) in
the presence or absence of minocycline. We found that minocycline protected
neurons against NO-induced neuronal death in a concentration-dependent fas
hion. Consistent to other reports, NO was able to induce p38 MAP kinase pho
sphorylation at 3-6 h and such an induction could be significantly inhibite
d by minocycline. Furthermore, SB 203580, a p38 MAP kinase inhibitor, almos
t completely attenuated NO-induced neuronal death of CGN as well. These res
ults suggest that minocycline is able to block NO-induced neurotoxicity in
CGN by inhibiting NO-induced phosphorylation of p38 MAP kinase. Our finding
may explain the neuroprotective mechanism of minocycline in those neurodeg
enerative models. (C) 2001 Elsevier Science Ireland Ltd. All rights reserve
d.