Expression, activity, and role of serine palmitoyltransferase in the rat hippocampus after kainate injury.
An increase in ceramide species has been shown recently by lipidomic analysis of the rat hippocampus after kainate-induced excitotoxic injury (Guan et al. [2006] FASEB J 20:1152-1161). In this study, we showed increased expression of serine palmitoyltransferase (SPT), the first enzyme in the ceramide biosynthetic pathway, in reactive astrocytes of the hippocampus after kainate injections. The increase in enzyme expression was paralleled by increased SPT enzyme activity in the hippocampus at 2 weeks post-kainate injection. In vitro studies showed that treatment of hippocampal slice cultures with SPT inhibitor ISP-1 (myriocin) or L-cycloserine modulated increases in 16:0, 18:0, and 20:0 ceramide species, and partially reduced kainate-induced cell death. The above findings indicate a role of SPT in ceramide increase after kainate injury, although additional effects of sphingomyelinase cannot be ruled out. They also suggest that SPT activity might contribute to neuronal injury after kainate excitotoxicity.
He
Xin
X
Department of Anatomy, National University of Singapore, Singapore.
Guan
Xue-Li
XL
Ong
Wei-Yi
WY
Farooqui
Akhlaq A
AA
Wenk
Markus R
MR
D000818:Animals; D000963:Antimetabolites / Q000494:pharmacology; D001253:Astrocytes / Q000187:drug effects / Q000201:enzymology; D015153:Blotting, Western; D002518:Ceramides / Q000378:metabolism; D003523:Cycloserine / Q000494:pharmacology; D018690:Excitatory Amino Acid Agonists / Q000633:toxicity*; D005229:Fatty Acids, Monounsaturated / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects / Q000201:enzymology*; D007150:Immunohistochemistry; D007608:Kainic Acid / Q000633:toxicity*; D009410:Nerve Degeneration / Q000201:enzymology; D009924:Organ Culture Techniques; D051381:Rats; D017208:Rats, Wistar; D051102:Serine C-Palmitoyltransferase / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization
D000963:Antimetabolites; D002518:Ceramides; D018690:Excitatory Amino Acid Agonists; D005229:Fatty Acids, Monounsaturated; D003523:Cycloserine; D051102:Serine C-Palmitoyltransferase; D007608:Kainic Acid; C001996:thermozymocidin