Effects of gangliosides on ethanol-induced neurodegeneration in the developing mouse brain.
BACKGROUND
Ethanol exposure induces apoptotic neurodegeneration in the developing rodent brain during synaptogenesis. This process has been studied as a model for fetal alcohol syndrome. Previously, we have shown that gangliosides and LIGA20 (a semisynthetic derivative of GM1 ganglioside) attenuate ethanol-induced apoptosis in cultured neurons. In the present study, the effects of GM1 and LIGA20 on ethanol-induced apoptotic neurodegeneration were examined using an in vivo neonatal mouse model.


METHODS
Seven-day-old C57BL/6By (B6By) mice were pretreated twice with intraperitoneal administration of GM1 (30 mg/kg), LIGA20 (2.5 mg/kg), or saline, followed by subcutaneous injection of either saline or ethanol (2.5 g/kg) twice with a 2 hours interval. Then the brains were: (1) perfusion-fixed 24 hours after the first ethanol injection, and the extent of neurodegeneration was assessed by cupric silver staining of the brain sections, or (2) perfusion-fixed 8 hours after the first ethanol injection, and the sections were immunostained with anti-cleaved (activated) caspase-3 antibody to evaluate caspase-3 activation.


RESULTS
The comparison of cupric silver stained coronal sections indicates that ethanol-induced widespread neurodegeneration in the forebrains of B6By mice was reduced overall by GM1 and LIGA20 pretreatments. The extent of neurodegeneration detected by silver impregnation and activated caspase-3 immunostaining was quantified in the cingulate and retrosplenial cortices, which were the regions most severely affected by ethanol. The results indicate that GM1 and LIGA20 pretreatments induced statistically significant reductions-approximately 50% of the ethanol-treated samples-in silver impregnation and activated caspase-3 immunostaining. No significant differences were observed between saline controls and samples treated with GM1 or LIGA20 alone.


CONCLUSIONS
These results indicate that GM1 and LIGA20, which have been shown to be neuroprotective against insults caused by various agents, partially attenuate ethanol-induced apoptotic neurodegeneration in the developing mouse brain.
Saito
Mariko
M
Laboratory of Neurobehavior Genetics, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, New York, USA. marsaito@nki.rfmh.org
Mao
Rui-Fen
RF
Wang
Ray
R
Vadasz
Csaba
C
Saito
Mitsuo
M
D000818:Animals; D000831:Animals, Newborn; D017209:Apoptosis / Q000187:drug effects; D001921:Brain / Q000254:growth & development* / Q000473:pathology*; D053148:Caspase 3 / Q000378:metabolism; D002492:Central Nervous System Depressants / Q000097:blood / Q000633:toxicity*; D004789:Enzyme Activation; D000431:Ethanol / Q000097:blood / Q000633:toxicity*; D005455:Fluorescent Antibody Technique; D005677:G(M1) Ganglioside / Q000031:analogs & derivatives / Q000627:therapeutic use; D005732:Gangliosides / Q000627:therapeutic use*; D051379:Mice; D008810:Mice, Inbred C57BL; D009410:Nerve Degeneration / Q000139:chemically induced* / Q000473:pathology / Q000523:psychology*; D010477:Perfusion; D016622:Silver Staining; D013110:Sphingosine / Q000031:analogs & derivatives / Q000627:therapeutic use; D016707:Tissue Fixation
D002492:Central Nervous System Depressants; D005732:Gangliosides; C086919:LIGA 20; D005677:G(M1) Ganglioside; D000431:Ethanol; D053148:Caspase 3; D013110:Sphingosine