GM1 and nerve growth factor modulate mitochondrial membrane potential and neurofilament light mRNA expression in cultured dorsal root ganglion and spinal cord neurons during excitotoxic glutamate exposure.
Monosialoganglioside GM1 is a known neurotrophic factor. Nerve growth factor (NGF), a member of the neurotrophin family, is important for the survival, differentiation and maturation of neurons. The aim of this study was to test whether administration of GM1 and NGF can ameliorate glutamate (Glu) neurotoxicity in primary cultured embryonic rat dorsal root ganglia (DRG) and spinal cord neurons, and to investigate the mechanism underlying any effect. DRG and spinal cord neurons were exposed to the following treatments: Glu (2 mmol/L); Glu (2 mmol/L) plus GM1 (10mg/mL); Glu (2 mmol/l) plus NGF (10 ng/mL); Glu (2 mmol/L) plus GM1 (5mg/mL) and NGF (5 ng/mL). Cell viability was assessed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, ultrastructural alterations were examined using inverse phase contrast microscopy and electron microscopy, mitochondrial membrane potential was measured using rhodamine 123 labeling and flow cytometry, and neurofilament light (NF-L) mRNA expression was detected by reverse transcription-polymerase chain reaction. It was found that GM1 and NGF can increase the viability of neurons incubated with Glu, which, after GM1 and NGF treatment, were almost morphologically normal. The mitochondrial membrane potential of neurons was lowest for neurons treated with Glu alone, and that for neurons treated with Glu plus GM1 and NGF was higher than that for treatment with GM1 or NGF alone. The mRNA of NF-L was expressed at the highest level in neurons treated with Glu plus GM1 and NGF. Our findings indicate that NGF and GM1 act synergistically to protect DRG and spinal cord neurons from Glu cytotoxicity. NGF and GM1 may function by maintaining normal mitochondrial membrane potential or by promoting NF-L mRNA expression.
Huang
Fei
F
Department of Human Anatomy, Binzhou Medical College, 346 Guanhai Road, Laishan, Yantai 264003, China.
Dong
Xifeng
X
Zhang
Luping
L
Zhang
Xuejun
X
Zhao
Dongmei
D
Bai
Xianyong
X
Li
Zhenzhong
Z
D000818:Animals; D002469:Cell Separation; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004357:Drug Synergism; D005434:Flow Cytometry; D005677:G(M1) Ganglioside / Q000494:pharmacology*; D005727:Ganglia, Spinal / Q000187:drug effects / Q000648:ultrastructure; D018698:Glutamic Acid / Q000633:toxicity; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects*; D046529:Microscopy, Electron, Transmission; D020932:Nerve Growth Factor / Q000494:pharmacology*; D016900:Neurofilament Proteins / Q000096:biosynthesis / Q000187:drug effects*; D009474:Neurons / Q000187:drug effects* / Q000648:ultrastructure; D018696:Neuroprotective Agents / Q000494:pharmacology*; D012333:RNA, Messenger; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013116:Spinal Cord / Q000187:drug effects
D016900:Neurofilament Proteins; D018696:Neuroprotective Agents; D012333:RNA, Messenger; C044882:neurofilament protein L; D005677:G(M1) Ganglioside; D018698:Glutamic Acid; D020932:Nerve Growth Factor