Neuroprotection by NGF in the PC12 in vitro OGD model: involvement of mitogen-activated protein kinases and gene expression.
Neurodegenerative disorders and chronic disability due to stroke in the brain or spinal cord afflict a large sector of the population. To investigate the mechanism involved in ischemic stroke and to develop neuroprotective drugs/therapies, in vivo and in vitro, pharmacological models are needed. To investigate the cellular and molecular neuroprotective mechanisms of nerve growth factor (NGF), a member of the nervous system neurotrophin family of growth factors, under ischemia, we used an oxygen-glucose-deprivation (OGD) device and pheochromocytoma PC12 cells exposed to a paradigm of ischemic insult. Pretreatment of the cultures with 50 ng/mL of NGF, 18 h prior to OGD insult, conferred 30% of neuroprotection. Time-course experiments showed marked activation of the ERK, JNK, and p-38 MAPK isoforms during the OGD phase, but not during OGD reperfusion. Pretreatment of the cultures with 50 ng/mL of NGF, 18 h prior to OGD insult, resulted in 50% attenuation of OGD-induced activation of JNK 1, and 20% and 50% attenuation of OGD-induced activation of p-38 alpha and beta, respectively. The effect of NGF on gene expression in the PC12 ischemic model using Affymatrix Rat DNA-Microarray technology indicates that only 6% of the genes are differentially regulated (induced/suppressed) by OGD insult and/or NGF. These findings support the notion that pretreatment with NGF confers neuroprotection from OGD insult, a phenomenon coincidentally related to differential inhibition of MAPK stress kinase isoforms and differential gene expression. This ischemic model may be useful to investigate molecular mechanisms of OGD-induced neurotoxicity and NGF-induced neuroprotection, and to generate novel therapeutic concepts for stroke treatment.
Tabakman
Rinat
R
Department of Pharmacology and Experimental Therapeutics, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel.
Jiang
Hao
H
Shahar
Iris
I
Arien-Zakay
Hadar
H
Levine
Robert A
RA
Lazarovici
Philip
P
D000818:Animals; D002545:Brain Ischemia / Q000188:drug therapy / Q000517:prevention & control; D015870:Gene Expression / Q000187:drug effects*; D005947:Glucose / Q000172:deficiency*; D002534:Hypoxia, Brain / Q000473:pathology*; D020928:Mitogen-Activated Protein Kinases / Q000502:physiology*; D009414:Nerve Growth Factors / Q000494:pharmacology*; D018696:Neuroprotective Agents; D016716:PC12 Cells; D051381:Rats; D020521:Stroke / Q000188:drug therapy / Q000517:prevention & control
D009414:Nerve Growth Factors; D018696:Neuroprotective Agents; D020928:Mitogen-Activated Protein Kinases; D005947:Glucose