Different patterns of induction of fibroblast growth factor-2 and brain-derived neurotrophic factor messenger RNAs during kindling epileptogenesis, and development of a herpes simplex vector for fibroblast growth factor-2 gene transfer in vivo.
OBJECTIVE
To investigate the gene expression patterns of brain-derived neurotrophic factor (BDNF) and fibroblast growth factor-2 (FGF-2) in the kindling model, and to construct a replication-defective herpes simplex virus vector to induce expression of FGF-2 in vivo.


METHODS
RNase protection assay and herpes simplex virus vector (TH FGF-2) deleted in the immediate-early genes ICP4, ICP22, and ICP27, with FGF-2 inserted in tk under the control of the human cytomegalovirus immediate-early promoter.


RESULTS
A single kindling stimulation did not modify BDNF gene expression, whereas it increased FGF-2 messenger RNA (mRNA) levels in the hippocampus, the cortex, and the hypothalamus. BDNF and FGF-2 gene expression were not altered in kindled animals left unstimulated for 1 week. In contrast, kindled seizures produced a great increase in hippocampal and cortical BDNF mRNA levels, but FGF-2 mRNA was increased only in the ipsilateral cortex. Infection of Vero cells with TH FGF-2 resulted in a long-lasting increase in FGF-2 levels. Protein extracts of infected cells induced neuronal differentiation of PC12 cells, indicating that the newly synthesized FGF-2 was biologically active. Robust transient transgene expression was observed in the rat hippocampus after inoculation with TH FGF-2 in the absence of significant toxicity.


CONCLUSIONS
BDNF and FGF-2 are recruited at different stages of kindling and, accordingly, may play different roles in the adaptive changes taking place during epileptogenesis. TH FGF-2 is suitable for studies of FGF-2 involvement in kindling epileptogenesis.
Bregola
G
G
Department of Experimental and Clinical Medicine, Biotechnology Center, University of Ferrara, Italy.
Frigati
L
L
Zucchini
S
S
Simonato
M
M
D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics* / Q000378:metabolism*; D003673:Defective Viruses / Q000235:genetics; D004827:Epilepsy / Q000139:chemically induced / Q000235:genetics* / Q000378:metabolism*; D016222:Fibroblast Growth Factor 2 / Q000235:genetics* / Q000378:metabolism*; D015870:Gene Expression; D018014:Gene Transfer Techniques; D005822:Genetic Vectors / Q000235:genetics; D006624:Hippocampus / Q000737:chemistry / Q000378:metabolism; D017403:In Situ Hybridization; D007696:Kindling, Neurologic / Q000378:metabolism*; D008297:Male; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D018139:Simplexvirus / Q000235:genetics*; D019076:Transgenes / Q000235:genetics
D019208:Brain-Derived Neurotrophic Factor; D012333:RNA, Messenger; D016222:Fibroblast Growth Factor 2