Protective effects of neurotrophin-4/5 and transforming growth factor-alpha on striatal neuronal phenotypic degeneration after excitotoxic lesioning with quinolinic acid.
Lesioning of the mammalian striatum with the excitotoxin quinolinic acid results in a pattern of neuropathology that resembles that of post mortem Huntington's disease brain. Certain neurotrophic factors can rescue degenerating cells in a variety of lesion types, including those produced by neurotoxins. Several neurotrophic factors promote the survival of striatal neurons and/or are localized within the striatum. Of these factors, neurotrophin-4/5 and transforming growth factor-alpha were chosen for administration to rats lesioned with quinolinic acid. Adult rats received a single unilateral intrastriatal injection of quinolinic acid (120 nmol) and either trophic factors or the control protein cytochrome c for seven days thereafter. The pattern of phenotypic degeneration was assessed by immunocytochemical labeling of various striatal neuronal populations at five rostrocaudal levels. Quinolinic acid produced a preferential loss in the number of cells immunoreactive for glutamate decarboxylase, with a relative sparing of the number of choline acetyltransferase-immunoreactive cells and, to a lesser degree, calretinin-immunoreactive cells. None of these phenotypic populations was protected by either neurotrophin-4/5 or transforming growth factor-alpha. In contrast, when glutamate decarboxylase cells were alternatively identified by calbindin immunolabeling, both factors were found to have partially reversed the loss in the number of calbindin-positive cells induced by excitolesioning. In addition, the loss in the number of parvalbumin-immunopositive cells due to quinolinic acid was partially reversed by neurotrophin-4/5, while the loss in the number of NADPH-diaphorase-stained cells was partially reversed by transforming growth factor-alpha. These findings reveal a new population of striatal cells, calretinin neurons, that are relatively resistant to quinolinic acid toxicity and that neurotrophin-4/5 and transforming growth factor-alpha partially protect against the phenotypic degeneration of striatal cell populations in an in vivo animal model of Huntington's disease.
Alexi
T
T
University of Southern California, Department of Biology, Los Angeles 90089, U.S.A.
Venero
J L
JL
Hefti
F
F
D000818:Animals; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002452:Cell Count; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D005260:Female; D005968:Glutamate Decarboxylase / Q000378:metabolism; D007150:Immunohistochemistry; D009252:NADPH Dehydrogenase / Q000378:metabolism; D017072:Neostriatum / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology; D009410:Nerve Degeneration / Q000187:drug effects*; D009414:Nerve Growth Factors / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D018696:Neuroprotective Agents / Q000494:pharmacology*; D010641:Phenotype; D017378:Quinolinic Acid / Q000633:toxicity; D051381:Rats; D017208:Rats, Wistar; D016211:Transforming Growth Factor alpha / Q000494:pharmacology*
D002135:Calcium-Binding Proteins; D009414:Nerve Growth Factors; D018696:Neuroprotective Agents; D016211:Transforming Growth Factor alpha; C071951:neurotrophin 5; D009252:NADPH Dehydrogenase; D002795:Choline O-Acetyltransferase; D005968:Glutamate Decarboxylase; D017378:Quinolinic Acid; C073922:neurotrophin 4