Activation of GSK-3β and caspase-3 occurs in Nigral dopamine neurons during the development of apoptosis activated by a striatal injection of 6-hydroxydopamine.
The 6-Hydroxydopamine (6-OHDA) rat model of Parkinson's disease is essential for a better understanding of the pathological processes underlying the human disease and for the evaluation of promising therapeutic interventions. This work evaluated whether a single striatal injection of 6-OHDA causes progressive apoptosis of dopamine (DA) neurons and activation of glycogen synthase kinase 3β (GSK-3β) and caspase-3 in the substantia nigra compacta (SNc). The loss of DA neurons was shown by three neuron markers; tyrosine hydroxylase (TH), NeuN, and β-III tubulin. Apoptosis activation was determined using Apostain and immunostaining against cleaved caspase-3 and GSK-3β pY216. We also explored the possibility that cleaved caspase-3 is produced by microglia and astrocytes. Our results showed that the 6-OHDA caused loss of nigral TH(+) cells, progressing mainly in rostrocaudal and lateromedial directions. In the neostriatum, a severe loss of TH(+) terminals occurred from day 3 after lesion. The disappearance of TH(+) cells was associated with a decrease in NeuN and β-III tubulin immunoreactivity and an increase in Apostain, cleaved caspase-3, and GSK-3β pY216 in the SNc. Apostain immunoreactivity was observed from days 3 to 21 postlesion. Increased levels of caspase-3 immunoreactivity in TH(+) cells were detected from days 1 to 15, and the levels then decreased to day 30 postlesion. The cleaved caspase-3 also collocated with microglia and astrocytes indicating its participation in glial activation. Our results suggest that caspase-3 and GSK-3β pY216 activation might participate in the DA cell death and that the active caspase-3 might also participate in the neuroinflammation caused by the striatal 6-OHDA injection.
Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, México, DF, México.
Daniel
D
Hernandez-Baltazar
Maria E
ME
Mendoza-Garrido
Daniel
D
Martinez-Fong
D000818:Animals; D034961:Antigens, Nuclear / Q000378:metabolism; D017209:Apoptosis; D053148:Caspase 3 / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism; D059290:Dopaminergic Neurons / Q000201:enzymology*; D004789:Enzyme Activation; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D008297:Male; D009419:Nerve Tissue Proteins / Q000378:metabolism; D016627:Oxidopamine; D010302:Parkinson Disease, Secondary / Q000139:chemically induced / Q000201:enzymology*; D051381:Rats; D017208:Rats, Wistar; D013378:Substantia Nigra / Q000201:enzymology* / Q000473:pathology; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
D034961:Antigens, Nuclear; D009419:Nerve Tissue Proteins; C546339:Rbfox3 protein, rat; D016627:Oxidopamine; D014446:Tyrosine 3-Monooxygenase; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; C000605508:Gsk3b protein, rat; D038362:Glycogen Synthase Kinase 3; C505410:Casp3 protein, rat; D053148:Caspase 3