Rescue of Mesencephalic Dopamine Neurons by Anticancer Drug Cytosine Arabinoside

Abstract

Nanomolar concentrations of cytosine arabinoside (ara-C), a structural analogue of 2 '-deoxycytidine (2'dC) used in the chemotherapy of cancer, proved to be highly effective in preventing the death of postmitotic dopaminergic neurons that occurs spontaneously by apoptosis in mesencephalic cultures. The rescued cells were totally functional and highly differentiated. The trophic/neuroprotective effects of ara-C were (1) specific for dopaminergic neurons; (2) long-lived, remaining detectable several days after withdrawal of the nucleoside analogue from the culture medium; (3) still observed when the treatment was delayed after plating; (4) abolished by an excess of 2'dC or dCTP, or by exposure to the neurotoxin 1-methyl-4-phenylpyridinium; and (5) mimicked by ara-CTP, 5-fluoro-2 '-deoxyuridine, and aphidicolin. Autoradiographic studies revealed that ara-C was incorporated exclusively into astrocyte nuclei, suggesting that the dopaminotrophic activity was indirect and resulted from the antiproliferative action of the modified nucleoside on glial cells at concentrations that were not neurotoxic. No evidence was found for putative deleterious or trophic molecules secreted by proliferating or ara-C-treated astrocytes, respectively, suggesting that neuroglial contact may play a role. Our results suggest a possible mechanism underlying neurodegeneration in Parkinson's disease, where selective loss of dopaminergic neurons in the mesencephalon is accompanied by astrogliosis.

Adenosine Prevents the Death of Mesencephalic Dopaminergic Neurons by a Mechanism that Involves Astrocytes

“…1C) that occurs spontaneously and progressively in this culture model (Michel and Agid, 1996;Michel et al, 1997~).…”

“…86/609 and with the local ethical committee guidelines for animal research. Cultures of postmitotic dopaminergic neurons were prepared from the ventral mesencephalon of embryonic day 15.5 Wistar rat embryos (Michel and Agid, 1996;Michel et al, 1997~). After dissection, mesencephalic tissue was mechanically dissociated and plated in polyethylenimine (1 mg/ml; Sigma)-precoated culture plates (24 wells) or Labtek glass chamber slides .…”

Mitochondrial ATP-sensitive potassium channels enhance angiotensin-induced oxidative damage and dopaminergic neuron degeneration. Relevance for aging-associated susceptibility to Parkinson’s disease

“…The cultures were then treated with the dopaminergic neurotoxins 6-OHDA (6-hydroxydopamine) or MPP + (1-methyl-4-phenylpyridinium), or 6-OHDA or MPP + and 5-HD (5-hydroxydecanoic acid, see below). This method can enrich neurons to >85% purity (Michel et al 1997;Gao et al 2003).…”

Creatine Supplementation Improves Dopaminergic Cell Survival and Protects against MPP+ Toxicity in an Organotypic Tissue Culture System

“…Hence, the aplogical activity. Based on this notion, it is suggested that the usage of cultures with a significantly smaller extent reported to contribute to the loss of embryonic dopaminergic nigral cells in culture (21,62). Programmed cell of cell-cell contact than the organotypic FFRT approach might result in a more pronounced effect of creatine death occurring as a natural phenomenon in a biphasic pattern with a first peak of apoptotic dopaminergic neutreatment on dopaminergic neurons survival.…”