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Evaluation of the protective effect of oestradiol against toxicity induced by 6‐hydroxydopamine and 1‐methyl‐4‐phenylpyridinium ion (MPP + ) towards dopaminergic mesencephalic neurones in primary culture
Author(s) -
Callier Sophie,
Le Saux Maryvonne,
Lhiaubet AnneMarie,
Paolo Thérèse Di,
Rostène William,
Pelaprat Didier
Publication year - 2002
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1046/j.0022-3042.2001.00693.x
Subject(s) - dopaminergic , hydroxydopamine , dopamine , toxicity , tyrosine hydroxylase , medicine , neuroprotection , endocrinology , neurotoxicity , biology , chemistry , pharmacology
Recent findings suggest that gonadal steroid hormones are neuroprotective and may provide clinical benefits in delaying the development of Parkinson's disease. In this report we investigated the ability of oestradiol to protect mesencephalic dopaminergic neurones cultured in serum‐free or serum‐supplemented medium from toxicity induced by 6‐hydroxydopamine or 1‐methyl‐4‐phenylpyridinium ion (MPP + ). The efficiency of both toxins and oestradiol was evaluated by tyrosine hydroxylase (TH) immunocytochemistry, [ 3 H]dopamine ([ 3 H]DA) uptake, length of dopaminergic processes and␣lactate dehydrogenase (LDH) release measurement. In␣cultures grown in serum‐supplemented medium, a 2‐h pre‐treatment with high concentrations (10–100 µ m ) of 17β‐oestradiol or 17α‐oestradiol, the stereoisomer with weak oestrogenic activity, protected both dopaminergic and non‐dopaminergic neurones from toxicity induced by 6‐hydroxydopamine (6‐OHDA; 40 or 100 µ m ) and by the high MPP + concentrations (50 µ m ) necessary to obtain significant neuronal death under those culture conditions. At these concentrations, MPP + was no longer selective for dopaminergic neurones but affected all cells present in the culture. In contrast, the hormonal treatments did not protect against selective degeneration of dopaminergic neurones induced by lower MPP + concentrations (below 10 µ m ), related to inhibition of complex I of respiratory chain. In cultures grown in serum‐free medium, oestradiol concentrations higher than 1 µ m induced neuronal degeneration and no protection against 6‐OHDA or MPP + toxicity was observed at lower concentrations of the steroid. The neuroprotective effects of 17α‐ or 17β‐oestradiol evidenced in this model might be due to the antioxidant properties of these compounds. However, other non‐genomic effects of the steroids cannot be excluded.