Assessing Vesicular Monoamine Transport and Toxicity Using Fluorescent False Neurotransmitters
| Autor: | Carlie A. Black, Gary W. Miller, Kenny Igarza, Meghan L Bucher, Lauren Jonas, Joshua M. Bradner |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Tetrabenazine
010501 environmental sciences Pharmacology Toxicology Vesicular monoamine transporter 2 01 natural sciences Article 03 medical and health sciences Dopamine Monoaminergic medicine Humans Cells Cultured 030304 developmental biology 0105 earth and related environmental sciences 0303 health sciences Neurotransmitter Agents Microscopy Confocal biology Molecular Structure Chemistry General Medicine Reserpine Methamphetamine Monoamine neurotransmitter HEK293 Cells Microscopy Fluorescence Vesicular Monoamine Transport Proteins biology.protein Monoamine transport medicine.drug |
| Zdroj: | Chem Res Toxicol |
| ISSN: | 1520-5010 |
| Popis: | Impairments in the vesicular packaging of dopamine result in an accumulation of dopamine in the cytosol. Cytosolic dopamine is vulnerable to two metabolic processes - enzymatic catabolism and enzymatic- or auto-oxidation - that form toxic metabolites and generate reactive oxygen species. Alterations in the expression or activity of the vesicular monoamine transporter 2 (VMAT2), which transports monoamines such as dopamine from the cytosol into the synaptic vesicle, result in dysregulated dopamine packaging. Here, we developed a series of assays using the fluorescent false neurotransmitter 206 (FFN206) to visualize VMAT2-mediated vesicular packaging at baseline and following pharmacological and toxicological manipulations. As proof of principle, we observed a significant reduction in vesicular FFN206 packaging after treatment with the VMAT2 inhibitors reserpine (IC(50): 73.09 nM), tetrabenazine (IC(50): 30.41 nM), methamphetamine (IC(50): 2.399 μM), and methylphenidate (IC(50): 94.33 μM). We then applied the assay to investigate the consequences on vesicular packaging by environmental toxicants including the pesticides paraquat, rotenone, and chlorpyrifos, as well as the halogenated compounds unichlor, perfluorooctanesulfonic acid, Paroil, Aroclor 1260, and hexabromocyclododecane. Several of the environmental toxicants showed minor impairment of vesicular FFN206 loading, suggesting that the toxicants are weak VMAT2 inhibitors at the concentrations tested. The assay presented here can be applied to investigate the effect of additional pharmacological compounds and environmental toxicants on vesicular function, which will provide insight into how exposures to such factors are involved in the pathogenesis of monoaminergic diseases such as Parkinson’s disease, and the assay can be used to identify pharmacological agents that influence VMAT2 activity. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|