Methylmercury disrupts the balance between phosphorylated and non-phosphorylated cofilin in primary cultures of mice cerebellar granule cells A proteomic study

Journal Article · Fri Jan 01 00:00:00 EST 2010 · Toxicology and Applied Pharmacology

DOI:https://doi.org/10.1016/j.taap.2009.09.022· OSTI ID:21344831

Vendrell, Iolanda ^[1]; y Salud Publica, CIBER Epidemiologia ^[2]; Carrascal, Montserrat ^[3]; Campos, Francisco ^[1]; y Salud Publica, CIBER Epidemiologia ^[2]; Abian, Joaquin ^[3]; Sunol, Cristina ^[1]; y Salud Publica, CIBER Epidemiologia ^[2]

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1. Department of Neurochemistry and Neuropharmacology, Institut d'Investigacions Biomediques de Barcelona, Consejo Superior de Investigaciones Cientificas, CSIC - IDIBAPS, Barcelona (Spain)
2. CIBERESP; Spain
3. CSIC/UAB Proteomics Laboratory, Institut d'Investigacions Biomediques de Barcelona, Consejo Superior de Investigaciones Cientificas, CSIC - IDIBAPS, Barcelona (Spain)

Methylmercury is an environmental contaminant that is particularly toxic to the developing central nervous system; cerebellar granule neurons are especially vulnerable. Here, primary cultures of cerebellar granule cells (CGCs) were continuously exposed to methylmercury for up to 16 days in vitro (div). LC50 values were 508 +- 199, 345 +- 47, and 243 +- 45 nM after exposure for 6, 11, and 16 div, respectively. Proteins from cultured mouse CGCs were separated by 2DE. Seventy-one protein spots were identified by MALDI-TOF PMF and MALDI-TOF/TOF sequencing. Prolonged exposure to a subcytotoxic concentration of methylmercury significantly increased non-phosphorylated cofilin both in cell protein extracts (1.4-fold; p < 0.01) and in mitochondrial-enriched fractions (1.7-fold; p < 0.01). The decrease in P-cofilin induced by methylmercury was concentration-dependent and occurred after different exposure times. The percentage of P-cofilin relative to total cofilin significantly decreased to 49 +- 13% vs. control cells after exposure to 300 nM methylmercury for 5 div. The balance between the phosphorylated and non-phosphorylated form of cofilin regulates actin dynamics and facilitates actin filament turnover. Filamentous actin dynamics and reorganization are responsible of neuron shape change, migration, polarity formation, regulation of synaptic structures and function, and cell apoptosis. An alteration of the complex regulation of the cofilin phosphorylation/dephosphorylation pathway could be envisaged as an underlying mechanism compatible with reported signs of methylmercury-induced neurotoxicity.

• OSTI ID: 21344831
• Journal Information: Toxicology and Applied Pharmacology, Vol. 242, Issue 1; Other Information: DOI: 10.1016/j.taap.2009.09.022; PII: S0041-008X(09)00414-1; Copyright (c) 2009 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0041-008X
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
ACTIN
APOPTOSIS
CENTRAL NERVOUS SYSTEM
IN VITRO
METHYLMERCURY
MICE
MITOCHONDRIA
NERVE CELLS
PHOSPHORYLATION
TOXICITY
ANIMAL CELLS
ANIMALS
CELL CONSTITUENTS
CHEMICAL REACTIONS
MAMMALS
NERVOUS SYSTEM
ORGANIC COMPOUNDS
ORGANIC MERCURY COMPOUNDS
PROTEINS
RODENTS
SOMATIC CELLS
VERTEBRATES