Dosage-dependent Induction of Behavioral Decline in Caenorhabditis elegans by Long-term Treatment of Static Magnetic Fields

• Published in: JOURNAL OF RADIATION RESEARCH Vol. 53; no. 1; pp. 24 - 32
• Main Authors: Lee, Chia-Hui, Chen, Huang-Meng, Yeh, Li-Ke, Hong, Meng-Yen, Huang, Guewha Steven
• Format: Journal Article
• Language: English
• Published: England THE JAPAN RADIATION RESEARCH SOCIETY 2012; Oxford University Press
• Subjects: Aging - genetics; Animals; Apoptosis; Apoptosis - drug effects; Apoptosis - genetics; Biological products; Caenorhabditis elegans; Caenorhabditis elegans - physiology; Caenorhabditis elegans Proteins - biosynthesis; Caenorhabditis elegans Proteins - genetics; Cancer genetics; Caspase 3 - biosynthesis; Caspase 3 - genetics; Cytochalasin D - pharmacology; Gene expression; Gene Expression Regulation; Genetic aspects; Health aspects; Locomotion; Magnetic fields; Magnetic Fields - adverse effects; Mutagenicity Tests; Nematoda; Oxidative Stress - genetics; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; Time Factors
• ISSN: 0449-3060; 1349-9157
• DOI: 10.1269/jrr.11057

The aim of this work was to explore the molecular mechanisms associated with possible health hazards induced by static magnetic fields (SMFs). Nematodes were grown under SMFs at field strengths from 0 to 200 mT, and the speed of body movement was measured. The effects of exposure to static magnetic fields were observed to be significant in the higher field strength and longer treatment. To explore the possible molecular mechanisms responsible for these effects, semi-quantitative real-time RT-PCR was performed using primers specific to 120 randomly selected genes. Twenty-six differentially expressed genes among apoptosis-, oxidative stress-, and cancer-related genes were identified, indicating that a global molecular response to SMF treatment occurred. The induction of apoptosis was verified by the increase of fluorescence in a terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, by the caspase-3 activity assay, and by immunostaining using an antibody against the ced-3 gene product. Mutations in genes involved in major apoptotic pathways, that is, ced-3, ced-4, and ced-9, abolished this SMF-induced behavioral decline;this is consistent with the hypothesis that the apoptosis pathways are involved in the SMF-induced mobility decline. Here we show that long-term and low-dosage exposure to SMF is capable of inducing an apoptosis-mediated behavioral decline in nematodes.