title: Effects of environmental noise exposure on DNA methylation in the brain and metabolic health.
abstract: Environmental noise exposure is associated with adverse effects on human health including hearing loss, heart disease, and changes in stress-related hormone levels. Alteration in DNA methylation in response to environmental exposures is a well-known phenomenon and it is implicated in many human diseases. Understanding how environmental noise exposures affect DNA methylation patterns may help to elucidate the link between noise and adverse effects on health. In this pilot study we examined the effects of environmental noise exposure on DNA methylation of genes related to brain function and investigated whether these changes are related with metabolic health. We exposed four groups of male Wistar rats to moderate intensity noise (70-75dB with 20-4000Hz) at night for three days as short-term exposure, and for three weeks as long-term exposure. Noise exposure was limited to 45dB during the daytime. Control groups were exposed to only 45dB, day and night. We measured DNA methylation in the Bdnf, Comt, Crhr1, Mc2r, and Snca genes in tissue from four brain regions of the rats (hippocampus, frontal lobe, medulla oblongata, and inferior colliculus). Further, we measured blood pressure and body weight after long-term noise exposure. We found that environmental noise exposure is associated with gene-specific DNA methylation changes in specific regions of the brain. Changes in DNA methylation are significantly associated with changes in body weight (between Bdnf DNA methylation and Δ body weight: r=0.59, p=0.018; and between LINE-1 ORF DNA methylation and Δ body weight: =-0.80, p=0.0004). We also observed that noise exposure decreased blood pressure (p=0.038 for SBP, p=0.017 for DBP and p 0. 017 for MAP) and decreased body weight (β=-26g, p=0.008). In conclusion, environmental noise exposures can induce changes in DNA methylation in the brain, which may be associated with adverse effects upon metabolic health through modulation of response to stress-related hormones.
authors.affiliation: Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA. Electronic address: yingqidao@163.com.
authors.forename: Liqiong
authors.initials: L
authors.lastname: Guo
authors.affiliation: School of Environmental Science and Safety Engineering, Tianjin University of Technology, Tianjin 300384, China.
authors.forename: Peng-Hui
authors.initials: PH
authors.lastname: Li
authors.affiliation: Department of Pharmacology, College of Pharmacy, Dalian Medical University, Dalian, Liaoning 116044, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Li
authors.affiliation: Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA.
authors.forename: Elena
authors.initials: E
authors.lastname: Colicino
authors.affiliation: Respiratory Epidemiology, Occupational Medicine and Public Health, Imperial College, London, United Kingdom.
authors.forename: Silvia
authors.initials: S
authors.lastname: Colicino
authors.affiliation: Department of Radiology, No. 531 Hospital of the PLA, Tonghua, Jilin 134000, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wen
authors.affiliation: Department of Radiology, No. 531 Hospital of the PLA, Tonghua, Jilin 134000, China.
authors.forename: Ruiping
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Department of Bioengineering, School of Mineral Processing and Bioengineering, Central South University, Changsha, Hunan 410083, China.
authors.forename: Xiaotian
authors.initials: X
authors.lastname: Feng
authors.affiliation: Northern Institute for Cancer Research, Newcastle University, Newcastle upon Tyne NE2 4HH, United Kingdom.
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Barrow
authors.affiliation: Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA.
authors.forename: Akin
authors.initials: A
authors.lastname: Cayir
authors.affiliation: Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA.
authors.forename: Andrea A
authors.initials: AA
authors.lastname: Baccarelli
authors.affiliation: Harvard T.H. Chan School of Public Health, Boston, MA 02115, USA.
authors.forename: Hyang-Min
authors.initials: HM
authors.lastname: Byun
mesh_terms: D000818:Animals; D001794:Blood Pressure; D001835:Body Weight; D001921:Brain / Q000378:metabolism*; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics; D002394:Catechol O-Methyltransferase / Q000235:genetics; D019175:DNA Methylation; D004781:Environmental Exposure / Q000009:adverse effects; D005786:Gene Expression Regulation; D020084:Long Interspersed Nucleotide Elements; D008297:Male; D009622:Noise / Q000009:adverse effects*; D017208:Rats, Wistar; D044103:Receptor, Melanocortin, Type 2 / Q000235:genetics; D018019:Receptors, Corticotropin-Releasing Hormone / Q000235:genetics; D051844:alpha-Synuclein / Q000235:genetics; D000099052:CRF Receptor, Type 1
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D044103:Receptor, Melanocortin, Type 2; D018019:Receptors, Corticotropin-Releasing Hormone; C497606:Snca protein, rat; D051844:alpha-Synuclein; D000099052:CRF Receptor, Type 1; D002394:Catechol O-Methyltransferase
keywords: Brain; DNA methylation; Environmental noise stress; Epigenetics