Journal Article

Mercury Involvement in Neuronal Damage and in Neurodegenerative Diseases

Cariccio, Veronica Lanza, Samà, Annalisa, Mazzon, Emanuela, Bramanti, Placido

2019

Overview

Neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, and multiple sclerosis are characterized by a chronic and selective process of neuronal cell death. Although the causes of neurodegenerative diseases remain still unknown, it is now a well-established idea that more factors, such as genetic, endogenous, and environmental, are involved. Among environmental causes, the accumulation of mercury, a heavy metal considered a toxic agent, was largely studied as a probable factor involved in neurodegenerative disease course. Mercury exists in three main forms: elemental mercury, inorganic mercury, and organic mercury (methylmercury and ethylmercury). Sources of elemental mercury can be natural (volcanic emission) or anthropogenic (coal-fired electric utilities, waste combustion, hazardous-waste incinerators, and gold extraction). Moreover, mercury is still used as an antiseptic, as a medical preservative, and as a fungicide. Dental amalgam can emit mercury vapor. Mercury vapor, being highly volatile and lipid soluble, can cross the blood-brain barrier and the lipid cell membranes and can be accumulated into the cells in its inorganic forms. Also, methylmercury can pass through blood-brain and placental barriers, causing serious damage in the central nervous system. This review describes the toxic effects of mercury in cell cultures, in animal models, and in patients with neurodegenerative diseases. In vitro experiments showed that mercury exposure was principally involved in oxidative stress and apoptotic processes. Moreover, motor and cognitive impairment and neural loss have been confirmed in various studies performed in animal models. Finally, observational studies on patients with neurodegenerative diseases showed discordant data about a possible mercury involvement.

• Publisher: Springer US,Springer Nature B.V
• Subject: Alzheimer disease / Amyotrophic lateral sclerosis / Animal models / Anthropogenic factors / antiseptics / Apoptosis / Biochemistry / Biomedical and Life Sciences / Biotechnology / Blood-brain barrier / Brain damage / Cell culture / Cell death / Cell membranes / Central nervous system / coal / Cognitive ability / cognitive disorders / combustion / Dental amalgams / Dental restorative materials / Dimethylmercury / Disease / disease course / Electric utilities / Fungicides / Gold / hazardous waste / Hazardous wastes / Heavy metals / in vitro studies / Incinerators / Life Sciences / lipids / Mercury / Mercury (metal) / Mercury vapor / Methylmercury / methylmercury compounds / Multiple sclerosis / Neurodegenerative diseases / Neurological diseases / neurons / Nutrition / Observational studies / Oncology / Oxidative stress / Parkinson disease / Parkinson's disease / Patients / Placenta / Preservatives / sclerosis / toxicity / Vapors