Environmental toxicants, incidence of degenerative diseases, and therapies from the epigenetic point of view

Abstract

Epigenotoxicology is an emerging field of study that investigates the non-genotoxic epigenetic effects of environmental toxicants resulting in alteration of normal gene expression and disruption of cell function. Recent findings on the role of toxicant-induced epigenetic modifications in the development of degenerative diseases have opened up a promising research direction to explore epigenetic therapy approaches and related prognostic biomarkers. In this review, we presented comprehensive data on epigenetic alterations identified in various diseases, including cancer, autoimmune disorders, pulmonary conditions as well as cardiovascular, gastrointestinal and bone disease. Although data on abnormalities of DNA methylation and their role in the development of diseases are abundant, less is known about the impact of histone modifications and microRNA expressions. Further, we discussed the effects of selected common environmental toxicants on epigenetic modifications and their association with particular abnormalities. A number of different environmental toxicants have been identified for their role in aberrant DNA methylation, histone modifications, and microRNA expression. Such epigenetic effects were shown to be tissue-type specific and highly associated with the level and duration of exposure. Finally, we described present and future therapeutic strategies, including medicines and dietary compounds for combating the toxicant-induced epigenetic alterations. There are currently seven histone deacetylase inhibitors and two DNA methyltransferase inhibitors approved for clinical use and many other promising candidates are in preclinical and clinical testing. Dietary compounds are thought to be the effective and safe strategies for treating and prevention of epigenetic pathophysiological conditions. Still more concentrated epigenetic researches are required for evaluation of chemical toxicity and identifying the causal association between key epigenetic alteration and disease.

Diabetes and Exposure to Environmental Lead (Pb)

“…These long-lasting health effects of early life stresses, can be attributed to specific epigenetic mechanisms such as altered DNA methylation patterns [ 37 ]. Previous studies have shown that exposure to environmental chemicals can induce epigenetic changes that persist for long periods of time and potentially affect physiology and health [ 41 ]. In the context of childhood lead exposure in humans and its potential adult health effects, it is of interest to know if lead exposures induce detectable epigenetic changes of any variety.…”

Expression levels of circulating microRNAs‐126, ‐155, and ‐145 in Mexican women exposed to polycyclic aromatic hydrocarbons through biomass fuel use

“…Recently, an increasing number of scientific investigations have demonstrated that epigenetic alterations play an important role in the onset, establishment, and development of adverse health outcomes associated with environmental exposures (Marsit, 2015;Hodjat et al, 2017;Sun et al, 2018), including CVD (Alegría-Torres et al, 2013;Perez-Vazquez et al, 2017;Sun et al, 2018). Epigenetic changes include DNA methylation, non-coding RNAs (such as microRNAs), chromatin remodeling, and histone modifications (Tammen et al, 2013).…”

Is Silicone Breast Implant Toxicity an Extreme Form of a More Generalized Toxicity Adversely Affecting the Population as a Whole?

“…Stated another way, in the absence of any direct silicon-carbon bonding there is a natural and healthy utilization of silicon in the human body which is devoid of any pathologic biointegration of silicon into essential life-sustaining cellular molecules. Biochemical chaos caused by organosiloxanes also extends to the emerging discipline of epigenotoxicology, which studies adverse effects of environmental toxicants on gene expression and disruption of cell functions via changes in DNA methylation, alterations of histones, and changes to micro RNA (27) . Biophysics research is now capable of circuitously uniting: a) the odor and smell hypersensitivity observed in my breast implant recipients and fibromyalgia patients with b) the TILT observations of Dr. Claudia Miller.…”