Toxic Effects of Trichloroethylene on Rat Neuroprogenitor Cells

Abstract

Trichloroethylene (TCE) is a common volatile organic solvent which is considered as an ubiquitous environmental pollutant. It is claimed to be a developmental neurotoxicant. Our group evaluated previously its impact on three-dimensional neurospheres in vitro. The current work aims to investigate the neurotoxic effects of a lower concentration of TCE on the same system. To perform the experiment, neural progenitor cells were obtained from the brains of nine newborn rats. Afterward, these cells were cultured in both growth and differentiation media to get the neurospheres. Cell cultures were divided into two groups: group 1 (control), group 2 (exposed to 0.25 μM TCE). Neurospheres were photographed at different durations and assessment of the morphological changes such as proliferation and differentiation of neurospheres was done. In addition, cell viability, apoptosis, and necrosis were analyzed using flow cytometry to clarify the mechanism of involved cytotoxicity. The results revealed that TCE-treated neurospheres showed significantly decreased proliferation on days 7 and 14. These cells failed to show the neurogenic differentiation seen in the neurospheres of the control group. Furthermore, a highly significant decrease in viability and a significant increase in the number of apoptotic cells were observed in the treated cells in comparison to the control group. The present work confirmed that TCE, at very low doses relevant to daily life exposure in humans, caused neurotoxic effects in 3D neurosphere model through the affection of neural proliferation and differentiation as well as disturbance of cell viability and apoptosis.

Trichloroethylene poses health risks, US EPA confirms

“…Among newer studies identified in the EPA literature search, developmental neurotoxicity was indicated by increased locomotor and exploratory activities were observed following drinking water exposures to mice during nervous system development (Blossom et al, 2013), however these effects were not consistently dose-responsive. A follow-up study from that laboratory (Blossom et al 2016) reported inflammation-mediated cerebellar oxidative stress and increased locomotor activity following gestational TCE exposure in autoimmune-prone mice, while another study demonstrated that TCE reduces cell viability and inhibits differentiation of neural progenitor cells in culture (Salama et al 2018). In addition to the results from (Blossom et al 2016), various indicators of developmental immunotoxicity were also observed in another MRL +/+ mice study (Gilbert et al 2014).…”

Acute Toxicity and Ecotoxicological Risk Assessment of Three Volatile Pesticide Additives on the Earthworm—Eisenia fetida

“…The neurotoxicity, hepatotoxicity, and development toxicity of toluene and xylene has been well documented [ 6 , 7 ]. Trichloroethylene, as a developmental neurotoxicant, can not only disturb the cell viability and induce apoptosis and necrosis, but also affect the neural proliferation, neurite outgrowth, and differentiation [ 8 ]. Additionally, the previous study has documented the toxic effects of certain glyphosate-based formulations (Roundup FG and Mon 8750) on earthworms through lethal toxicity, lysosomal destabilization, and DNA damage [ 9 ].…”