Cellular Stress Pathways Are Linked to Acetamiprid-Induced Apoptosis in SH-SY5Y Neural Cells

Abstract

Acetamiprid (ACE), a commonly used neonicotinoid insecticide, is correlated with neurological symptoms, immunotoxicity and hepatotoxicity. Cellular stress and damage could play an important role in ACE-induced neurotoxicity; however, its mechanism has not been fully understood. We evaluated the effects of ACE on oxidative stress, endoplasmic reticulum (ER) stress, cellular death, mRNA expression levels of related genes and protein expressions of related molecular mechanisms in SH-SY5Y human neuroblastoma cells. The half maximal inhibition of enzyme activity (IC50) value of ACE was determined as 4.26 mM after 24 h of treatment by MTT assay. We revealed an increase in reactive oxygen species (ROS) production and calcium release. Significant increases were measured in inositol-requiring enzyme 1-alpha (IRE1-α) and binding immunoglobulin protein 90 (GRP90) levels as well as mRNA expression levels of caspase 3, 4 and 9 genes indicating enhanced ER stress. Apoptosis and ER stress-related genes were significantly upregulated at ≥2 mM. Indeed, ACE caused apoptosis and necroptosis while necrosis was not observed. There was a significant increase in the protein level of mitogen-activated protein kinase-8 (MAPK8) at 4 mM of ACE while no change was seen for nuclear factor kappa-B (NF-κB) and tumor necrosis factor-alpha (TNF-α). In conclusion, increased cellular stress markers could be proposed as an underlying mechanism of ACE-induced cell death in neural cells.

Statement on the toxicological properties and maximum residue levels of acetamiprid and its metabolites

“…From the systematic literature review, eight studies were selected as relevant: five were conducted in vitro and three in zebrafish embryos. Two in vitro studies were not evaluated in detail (Cheng et al., 2020 ; Öztaş et al., 2021 ), due to the lack of relevance of the test systems as identified during the study appraisal. For more details on the studies, see Appendix 5 .…”

The SH-SY5Y human neuroblastoma cell line, a relevant in vitro cell model for investigating neurotoxicology in human: Focus on organic pollutants

“…Acetamiprid and imidacloprid, among other neonicotinoids, caused a concentration-dependent decrease in cell metabolic activities and/or growth rate (due to the triggering of apoptosis) through several mechanisms shared by other pesticides: oxidative stress (increased intracellular ROS levels) and DNA damage [73,131,132] (Supplementary Table 2). Effects of neonicotinoids on growth rate might be potentiated by the commercial formulation of the compounds, as shown in the case of imidacloprid [73].…”

“…Effects of neonicotinoids on growth rate might be potentiated by the commercial formulation of the compounds, as shown in the case of imidacloprid [73]. In addition, neonicotinoids could trigger ER-stress as shown in the case of acetamiprid inducing, at the mRNA level, ER-stress related proteins inositol requiring enzyme 1-𝛼 (IRE1-𝛼) and binding immunoglobulin protein 90 (GRP90) [131].…”

Therapeutic Candidates for Alzheimer’s Disease: Saponins

“…Mitochondrial damage induces the release of Cyt-c and other apoptotic factors into the cytoplasm, which then activate caspase-9 and caspase-3, resulting in apoptosis [ 220 ]. The B-cell lymphoma-2 (Bcl-2) protein family includes proapoptotic proteins, BCL2-associated X (BAX), Bcl-2 antagonist killer 1 (BAK), Bcl-2-like protein 11 (BIM), p53 upregulated modulator of apoptosis (PUMA), and Bcl2 modifying factor (BMF), and antiapoptotic proteins, such as Bcl-2, lymphoma-extra-large (Bcl-xL), Bcl-2 like 2 (Bcl-w), and myeloid cell leukemia-1 (Mcl-1), which tightly regulates this apoptotic process by controlling the ratio of proapoptotic and antiapoptotic proteins [ 221 , 222 ], particularly the Bax/Bcl-2 ratio [ 223 ]. In AD patients, Bcl-2 expression is reduced in the hippocampus [ 224 ], while Bax accumulates near senile plaques and tau protein fiber tangles in an AD animal model, suggesting that mitochondria-mediated apoptosis is closely linked to the pathology of AD [ 225 ].…”