Acetylcholinesterase and heat shock protein 70 response in larval brain tissue of Lymantria dispar L. (Lepidoptera, Limantriidae) upon chronic exposure to benzo(a)pyrene

Abstract

The effects of different concentrations of benzo(a)pyrene (BaP) (2, 10, 20, 100, 200, and 2000 ng/g dry food weight) on the activity of acetylcholinesterase (AChE) and concentration of heat-shock protein 70 (hsp70) in fifth instar Lymantria dispar brain tissue were investigated. Inhibition of AChE is a general effect biomarker at the individual level. We observed the most efficient inhibition of this enzyme at medium and high BaP concentrations (20, 100, 200, and 2000 ng/g dry food weight). Western blot analysis revealed the presence of two hsp 70 isoforms, with changed amounts depending on the BaP concentration. A fluctuating response in hsp70 concentration to ingested BaP was observed: with decreased levels in the groups fed 2 and 100 ng BaP/g dry food weight, but increased concentrations in the groups given 10 and 2000 ng/g dry food weight. Even though we detected changes in AChE activity and hsp70 concentration in L. dispar brain tissue upon exposure to different BaP concentrations, we cannot characterize them as sensitive and reliable biomarkers for this xenobiotic in L. dispar caterpillars.

Nickel oxide nanoparticles induce genotoxicity and cellular alterations in the ground beetleBlaps polycresta(Coleoptera: Tenebrionidae)

“…In insects, it was found that the exposure to stressors leads to a decrease in the synthesis rate of most proteins, but HSP expression increases (Augustyniak et al, 2009;Chapuis et al, 2011). Several types of research enlisted HSPs in evaluating the toxic potential of different stressors in insects, particularly heavy metals (Ahamed et al, 2010;Augustyniak et al, 2009;Ilijin et al, 2017).…”

Benzo[a]pyrene-induced changes in carboxylesterase, acetylcholinesterase and heat shock protein 70 of Lymantria dispar (Lepidoptera: Lymantriidae) from unpolluted and polluted forests

“…The concentrations of B[a]P present in host plant species for L. dispar larvae used in our experiment probably were not high enough to influence brain AChE activity in any way. Ilijin et al [50] found that B[a]P present in low concentrations of 2 and 10 ng/g DW in insect diet did not provoke changes in AChE activity of L. dispar larvae from an unpolluted population, and neither did dietary intake of another PAH, fluoranthene, at low and high concentrations (6.7, 33,5 and 67 ng/g DW) [51].…”

“…This type of behavior was observed by Dinan et al [57] during fluoranthene treatment of Drosophila melanogaster cells. Ilijin et al [50] reported that among six tested dietary doses of B[a]P, the largest induction of Hsp70 expression was under the chronic influence of the lowest (2 and 10 ng/g DW) B[a]P concentration. An analogous situation was described in the research of Mrdaković et al [51], where the lowest concentration of fluoranthene (6.7 ng/g DW) caused the greatest elevation of Hsp70 in the brain of L. dispar larvae.…”

Relative gene expression, micronuclei formation, and ultrastructure alterations induced by heavy metal contamination in Pimelia latreillei (Coleoptera: Tenebrionidae) in an urban-industrial area of Alexandria, Egypt

“…In insects, the exposure to stressors leads to a decrease in the rate of synthesis of most proteins, but Hsp expression increases [ 26 , 27 ]. Several studies have implicated heat shock proteins (Hsps) in evaluating the toxic potential of different stressors in insects, particularly of heavy metals [ 26 , 28 ].…”