Using Lymphocyte and Plasma Hsp70 as Biomarkers for Assessing Coke Oven Exposure among Steel Workers

Abstract

BackgroundHsp70, an early-response protein induced when organisms are confronted with simple or complicated environmental stresses, can act as either a cellular protector or a danger signal.ObjectivesThe goal of this study was to evaluate levels of lymphocyte and/or plasma Hsp70 as biomarkers for assessing exposure response to complex coke oven emissions (COEs).MethodsWe recruited 101 coke oven workers and determined levels of polycyclic aromatic hydrocarbon (PAH) exposure, urinary 1-hydroxypyrene (1-OHP), genotoxic damage by comet assay and micronuclei test, and other markers of damage, including plasma malondialdehyde (MDA) and lactate dehydrogenase (LDH). These were compared to levels of lymphocyte (intra-cellular) and plasma (extracellular) Hsp70 using Western blots and enzyme-linked immunosorbent assays (ELISA), respectively.ResultsWe observed a COEs-related dose-dependent increase in levels of DNA damage, micronuclei rate, MDA concentration, and LDH activity. Lymphocyte Hsp70 levels increased in the intermediate-exposure group (1.39 ± 0.88) but decreased in the high-exposure group (1.10 ± 0.55), compared with the low-exposure group. In contrast, plasma Hsp70 levels progressively increased as the dose of exposure increased. Negative correlations were seen between lymphocyte Hsp70 levels and olive tail moment and LDH activity in the intermediate- and high-exposure groups. However, we observed positive correlations between plasma Hsp70 levels and LDH activity in the low and intermediate groups.ConclusionsIn workers exposed to COEs, high lymphocyte Hsp70 levels may provide protection and high plasma Hsp70 levels may serve as a danger marker. Larger validation studies are needed to establish the utility of Hsp70 as a response marker.

Synergistic Increase of Oxidative Stress and Tumor Markers in PAH-Exposed Workers

“…Most cells contain LDH and when these cells are lethally injured, loss of membrane integrity can be assessed by monitoring activity of LDH in the incubation medium (Kendig and Tarloff, 2007). This is consistent with Yang et al's report that a COEsrelated dose-dependent increase in levels of DNA damage, micronuclei rate, MDA concentration, and LDH activity (Yang et al, 2007). In the present study, PAH significantly activated the GST activity.…”

“…The increase of MDA, LDH and GST is accompanied with the levels of urinary 1-OHP based on the different working environments (Figure 1). Similar results were also observed by Yang et al (2007) and Liu et al (2006). Higher levels of 1-OHP might indicate higher external exposure or faster detoxification process.…”

“…Also, accumulating evidence suggested that ethanol can induce oxidative DNA damage in humans (Zhang et al, 2003;Guo and Ren, 2010). LDH activities were affected by employment time (P=0.022, OR=6.28, 95% CI: 1.31-30.26), this suggest that the longer PAHs exposure may further increase the oxidative stress (Yang et al, 2007).…”

“…The increase of MDA levels have been shown to be a result of lipid peroxidation compared with control group (Yang et al, 2007;Gao et al, 2010). LDH release is commonly used as a marker for necrotic/oncotic cell death (Valentovic and Ball, 1998).…”

Development of stable HSPA1A promoter-driven luciferase reporter HepG2 cells for assessing the toxicity of organic pollutants present in air

“…For example, coke oven emissions collected at a state-run steel company located in northwest China contain as many as 17 PAHs (Yang et al 2007b). Traffic EOM produced a low level increase of relative luciferase activity at non-cytotoxic concentrations in HepG2-luciferase cells.…”