Toxicology Centre, University of Saskatchewan, Saskatoon S7N 5B3, Canada.
Department of Plant Protection, College of Food and Agriculture Sciences, King Saud University, P. O. Box 2460, Riyadh 11451, Saudi Arabia.
Environ Sci Technol. 2022 Feb 1;56(3):1820-1829. doi: 10.1021/acs.est.1c05839. Epub 2022 Jan 11.
The epithelial cell layer that lines the gills of fish controls paracellular permeation of chemicals through tight junctions. The integrity of tight junctions can be affected by inflammation, which likely affects the bioavailability of chemicals. Here, the inflammation of the rainbow trout gill cell line RTgill-W1 was induced exposure to bacterial lipopolysaccharides (LPS). Cells were then coexposed to extracts of oil sands process-affected water (OSPW), which contain complex mixtures of chemicals. After 24 h of exposure, cells exposed to LPS showed a reduction in transepithelial electrical resistance, an indicator of tight junction integrity. Quantitative reverse-transcription polymerase chain reaction (RT-PCR) analysis determined that abundances of transcripts of genes coding for tight junction proteins were significantly less in cells exposed to 20, 50, or 100 mg L LPS. Chemical analysis revealed increased permeation of constituents of OSPW across epithelia at all studied LPS concentrations. These in vitro findings were confirmed in vivo in rainbow trout exposed to LPS and OSPW for 48 h, which resulted in greater accumulation of chemicals relative to that for fish exposed to OSPW alone. Our results demonstrated that inflammation and disruption of tight junctions could lead to greater uptake of potentially harmful chemicals from the environment, which has implications for mixture risk assessment.
鱼类鳃上皮细胞层通过紧密连接控制化学物质的旁细胞渗透。紧密连接的完整性可能受到炎症的影响，这可能会影响化学物质的生物利用度。在这里，通过暴露于细菌脂多糖 (LPS) 来诱导虹鳟鱼鳃细胞系 RTgill-W1 的炎症。然后将细胞共同暴露于油砂加工影响水 (OSPW) 的提取物中，其中含有复杂的化学物质混合物。暴露于 LPS 24 小时后，暴露于 LPS 的细胞的跨上皮电阻降低，这是紧密连接完整性的指标。定量逆转录聚合酶链反应 (RT-PCR) 分析确定，暴露于 20、50 或 100 mg L LPS 的细胞中编码紧密连接蛋白的基因的转录本丰度显着降低。化学分析显示，在所有研究的 LPS 浓度下，OSPW 的成分在穿过上皮时的渗透性增加。这些体外发现得到了在暴露于 LPS 和 OSPW 48 小时的虹鳟鱼体内的证实，与单独暴露于 OSPW 的鱼相比，这些鱼体内积累了更多的化学物质。我们的研究结果表明，炎症和紧密连接的破坏可能导致从环境中吸收更多潜在有害的化学物质，这对混合物风险评估具有重要意义。
