Department of Chemistry, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 5B7, Canada.
Department of Chemistry, The University of Western Ontario, 1151 Richmond Street, London, Ontario N6A 5B7, Canada.
J Inorg Biochem. 2018 May;182:222-229. doi: 10.1016/j.jinorgbio.2018.02.009. Epub 2018 Feb 10.
Chromium is a useful heavy metal which has been employed in numerous industry and house applications. However, there are several known health risks associated with its uses. Cr (VI) is a toxic heavy metal format which serves no essential biological role in humans. It has been associated with oxidative stress, cytotoxicity, and carcinogenicity. Contamination of groundwater or soil due to improper handling lead to long term environmental damage. This study explores the effects of long duration chronic exposure to Cr (VI) on live human cells. Herein, scanning electrochemical microscopy (SECM) depth scan imaging was employed to monitor the membrane permeability of single live human bladder cancer (T24) cells following incubation with various Cr (VI) concentration stimuli. SECM was used to provide insights into the long duration effects on membrane homeostasis of individual cells exposed to constant levels of Cr (VI). Further investigation of total population viability was performed by MTT assay. Dependent on the exposure time, transition between three distinct trends was observed. At short incubation times (≤1-3 h) with low concentrations of Cr (VI) (0-10 μM), membrane permeability was largely unaffected. As time increased a decrease in membrane permeability coefficient was observed, reaching a minimum at 3-6 h. Following this a dramatic increase in membrane permeability was observed as cell viability decreased. Higher concentrations were also found to accelerate the timeframe at which these trends occurred. These findings further demonstrate the strength of SECM as a bioanalytical technique for monitoring cellular homeostasis.
铬是一种有用的重金属，在许多工业和家庭应用中都有使用。然而，它的使用也存在一些已知的健康风险。Cr(VI) 是一种有毒的重金属形态，在人体中没有任何必需的生物学作用。它与氧化应激、细胞毒性和致癌性有关。由于处理不当导致地下水或土壤污染会对环境造成长期损害。本研究探讨了长期慢性暴露于 Cr(VI)对活人体细胞的影响。在此，采用扫描电化学显微镜（SECM）深度扫描成像来监测在不同 Cr(VI)浓度刺激下孵育后单个活人体膀胱癌（T24）细胞的膜通透性。SECM 用于深入了解在恒定 Cr(VI)水平下暴露于个体细胞的膜动态平衡的长期影响。通过 MTT 测定进一步研究了总群体活力。根据暴露时间，观察到三种不同趋势之间的转变。在短孵育时间（≤1-3 小时）和低浓度 Cr(VI)（0-10 μM）下，膜通透性基本不受影响。随着时间的推移，观察到膜渗透率系数下降，在 3-6 小时达到最小值。此后，随着细胞活力下降，观察到膜通透性的急剧增加。较高的浓度也被发现加速了这些趋势发生的时间框架。这些发现进一步证明了 SECM 作为监测细胞动态平衡的生物分析技术的优势。
