Department of Marine Sciences, University of New England, 11 Hills Beach Rd., Biddeford, ME 04005, USA; Department of Integrative Biology, Oklahoma State University, 501 Life Sciences West, Stillwater, OK 74078, USA.
Department of Marine Sciences, University of New England, 11 Hills Beach Rd., Biddeford, ME 04005, USA.
Sci Total Environ. 2015 Apr 15;512-513:201-209. doi: 10.1016/j.scitotenv.2015.01.065. Epub 2015 Jan 24.
Although biomarkers are frequently used to assess sublethal effects of contaminants, a lack of mechanistic linkages to higher-level effects limits the predictive power of biomarkers. Bioenergetics has been proposed as a framework for linking cellular effects to whole-animal effects. We investigated sublethal effects of exposure to wastewater treatment facility effluent in freshwater mussels in situ, thereby capturing ecologically relevant exposure conditions. Our study focused on the energetic biomarker AMP-activated protein kinase (AMPK), while also considering more traditional biomarkers like heat shock proteins (HSP70), and antioxidant enzymes (i.e., superoxide dismutase (SOD), glutathione-S-transferase (GST)). We examined biomarkers at mRNA and protein levels. Effluent exposure caused a reduction in total-AMPK protein abundance (p=0.05) and AMPK mRNA expression (p=0.02). Conversely, AMPK activity increased at downstream sites by 2.2-fold (p=0.05), indicating increased cellular energy consumption. HSP70 protein abundance was lower at downstream sites (p<0.05), while SOD and GST activity levels significantly increased. By using various biomarkers, we demonstrate that exposure to municipal effluent creates an energetically taxing situation. This is the first study to use AMPK to evaluate the effects of contamination in situ, and our results suggest that energetic biomarkers, like AMPK, complement traditional biomarkers and may help establish functional links between cellular and whole-animal effects.
虽然生物标志物经常被用于评估污染物的亚致死效应，但由于缺乏与更高水平效应的机制联系，生物标志物的预测能力有限。生物能量学已被提议作为将细胞效应与整体动物效应联系起来的框架。我们现场调查了暴露于废水处理厂废水中的淡水贻贝的亚致死效应，从而捕获了具有生态相关性的暴露条件。我们的研究集中在能量生物标志物 AMP 激活蛋白激酶（AMPK）上，同时也考虑了更传统的生物标志物，如热休克蛋白（HSP70）和抗氧化酶（即超氧化物歧化酶（SOD）、谷胱甘肽-S-转移酶（GST））。我们检查了 mRNA 和蛋白质水平的生物标志物。废水暴露导致总-AMPK 蛋白丰度降低（p=0.05）和 AMPK mRNA 表达降低（p=0.02）。相反，AMPK 活性在下游部位增加了 2.2 倍（p=0.05），表明细胞能量消耗增加。下游部位 HSP70 蛋白丰度降低（p<0.05），而 SOD 和 GST 活性水平显著增加。通过使用各种生物标志物，我们证明暴露于市政废水会造成能量负担过重的情况。这是首次使用 AMPK 原位评估污染影响的研究，我们的结果表明，能量生物标志物（如 AMPK）补充了传统生物标志物，并可能有助于建立细胞和整体动物效应之间的功能联系。
