2015年12月，董云偉教授課題組在《Functional Ecology》發表題為“Ecological relevance of energy metabolism: transcriptional responses in energy sensing and expenditure to thermal and osmotic stresses in an intertidal limpet”的研究論文，闡述了多環境因子相互作用對潮間帶生物細胞能量狀態的影響及其生態復雜性。
在自然環境中，生物體會在同一時間內受到多種環境因子的脅迫，這些因子的相互作用會對機體功能產生巨大的影響。而細胞的能量狀態以及代謝調節對脅迫的響應是非常重要的，然而潮間帶生物在應對多種亞致死環境脅迫時能量代謝響應仍不清楚。
本研究通過模擬了自然環境中多種環境因子對生物的交互作用，以帽貝（Cellana toreuma）為研究對象，研究了在高溫、降水和干燥等條件下帽貝細胞內代謝調節和分解代謝相關基因的表達水平的變化。研究結果發現，熱休克蛋白（hsp70），axin（Fu gene inhibition axis formation），代謝感受因子ampk（腺苷酸活化蛋白激酶）和sirt（沉默信息調節因子2相關酶1，5）以及代謝酶己糖激酶（hexokinase），丙酮酸激酶（pyruvate kinase），異檸檬酸脫氫酶（isocitrate dehydrogenase,idh）是非常合適的指示標記，通過其轉錄表達水平上的測定，可用來闡述嫁蟲戚面對高溫、干燥以及雨水刺激下的細胞能量的生理反應狀態。
從基因表達模式以及頻數分布圖來看，高溫、干燥、雨水單一脅迫或者多重環境因子的脅迫都可以引起細胞能量壓力。相比于單一刺激如滲透壓或高溫，多種環境因子的相互作用對細胞能量狀態的影響更為復雜，高溫馴化后的機體應對降水的細胞能量代謝響應降低了可能是由于熱馴化對于機體的影響，帽貝在高溫下的相關能量基因的高表達提供了有效的生理抵抗從而來應對隨后的滲透壓壓力。另一種可能是由于開始的高溫馴化已經接近它們的耐受上限，以至于在面對滲透壓壓力時缺少生理調節能力。如果面對更高的溫度的刺激，滲透壓壓力必然會造成機體能量的缺乏狀態。同時本研究也強調了隨機雨水事件對于細胞壓力以及代謝調節的不利影響，證明能量代謝對機體在面臨多重環境因子脅迫下至關重要的作用。
本文該研究結果于2015年12月發表于英國生態學會旗下期刊《Functional Ecology》（IF=4.828，五年影響因子5.278），ISI Journal Citation Reports? Ranking:2014: 15/144 (Ecology)。（Yunwei Dong*, Shu Zhang, 2015. Ecological relevance of energy metabolism: transcriptional responses in energy sensing and expenditure to thermal and osmotic stresses in an intertidal limpet.Functional ecology,DOI:10.1111/1365-2435.12625.）
論文鏈接：http://onlinelibrary.wiley.com/doi/10.1111/1365-2435.12625/full
Figure 1 Scheme showing the action of metabolic sensors, enzymes involving glycolysis and the tricarboxylic acid cycle (TCA cycle), and heat shock proteins. In low cellular energy status (high AMP/ATP ratio), AMP can induce the upregulation of AXIN, AMP-activated Kinase (AMPK) and Sirtuins (SIRT). AXIN plays an essential role for AMPK activation by orchestrating AMPK and Serine-threonine liver kinase B1 (LKB1) (Zhang et al. 2013).AMPK and SIRT can activate each other. The impact of AMPK and SIRT1 on peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α), estrogen related receptor α (ERRα), forkhead box O (FOXO) and other transcriptional regulators will then affect carbohydrate and lipid metabolism to produce ATP for stress responses (Cantó et al. 2009).
Figure 2 Gene expression of limpets in different treatments and time points. Limpets were acclimated at 18°C and 30°C. After acclimation, limpets were aerially exposed or freshwater sprayed for 2 h for three consecutive days. On each day, three limpets (n = 3) in each treatments were randomly sampled at 16:00 (before aerial exposure/freshwater spray, 0 h), 18:00 (2h after aerial exposure/freshwater spray) and next 08:00 (14 h recovery from aerial exposure/freshwater spray) for measuring gene expressions. The color scale bar indicates log-transformed data, with green indicating downregulation, red indicating upregulation and black indicating no change compared to the median of the control samples.
其他相關閱讀：
1. Dong, Y.W., Han, G.D. & Huang, X.W. (2014) Stress modulation of cellular metabolic sensors: interaction of stress from temperature and rainfall on the intertidal limpet Cellana toreuma.Molecular Ecology, 23, 4541-4554.
2. Han, G.D., Zhang, S., Marshall, D.J., Ke, C.H. & Dong, Y.W. (2013) Metabolic energy sensors (AMPK and SIRT1), protein carbonylation and cardiac failure as biomarkers of thermal stress in an intertidal limpet: linking energetic allocation with environmental temperature during aerial emersion. Journal of Experimental Biology, 216, 3273-3282.
