Kinkead Ruth A, Elliott Christopher T, Cannizzo Francesca T, Biolatti Bartolomeo, Mooney Mark H
Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 18-30 Malone Road, Belfast, Co. Antrim, BT9 5BN, Northern Ireland,
Anal Bioanal Chem. 2015 Jun;407(15):4495-507. doi: 10.1007/s00216-015-8651-0. Epub 2015 Apr 26.
Growth-promoting agents are continually misused for increasing animal growth and fraudulent gain in the meat industry, yet detection rates from conventional targeted testing for drug residues do not reflect this. This is because testing currently relies on direct detection of drugs or related metabolites and administrators of such compounds can take adaptive measures to avoid detection through the use of endogenous or unknown drugs, and low dose or combined mixtures. New detection methods are needed which focus on the screening of biological responses of an animal to such growth-promoting agents as it has been demonstrated that genomic, proteomic and metabolomics profiles are altered by xenobiotic intake. Therefore, an untargeted proteomics approach using comparative two-dimensional gel electrophoresis (2DE) was carried out to identify putative proteins altered in plasma after treatment with oestradiol, dexamethasone or prednisolone. Twenty-four male cattle were randomly assigned to four groups (n = 6) for experimental treatment over 40 days, namely a control group of non-treated cattle, and three groups administered 17β-oestradiol-3-benzoate (0.01 mg/kg, intramuscular), dexamethasone sodium phosphate (0.7 mg/day, per os) or prednisolone acetate (15 mg/day, per os), respectively. Plasma collected from each animal at day 25 post study initiation was subjected to proteomic analysis by 2DE for comparison of protein expression between treated and untreated animals. Analysis of acquired gel images revealed 22 plasma proteins which differed in expression by more than 50% (p < 0.05) in treated animals compared to untreated animals. Proteins of interest underwent identification by LC-MS/MS analysis and were found to have associated roles in transport, blood coagulation, immune response and metabolism pathways. In this way, seven proteins are highlighted as novel biomarker candidates including transthyretin which is shown to be significantly increased in all treatment groups compared to control animals and potentially may find use as global markers of suspect anabolic practice.
生长促进剂在肉类行业中持续被滥用,以促进动物生长并获取欺诈性收益,但传统的药物残留靶向检测的检出率却无法反映这一情况。这是因为目前的检测依赖于对药物或相关代谢物的直接检测,而此类化合物的使用者可以采取适应性措施,通过使用内源性或未知药物以及低剂量或混合混合物来避免被检测到。需要新的检测方法,重点关注动物对此类生长促进剂的生物反应筛选,因为已证明外源性物质的摄入会改变基因组、蛋白质组和代谢组图谱。因此,采用了一种非靶向蛋白质组学方法,即比较二维凝胶电泳(2DE),以鉴定经雌二醇、地塞米松或泼尼松龙处理后血浆中发生改变的假定蛋白质。将24头雄性牛随机分为四组(每组n = 6),进行为期40天的实验处理,即一组为未处理的对照组,另外三组分别肌肉注射17β - 雌二醇 - 3 - 苯甲酸酯(0.01 mg/kg)、口服地塞米松磷酸钠(0.7 mg/天)或口服醋酸泼尼松龙(15 mg/天)。在研究开始后第25天从每只动物采集的血浆进行2DE蛋白质组分析,以比较处理组和未处理组动物之间的蛋白质表达。对获取的凝胶图像分析显示,与未处理动物相比,处理组动物中有22种血浆蛋白的表达差异超过50%(p < 0.05)。对感兴趣的蛋白质进行液相色谱 - 串联质谱(LC - MS/MS)分析鉴定,发现它们在运输、血液凝固、免疫反应和代谢途径中发挥相关作用。通过这种方式,七种蛋白质被突出作为新的生物标志物候选物,包括甲状腺素运载蛋白,与对照动物相比,它在所有处理组中均显著增加,可能用作可疑合成代谢行为的整体标志物。