Benedetto Alessandro, Biasibetti Elena, Robotti Elisa, Marengo Emilio, Audino Valentina, Bozzetta Elena, Pezzolato Marzia
Istituto Zooprofilattico Sperimentale del Piemonte, Liguria e Valle d'Aosta, Via Bologna 148, 10154 Torino, Italy.
Department of Sciences and Technological Innovation, University of Piemonte Orientale, Viale Michel 11, 15121 Alessandria, Italy.
Foods. 2022 Jun 20;11(12):1810. doi: 10.3390/foods11121810.
Corticosteroids such as Dexamethasone (DEX) are commonly licensed for therapy in meat animals due to their known pharmacological properties. However, their misuse aimed to achieve anabolic effects is often found by National Residues Control Plans. The setup of a complementary "biomarker based" methods to unveil such illicit practices is encouraged by current European legislation. In this study, the combined use of molecular and histological quantitative techniques was applied on formalin fixed paraffin embedded (FFPE) muscle samples to assess the effects of illicit DEX treatment on veal calves. A PCR array, including 28 transcriptional biomarkers related to DEX exposure, was combined with a histochemical analysis of muscle fiber. An analysis based on unsupervised (PCA) and supervised (PLS-DA and Kohonen's SOM) methods, was applied in order to define multivariate models able to classify animals suspected of illicit treatment by DEX. According to the conventional univariate approach, a not-significant reduction in type I fibres was recorded in the DEX-treated group, and only 12 out of 28 targeted genes maintained their expected differential expression, confirming the technical limitations of a quantitative analysis on FFPE samples. However, the multivariate models developed highlighted the possibility to establish complementary screening strategies, particularly when based on transcriptional biomarkers characterised by low expression profiles.
诸如地塞米松（DEX）之类的皮质类固醇因其已知的药理特性而通常被批准用于食用动物的治疗。然而，国家残留控制计划经常发现其为达到合成代谢效果而被滥用的情况。当前的欧洲立法鼓励建立补充性的“基于生物标志物”的方法来揭示此类非法行为。在本研究中，将分子和组织学定量技术结合应用于福尔马林固定石蜡包埋（FFPE）的肌肉样本，以评估非法使用DEX处理对犊牛的影响。一个包含28个与DEX暴露相关的转录生物标志物的PCR阵列与肌肉纤维的组织化学分析相结合。应用基于无监督（主成分分析，PCA）和有监督（偏最小二乘判别分析，PLS - DA和科霍宁自组织映射，Kohonen's SOM）方法的分析，以定义能够对疑似接受DEX非法处理的动物进行分类的多变量模型。根据传统的单变量方法，在DEX处理组中记录到I型纤维没有显著减少，并且28个目标基因中只有12个保持其预期的差异表达，这证实了对FFPE样本进行定量分析的技术局限性。然而，所开发的多变量模型突出了建立补充性筛选策略的可能性，特别是基于具有低表达谱特征的转录生物标志物的策略。
