Real-time PCR assay for detecting illicit steroid administration in veal calves allows reliable biomarker profiling of formalin-fixed, paraffin-embedded (FFPE) archival tissue samples

Transcriptional Biomarkers and Immunohistochemistry for Detection of Illicit Dexamethasone Administration in Veal Calves

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.

Sodium butyrate ameliorates neurotoxicity and exerts anti-inflammatory effects in high fat diet-fed mice

The prevalence of high-fat diet consumption-related disorders is increasing, and it is often associated with oxidative stress, inflammation, and dysregulation in the brain may lead to neurodegenerative diseases (NDDs). Our study aims to evaluate the neuroprotective effects of sodium butyrate (NaB) on HFD-fed mice. In this study, four-week-old male C57Bl/6NTac mice were divided into three groups; the control group, the HFD group, and the HFD + NaB group where mice received 11 mg/kg body weight of NaB with HFD. Western blotting, reverse transcription-PCR, and ELISA were used for biochemical analysis of brain specimens. We found that NaB restored bodyweight and attenuated P-53, Bcl-2-associated X protein (BAX), and caspase cascades in the brains of HFD-fed mice. In addition. NaB reduced the expressions of proinflammatory cytokines and positively modulated antioxidant biomarkers. NaB treatment upregulated the expression of the growth factor-related factors PPARγ, CREB, and BDNF in the brain tissues of HFD-fed mice. Furthermore, we found that NaB significantly ameliorated glucocorticoid receptor and NLRP3 inflammasome expression. Based on our findings, NaB suppressed apoptotic and inflammatory cytokines and enhanced the expression of endogenous antioxidants in brain tissues of HFD-fed mice. Our data strongly suggests that NaB could be utilized as an effective therapeutic agent for NDDs.

A novel tool to screen for treatments with clenbuterol in bovine: Identification of two hepatic markers by metabolomics investigation

Surveillance of illegal use of growth promoters such as β₂-agonists in food producing animals rely on the detection of drug residues by LC-MS/MS. Screening strategies focusing on indirect physiological responses following administration of active compounds are promising approaches to strengthen existing targeted methods and ensure food safety. A metabolomics analysis based on LC-HRMS was carried out on liver extracts from bulls experimentally treated with clenbuterol combined with dexamethasone (n = 8) to mimic a potential anabolic practice, and control animals (n = 8). Nicotinic acid and 5'-deoxy-5'-methylthioadenosine were identified as biomarkers of treatment. Ratio values of such markers to others of the same metabolic pathways (nicotinamide or methionine) were used to develop a classification model to assign animals as treated with clenbuterol or non-treated. The classification model was tested on an external validation set comprising 74 animals either treated with different anabolic compounds (β₂-agonists, sexual steroids, corticosteroid), or non-treated, showing 100% sensitivity and specificity.

Regucalcin expression profiles in veal calf testis: validation of histological and molecular tests to detect sex steroids illicit administration

Background

Sex steroids administration in meat producing animals is forbidden within the EU to preserve consumers’ safety, but continuous monitoring to identify resurgence of their misuse is needed. Among biomarkers related to sex steroids abuse in veal calves the regucalcin (RGN) mRNA perturbations in testis have been described in RNAlater samples. To setup novel diagnostic method, to update current tests available in National Residue Control Plans (NRCPs) and in legal dispute when illicit practices on farm animals are suspected, the reliability of RGN profiling was assessed by histological and molecular techniques.

Methods

Formalin fixed paraffin embedded (FFPE) testis samples, chosen being the most effective preservation strategy adopted by histological NRCPs and allowing easier retrospective analysis if required by legal disputes, were analyzed from veal calves treated with nandrolone, 17β-estradiol and a cocktail of the two hormones. RGN levels were determined by quantitative Real Time PCR and Immunohistochemistry assays. Test performances were assessed and compared by multiple ROC curves.

Results

Both tests resulted sensitive and specific, allowing to enrich, in future field investigation, novel integrated diagnostic protocols needed to unveil sex steroid abuse.

Discussion

Developed RT-qPCR and IHC methods confirmed RGN as a useful and robust biomarker to detect illegal administration of sex steroid hormones in veal calves. The developed methods, successfully applied to ten years old FFPE blocks, could allow both retrospective analysis, when supplementary investigations are requested by authorities, and future implementation of current NRCPs.