Gene expression profile associated with thymus regeneration in dexamethasone-treated beef cattle

Abstract

Glucocorticoids (GCs) are illegally used as growth promoters in cattle, and the analytical methods officially applied most likely underestimate the precise frequency of the abuse. As a side effect, the administration of GCs causes fat infiltration, apoptosis, and atrophy of the thymus. However, gross and histological observations carried out previously showed that the thymus preserves an intrinsic ability to regenerate. The aim of this work was to study the transcriptional effects of GCs on genes likely involved in regeneration of the epithelial cell network in the cervical and thoracic thymus of beef cattle treated with dexamethasone (DEX) or prednisolone (PRD) in comparison with a control group. Moreover, the ratio of bax/bcl2 genes was examined to verify a possible antiapoptotic activity occurring at the same time. In the cervical thymus, DEX administration increased the gene expression of c-myc (P < 0.01), tcf3 (P < 0.05), tp63 (P < 0.01), and keratin 5 (krt5; P < 0.01). In the thoracic thymus of DEX-treated cattle, the gene expression of tcf3 (P < 0.01), tp63 (P < 0.01), and krt5 (P < 0.05) was increased. These results suggested that thymic regeneration is underway in the DEX-treated animals. However, the bax/bcl2 ratio was decreased in both cervical and thoracic thymus of DEX-treated cattle (P < 0.01 and P < 0.05, respectively), showing an antiapoptotic effect through the mitochondrial pathway. Conversely, PRD administration caused no change in the expression of all considered genes. These results sustain the hypothesis that regeneration occurs in the thymus parenchyma 6 d after the DEX treatment was discontinued. This hypothesis is also supported by the absence of alterations in the thymus of PRD-treated beef cattle. Indeed, previous studies showed the inability of PRD to induce macroscopic and microscopic lesions in the thymus. Therefore, in this context, it is not surprising that PRD induced no alteration of genes involved in the regeneration pathway.

Tumours in European Shorthair cats: a retrospective study of 680 cases

“…According to the recent literature, 10% of all tumours diagnosed in cats are oral tumours and SCC is the most common; gingiva, the sublingual area and tongue were reported as the most commonly affected sites. 14,15 Comparing our data with data available in the literature, the percentage of mast cell tumours that we detected appeared to be higher than reported in the Swiss study and the most recent UK-based study, but more similar to the study conducted in the USA. 1,2,4 The mean age of occurrence was significantly higher in females compared with males (P = 0.0256).…”

Ameliorative impacts ofAllium cepa Linnaeusaqueous extract against testicular damage induced by dexamethasone

“…In turn, the reduced Bcl‐2 allowed dexamethasone to activate a mitochondrial pathway, initiating apoptosis. Ultimately, we can conclude that treatment with dexamethasone causes apoptosis (Cannizzo et al., 2018).…”

“…Among therapeutic glucocorticoids, dexamethasone is one of the most widely used. It activates the expression of caspases (W. Liu et al., 2018), including caspase‐3 and caspase‐9, and inhibits Bcl‐2 expression to promote apoptosis (Cannizzo et al., 2018). In doing so, dexamethasone inhibits solid tumour and haematologic malignant cell growth, while also suppressing mitogen‐induced proliferation of a wide range of other cell types (Park et al., 2013).…”

Development of a droplet digital PCR assay to detect illicit glucocorticoid administration in bovine

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