Co-treatment with indole-3-carbinol and resveratrol modify porcine CYP1A and CYP3A activities and expression

Effect of Pregnane X Receptor on CYP3A29 Expression in Porcine Alveolar Macrophages during Mycoplasma hyopneumoniae Infection

Simple Summary

In the currently intense production process, infection of swine with Mycoplasma pneumonia is common in pig farms around the world, and reduction in the feeding efficiency and the growth rate of sick pigs causes considerable economic losses to the pig-rearing industry. Our study aimed to determine the molecular mechanism by which Mycoplasma hyopneumoniae induces inflammation in pigs. Our study showed that Mycoplasma hyopneumoniae can regulate the expression of CYP3A29 by upregulating PXR during the inflammatory response induced in porcine alveolar macrophages. These findings may provide useful information for breeding pigs that are resistant to disease.

Abstract

Mycoplasma hyopneumoniae (M. hyopneumoniae, Mhp) is the causative agent of mycoplasma pneumonia of swine (MPS). M. hyopneumoniae infection causes inflammation in pigs and leads to considerable economic losses in the pig industry. Pregnane X receptor (PXR) is a pluripotent gene regulatory protein that plays an important role in regulating cytochrome P-450 (CYP) in pigs in the context of inflammatory responses, drug metabolism, homeostasis, etc. We previously reported that cytochrome P450 3A29 (CYP3A29) expression was significantly upregulated in pigs infected with M. hyopneumoniae compared with healthy control pigs. This experiment mainly focused on identifying the role of PXR in the regulation of CYP3A29 and inflammatory factors after M. hyopneumoniae infection by establishing pig alveolar macrophage (PAM) cells in which PXR was overexpressed or silenced. Our results showed that the overexpression of PXR could significantly improve the protein and the mRNA expression levels of CYP3A29 with and without M. hyopneumoniae infection in PAM cells. After the expression of PXR was inhibited, protein and mRNA expression levels of CYP3A29 were significantly reduced with and without M. hyopneumoniae infection in PAM cells. Moreover, PXR can regulate the mRNA expression levels of IL-6 and IL-8 during M. hyopneumoniae infection of PAM cells. In conclusion, these results suggest that PXR positively regulates CYP3A29 expression during the inflammatory response caused by M. hyopneumoniae infection.

Porcine cytochrome P450 3A: current status on expression and regulation

The cytochrome P450s (CYPs) constitute a family of enzymes maintaining vital functions in the body and are mostly recognized for their significant role in detoxification. Of the CYP subfamilies, CYP3A, is one of the most active in the clearance of drugs and other xenobiotics. During the last decades, much focus has been on exploring different models for human CYP3A regulation, expression and activity. In that respect, the growing knowledge of the porcine CYP3As is of great interest. Although many aspects of porcine CYP3A regulation and activity are still unknown, the current literature provides a basic understanding of the porcine CYP3As that can be used e.g., when translating results from studies done in the porcine model into human settings. In this review, the current knowledge about porcine CYP3A expression, regulation, activity and metabolic significance are highlighted. Future research needs are also identified.

End-product inhibition of skatole-metabolising enzymes CYP1A, CYP2A19 and CYP2E1 in porcine and piscine hepatic microsomes

The hepatic cytochrome p450 enzymes 1 A, 2A19 and 2E1 is very important for the elimination of skatole from the body of pigs. Impaired skatole metabolism, results in skatole accumulation, which give rise to off flavor of the meat. Several metabolites of skatole has been identified, however the role of these metabolites in the inhibition of the skatole metabolizing enzymes are not documented. Using microsomes from pigs and fish, we determined the ability of several skatole metabolites to inhibit CYP1 A, CYP2A19 and CYP2E1 dependent activity. Our results show that 2-aminoacetophenone is an inhibitor of porcine CYP2A19 and CYP2E1 activity, but not the piscine orthologues. In conclusion, there is species specific differences in the inhibition of CYP1 A and CYP2A19 dependent metabolism of probe substrates. This is relevant to the evaluation of different model systems and to the reduction of off flavor of meat.