Microsomal epoxide hydrolase (mEH) is a bifunctional protein that plays a central role in the metabolism of numerous xenobiotics as well as mediating the sodium-dependent transport of bile acids into hepatocytes where they are involved in cholesterol excretion and metabolism, lipid digestion and regulating numerous signaling pathways. Previous studies have demonstrated the critical role of GATA-4 and a C/EBPα-NF/Y complex in the regulation of the mEH gene (EPHX1). In this study we show that HNF-4α and CAR/RXR also bind to the proximal promoter region and regulate EPHX1 expression. Bile acids, which inhibit the expression of HNF-4α also decrease the expression of EPHX1. Studies also established that the binding of HNF-4α was essential for the activation of EPHX1 activity by CAR suggesting the formation of a complex between these adjacent factors. The nature of this regulatory complex was further explored using a biotinylated oligonucleotide of this region in conjunction with BioMag beads and mass spectrometric analysis which demonstrated the presence of an additional inhibitory factor (PSF), confirmed by co-immunoprecipitation and ChIP analyses, which interacted with DNA-bound CAR/RXR/HNF-4α forming a 4-component regulatory complex.
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http://dx.doi.org/10.1016/j.bbagrm.2013.05.003 | DOI Listing |
Arch Pharm (Weinheim)
January 2025
Department of Pharmacy, University of Salerno, Fisciano, Italy.
Inhibiting microsomal prostaglandin E synthase-1 (mPGES-1), an inducible enzyme involved in prostaglandin E (PGE) biosynthesis and tumor microenvironment (TME) homeostasis, is a valuable strategy for treating inflammation and cancer. In this work, 5-methylcarboxamidepyrrole-based molecules were designed and synthesized as new compounds targeting mPGES-1. Remarkably, compounds 1f, 2b, 2c, and 2d were able to significantly reduce the activity of the isolated enzyme, showing IC values in the low micromolar range.
View Article and Find Full Text PDFAnim Nutr
December 2024
Guangxi Key Laboratory of Marine Environmental Science, Guangxi Academy of Marine Sciences, Guangxi Academy of Sciences, Nanning 530007, China.
Asian Pac J Cancer Prev
November 2024
Department of Physiology and Biochemistry, School of Medicine, University of Jordan, Amman, Jordan.
Anal Chem
December 2024
Department of Entomology and Nematology and UCD Comprehensive Cancer Center, University of California, Davis, California 95616, United States.
The microsomal epoxide hydrolase (mEH) is important in the detoxification of carcinogens in the liver and other tissues but is also a blood biomarker of hepatitis and liver cancer. Improved analytical methods are needed for the study of its role in the metabolism of xenobiotics and endogenous roles as a blood biomarker of diseases. The development of a double nanobody sandwich ELISA offers significant improvements over traditional polyclonal or monoclonal antibody-based assays, enhancing both the homogeneity and the stability of assay production.
View Article and Find Full Text PDFInsect Sci
October 2024
Guangxi Key Laboratory of Agric-Environment and Agric-Products Safety, College of Agriculture, Guangxi University, Nanning, China.
Juvenile hormones (JHs) play a crucial role in regulating development and reproduction in insects. Most insects predominantly synthesize JH III, which typically involves esterification followed by epoxidation, lepidopteran insects use a pathway of epoxidation followed by esterification. Although hemipteran insects have JH III and JH skipped bisepoxide III (JH SB3), the synthesis pathway and key epoxidases remain unclear.
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