The abilities of 22,23-epoxy-2-aza-2,3-dihydrosqualene and the corresponding N-oxide, 22,23-epoxy-2-aza-2,3-dihydrosqualene-N-oxide, to inhibit sterol biosynthesis were studied in microsomes and cells of Saccharomyces cerevisiae and Candida albicans. 22,23-Epoxy-2-aza-2,3-dihydrosqualene, which differs from the other inhibitor only in lacking oxygen at position 2, exhibited higher inhibitory properties in all preparations tested. The different levels of effectiveness of the two azasqualene derivatives were evident mostly in microsomes from S. cerevisiae (the 50 inhibitory concentrations of the 2-aza derivative and the corresponding N-oxide on oxidosqualene cyclase were 30 and 120 microM respectively) and in cell cultures of the same strain (1 order of magnitude separated the inhibitory activities of the two compounds on sterol biosynthesis). A possible explanation for the differences between 22,23-epoxy-2-aza-2,3-dihydrosqualene and the corresponding N-oxide arose from the study of their metabolic fates in vivo and in vitro. While the 2-aza derivative did not undergo any transformation, the N-oxide compound was actively reduced to the corresponding amine in microsomes and in cells of both yeast strains. 22,23-Epoxy-2-aza-2,3-dihydrosqualene-N-oxide seems to behave as a proinhibitor of sterol biosynthesis, becoming active only after transformation into the active form 22,23-epoxy-2-aza-2,3-dihydrosqualene.
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http://dx.doi.org/10.1128/AAC.38.9.1904 | DOI Listing |
Life Metab
December 2024
State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers and Xijing Hospital of Digestive Diseases, Air Force Medical University, Xi'an, Shaanxi 710032, China.
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Department of Hepatology, Center for Pathogen Biology and Infectious Diseases, Institute of Translational Medicine, The First Hospital of Jilin University, Changchun, Jilin, China.
The intricate link between cholesterol metabolism and host immune responses is well recognized, but the specific mechanisms by which cholesterol biosynthesis influences hepatitis B virus (HBV) replication remain unclear. In this study, we show that SREBP2, a key regulator of cholesterol metabolism, inhibits HBV replication by interacting directly with the HBx protein, thereby preventing its nuclear translocation. We also found that inhibiting the ER-to-Golgi transport of the SCAP-SREBP2 complex or blocking SREBP2 maturation significantly enhances HBV suppression.
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Department of Endocrinology, The Second Affiliated Hospital of Anhui Medical University, Hefei Anhui, 230601, China.
Background: The triglyceride-glucose (TyG) index has been identified as an alternative biomarker for insulin resistance (IR), while residual cholesterol (RC) is a simple, cost-effective, and easily detectable lipid metabolite. However, the associations of these two markers with carotid plaque presence remain unclear. Thus, this study aimed to explore their associations with carotid plaque presence.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 2025
Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou 450000, China.
Recent studies have demonstrated that chronic stress can enhance the development of multiple human diseases, including cancer. However, the role of chronic stress in esophageal carcinogenesis and its underlying molecular mechanisms remain unclear. This study uncovered that dysregulated cholesterol metabolism significantly promotes esophageal carcinogenesis under chronic stress conditions.
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January 2025
IrsiCaixa, Badalona, Spain.
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