DRUG METABOLISM AND DISPOSITION
·
2024
·Vol. 52
·期 11
·1234-1243
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IF 4.4
Yutong Wang,Yixuan Wang,YiTing Hu,QingLiang Wu,Lanlan Gui,Wushuang Zeng,Qi Chen,Tingting Yu,Xinjie Zhang,Ke Lan
Sterol 12α-hydroxylase (CYP8B1) is the unique P450 enzyme with sterol 12-oxidation activity, playing an exclusive role in 12α-hydroxylating intermediates along the bile acid (BA) synthesis pathway. Despite the long history of BA metabolism studies, it is unclear whether CYP8B1 catalyzes 12α-hydroxylation of C27 BAs, the key intermediates shuttling between mitochondria and peroxisomes. This work provides robust in vitro evidence that both microsomal and recombinant CYP8B1 enzymes catalyze the 12α-hydroxylation of dihydroxycoprostanic acid (DHCA) into trihydroxycoprostanic acid (THCA). On the one hand, DHCA 12α-hydroxylation reactivity is conservatively detected in liver microsomes of both human and preclinical animals. The reactivity of human tissue fractions conforms well with the selectivity of CYP8B1 mRNA expression, while the contribution of P450 enzymes other than CYP8B1 is excluded by reaction phenotyping in commercial recombinant enzymes. On the other hand, we prepared functional recombinant human CYP8B1 proteins according to a recently published protocol. Titration of the purified CYP8B1 proteins with either C4 (7α-hydroxy-4-cholesten-3-one) or DHCA yields expected blue shifts of the heme Soret peak (type I binding). The recombinant CYP8B1 proteins efficiently catalyze 12α-hydroxylation of both DHCA and C4, with substrate concentration occupying half of the binding sites of 3.0 and 1.9 μM and kcat of 3.2 and 2.6 minutes−1, respectively. In summary, the confirmed role of CYP8B1 in 12α-hydroxylation of C27 BAs has furnished the forgotten passageway in the BA synthesis pathway. The present finding might have opened a new window to consider the biology of CYP8B1 in glucolipid metabolism and to evaluate CYP8B1 inhibition as a therapeutic approach of crucial interest for metabolic diseases.
研究领域:
生物化学
·
分子生物学
·
药理学
✓ 已验证
DOI
PubMed
高影响因子
DRUG METABOLISM AND DISPOSITION
·
2025
·
IF 4
Yixuan Wang,Tingting Yu,Xinjie Zhang,Yutong Wang,Lanlan Gui,Wushuang Zeng,Liang Huang,Ke Lan
Sterol 12α-hydroxylase (CYP8B1) is a key regulator of bile acid (BA) homeostasis and an emerging therapeutic target for metabolic disorders. To address the challenge of cellular CYP8B1 inhibition characterization, this work developed a pharmacologically optimized HepG2 cells model using triiodothyronine-dexamethasone-bezafibrate (TDB) induction, which significantly enhances the 12α-hydroxylation activity along the acidic pathway of BA biosynthesis in HepG2 cells. Employing stable isotope tracing with apolipoprotein A1-solubilized 2,3,4- 13 C 3 -cholesterol, we established an LC-MS-based flux analysis platform to track de novo BA synthesis. Combined with recombinant CYP8B1 assay, flux analysis revealed CYP8B1 participates in cholic acid synthesis in HepG2 cells, typically via 12α-hydroxylation of 7α-hydroxy-3-oxo-4-cholestenoic acid and dihydroxycholestanoic acid. In TDB-HepG2 cells, azole antifungals exhibited differentiated inhibition of 12α-hydroxylation activity, generally mirroring the enzymatic data. Econazole acted as a relatively selective CYP8B1 inhibitor with cellular half maximal inhibitory concentration of 0.31-0.45 μM, tioconazole and posaconazole dually inhibited CYP8B1 and sterol 27-hydroxylase (CYP27A1), itraconazole and voriconazole primarily inhibited CYP27A1, and fluconazole showed no activity toward either enzyme. This study provides the first direct evidence that CYP8B1 participates in cholic acid synthesis via acidic pathway and establishes a high-throughput cellular platform for screening CYP8B1 inhibitors, revealing azoles as effective modulators of this pathway.
研究领域:
分子生物学
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药物代谢
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肝脏病学
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代谢组学
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生物化学
·
药理学
·
细胞生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
EUROPEAN JOURNAL OF PHARMACOLOGY
·
2018
·
IF 3.04
Yulong Kong,Xiaoguang Gao,Changyuan Wang,Chenqing Ning,Kexin Liu,Zhihao Liu,Huijun Sun,Xiaodong Ma,Pengyuan Sun,Qiang Meng
Accumulation of toxic bile acids in liver could cause cholestasis and liver injury. The purpose of the current study is to evaluate the hepatoprotective effect of yangonin , a product isolated from an edible botanical Kava against lithocholic acid (LCA)-induced cholestasis, and further to elucidate the involvement of farnesoid X receptor (FXR) in the anticholestatic effect using in vivo and in vitro experiments. The cholestatic liver injury model was established by intraperitoneal injections of LCA in C57BL/6 mice. Serum biomarkers and H&E staining were used to identify the amelioration of cholestasis after yangonin treatment. Mice hepatocytes culture, gene silencing experiment, real-time PCR and Western blot assay were used to elucidate the mechanisms underlying yangonin hepatoprotection . The results indicated that yangonin promoted bile acid efflux and reduced hepatic uptake via an induction in FXR-target genes Bsep , Mrp2 expression and an inhibition in Ntcp , all of which are responsible for bile acid transport. Furthermore, yangonin reduced bile acid synthesis through repressing FXR-target genes Cyp7a1 and Cyp8b1, and increased bile acid metabolism through an induction in gene expression of Sult2a1, which are involved in bile acid synthesis and metabolism. In addition, yangonin suppressed liver inflammation through repressing inflammation-related gene NF-κB, TNF-α and IL-1β. In vitro evidences showed that the changes in transporters and enzymes induced by yangonin were abrogated when FXR was silenced. In conclusions, yangonin produces protective effect against LCA-induced hepatotoxity and cholestasis due to FXR-mediated regulation. Yangonin may be an effective approach for the prevention against cholestatic liver diseases.
研究领域:
药理学
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肝病学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIOCHEMICAL PHARMACOLOGY
·
2017
·
IF 4.581
Xiaoguang Gao,Ting Fu,Changyuan Wang,Chenqing Ning,Yulong Kong,Zhihao Liu,Huijun Sun,Xiaodong Ma,Kexin Liu,Qiang Meng
Recently obeticholic acid (OCA) which is a farnesoid X receptor (FXR) agonist was approved by FDA to treat cholestatic liver diseases, which provided us a novel therapeutic strategy against cholestasis . Herein, we used a novel computational strategy with two-dimensional virtual screening for FXR agonists. For the first time, we found that auraptene (AUR), a natural product, can activate FXR to exert hepatoprotective effect against cholestatic liver injury in vivo and in vitro . Importantly, AUR was found to significantly decrease the mortality of cholestatic mice. Dynamic change analysis of bile acids and gene analysis revealed that AUR promoted bile acid efflux from liver into intestine via an induction in FXR-target genes Bsep and Mrp2 expression, and reduced hepatic uptake through an inhibition in Ntcp . Furthermore, AUR reduced bile acid synthesis through repressing FXR-target genes Cyp7a1 and Cyp8b1, and increased bile acid metabolism through an induction in Sult2a1 . In addition, AUR promoted liver repair through an induction in liver regeneration-related gene, and suppressed liver inflammation through repressing inflammation-related gene NF-κB, TNF-α, IL-1β and IL-6. However, the changes in these genes and protein, as well as ameliorative liver histology induced by AUR were abrogated by FXR antagonist guggulsterone in vivo and FXR siRNA in vitro . These findings suggest that AUR may be an effective approach for the prevention against cholestatic liver diseases.
研究领域:
药理学
·
肝病学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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