BIOCHEMICAL PHARMACOLOGY
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2023
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IF 5.8
Luomin Lin,Yuwei Huang,Jinyi Wang,Xiaocao Guo,Fangjun Yu,Di He,Chuanbin Wu,Lianxia Guo,Baojian Wu
CYP2A5 , an enzyme responsible for metabolism of diverse drugs, displays circadian rhythms in its expression and activity. However, the underlying mechanisms are not fully established. Here we aimed to investigate a potential role of CRY1/2 (circadian clock modulators) in circadian regulation of hepatic CYP2A5. Regulatory effects of CRY1/2 on CYP2A5 were determined using Cry1 -null and Cry2 -null mice, and validated using AML-12, Hepa1-6 and HepG2 cells. CYP2A5 activities both in vivo and in vitro were assessed using coumarin 7-hydroxylation as a probe reaction. mRNA and protein levels were detected by qPCR and western blotting , respectively. Regulatory mechanism was studied using a combination of luciferase reporter assays, chromatin immunoprecipitation (ChIP) and co-immunoprecipitation (Co-IP). We found that ablation of Cry1 or Cry2 in mice reduced hepatic CYP2A5 expression (at both mRNA and protein levels) and blunted its diurnal rhythms. Consistently, these knockouts showed decreased CYP2A5 activity (characterised by coumarin 7-hydroxylation) and a loss of its time-dependency, as well as exacerbated coumarin-induced hepatotoxicity. Cell-based assays confirmed that CRY1/2 positively regulated CYP2A5 expression and rhythms. Based on combined luciferase reporter, ChIP and Co-IP assays, we unraveled that CRY1/2 interacted with E4BP4 protein to repress its inhibitory effect on Cyp2a5 transcription and expression . In conclusion, CRY1/2 regulate rhythmic CYP2A5 in mouse liver through repression of E4BP4. These findings advance our understanding of circadian regulation of drug metabolism and pharmacokinetics .
研究领域:
药理学
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分子生物学
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时间生物学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF PHARMACY AND PHARMACOLOGY
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2023
·Vol. 75
·期 7
·886-897
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IF 3.3
Du Jianhao,Zhang Fugui,Chen Min,Xiao Yifei,Zhang Li,Dong Linlin,Dong Dong,Wu Baojian
ObjectiveDelirium (acute brain syndrome) is a common and serious neuropsychiatric disorder characterized by an acute decline in cognitive function. However, there is no effective treatment clinically. Here we investigated the potential effect of jujuboside A (JuA, a natural triterpenoid saponin) on cognitive impairment in delirium.MethodsDelirium models of mice were established by injecting lipopolysaccharide (LPS) plus midazolam and implementing a jet lag protocol. Novel object recognition test and Y maze test were used to evaluate the effects of JuA on delirium-associated cognitive impairment. The mRNA and protein levels of relevant clock factors and inflammatory factors were measured by qPCR and Western blotting. Hippocampal Iba1+ intensity was determined by immunofluorescence staining.Key findingsJuA ameliorated delirium (particularly delirium-associated cognitive impairment) in mice, which was proved by the behavioural tests, including a preference for new objects, an increase of spontaneous alternation and improvement of locomotor activity. Furthermore, JuA inhibited the expression of ERK1/2, p-p65, TNFα and IL-1β in hippocampus, and repressed microglial activation in delirious mice. This was attributed to the increased expression of E4BP4 (a negative regulator of ERK1/2 cascade and microglial activation). Moreover, loss of E4bp4 in mice abrogated the effects of JuA on delirium as well as on ERK1/2 cascade and microglial activation in the hippocampus of delirious mice. Additionally, JuA treatment increased the expression of E4BP4 and decreased the expression of p-p65, TNFα and IL-1β in LPS-stimulated BV2 cells, supporting a protective effect of JuA on delirium.ConclusionsJuA protects against delirium-associated cognitive impairment through promoting hippocampal E4BP4 in mice. Our findings are of great significance to the drug development of JuA against delirium and related disorders.
研究领域:
神经科学
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药理学
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免疫学
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分子生物学
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产品关联
DOI
PubMed
高影响因子
BIOCHEMICAL PHARMACOLOGY
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2022
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IF 6.1
Min Chen,Yifei Xiao,Fugui Zhang,Jianhao Du,Li Zhang,Yifang Li,Danyi Lu,Zhigang Wang,Baojian Wu
Delirium is a common and serious neuropsychiatric syndrome characterized with acute cognitive and attentional deficits, however, the effective therapies are lacking. Here, using mouse models of delirium, we investigated the effects of tangeretin (TAN, a natural flavonoid) on cognitive impairment by assessing object preference with novel object recognition (NOR) test and spontaneous alternation with Y maze test. We found that TAN, as a RORα/γ agonist, prevented cognitive decline in delirious mice as evidenced by a normal novel object preference and increased spontaneous alternation. This was accompanied by decreased expression of ERK1/2, TNFα and IL-1β as well as diminished microglial activation in delirious mice. The protective effect of TAN on delirium was mainly attributed to increased hippocampal E4BP4 expression (a known target of RORs and a regulator of cognition in delirium through modulating the ERK1/2 cascade and microglial activation) via activation of RORα/γ. In addition, TAN treatment modulated the expression of RORα/γ target genes (such as E4bp4 and Bmal1 ) and inhibited the expression of TNFα and IL-1β in lipopolysaccharide (LPS)-stimulated cells, supporting a beneficial effect of TAN on delirium. In conclusion, TAN is identified as a RORα/γ agonist which promotes E4BP4 expression to prevent cognitive decline in delirious mice. Our findings may have implications for drug development of TAN for prevention and treatment of various diseases associated with cognitive deficiency.
研究领域:
神经科学
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药理学
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免疫学
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分子生物学
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产品关联
DOI
PubMed
高影响因子
MOLECULAR NEUROBIOLOGY
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2025
·Vol. 63
·期 1
·242
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IF 4.3
Yang Yu,Li Xingchang,Gong Shuxian,Sui Lisen,Liu Jian,Yu Fangjun,Zhang Tianpeng
Temporal lobe epilepsy (TLE), the most prevalent form of focal epilepsy and a leading cause of surgically managed intractable cases, is characterized by rhythmic spontaneous seizures that exhibit underutilized therapeutic potential. Here, we aim to uncover the impact of dosing time on the anticonvulsant effect of tiagabine and to elucidate the underlying mechanisms involved. Tiagabine markedly attenuated seizure severity and progression in both acute and chronic models of pilocarpine-induced TLE. Pharmacological effects of tiagabine were found to vary according to dosing time, demonstrating greater efficacy during the light phase compared to the dark phase. This variation in tiagabine efficacy was attributed to diurnal fluctuations in GABAergic neurotransmission, which depends on SLC6A1-dependent GABA reuptake rhythm. Notably, ablation of circadian transcription factor E4bp4 abolished SLC6A1 expression rhythms and abrogated the chronoefficacy of tiagabine. Further, our findings indicated that E4BP4-driven circadian oscillations in SLC6A1 expression regulated the efficacy of tiagabine in a circadian time-dependent manner. These results advocated for chronotherapeutic optimization of tiagabine dosing schedules to align with endogenous SLC6A1 rhythms, offering a promising avenue for precision medicine in the management of TLE. Graphical
研究领域:
神经病学
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时间生物学
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药理学
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癫痫研究
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分子神经科学
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产品关联
DOI
PubMed
高影响因子
XENOBIOTICA
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2021
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IF 1.908
Li Guo,Li Zhang,Haiman Xu,Pei Yu,Zhigang Wang,Danyi Lu,Min Chen,Baojian Wu
1. Retrorsine (RTS) is a pyrrolizidine alkaloid (distributed in many medicinal plants) that has significant hepatotoxicity. Here, we aimed to determine the daily variations in RTS hepatotoxicity (chronotoxicity) in mice, and to investigate the role of metabolism in generating RTS chronotoxicity.2. Acute toxicity and pharmacokinetic studies were performed with mice after RTS administration at different times of the day. Hepatotoxicity was assessed by measuring plasma ALT (alanine aminotransferase) and AST (aspartate aminotransferase) levels. mRNA and proteins were determined by qPCR and Western blotting, respectively. Time-dependent in vitro metabolism of RTS was assessed by using mouse liver microsomes.3. We found that RTS toxicity was more severe in the dark phase (zeitgeber time 14 or ZT14 and ZT18) than in the light phase (ZT2 and ZT6). This chronotoxicity was associated with a dosing time difference in the systemic exposures of RTS and a pyrrolic ester metabolite (a cause of hepatotoxicity, measured by the levels of pyrrole-GSH conjugate and pyrrole-protein adducts due to a high chemical reactivity). Moreover, the CYP3A11 (a major enzyme for RTS bioactivation) inhibitor ketoconazole decreased the production of pyrrole-GSH conjugate and abrogated diurnal rhythm in RTS metabolism. In addition, E4bp4 (a circadian regulator of Cyp3a11) ablation abolished the rhythm of CYP3A11 expression and abrogated the dosing time-dependency of RTS toxicity.4. In conclusion, RTS chronotoxicity in mice was attributed to time-varying hepatic metabolism regulated by the circadian clock. Our findings have implications for reducing pyrrolizidine alkaloid-induced toxicity via a chronotherapeutic approach.
研究领域:
药理学
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毒理学
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时间生物学
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分子生物学
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DOI
PubMed
高影响因子
BIOCHEMICAL PHARMACOLOGY
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2018
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IF 4.235
Mengjing Zhao,Tianpeng Zhang,Fangjun Yu,Lianxia Guo,Baojian Wu
Carboxylesterases (CES) are a family of phase I enzymes that play an important role in xenobiotic clearance and lipid metabolism. Here, we investigate a potential role of E4 promoter-binding protein 4 (E4bp4) in regulation of Ces and CPT-11 (irinotecan, a first-line drug for treating colorectal cancer) pharmacokinetics in mice. Mouse hepatoma Hepa-1c1c7 cells were transfected with Rev-erbα expression plasmid or siRNA targeting E4bp4. The relative mRNA and protein levels of Ces enzymes in the cells or the livers of wild-type and E4bp4-deficient (E4bp4 −/− ) mice were determined by qPCR and Western blotting , respectively. Transcriptional regulation of Ces by E4bp4/Rev-erbα were investigated using luciferase reporter, mobility shift, and co-immunoprecipitation (Co-IP) assays. Pharmacokinetic studies were performed with wild-type and E4bp4 −/− mice after intraperitoneal injection of CPT-11. E4bp4 ablation down-regulated an array of hepatic Ces genes in mice. E4bp4 −/− mice also showed reduced Ces-mediated metabolism and elevated systemic exposure of CPT-11, a well-known Ces substrate. Consistently, E4bp4 knockdown reduced the expression of Ces genes ( Ces2b , Ces2e and Ces2f ) in Hepa-1c1c7 cells. Furthermore, Rev-erbα repressed the transcription of Ces2b, whereas E4bp4 antagonized this repressive action. Co-IP experiment confirmed a direct interaction between E4bp4 and Rev-erbα. Through a combination of promoter analysis and mobility shift assays, we demonstrated that Rev-erbα trans-repressed Ces (Ces2b) through its specific binding to the -767 to-754 bp promoter region. In conclusion, E4bp4 regulates Ces enzymes through inhibition of the transrepression activity of Rev-erbα, thereby impacting the metabolism and pharmacokinetics of Ces substrates.
研究领域:
药理学
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分子生物学
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遗传学
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肝病学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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