Collagen degradation assessment with an in vitro rotator cuff tendinopathy model using multiparametric ultrashort-TE magnetization transfer (UTE-MT) imaging.

PURPOSE: This study aims to assess ultrashort-TE magnetization transfer (UTE-MT) imaging of collagen degradation using an in vitro model of rotator cuff tendinopathy. METHODS: Thirty-six supraspinatus tendon specimens were divided into three groups and treated with 600 U collagenase (Group 1), 150 U collagenase (Group 2), and phosphate buffer saline (Group 3). UTE-MT imaging was performed to assess changes in macromolecular fraction (MMF), macromolecule transverse relaxation time (T2m), water longitudinal relaxation rate constant (R1m), the magnetization exchange rate from the macromolecular to water pool (Rm0 w) and from water to the macromolecular pool (Rm0 m), and magnetization transfer ratio (MTR) at baseline and following digestion and their differences between groups. Biochemical and histological studies were conducted to determine the extent of collagen degradation. Correlation analyses were performed with MMF, T2m, R1m, Rm0 w, Rm0 m, and MTR, respectively. Univariate and multivariate linear regression analyses were performed to evaluate combinations of UTE-MT parameters to predict collagen degradation. RESULTS: MMF, T2m, R1m, Rm0 m, and MTR decreased after digestion. MMF (r = -0.842, p < 0.001), MTR (r = -0.78, p < 0.001), and Rm0 m (r = -0.662, p < 0.001) were strongly negatively correlated with collagen degradation. The linear regression model of differences in MMF and Rm0 m before and after digestion explained 68.9% of collagen degradation variation in the tendon. The model of postdigestion in MMF and T2m and the model of MTR explained 54.2% and 52.3% of collagen degradation variation, respectively. CONCLUSION: This study highlighted the potential of UTE-MT parameters for evaluation of supraspinatus tendinopathy.

Genetic variants, haplotype determination, and function of novel alleles of CYP2B6 in a Han Chinese population.

Amino acid variants in protein may result in deleterious effects on enzymatic activity. In this study we investigate the DNA variants on activity of CYP2B6 gene in a Chinese Han population for potential use in precision medicine. All exons in CYP2B6 gene from 1483 Chinese Han adults (Zhejiang province) were sequenced using Sanger sequencing. The effects of nonsynonymous variants on recombinant protein catalytic activity were investigated in vitro with Sf12 system. The haplotype of novel nonsynonymous variants with other single nucleotide variants in the same allele was determined using Nanopore sequencing. Of 38 alleles listed on the Pharmacogene Variation Consortium, we detected 7 previously reported alleles and 18 novel variants, of which 11 nonsynonymous variants showed lower catalytic activity (0.00-0.60) on bupropion compared to CYP2B6*1. Further, these 11 novel star-alleles (CYP2B6*39-49) were assigned by the Pharmacogene Variation Consortium, which may be valuable for pharmacogenetic research and personalized medicine.

Identification and Functional Assessment of Eight CYP3A4 Allelic Variants *39-*46 Detected in the Chinese Han Population.

Cytochrome P450 3A4 (CYP3A4), a key enzyme, is pivotal in metabolizing approximately half of the drugs used clinically. The genetic polymorphism of the CYP3A4 gene significantly influences individual variations in drug metabolism, potentially leading to severe adverse drug reactions (ADRs). In this study, we conducted a genetic analysis on CYP3A4 gene in 1163 Chinese Han individuals to identify the genetic variations that might affect their drug metabolism capabilities. For this purpose, a multiplex polymerase chain reaction (PCR) amplicon sequencing technique was developed, enabling us to perform the genotyping of CYP3A4 gene efficiently and economically on a large scale. As a result, a total of 14 CYP3A4 allelic variants were identified, comprising six previously reported alleles and eight new nonsynonymous variants that were nominated as new allelic variants *39-*46 by the PharmVar Association. Further, functional assessments of these novel CYP3A4 variants were undertaken by coexpressing them with cytochromes P450 oxidoreductase (CYPOR) in Saccharomyces cerevisiae microsomes. Immunoblot analysis indicated that with the exception of CYP3A4.40 and CYP3A4.45, the protein expression levels of most new variants were similar to that of the wild-type CYP3A4.1 in yeast cells. To evaluate their catalytic activities, midazolam was used as a probe drug. The results showed that variant CYP3A4.45 had almost no catalytic activity, whereas the other variants exhibited significantly reduced drug metabolism abilities. This suggests that the majority of the CYP3A4 variants identified in the Chinese population possess markedly altered capacities for drug metabolism. SIGNIFICANCE STATEMENT: In this study, we established a multiplex polymerase chain reaction (PCR) amplicon sequencing method and detected the maximum number of new CYP3A4 variants in a single ethnic population. Additionally, we performed the functional characterizations of these eight novel CYP3A4 allele variants in vitro. This study not only contributes to the understanding of CYP3A4 genetic polymorphism in the Chinese Han population but also holds substantial reference value for their potential clinical applications in personalized medicine.

Liensinine reduces acute lung injury brought on by lipopolysaccharide by inhibiting the activation of the NF-κB signaling pathway through modification of the Src/TRAF6/TAK1 axis.

ALI is characterized by macrophage-driven inflammation, causing severe lung damage. Currently, there are limited therapeutic options available for ALI. Liensinine (LIEN), with known anti-inflammatory properties, lacks extensive study in the ALI context. This study aimed to investigate the impact of LIEN on ALI and elucidate its molecular mechanisms. A total of thirty-six male BALB/c mice altogether were split into six groups: Control, LPS (10 mg/kg), Low (10 mg/kg LIEN + 10 mg/kg LPS), Middle (20 mg/kg LIEN + 10 mg/kg LPS), High (40 mg/kg LIEN + 10 mg/kg LPS), and DEX (2 mg/kg DEX + 10 mg/kg LPS). Lung tissue injury, pulmonary edema, and inflammatory factor levels were evaluated in lung tissues and LPS-stimulated bone marrow-derived macrophages (BMDM). TAK1 activation, TRAF6 ubiquitination, and their interactions were assessed to understand the involved molecular mechanisms. LIEN treatment ameliorated lung tissue injury and suppressed LPS-induced inflammatory factor levels in lung tissues and BMDM. Mechanistically, LIEN inhibited TAK1 activation by disrupting TRAF6-TAK1 interactions, limiting p65's nuclear translocation, and reducing the release of inflammatory factors. According to network pharmacology and molecular docking, LIEN most likely prevents inflammation by interfering directly with the Src. Overexpression of Src in BMDM abolished the regulation of TRAF6 by LIEN, supporting the involvement of the Src/TRAF6/TAK1 axis in its mechanism of action. Based on this study, LIEN treats ALI by modifying the Src/TRAF6/TAK1 axis and blocking the activation of the NF-κB pathway, regulating the release of inflammatory factors. These findings highlight the promise of LIEN as a prospective therapeutic option for the treatment of ALI.

Optimisation of warfarin-dosing algorithms for Han Chinese patients with CYP2C9*13 variants.

BACKGROUND: Existing pharmacogenetic algorithms cannot fully explain warfarin dose variability in all patients. CYP2C9*13 is an important allelic variant in the Han Chinese population. However, adjustment of warfarin dosing in CYP2C9*13 variant carriers remains unclear. To the best of our knowledge, this study is the first to assess the effects of adjusting warfarin dosages in Han Chinese patients harbouring CYP2C9*13 variants. METHODS: In total, 971 warfarin-treated Han Chinese patients with atrial fibrillation were enrolled in this study. Clinical data were collected, and CYP2C9*2, *3, *13 and VKORC1-1639 G > A variants were genotyped. We quantitatively analysed the effect of CYP2C9*13 on warfarin maintenance dose and provided multiplicative adjustments for CYP2C9*13 using validated pharmacogenetic algorithms. RESULTS: Approximately 0.6% of the Han Chinese population carried CYP2C9*13 variant, and the genotype frequency was between those of CYP2C9*2 and CYP2C9*3. The warfarin maintenance doses were significantly reduced in CYP2C9*13 carriers. When CYP2C9*13 variants were not considered, the pharmacogenetic algorithms overestimated warfarin maintenance doses by 1.03-1.16 mg/d on average. The actual warfarin dose in CYP2C9*13 variant carriers was approximately 40% lower than the algorithm-predicted dose. Adjusting the warfarin-dosing algorithm according to the CYP2C9*13 allele could reduce the dose prediction error. CONCLUSION: Our study showed that the algorithm-predicted doses should be lowered for CYP2C9*13 carriers. Inclusion of the CYP2C9*13 variant in the warfarin-dosing algorithm tends to predict the warfarin maintenance dose more accurately and improves the efficacy and safety of warfarin administration in Han Chinese patients.

Effects of bergapten on the pharmacokinetics of macitentan in rats both in vitro and in vivo.

Macitentan was approved by the United States Food and Drug Administration (FDA) in 2013 for the treatment of pulmonary arterial hypertension (PAH). Bergapten is a furanocoumarin that is abundant in Umbelliferae and Rutaceae plants and is widely used in many Chinese medicine prescriptions. Considering the possible combination of these two compounds, this study is aimed to investigate the effects of bergapten on the pharmacokinetics of macitentan both in vitro and in vivo. Rat liver microsomes (RLMs), human liver microsomes (HLMs), and recombinant human CYP3A4 (rCYP3A4) were used to investigate the inhibitory effects and mechanisms of bergapten on macitentan in vitro. In addition, pharmacokinetic parameters were also studied in vivo. Rats were randomly divided into two groups (six rats per group), with or without bergapten (10 mg/kg), and pretreated for 7 days. An oral dose of 20 mg/kg macitentan was administered to each group 30 min after bergapten or 0.5% CMC-Na administration on day 7. Blood was collected from the tail veins, and the plasma concentrations of macitentan and its metabolites were assessed by ultra-performance liquid chromatography - tandem mass spectrometer (UPLC-MS/MS). Finally, we analyzed the binding force of the enzyme and two small ligands by in silico molecular docking to verify the inhibitory effects of bergapten on macitentan. The in vitro results revealed that the IC50 values for RLMs, HLMs, and rCYP3A4 were 3.84, 17.82 and 12.81 µM, respectively. In vivo pharmacokinetic experiments showed that the AUC(0-t), AUC(0-∞), and Cmax of macitentan in the experimental group (20,263.67 µg/L*h, 20,378.31 µg/L*h and 2,999.69 µg/L, respectively) increased significantly compared with the control group (7,873.97 µg/L*h, 7,897.83 µg/L*h and 1,339.44 µg/L, respectively), while the CLz/F (1.07 L/h/kg) of macitentan and the metabolite-parent ratio (MR) displayed a significant decrease. Bergapten competitively inhibited macitentan metabolism in vitro and altered its pharmacokinetic characteristics in vivo. Further molecular docking analysis was also consistent with the experimental results. This study provides a reference for the combined use of bergapten and macitentan in clinical practice.

Characterization of 15 CYP2J2 variants identified in the Chinese Han population on the metabolism of ebastine and terfenadine in vitro.

Genetic polymorphism of the cytochrome P450 (CYP) gene can significantly influence the metabolism of endogenous and xenobiotic compounds. However, few studies have focused on the polymorphism of CYP2J2 and its impact on drug catalytic activity, especially in the Chinese Han population. In this study, we sequenced the promoter and exon regions of CYP2J2 in 1,163 unrelated healthy Chinese Han individuals using the multiplex PCR amplicon sequencing method. Then, the catalytic activities of the detected CYP2J2 variants were evaluated after recombinant expression in S. cerevisiae microsomes. As a result, CYP2J2*7, CYP2J2*8, 13 variations in the promoter region and 15 CYP2J2 nonsynonymous variants were detected, of which V15A, G24R, V68A, L166F and A391T were novel missense variations. Immunoblotting results showed that 11 of 15 CYP2J2 variants exhibited lower protein expression than wild-type CYP2J2.1. In vitro functional analysis results revealed that the amino acid changes of 14 variants could significantly influence the drug metabolic activity of CYP2J2 toward ebastine or terfenadine. Specifically, 4 variants with relatively higher allele frequencies, CYP2J2.8, 173_173del, K267fs and R446W, exhibited extremely low protein expression and defective catalytic activities for both substrates. Our results indicated that a high genetic polymorphism of CYP2J2 could be detected in the Chinese Han population, and most genetic variations in CYP2J2 could influence the expression and catalytic activity of CYP2J2. Our data significantly enrich the knowledge of genetic polymorphisms in CYP2J2 and provide new theoretical information for corresponding individualized medication in Chinese and other Asian populations.

Liensinine, a alkaloid from lotus plumule, mitigates lipopolysaccharide-induced sepsis-associated encephalopathy through modulation of nuclear factor erythroid 2-related factor-mediated inflammatory biomarkers and mitochondria apoptosis.

The present study aims to investigate the role of liensinine in life-threatened sepsis-associated encephalopathy (SAE) mice and the underlying mechanism. Here, seventy-two mice were divided into six groups, including the control group, SAE group, liensinine-treated group, and three doses of liensinine-treated SAE groups. Lipopolysaccharide triggered cerebrum necrosis and disrupted the integrity and permeability of blood-brain barrier (BBB). While liensinine restored cerebrum structure and improved BBB integrity with upregulated tight junction proteins, decreased evans blue leakage and fibrinogen expression with decreased matrix metalloproteinases 2/9 in serum, thereby reducing BBB permeability. Moreover, lipopolysaccharide triggered cerebrum oxidative stress and inflammation, whereas liensinine enhanced antioxidant enzymes activities and weakened malondialdehyde through nuclear factor erythroid 2-related factor. Meanwhile, liensinine inhibited inflammation by activating inducible nitric oxide synthase. Tunel staining combined with transmission electron microscope indicated that lipopolysaccharide induced cerebrum apoptosis, whereas liensinine blocked apoptosis through decreasing B-cell lymphoma-2 associated X (Bax) expression and cytochrome C (Cyto-c) release, increasing B-cell lymphoma-2 (Bcl-2) expression, blocking apoptosome assembly, inhibiting caspase-3 activation, thereby suppressing intrinsic mitochondria apoptosis. Recovering of inflammatory homeostasis and inhibition of mitochondria apoptosis by liensinine ultimately restored cognitive function in SAE mice. Altogether, liensinine attenuated lipopolysaccharide-induced SAE via modulation of Nrf2-mediated inflammatory biomarkers and mitochondria apoptosis.

Identification and in vitro functional assessment of 10 CYP2C9 variants found in Chinese Han subjects.

Cytochrome P450 2C9 (CYP2C9) participates in about 15% of clinical drug metabolism, and its polymorphism is associated with individual drug metabolism differences, which may lead to the adverse drug reactions (ADRs). In this study, 1163 Chinese Han individuals were recruited to investigate their distribution pattern of CYP2C9 gene and find out the variants that may affect their drug metabolic activities. We successfully developed a multiplex PCR amplicon sequencing method and used it for the genetic screening of CYP2C9 in a large scale. Besides the wild type CYP2C9*1, totally 26 allelic variants of CYP2C9 were detected, which included 16 previously reported alleles and 10 new non-synonymous variants that had not been listed on the PharmVar website. The characteristics of these newly detected CYP2C9 variants were then evaluated after co-expressing them with CYPOR in S. cerevisiae microsomes. Immunoblot analysis revealed that except for Pro163Ser, Glu326Lys, Gly431Arg and Ile488Phe, most of newly detected variants showed comparable protein expression levels to wild type in yeast cells. Two typical CYP2C9 probe drugs, losartan and glimepiride, were then used for the evaluation of metabolic activities of variants. As a result, 3 variants Thr301Met, Glu326Lys, and Gly431Arg almost lost their catalytic activities and most of other variants exhibited significantly elevated activities for drug metabolism. Our data not only enriches the knowledge of naturally occurring CYP2C9 variants in the Chinese Han population, but also provides the fundamental evidence for its potential clinical usage for personalized medicine in the clinic.

Inhibitory effect of Schisandrin on the pharmacokinetics of poziotinib in vivo and in vitro by UPLC-MS/MS.

BACKGROUND: As a pan-HER tyrosine kinase inhibitor with a promising application prospect, poziotinib is likely to be coadministered with Schisandrins in clinical treatment due to its anticancer activities. METHODS: Eighteen Sprague-Dawley rats were randomly divided into three groups: Schisandrin A group and Schisandrin B group (20 mg/kg daily for 1 week), and control group (vehicle). On day 8, poziotinib (2 mg/kg) was administered by oral gavage 30 min later. An in vitro study was developed to identify the possible mechanisms of Schisandrins on poziotinib metabolism. All analytes were detected by UPLC/MS-MS, and molecular docking was performed by AutoDock Tools. RESULTS: When rats were preadministered with Schisandrin A, AUC(0-∞) and Cmax of poziotinib were obviously increased by 0.79- and 1.17-fold, whereas the Vz/F and CLz/F values were dramatically decreased. The results in Schisandrin B group presented similarly. Both Schisandrin A and Schisandrin B were mixed inhibitors of poziotinib in RLMs, and Schisandrin B showed stronger inhibitory activity with IC50 values of 2.55 µM for M1 and 6.97 µM for M2. Molecular docking analysis demonstrated that Schisandrin A and Schisandrin B exhibited a strong binding ability towards CYP2D6 as compared to CYP3A4. CONCLUSION: All results provided the direct evidence of the pharmacokinetic drug-drug interactions (DDIs) between Schisandrin and poziotinib. Thus, particular attention should be paid when poziotinib is taken together with Schisandrins in clinical practice.

Assessments of CYP­inhibition­based drug-drug interaction between vonoprazan and poziotinib in vitro and in vivo.

CONTEXT: Poziotinib and vonoprazan are two drugs mainly metabolized by CYP3A4. However, the drug-drug interaction between them is unknown. OBJECTIVE: To study the interaction mechanism and pharmacokinetics of poziotinib on vonoprazan. MATERIALS AND METHODS: In vitro experiments were performed with rat liver microsomes (RLMs) and the contents of vonoprazan and its metabolite were then determined with UPLC-MS/MS after incubation of RLMs with vonoprazan and gradient concentrations of poziotinib. For the in vivo experiment, rats in the poziotinib treated group were given 5 mg/kg poziotinib by gavage once daily for 7 days, and the control group was only given 0.5% CMC-Na. On Day 8, tail venous blood was collected at different time points after the gavage administration of 10 mg/kg vonoprazan, and used for the quantification of vonoprazan and its metabolite. DAS and SPSS software were used for the pharmacokinetic and statistical analyses. RESULTS: In vitro experimental data indicated that poziotinib inhibited the metabolism of vonoprazan (IC50 = 10.6 µM) in a mixed model of noncompetitive and uncompetitive inhibition. The inhibitory constant Ki was 0.574 µM and the binding constant αKi was 2.77 µM. In vivo experiments revealed that the AUC(0-T) (15.05 vs. 90.95 µg/mL·h) and AUC(0-∞) (15.05 vs. 91.99 µg/mL·h) of vonoprazan increased significantly with poziotinib pretreatment. The MRT(0-∞) of vonoprazan increased from 2.29 to 5.51 h, while the CLz/F value decreased from 162.67 to 25.84 L/kg·h after pretreatment with poziotinib. CONCLUSIONS: Poziotinib could significantly inhibit the metabolism of vonoprazan and more care may be taken when co-administered in the clinic.

Clinical significance of the series of CYP2C9*non3 variants, an unignorable predictor of warfarin sensitivity in Chinese population.

Backgrounds: Gene polymorphisms are critical for variations in warfarin dose. To date, more than 70 CYP2C9 alleles have been identified. This study was designed to clarify the clinical significance of CYP2C9*non-3 variants to warfarin sensitivity in Chinese Han patients. Methods: The entire CYP2C9 gene region was sequenced in 1,993 individuals, and clinical data and VKORC1 genotypes were collected from 986 patients with atrial fibrillation treated with warfarin. The SKAT-O method was used to analyze the effects of CYP2C9*non-3 variants on warfarin sensitivity. Results: A total of 20 CYP2C9 variants were identified, of which four were novel. Carriers with CYP2C9*non-3 variants may have lower warfarin dose requirements, and similar to CYP2C9*3, CYP2C9*non-3 variants are clearly relevant to warfarin-sensitive and highly sensitive responders. Conclusion: Our results showed that, besides CYP2C9*3, the series of CYP2C9*non-3 variants is an unignorable predictor for warfarin sensitivity in Chinese population. From a safety consideration, people carried such variants may need a preferred choice of NOACs when they started anticoagulation therapy.

Identification and drug metabolic characterization of four new CYP2C9 variants CYP2C9*72-*75 in the Chinese Han population.

Cytochrome 2C9 (CYP2C9), one of the most important drug metabolic enzymes in the human hepatic P450 superfamily, is required for the metabolism of 15% of clinical drugs. Similar to other CYP2C family members, CYP2C9 gene has a high genetic polymorphism which can cause significant racial and inter-individual differences in drug metabolic activity. To better understand the genetic distribution pattern of CYP2C9 in the Chinese Han population, 931 individuals were recruited and used for the genotyping in this study. As a result, seven synonymous and 14 non-synonymous variations were identified, of which 4 missense variants were designated as new alleles CYP2C9*72, *73, *74 and *75, resulting in the amino acid substitutions of A149V, R150C, Q214H and N418T, respectively. When expressed in insect cell microsomes, all four variants exhibited comparable protein expression levels to that of the wild-type CYP2C9 enzyme. However, drug metabolic activity analysis revealed that these variants exhibited significantly decreased catalytic activities toward three CYP2C9 specific probe drugs, as compared with that of the wild-type enzyme. These data indicate that the amino acid substitution in newly designated variants can cause reduced function of the enzyme and its clinical significance still needs further investigation in the future.

Evaluation of commonly used cardiovascular drugs in inhibiting vonoprazan metabolism in vitro and in vivo.

As a novel acid-suppressing drug, vonoprazan shows the potential to replace traditional proton-pump inhibitors. With its widespread use, some adverse effects that require further study have emerged due to drug-drug interactions. Our study is the first experiment that evaluated the drug-drug interactions of eleven common cardiovascular drugs that inhibit vonoprazan metabolism in vitro and in vivo. Rat liver microsome incubation and molecular simulation docking were applied to explore the inhibition mechanism. Amlodipine and nifedipine showed inhibitory effects on vonoprazan metabolism in both rat and human liver microsomes in the first evaluation part in vitro. The inhibition mechanism analysis results demonstrated that amlodipine and nifedipine might inhibit the metabolism of vonoprazan by a mixed type of competitive and non-competitive inhibition. However, the pharmacokinetic data of the vonoprazan prototype revealed that amlodipine affected vonoprazan in vivo while nifedipine did not. Thus, more attention should be paid when amlodipine is prescribed with vonoprazan. Furthermore, the changes in its carboxylic acid metabolites MI hinted at a complex situation. Molecular simulation suggested the CYP2B6 enzyme may contribute more to this than CYP3A4, and further inhibitory experiments preliminarily verified this speculation. In conclusion, the use of vonoprazan with cardiovascular drugs, especially amlodipine, should receive particular attention in clinical prescriptions.

MTH1 suppression enhances the stemness of MCF7 through upregulation of STAT3.

MTH1 protein can sanitize the damaged (d)NTP pool and MTH1 inhibitors have been developed to impede the growth of rapidly proliferating tumor cells; however, the effect of MTH1 inhibition on breast cancer stemness has not been reported yet. Here, we constructed breast cancer cell lines with the stable depletion of MTH1. MTH1 suppression clearly increased the ratio of CD44+CD24-/low subpopulations and promoted the formation of tumorspheres in MCF7 and T47D cells. RNA expression profiling, RT-qPCR and Western blotting showed the upregulation of master stem cell transcription factors Sox2, Oct4 and Nanog in MTH1 knockdown cells. GSEA suggested and Western blotting verified that MTH1 knockdown increased the expression of phosphorylated STAT3 (Tyr705). Furthermore, we indirectly demonstrated that the increased concentration of 8-oxo-dGTP and 8-oxo-GTP in MTH1-knockdown cells and exogenous 8-oxoGTP, rather than 8-oxo-dGTP, could significantly increase the phosphorylation of STAT3. In conclusion, this work indicates that MTH1 inhibition increased the proportion of breast cancer stem cells (BCSCs) and promoted stemness properties in MCF7 cells.

Effects of Simvastatin on the Metabolism of Vonoprazan in Rats Both in vitro and in vivo.

Purpose: To study the potential drug-drug interactions between simvastatin and vonoprazan and to provide the scientific basis for rational use of them in clinical practice. Methods: An incubation system was established with rat liver microsomes, and the main metabolite of vonoprazan M-I was detected by UPLC-MS/MS. The IC50 value of simvastatin was then calculated and its inhibitory mechanism against vonoprazan was also analyzed. Twelve SD rats were randomly divided into 2 groups, then they were given simvastatin or saline for 2 weeks continuously. On the day of the experiment, both groups were intragastrically administered with vonoprazan once, followed by the collection of blood at different time points. Then the plasma concentration of vonoprazan and M-I in rats were detected by UPLC-MS/MS. Results: In vitro experiments revealed that simvastatin could inhibit the metabolism of vonoprazan, and its inhibition type belonged to the mixed non-competitive and competitive inhibition model. In vivo experiments in rats demonstrated that the area under concentration time curve (AUC) of vonoprazan was decreased but the clearance (CLz/F) of it was increased in the simvastatin administrated group, as compared to those of the control group. However, M-I in simvastatin treated group exhibited the higher AUC and lower CLz/F values compared to those in the control group. These data indicated that multiple doses of simvastatin administration could reduce the plasma concentration of vonoprazan and accelerate its metabolic rate in rats. Conclusion: Simvastatin could inhibit the metabolism of vonoprazan in vitro but multiple doses of simvastatin exhibited the opposite effect In vivo. Altogether, our data indicated that an interaction existed between simvastatin and vonoprazan and additional cares might be taken when they were co-administrated in clinic.

The GR-gp78 Pathway is involved in Hepatic Lipid Accumulation Induced by Overexpression of 11ß-HSD1.

Glucocorticoids are essential participants in the regulation of lipid metabolism. On a tissue-specific level, glucocorticoid signal is controlled by 11ß-Hydroxysteroid dehydrogenase 1 (11ß-HSD1). Up-regulation of 11ß-HSD1 expression during non-alcoholic fatty liver disease (NAFLD) has been previously shown, while 11ß-HSD1 inhibition has been shown to reduce hepatic lipids in NAFLD, but the underlying mechanisms remain unclear. Here, in this study, we created in vitro cell culture and in vivo transgenic hepatocyte-specific 11ß-HSD1 mouse models of NAFLD to determine the regulatory mechanisms of 11ß-HSD1 during lipid metabolism dysfunction. We found that 11ß-HSD1 overexpression activated glucocorticoid receptors and promoted their nuclear translocation, and then stimulating gp78. The induction of gp78 sharply reduced expression of Insig2, but not Insig1, which led to up-regulation of lipogenesis regulatory proteins including SREBP1, FAS, SCD1, and ACC1. Our results suggested that overexpression of 11ß-HSD1 induced lipid accumulation, at least partially through the GR/gp78/Insig2/SREBP1 pathway, which may serve as a potential diagnostic and therapeutic target for treatment of NAFLD.

Polymorphic mutations in the polb gene promoter and their impact on transcriptional activity.

BACKGROUND: DNA polymerase ß is one of the key enzymes involved in DNA damage repair and its proper expression is strictly controlled within different cells. We previously reported that three genetic mutations in the promoter region of the polb gene are prevalent in the Chinese Han population and two types of mutation are associated with thymic hyperplasia. The purpose of this study was to explore whether other mutated sites exist within the promoter region of the polb gene. METHODS: Genomic DNAs of 421 healthy Chinese Han individuals were extracted from whole blood samples and used for gene amplification of the promoter region of the polb gene. After gel purification, PCR amplicons were sequenced by the Sanger sequencing method and used for sequence alignment with the Lasergene program. PCR products with novel mutations were then subcloned into luciferase reporter plasmid pGL4.10 and transfected into 293T cells for dual-luciferase activity analysis. RESULTS: In total, 11 mutated sites were detected in the Chinese Han population and eight of these were reported for the first time. Using a dual luciferase reporter system, it was found that one novel mutation -142 C > G could decrease the transcription activity of the polb gene, whereas two novel mutations, -152_-151insC and -218 C > G, could significantly increase the transcription activity of the polb gene. CONCLUSIONS: High polymorphic sites could be found in the promoter region of polb gene and approximately half of them could influence its transcription activity.

Effects of dacomitinib on the pharmacokinetics of poziotinib in vivo and in vitro.

CONTEXT: Dacomitinib and poziotinib, irreversible ErbB family blockers, are often used for treatment of non-small cell lung cancer (NSCLC) in the clinic. OBJECTIVE: This study investigates the effect of dacomitinib on the pharmacokinetics of poziotinib in rats. MATERIALS AND METHODS: Twelve Sprague-Dawley rats were randomly divided into two groups: the test group (20 mg/kg dacomitinib for 14 consecutive days) and the control group (equal amounts of vehicle). Each group was given an oral dose of 10 mg/kg poziotinib 30 min after administration of dacomitinib or vehicle at the end of the 14 day administration. The concentration of poziotinib in plasma was quantified by UPLC-MS/MS. Both in vitro effects of dacomitinib on poziotinib and the mechanism of the observed inhibition were studied in rat liver microsomes and human liver microsomes. RESULTS: When orally administered, dacomitinib increased the AUC, Tmax and decreased CL of poziotinib (p < 0.05). The IC50 values of M1 in RLM, HLM and CYP3A4 were 11.36, 30.49 and 19.57 µM, respectively. The IC50 values of M2 in RLM, HLM and CYP2D6 were 43.69, 0.34 and 0.11 µM, respectively, and dacomitinib inhibited poziotinib by a mixed way in CYP3A4 and CYP2D6. The results of the in vivo experiments were consistent with those of the in vitro experiments. CONCLUSIONS: This research demonstrates that a drug-drug interaction between poziotinib and dacomitinib possibly exists when readministered with poziotinib; thus, clinicians should pay attention to the resulting changes in pharmacokinetic parameters and accordingly, adjust the dose of poziotinib in clinical settings.