Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
49 result(s) for "CYP3A7 protein"
Sort by:
Genome-wide Association Study of Estradiol Levels and the Causal Effect of Estradiol on Bone Mineral Density
Abstract Context Estradiol is the primary female sex hormone and plays an important role for skeletal health in both sexes. Several enzymes are involved in estradiol metabolism, but few genome-wide association studies (GWAS) have been performed to characterize the genetic contribution to variation in estrogen levels. Objective Identify genetic loci affecting estradiol levels and estimate causal effect of estradiol on bone mineral density (BMD). Design We performed GWAS for estradiol in males (n = 147 690) and females (n = 163 985) from UK Biobank. Estradiol was analyzed as a binary phenotype above/below detection limit (175 pmol/L). We further estimated the causal effect of estradiol on BMD using Mendelian randomization. Results We identified 14 independent loci associated (P < 5 × 10−8) with estradiol levels in males, of which 1 (CYP3A7) was genome-wide and 7 nominally (P < 0.05) significant in females. In addition, 1 female-specific locus was identified. Most loci contain functionally relevant genes that have not been discussed in relation to estradiol levels in previous GWAS (eg, SRD5A2, which encodes a steroid 5-alpha reductase that is involved in processing androgens, and UGT3A1 and UGT2B7, which encode enzymes likely to be involved in estradiol elimination). The allele that tags the O blood group at the ABO locus was associated with higher estradiol levels. We identified a causal effect of high estradiol levels on increased BMD in both males (P = 1.58 × 10−11) and females (P = 7.48 × 10−6). Conclusion Our findings further support the importance of the body’s own estrogen to maintain skeletal health in males and in females.
Identification of Selective CYP3A7 and CYP3A4 Substrates and Inhibitors Using a High-Throughput Screening Platform
Cytochrome P450 (CYP) 3A7 is one of the major xenobiotic metabolizing enzymes in human embryonic, fetal, and newborn liver. CYP3A7 expression has also been observed in a subset of the adult population, including pregnant women, as well as in various cancer patients. The characterization of CYP3A7 is not as extensive as other CYPs, and health authorities have yet to provide guidance towards DDI assessment. To identify potential CYP3A7-specific molecules, we used a P450-Glo CYP3A7 enzyme assay to screen a library of ∼5,000 compounds, including FDA-approved drugs and drug-like molecules, and compared these screening data with that from a P450-Glo CYP3A4 assay. Additionally, a subset of 1,000 randomly selected compounds were tested in a metabolic stability assay. By combining the data from the qHTS P450-Glo and metabolic stability assays, we identified several chemical features important for CYP3A7 selectivity. Halometasone was chosen for further evaluation as a potential CYP3A7-selective inhibitor using molecular docking. From the metabolic stability assay, we identified twenty-two CYP3A7-selective substrates over CYP3A4 in supersome setting. Our data shows that CYP3A7 has ligand promiscuity, much like CYP3A4. Furthermore, we have established a large, high-quality dataset that can be used in predictive modeling for future drug metabolism and interaction studies.
The Role of CYP3A in Health and Disease
CYP3A is an enzyme subfamily in the cytochrome P450 (CYP) superfamily and includes isoforms CYP3A4, CYP3A5, CYP3A7, and CYP3A43. CYP3A enzymes are indiscriminate toward substrates and are unique in that these enzymes metabolize both endogenous compounds and diverse xenobiotics (including drugs); almost the only common characteristic of these compounds is lipophilicity and a relatively large molecular weight. CYP3A enzymes are widely expressed in human organs and tissues, and consequences of these enzymes’ activities play a major role both in normal regulation of physiological levels of endogenous compounds and in various pathological conditions. This review addresses these aspects of regulation of CYP3A enzymes under physiological conditions and their involvement in the initiation and progression of diseases.
Unveiling dynamic hepatocyte plasticity in HepaRG cells with a dual CYP reporter system
Primary hepatocytes are widely utilized for investigating drug efficacy and toxicity, yet variations between batches and limited proliferation capacity present significant challenges. HepaRG cells are versatile cells, capable of maintaining an undifferentiated state and differentiating through dimethyl sulfoxide treatment, allowing for molecular analysis of hepatocyte plasticity. To elucidate the underlying molecular mechanisms of HepaRG cell plasticity, we used CYP3A4G/7R HepaRG cells engineered to express DsRed under the control of the fetus-specific CYP3A7 gene and EGFP under the adult-specific CYP3A4 gene promoter. In time-lapse imaging of CYP3A4G/7R HepaRG cells, we observed CYP3A7-DsRed expression transitioning from negative to positive during proliferation period and CYP3A4-GFP expression activating during differentiation. The de-differentiation potency of differentiated CYP3A4G/7R HepaRG cells was assessed using inhibitors and cytokines. It was found that Y-27632 (Y), A-83-01 (A), and CHIR99021 (C) (collectively referred to as YAC), which are known to promote liver regeneration in mice, did not induce CYP3A7-DsRed expression. Instead, these inhibitors increased CYP3A4-GFP expressing population. Furthermore, CHIR99021 alone increased CYP3A4-GFP-positive cells, while Wnt3a treatment increased CYP3A7-DsRed-positive cells, suggesting that Wnt signaling plays distinct roles in HepaRG cells. It was apparent that de-differentiated cells had increased CYP3A4 activity after a second round of differentiation, compared to differentiated cells after the first round. Transcriptomic analysis of HepaRG cells revealed distinct profiles between proliferative, differentiated, and de-differentiated states, highlighting their robust plasticity. Notably, hepatoblastic cells de-differentiated by YAC or C displayed transcriptome patterns similar to undifferentiated cells, whereas CYP3A7-DsRed and CYP3A4-GFP exhibited expression patterns different from those of undifferentiated cells. These findings underscore the dynamic nature of HepaRG cells while cautioning against solely relying on CYP3 family gene expression as a marker of differentiation.
The promotion of liver vitamin metabolism is of great significance for laying hens during fasting
Background Induced molt is an effective measure to reduce the introduction cost, cope with the continuous rise of feed cost, and realize the prolonged rearing of laying hens as well. Vitamins are beneficial to the antioxidant capacity and reproductive performance of laying hens, however, studies on vitamin metabolism during fasting are rarely reported. Results We analyzed the association between cecal metabolome and liver transcriptome of laying hens during molt. The results showed that 3009 differences genes (FDR < 0.05), among which there were 62 differential genes related to vitamin metabolism. Eight core genes (ALDH1A1, CYP1A1, CYP1A4, AOX2P, AOX1, CYP3A7, BCAT1, CYP26B1) were obtained by protein network interaction (PPI). These genes were mainly enriched in Metabolic pathways, Retinol metabolism, Folate biosynthesis, One carbon pool by Folate, and Chemical carcinogenesis. After association analysis between these genes and cecal metabolites, a total of 176 differential metabolites were obtained. Among them, the metabolites with higher connectivity were Bifemelane, L-valine, Butyryl Fentanyl-D5 and Rimcazole. Conclusion During fasting, vitamin A and vitamin E stored in the liver of laying hens are released in large quantities with the oxidative decomposition of lipids in the liver during fasting, which accelerates the metabolism of vitamin A in the liver. Folate and biotin may participate in the physiological remodeling of laying hens through epigenetic regulation. In addition, through association analysis, we constructed a data platform for vitamin metabolism-related pathway genes and cecal metabolites, laying a foundation for future research. However, whether the relationship between gene expression in the liver and metabolites in the cecum is bidirectional or unidirectional is still unclear and needs to be further studied.
Identification of diagnostic and prognostic biomarkers in lung adenocarcinoma through integrated bioinformatics analysis and real time PCR validation
Lung cancer is the third most common cancer in the US with a 5-year survival rate of 17%. Non-small cell lung cancer, especially adenocarcinoma, prevails. Therefore, early detection and biomarker discovery are extremely important. This study uses deep learning to find new biomarkers for lung adenocarcinoma. RNA-Seq data from 522 samples, including 506 lung adenocarcinoma patients and 16 healthy controls, were analyzed. DEGs were identified after strict preprocessing, and deep learning algorithms predicted markers. Functional annotation, pathway, and protein interaction analyses elucidated the biological importance of DEGs. Clinical relevance was assessed by correlation with clinical parameters and survival analysis. External validation was carried out using GDAC and GEO datasets. Blood samples from 30 lung adenocarcinoma patients and 30 healthy people were analyzed by real-time PCR to validate the expression levels of key genes. Among 522 participants(506 cases, 16 controls), the mean age was 62.95 ± 15.71 years. Normalized data showed 3,513 DEGs. The deep learning model had a predictive accuracy of 98.44%, Brier score (probability MSE) = 0.0013, and AUC of 1.0. CYP3A7 had the highest effect size. ROC analysis found diagnostic genes A2M, CYP2C9, and SIRPD (Ensembl ID: 128646) with a sensitivity of 0.96. Real-time PCR showed upregulated CYP2C9, KRT14, and PECAM1 and downregulated A2M in patients compared to controls( P  < 0.001). Bioinformatics-identified genes are potential markers for early lung adenocarcinoma detection and management. RT-PCR validation shows AI’s effectiveness in identifying biomarkers, enabling prompt treatment to halt disease progression.
Pregnancy related hormones increase CYP3A mediated buprenorphine metabolism in human hepatocytes: a comparison to CYP3A substrates nifedipine and midazolam
Introduction: Pregnancy increases the clearance of CYP3A4 substrate drugs and pregnancy-related hormones (PRHs) induce hepatic CYP3A4 expression and metabolism. However, it remains unclear to what extent the magnitude of PRH-evoked changes in hepatic CYP3A metabolism varies across multiple substrates. This study quantified the impact of PRHs on CYP3A protein concentrations and buprenorphine metabolism in human hepatocytes, and compared the magnitude of these effects to nifedipine and midazolam metabolism. Methods: Sandwich-cultured human hepatocytes (SCHH) from female donors were exposed to PRHs, administered in combination across a range of physiologically relevant concentrations, for 72 h. Absolute protein concentrations of CYP3A4, CYP3A5, and CYP3A7 in SCHH membrane fractions were quantified by nanoLC-MS/MS, and norbuprenorphine (nor-BUP), dehydro-nifedipine (dehydro-NIF), and 1-hydroxy-midazolam (1-OH-MDZ) formation was evaluated. Results: Compared to control, PRH exposure increased CYP3A4, CYP3A7, and total CYP3A protein concentrations, but not CYP3A5 concentrations, and increased nor-BUP, dehydro-NIF, and 1-OH-MDZ formation in a concentration-dependent manner. The formation of nor-BUP, dehydro-NIF, and 1-OH-MDZ each positively correlated with PRH-mediated changes in total CYP3A protein concentrations. The PRH-evoked increase in nor-BUP formation was evident in all donors; however, the PRH induction of dehydro-NIF and 1-OH-MDZ formation was diminished in a hepatocyte donor with high basal CYP3A5 expression. Discussion: These findings demonstrate that PRHs increase buprenorphine, nifedipine, and midazolam metabolism in SCHH via induction of CYP3A4 and total CYP3A protein concentrations, and the magnitude of these effects vary across hepatocyte donors in a substrate-specific manner. These data provide insight into the contribution of PRH induction of CYP3A4 metabolism to increased buprenorphine clearance during pregnancy.
Toxicogenomics directory of chemically exposed human hepatocytes
A long-term goal of numerous research projects is to identify biomarkers for in vitro systems predicting toxicity in vivo. Often, transcriptomics data are used to identify candidates for further evaluation. However, a systematic directory summarizing key features of chemically influenced genes in human hepatocytes is not yet available. To bridge this gap, we used the Open TG-GATES database with Affymetrix files of cultivated human hepatocytes incubated with chemicals, further sets of gene array data with hepatocytes from human donors generated in this study, and publicly available genome-wide datasets of human liver tissue from patients with non-alcoholic steatohepatitis (NASH), cirrhosis, and hepatocellular cancer (HCC). After a curation procedure, expression data of 143 chemicals were included into a comprehensive biostatistical analysis. The results are summarized in the publicly available toxicotranscriptomics directory ( http://wiki.toxbank.net/toxicogenomics-map/ ) which provides information for all genes whether they are up- or downregulated by chemicals and, if yes, by which compounds. The directory also informs about the following key features of chemically influenced genes: (1) Stereotypical stress response. When chemicals induce strong expression alterations, this usually includes a complex but highly reproducible pattern named ‘stereotypical response.’ On the other hand, more specific expression responses exist that are induced only by individual compounds or small numbers of compounds. The directory differentiates if the gene is part of the stereotypical stress response or if it represents a more specific reaction. (2) Liver disease-associated genes. Approximately 20 % of the genes influenced by chemicals are up- or downregulated, also in liver disease. Liver disease genes deregulated in cirrhosis, HCC, and NASH that overlap with genes of the aforementioned stereotypical chemical stress response include CYP3A7, normally expressed in fetal liver; the phase II metabolizing enzyme SULT1C2; ALDH8A1, known to generate the ligand of RXR, one of the master regulators of gene expression in the liver; and several genes involved in normal liver functions: CPS1, PCK1, SLC2A2, CYP8B1, CYP4A11, ABCA8, and ADH4. (3) Unstable baseline genes. The process of isolating and the cultivation of hepatocytes was sufficient to induce some stress leading to alterations in the expression of genes, the so-called unstable baseline genes. (4) Biological function. Although more than 2,000 genes are transcriptionally influenced by chemicals, they can be assigned to a relatively small group of biological functions, including energy and lipid metabolism, inflammation and immune response, protein modification, endogenous and xenobiotic metabolism, cytoskeletal organization, stress response, and DNA repair. In conclusion, the introduced toxicotranscriptomics directory offers a basis for a rationale choice of candidate genes for biomarker evaluation studies and represents an easy to use source of background information on chemically influenced genes.
CYP3A5 and CYP3A7 genetic polymorphisms affect tacrolimus concentration in pediatric patients with nephrotic range proteinuria
Purpose The purpose of this study was to investigate the potential impact of CYP3A4, CYP3A5, and CYP3A7 polymorphisms on the concentration and efficacy of tacrolimus in a cohort of pediatric patients with nephrotic range proteinuria. Methods Genetic variants including CYP3A5*3 (rs776746), CYP3A4*1G (rs2242480), rs4646437, and CYP3A7 rs2257401 and rs10211 were detected in 70 pediatric patients with nephrotic range proteinuria. The relationships of dose-adjusted trough concentration ( C 0 ) of tacrolimus with corresponding genotypes were investigated. Results The tacrolimus concentration in patients without CYP3A5*3 A allele was 94% higher than those with A allele (90.7 vs 54.2, P  = 0.00006). The CYP3A7 rs2257401 was also associated with the concentration of tacrolimus. The C allele carriers had an obviously lower C 0 than the non-carriers (62.4 vs 90.7, P  = 0.001). In addition, there were significant differences in tacrolimus concentration among CYP3A7 rs10211 G carriers and non-carriers; the latter had an almost twofold C 0 of the former (101.8 vs 59.6, P  = 0.0004). Conclusions Our study demonstrated the associations between CYP3A5*3, CYP3A7 rs2257401 and rs10211, and tacrolimus concentration in pediatric patients with nephrotic range proteinuria. Children with CYP3A5*3 A, CYP3A7 rs2257401 C, and rs10211 G alleles might need a higher dose of tacrolimus.
Endosulfan exposure alters transcription of genes involved in the detoxification and stress responses in Physella acuta
Endosulfan is a persistent pesticide that has been in use for more than five decades. During this time, it has contaminated soil, air, and water reservoirs worldwide. It is extremely toxic and harmful to beneficial non-target invertebrates, aquatic life, and even humans upon consumption, which is one of the many dangers of this pesticide since it biomagnifies in the food chain. The effects of three endosulfan concentrations (1, 10, and 100 µg/L) on the freshwater snail Physella acuta , an invasive cosmopolitan species, were examined over a week-long exposure period. Alterations in the expression of ten genes related to stress and xenobiotic detoxification were measured against the endogenous controls rpL10 and GAPDH by Real-Time polymerase chain reaction. Four genes are described here for the first time in this species, namely Hsp60 , Grp78 , GSTk1 , and GSTm1 . The rest of genes were Hsp90 , sHsp16.6 , cyp2u1 , cyp3a7 , cyp4f22 , and MRP1 . cyp2u1 , sHsp16.6 , and Grp78 expression were all altered by endosulfan. These results suggest a low pesticide concentration activates the acute response in P. acuta by affecting detoxification and stress responses and alter endoplasmic reticulum function and lipid metabolism. Furthermore, the newly identified genes extend the number of processes and cellular locations that can be analyzed in this organism.