Cytochrome P450 Subfamily Research Articles

25-Hydroxyvitamin D status is associated with interleukin-6 methylation in adipose tissue from patients with colorectal cancer.

A dysfunctional visceral adipose tissue (VAT) is characterized by increased production of proinflammatory cytokines, which may increase the risk of colorectal cancer (CRC). However, the epigenetic contribution to the inflammatory status is poorly understood. In our study, we hypothesized that a dysfunctional VAT may be a risk factor for CRC, through epigenetic modifications. Therefore, we aimed to study the transcriptional/methylation profile of proinflammatory cytokines and genes related to vitamin D metabolism in VAT from CRC patients, and evaluate their association with serum 25-hydroxyvitamin D (25(OH)D). We included 129 participants (68 healthy participants and 61 CRC patients). We found that the majority of the studied genes are upregulated and hypomethylated in CRC patients, when compared to the healthy subjects (p < 0.05). In addition, serum 25(OH)D was associated with both mRNA gene expression and methylation of key genes, such as interleukin (IL)6, IL10, vitamin D receptor (VDR) or cytochrome P450 subfamily 27 type B1 (CYP27B1) (p < 0.05). Interestingly, while high IL6 expression was related to poor survival in CRC (p < 0.05), IL6 methylation was associated with an increased risk of CRC, in which 25(OH)D partially mediated this association (p < 0.05). Our study suggests a potential association between epigenetic regulation of inflammatory mediators in VAT - such as IL6 - in the CRC context, in which 25(OH)D may mediate this risk. Therefore, vitamin D could affect the epigenetic status of IL6, which can be considered for additional preventive strategies.

Comparative transcriptomics indicates endogenous differences in detoxification capacity after formic acid treatment between honey bees and varroa mites

Formic acid (FA) has been used for decades to control Varroa destructor, one of the most important parasites of the western honey bee, Apis mellifera. The rather unselective molecular mode of action of FA and its possible effects on honeybees have long been a concern of beekeepers, as it has undesirable side effects that affect the health of bee colonies. This study focuses on short-term transcriptomic changes as analysed by RNAseq in both larval and adult honey bees and in mites after FA treatment under applied conditions. Our study aims to identify those genes in honey bees and varroa mites differentially expressed upon a typical FA hive exposure scenario. Five detoxification-related genes were identified with significantly enhanced and one gene with significantly decreased expression under FA exposure. Regulated genes in our test setting included members of various cytochrome P450 subfamilies, a flavin-dependent monooxygenase and a cytosolic 10-formyltetrahydrofolate dehydrogenase (FDH), known to be involved in formate metabolism in mammals. We were able to detect differences in the regulation of detoxification-associated genes between mites and honey bees as well as between the two different developmental stages of the honey bee. Additionally, we detected repressed regulation of Varroa genes involved in cellular respiration, suggesting mitochondrial dysfunction and supporting the current view on the mode of action of FA—inhibition of oxidative phosphorylation. This study shows distinct cellular effects induced by FA on the global transcriptome of both host and parasite in comparison. Our expression data might help to identify possible differences in the affected metabolic pathways and thus make a first contribution to elucidate the mode of detoxification of FA.

Cytochrome P450-mediated mycotoxin metabolism by plant-feeding insects.

Mycotoxins are secondary metabolites produced primarily by filamentous fungi that when consumed cause pathological responses in animal hosts or consumers. Defined functionally rather than structurally, mycotoxins derive from numerous primary metabolic pathways. Through opportunistic or mutualistic associations, insect herbivores inflict damage that can predispose plants to infection by mycotoxin-producing phytopathogens, resulting in economically significant contamination. The few cytochrome P450 subfamilies implicated in mycotoxin detoxification by insects, including CYP6 and CYP9, are also known to detoxify phytochemicals. Some insect P450s bioactivate, rather than detoxify, mycotoxins, suggestive of an 'escalation' in arms-race interactions between these herbivores and fungi. Characterizing insect P450s that detoxify mycotoxins can be useful for developing biological remediation technologies and for ensuring the safety of insects reared for human or livestock consumption.

Hsa-miR-4271 downregulates the expression of constitutive androstane receptor and enhances in vivo the sensitivity of non-small cell lung cancer to gefitinib

The efficacy of molecular targeting agents is dependent on the metabolism or nuclear receptor-mediated clearance of chemotherapy resistance-related factors such as cytochrome P450 (CYP) or ATP binding cassette subfamily B member 1 (ABCB1). In this study, we revealed the roles of the microRNA-4271/CAR (constitutive androstane receptor) axis in the regulation of the resistance to molecular anticancer targeting agents in non-small cell lung cancer (NSCLC) cells including two main categories of NSCLC: lung adenocarcinoma (AC) and large cell lung cancer (LCC). The expression of miR-4271 was negatively correlated with CAR expression in NSCLC tissues. MiR-4271 targeted CAR and inhibited the activation of the CAR signaling pathway. Overexpression of CAR in NSCLC enhanced the resistance of NSCLC cells to molecular targeting agents and miR-4271-infected NSCLC cells enhanced their sensitivity to molecular targeting agents such as Gefitinib. The mechanism-data showed that overexpression of miR-4271 decelerated the mechanism or the clearance of molecular targeting agents by targeting the 3′UTR (3′ un-translation region). These results suggest that miR-4271 may contribute to the development of more effective strategies for the treatment of advanced NSCLC.

Both LmCYP4G genes function in decreasing cuticular penetration of insecticides in Locusta migratoria.

Cuticular hydrocarbons (CHCs) have a critical role in preventing desiccation and penetration of xenobiotics in insects. Previous studies have shown that cytochrome P450 subfamily 4G (CYP4G) enzymes are oxidative decarbonylases, essential for CHC biosynthesis. However, it is unclear whether there are functional differences between the two CYP4G genes in most insects. In Locusta migratoria, we identified two CYP4G genes (LmCYP4G62 and LmCYP4G102). LmCYP4G102 plays a critical role in the synthesis of CHCs, but the function of LmCYP4G62 is unknown. We identified, characterized, and compared two LmCYP4G genes, based on L. migratoria transcriptomic and genomic databases. RT-qPCR showed that both were highly expressed in tissues with which oenocytes are associated, the integument and fat body. Immunostaining indicated that LmCYP4G62 and LmCYP4G102 were highly abundant in oenocytes in these tissues. However, the two enzymes had a different subcellular distribution, with LmCYP4G62 localized on the plasma membrane and LmCYP4G102 dispersed throughout the oenocyte cytoplasm, presumably on the endoplasmic reticulum. RNA interference-mediated gene silencing against each of the two genes resulted in reduced CHC contents, in all classes for LmCYP4G102, but mostly shorter chain CHCs for LmCYP4G62. Silencing of both genes resulted in increased insecticide penetration through the cuticle, and increased locust susceptibility to desiccation and insecticides. Our studies suggest that both LmCYP4G62 and LmCYP4G102 contribute to hydrocarbon biosynthesis and play key roles in protecting locusts from water loss and insecticide penetration, but they are not fully redundant. Further, the two LmCYP4G genes might be used as new targets for insect pest management. © 2020 Society of Chemical Industry.

The effects of aripiprazole and olanzapine on pupillary light reflex and its relationship with pharmacogenetics in a randomized multiple-dose trial.

AimsPupillography is a noninvasive and cost‐effective method to determine autonomic nerve activity. Genetic variants in cytochrome P450 (CYP), dopamine receptor (DRD2, DRD3), serotonin receptor (HTR2A, HTR2C) and ATP‐binding cassette subfamily B (ABCB1) genes, among others, were previously associated with the pharmacokinetics and pharmacodynamics of antipsychotic drugs. Our aim was to evaluate the effects of aripiprazole and olanzapine on pupillary light reflex related to pharmacogenetics.MethodsTwenty‐four healthy volunteers receiving 5 oral doses of 10 mg aripiprazole and 5 mg olanzapine tablets were genotyped for 46 polymorphisms by quantitative polymerase chain reaction. Pupil examination was performed by automated pupillometry. Aripiprazole, dehydro‐aripiprazole and olanzapine plasma concentrations were measured by high‐performance liquid chromatography–tandem mass spectrometry.ResultsAripiprazole affected pupil contraction: it caused dilatation after the administration of the first dose, then caused constriction after each dosing. It induced changes in all pupillometric parameters (P < .05). Olanzapine only altered minimum pupil size (P = .046). Polymorphisms in CYP3A, HTR2A, UGT1A1, DRD2 and ABCB1 affected pupil size, the time of onset of constriction, pupil recovery and constriction velocity. Aripiprazole, dehydro‐aripiprazole and olanzapine pharmacokinetics were significantly affected by polymorphisms in CYP2D6, CYP3A, CYP1A2, ABCB1 and UGT1A1 genes.ConclusionsIn conclusion, aripiprazole and its main metabolite, dehydro‐aripiprazole altered pupil contraction, but olanzapine did not have such an effect. Many polymorphisms may influence pupillometric parameters and several polymorphisms had an effect on aripiprazole, dehydro‐aripiprazole and olanzapine pharmacokinetics. Pupillography could be a useful tool for the determination of autonomic nerve activity during antipsychotic treatment.

CYP722C from Gossypium arboreum catalyzes the conversion of carlactonoic acid to 5-deoxystrigol.

CYP722C from cotton, a homolog of the enzyme involved in orobanchol synthesis in cowpea and tomato, catalyzes the conversion of carlactonoic acid to 5-deoxystrigol. Strigolactones (SLs) are important phytohormones with roles in the regulation of plant growth and development. These compounds also function as signaling molecules in the rhizosphere by interacting with beneficial arbuscular mycorrhizal fungi and harmful root parasitic plants. Canonical SLs, such as 5-deoxystrigol (5DS), consist of a tricyclic lactone ring (ABC-ring) connected to a methylbutenolide (D-ring). Although it is known that 5DS biosynthesis begins with carlactonoic acid (CLA) derived from β-carotene, the enzyme that catalyzes the conversion of CLA remains elusive. Recently, we identified cytochrome P450 (CYP) CYP722C as the enzyme that catalyzes direct conversion of CLA to orobanchol in cowpea and tomato (Wakabayashi et al., Sci Adv 5:eaax9067, 2019). Orobanchol has a different C-ring configuration from that of 5DS. The present study aimed to characterize the homologous gene, designated GaCYP722C, from cotton (Gossypium arboreum) to examine whether this gene is involved in 5DS biosynthesis. Expression of GaCYP722C was upregulated under phosphate starvation, which is an SL-producing condition. Recombinant GaCYP722C was expressed in a baculovirus-insect cell expression system and was found to catalyze the conversion of CLA to 5DS but not to 4-deoxyorobanchol. These results strongly suggest that GaCYP722C from cotton is a 5DS synthase and that CYP722C is the crucial CYP subfamily involved in the generation of canonical SLs, irrespective of the different C-ring configurations.

Regulating Retinoic Acid Availability during Development and Regeneration: The Role of the CYP26 Enzymes.

This review focuses on the role of the Cytochrome p450 subfamily 26 (CYP26) retinoic acid (RA) degrading enzymes during development and regeneration. Cyp26 enzymes, along with retinoic acid synthesising enzymes, are absolutely required for RA homeostasis in these processes by regulating availability of RA for receptor binding and signalling. Cyp26 enzymes are necessary to generate RA gradients and to protect specific tissues from RA signalling. Disruption of RA homeostasis leads to a wide variety of embryonic defects affecting many tissues. Here, the function of CYP26 enzymes is discussed in the context of the RA signalling pathway, enzymatic structure and biochemistry, human genetic disease, and function in development and regeneration as elucidated from animal model studies.

The Cytochrome P450 Monooxygenase Inventory of Grapevine (Vitis vinifera L.): Genome-Wide Identification, Evolutionary Characterization and Expression Analysis.

The cytochrome P450 (CYP) monooxygenase superfamily, belonging to heme-thiolate protein products, plays a vital role in metabolizing physiologically valuable compounds in plants. To date, CYP superfamily genes have not yet been characterized in grapevine (V. vinifera L.), and their functions remain unclear. In this study, a sum of 236 VvCYPs, divided into 46 families and clustered into nine clans, have been identified based on bioinformatics analyses in grapevine genome. The characteristics of both exon–intron organizations and motif structures further supported the close evolutionary relationships of VvCYP superfamily as well as the reliability of phylogenetic analysis. The gene number-based hierarchical cluster of CYP subfamilies of different plants demonstrated that the loss of CYP families seems to be limited to single species or single taxa. Promoter analysis elucidated various cis-regulatory elements related to phytohormone signaling, plant growth and development, as well as abiotic/biotic stress responses. The tandem duplication mainly contributed to the expansion of the VvCYP superfamily, followed by singleton duplication in grapevine. Global RNA-sequencing data of grapevine showed functional divergence of VvCYPs as diverse expression patterns of VvCYPs in various organs, tissues, and developmental phases, which were confirmed by quantitative real-time reverse transcription PCR (qRT-PCR). Taken together, our results provided valuable inventory for understanding the classification and biological functions of the VvCYPs and paved the way for further functional verification of these VvCYPs and are helpful to grapevine molecular breeding.

Vitamin D-related genes and cardiometabolic markers in healthy children: a Mendelian randomisation study.

Observational studies show associations between low serum 25-hydroxyvitamin D (25(OH)D) and cardiometabolic risk markers. This Mendelian randomisation study examined associations between cardiometabolic markers in children and SNP in genes related to vitamin D metabolism (DHCR7; group-specific complement (GC); cytochrome P450 subfamily IIR1 (CYP2R1); and CYP24A1) and action (CYP27B1 and VDR). In 699 healthy 8-11-year-old children, we genotyped eleven SNP. We generated a genetic risk score based on SNP associated with low 25(OH)D and investigated associations between this and blood pressure, plasma lipids and insulin. Furthermore, we examined whether SNP related to vitamin D actions modified associations between 25(OH)D and the cardiometabolic markers. All GC and CYP2R1 SNP influenced serum 25(OH)D. A risk score based on four of the six SNP was associated with 3·4 (95 % CI 2·6, 4·2) mmol/l lower 25(OH)D per risk allele (P < 0·001), but was not associated with the cardiometabolic markers. However, interactions were indicated for the three VDR SNP (Pinteraction < 0·081) on associations between 25(OH)D and TAG, systolic blood pressure and insulin, which all decreased with increasing 25(OH)D only in major allele homozygotes (β -0·02 (95 % CI -0·04, -0·01) mmol/l; β -0·5 (95 % CI -0·9, -0·1) mmHg; and β -0·5 (95 % CI -1·4, 0·3) pmol/l, respectively). In conclusion, genetic variation affected 25(OH)D substantially, but the genetic score was not associated with cardiometabolic markers in children. However, VDR polymorphisms modified associations with vitamin D, which warrants further investigation of VDR's role in the relationship between vitamin D and cardiometabolic risk.

Identification of key genes and their functions in palbociclib-resistant breast carcinoma by using bioinformatics analysis

Background: Palbociclib resistance is a significant problem in breast carcinoma, and its underlying molecular mechanisms remain poorly understood. This study aims to elucidate the molecular mechanisms of palbociclib resistance and to identify the key genes and pathways mediating progesterone resistance in breast cancer (BC). Methods: Gene dataset GSE117743 was downloaded from the Gene Expression Omnibus (GEO) database, which included 3 palbociclib-resistant and 3 palbociclib-sensitive BC cell lines. Then, we calculated the differentially expressed genes (DEGs) by using R software. Gene ontology and Enriched pathway analysis of genes we identified were analyzed by using the Database for Database of Annotation Visualization and Integrated Discovery (DAVID) and R software. The protein-protein interaction network was performed according to Metascape, String, and Cytoscape software. Results: In total, 447 DEGs were selected, which consisted of 67 upregulated and 380 downregulated genes. According to gene ontology annotation, DEGs were associated with cytoplasm, signal transduction, and protein binding. The research of the Kyoto Encyclopedia of Genes and Genomes (KEGG) demonstrated that genes enriched in certain tumor pathways, including IL-17 signaling pathways and Herpes simplex infection signaling pathways. Also, certain hub genes were highlighted after constructed and analyzed the protein-protein interaction network, including α-2A adrenergic receptor, cytochrome P450 subfamily IIR polypeptide, Cystathionine β-synthase, nucleotide-binding oligomerization domain-containing, erythropoietin-producing hepatocellular receptor A2 and adrenomedullin, which may be related with BC prognosis. A total of 4 of 6 hub genes had a significant relationship with the overall survival (P&lt;0.05). Conclusions: Using microarray and bioinformatics analyses, we identified DEGs and determined a comprehensive gene network of progesterone resistance. We offered several possible mechanisms of progesterone resistance and identified therapeutic and prognostic targets of palbociclib resistance in BC.

Cloning and Analysis of &amp;lt;i&amp;gt;RrF&amp;lt;/i&amp;gt;3’ H in Rosa rugosa

Rosa rugosa is an important garden ornamental plant which belongs to the genus Rosa of the family Rosaceae. The current wild and cultivated R. rugosa are mostly purple, pink, a small amount of white, but lack of yellow, orange and so on. Flavonoids 3’-hydroxylase belongs to CYP75B subfamily of cytochrome P450, and is an essential enzyme in anthocyanins synthesis. In this experiment, RrF3’H gene was cloned from the petal of Rosa rugosa ‘Hunchun’ using RT-PCR, and bioinformatics analysis was performed. The RrF3’H gene’s full length of opening reading frame was 1687 bp, encoding 510 amino acids. The formulas of proteins encoded by RrF3’H were C2666H4149N699O734S24. The derived protein had a molecular weight of 58,506.95 Da. The aliphatic index was 90.94. It belongs to unstable hydrophilic protein. The protein consists of 46.76% α-helix, 31.04% random coil, 7.66% β-corner and 14.54% extended strand. The protein contains 21 Ser phosphorylation sites, 12 Thr phosphorylation sites, and 2 Tyr phosphorylation sites. The protein contained two O-glycosylation sites, located at positions 98 and 263 of the amino acid sequence respectively. The protein has a signal peptide site and a transmembrane structure. In addition, by comparing the expression levels of RrF3’H, we found RrF3’H was positively correlated with the depth of flower color.

Development of organoid-based drug metabolism model

Cytochrome P450 (CYP) gene superfamily catalyzes oxidative metabolism of a wide variety of drugs, carcinogens, and endogenous biomolecules in the liver and intestinal organs. In vitro assay platforms such as primary hepatocyte and immortalized liver-derived cell lines have been developed to evaluate drug effects. However, several limitations have been suggested regarding discrepancies between in vitro and in vivo assays. In this study, we aimed to investigate drug metabolism and toxicity based on mouse small intestinal and liver organoids derived from resident stem cells. At first, expressions and activities of CYP subfamilies (CYPs) in intestinal and liver organoids were investigated. Organoids treated with three CYPs-inducers dexamethasone (Dex), β-naphthoflavone (BNF), and 1,4-bis-2-(3, 5-dichloropyridyloxy)-benzene (TCPOBOP) were evaluated for CYPs activities. The CYPs-induced intestinal and liver organoids were confirmed to digest more docetaxel, as colon cancer cell-line survived more in CYPs-induced organoid's medium than in non-induced organoid's medium. Then, the activity of docetaxel in a co-culture platform of mouse liver organoids and human pancreatic tumoroids was measured. We obtained significant statistical values on CYPs-induced metabolic activities: cell survival rates of pancreatic tumoroids co-cultured with docetaxel-treated undifferentiated, differentiated, and CYPs-induced differentiated organoids were 66.05 ± 2.14%, 89.20 ± 2.67%, and 101.90 ± 0.94%, respectively. To sum up, gene expression modification and drug metabolism evaluation were able to be done with organoids as done with tissues. In vivo-like in vitro investigation on drug toxicity may potentially be done with organoids as a stepping bridge to the clinical trial.

Protective roles of FICZ and aryl hydrocarbon receptor axis on alveolar bone loss and inflammation in experimental periodontitis.

The aryl hydrocarbon receptor (AhR)-ligand axis has been shown to be involved in inflammatory diseases and bone homeostasis. However, the activation of AhR signalling pathway and the possible functions of AhR ligands in periodontitis are underexplored. This study investigated the expression of the AhR target gene cytochrome P450 subfamily B member 1 (CYP1B1) and the functions and mechanisms of the AhR ligand 6 formylindolo[3,2-b]carbazole (FICZ) in periodontitis. CYP1B1 expression was detected in human periodontitis samples, mice with ligature-induced periodontitis and lipopolysaccharide (LPS)-induced inflammation in periodontal ligament cells (PDLCs) in vitro. FICZ was administered topically or systemically. The therapeutic functions of FICZ were detected via qPCR, micro-computed tomography and immunohistochemistry. Finally, the mechanisms of AhR signalling in periodontitis were investigated by cell assays. CYP1B1 expression was downregulated in periodontitis. FICZ rescued the alveolar bone loss and mitigated the inflammatory cytokines in periodontitis mice. In vitro, FICZ pre-treatment reduced the LPS-induced inflammation in PDLCs via the increased phosphorylation of STAT3. Additionally, FICZ prompted the mineralization of PDLCs via activation of the Wnt/β-catenin signalling pathway. AhR signalling pathway is suppressed in periodontitis and the AhR ligand FICZ can prevent periodontitis.

Current perspectives in Bietti crystalline dystrophy.

Bietti crystalline dystrophy (BCD) is a rare-inherited disease caused by mutations in the CYP4V2 gene and characterized by the presence of multiple shimmering yellow-white deposits in the posterior pole of the retina in association with atrophy of the retinal pigment epithelium (RPE) and chorioretinal atrophy. The additional presence of glittering dots located at the corneal limbus is also a frequent finding. The CYP4V2 protein belongs to the cytochrome P450 subfamily 4 and is mainly expressed in the retina and the RPE and less expressed in the cornea. The disease has its metabolic origin in the diminished transformation of fatty acid substrates into n-3 polyunsaturated fatty acids due to a dysregulation of the lipid metabolism. In this review, we provide updated insights on clinical and molecular characteristics of BCD including underlying mechanisms of BCD, genetic diagnosis, progress in the identification of causative genetic and epigenetic factors, available techniques of exploration and development of novel therapies. This information will help clinicians to improve accuracy of BCD diagnosis, providing the patient reliable information regarding prognosis and clinical prediction of the disease course.

A Plant like Cytochrome P450 Subfamily CYP710C1 Gene in Leishmania donovani Encodes Sterol C-22 Desaturase and its Over-expression Leads to Resistance to Amphotericin B.

BackgroundLeishmania donovani is a protozoan parasite, a primary causative agent of visceral leishmaniasis. Sterol produced via the mevalonate pathway, show differences in composition across biological kingdoms. The specific occurrence of Δ22-unsaturated sterols, containing a double bond at the C-22 position in the side chain occurs in fungi as ergosterol and as stigmasterol in plants. In the present study, we report the identification and functional characterization of a plant-like Cytochrome P450 subfamily CYP710C1 in L. donovani as the Leishmania C-22 desaturase.MethodologyIn silico analysis predicted the presence of a plant like CYP710C1 gene that encodes a sterol C-22 desaturase, a key enzyme in stigmasterol biosynthesis. The enzymatic function of recombinant CYP710C1 as C-22 desaturase was determined. To further study the physiological role of CYP710C1 in Leishmania, we developed and characterized an overexpressing strain and a gene deletion mutant. C-22 desaturase activity and stigmasterol levels were estimated in the wild-type, overexpressing promastigotes and heterozygous mutants.ConclusionWe for the first time report the presence of a CYP710C1 gene that encodes a plant like sterol C-22 desaturase leading to stigmasterol biosynthesis in Leishmania. The recombinant CYP710C1 exhibited C-22 desaturase activity by converting β-sitosterol to stigmasterol. Axenic amastigotes showed higher expression of CYP710C1 mRNA, protein and stigmasterol levels compared to the promastigotes. Sterol profiling of CYP710C1 overexpressing L. donovani and heterozygous mutant parasites demonstrated that CYP710C1 was responsible for stigmasterol production. Most importantly, we demonstrate that these CYP710C1 overexpressing promastigotes are resistant to amphotericin B, a drug of choice for use against leishmaniasis. We report that Leishmania sterol biosynthesis pathway has a chimeric organisation with characteristics of both plant and fungal pathways.

CYP3A drug metabolism in the developmental age: recent advances

Background. The 3A subfamily of cytochrome P450 (CYP3A) accomplishes phase I metabolism for approximately half of the available medications. We aimed to review the recent advances in our understanding of CYP3A activity, which could apply to infants and toddlers.Material and Methods. A literature review.Results. The reviewed recent data cover: CYP3A7 expression and functions, changes of CYP3A4 function in the first two years of life, CYP3A intestinal metabolism and zonation, CYP3A metabolic programming, pediatric CYP3A pharmacogenetics, the impact of critical illness on CYP3A, phenotyping, and other clinical implications of a better comprehension of CYP3A biology.Conclusions. Although the knowledge of CYP3A enzymes has already changed pediatric practice, much more is to be expected in the upcoming years. The areas to watch include: endogenous markers for phenotyping, new CYP3A7 substrates and products, pharmacogenetic interactions with transporter genes for non‑immunomodulatory drugs, as well as interactions with microbiota and specific bioactive foodstuffs.

Non randomized study on the potential of nitisinone to inhibit cytochrome P450 2C9, 2D6, 2E1 and the organic anion transporters OAT1 and OAT3 in healthy volunteers

PurposeNitisinone inhibits the cytochrome P450 (CYP) subfamilies CYP2C9, CYP2D6, and CYP2E1 and the organic anion transporter (OAT) isoforms OAT1 and OAT3 in vitro. Since the effect of nitisinone on these enzymes and transporters in humans is still unknown, the purpose of this study was to evaluate the effect of nitisinone on these CYP subfamilies and OAT isoforms.MethodsThis was an open-label, nonrandomized, two-arm, phase 1 study (EudraCT: 2016-004297-17) in healthy volunteers. The substrates (tolbutamide, metoprolol, and chlorzoxazone for the respective CYPs and furosemide for the OATs) were administered as single doses, before and after 15 days of once daily dosing of 80 mg nitisinone, to determine the AUC∞ ratios ([substrate+nitisinone]/[substrate]). Nitisinone pharmacokinetics, safety, and tolerability were also assessed, and blood and urine were collected to determine substrate and nitisinone concentrations by LC-MS/MS.ResultsThirty-six subjects were enrolled with 18 subjects included in each arm. The least square mean ratio (90% confidence interval) for AUC∞ was 2.31 (2.11–2.53) for tolbutamide, 0.95 (0.88–1.03) for metoprolol, 0.73 (0.67–0.80) for chlorzoxazone, and 1.72 (1.63–1.81) for furosemide. Clinically relevant nitisinone steady-state concentrations were reached after 12 days: mean Cav,ss of 94.08 μM. All treatments were well tolerated, and no safety concerns were identified.ConclusionsNitisinone did not affect CYP2D6 activity, was a weak inducer of CYP2E1, and was a weak inhibitor of OAT1 and OAT3. Nitisinone was a moderate inhibitor of CYP2C9, and treatment may therefore result in increased plasma concentrations of comedications metabolized primarily via this enzyme.Clinical trial registry identificationEudraCT 2016-004297-17.

Prediction of the Ligands of the CYP9e Subfamily of Ant Cytochrome P450 with the ChEBI Ontologies of Chemical and Biological Characteristics

Cytochromes P450 are involved in the metabolism of various endogenous and exogenous compounds, and their role in the detoxification of xenobiotics has been extensively studied. CYP9e, one of the subfamilies of cytochromes P450, whose functions have been poorly studied, is amplified in the black garden ant Lasius niger. We have performed molecular modeling of 23 proteins of this family belonging to L. niger and other ant species, as well as molecular docking and virtual screening of suspected ligands. The substances used as ligands have been annotated with ChEBI ontologies to predict the chemical and biological properties of molecules forming complexes with CYP9e of ants. It has been shown that, among the ligands forming energetically favorable complexes, ChEBI ontologies of mycotoxins, phytotoxins, steroids, glycosides and terpenoids are overrepresented. Nevertheless, it has been demonstrated that in carrying out a large number of inaccurate simulations, the results of function predictions can be correlated with molecular docking and the evolutionary history of a protein family.

Identification and expression analysis of cytokinin metabolic genes IPTs, CYP735A and CKXs in the biofuel plant Jatropha curcas.

The seed oil of Jatropha curcas is considered a potential bioenergy source that could replace fossil fuels. However, the seed yield of Jatropha is low and has yet to be improved. We previously reported that exogenous cytokinin treatment increased the seed yield of Jatropha. Cytokinin levels are directly regulated by isopentenyl transferase (IPT), cytochrome P450 monooxygenase, family 735, subfamily A (CYP735A), and cytokinin oxidase/dehydrogenase (CKX). In this study, we cloned six IPT genes, one JcCYP735A gene, and seven JcCKX genes. The expression patterns of these 14 genes in various organs were determined using real-time quantitative PCR. JcIPT1 was primarily expressed in roots and seeds, JcIPT2 was expressed in roots, apical meristems, and mature leaves, JcIPT3 was expressed in stems and mature leaves, JcIPT5 was expressed in roots and mature leaves, JcIPT6 was expressed in seeds at 10 days after pollination, and JcIPT9 was expressed in mature leaves. JcCYP735A was mainly expressed in roots, flower buds, and seeds. The seven JcCKX genes also showed different expression patterns in different organs of Jatropha. In addition, CK levels were detected in flower buds and seeds at different stages of development. The concentration of N6-(Δ2-isopentenyl)-adenine (iP), iP-riboside, and trans-zeatin (tZ) increased with flower development, and the concentration of iP decreased with seed development, while that of tZ increased. We further analyzed the function of JcCYP735A using the CRISPR-Cas9 system, and found that the concentrations of tZ and tZ-riboside decreased significantly in the Jccyp735a mutants, which showed severely retarded growth. These findings will be helpful for further studies of the functions of cytokinin metabolic genes and understanding the roles of cytokinins in Jatropha growth and development.