The Experts below are selected from a list of 118548 Experts worldwide ranked by ideXlab platform
Masahiro Okuda - One of the best experts on this subject based on the ideXlab platform.
-
temporary decrease in tacrolimus clearance in Cytochrome P450 3A5 non expressors early after living donor kidney transplantation effect of interleukin 6 induced suppression of the Cytochrome P450 3a gene
Basic & Clinical Pharmacology & Toxicology, 2021Co-Authors: Tomoyuki Enokiya, Masahiro Okuda, Yoshiki Sugimura, Kohei Nishikawa, Yugo Hamada, Kenji IkemuraAbstract:Tacrolimus is important for immunosuppression in kidney transplantation. In this historical cohort and in vitro study, we evaluated the changes in tacrolimus pharmacokinetics early after living donor kidney transplantation and the effects of interleukin (IL)-6 on Cytochrome P450 3A4 (CYP3A4) and Cytochrome P450 3A5 (CYP3A5) expression. In the historical cohort study, 22 patients who met the inclusion criteria were classified into CYP3A5 expressors and non-expressors (n = 16 and 6, respectively). The blood tacrolimus concentration per dose ratio (C/D) temporarily increased post-kidney transplantation on days 3-4 only in CYP3A5 non-expressors. The effects of IL-6 on CYP3A4 and CYP3A5 expression were also investigated in vitro using HepG2 and Caco-2 cells. IL-6 induced a significant concentration- and time-dependent decrease in CYP3A4 and CYP3A5 expression in both cells. The mean CYP3A4 expression level at 12 hours after IL-6 exposure (% of 0 hour) was 44.0 and 62.6 in HepG2 and Caco-2 cells, respectively, whereas the CYP3A5 expression level was 30.7 and 52.4, respectively. We hypothesize that CYP3A5 non-expressors might exhibit a temporary decrease in the oral clearance of tacrolimus via an increase in serum IL-6 concentrations early after kidney transplantation. These results may help develop strategies to improve kidney transplant outcome.
-
immune response following liver transplantation compared to kidney transplantation usefulness of monitoring peripheral blood cd4 adenosine triphosphate activity and Cytochrome P450 3A5 genotype assay
Clinical & Developmental Immunology, 2013Co-Authors: Yu Nobuoka, Shugo Mizuno, Kouhei Nishikawa, Kaname Nakatani, Yuichi Muraki, Tomomi Yamada, Masahiro Okuda, Tsutomu Nobori, Yoshiki Sugimura, Shuji IsajiAbstract:Seventy living donor liver transplantation (LDLT) and 39 kidney transplantation (KT) patients were randomly screened by using the peripheral blood CD4+ adenosine triphosphate activity (ATP) assay (IMK assay). The patients were divided into 2 groups in each organ transplantation with low IMK ATP level ( 225) (LT-L: n = 23, KT-L: n = 19, LT-H: n = 47, and KT-H: n = 20, resp.). The incidence of bacterial and/or viral infection was significantly higher in LT-L group than in LT-H group (74.0 versus 8.5%: P < 0.001). Occurrence of total viral infection in KT-L was also significantly higher than that in KT-H (36.8 versus 10%: P = 0.046). The sensitivity and specificity of the IMK assay for identifying risk of infection was 0.810 and 0.878 in LDLT patients and 0.727 and 0.607 in KT patients. The percentage of LDLT patients with Cytochrome P450 3A5 (CYP3A5) *1/*1 or *1/*3 genotype (expressors) was significantly higher in LT-L group than in LT-H group (53.8 versus 20.7%: P = 0.032). In both LDLT and KT patients, the IMK assay can be useful for monitoring immunological aspects of bacterial and/or viral infection. CYP3A5 expressors in LT-L group are related to postoperative infections.
William C Wright - One of the best experts on this subject based on the ideXlab platform.
-
unraveling the structural basis of selective inhibition of human Cytochrome P450 3A5
Journal of the American Chemical Society, 2021Co-Authors: Jingheng Wang, William C Wright, Jude Chenge, Sergio C Chai, Andrew D. Huber, Cameron D Buchman, Jayaraman Seetharaman, Darcie J Miller, Efren Garciamaldonado, Taosheng ChenAbstract:The human Cytochrome P450 (CYP) CYP3A4 and CYP3A5 enzymes metabolize more than one-half of marketed drugs. They share high structural and substrate similarity and are often studied together as CYP3A4/5. However, CYP3A5 preferentially metabolizes several clinically prescribed drugs, such as tacrolimus. Genetic polymorphism in CYP3A5 makes race-based dosing adjustment of tacrolimus necessary to minimize acute rejection after organ transplantation. Moreover, the differential tissue distribution and expression levels of CYP3A4 and CYP3A5 can aggravate toxicity during treatment. Therefore, selective inhibitors of CYP3A5 are needed to distinguish the role of CYP3A5 from that of CYP3A4 and serve as starting points for potential therapeutic development. To this end, we report the crystal structure of CYP3A5 in complex with a previously reported selective inhibitor, clobetasol propionate (CBZ). This is the first CYP3A5 structure with a type I inhibitor, which along with the previously reported substrate-free and type II inhibitor-bound structures, constitute the main CYP3A5 structural modalities. Supported by structure-guided mutagenesis analyses, the CYP3A5-CBZ structure showed that a unique conformation of the F-F' loop in CYP3A5 enables selective binding of CBZ to CYP3A5. Several polar interactions, including hydrogen bonds, stabilize the position of CBZ to interact with this unique F-F' loop conformation. In addition, functional and biophysical assays using CBZ analogs highlight the importance of heme-adjacent moieties for selective CYP3A5 inhibition. Our findings can be used to guide further development of more potent and selective CYP3A5 inhibitors.
-
clobetasol propionate is a heme mediated selective inhibitor of human Cytochrome P450 3A5
Journal of Medicinal Chemistry, 2020Co-Authors: William C Wright, Jude Chenge, Jingheng Wang, Hazel M Girvan, Sergio C Chai, Andrew D. Huber, Jing Wu, Lei Yang, Peter OladimejiAbstract:The human Cytochrome P450 (CYP) enzymes CYP3A4 and CYP3A5 metabolize most drugs and have high similarities in their structure and substrate preference. Whereas CYP3A4 is predominantly expressed in the liver, CYP3A5 is upregulated in cancer, contributing to drug resistance. Selective inhibitors of CYP3A5 are, therefore, critical to validating it as a therapeutic target. Here we report clobetasol propionate (clobetasol) as a potent and selective CYP3A5 inhibitor identified by high-throughput screening using enzymatic and cell-based assays. Molecular dynamics simulations suggest a close proximity of clobetasol to the heme in CYP3A5 but not in CYP3A4. UV–visible spectroscopy and electron paramagnetic resonance analyses confirmed the formation of an inhibitory type I heme–clobetasol complex in CYP3A5 but not in CYP3A4, thus explaining the CYP3A5 selectivity of clobetasol. Our results provide a structural basis for selective CYP3A5 inhibition, along with mechanistic insights, and highlight clobetasol as an impo...
-
clobetasol propionate is a heme mediated selective inhibitor of human Cytochrome P450 3A5
Journal of Medicinal Chemistry, 2020Co-Authors: William C Wright, Jude Chenge, Jingheng Wang, Hazel M Girvan, Sergio C Chai, Peter Oladimeji, Andrew D. Huber, Lei Yang, Andrew W MunroAbstract:The human Cytochrome P450 (CYP) enzymes CYP3A4 and CYP3A5 metabolize most drugs and have high similarities in their structure and substrate preference. Whereas CYP3A4 is predominantly expressed in the liver, CYP3A5 is upregulated in cancer, contributing to drug resistance. Selective inhibitors of CYP3A5 are, therefore, critical to validating it as a therapeutic target. Here we report clobetasol propionate (clobetasol) as a potent and selective CYP3A5 inhibitor identified by high-throughput screening using enzymatic and cell-based assays. Molecular dynamics simulations suggest a close proximity of clobetasol to the heme in CYP3A5 but not in CYP3A4. UV-visible spectroscopy and electron paramagnetic resonance analyses confirmed the formation of an inhibitory type I heme-clobetasol complex in CYP3A5 but not in CYP3A4, thus explaining the CYP3A5 selectivity of clobetasol. Our results provide a structural basis for selective CYP3A5 inhibition, along with mechanistic insights, and highlight clobetasol as an important chemical tool for target validation.
Wan Gyoon Shin - One of the best experts on this subject based on the ideXlab platform.
-
prediction of the tacrolimus population pharmacokinetic parameters according to cyp3A5 genotype and clinical factors using nonmem in adult kidney transplant recipients
European Journal of Clinical Pharmacology, 2013Co-Authors: Nayoung Han, Hwiyeol Yun, Jinyi Hong, Inwha Kim, Su Hyun Hong, Yon Su Kim, Wan Gyoon ShinAbstract:Purpose Tacrolimus is a commonly used immunosuppressant in solid organ transplantation recipients, but it is characterized by a narrow therapeutic range and large inter-individual variability. The purpose of this study was to establish a population pharmacokinetic (PK) model of tacrolimus and evaluate the influence of clinical covariates, including the genetic polymorphisms of the Cytochrome P450 3A5 gene (CYP3A5) and gene encoding P-glycoprotein (ABCB1), on the PK parameters in adult Korean kidney transplant recipients.
-
prediction of the tacrolimus population pharmacokinetic parameters according to cyp3A5 genotype and clinical factors using nonmem in adult kidney transplant recipients
European Journal of Clinical Pharmacology, 2013Co-Authors: Nayoung Han, Hwiyeol Yun, Jinyi Hong, Inwha Kim, Su Hyun Hong, Yon Su Kim, Wan Gyoon ShinAbstract:Tacrolimus is a commonly used immunosuppressant in solid organ transplantation recipients, but it is characterized by a narrow therapeutic range and large inter-individual variability. The purpose of this study was to establish a population pharmacokinetic (PK) model of tacrolimus and evaluate the influence of clinical covariates, including the genetic polymorphisms of the Cytochrome P450 3A5 gene (CYP3A5) and gene encoding P-glycoprotein (ABCB1), on the PK parameters in adult Korean kidney transplant recipients. Clinical data were collected retrospectively for 400 days after the initiation of a tacrolimus-based immunosuppression therapy. Data from 2,788 trough blood samples obtained from 80 subjects were used to perform a population PK analysis with a nonlinear mixed-effect model (NONMEM). The estimated population mean values of clearance (CL/F) and volume of distribution (V/F) were 22.9 L/h and 716 L, respectively, and the k a was fixed to 4.5 h-1. The CYP3A5 genotype, hematocrit level, and post-operative days were identified as the main covariates that influence CL/F, and body weight was found to have a significant effect on V/F. Other covariates, including ABCB1 genotype, corticosteroid dosage, sex, and other clinical data, did not contribute to the pharmacokinetics of tacrolimus. This tacrolimus population PK model will be a valuable tool in developing rational guidelines and provides a basis for individualized therapy after kidney transplantation in clinical settings of Korea.
Shugo Mizuno - One of the best experts on this subject based on the ideXlab platform.
-
immune response following liver transplantation compared to kidney transplantation usefulness of monitoring peripheral blood cd4 adenosine triphosphate activity and Cytochrome P450 3A5 genotype assay
Clinical & Developmental Immunology, 2013Co-Authors: Yu Nobuoka, Shugo Mizuno, Kouhei Nishikawa, Kaname Nakatani, Yuichi Muraki, Tomomi Yamada, Masahiro Okuda, Tsutomu Nobori, Yoshiki Sugimura, Shuji IsajiAbstract:Seventy living donor liver transplantation (LDLT) and 39 kidney transplantation (KT) patients were randomly screened by using the peripheral blood CD4+ adenosine triphosphate activity (ATP) assay (IMK assay). The patients were divided into 2 groups in each organ transplantation with low IMK ATP level ( 225) (LT-L: n = 23, KT-L: n = 19, LT-H: n = 47, and KT-H: n = 20, resp.). The incidence of bacterial and/or viral infection was significantly higher in LT-L group than in LT-H group (74.0 versus 8.5%: P < 0.001). Occurrence of total viral infection in KT-L was also significantly higher than that in KT-H (36.8 versus 10%: P = 0.046). The sensitivity and specificity of the IMK assay for identifying risk of infection was 0.810 and 0.878 in LDLT patients and 0.727 and 0.607 in KT patients. The percentage of LDLT patients with Cytochrome P450 3A5 (CYP3A5) *1/*1 or *1/*3 genotype (expressors) was significantly higher in LT-L group than in LT-H group (53.8 versus 20.7%: P = 0.032). In both LDLT and KT patients, the IMK assay can be useful for monitoring immunological aspects of bacterial and/or viral infection. CYP3A5 expressors in LT-L group are related to postoperative infections.
-
immunological aspects in late phase of living donor liver transplant patients usefulness of monitoring peripheral blood cd4 adenosine triphosphate activity
Clinical & Developmental Immunology, 2013Co-Authors: Shugo Mizuno, Kaname Nakatani, Yuichi Muraki, Akihiro Tanemura, Naohisa Kuriyama, Ichiro Ohsawa, Yoshinori Azumi, Masashi Kishiwada, Masanobu Usui, Hiroyuki SakuraiAbstract:Aim. To evaluate whether the combination of the peripheral blood CD4+ adenosine triphosphate activity (ATP) assay (ImmuKnow assay: IMK assay) and Cytochrome P450 3A5 (CYP3A5) genotype assay is useful for monitoring of immunological aspects in the patient followup of more than one year after living donor liver transplantation (LDLT). Methods. Forty-nine patients, who underwent LDLT more than one year ago, were randomly screened by using IMK assay from January 2010 to December 2011, and the complete medical records of each patient were obtained. The CYP3A5 genotypes were examined in thirty-nine patients of them. Results. The mean ATP level of the IMK assay was significantly lower in the patients with infection including recurrence of hepatitis C (HCV) (n = 10) than in those without infection (n = 39): 185 versus 350 ng/mL (P < 0.001), while it was significantly higher in the patients with rejection (n = 4) than in those without rejection (n = 45): 663 versus 306 ng/mL (P < 0.001). The IMK assay showed favorable sensitivity/specificity for infection (0.909/0.842) as well as acute rejection (1.0/0.911). CYP3A5 genotypes in both recipient and donor did not affect incidence of infectious complications. Conclusions. In the late phase of LDLT patients, the IMK assay is very useful for monitoring immunological aspects including bacterial infection, recurrence of HCV, and rejection.
F P Guengerich - One of the best experts on this subject based on the ideXlab platform.
-
expression of Cytochrome P450 3A5 in escherichia coli effects of 5 modification purification spectral characterization reconstitution conditions and catalytic activities
Archives of Biochemistry and Biophysics, 1995Co-Authors: Elizabeth M J Gillam, Wd Hooper, Hiroshi Yamazaki, Zuyu Guo, Yuenfang Ueng, Ian Edwin Cock, Paul E B Reilly, F P GuengerichAbstract:Cytochrome P450 (P450) 3A5 is a human enzyme with 85% amino acid sequence identity to the more predominantly expressed P450 3A4 and has been reported to have overlapping catalytic specificity. The 5'-terminus of a P450 3A5 cDNA was modified for optimal expression in Escherichia coli using the vector pCW, by aligning the MALLLAVFL N-terminal sequence of recombinant bovine P450 17A (H. J. Barnes, M. P. Arlotto, and M. R. Waterman, (1991) Proc. Natl. Acad. Sci. USA 88, 5597-5601) to the 3A5 cDNA. Two constructs were made, differing by their identity with the modified 3A4 N-terminal sequence (E. M. J. Gillam, T. Baba, B-R. Kim, S. Ohmori, and F. P. Guengerich, (1993) Arch. Biochem. Biophys. 305, 123-131). The first modified sequence (3A5#1) was identical to recombinant P450 3A4 up to codon 15, the 3A5 sequence being introduced thereafter. In the other (3A5#2), the successful 3A4 N-terminal nucleotide sequence was attached to codon 30. The yield was greater than fourfold higher in the first construct [up to 260 nmol (liter culture)-1]. The recombinant P450 3A5 (construct 1) was purified to electrophoretic homogeneity using a variation of a three-step procedure developed previously for P450 3A4, with an overall yield of approximately 40%. Purified P450 3A5 was active in nifedipine oxidation, testosterone 6 beta-hydroxylation, aflatoxin 3 alpha-hydroxylation and 8,9-epoxidation, ethylmorphine N-demethylation, erythromycin N-demethylation, and d-benzphetamine N-demethylation. The reconstitution of nifedipine oxidation, testosterone 6 beta-hydroxylation, and the aflatoxin oxidation activities showed dependence upon the presence of Cytochrome b5, divalent cations, phospholipid mixtures, glutathione, and cholate similar to that previously found for purified P450 3A4. However, rates of the N-demethylations of ethylmorphine, erythromycin, and d-benzphetamine were as high or higher for P450 3A5 than P450 3A4 and were not particularly dependent upon modifications of reconstitution systems [corrected].
-
Expression of Cytochrome-P450-3A5 in Escherichia-Coli - Effects of 5' Modification, Purification, Spectral Characterization, Reconstitution Conditions, and Catalytic Activities (Vol 317, Pg 374, 1995)
'Elsevier BV', 1995Co-Authors: Gillam Emj, Reilly Peb, Zy Guo, Yf Ueng, Yamazaki H, Wd Hooper, F P GuengerichAbstract:Cytochrome P450 (P450) 3A5 is a human enzyme with 85% amino acid sequence identity to the more predominantly expressed P450 3A4 and has been reported to have overlapping catalytic specificity. The 5'-terminus of a P450 3A5 cDNA was modified for optimal expression in Escherichia coli using the vector pCW, by aligning the MALLLAVFL N-terminal sequence of recombinant bovine P450 17A (H. J. Barnes, M. P. Arlotto, and M. R. Waterman, (1991) Proc. Natl. Acad. Sci. USA 88, 5597-5601) to the 3A5 cDNA. Two constructs were made, differing by their identity with the modified 3A4 N-terminal sequence (E. M. J. Gillam, T. Baba, B-R. Rim, S. Ohmori, and F. P. Guengerich, (1993) Arch. Biochem. Biophys. 305, 123-131). The first modified sequence (3A5#1) was identical to recombinant P450 3A4 up to codon 15, the 3A5 sequence being introduced thereafter. In the other (3A5#2), the successful 3A4 N-terminal nucleotide sequence was attached to codon 30. The yield was greater than fourfold higher in the first construct [up to 260 nmol (liter culture)(-1)]. The recombinant P450 3A5 (construct 1) was purified to electrophoretic homogeneity using a variation of a three-step procedure developed previously for P450 3A4, with an overall yield of similar to 40%. Purified P450 3A5 was active in nifedipine oxidation, testosterone 6 beta-hydroxylation, aflatoxin 3 alpha-hydroxylation and 8,9-epoxidation, N-ethylmorphine N-demethylation, erythromycin N-demethylation, and d-benzphetamine N-demethylation. The reconstitution of nifedipine oxidation, testosterone 6 beta-hydroxylation, and the aflatoxin oxidation activities showed dependence upon the presence of Cytochrome b(5), divalent cations, phospholipid mixtures, glutathione, and cholate similar to that previously found for purified P450 3A4. However, rates of the N-demethylations of N-ethylmorphine, erythromycin, and d-benzphetamine were as high or higher for P450 3A5 than P450 3A4 and were not particularly dependent upon modifications of reconstitution systems. (C) 1995 Academic Press, Inc
