出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/02/24 12:57:58」(JST)[Wiki en表示]
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- 1. メトヘモグロビン血症の臨床的特徴、診断、および治療 clinical features diagnosis and treatment of methemoglobinemia
- 2. メトヘモグロビン血症の遺伝学および病因 genetics and pathogenesis of methemoglobinemia
- 3. βサラセミアの病態生理 pathophysiology of beta thalassemia
- 4. 先天性赤血球増多症および真性多血症の分子学的病因 molecular pathogenesis of congenital polycythemic disorders and polycythemia vera
- 5. 薬物および毒素による外因性非自己免疫性溶血性貧血 extrinsic nonautoimmune hemolytic anemia due to drugs and toxins
- Correlating structure and function of drug-metabolizing enzymes: progress and ongoing challenges.
- Johnson EF, Connick JP, Reed JR, Backes WL, Desai MC, Xu L, Estrada DF, Laurence JS, Scott EE.Author information Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California (E.F.J.); Department of Pharmacology and Experimental Therapeutics and the Stanley S. Scott Cancer Center, Louisiana State University Health Sciences Center, New Orleans, Louisiana (J.P.C., J.R.R., W.L.B.); Department of Medicinal Chemistry, Gilead Sciences, Inc., Foster City, California (M.C.D., L.X.); Department of Pharmaceutical Chemistry (J.S.L.) and Department of Medicinal Chemistry (D.F.E., E.E.S.), University of Kansas, Lawrence, Kansas.AbstractThis report summarizes a symposium sponsored by the American Society for Pharmacology and Experimental Therapeutics at Experimental Biology held April 20-24 in Boston, MA. Presentations discussed the status of cytochrome P450 (P450) knowledge, emphasizing advances and challenges in relating structure with function and in applying this information to drug design. First, at least one structure of most major human drug-metabolizing P450 enzymes is known. However, the flexibility of these active sites can limit the predictive value of one structure for other ligands. A second limitation is our coarse-grain understanding of P450 interactions with membranes, other P450 enzymes, NADPH-cytochrome P450 reductase, and cytochrome b5. Recent work has examined differential P450 interactions with reductase in mixed P450 systems and P450:P450 complexes in reconstituted systems and cells, suggesting another level of functional control. In addition, protein nuclear magnetic resonance is a new approach to probe these protein/protein interactions, identifying interacting b5 and P450 surfaces, showing that b5 and reductase binding are mutually exclusive, and demonstrating ligand modulation of CYP17A1/b5 interactions. One desired outcome is the application of such information to control drug metabolism and/or design selective P450 inhibitors. A final presentation highlighted development of a CYP3A4 inhibitor that slows clearance of human immunodeficiency virus drugs otherwise rapidly metabolized by CYP3A4. Although understanding P450 structure/function relationships is an ongoing challenge, translational advances will benefit from continued integration of existing and new biophysical approaches.
- Drug metabolism and disposition: the biological fate of chemicals.Drug Metab Dispos.2014 Jan;42(1):9-22. doi: 10.1124/dmd.113.054627. Epub 2013 Oct 15.
- This report summarizes a symposium sponsored by the American Society for Pharmacology and Experimental Therapeutics at Experimental Biology held April 20-24 in Boston, MA. Presentations discussed the status of cytochrome P450 (P450) knowledge, emphasizing advances and challenges in relating structur
- PMID 24130370
- Cytochrome b5 reductase 2 is a novel candidate tumor suppressor gene frequently inactivated by promoter hypermethylation in human nasopharyngeal carcinoma.
- Xiao X, Zhao W, Tian F, Zhou X, Zhang J, Huang T, Hou B, Du C, Wang S, Mo Y, Yu N, Zhou S, You J, Zhang Z, Huang G, Zeng X.Author information Department of Otolaryngology-Head and Neck Surgery, First Affiliated Hospital of Guangxi Medical University, 6# Shuangyong Road, Nanning, 530021, China.AbstractCytochrome b5 reductase 2 (CYB5R2), a member of the flavoprotein pyridine nucleotide cytochrome reductase family, is associated with a number of physiological reactions. However, its role in cancer, especially nasopharyngeal carcinoma (NPC), has not been addressed. Here, we investigate the transcript levels and promoter methylation status of CYB5R2 in NPC derived cell lines and tumor biopsies and experimentally address its role as a tumor suppressor gene. We find that CYB5R2 transcript levels are decreased in NPC cell lines and tumor biopsies. Promoter hypermethylation of CYB5R2 was detected in all six tested NPC cell lines and in 84 % of primary NPC tumor biopsies but not in normal nasopharyngeal epithelium. Clinically, CYB5R2 methylation was associated with lymph node metastasis in NPC patients (P < 0.05). The endogenous expression of CYB5R2 could be restored in vitro by the methyltransferase inhibitor 5-aza-2'-deoxycytidine in NPC cell lines. Ectopic expression of CYB5R2 had an inhibitory effect on proliferation, clonogenicity and migration of NPC cells. Moreover, in vivo tests in nude mice indicated that ectopic expression of CYB5R2 reduces the tumorigenicity of CYB5R2-negative NPC cells. Collectively, these findings suggest that CYB5R2 may be a functional tumor suppressor gene, frequently inactivated by hypermethylation of its promoter in NPC. We report here the first instance of epigenetic downregulation in NPC tumor biopsies of a key enzyme, CYB5R2, which is responsible for the detoxification of environmental carcinogens. We propose the possibility of utilizing CYB5R2 promoter methylation as a diagnostic biomarker of NPC in the future.
- Tumour biology : the journal of the International Society for Oncodevelopmental Biology and Medicine.Tumour Biol.2013 Dec 12. [Epub ahead of print]
- Cytochrome b5 reductase 2 (CYB5R2), a member of the flavoprotein pyridine nucleotide cytochrome reductase family, is associated with a number of physiological reactions. However, its role in cancer, especially nasopharyngeal carcinoma (NPC), has not been addressed. Here, we investigate the transcrip
- PMID 24338690
- Inborn defects in the antioxidant systems of human red blood cells.
- van Zwieten R1, Verhoeven AJ2, Roos D3.Author information 1Laboratory of Red Blood Cell Diagnostics, Department of Blood Cell Research, Sanquin Blood Supply Organization, 1066 CX Amsterdam, The Netherlands. Electronic address: firstname.lastname@example.orgDepartment of Medical Biochemistry, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.3Laboratory of Red Blood Cell Diagnostics, Department of Blood Cell Research, Sanquin Blood Supply Organization, 1066 CX Amsterdam, The Netherlands.AbstractRed blood cells (RBCs) contain large amounts of iron and operate in highly oxygenated tissues. As a result, these cells encounter a continuous oxidative stress. Protective mechanisms against oxidation include prevention of formation of reactive oxygen species (ROS), scavenging of various forms of ROS, and repair of oxidized cellular contents. In general, a partial defect in any of these systems can harm RBCs and promote senescence, but is without chronic hemolytic complaints. In this review we summarize the often rare inborn defects that interfere with the various protective mechanisms present in RBCs. NADPH is the main source of reduction equivalents in RBCs, used by most of the protective systems. When NADPH becomes limiting, red cells are prone to being damaged. In many of the severe RBC enzyme deficiencies, a lack of protective enzyme activity is frustrating erythropoiesis or is not restricted to RBCs. Common hereditary RBC disorders, such as thalassemia, sickle-cell trait, and unstable hemoglobins, give rise to increased oxidative stress caused by free heme and iron generated from hemoglobin. The beneficial effect of thalassemia minor, sickle-cell trait, and glucose-6-phosphate dehydrogenase deficiency on survival of malaria infection may well be due to the shared feature of enhanced oxidative stress. This may inhibit parasite growth, enhance uptake of infected RBCs by spleen macrophages, and/or cause less cytoadherence of the infected cells to capillary endothelium.
- Free radical biology & medicine.Free Radic Biol Med.2013 Dec 6. pii: S0891-5849(13)01527-X. doi: 10.1016/j.freeradbiomed.2013.11.022. [Epub ahead of print]
- Red blood cells (RBCs) contain large amounts of iron and operate in highly oxygenated tissues. As a result, these cells encounter a continuous oxidative stress. Protective mechanisms against oxidation include prevention of formation of reactive oxygen species (ROS), scavenging of various forms of RO
- PMID 24316370
- Comparison of CYP3A4 and CYP3A5: The Effects of Cytochrome b5 and NADPH-cytochrome P450 Reductase on Testosterone Hydroxylation Activities
- Drug Metabolism and Pharmacokinetics 27(6), 663-667, 2012
- … CYP3A4 and CYP3A5 require cytochrome b5 (b5) and NADPH-cytochrome P450 oxidoreductase (CPR) for optimum metabolism, but little is known about the specific requirements for b5 and CPR to produce optimal activities for these enzymes. …
- NAID 130004933519
- Alteration of drug metabolizing enzymes in sulphite oxidase deficiency
- , , , , ,
- Journal of Clinical Biochemistry and Nutrition 51(1), 50-54, 2012
- … Then, aminopyrine N-demethylase, aniline 4-hydroxylase, aromatase, caffeine N-demethylase, cytochrome b5 reductase, erythromycin N-demethylase, ethoxyresorufin O-deethylase, glutathione S-transferase, N-nitrosodimethylamine N-demethylase and penthoxyresorufin O-deethylase activities were determined to follow changes in the activity of drug metabolizing enzymes in SOX-deficient rats. …
- NAID 130004879284
- Occurrence of NADH-specific and NADH/NADPH-bispecific cytochrome b5 reductases in the ascidians, Styela plicata and Ciona intestinalis
- 指吸 俊次,山中 宗,栗田 健一 [他]
- 岡山理科大学紀要 A (44), 39-44, 2008
- NAID 40016649403
- シトクロムb5レダクターゼ. NADH cytochrome B5 reductase 1UMK.png · 赤血球メト ヘモグロビンレダクターゼのリボン図とFAD。PDB 1UMKより。 識別子. EC番号 · 1.6. 2.2 · CAS登録番号 · 9032-25-1. データベース. IntEnz · IntEnz view · BRENDA ...
- Cytochrome-b5 reductase (also known as methemoglobin reductase) is a NADH- dependent enzyme that converts methemoglobin to hemoglobin. It contains FAD and catalyzes the reaction: ...