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Arsenault PR, Song D, Bergkamp M, Ravaschiere AM, Navalsky BE, Lieberman PM, Lee FS. Identification of Small-Molecule PHD2 Zinc Finger Inhibitors that Activate Hypoxia Inducible Factor. Chembiochem 2016; 17:2316-2323. [PMID: 27770548 DOI: 10.1002/cbic.201600493] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Indexed: 02/06/2023]
Abstract
The prolyl hydroxylase domain (PHD) protein:hypoxia inducible factor (HIF) pathway is the main pathway by which changes in oxygen concentration are transduced to changes in gene expression. In mammals, there are three PHD paralogues, and PHD2 has emerged as a particularly critical one for regulating HIF target genes such as erythropoietin (EPO), which controls red cell mass and hematocrit. PHD2 is distinctive among the three PHDs in that it contains an N-terminal MYND-type zinc finger. We have proposed that this zinc finger binds a Pro-Xaa-Leu-Glu (PXLE) motif found in proteins of the HSP90 pathway to facilitate HIF-α hydroxylation. Targeting this motif could provide a means of specifically inhibiting this PHD isoform. Here, we screened a library of chemical compounds for their capacity to inhibit the zinc finger of PHD2. We identified compounds that, in vitro, can inhibit PHD2 binding to a PXLE-containing peptide and induce activation of HIF. Injection of one of these compounds into mice induces an increase in hematocrit. This study offers proof of principle that inhibition of the zinc finger of PHD2 can provide a means of selectively targeting PHD2 to activate the HIF pathway.
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Affiliation(s)
- Patrick R Arsenault
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, 605 Stellar Chance Labs, 422 Curie Blvd, Philadelphia, PA, 19104, USA
| | - Daisheng Song
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, 605 Stellar Chance Labs, 422 Curie Blvd, Philadelphia, PA, 19104, USA
| | - Marian Bergkamp
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, 605 Stellar Chance Labs, 422 Curie Blvd, Philadelphia, PA, 19104, USA
| | - Andrew M Ravaschiere
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, 605 Stellar Chance Labs, 422 Curie Blvd, Philadelphia, PA, 19104, USA
| | - Bradleigh E Navalsky
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, 605 Stellar Chance Labs, 422 Curie Blvd, Philadelphia, PA, 19104, USA
| | - Paul M Lieberman
- The Wistar Institute, 3601 Spruce St., Philadelphia, PA, 19104, USA
| | - Frank S Lee
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, 605 Stellar Chance Labs, 422 Curie Blvd, Philadelphia, PA, 19104, USA
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Arsenault PR, Heaton-Johnson KJ, Li LS, Song D, Ferreira VS, Patel N, Master SR, Lee FS. Identification of prolyl hydroxylation modifications in mammalian cell proteins. Proteomics 2015; 15:1259-67. [PMID: 25421965 DOI: 10.1002/pmic.201400398] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 09/17/2014] [Accepted: 11/20/2014] [Indexed: 01/22/2023]
Abstract
Prolyl hydroxylation is a PTM that plays an important role in the formation of collagen fibrils and in the oxygen-dependent regulation of hypoxia inducible factor-α (HIF-α). While this modification has been well characterized in the context of these proteins, it remains unclear to what extent it occurs in the remaining mammalian proteome. We explored this question using MS to analyze cellular extracts subjected to various fractionation strategies. In one strategy, we employed the von Hippel Lindau tumor suppressor protein, which recognizes prolyl hydroxylated HIF-α, as a scaffold for generating hydroxyproline capture reagents. We report novel sites of prolyl hydroxylation within five proteins: FK506-binding protein 10, myosin heavy chain 10, hexokinase 2, pyruvate kinase, and C-1 Tetrahydrofolate synthase. Furthermore, we show that identification of prolyl hydroxylation presents a significant technical challenge owing to widespread isobaric methionine oxidation, and that manual inspection of spectra of modified peptides in this context is critical for validation.
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Affiliation(s)
- Patrick R Arsenault
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, PA, USA
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Gardie B, Percy MJ, Hoogewijs D, Chowdhury R, Bento C, Arsenault PR, Richard S, Almeida H, Ewing J, Lambert F, McMullin MF, Schofield CJ, Lee FS. The role of PHD2 mutations in the pathogenesis of erythrocytosis. Hypoxia (Auckl) 2014; 2:71-90. [PMID: 27774468 PMCID: PMC5045058 DOI: 10.2147/hp.s54455] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The transcription of the erythropoietin (EPO) gene is tightly regulated by the hypoxia response pathway to maintain oxygen homeostasis. Elevations in serum EPO level may be reflected in an augmentation in the red cell mass, thereby causing erythrocytosis. Studies on erythrocytosis have provided insights into the function of the oxygen-sensing pathway and the critical proteins involved in the regulation of EPO transcription. The α subunits of the hypoxia-inducible transcription factor are hydroxylated by three prolyl hydroxylase domain (PHD) enzymes, which belong to the iron and 2-oxoglutarate-dependent oxygenase superfamily. Sequence analysis of the genes encoding the PHDs in patients with erythrocytosis has revealed heterozygous germline mutations only occurring in Egl nine homolog 1 (EGLN1, also known as PHD2), the gene that encodes PHD2. To date, 24 different EGLN1 mutations comprising missense, frameshift, and nonsense mutations have been described. The phenotypes associated with the patients carrying these mutations are fairly homogeneous and typically limited to erythrocytosis with normal to elevated EPO. However, exceptions exist; for example, there is one case with development of concurrent paraganglioma (PHD2-H374R). Analysis of the erythrocytosis-associated PHD2 missense mutations has shown heterogeneous results. Structural studies reveal that mutations can affect different domains of PHD2. Some are close to the hypoxia-inducible transcription factor α/2-oxoglutarate or the iron binding sites for PHD2. In silico studies demonstrate that the mutations do not always affect fully conserved residues. In vitro and in cellulo studies showed varying effects of the mutations, ranging from mild effects to severe loss of function. The exact mechanism of a potential tumor-suppressor role for PHD2 still needs to be elucidated. A knockin mouse model expressing the first reported PHD2-P317R mutation recapitulates the phenotype observed in humans (erythrocytosis with inappropriately normal serum EPO levels) and demonstrates that haploinsufficiency and partial deregulation of PHD2 is sufficient to cause erythrocytosis.
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Affiliation(s)
- Betty Gardie
- Laboratoire de Génétique Oncologique de l'Ecole Pratique des Hautes Etudes, Villejuif; Unité Mixte de Recherche, Institut national de la santé et de la recherche médicale U892, Centre national de la recherche scientifique 6299, Centre de Recherche en Cancérologie Nantes/Angers, Université de Nantes, Nantes, France
| | - Melanie J Percy
- Department of Haematology, Belfast City Hospital, Belfast, UK
| | - David Hoogewijs
- Institute of Physiology and Zürich Center for Integrative Human Physiology, University of Zürich, Zürich, Switzerland
| | - Rasheduzzaman Chowdhury
- Department of Chemistry and Oxford Centre for Integrative Systems Biology, Chemistry Research Laboratory, University of Oxford, Oxford, UK
| | - Celeste Bento
- Department of Hematology, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
| | - Patrick R Arsenault
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Stéphane Richard
- Laboratoire de Génétique Oncologique de l'Ecole Pratique des Hautes Etudes, Villejuif; Institut national de la santé et de la recherche médicale U753, Institut de cancérologie Gustave Roussy (IGR), Villejuif, France; Faculté de Médecine Paris-Sud, Le Kremlin-Bicêtre, France
| | - Helena Almeida
- Department of Hematology, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
| | | | - Frédéric Lambert
- Center for Human Genetics, Pathology Institute, UniLab-Lg, Molecular Haemato-Oncology Unit, CHU of Liege, Liege, Belgium
| | | | - Christopher J Schofield
- Department of Chemistry and Oxford Centre for Integrative Systems Biology, Chemistry Research Laboratory, University of Oxford, Oxford, UK
| | - Frank S Lee
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Song D, Li LS, Arsenault PR, Tan Q, Bigham AW, Heaton-Johnson KJ, Master SR, Lee FS. Defective Tibetan PHD2 binding to p23 links high altitude adaption to altered oxygen sensing. J Biol Chem 2014; 289:14656-65. [PMID: 24711448 PMCID: PMC4031521 DOI: 10.1074/jbc.m113.541227] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 03/14/2014] [Indexed: 12/11/2022] Open
Abstract
The Tibetan population has adapted to the chronic hypoxia of high altitude. Tibetans bear a genetic signature in the prolyl hydroxylase domain protein 2 (PHD2/EGLN1) gene, which encodes for the central oxygen sensor of the hypoxia-inducible factor (HIF) pathway. Recent studies have focused attention on two nonsynonymous coding region substitutions, D4E and C127S, both of which are markedly enriched in the Tibetan population. These amino acids reside in a region of PHD2 that harbors a zinc finger, which we have previously discovered binds to a Pro-Xaa-Leu-Glu (PXLE) motif in the HSP90 cochaperone p23, thereby recruiting PHD2 to the HSP90 pathway to facilitate HIF-α hydroxylation. We herein report that the Tibetan PHD2 haplotype (D4E/C127S) strikingly diminishes the interaction of PHD2 with p23, resulting in impaired PHD2 down-regulation of the HIF pathway. The defective binding to p23 depends on both the D4E and C127S substitutions. We also identify a PXLE motif in HSP90 itself that can mediate binding to PHD2 but find that this interaction is maintained with the D4E/C127S PHD2 haplotype. We propose that the Tibetan PHD2 variant is a loss of function (hypomorphic) allele, leading to augmented HIF activation to facilitate adaptation to high altitude.
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Affiliation(s)
- Daisheng Song
- From the Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 and
| | - Lin-sheng Li
- From the Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 and
| | - Patrick R Arsenault
- From the Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 and
| | - Qiulin Tan
- From the Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 and
| | - Abigail W Bigham
- the Department of Anthropology, University of Michigan, Ann Arbor, Michigan 48109
| | - Katherine J Heaton-Johnson
- From the Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 and
| | - Stephen R Master
- From the Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 and
| | - Frank S Lee
- From the Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 and
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Arsenault PR, Pei F, Lee R, Kerestes H, Percy MJ, Keith B, Simon MC, Lappin TRJ, Khurana TS, Lee FS. A knock-in mouse model of human PHD2 gene-associated erythrocytosis establishes a haploinsufficiency mechanism. J Biol Chem 2013; 288:33571-33584. [PMID: 24121508 DOI: 10.1074/jbc.m113.482364] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The central pathway for controlling red cell mass is the PHD (prolyl hydroxylase domain protein):hypoxia-inducible factor (HIF) pathway. HIF, which is negatively regulated by PHD, activates numerous genes, including ones involved in erythropoiesis, such as the ERYTHROPOIETIN (EPO) gene. Recent studies have implicated PHD2 as the key PHD isoform regulating red cell mass. Studies of humans have identified erythrocytosis-associated, heterozygous point mutations in the PHD2 gene. A key question concerns the mechanism by which human mutations lead to phenotypes. In the present report, we generated and characterized a mouse line in which a P294R knock-in mutation has been introduced into the mouse Phd2 locus to model the first reported human PHD2 mutation (P317R). Phd2(P294R/+) mice display a degree of erythrocytosis equivalent to that seen in Phd2(+/-) mice. The Phd2(P294R/+)-associated erythrocytosis is reversed in a Hif2a(+/-), but not a Hif1a(+/-) background. Additional studies using various conditional knock-outs of Phd2 reveal that erythrocytosis can be induced by homozygous and heterozygous knock-out of Phd2 in renal cortical interstitial cells using a Pax3-Cre transgene or by homozygous knock-out of Phd2 in hematopoietic progenitors driven by a Vav1-Cre transgene. These studies formally prove that a missense mutation in PHD2 is the cause of the erythrocytosis, show that this occurs through haploinsufficiency, and point to multifactorial control of red cell mass by PHD2.
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Affiliation(s)
- Patrick R Arsenault
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Fei Pei
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Rebecca Lee
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Heddy Kerestes
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Melanie J Percy
- Department of Haematology, Belfast City Hospital, Belfast, Northern Ireland BT9 7AB, United Kingdom
| | - Brian Keith
- Department of Cancer Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104; Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - M Celeste Simon
- Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104; Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104; Howard Hughes Medical Institute, Philadelphia, Pennsylvania 19104
| | - Terence R J Lappin
- Centre for Cancer Research and Cell Biology, Queen's University, Belfast, Northern Ireland BT9 7BL, United Kingdom
| | - Tejvir S Khurana
- Department of Physiology and Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Frank S Lee
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104.
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Song D, Li LS, Heaton-Johnson KJ, Arsenault PR, Master SR, Lee FS. Prolyl hydroxylase domain protein 2 (PHD2) binds a Pro-Xaa-Leu-Glu motif, linking it to the heat shock protein 90 pathway. J Biol Chem 2013; 288:9662-9674. [PMID: 23413029 DOI: 10.1074/jbc.m112.440552] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Prolyl hydroxylase domain protein 2 (PHD2, also known as Egg Laying Defective Nine homolog 1) is a key oxygen-sensing protein in metazoans. In an oxygen-dependent manner, PHD2 site-specifically prolyl hydroxylates the master transcription factor of the hypoxic response, hypoxia-inducible factor-α (HIF-α), thereby targeting HIF-α for degradation. In this report we show that the heat shock protein 90 (HSP90) co-chaperones p23 and FKBP38 interact via a conserved Pro-Xaa-Leu-Glu motif (where Xaa = any amino acid) in these proteins with the N-terminal Myeloid Nervy and DEAF-1 (MYND)-type zinc finger of PHD2. Knockdown of p23 augments hypoxia-induced HIF-1α protein levels and HIF target genes. We propose that p23 recruits PHD2 to the HSP90 machinery to facilitate HIF-1α hydroxylation. These findings identify a link between two ancient pathways, the PHD:HIF and the HSP90 pathways, and suggest that this link was established concurrent with the emergence of the PHD:HIF pathway in evolution.
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Affiliation(s)
- Daisheng Song
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Lin-Sheng Li
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Katherine J Heaton-Johnson
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Patrick R Arsenault
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Stephen R Master
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Frank S Lee
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104.
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Weathers PJ, Arsenault PR, Covello PS, McMickle A, Teoh KH, Reed DW. Artemisinin production in Artemisia annua: studies in planta and results of a novel delivery method for treating malaria and other neglected diseases. Phytochem Rev 2011; 10:173-183. [PMID: 21643453 PMCID: PMC3106422 DOI: 10.1007/s11101-010-9166-0] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Artemisia annua L. produces the sesquiterpene lactone, artemisinin, a potent antimalarial drug that is also effective in treating other parasitic diseases, some viral infections and various neoplasms. Artemisinin is also an allelopathic herbicide that can inhibit the growth of other plants. Unfortunately, the compound is in short supply and thus, studies on its production in the plant are of interest as are low cost methods for drug delivery. Here we review our recent studies on artemisinin production in A. annua during development of the plant as it moves from the vegetative to reproductive stage (flower budding and full flower formation), in response to sugars, and in concert with the production of the ROS, hydrogen peroxide. We also provide new data from animal experiments that measured the potential of using the dried plant directly as a therapeutic. Together these results provide a synopsis of a more global view of regulation of artemisinin biosynthesis in A. annua than previously available. We further suggest an alternative low cost method of drug delivery to treat malaria and other neglected tropical diseases.
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Affiliation(s)
- Pamela J. Weathers
- Department of Biology/Biotechnology, Worcester Polytechnic Institute, 100 Institute Rd, Worcester, MA 01609, USA
| | - Patrick R. Arsenault
- Department of Biology/Biotechnology, Worcester Polytechnic Institute, 100 Institute Rd, Worcester, MA 01609, USA
| | - Patrick S. Covello
- Plant Biotechnology Institute, 110 Gymnasium Place, Saskatoon, SK S7N OW9, Canada
| | | | - Keat H. Teoh
- Arkansas Bioscience Institute, Jonesboro, AR 72401, USA
| | - Darwin W. Reed
- Plant Biotechnology Institute, 110 Gymnasium Place, Saskatoon, SK S7N OW9, Canada
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Nguyen KT, Arsenault PR, Weathers PJ. Trichomes + roots + ROS = artemisinin: regulating artemisinin biosynthesis in Artemisia annua L. In Vitro Cell Dev Biol Plant 2011; 47:329-338. [PMID: 21666770 PMCID: PMC3110715 DOI: 10.1007/s11627-011-9343-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Artemisinin is a highly effective sesquiterpene lactone therapeutic produced in the plant, Artemisia annua. Despite its efficacy against malaria and many other infectious diseases and neoplasms, the drug is in short supply mainly because the plant produces low levels of the compound. This review updates the current understanding of artemisinin biosynthesis with a special focus on the emerging knowledge of how biosynthesis of the compound is regulated in planta.
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Affiliation(s)
- Khanhvan T Nguyen
- Department of Biology and Biotechnology at Gateway, Worcester Polytechnic Institute, 100 Institute Rd, Worcester, MA 01609, USA
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Arsenault PR, Vail D, Wobbe KK, Erickson K, Weathers PJ. Reproductive development modulates gene expression and metabolite levels with possible feedback inhibition of artemisinin in Artemisia annua. Plant Physiol 2010; 154:958-68. [PMID: 20724645 PMCID: PMC2949044 DOI: 10.1104/pp.110.162552] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Accepted: 08/16/2010] [Indexed: 05/19/2023]
Abstract
The relationship between the transition to budding and flowering in Artemisia annua and the production of the antimalarial sesquiterpene, artemisinin (AN), the dynamics of artemisinic metabolite changes, AN-related transcriptional changes, and plant and trichome developmental changes were measured. Maximum production of AN occurs during full flower stage within floral tissues, but that changes in the leafy bracts and nonbolt leaves as the plant shifts from budding to full flower. Expression levels of early pathway genes known to be involved in isopentenyl diphosphate and farnesyl diphosphate biosynthesis leading to AN were not immediately positively correlated with either AN or its precursors. However, we found that the later AN pathway genes, amorpha-4,11-diene synthase (ADS) and the cytochrome P450, CYP71AV1 (CYP), were more highly correlated with AN's immediate precursor, dihydroartemisinic acid, within all leaf tissues tested. In addition, leaf trichome formation throughout the developmental phases of the plant also appears to be more complex than originally thought. Trichome changes correlated closely with the levels of AN but not its precursors. Differences were observed in trichome densities that are dependent both on developmental stage (vegetative, budding, and flowering) and on position (upper and lower leaf tissue). AN levels declined significantly as plants matured, as did ADS and CYP transcripts. Spraying leaves with AN or artemisinic acid inhibited CYP transcription; artemisinic acid also inhibited ADS transcription. These data allow us to present a novel model for the differential control of AN biosynthesis as it relates to developmental stage and trichome maturation and collapse.
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Arsenault PR, Vail DR, Wobbe KK, Weathers PJ. Effect of sugars on artemisinin production in Artemisia annua L.: transcription and metabolite measurements. Molecules 2010; 15:2302-18. [PMID: 20428043 PMCID: PMC3939791 DOI: 10.3390/molecules15042302] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2009] [Revised: 03/20/2010] [Accepted: 03/23/2010] [Indexed: 11/16/2022] Open
Abstract
The biosynthesis of the valuable sesquiterpene anti-malarial, artemisinin, is known to respond to exogenous sugar concentrations. Here young Artemisia annua L. seedlings (strain YU) were used to measure the transcripts of six key genes in artemisinin biosynthesis in response to growth on sucrose, glucose, or fructose. The measured genes are: from the cytosolic arm of terpene biosynthesis, 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGR), farnesyl disphosphate (FPS); from the plastid arm of terpene biosynthesis, 1-deoxyxylulose-5-phosphate synthase (DXS), 1-deoxyxylulouse 5-phosphate reductoisomerase (DXR); from the dedicated artemisinin pathway amorpha-4,11-diene synthase (ADS), and the P450, CYP71AV1 (CYP). Changes in intracellular concentrations of artemisinin (AN) and its precursors, dihydroartemisinic acid (DHAA), artemisinic acid (AA), and arteannuin B (AB) were also measured in response to these three sugars. FPS, DXS, DXR, ADS and CYP transcript levels increased after growth in glucose, but not fructose. However, the kinetics of these transcripts over 14 days was very different. AN levels were significantly increased in glucose-fed seedlings, while levels in fructose-fed seedlings were inhibited; in both conditions this response was only observed for 2 days after which AN was undetectable until day 14. In contrast to AN, on day 1 AB levels doubled in seedlings grown in fructose compared to those grown in glucose. Results showed that transcript level was often negatively correlated with the observed metabolite concentrations. When seedlings were gown in increasing levels of AN, some evidence of a feedback mechanism emerged, but mainly in the inhibition of AA production. Together these results show the complex interplay of exogenous sugars on the biosynthesis of artemisinin in young A. annua seedlings.
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Affiliation(s)
- Patrick R. Arsenault
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, WPI, 100 Institute Rd. Worcester MA 01609, USA
| | - Daniel R. Vail
- Arkansas Bioscience Institute, Arkansas State University, Jonesboro AR, 72401 USA; E-Mail: (D.R.V.)
| | - Kristin K. Wobbe
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester MA, 01609, USA; E-Mail: (K.K.W.)
| | - Pamela J. Weathers
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, WPI, 100 Institute Rd. Worcester MA 01609, USA
- Arkansas Bioscience Institute, Arkansas State University, Jonesboro AR, 72401 USA; E-Mail: (D.R.V.)
- Author to whom correspondence should be addressed; E-Mail:
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Mannan A, Liu C, Arsenault PR, Towler MJ, Vail DR, Lorence A, Weathers PJ. DMSO triggers the generation of ROS leading to an increase in artemisinin and dihydroartemisinic acid in Artemisia annua shoot cultures. Plant Cell Rep 2010; 29:143-52. [PMID: 20084379 PMCID: PMC2833288 DOI: 10.1007/s00299-009-0807-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2009] [Revised: 11/25/2009] [Accepted: 12/01/2009] [Indexed: 05/19/2023]
Abstract
The antimalarial sesquiterpene, artemisinin, is in short supply; demand is not being met, and the role of artemisinin in the plant is not well established. Prior work showed that addition of dimethyl sulfoxide (DMSO) to seedlings increased artemisinin in their shoots and this study further investigated that serendipitous observation. When in vitro-cultured Artemisia annua rooted shoots were fed different amounts of DMSO (0-2.0% v/v), artemisinin levels doubled and showed biphasic optima at 0.25 and 2.0% DMSO. Both artemisinin and its precursor, dihydroartemisinic acid, increased with the former continuing 7 days after DMSO treatment. There was no stimulation of artemisinin production in DMSO-treated unrooted shoots. The first gene in the artemisinin biosynthetic pathway, amorphadiene synthase, showed no increase in transcript level in response to DMSO compared to controls. In contrast, the second gene in the pathway, CYP71AV1, did respond to DMSO but at a level of transcripts inverse to artemisinin levels. When rooted shoots were stained for the reactive oxygen species (ROS), H2O2, ROS increased with increasing DMSO concentration; unrooted shoots produced no ROS in response to DMSO. Both the increases in DMSO-induced ROS response and corresponding artemisinin levels were inhibited by addition of vitamin C. Together these data show that at least in response to DMSO, artemisinin production and ROS increase and that when ROS is reduced, so also is artemisinin suggesting that ROS may play a role in artemisinin production in A. annua.
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Affiliation(s)
- Abdul Mannan
- Arkansas Biosciences Institute, Arkansas State University, Jonesboro, AR 72467-0639, USA
- Department of Biochemistry, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad 45320, Pakistan
| | - Chunzhao Liu
- Arkansas Biosciences Institute, Arkansas State University, Jonesboro, AR 72467-0639, USA
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, 100080 Beijing, China
| | | | | | - Dan R. Vail
- Arkansas Biosciences Institute, Arkansas State University, Jonesboro, AR 72467-0639, USA
- Worcester Polytechnic Institute, Worcester, MA 01609, USA
| | - Argelia Lorence
- Arkansas Biosciences Institute, Arkansas State University, Jonesboro, AR 72467-0639, USA
| | - Pamela J. Weathers
- Arkansas Biosciences Institute, Arkansas State University, Jonesboro, AR 72467-0639, USA,
- Worcester Polytechnic Institute, Worcester, MA 01609, USA
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Abstract
Artemisinin the sesquiterpene endoperoxide lactone extracted from the herb Artemisia annua, remains the basis for the current preferred treatment against the malaria parasite Plasmodium falciparum. In addition, artemisinin and its derivatives show additional anti-parasite, anti-cancer, and anti-viral properties. Widespread use of this valuable secondary metabolite has been hampered by low production in vivo and high cost of chemical synthesis in vitro. Novel production methods are required to accommodate the ever-growing need for this important drug. Past work has focused on increasing production through traditional breeding approaches, with limited success, and on engineering cultured plants for high production in bioreactors. New research is focusing on heterologous expression systems for this unique biochemical pathway. Recently discovered genes, including a cytochrome P450 and its associated reductase, have been shown to catalyze multiple steps in the biochemical pathway leading to artemisinin. This has the potential to make a semi-synthetic approach to production both possible and cost effective. Artemisinin precursor production in engineered Saccharomyces cerevisiae is about two orders of magnitude higher than from field-grown A. annua. Efforts to increase flux through engineered pathways are on-going in both E. coli and S. cerevisiae through combinations of engineering precursor pathways and downstream optimization of gene expression. This review will compare older approaches to overproduction of this important drug, and then focus on the results from the newer approaches using heterologous expression systems and how they might meet the demands for treating malaria and other diseases.
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Arsenault PR. The role of the perfusionist. J Intraven Nurs 2000; 23:99-104. [PMID: 11988979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
During open heart procedures, the heart is stopped. The surgeon needs a blood-free, motionless work area. The heart-lung bypass machine provides circulation for the rest of the body during surgery. The perfusionist, as an active member of the surgical team, operates the heart-lung bypass machine. Historical development of the perfusionist's role and collaboration with other members of the healthcare team are discussed.
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