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Pagano P, Pagano A, Paternolli S, Balestrazzi A, Macovei A. Integrative Transcriptomics Data Mining to Explore the Functions of TDP1α and TDP1β Genes in the Arabidopsis thaliana Model Plant. Genes (Basel) 2023; 14:genes14040884. [PMID: 37107642 PMCID: PMC10137840 DOI: 10.3390/genes14040884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 04/07/2023] [Accepted: 04/07/2023] [Indexed: 04/29/2023] Open
Abstract
The tyrosyl-DNA phosphodiesterase 1 (TDP1) enzyme hydrolyzes the phosphodiester bond between a tyrosine residue and the 3'-phosphate of DNA in the DNA-topoisomerase I (TopI) complex, being involved in different DNA repair pathways. A small TDP1 gene subfamily is present in plants, where TDP1α has been linked to genome stability maintenance, while TDP1β has unknown functions. This work aimed to comparatively investigate the function of the TDP1 genes by taking advantage of the rich transcriptomics databases available for the Arabidopsis thaliana model plant. A data mining approach was carried out to collect information regarding gene expression in different tissues, genetic backgrounds, and stress conditions, using platforms where RNA-seq and microarray data are deposited. The gathered data allowed us to distinguish between common and divergent functions of the two genes. Namely, TDP1β seems to be involved in root development and associated with gibberellin and brassinosteroid phytohormones, whereas TDP1α is more responsive to light and abscisic acid. During stress conditions, both genes are highly responsive to biotic and abiotic treatments in a time- and stress-dependent manner. Data validation using gamma-ray treatments applied to Arabidopsis seedlings indicated the accumulation of DNA damage and extensive cell death associated with the observed changes in the TDP1 genes expression profiles.
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Affiliation(s)
- Paola Pagano
- Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, 27100 Pavia, Italy
| | - Andrea Pagano
- Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, 27100 Pavia, Italy
| | - Stefano Paternolli
- Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, 27100 Pavia, Italy
| | - Alma Balestrazzi
- Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, 27100 Pavia, Italy
| | - Anca Macovei
- Department of Biology and Biotechnology "L. Spallanzani", University of Pavia, 27100 Pavia, Italy
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Chen SY, Beretta M, Alexopoulos SJ, Shah DP, Olzomer EM, Hargett SR, Childress ES, Salamoun JM, Aleksovska I, Roseblade A, Cranfield C, Rawling T, Quinlan KGR, Morris MJ, Tucker SP, Santos WL, Hoehn KL. Mitochondrial uncoupler SHC517 reverses obesity in mice without affecting food intake. Metabolism 2021; 117:154724. [PMID: 33548253 DOI: 10.1016/j.metabol.2021.154724] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 01/27/2021] [Accepted: 02/01/2021] [Indexed: 12/13/2022]
Abstract
AIMS Mitochondrial uncouplers decrease caloric efficiency and have potential therapeutic benefits for the treatment of obesity and related metabolic disorders. Herein we investigate the metabolic and physiologic effects of a recently identified small molecule mitochondrial uncoupler named SHC517 in a mouse model of diet-induced obesity. METHODS SHC517 was administered as an admixture in food. The effect of SHC517 on in vivo energy expenditure and respiratory quotient was determined by indirect calorimetry. A dose-finding obesity prevention study was performed by starting SHC517 treatment concomitant with high fat diet for a period of 12 days. An obesity reversal study was performed by feeding mice western diet for 4 weeks prior to SHC517 treatment for 7 weeks. Biochemical assays were used to determine changes in glucose, insulin, triglycerides, and cholesterol. SHC517 concentrations were determined by mass spectrometry. RESULTS SHC517 increased lipid oxidation without affecting body temperature. SHC517 prevented diet-induced obesity when administered at 0.05% and 0.1% w/w in high fat diet and reversed established obesity when tested at the 0.05% dose. In the obesity reversal model, SHC517 restored adiposity to levels similar to chow-fed control mice without affecting food intake or lean body mass. SHC517 improved glucose tolerance and fasting glucose levels when administered in both the obesity prevention and obesity reversal modes. CONCLUSIONS SHC517 is a mitochondrial uncoupler with potent anti-obesity and insulin sensitizing effects in mice. SHC517 reversed obesity without altering food intake or compromising lean mass, effects that are highly sought-after in anti-obesity therapeutics.
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Affiliation(s)
- Sing-Young Chen
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Martina Beretta
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Stephanie J Alexopoulos
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Divya P Shah
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Ellen M Olzomer
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Stefan R Hargett
- Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA
| | - Elizabeth S Childress
- Department of Chemistry and Virginia Tech Centre for Drug Discovery, Virginia Tech, Blacksburg, VA 24061, USA
| | - Joseph M Salamoun
- Department of Chemistry and Virginia Tech Centre for Drug Discovery, Virginia Tech, Blacksburg, VA 24061, USA
| | - Isabella Aleksovska
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Ariane Roseblade
- School of Mathematical and Physical Sciences, University of Technology, Sydney, NSW 2007, Australia
| | - Charles Cranfield
- School of Life Sciences, University of Technology, Sydney, NSW 2007, Australia
| | - Tristan Rawling
- School of Mathematical and Physical Sciences, University of Technology, Sydney, NSW 2007, Australia
| | - Kate G R Quinlan
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Margaret J Morris
- School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Simon P Tucker
- Continuum Biosciences Pty Ltd., Sydney, NSW, 2035, Australia
| | - Webster L Santos
- Department of Chemistry and Virginia Tech Centre for Drug Discovery, Virginia Tech, Blacksburg, VA 24061, USA; Continuum Biosciences Pty Ltd., Sydney, NSW, 2035, Australia.
| | - Kyle L Hoehn
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia; Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA.; Continuum Biosciences Pty Ltd., Sydney, NSW, 2035, Australia.
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Salamoun JM, Garcia CJ, Hargett SR, Murray JH, Chen SY, Beretta M, Alexopoulos SJ, Shah DP, Olzomer EM, Tucker SP, Hoehn KL, Santos WL. 6-Amino[1,2,5]oxadiazolo[3,4- b]pyrazin-5-ol Derivatives as Efficacious Mitochondrial Uncouplers in STAM Mouse Model of Nonalcoholic Steatohepatitis. J Med Chem 2020; 63:6203-6224. [PMID: 32392051 PMCID: PMC11042500 DOI: 10.1021/acs.jmedchem.0c00542] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Small molecule mitochondrial uncouplers have recently garnered great interest for their potential in treating nonalcoholic steatohepatitis (NASH). In this study, we report the structure-activity relationship profiling of a 6-amino[1,2,5]oxadiazolo[3,4-b]pyrazin-5-ol core, which utilizes the hydroxy moiety as the proton transporter across the mitochondrial inner membrane. We demonstrate that a wide array of substituents is tolerated with this novel scaffold that increased cellular metabolic rates in vitro using changes in oxygen consumption rate as a readout. In particular, compound SHS4121705 (12i) displayed an EC50 of 4.3 μM in L6 myoblast cells and excellent oral bioavailability and liver exposure in mice. In the STAM mouse model of NASH, administration of 12i at 25 mg kg-1 day-1 lowered liver triglyceride levels and improved liver markers such as alanine aminotransferase, NAFLD activity score, and fibrosis. Importantly, no changes in body temperature or food intake were observed. As potential treatment of NASH, mitochondrial uncouplers show promise for future development.
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Affiliation(s)
- Joseph M Salamoun
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Christopher J Garcia
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Stefan R Hargett
- Departments of Pharmacology and Medicine, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Jacob H Murray
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Sing-Young Chen
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW 2033, Australia
| | - Martina Beretta
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW 2033, Australia
| | - Stephanie J Alexopoulos
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW 2033, Australia
| | - Divya P Shah
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW 2033, Australia
| | - Ellen M Olzomer
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW 2033, Australia
| | - Simon P Tucker
- Continuum Biosciences, Pty Ltd., Sydney 2035, Australia
- Continuum Biosciences Inc., Boston, Massachusetts 02116, United States
| | - Kyle L Hoehn
- Departments of Pharmacology and Medicine, University of Virginia, Charlottesville, Virginia 22908, United States
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW 2033, Australia
| | - Webster L Santos
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
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Anilinopyrazines as potential mitochondrial uncouplers. Bioorg Med Chem Lett 2020; 30:127057. [DOI: 10.1016/j.bmcl.2020.127057] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 02/16/2020] [Accepted: 02/20/2020] [Indexed: 12/18/2022]
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Childress ES, Salamoun JM, Hargett SR, Alexopoulos SJ, Chen SY, Shah DP, Santiago-Rivera J, Garcia CJ, Dai Y, Tucker SP, Hoehn KL, Santos WL. [1,2,5]Oxadiazolo[3,4- b]pyrazine-5,6-diamine Derivatives as Mitochondrial Uncouplers for the Potential Treatment of Nonalcoholic Steatohepatitis. J Med Chem 2020; 63:2511-2526. [PMID: 32017849 DOI: 10.1021/acs.jmedchem.9b01440] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Small molecule mitochondrial uncouplers are emerging as a new class of molecules for the treatment of nonalcoholic steatohepatitis. We utilized BAM15, a potent protonophore that uncouples the mitochondria without depolarizing the plasma membrane, as a lead compound for structure-activity profiling. Using oxygen consumption rate as an assay for determining uncoupling activity, changes on the 5- and 6-position of the oxadiazolopyrazine core were introduced. Our studies suggest that unsymmetrical aniline derivatives bearing electron withdrawing groups are preferred compared to the symmetrical counterparts. In addition, alkyl substituents are not tolerated, and the N-H proton of the aniline ring is responsible for the protonophore activity. In particular, compound 10b had an EC50 value of 190 nM in L6 myoblast cells. In an in vivo model of NASH, 10b decreased liver triglyceride levels and showed improvement in fibrosis, inflammation, and plasma ALT. Taken together, our studies indicate that mitochondrial uncouplers have potential for the treatment of NASH.
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Affiliation(s)
- Elizabeth S Childress
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Joseph M Salamoun
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Stefan R Hargett
- Departments of Pharmacology and Medicine, University of Virginia, Charlottesville, Virginia 22908, United States
| | - Stephanie J Alexopoulos
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW 2033, Australia
| | - Sing-Young Chen
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW 2033, Australia
| | - Divya P Shah
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW 2033, Australia
| | - José Santiago-Rivera
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Christopher J Garcia
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Yumin Dai
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Simon P Tucker
- Continuum Biosciences, Pty Ltd., 2035 Sydney, Australia.,Continuum Biosciences Inc., Boston, Massachusetts 02116, United States
| | - Kyle L Hoehn
- Departments of Pharmacology and Medicine, University of Virginia, Charlottesville, Virginia 22908, United States.,School of Biotechnology and Biomolecular Sciences, University of New South Wales, Kensington, NSW 2033, Australia
| | - Webster L Santos
- Department of Chemistry and Virginia Tech Center for Drug Discovery, Virginia Tech, Blacksburg, Virginia 24061, United States
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Electrogenic plasma membrane H+-ATPase activity using voltage sensitive dyes. J Bioenerg Biomembr 2010; 42:387-93. [PMID: 20734224 DOI: 10.1007/s10863-010-9306-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Accepted: 07/28/2010] [Indexed: 10/19/2022]
Abstract
Fast responding voltage sensitive dyes, RH421 and di-4-ASPBS, were used to study the electrogenic properties of plant plasma membrane proton pumps on sealed plasma membrane vesicles extracted by two-phase partitioning from Beta vulgaris and Avena sativa cv Swan root material. Fluorescence spectroscopy in the presence of the dye RH421 (10.8 nM) was sufficiently sensitive to detect electrogenic activity of the extracted plant vesicles. The dye detection system could detect inhibition of electrogenic activity of vesicles by vanadate (75 μM) and stimulation by nigericin (0.5 μM). The newly developed dye di-4-ASPBS was less sensitive to detecting the electrogenic proton pump activity. This study represents an important innovation in plant biophysics as this class of fast responding voltage sensitive dyes have never to our knowledge been used to study electrogenic proton pump activity derived from plant membranes and represents a novel approach for carrying out such studies.
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Kent RA, Caux PY. Sublethal effects of the insecticide fenitrothion on freshwater phytopiankton. ACTA ACUST UNITED AC 1995. [DOI: 10.1139/b95-006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effects of the insecticide fenitrothion (O,O-dimethyl-O-(3-methyl-4-nitrophenyl)phosphorothioate) were investigated on the unicellular phytoplankton Ankistrodesmus falcatus, Chlamydomonas reinhardtii, Chlamydomonas segnis, Chlorella pyrenoidosa, Navicula sp., Scenedesmus obliquus, Selenastrum capricornutum, and Staurastrum sp. at concentrations of 0.1, 1.0, and 10 mg∙L−1. Following a 24-h exposure, total lipids, fatty acid profiles, and bioaccumulation of fenitrothion into algal cells were determined for the above species. Total lipids may play an important role in determining sensitivity of phytoplankton to fenitrothion stress over 96-h exposures. A saturation occurred in A. falcatus membranes represented by the 5.4 and 4.3% increases in palmitic (16:0) and oleic (18:1) acids, respectively, and 1.8 and 7.6% decreases in linoleic (18:2) and linolenic (18:3) acids, respectively. This resulted in a shift from a profile dominated by linolenic (18:3) acid to one dominated by the more saturated oleic (18:1) acid. Bioconcentration factors (BCF), or the ratio of the total radiocarbon associated with algae, calculated for viable Chlamydomonas reinhardtii and Chlamydomonas segnis cells were 293 and 124, respectively. BCFs for dead cells were 1261 and 1025 for the same species, respectively. These investigations showed differential insecticide bioaccumulation between species. This bioaccumulation was shown to be correlated with the total lipid content of algal cells. Key words: algae, fatty acids, fenitrothion, lipids, pesticide.
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Jackson PC, Pfeffer PE, Gerasimowicz WV. Use of P NMR to Assess Effects of DNP on ATP Levels in Vivo in Barley Roots. PLANT PHYSIOLOGY 1986; 81:1130-3. [PMID: 16664955 PMCID: PMC1075497 DOI: 10.1104/pp.81.4.1130] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Previous work has shown that undissociated 2,4-dinitrophenol (DNP) both increases the permeability of roots to ions and alters the membrane lipids of barley roots. Anionic DNP is the main entrant form but has no effect on permeability or on the membrane lipids. The amount of anionic DNP taken up by the roots is sufficient, that were it in free solution in the cytoplasm, the DNP would uncouple oxidative phosphorylation, and thereby inhibit ATP synthesis. The present work was undertaken to assess whether DNP alters ATP levels when it is taken up by barley roots. (31)P nuclear magnetic resonance spectra were used to monitor, in vivo, levels of ATP, cytoplasmic phosphate, vacuolar phosphate, and other phosphate compounds in barley roots in the presence of 10 micromolar DNP at pH 5 and pH 7. The spectra indicate that no change in the level of ATP or the cytoplasmic pH occurred in the roots in the presence of DNP for as long as 20 hours. Thus, the effects of undissociated DNP are effects directly on the root membranes and do not involve inhibition of ATP synthesis. Furthermore, the results explain why anionic DNP has no effect on ion uptake and accumulation.
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Affiliation(s)
- P C Jackson
- United States Department of Agriculture, Agricultural Research Service, Plant Physiology Institute, Beltsville Agricultural Research Center, Beltsville, Maryland 20705
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Jackson PC, St John JB. Anesthetics alter the lipid composition of barley-root membranes. PLANTA 1984; 162:415-421. [PMID: 24253222 DOI: 10.1007/bf00393453] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/1983] [Accepted: 05/16/1984] [Indexed: 06/02/2023]
Abstract
The question of whether membrane expansion, which is caused by anesthetics in animal systems, alters the lipid composition of plant cell membranes was investigated. We have measured the effects of several anesthetics on the relative amounts of the principal fatty acids from the polar lipids of barley (Hordeum vulgare L.) root membranes. Procaine, dibucaine, tetracaine, chloroform and, to a lesser degree, methanol increased the proportions of palmitic, stearic and oleic acids and decreased the proportions of linoleic and linolenic acids. Ethanol had no significant effect. Total amounts of the fatty acids from the polar lipids of roots in procaine solution decreased markedly so that all of the acids decreased in amount. The anesthetic was effective as soon as the roots were introduced to the solution and the changes progressed at constant rates for 6 h. Only the polar membrane lipids were altered; other lipids were not affected. Increased hydrostatic pressure of about 1.0 MPa largely prevented the anesthetic effects, including the decrease in the total amounts of the fatty acids. Hydrostatic pressure as high as 2 MPa had no effect per se on the membrane lipid composition. These results indicate that anesthetics cause expansion of the root membranes which results in the lipid changes. That a compositional change in the membrane lipids involves a conformational change such as expansion is an indication of the nature of the link between changes in the membrane lipids and changes in function of areas where hydrophilic ions permeate.
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Affiliation(s)
- P C Jackson
- Agricultural Research Service, U.S. Department of Agriculture, 20705, Beltsville, MD, USA
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