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Malawsky DS, Dismuke T, Liu H, Castellino E, Brenman J, Dasgupta B, Tikunov A, Gershon TR. Chronic AMPK inactivation slows SHH medulloblastoma progression by inhibiting mTORC1 signaling and depleting tumor stem cells. iScience 2023; 26:108443. [PMID: 38094249 PMCID: PMC10716552 DOI: 10.1016/j.isci.2023.108443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 03/28/2023] [Accepted: 11/08/2023] [Indexed: 01/19/2024] Open
Abstract
We show that inactivating AMPK in a genetic medulloblastoma model depletes tumor stem cells and slows progression. In medulloblastoma, the most common malignant pediatric brain tumor, drug-resistant stem cells co-exist with transit-amplifying cells and terminally differentiated neuronal progeny. Prior studies show that Hk2-dependent glycolysis promotes medulloblastoma progression by suppressing neural differentiation. To determine how the metabolic regulator AMPK affects medulloblastoma growth and differentiation, we inactivated AMPK genetically in medulloblastomas. We bred conditional Prkaa1 and Prkaa2 deletions into medulloblastoma-prone SmoM2 mice and compared SmoM2-driven medulloblastomas with intact or inactivated AMPK. AMPK-inactivation increased event-free survival (EFS) and altered cellular heterogeneity, increasing differentiation and decreasing tumor stem cell populations. Surprisingly, AMPK-inactivation decreased mTORC1 activity and decreased Hk2 expression. Hk2 deletion similarly depleted medulloblastoma stem cells, implicating reduced glycolysis in the AMPK-inactivated phenotype. Our results show that AMPK inactivation disproportionately impairs medulloblastoma stem cell populations typically refractory to conventional therapies.
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Affiliation(s)
- Daniel Shiloh Malawsky
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Taylor Dismuke
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Hedi Liu
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Ethan Castellino
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Jay Brenman
- Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Biplab Dasgupta
- Division of Oncology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Andrey Tikunov
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
- Children’s Center for Neurosciences Research, Children’s Hospital of Atlanta, Emory University, Atlanta, GA 30322, USA
| | - Timothy R. Gershon
- Department of Neurology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
- Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA
- Children’s Center for Neurosciences Research, Children’s Hospital of Atlanta, Emory University, Atlanta, GA 30322, USA
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2
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Tikunov A, Bates D, Macdonald J, Gershon T. TMET-01. DISRUPTION OF THE SERINE-PRODUCING PATHWAYS SLOWS PROGRESSION OF THE SONIC HEDGEHOG-DRIVEN MEDULLOBLASTOMA. Neuro Oncol 2022. [PMCID: PMC9661216 DOI: 10.1093/neuonc/noac209.1006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Abstract
We have found that medulloblastoma metabolism is specialized to promote growth in the CNS and can be targeted for anti-tumor therapy. Prior studies show that serine is scarce in the CNS and that metastatic tumors require serine-producing enzymes to grow in the brain. We analyzed whether medulloblastoma, a primary brain tumor, showed similar serine dependency. We found that Sonic Hedgehog signaling, which induces proliferation in cerebellar granule neuron progenitors in normal development and medulloblastoma formation when hyperactivated, also induces PHGDH and SHMT1, which each catalyze key steps in different serine-production pathways. To define the functional role of PHGDH and SHMT1 in medulloblastomas, we bred mice genetically engineered to develop SHH medulloblastomas with mice carrying deletions of each of these genes. We found that mice with Phgdh-deleted medulloblastomas showed slower progression and longer survival times, compared to mice with Phgdh-intact medulloblastomas. Medulloblastomas with combined deletion of Phgdh and Shmt1 show even slower tumor progression. Stable-isotope flux analysis suggests that different serine-producing pathways compensate for the loss of individual serine-producing enzymes, providing a rationale for the greater anti-tumor effect of disrupting multiple serine-producing enzymes simultaneously. Our data show that serine-producing enzymes can be targeted as a novel approach to medulloblastoma therapy, and underscore the importance of targeting multiple serine-production pathways in complex metabolic interventions.
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Affiliation(s)
| | | | | | - Timothy Gershon
- University of North Carolina School of Medicine , Chapel Hill, NC , USA
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3
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Tikunov A, Rosen E, Babcock B, Weir S, Parnham S, Macdonald J. BIMG-18. ELEVATED CYSTATHIONINE IN MEDULLOBLASTOMA DEMONSTRATES TUMOR-SPECIFIC METHIONINE METABOLISM. Neurooncol Adv 2021. [PMCID: PMC7992236 DOI: 10.1093/noajnl/vdab024.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
We investigated tumor-specific metabolism medulloblastoma using a non-biased MS-imaging screen and identified a pattern of methionine flux that may present a therapeutic opportunity. We studied brain tumors that form in mice genetically engineered to develop Sonic Hedgehog (SHH)-driven medulloblastoma. We subjected sagittal sections including brain and medulloblastoma to MS-imaging, generating concentration maps for hundreds of metabolites MW 100–400. We then confirmed results by analyzing tumor, brain and blood by LC-MS/MS, high-resolution NMR and 2D NMR-TOCSY, and used immunohistochemistry to determine the cellular localization of implicated enzymes. MS imaging, accomplished by matrix-assisted laser desorption electrospray ionization (MALDESI), detected cystathionine at an order of magnitude higher concentration in medulloblastomas compared to adjacent brain. No other metabolite showed such a strong, tumor-specific localization. LC-MS/MS and NMR methods confirmed cystathionine elevation. As cystathionine is the product of homocysteine and serine, catalyzed by cystathionine beta-synthase (CBS), we investigated CBS expression by IHC. Consistent with prior studies, we found that only astrocytes expressed CBS, both in the normal brain and within the tumors. ScRNA-seq confirmed Cbs only in astrocytes, and showed tumor cells express methionine-metabolizing enzymes Mat2a, Dnmt1, Ancy and Mtr. Together, these findings show that tumor cells generate and export homocysteine, which astrocytes convert to cystathionine. Tumor cystathionine generation responded to changes in methionine- cycle metabolites. In vivo, systemic administration of homocysteine increased tumor cystathionine which decreased in response to systemic folate, the methyl donor for homocysteine methyltransferase. Cystathionine itself was inert in tumors as tumor cells cultured in up to 8 mM cystathionine showed no change in cell cycle progression. Our studies show that medulloblastomas utilize methionine and generate homocysteine, but avoid folate-dependent homocysteine-methionine recycling by exporting homocysteine for detoxification by local astrocytes. This model suggests that treatments that impose methionine scarcity, folate scarcity or CBS inhibition may produce anti-tumor effects in medulloblastoma.
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Affiliation(s)
| | | | | | - Seth Weir
- Timothy Gershon UNC, Chapel Hill, NC, USA
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4
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Hwang D, Dismuke T, Tikunov A, Rosen EP, Kagel JR, Ramsey JD, Lim C, Zamboni W, Kabanov AV, Gershon TR, Sokolsky-Papkov PhD M. Poly(2-oxazoline) nanoparticle delivery enhances the therapeutic potential of vismodegib for medulloblastoma by improving CNS pharmacokinetics and reducing systemic toxicity. Nanomedicine 2021; 32:102345. [PMID: 33259959 PMCID: PMC8160025 DOI: 10.1016/j.nano.2020.102345] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [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: 06/19/2020] [Revised: 10/16/2020] [Accepted: 11/20/2020] [Indexed: 10/22/2022]
Abstract
We report a nanoparticle formulation of the SHH-pathway inhibitor vismodegib that improves efficacy for medulloblastoma, while reducing toxicity. Limited blood-brain barrier (BBB) penetration and dose-limiting extitle/citraneural toxicities complicate systemic therapies for brain tumors. Vismodegib is FDA-approved for SHH-driven basal cell carcinoma, but implementation for medulloblastoma has been limited by inadequate efficacy and excessive bone toxicity. To address these issues through optimized drug delivery, we formulated vismodegib in polyoxazoline block copolymer micelles (POx-vismo). We then evaluated POx-vismo in transgenic mice that develop SHH-driven medulloblastomas with native vasculature and tumor microenvironment. POx-vismo improved CNS pharmacokinetics and reduced bone toxicity. Mechanistically, the nanoparticle carrier did not enter the CNS, and acted within the vascular compartment to improve drug delivery. Unlike conventional vismodegib, POx-vismo extended survival in medulloblastoma-bearing mice. Our results show the broad potential for non-targeted nanoparticle formulation to improve systemic brain tumor therapy, and specifically to improve vismodegib therapy for SHH-driven cancers.
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Affiliation(s)
- Duhyeong Hwang
- Center for Nanotechnology in Drug Delivery and Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, NC, USA
| | - Taylor Dismuke
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - Andrey Tikunov
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - Elias P Rosen
- Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina, United States
| | - John R Kagel
- Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina, United States
| | - Jacob D Ramsey
- Center for Nanotechnology in Drug Delivery and Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, NC, USA
| | - Chaemin Lim
- Center for Nanotechnology in Drug Delivery and Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, NC, USA
| | - William Zamboni
- Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina, United States
| | - Alexander V Kabanov
- Center for Nanotechnology in Drug Delivery and Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, NC, USA; Laboratory of Chemical Design of Bionanomaterials, Faculty of Chemistry, M.V. Lomonosov Moscow State University, Moscow, Russia
| | - Timothy R Gershon
- Department of Neurology, UNC School of Medicine, University of North Carolina, Chapel Hill, NC, USA; Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC, USA; Neuroscience Center, University of North Carolina, Chapel Hill, NC, USA.
| | - Marina Sokolsky-Papkov PhD
- Center for Nanotechnology in Drug Delivery and Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, NC, USA.
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Zhirakovskaia E, Tikunov A, Babkin I, Tikunova N. Complete genome sequences of the first parechoviruses A associated with sporadic pediatric acute gastroenteritis in Russia. Infection, Genetics and Evolution 2020; 80:104214. [DOI: 10.1016/j.meegid.2020.104214] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 12/24/2019] [Accepted: 01/28/2020] [Indexed: 01/12/2023]
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Bryant K, Peng S, Tikunov A, Pierobon M, Gunda V, Tomar G, Singh P, Petricoin E, Macdonald J, Tran N, Kimmelman A, Der C. Abstract 5492: Inhibition of ERK MAPK signaling increases pancreatic cancer dependency on autophagy. Cancer Res 2018. [DOI: 10.1158/1538-7445.am2018-5492] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Pancreatic ductal adenocarcinoma (PDAC) cell growth is dependent on altered biochemical and cellular activities that facilitate increased metabolic dependencies. We determined the role of mutationally activated KRAS, found in ~95% of PDAC, in supporting autophagy. Surprisingly, acute KRAS suppression, which blocks proliferation, was associated with increased rather than decreased autophagic flux. Similarly, KRAS transformation of immortalized human pancreatic epithelial cells showed decreased autophagic flux. Pharmacologic inhibition of ERK MAPK phenocopied the genetic silencing of KRAS and also increased autophagic flux. Addressing a mechanism for ERK suppression increased autophagy, we found increased AMPK activity, decreased mTOR activity, and increased expression of autophagic proteins. We speculated that increased autophagy may be a compensatory mechanism caused by the loss of KRAS- and ERK-dependent metabolic processes. To address this possibility, we performed RNA-seq analyses to monitor gene expression changes in response to ERK inhibition. We observed increased transcription of genes responsible for the metabolic processes of autophagy and β-oxidation, with concurrent decreased transcription of glycolysis and mitochondrial-associated genes. These changes were validated in metabolomic analyses following either genetic silencing of KRAS or ERK inhibition. Thus, the loss of ERK-driven metabolic processes may induce compensatory mechanisms to increase autophagy. We then addressed whether ERK inhibition increased PDAC dependence on autophagy. Supporting this possibility, we found that cotreatment with the autophagy inhibitor chloroquine synergistically enhanced ERK inhibitor mediated antiproliferative activity. Similarly, genetic or pharmacologic inhibition of specific regulators of autophagy also enhanced ERK inhibitor activity. We conclude that concurrent suppression of multiple metabolic processes, to block compensatory rebound activities, will be needed for effective PDAC treatment.
Citation Format: Kirsten Bryant, Sen Peng, Andrey Tikunov, Mariaelena Pierobon, Venugopal Gunda, Garima Tomar, Pankaj Singh, Emanuel Petricoin, Jeffrey Macdonald, Nhan Tran, Alec Kimmelman, Channing Der. Inhibition of ERK MAPK signaling increases pancreatic cancer dependency on autophagy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5492.
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Affiliation(s)
| | - Sen Peng
- 2Translational Genomics Research Institute, Phoenix, AZ
| | - Andrey Tikunov
- 3School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | | | - Venugopal Gunda
- 5Eppley Institute for Cancer Research, University of Nebraska, Omaha, NE
| | - Garima Tomar
- 1UNC Lineberger Comp. Cancer Ctr., Chapel Hill, NC
| | - Pankaj Singh
- 5Eppley Institute for Cancer Research, University of Nebraska, Omaha, NE
| | | | - Jeffrey Macdonald
- 3School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | | | - Alec Kimmelman
- 7Perlmutter Cancer Center, NYU Langone Medical Center, New York, NY
| | - Channing Der
- 1UNC Lineberger Comp. Cancer Ctr., Chapel Hill, NC
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Igolkina Y, Krasnova E, Rar V, Savelieva M, Epikhina T, Tikunov A, Khokhlova N, Provorova V, Tikunova N. Detection of causative agents of tick-borne rickettsioses in Western Siberia, Russia: identification of Rickettsia raoultii and Rickettsia sibirica DNA in clinical samples. Clin Microbiol Infect 2017; 24:199.e9-199.e12. [PMID: 28606645 DOI: 10.1016/j.cmi.2017.06.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [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: 03/23/2017] [Revised: 05/29/2017] [Accepted: 06/01/2017] [Indexed: 12/01/2022]
Abstract
OBJECTIVES The main causative agent of tick-borne rickettsioses in Siberia is considered to be Rickettsia sibirica; however, only a few cases have been genetically confirmed. Other pathogenic species of Rickettsia have been detected in ixodid ticks in Western Siberia. The aim of this study was to detect the aetiological agents of tick-borne rickettsioses in Western Siberia and compare their clinical manifestations. METHODS A total of 273 blood and 44 cerebrospinal fluid (CSF) samples from 273 patients hospitalized because of tick-transmitted infection in April-September 2016 were examined for the presence of Rickettsia spp., using nested PCR with subsequent sequencing. RESULTS DNA of Rickettsia spp. was found in samples from 10 patients. The gltA gene fragment sequence analysis revealed R. sibirica DNA in seven patients (blood samples) and Rickettsia raoultii DNA in three patients (two blood and one CSF sample). Most patients infected with R. sibirica showed typical clinical symptoms, including high-grade fever (38.9-39.5°С), myalgia, rash, eschar at the site of the tick bite, and elevated levels of serum aminotransferases. In contrast, patients infected with R. raoultii showed nonspecific symptoms with short-term fever (37.2-37.7°С); one patient had a short episode of meningeal syndrome. CONCLUSIONS We report the first finding of R. raoultii DNA in clinical samples from Russian patients. The clinical manifestations of this rickettsiosis were nonspecific and differed from those caused by R. sibirica.
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Affiliation(s)
- Y Igolkina
- Institute of Chemical Biology and Fundamental Medicine, SB RAS, Novosibirsk, Russian Federation.
| | - E Krasnova
- Novosibirsk State Medical University, Novosibirsk, Russian Federation; Novosibirsk Municipal Clinical Hospital of Infectious Diseases No. 1, Novosibirsk, Russian Federation
| | - V Rar
- Institute of Chemical Biology and Fundamental Medicine, SB RAS, Novosibirsk, Russian Federation
| | - M Savelieva
- Novosibirsk Municipal Clinical Hospital of Infectious Diseases No. 1, Novosibirsk, Russian Federation
| | - T Epikhina
- Institute of Chemical Biology and Fundamental Medicine, SB RAS, Novosibirsk, Russian Federation
| | - A Tikunov
- Institute of Chemical Biology and Fundamental Medicine, SB RAS, Novosibirsk, Russian Federation
| | - N Khokhlova
- Novosibirsk State Medical University, Novosibirsk, Russian Federation; Novosibirsk Municipal Clinical Hospital of Infectious Diseases No. 1, Novosibirsk, Russian Federation
| | - V Provorova
- Novosibirsk State Medical University, Novosibirsk, Russian Federation; Novosibirsk Municipal Clinical Hospital of Infectious Diseases No. 1, Novosibirsk, Russian Federation
| | - N Tikunova
- Institute of Chemical Biology and Fundamental Medicine, SB RAS, Novosibirsk, Russian Federation; Novosibirsk State University, Novosibirsk, Russian Federation
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Murphree CA, Dums JT, Jain SK, Zhao C, Young DY, Khoshnoodi N, Tikunov A, Macdonald J, Pilot G, Sederoff H. Amino Acids Are an Ineffective Fertilizer for Dunaliella spp. Growth. Front Plant Sci 2017; 8:847. [PMID: 28603530 PMCID: PMC5445130 DOI: 10.3389/fpls.2017.00847] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 05/08/2017] [Indexed: 06/01/2023]
Abstract
Autotrophic microalgae are a promising bioproducts platform. However, the fundamental requirements these organisms have for nitrogen fertilizer severely limit the impact and scale of their cultivation. As an alternative to inorganic fertilizers, we investigated the possibility of using amino acids from deconstructed biomass as a nitrogen source in the genus Dunaliella. We found that only four amino acids (glutamine, histidine, cysteine, and tryptophan) rescue Dunaliella spp. growth in nitrogen depleted media, and that supplementation of these amino acids altered the metabolic profile of Dunaliella cells. Our investigations revealed that histidine is transported across the cell membrane, and that glutamine and cysteine are not transported. Rather, glutamine, cysteine, and tryptophan are degraded in solution by a set of oxidative chemical reactions, releasing ammonium that in turn supports growth. Utilization of biomass-derived amino acids is therefore not a suitable option unless additional amino acid nitrogen uptake is enabled through genetic modifications of these algae.
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Affiliation(s)
- Colin A. Murphree
- Department of Plant and Microbial Biology, North Carolina State University, RaleighNC, United States
| | - Jacob T. Dums
- Department of Plant and Microbial Biology, North Carolina State University, RaleighNC, United States
| | - Siddharth K. Jain
- Department of Plant and Microbial Biology, North Carolina State University, RaleighNC, United States
| | - Chengsong Zhao
- Department of Plant Pathology, Physiology, and Weed Science, Virginia Polytechnic Institute and State University, BlacksburgVA, United States
| | - Danielle Y. Young
- Department of Plant and Microbial Biology, North Carolina State University, RaleighNC, United States
| | | | - Andrey Tikunov
- Department of Biomedical Engineering, University of North Carolina School of Medicine, Chapel HillNC, United States
| | - Jeffrey Macdonald
- Department of Biomedical Engineering, University of North Carolina School of Medicine, Chapel HillNC, United States
| | - Guillaume Pilot
- Department of Plant Pathology, Physiology, and Weed Science, Virginia Polytechnic Institute and State University, BlacksburgVA, United States
| | - Heike Sederoff
- Department of Plant and Microbial Biology, North Carolina State University, RaleighNC, United States
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Igolkina Y, Bondarenko E, Rar V, Epikhina T, Vysochina N, Pukhovskaya N, Tikunov A, Ivanov L, Golovljova I, Ivanov М, Tikunova N. Genetic variability of Rickettsia spp. in Ixodes persulcatus ticks from continental and island areas of the Russian Far East. Ticks Tick Borne Dis 2016; 7:1284-1289. [PMID: 27424272 DOI: 10.1016/j.ttbdis.2016.06.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [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: 11/05/2015] [Revised: 04/22/2016] [Accepted: 06/23/2016] [Indexed: 11/15/2022]
Abstract
Rickettsia spp. are intracellular Gram-negative bacteria transmitted by arthropods. Two potentially pathogenic rickettsiae, Candidatus Rickettsia tarasevichiae and Rickettsia helvetica, have been found in unfed adult Ixodes persulcatus ticks. The aim of this study was to assess the prevalence and genetic variability of Rickettsia spp. in I. persulcatus ticks collected from different locations in the Russian Far East. In total, 604 adult I. persulcatus ticks collected from four sites in the Khabarovsk Territory (continental area) and one site in Sakhalin Island were examined for the presence of Rickettsia spp. by real-time PCR. Nested PCR with species-specific primers and sequencing were used for genotyping of revealed rickettsiae. The overall prevalence of Rickettsia spp. in ticks collected in different sites varied from 67.9 to 90.7%. However, the proportion of different Rickettsia species observed in ticks from Sakhalin Island significantly differed from that in ticks from the Khabarovsk Territory. In Sakhalin Island, R. helvetica prevailed in examined ticks, while Candidatus R. tarasevichiae was predominant in the Khabarovsk Territory. For gltA and ompB gene fragments, the sequences obtained for Candidatus R. tarasevichiae from all studied sites were identical to each other and to the known sequences of this species. According to sequence analysis of gltA, оmpB and sca4 genes, R. helvetica isolates from Sakhalin Island and the Khabarovsk Territory were identical to each other, but they differed from R. helvetica from other regions and from those found in other tick species. For the first time, DNA of pathogenic Rickettsia heilongjiangensis was detected in I. persulcatus ticks in two sites from the Khabarovsk Territory. The gltA, ompA and оmpB gene sequences of R. heilongjiangensis were identical to or had solitary mismatches with the corresponding sequences of R. heilongjiangensis found in other tick species.
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Affiliation(s)
- Y Igolkina
- Institute of Chemical Biology and Fundamental Medicine, SB RAS, Novosibirsk, Russian Federation.
| | - E Bondarenko
- Join-stock company "Vector-Best", Novosibirsk, Russian Federation
| | - V Rar
- Institute of Chemical Biology and Fundamental Medicine, SB RAS, Novosibirsk, Russian Federation
| | - T Epikhina
- Institute of Chemical Biology and Fundamental Medicine, SB RAS, Novosibirsk, Russian Federation
| | - N Vysochina
- Khabarovsk Antiplague Station, Khabarovsk, Russian Federation
| | - N Pukhovskaya
- Khabarovsk Antiplague Station, Khabarovsk, Russian Federation
| | - A Tikunov
- Institute of Chemical Biology and Fundamental Medicine, SB RAS, Novosibirsk, Russian Federation
| | - L Ivanov
- Khabarovsk Antiplague Station, Khabarovsk, Russian Federation
| | - I Golovljova
- Institute of Chemical Biology and Fundamental Medicine, SB RAS, Novosibirsk, Russian Federation; Department of Virology, National Institute for Health Development, Estonia
| | - М Ivanov
- Join-stock company "Vector-Best", Novosibirsk, Russian Federation
| | - N Tikunova
- Institute of Chemical Biology and Fundamental Medicine, SB RAS, Novosibirsk, Russian Federation
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Tech K, Fish T, Crowther A, Tikunov A, Macdonald J, Gershon T. PM-06 * DIFFERENTIAL SPLICING OF PYRUVATE KINASE REGULATES PROGENITOR CELL CYCLE AND MEDULLOBLASTOMA TUMORIGENESIS. Neuro Oncol 2015. [DOI: 10.1093/neuonc/nov061.128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Egan T, Dong B, Tikunov A, Semelka C, Blackwell J, Simmons W, Kuan PF, Macdonald J. Effect of Ex-Vivo Lung Perfusion (EVLP) on Metabolomic Profile of Human Lungs. J Heart Lung Transplant 2013. [DOI: 10.1016/j.healun.2013.01.638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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Egan T, Dong B, Tikunov A, Semelka C, Kuan PF, Macdonald J. Metabolomic Profile of Rat Lung Tissue after Death: Effect of Delayed Post-Mortem O2-Ventilation. J Heart Lung Transplant 2013. [DOI: 10.1016/j.healun.2013.01.843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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Gershon TR, Crowther AJ, Tikunov A, Garcia I, Annis R, Yuan H, Miller CR, Macdonald J, Olson J, Deshmukh M. Hexokinase-2-mediated aerobic glycolysis is integral to cerebellar neurogenesis and pathogenesis of medulloblastoma. Cancer Metab 2013; 1:2. [PMID: 24280485 PMCID: PMC3782751 DOI: 10.1186/2049-3002-1-2] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Accepted: 08/09/2012] [Indexed: 01/06/2023] Open
Abstract
Background While aerobic glycolysis is linked to unconstrained proliferation in cancer, less is known about its physiological role. Why this metabolic program that promotes tumor growth is preserved in the genome has thus been unresolved. We tested the hypothesis that aerobic glycolysis derives from developmental processes that regulate rapid proliferation. Methods We performed an integrated analysis of metabolism and gene expression in cerebellar granule neuron progenitors (CGNPs) with and without Sonic Hedgehog (Shh), their endogenous mitogen. Because our analysis highlighted Hexokinase-2 (Hk2) as a key metabolic regulator induced by Shh, we studied the effect of conditional genetic Hk2 deletion in CGNP development. We then crossed Hk2 conditional knockout mice with transgenic SmoM2 mice that develop spontaneous medulloblastoma and determined changes in SmoM2-driven tumorigenesis. Results We show that Shh and phosphoinositide 3-kinase (PI3K) signaling combine to induce an Hk2-dependent glycolytic phenotype in CGNPs. This phenotype is recapitulated in medulloblastoma, a malignant tumor of CGNP origin. Importantly, cre-mediated ablation of Hk2 abrogated aerobic glycolysis, disrupting CGNP development and Smoothened-induced tumorigenesis. Comparing tumorigenesis in medulloblastoma-prone SmoM2 mice with and without functional Hk2, we demonstrate that loss of aerobic glycolysis reduces the aggressiveness of medulloblastoma, causing tumors to grow as indolent lesions and allowing long-term survival of tumor bearing mice. Conclusions Our investigations demonstrate that aerobic glycolysis in cancer derives from developmental mechanisms that persist in tumorigenesis. Moreover, we demonstrate in a primary tumor model the anti-cancer potential of blocking aerobic glycolysis by targeting Hk2. See commentary article:http://www.biomedcentral.com/1741-7007/11/3
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Affiliation(s)
- Timothy R Gershon
- Department of Neurology, University of North Carolina, Chapel Hill, NC, 27599, USA.
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Holmuhamedov EL, Czerny C, Lovelace G, Beeson CC, Baker T, Johnson CB, Pediaditakis P, Teplova VV, Tikunov A, MacDonald J, Lemasters JJ. Role of voltage-dependent anion channels of the mitochondrial outer membrane in regulation of cell metabolism. Biophysics (Nagoya-shi) 2010. [DOI: 10.1134/s0006350910050088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Kholmukhamedov EL, Czerny C, Lovelace G, Beeson KC, Baker T, Johnson CB, Pediaditakis P, Teplova VV, Tikunov A, MacDonald J, Lemasters JJ. [The role of the voltage-dependent anion channels in the outer membrane of mitochondria in the regulation of cellular metabolism]. Biofizika 2010; 55:822-833. [PMID: 21033348 PMCID: PMC4547860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The role of voltage-dependent anion channels (VDAC/porins) of the mitochondrial outer membrane in the regulation of cell metabolism is assessed using an experimental model of ethanol toxicity in cultured hepatocytes. It is demonstrated that ethanol inhibits the phosphorylating and the uncoupled mitochondrial respiration, decreases the accessibility of mitochondrial adenylate kinase in the intermembrane space, and suppresses ureagenic respiration in the cells. Treatment with digitonin at high concentrations (>80 μM)—which creates pores in the mitochondrial outer membrane, allowing bypass of closed VDAC—restores all the processes suppressed with ethanol. It is concluded that the effect of ethanol in hepatocytes leads to global loss of mitochondrial function because of closure of VDAC, which limits the free diffusion of metabolites into the intermembrane space. Our studies also reveal the role of VDAC in the regulation of liver-specific intracellular processes such as ureagenesis. The data obtained can be used in development of pharmaceuticals that would prevent VDAC closure in mitochondria of ethanol-oxidizing liver, thus protecting liver tissue from the hepatotoxic action of alcohol.
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Lee H, Tikunov A, Stoskopf MK, Macdonald JM. Applications of chemical shift imaging to marine sciences. Mar Drugs 2010; 8:2369-83. [PMID: 20948912 PMCID: PMC2953408 DOI: 10.3390/md8082369] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2010] [Revised: 07/21/2010] [Accepted: 08/13/2010] [Indexed: 11/24/2022] Open
Abstract
The successful applications of magnetic resonance imaging (MRI) in medicine are mostly due to the non-invasive and non-destructive nature of MRI techniques. Longitudinal studies of humans and animals are easily accomplished, taking advantage of the fact that MRI does not use harmful radiation that would be needed for plain film radiographic, computerized tomography (CT) or positron emission (PET) scans. Routine anatomic and functional studies using the strong signal from the most abundant magnetic nucleus, the proton, can also provide metabolic information when combined with in vivo magnetic resonance spectroscopy (MRS). MRS can be performed using either protons or hetero-nuclei (meaning any magnetic nuclei other than protons or ¹H) including carbon (¹³C) or phosphorus (³¹P). In vivo MR spectra can be obtained from single region of interest (ROI or voxel) or multiple ROIs simultaneously using the technique typically called chemical shift imaging (CSI). Here we report applications of CSI to marine samples and describe a technique to study in vivo glycine metabolism in oysters using ¹³C MRS 12 h after immersion in a sea water chamber dosed with [2-¹³C]-glycine. This is the first report of ¹³C CSI in a marine organism.
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Affiliation(s)
- Haakil Lee
- Joint Department of Biomedical Engineering NC State University and UNC Chapel Hill, Chapel Hill, NC 27599, USA
| | - Andrey Tikunov
- Joint Department of Biomedical Engineering NC State University and UNC Chapel Hill, Chapel Hill, NC 27599, USA
- Environmental Medicine Consortium, NC State University, 4700 Hillsborough St., Raleigh, NC 27606 USA; E-Mails: (A.T.); (M.K.S.); (J.M.M.)
| | - Michael K. Stoskopf
- Joint Department of Biomedical Engineering NC State University and UNC Chapel Hill, Chapel Hill, NC 27599, USA
- Environmental Medicine Consortium, NC State University, 4700 Hillsborough St., Raleigh, NC 27606 USA; E-Mails: (A.T.); (M.K.S.); (J.M.M.)
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 4700 Hillsborough St., Raleigh, NC, 27606, USA
| | - Jeffrey M. Macdonald
- Joint Department of Biomedical Engineering NC State University and UNC Chapel Hill, Chapel Hill, NC 27599, USA
- Environmental Medicine Consortium, NC State University, 4700 Hillsborough St., Raleigh, NC 27606 USA; E-Mails: (A.T.); (M.K.S.); (J.M.M.)
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Tikunov A, Johnson CB, Pediaditakis P, Markevich N, Macdonald JM, Lemasters JJ, Holmuhamedov E. Closure of VDAC causes oxidative stress and accelerates the Ca(2+)-induced mitochondrial permeability transition in rat liver mitochondria. Arch Biochem Biophys 2010; 495:174-81. [PMID: 20097153 DOI: 10.1016/j.abb.2010.01.008] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2009] [Accepted: 01/16/2010] [Indexed: 02/07/2023]
Abstract
The electron transport chain of mitochondria is a major source of reactive oxygen species (ROS), which play a critical role in augmenting the Ca(2+)-induced mitochondrial permeability transition (MPT). Mitochondrial release of superoxide anions (O(2)(-)) from the intermembrane space (IMS) to the cytosol is mediated by voltage dependent anion channels (VDAC) in the outer membrane. Here, we examined whether closure of VDAC increases intramitochondrial oxidative stress by blocking efflux of O(2)(-) from the IMS and sensitizing to the Ca(2+)-induced MPT. Treatment of isolated rat liver mitochondria with 5microM G3139, an 18-mer phosphorothioate blocker of VDAC, accelerated onset of the MPT by 6.8+/-1.4min within a range of 100-250microM Ca(2+). G3139-mediated acceleration of the MPT was reversed by 20microM butylated hydroxytoluene, a water soluble antioxidant. Pre-treatment of mitochondria with G3139 also increased accumulation of O(2)(-) in mitochondria, as monitored by dihydroethidium fluorescence, and permeabilization of the mitochondrial outer membrane with digitonin reversed the effect of G3139 on O(2)(-) accumulation. Mathematical modeling of generation and turnover of O(2)(-) within the IMS indicated that closure of VDAC produces a 1.55-fold increase in the steady-state level of mitochondrial O(2)(-). In conclusion, closure of VDAC appears to impede the efflux of superoxide anions from the IMS, resulting in an increased steady-state level of O(2)(-), which causes an internal oxidative stress and sensitizes mitochondria toward the Ca(2+)-induced MPT.
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Affiliation(s)
- Andrey Tikunov
- Department of Cell & Developmental Biology, University of North Carolina at Chapel Hill, 27599, USA
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Theruvath TP, Zhong Z, Pediaditakis P, Ramshesh VK, Currin RT, Tikunov A, Holmuhamedov E, Lemasters JJ. Minocycline and N-methyl-4-isoleucine cyclosporin (NIM811) mitigate storage/reperfusion injury after rat liver transplantation through suppression of the mitochondrial permeability transition. Hepatology 2008; 47:236-46. [PMID: 18023036 PMCID: PMC2656601 DOI: 10.1002/hep.21912] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
UNLABELLED Graft failure after liver transplantation may involve mitochondrial dysfunction. We examined whether prevention of mitochondrial injury would improve graft function. Orthotopic rat liver transplantation was performed after 18 hours' cold storage in University of Wisconsin solution and treatment with vehicle, minocycline, tetracycline, or N-methyl-4-isoleucine cyclosporin (NIM811) of explants and recipients. Serum alanine aminotransferase (ALT), necrosis, and apoptosis were assessed 6 hours after implantation. Mitochondrial polarization and cell viability were assessed by intravital microscopy. Respiration and the mitochondrial permeability transition (MPT) were assessed in isolated rat liver mitochondria. After transplantation with vehicle or tetracycline, ALT increased to 5242 U/L and 4373 U/L, respectively. Minocycline and NIM811 treatment decreased ALT to 2374 U/L and 2159 U/L, respectively (P < 0.01). Necrosis and terminal deoxynucleotidyl transferase-mediated nick-end labeling (TUNEL) also decreased from 21.4% and 21 cells/field, respectively, after vehicle to 10.1% and 6 cells/field after minocycline and to 8.7% and 5.2 cells/field after NIM811 (P < 0.05). Additionally, minocycline decreased caspase-3 activity in graft homogenates (P < 0.05). Long-term graft survival was 27% and 33%, respectively, after vehicle and tetracycline treatment, which increased to 60% and 70% after minocycline and NIM811 (P < 0.05). In isolated mitochondria, minocycline and NIM811 but not tetracycline blocked the MPT. Minocycline blocked the MPT by decreasing mitochondrial Ca(2+) uptake, whereas NIM811 blocks by interaction with cyclophilin D. Intravital microscopy showed that minocycline and NIM811 preserved mitochondrial polarization and cell viability after transplantation (P < 0.05). CONCLUSION Minocycline and NIM811 attenuated graft injury after rat liver transplantation and improved graft survival. Minocycline and/or NIM811 might be useful clinically in hepatic surgery and transplantation.
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Affiliation(s)
- Tom P. Theruvath
- Center for Cell Death, Injury and Regeneration, Medical University of South Carolina, Charleston, SC,Department of Pharmaceutical Sciences, Medical University of South Carolina, Charleston, SC
| | - Zhi Zhong
- Center for Cell Death, Injury and Regeneration, Medical University of South Carolina, Charleston, SC,Department of Pharmaceutical Sciences, Medical University of South Carolina, Charleston, SC
| | - Peter Pediaditakis
- Department of Pharmacology, University of North Carolina, Chapel Hill, NC
| | - Venkat K. Ramshesh
- Center for Cell Death, Injury and Regeneration, Medical University of South Carolina, Charleston, SC,Department of Pharmaceutical Sciences, Medical University of South Carolina, Charleston, SC
| | - Robert T. Currin
- Department of Cell & Developmental Biology, University of North Carolina, Chapel Hill, NC
| | - Andrey Tikunov
- Department of Cell & Developmental Biology, University of North Carolina, Chapel Hill, NC
| | - Ekhson Holmuhamedov
- Department of Cell & Developmental Biology, University of North Carolina, Chapel Hill, NC
| | - John J. Lemasters
- Center for Cell Death, Injury and Regeneration, Medical University of South Carolina, Charleston, SC,Department of Pharmaceutical Sciences, Medical University of South Carolina, Charleston, SC,Department of Biochemistry & Molecular Biology, Medical University of South Carolina, Charleston, SC
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