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Nadolnik LI, Niatsetskaya ZV, Basinsky VA, Vinogradov VV. Morphological and functional changes in rat thyroid gland after a year following chronic exposure to low and intermediate doses of γ-radiation. Int J Radiat Biol 2023; 100:343-352. [PMID: 37934053 DOI: 10.1080/09553002.2023.2280012] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 10/13/2023] [Indexed: 11/08/2023]
Abstract
INTRODUCTION Thyroid function depends on iodine uptake by the body as well as on exposure to various harmful environmental hazards (stress, ionizing radiation). AIM The aim of the work was to assess the effect of exposure to low and intermediate doses of external γ-radiation on the thyroid structure and function in young female rats at remote periods after radiation. MATERIALS AND METHODS Forty female rats were used to study remote effects of external γ-radiation exposure during 20 d (at daily doses of 0.1, 0.25 and 0.5 Gy) on the functional activity (levels of thyroid hormones, iodine metabolism) and the morphological structure of the rat thyroid) after 12 months following the radiation exposure. RESULTS An increase in thyroid mass and a decrease in total thyroid protein concentration along with a reduction of blood T3 and T4 was shown only in rat groups exposed to 0.25 and 0.5 Gy. Both the concentration of total iodine and its protein-bound fraction (1.2-1.4 fold, p < .01) and the protein-bound to total iodine ratio were decreased in the thyroids of all irradiated animals. The 0.1-Gy group showed elevated thyroperoxidase (TPO) activity along with increased catalase activity, which may indicate the activation of iodine oxidation by thyrocytes. Only the 0.5-Gy group demonstrated reduced urinary excretion of iodine (2.1 fold, p < .01).The reduction of thyroid function at radiation doses of 0.25 and 0.5 Gy was characterized by a microfollicular structure and the development of atrophic changes in the parenchyma, desquamation of thyroid epithelium and an increase in epithelium proliferation. The diameter of the thyrocyte nuclei was increased in rats exposed to 0.25 and 0.5 Gy, which indicates functional tension of thyrocytes. CONCLUSION Our research shows that after a year, the exposure to external γ-radiation of 0.1, 0.25 and 0.5-Gy caused changes in the structure and function of the rat thyroid which are manifested by the development of hypothyroiditis (0.5 Gy), 'subclinical' hypothyroiditis (0.25 Gy) and functional tension of thyrocytes. The mechanisms of thyroid dysfunction - impaired- uptake of iodine and its organification against the background of activation of free radical processes - suggest disturbances in the function of the sodium/iodide symporter (NIS), TPO and thyroglobulin synthesis. In contrast to the intermediate doses, the effects of the 0.1-Gy dose were mostly found at the remote periods compared to the earlier periods (180 days).
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Affiliation(s)
- Liliya I Nadolnik
- Institute of Biochemistry of Biologically Active Compounds of the National Academy of Sciences of Belarus, Grodno, Belarus
| | - Zoya V Niatsetskaya
- Institute of Biochemistry of Biologically Active Compounds of the National Academy of Sciences of Belarus, Grodno, Belarus
- Department of Pediatrics, Rutgers-Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | | | - Vladimir V Vinogradov
- Institute of Biochemistry of Biologically Active Compounds of the National Academy of Sciences of Belarus, Grodno, Belarus
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Sosunov SA, Niatsetskaya ZV, Stepanova AA, Galkin AS, Juliano CE, Ratner VI, Ten VS. Developmental window of vulnerability to white matter injury driven by sublethal intermittent hypoxemia. Pediatr Res 2022; 91:1383-1390. [PMID: 33947998 PMCID: PMC8566320 DOI: 10.1038/s41390-021-01555-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 04/09/2021] [Accepted: 04/12/2021] [Indexed: 02/03/2023]
Abstract
BACKGROUND In the developing brain, the death of immature oligodendrocytes (OLs) has been proposed to explain a developmental window for vulnerability to white matter injury (WMI). However, in neonatal mice, chronic sublethal intermittent hypoxia (IH) recapitulates the phenotype of diffuse WMI without affecting cellular viability. This work determines whether, in neonatal mice, a developmental window of WMI vulnerability exists in the absence of OLs lineage cellular death. METHODS Neonatal mice were exposed to cell-nonlethal early or late IH stress. The presence or absence of WMI phenotype in their adulthood was defined by the extent of sensorimotor deficit and diffuse cerebral hypomyelination. A separate cohort of mice was examined for markers of cellular degeneration and OLs maturation. RESULTS Compared to normoxic littermates, only mice exposed to early IH stress demonstrated arrested OLs maturation, diffuse cerebral hypomyelination, and sensorimotor deficit. No cellular death associated with IH was detected. CONCLUSIONS Neonatal sublethal IH recapitulates the phenotype of diffuse WMI only when IH stress coincides with the developmental stage of primary white matter myelination. This signifies a contribution of cell-nonlethal mechanisms in defining the developmental window of vulnerability to diffuse WMI. IMPACT The key message of our work is that the developmental window of vulnerability to the WMI driven by intermittent hypoxemia exists even in the absence of excessive OLs and other cells death. This is an important finding because the existence of the developmental window of vulnerability to WMI has been explained by a lethal-selective sensitivity of immature OLs to hypoxic and ischemic stress, which coincided with their differentiation. Thus, our study expands mechanistic explanation of a developmental window of sensitivity to WMI by showing the existence of cell-nonlethal pathways responsible for this biological phenomenon.
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Affiliation(s)
- Sergey A. Sosunov
- Department of Pediatrics, Division of Neonatology, Columbia University, New York, NY
| | - Zoya V. Niatsetskaya
- Department of Pediatrics, Division of Neonatology, Columbia University, New York, NY
| | - Anna A. Stepanova
- Department of Pediatrics, Division of Neonatology, Columbia University, New York, NY
| | - Alexander S. Galkin
- Department of Pediatrics, Division of Neonatology, Columbia University, New York, NY
| | - Courtney E. Juliano
- Department of Pediatrics, Division of Neonatology, Icahn Mount Sinai School of Medicine, New York, NY
| | - Veniamin I. Ratner
- Department of Pediatrics, Division of Neonatology, Icahn Mount Sinai School of Medicine, New York, NY
| | - Vadim S. Ten
- Department of Pediatrics, Division of Neonatology, Columbia University, New York, NY.,Corresponding author: Vadim S. Ten MD, PhD. , Address: 650 West 168 street, William Black Building, 4th floor, room 407, New York, NY, 10032, phone number: 212-342-0075
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Sosunov SA, Ameer X, Niatsetskaya ZV, Utkina-Sosunova I, Ratner VI, Ten VS. Isoflurane anesthesia initiated at the onset of reperfusion attenuates oxidative and hypoxic-ischemic brain injury. PLoS One 2015; 10:e0120456. [PMID: 25799166 PMCID: PMC4370491 DOI: 10.1371/journal.pone.0120456] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [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: 09/11/2014] [Accepted: 01/22/2015] [Indexed: 01/16/2023] Open
Abstract
This study demonstrates that in mice subjected to hypoxia-ischemia (HI) brain injury isoflurane anesthesia initiated upon reperfusion limits a release of mitochondrial oxidative radicals by inhibiting a recovery of complex-I dependent mitochondrial respiration. This significantly attenuates an oxidative stress and reduces the extent of HI brain injury. Neonatal mice were subjected to HI, and at the initiation of reperfusion were exposed to isoflurane with or without mechanical ventilation. At the end of HI and isoflurane exposure cerebral mitochondrial respiration, H2O2 emission rates were measured followed by an assessment of cerebral oxidative damage and infarct volumes. At 8 weeks after HI navigational memory and brain atrophy were assessed. In vitro, direct effect of isoflurane on mitochondrial H2O2 emission was compared to that of complex-I inhibitor, rotenone. Compared to controls, 15 minutes of isoflurane anesthesia inhibited recovery of the compex I-dependent mitochondrial respiration and decreased H2O2 production in mitochondria supported with succinate. This was associated with reduced oxidative brain injury, superior navigational memory and decreased cerebral atrophy compared to the vehicle-treated HI-mice. Extended isoflurane anesthesia was associated with sluggish recovery of cerebral blood flow (CBF) and the neuroprotection was lost. However, when isoflurane anesthesia was supported with mechanical ventilation the CBF recovery improved, the event associated with further reduction of infarct volume compared to HI-mice exposed to isoflurane without respiratory support. Thus, in neonatal mice brief isoflurane anesthesia initiated at the onset of reperfusion limits mitochondrial release of oxidative radicals and attenuates an oxidative stress. This novel mechanism contributes to neuroprotective action of isoflurane. The use of mechanical ventilation during isoflurane anesthesia counterbalances negative effect of isoflurane anesthesia on recovery of cerebral circulation which potentiates protection against reperfusion injury.
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Affiliation(s)
- Sergey A. Sosunov
- Department of Pediatrics, Division of Neonatology, Columbia University, New York, New York, United States of America
| | - Xavier Ameer
- Department of Pediatrics, Division of Neonatology, Columbia University, New York, New York, United States of America
| | - Zoya V. Niatsetskaya
- Department of Pediatrics, Division of Neonatology, Columbia University, New York, New York, United States of America
| | - Irina Utkina-Sosunova
- Department of Pediatrics, Division of Neonatology, Columbia University, New York, New York, United States of America
| | - Veniamin I. Ratner
- Department of Pediatrics, Division of Neonatology, Columbia University, New York, New York, United States of America
| | - Vadim S. Ten
- Department of Pediatrics, Division of Neonatology, Columbia University, New York, New York, United States of America
- * E-mail:
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Ratner V, Sosunov SA, Niatsetskaya ZV, Utkina-Sosunova IV, Ten VS. Mechanical ventilation causes pulmonary mitochondrial dysfunction and delayed alveolarization in neonatal mice. Am J Respir Cell Mol Biol 2014; 49:943-50. [PMID: 23980609 DOI: 10.1165/rcmb.2012-0172oc] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Hyperoxia inhibits pulmonary bioenergetics, causing delayed alveolarization in mice. We hypothesized that mechanical ventilation (MV) also causes a failure of bioenergetics to support alveolarization. To test this hypothesis, neonatal mice were ventilated with room air for 8 hours (prolonged) or for 2 hours (brief) with 15 μl/g (aggressive) tidal volume (Tv), or for 8 hours with 8 μl/g (gentle) Tv. After 24 hours or 10 days of recovery, lung mitochondria were examined for adenosine diphosphate (ADP)-phosphorylating respiration, using complex I (C-I)-dependent, complex II (C-II)-dependent, or cytochrome C oxidase (C-IV)-dependent substrates, ATP production rate, and the activity of C-I and C-II. A separate cohort of mice was exposed to 2,4-dinitrophenol (DNP), a known uncoupler of oxidative phosphorylation. At 10 days of recovery, pulmonary alveolarization and the expression of vascular endothelial growth factor (VEGF) were assessed. Sham-operated littermates were used as control mice. At 24 hours after aggressive MV, mitochondrial ATP production rates and the activity of C-I and C-II were significantly decreased compared with control mice. However, at 10 days of recovery, only mice exposed to prolonged-aggressive MV continued to exhibit significantly depressed mitochondrial respiration. This was associated with significantly poorer alveolarization and VEGF expression. In contrast, mice exposed to brief-aggressive or prolonged-gentle MV exhibited restored mitochondrial ADP-phosphorylation, normal alveolarization and pulmonary VEGF content. Exposure to DNP fully replicated the phenotype consistent with alveolar developmental arrest. Our data suggest that the failure of bioenergetics to support normal lung development caused by aggressive and prolonged ventilation should be considered a fundamental mechanism for the development of bronchopulmonary dysplasia in premature neonates.
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Affiliation(s)
- Veniamin Ratner
- 1 Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, New York
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Utkina-Sosunova IV, Niatsetskaya ZV, Sosunov SA, Ratner VI, Matsiukevich D, Ten VS. Nelfinavir inhibits intra-mitochondrial calcium influx and protects brain against hypoxic-ischemic injury in neonatal mice. PLoS One 2013; 8:e62448. [PMID: 23614049 PMCID: PMC3632564 DOI: 10.1371/journal.pone.0062448] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [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: 11/08/2012] [Accepted: 03/21/2013] [Indexed: 11/20/2022] Open
Abstract
Nelfinavir (NLF), an antiretroviral agent, preserves mitochondrial membranes integrity and protects mature brain against ischemic injury in rodents. Our study demonstrates that in neonatal mice NLF significantly limits mitochondrial calcium influx, the event associated with protection of the brain against hypoxic-ischemic insult (HI). Compared to the vehicle-treated mice, cerebral mitochondria from NLF-treated mice exhibited a significantly greater tolerance to the Ca2+-induced membrane permeabilization, greater ADP-phosphorylating activity and reduced cytochrome C release during reperfusion. Pre-treatment with NLF or Ruthenium red (RuR) significantly improved viability of murine hippocampal HT-22 cells, reduced Ca2+ content and preserved membrane potential (Ψm) in mitochondria following oxygen-glucose deprivation (OGD). Following histamine-stimulated Ca2+ release from endoplasmic reticulum, in contrast to the vehicle-treated cells, the cells treated with NLF or RuR also demonstrated reduced Ca2+ content in their mitochondria, the event associated with preserved Ψm. Because RuR inhibits mitochondrial Ca2+ uniporter, we tested whether the NLF acts via the mechanism similar to the RuR. However, in contrast to the RuR, in the experiment with direct interaction of these agents with mitochondria isolated from naïve mice, the NLF did not alter mitochondrial Ca2+ influx, and did not prevent Ca2+ induced collapse of the Ψm. These data strongly argues against interaction of NLF and mitochondrial Ca2+ uniporter. Although the exact mechanism remains unclear, our study is the first to show that NLF inhibits intramitochondrial Ca2+ flux and protects developing brain against HI-reperfusion injury. This novel action of NLF has important clinical implication, because it targets a fundamental mechanism of post-ischemic cell death: intramitochondrial Ca2+ overload → mitochondrial membrane permeabilization → secondary energy failure.
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Affiliation(s)
| | - Zoya V. Niatsetskaya
- Department of Pediatrics, Columbia University, New York, New York, United States of America
| | - Sergey A. Sosunov
- Department of Pediatrics, Columbia University, New York, New York, United States of America
| | - Veniamin I. Ratner
- Department of Pediatrics, Columbia University, New York, New York, United States of America
| | - Dzmitry Matsiukevich
- Department of Pediatrics, Columbia University, New York, New York, United States of America
| | - Vadim S. Ten
- Department of Pediatrics, Columbia University, New York, New York, United States of America
- * E-mail:
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McConoughey SJ, Basso M, Niatsetskaya ZV, Sleiman SF, Smirnova NA, Langley BC, Mahishi L, Cooper AJL, Antonyak MA, Cerione RA, Li B, Starkov A, Chaturvedi RK, Beal MF, Coppola G, Geschwind DH, Ryu H, Xia L, Iismaa SE, Pallos J, Pasternack R, Hils M, Fan J, Raymond LA, Marsh JL, Thompson LM, Ratan RR. Inhibition of transglutaminase 2 mitigates transcriptional dysregulation in models of Huntington disease. EMBO Mol Med 2011; 2:349-70. [PMID: 20665636 PMCID: PMC3068019 DOI: 10.1002/emmm.201000084] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Caused by a polyglutamine expansion in the huntingtin protein, Huntington's disease leads to striatal degeneration via the transcriptional dysregulation of a number of genes, including those involved in mitochondrial biogenesis. Here we show that transglutaminase 2, which is upregulated in HD, exacerbates transcriptional dysregulation by acting as a selective corepressor of nuclear genes; transglutaminase 2 interacts directly with histone H3 in the nucleus. In a cellular model of HD, transglutaminase inhibition de-repressed two established regulators of mitochondrial function, PGC-1α and cytochrome c and reversed susceptibility of human HD cells to the mitochondrial toxin, 3-nitroproprionic acid; however, protection mediated by transglutaminase inhibition was not associated with improved mitochondrial bioenergetics. A gene microarray analysis indicated that transglutaminase inhibition normalized expression of not only mitochondrial genes but also 40% of genes that are dysregulated in HD striatal neurons, including chaperone and histone genes. Moreover, transglutaminase inhibition attenuated degeneration in a Drosophila model of HD and protected mouse HD striatal neurons from excitotoxicity. Altogether these findings demonstrate that selective TG inhibition broadly corrects transcriptional dysregulation in HD and defines a novel HDAC-independent epigenetic strategy for treating neurodegeneration.
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McConoughey SJ, Niatsetskaya ZV, Pasternack R, Hils M, Ratan RR, Cooper AJL. A nonradioactive dot blot assay for transglutaminase activity. Anal Biochem 2009; 390:91-3. [PMID: 19306836 DOI: 10.1016/j.ab.2009.03.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2009] [Revised: 03/12/2009] [Accepted: 03/17/2009] [Indexed: 10/21/2022]
Abstract
Aberrant transglutaminase (TG) activity has been implicated in the pathology of numerous diseases, including Huntington's disease and Alzheimer's disease. To fully characterize the role of TGs in these disorders, it is important that simple quantifiable assays be made available. The most commonly used assay currently employed requires significant time and a radioactive substrate. The assay described here uses a biotinylated substrate in conjunction with a dot blot apparatus to eliminate the use of radioactive substrates and allows relative transglutaminase activity to be measured simultaneously with minimal sample preparation in a large number of samples containing purified enzyme, cell extracts, or tissue homogenates.
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Cooper AJL, Pinto JT, Krasnikov BF, Niatsetskaya ZV, Han Q, Li J, Vauzour D, Spencer JPE. Substrate specificity of human glutamine transaminase K as an aminotransferase and as a cysteine S-conjugate beta-lyase. Arch Biochem Biophys 2008; 474:72-81. [PMID: 18342615 PMCID: PMC2474740 DOI: 10.1016/j.abb.2008.02.038] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [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: 12/26/2007] [Revised: 02/14/2008] [Accepted: 02/24/2008] [Indexed: 11/16/2022]
Abstract
Rat kidney glutamine transaminase K (GTK) exhibits broad specificity both as an aminotransferase and as a cysteine S-conjugate beta-lyase. The beta-lyase reaction products are pyruvate, ammonium and a sulfhydryl-containing fragment. We show here that recombinant human GTK (rhGTK) also exhibits broad specificity both as an aminotransferase and as a cysteine S-conjugate beta-lyase. S-(1,1,2,2-Tetrafluoroethyl)-l-cysteine is an excellent aminotransferase and beta-lyase substrate of rhGTK. Moderate aminotransferase and beta-lyase activities occur with the chemopreventive agent Se-methyl-l-selenocysteine. l-3-(2-Naphthyl)alanine, l-3-(1-naphthyl)alanine, 5-S-l-cysteinyldopamine and 5-S-l-cysteinyl-l-DOPA are measurable aminotransferase substrates, indicating that the active site can accommodate large aromatic amino acids. The alpha-keto acids generated by transamination/l-amino acid oxidase activity of the two catechol cysteine S-conjugates are unstable. A slow rhGTK-catalyzed beta-elimination reaction, as measured by pyruvate formation, was demonstrated with 5-S-l-cysteinyldopamine, but not with 5-S-l-cysteinyl-l-DOPA. The importance of transamination, oxidation and beta-elimination reactions involving 5-S-l-cysteinyldopamine, 5-S-l-cysteinyl-l-DOPA and Se-methyl-l-selenocysteine in human tissues and their biological relevance are discussed.
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Affiliation(s)
- Arthur J L Cooper
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY, USA.
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Cooper AJL, Younis IR, Niatsetskaya ZV, Krasnikov BF, Pinto JT, Petros WP, Callery PS. Metabolism of the cysteine S-conjugate of busulfan involves a beta-lyase reaction. Drug Metab Dispos 2008; 36:1546-52. [PMID: 18474673 DOI: 10.1124/dmd.108.020768] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The present work documents the first example of an enzyme-catalyzed beta-elimination of a thioether from a sulfonium cysteine S-conjugate. beta-(S-Tetrahydrothiophenium)-L-alanine (THT-A) is the cysteine S-conjugate of busulfan. THT-A slowly undergoes a nonenzymatic beta-elimination reaction at pH 7.4 and 37 degrees C to yield tetrahydrothiophene, pyruvate, and ammonia. This reaction is accelerated by 1) rat liver, kidney, and brain homogenates, 2) isolated rat liver mitochondria, and 3) pyridoxal 5'-phosphate (PLP). A PLP-dependent enzyme in rat liver cytosol that catalyzes a beta-lyase reaction with THT-A was identified as cystathionine gamma-lyase. This unusual drug metabolism pathway represents an alternate route for intermediates in the mercapturate pathway.
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Affiliation(s)
- Arthur J L Cooper
- Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York, USA
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