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1.
Mol Med ; 29(1): 18, 2023 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-36721084

RESUMO

Triosephosphate isomerase (TPI) is best known as a glycolytic enzyme that interconverts the 3-carbon sugars dihydroxyacetone phosphate (DHAP) and glyceraldehyde-3-phosphate (G3P). TPI is an essential enzyme that is required for the catabolism of DHAP and a net yield of ATP from anaerobic glucose metabolism. Loss of TPI function results in the recessive disease TPI Deficiency (TPI Df). Recently, numerous lines of evidence suggest the TPI protein has other functions beyond glycolysis, a phenomenon known as moonlighting or gene sharing. Here we review the numerous functions ascribed to TPI, including recent findings of a nuclear role of TPI implicated in cancer pathogenesis and chemotherapy resistance.


Assuntos
Anemia Hemolítica Congênita não Esferocítica , Erros Inatos do Metabolismo dos Carboidratos , Humanos , Triose-Fosfato Isomerase/genética , Núcleo Celular , Glucose
2.
J Manipulative Physiol Ther ; 45(2): 144-152, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35753885

RESUMO

OBJECTIVE: The purpose of this study was to assess whether beliefs about the origin of the popping sound and the effects of thrust manipulation (TM) were in agreement with current scientific evidence and whether a practitioner's explanation could influence patient beliefs of theoretical mechanisms. METHODS: A cross-sectional online survey was conducted in Italy from January 7, 2019 to April 20, 2019. The questionnaire was sent to 900 Italian adults through online recruitment, including people with and without a history of manipulation, such as given by physiotherapists, chiropractors, osteopaths, and manual medicine physicians to manage musculoskeletal disorders. The questionnaire consisted of 11 multiple-choice questions and could be completed within 15 weeks. The Likert scale was used to investigate participants' attitudes. Sex and previous experience of TM variables were evaluated using a Student's t-test; a 1-way F analysis of variance test was performed to evaluate age, educational qualification, and the professional who performed the TM. RESULTS: We retrieved 478 questionnaires, including 175 participants with no TM history and 303 with TM history. There were 31% of participants (n = 94) with a history of TM who reported they did not receive explanations regarding manipulation. The participants' beliefs mostly disagreed with the current hypotheses provided by the scientific literature on the theoretical mechanisms of popping sound (tribonucleation and cavitation). There were 9.9% (n = 30) of participants who answered "realignment of bone positional fault" to explain the mechanism behind TM. There was a high degree of agreement with the belief that the popping sound should be present for a successful TM (respectively, 2.8 standard deviation [SD; 1.2] and 2.6 SD [1.2] for TM+ and TM- participants). No statistically significant differences were found between participants with and without a history of TM. CONCLUSION: The participants in this study reported a belief that popping was related to effectiveness of TM. A high percentage of this sample had beliefs about TM mechanisms for the audible popping sound that were inconsistent with current literature. Beliefs were similar between groups, suggesting that instructions given by TM practitioners did not seem to be an influence on these patients' beliefs.


Assuntos
Quiroprática , Médicos Osteopáticos , Adulto , Estudos Transversais , Humanos , Som , Inquéritos e Questionários
3.
Neurobiol Dis ; 152: 105299, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33600953

RESUMO

Triosephosphate isomerase (TPI) deficiency (Df) is a rare recessive metabolic disorder that manifests as hemolytic anemia, locomotor impairment, and progressive neurodegeneration. Research suggests that TPI Df mutations, including the "common" TPIE105Dmutation, result in reduced TPI protein stability that appears to underlie disease pathogenesis. Drosophila with the recessive TPIsugarkill allele (a.k.a. sgk or M81T) exhibit progressive locomotor impairment, neuromuscular impairment and reduced longevity, modeling the human disorder. TPIsugarkill produces a functional protein that is degraded by the proteasome. Molecular chaperones, such as Hsp70 and Hsp90, have been shown to contribute to the regulation of TPIsugarkill degradation. In addition, stabilizing the mutant protein through chaperone modulation results in improved TPI deficiency phenotypes. To identify additional regulators of TPIsugarkill degradation, we performed a genome-wide RNAi screen that targeted known and predicted quality control proteins in the cell to identify novel factors that modulate TPIsugarkill turnover. Of the 430 proteins screened, 25 regulators of TPIsugarkill were identified. Interestingly, 10 proteins identified were novel, previously undescribed Drosophila proteins. Proteins involved in co-translational protein quality control and ribosome function were also isolated in the screen, suggesting that TPIsugarkill may undergo co-translational selection for polyubiquitination and proteasomal degradation as a nascent polypeptide. The proteins identified in this study may reveal novel pathways for the degradation of a functional, cytosolic protein by the ubiquitin proteasome system and define therapeutic pathways for TPI Df and other biomedically important diseases.


Assuntos
Anemia Hemolítica Congênita não Esferocítica/metabolismo , Erros Inatos do Metabolismo dos Carboidratos/metabolismo , Proteínas de Drosophila/metabolismo , Triose-Fosfato Isomerase/deficiência , Triose-Fosfato Isomerase/metabolismo , Animais , Modelos Animais de Doenças , Drosophila melanogaster
4.
J Am Chem Soc ; 142(20): 9285-9301, 2020 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-32395989

RESUMO

Voltage sensitive fluorescent dyes (VSDs) are important tools for probing signal transduction in neurons and other excitable cells. The impact of these highly lipophilic sensors has, however, been limited due to the lack of cell-specific targeting methods in brain tissue or living animals. We address this key challenge by introducing a nongenetic molecular platform for cell- and molecule-specific targeting of synthetic VSDs in the brain. We employ a dextran polymer particle to overcome the inherent lipophilicity of VSDs by dynamic encapsulation and high-affinity ligands to target the construct to specific neuronal cells utilizing only native components of the neurotransmission machinery at physiological expression levels. Dichloropane, a monoamine transporter ligand, enables targeting of dense dopaminergic axons in the mouse striatum and sparse noradrenergic axons in the mouse cortex in acute brain slices. PFQX in conjunction with ligand-directed acyl imidazole chemistry enables covalent labeling of AMPA-type glutamate receptors in the same brain regions. Probe variants bearing either a classical electrochromic ANEP dye or state-of-the-art VoltageFluor-type dye respond to membrane potential changes in a similar manner to the parent dyes, as shown by whole-cell patch recording. We demonstrate the feasibility of optical voltage recording with our probes in brain tissue with one-photon and two-photon fluorescence microscopy and define the signal limits of optical voltage imaging with synthetic sensors under a low photon budget determined by the native expression levels of the target proteins. This work demonstrates the feasibility of a chemical targeting approach and expands the possibilities of cell-specific imaging and pharmacology.


Assuntos
Encéfalo , Cocaína/análogos & derivados , Dopamina/análise , Corantes Fluorescentes/química , Norepinefrina/análise , Animais , Encéfalo/citologia , Cocaína/síntese química , Cocaína/química , Corantes Fluorescentes/síntese química , Camundongos , Microscopia de Fluorescência , Modelos Moleculares , Estrutura Molecular , Imagem Óptica
5.
Thromb J ; 18: 6, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32292291

RESUMO

BACKGROUND: African Americans are under-represented in trials evaluating oral anticoagulants for the treatment of acute venous thromboembolism (VTE). The aim of this study was to evaluate the effectiveness and safety of rivaroxaban versus warfarin for the treatment of VTE in African Americans. METHODS: We utilized Optum® De-Identified Electronic Health Record data from 11/1/2012-9/30/2018. We included African Americans experiencing an acute VTE during a hospital or emergency department visit, who received rivaroxaban or warfarin as their first oral anticoagulant within 7-days of the acute VTE event and had ≥1 provider visit in the prior 12-months. Differences in baseline characteristics between cohorts were adjusted using inverse probability-of-treatment weighting based on propensity scores (standard differences < 0.10 were achieved for all covariates). Our primary endpoint was the composite of recurrent VTE or major bleeding at 6-months. Three- and 12-month timepoints were also assessed. Secondary endpoints included recurrent VTE and major bleeding as individual endpoints. Cohort risk was compared using Cox regression and reported as hazard ratios (HRs) with 95% confidence intervals (CIs). RESULTS: We identified 2097 rivaroxaban and 2842 warfarin users with incident VTE. At 6-months, no significant differences in the composite endpoint (HR = 0.96, 95%CI = 0.75-1.24), recurrent VTE (HR = 1.02, 95%CI = 0.76-1.36) or major bleeding alone (HR = 0.93, 95%CI = 0.59-1.47) were observed between cohorts. Analysis at 3- and 12-months provided consistent findings for these endpoints. CONCLUSIONS: In African Americans experiencing an acute VTE, no significant difference in the incidence of recurrent VTE or major bleeding was observed between patients receiving rivaroxaban or warfarin.

6.
Mol Genet Metab ; 126(4): 439-447, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30683556

RESUMO

Seizures are a feature not only of the many forms of epilepsy, but also of global metabolic diseases such as mitochondrial encephalomyopathy (ME) and glycolytic enzymopathy (GE). Modern anti-epileptic drugs (AEDs) are successful in many cases, but some patients are refractory to existing AEDs, which has led to a surge in interest in clinically managed dietary therapy such as the ketogenic diet (KD). This high-fat, low-carbohydrate diet causes a cellular switch from glycolysis to fatty acid oxidation and ketone body generation, with a wide array of downstream effects at the genetic, protein, and metabolite level that may mediate seizure protection. We have recently shown that a Drosophila model of human ME (ATP61) responds robustly to the KD; here, we have investigated the mechanistic importance of the major metabolic consequences of the KD in the context of this bioenergetics disease: ketogenesis, reduction of glycolysis, and anaplerosis. We have found that reduction of glycolysis does not confer seizure protection, but that dietary supplementation with ketone bodies or the anaplerotic lipid triheptanoin, which directly replenishes the citric acid cycle, can mimic the success of the ketogenic diet even in the presence of standard carbohydrate levels. We have also shown that the proper functioning of the citric acid cycle is crucial to the success of the KD in the context of ME. Furthermore, our data reveal that multiple seizure models, in addition to ATP61, are treatable with the ketogenic diet. Importantly, one of these mutants is TPIsugarkill, which models human glycolytic enzymopathy, an incurable metabolic disorder with severe neurological consequences. Overall, these studies reveal widespread success of the KD in Drosophila, further cementing its status as an excellent model for studies of KD treatment and mechanism, and reveal key insights into the therapeutic potential of dietary therapy against neuronal hyperexcitability in epilepsy and metabolic disease.


Assuntos
Dieta Cetogênica , Glicólise , Encefalomiopatias Mitocondriais/dietoterapia , Convulsões/prevenção & controle , Animais , Suplementos Nutricionais , Modelos Animais de Doenças , Drosophila , Proteínas de Drosophila/genética , Corpos Cetônicos/administração & dosagem , Encefalomiopatias Mitocondriais/complicações , ATPases Mitocondriais Próton-Translocadoras/genética , Convulsões/dietoterapia , Convulsões/etiologia , Triglicerídeos/administração & dosagem
7.
PLoS Genet ; 12(3): e1005941, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27031109

RESUMO

Triosephosphate isomerase (TPI) deficiency is a poorly understood disease characterized by hemolytic anemia, cardiomyopathy, neurologic dysfunction, and early death. TPI deficiency is one of a group of diseases known as glycolytic enzymopathies, but is unique for its severe patient neuropathology and early mortality. The disease is caused by missense mutations and dysfunction in the glycolytic enzyme, TPI. Previous studies have detailed structural and catalytic changes elicited by disease-associated TPI substitutions, and samples of patient erythrocytes have yielded insight into patient hemolytic anemia; however, the neuropathophysiology of this disease remains a mystery. This study combines structural, biochemical, and genetic approaches to demonstrate that perturbations of the TPI dimer interface are sufficient to elicit TPI deficiency neuropathogenesis. The present study demonstrates that neurologic dysfunction resulting from TPI deficiency is characterized by synaptic vesicle dysfunction, and can be attenuated with catalytically inactive TPI. Collectively, our findings are the first to identify, to our knowledge, a functional synaptic defect in TPI deficiency derived from molecular changes in the TPI dimer interface.


Assuntos
Anemia Hemolítica Congênita não Esferocítica/genética , Erros Inatos do Metabolismo dos Carboidratos/genética , Drosophila melanogaster/genética , Doenças do Sistema Nervoso/genética , Vesículas Sinápticas/genética , Triose-Fosfato Isomerase/deficiência , Triose-Fosfato Isomerase/genética , Anemia Hemolítica Congênita não Esferocítica/patologia , Animais , Comportamento Animal , Erros Inatos do Metabolismo dos Carboidratos/patologia , Cristalografia por Raios X , Dimerização , Humanos , Mutação de Sentido Incorreto , Doenças do Sistema Nervoso/patologia , Conformação Proteica , Vesículas Sinápticas/patologia , Triose-Fosfato Isomerase/química , Triose-Fosfato Isomerase/metabolismo
8.
Neurobiol Dis ; 120: 126-138, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30171891

RESUMO

In Huntington disease (HD), an expanded polyglutamine (polyQ > 37) sequence within huntingtin (htt) exon1 leads to enhanced disease risk. It has proved difficult, however, to determine whether the toxic form generated by polyQ expansion is a misfolded or avid-binding monomer, an α-helix-rich oligomer, or a ß-sheet-rich amyloid fibril. Here we describe an engineered htt exon1 analog featuring a short polyQ sequence that nonetheless quickly forms amyloid fibrils and causes HD-like toxicity in rat neurons and Drosophila. Additional modifications within the polyQ segment produce htt exon1 analogs that populate only spherical oligomers and are non-toxic in cells and flies. Furthermore, in mixture with expanded-polyQ htt exon1, the latter analogs in vitro suppress amyloid formation and promote oligomer formation, and in vivo rescue neurons and flies expressing mhtt exon1 from dysfunction and death. Thus, in our experiments, while htt exon1 toxicity tracks with aggregation propensity, it does so in spite of the toxic construct's possessing polyQ tracts well below those normally considered to be disease-associated. That is, aggregation propensity proves to be a more accurate surrogate for toxicity than is polyQ repeat length itself, strongly supporting a major toxic role for htt exon1 aggregation in HD. In addition, the results suggest that the aggregates that are most toxic in these model systems are amyloid-related. These engineered analogs are novel tools for mapping properties of polyQ self-assembly intermediates and products that should similarly be useful in the analysis of other expanded polyQ diseases. Small molecules with similar amyloid inhibitory properties might be developed into effective therapeutic agents.


Assuntos
Amiloide/genética , Doença de Huntington/genética , Doença de Huntington/patologia , Mutação/genética , Peptídeos/genética , Sequência de Aminoácidos , Animais , Animais Geneticamente Modificados , Animais Recém-Nascidos , Drosophila , Humanos , Ratos
9.
Neurobiol Dis ; 117: 203-210, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29908326

RESUMO

Mitochondrial encephalomyopathies (MEs) result from mutations in mitochondrial genes critical to oxidative phosphorylation. Severe and untreatable ME results from mutations affecting each endogenous mitochondrial encoded gene, including all 13 established protein coding genes. Effective techniques to manipulate mitochondrial genome are limited and targeted mitochondrial protein expression is currently unavailable. Here we report the development of a mitochondrial-targeted RNA expression (mtTRES) vector capable of protein expression within mitochondria (mtTRESPro). We demonstrate that mtTRESPro expressed RNAs are targeted to mitochondria and are capable of being translated using EGFP encoded constructs in vivo. We additionally test mtTRESPro constructs encoding wild type ATP6 for their ability to rescue an established ATP61Drosophila model of ME. Genetic rescue is examined including tests with co-expression of mitochondrial targeted translational inhibitors TLI-NCL::ATP6 RNAs that function to reduce expression of the endogenous mutant protein. The data demonstrate allotopic RNA expression of mitochondrial targeted wild type ATP6 coding RNAs are sufficient to partially rescue a severe and established animal model of ME but only when combined with a method to inhibit mutant protein expression, which likely competes for incorporation into complex V.


Assuntos
Doenças Mitocondriais/genética , Proteínas Mitocondriais/genética , Fases de Leitura Aberta/fisiologia , RNA Mitocondrial/genética , Animais , Animais Geneticamente Modificados , Células Cultivadas , Drosophila , Células HeLa , Humanos , Doenças Mitocondriais/metabolismo , Proteínas Mitocondriais/metabolismo , RNA Mitocondrial/metabolismo
10.
J Pharmacol Exp Ther ; 367(2): 348-355, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30190339

RESUMO

We present the design of an innovative molecular neuroprotective strategy and provide proof-of-concept for its implementation, relying on the injury-mediated activation of an ectopic gene construct. As oxidative injury leads to the intracellular liberation of zinc, we hypothesize that tapping onto the zinc-activated metal regulatory element (MRE) transcription factor 1 system to drive expression of the Kv2.1-targeted hepatitis C protein NS5A (hepatitis C nonstructural protein 5A) will provide neuroprotection by preventing cell death-enabling cellular potassium loss in rat cortical neurons in vitro. Indeed, using biochemical and morphologic assays, we demonstrate rapid expression of MRE-driven products in neurons. Further, we report that MRE-driven NS5A expression, induced by a slowly evolving excitotoxic stimulus, functionally blocks injurious, enhanced Kv2.1 potassium whole-cell currents and improves neuronal viability. We suggest this form of "on-demand" neuroprotection could provide the basis for a tenable therapeutic strategy to prevent neuronal cell death in neurodegeneration.


Assuntos
Hepacivirus/metabolismo , Hepatite C/metabolismo , Neuroproteção/efeitos dos fármacos , Canais de Potássio Shab/metabolismo , Proteínas não Estruturais Virais/metabolismo , Zinco/farmacologia , Animais , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Feminino , Hepatite C/virologia , Masculino , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Potássio/metabolismo , Transporte Proteico/efeitos dos fármacos , Ratos
11.
Biochim Biophys Acta ; 1852(1): 61-9, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25463631

RESUMO

Triosephosphate isomerase (TPI) is a glycolytic enzyme which homodimerizes for full catalytic activity. Mutations of the TPI gene elicit a disease known as TPI Deficiency, a glycolytic enzymopathy noted for its unique severity of neurological symptoms. Evidence suggests that TPI Deficiency pathogenesis may be due to conformational changes of the protein, likely affecting dimerization and protein stability. In this report, we genetically and physically characterize a human disease-associated TPI mutation caused by an I170V substitution. Human TPI(I170V) elicits behavioral abnormalities in Drosophila. An examination of hTPI(I170V) enzyme kinetics revealed this substitution reduced catalytic turnover, while assessments of thermal stability demonstrated an increase in enzyme stability. The crystal structure of the homodimeric I170V mutant reveals changes in the geometry of critical residues within the catalytic pocket. Collectively these data reveal new observations of the structural and kinetic determinants of TPI Deficiency pathology, providing new insights into disease pathogenesis.


Assuntos
Anemia Hemolítica Congênita não Esferocítica/patologia , Erros Inatos do Metabolismo dos Carboidratos/patologia , Domínio Catalítico , Triose-Fosfato Isomerase/deficiência , Triose-Fosfato Isomerase/metabolismo , Anemia Hemolítica Congênita não Esferocítica/enzimologia , Animais , Comportamento Animal , Erros Inatos do Metabolismo dos Carboidratos/enzimologia , Modelos Animais de Doenças , Drosophila , Estabilidade Enzimática , Humanos , Mutação , Triose-Fosfato Isomerase/química , Triose-Fosfato Isomerase/genética
12.
J Neurogenet ; 30(3-4): 247-258, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27868454

RESUMO

Effective therapies are lacking for mitochondrial encephalomyopathies (MEs). MEs are devastating diseases that predominantly affect the energy-demanding tissues of the nervous system and muscle, causing symptoms such as seizures, cardiomyopathy, and neuro- and muscular degeneration. Even common anti-epileptic drugs which are frequently successful in ameliorating seizures in other diseases tend to have a lower success rate in ME, highlighting the need for novel drug targets, especially those that may couple metabolic sensitivity to neuronal excitability. Furthermore, alternative epilepsy therapies such as dietary modification are gaining in clinical popularity but have not been thoroughly studied in ME. Using the Drosophila ATP61 model of ME, we have studied dietary therapy throughout disease progression and found that it is highly effective against the seizures of ME, especially a high fat/ketogenic diet, and that the benefits are dependent upon a functional KATP channel complex. Further experiments with KATP show that it is seizure-protective in this model, and that pharmacological promotion of its open state also ameliorates seizures. These studies represent important steps forward in the development of novel therapies for a class of diseases that is notoriously difficult to treat, and lay the foundation for mechanistic studies of currently existing therapies in the context of metabolic disease.


Assuntos
Proteínas de Drosophila/metabolismo , Encefalomiopatias Mitocondriais/dietoterapia , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Animais , Restrição Calórica , Dieta Cetogênica , Modelos Animais de Doenças , Proteínas de Drosophila/genética , Encefalomiopatias Mitocondriais/complicações , Encefalomiopatias Mitocondriais/metabolismo , ATPases Mitocondriais Próton-Translocadoras/genética , Mutação , Canais de Potássio/genética , Canais de Potássio/metabolismo , Convulsões/etiologia , Convulsões/metabolismo
13.
J Cell Sci ; 126(Pt 14): 3151-8, 2013 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-23641070

RESUMO

Triosephosphate isomerase (TPI) is a glycolytic enzyme that converts dihydroxyacetone phosphate (DHAP) into glyceraldehyde 3-phosphate (GAP). Glycolytic enzyme dysfunction leads to metabolic diseases collectively known as glycolytic enzymopathies. Of these enzymopathies, TPI deficiency is unique in the severity of neurological symptoms. The Drosophila sugarkill mutant closely models TPI deficiency and encodes a protein prematurely degraded by the proteasome. This led us to question whether enzyme catalytic activity was crucial to the pathogenesis of TPI sugarkill neurological phenotypes. To study TPI deficiency in vivo we developed a genomic engineering system for the TPI locus that enables the efficient generation of novel TPI genetic variants. Using this system we demonstrate that TPI sugarkill can be genetically complemented by TPI encoding a catalytically inactive enzyme. Furthermore, our results demonstrate a non-metabolic function for TPI, the loss of which contributes significantly to the neurological dysfunction in this animal model.


Assuntos
Anemia Hemolítica Congênita não Esferocítica/enzimologia , Erros Inatos do Metabolismo dos Carboidratos/enzimologia , Drosophila melanogaster/fisiologia , Longevidade , Paralisia/enzimologia , Triose-Fosfato Isomerase/deficiência , Triose-Fosfato Isomerase/metabolismo , Anemia Hemolítica Congênita não Esferocítica/genética , Animais , Erros Inatos do Metabolismo dos Carboidratos/genética , Catálise , Fosfato de Di-Hidroxiacetona/metabolismo , Modelos Animais de Doenças , Drosophila melanogaster/enzimologia , Feminino , Técnicas de Inativação de Genes , Teste de Complementação Genética , Engenharia Genética , Gliceraldeído 3-Fosfato/metabolismo , Glicólise/genética , Temperatura Alta/efeitos adversos , Masculino , Mutação/genética , Paralisia/genética , Estresse Fisiológico/genética , Transgenes/genética , Triose-Fosfato Isomerase/genética
14.
Neurobiol Dis ; 69: 15-22, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24807207

RESUMO

Endogenous mitochondrial genes encode critical oxidative phosphorylation components and their mutation results in a set of disorders known collectively as mitochondrial encephalomyopathies. There is intensive interest in modulating mitochondrial function as organelle dysfunction has been associated with numerous disease states. Proteins encoded by the mitochondrial genome cannot be genetically manipulated by current techniques. Here we report the development of a mitochondrial-targeted RNA expression system (mtTRES) utilizing distinct non-coding leader sequences (NCLs) and enabling in vivo expression of small mitochondrial-targeted RNAs. mtTRES expressing small chimeric antisense RNAs was used as translational inhibitors (TLIs) to target endogenous mitochondrial protein expression in vivo. By utilizing chimeric antisense RNA we successfully modulate expression of two mitochondrially-encoded proteins, ATP6 and COXII, and demonstrate the utility of this system in vivo and in human cells. This technique has important and obvious research and clinical implications.


Assuntos
Proteínas Mitocondriais/metabolismo , Biossíntese de Proteínas , RNA Antissenso/genética , Pequeno RNA não Traduzido/genética , Envelhecimento/metabolismo , Animais , Animais Geneticamente Modificados , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/metabolismo , Drosophila , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Técnicas de Silenciamento de Genes , Vetores Genéticos , Células HeLa , Humanos , Mitocôndrias/metabolismo , Encefalomiopatias Mitocondriais/metabolismo , Proteínas Mitocondriais/genética , ATPases Mitocondriais Próton-Translocadoras/genética , ATPases Mitocondriais Próton-Translocadoras/metabolismo , Estabilidade de RNA , RNA Antissenso/metabolismo , Pequeno RNA não Traduzido/metabolismo
15.
Neurobiol Dis ; 54: 289-96, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23318931

RESUMO

Triose phosphate isomerase (TPI) is responsible for the interconversion of dihydroxyacetone phosphate to glyceraldehyde-3-phosphate in glycolysis. Point mutations in this gene are associated with a glycolytic enzymopathy called TPI deficiency. This study utilizes a Drosophila melanogaster model of TPI deficiency; TPI(sugarkill) is a mutant allele with a missense mutation (M80T) that causes phenotypes similar to human TPI deficiency. In this study, the redox status of TPI(sugarkill) flies was examined and manipulated to provide insight into the pathogenesis of this disease. Our data show that TPI(sugarkill) animals exhibit higher levels of the oxidized forms of NAD(+), NADP(+) and glutathione in an age-dependent manner. Additionally, we demonstrate that mitochondrial redox state is significantly more oxidized in TPI(sugarkill) animals. We hypothesized that TPI(sugarkill) animals may be more sensitive to oxidative stress and that this may underlie the progressive nature of disease pathogenesis. The effect of oxidizing and reducing stressors on behavioral phenotypes of the TPI(sugarkill) animals was tested. As predicted, oxidative stress worsened these phenotypes. Importantly, we discovered that reducing stress improved the behavioral and longevity phenotypes of the mutant organism without having an effect on TPI(sugarkill) protein levels. Overall, these data suggest that reduced activity of TPI leads to an oxidized redox state in these mutants and that the alleviation of this stress using reducing compounds can improve the mutant phenotypes.


Assuntos
Mitocôndrias/metabolismo , Estresse Oxidativo/fisiologia , Triose-Fosfato Isomerase/deficiência , Anemia Hemolítica Congênita não Esferocítica/genética , Anemia Hemolítica Congênita não Esferocítica/metabolismo , Animais , Western Blotting , Drosophila melanogaster , Oxirredução , Mutação Puntual , Triose-Fosfato Isomerase/genética
16.
Blood ; 117(21): 5692-700, 2011 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-21454451

RESUMO

Previous studies have established a role of vascular-disrupting agents as anti- cancer agents. Plinabulin is a novel vascular-disrupting agent that exhibits potent interruption of tumor blood flow because of the disruption of tumor vascular endothelial cells, resulting in tumor necrosis. In addition, plinabulin exerts a direct action on tumor cells, resulting in apoptosis. In the present study, we examined the anti-multiple myeloma (MM) activity of plinabulin. We show that low concentrations of plinabulin exhibit a potent antiangiogenic action on vascular endothelial cells. Importantly, plinabulin also induces apoptotic cell death in MM cell lines and tumor cells from patients with MM, associated with mitotic growth arrest. Plinabulin-induced apoptosis is mediated through activation of caspase-3, caspase-8, caspase-9, and poly(ADP-ribose) polymerase cleavage. Moreover, plinabulin triggered phosphorylation of stress response protein JNK, as a primary target, whereas blockade of JNK with a biochemical inhibitor or small interfering RNA strategy abrogated plinabulin-induced mitotic block or MM cell death. Finally, in vivo studies show that plinabulin was well tolerated and significantly inhibited tumor growth and prolonged survival in a human MM.1S plasmacytoma murine xenograft model. Our study therefore provides the rationale for clinical evaluation of plinabulin to improve patient outcome in MM.


Assuntos
Inibidores da Angiogênese/farmacologia , Apoptose/efeitos dos fármacos , Imidazóis/farmacologia , Proteína Quinase 8 Ativada por Mitógeno/metabolismo , Mieloma Múltiplo/irrigação sanguínea , Mieloma Múltiplo/tratamento farmacológico , Neovascularização Patológica/prevenção & controle , Piperazinas/farmacologia , Animais , Western Blotting , Proliferação de Células/efeitos dos fármacos , Dicetopiperazinas , Imunofluorescência , Humanos , Masculino , Camundongos , Camundongos SCID , Proteína Quinase 8 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 8 Ativada por Mitógeno/genética , RNA Interferente Pequeno/genética , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
17.
Cancer Cell ; 8(5): 407-19, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16286248

RESUMO

Bortezomib therapy has proven successful for the treatment of relapsed and/or refractory multiple myeloma (MM); however, prolonged treatment is associated with toxicity and development of drug resistance. Here, we show that the novel proteasome inhibitor NPI-0052 induces apoptosis in MM cells resistant to conventional and Bortezomib therapies. NPI-0052 is distinct from Bortezomib in its chemical structure, effects on proteasome activities, mechanisms of action, and toxicity profile against normal cells. Moreover, NPI-0052 is orally bioactive. In animal tumor model studies, NPI-0052 is well tolerated and prolongs survival, with significantly reduced tumor recurrence. Combining NPI-0052 and Bortezomib induces synergistic anti-MM activity. Our study therefore provides the rationale for clinical protocols evaluating NPI-0052, alone and together with Bortezomib, to improve patient outcome in MM.


Assuntos
Ácidos Borônicos/farmacologia , Lactonas/farmacologia , Mieloma Múltiplo/tratamento farmacológico , Inibidores de Proteases/farmacologia , Pirazinas/farmacologia , Pirróis/farmacologia , Administração Oral , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Ácidos Borônicos/uso terapêutico , Bortezomib , Caspases/metabolismo , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sinergismo Farmacológico , Genes bcl-2 , Humanos , Lactonas/administração & dosagem , Lactonas/química , Linfócitos/efeitos dos fármacos , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , NF-kappa B/metabolismo , Plasmocitoma/tratamento farmacológico , Complexo de Endopeptidases do Proteassoma/farmacologia , Pirazinas/uso terapêutico , Pirróis/administração & dosagem , Pirróis/química , Células Tumorais Cultivadas
18.
Curr Biol ; 33(23): 5160-5168.e7, 2023 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-37989309

RESUMO

Toxic cardiotonic steroids (CTSs) act as a defense mechanism in many firefly species (Lampyridae) by inhibiting a crucial enzyme called Na+,K+-ATPase (NKA). Although most fireflies produce these toxins internally, species of the genus Photuris acquire them from a surprising source: predation on other fireflies. The contrasting physiology of toxin exposure and sequestration between Photuris and other firefly genera suggests that distinct strategies may be required to prevent self-intoxication. Our study demonstrates that both Photuris and their firefly prey have evolved highly resistant NKAs. Using an evolutionary analysis of the specific target of CTS (ATPα) in fireflies and gene editing in Drosophila, we find that the initial steps toward resistance were shared among Photuris and other firefly lineages. However, the Photuris lineage subsequently underwent multiple rounds of gene duplication and neofunctionalization, resulting in the development of ATPα paralogs that are differentially expressed and exhibit increasing resistance to CTS. By contrast, other firefly species have maintained a single copy. Our results implicate gene duplication as a facilitator in the transition of Photuris to its distinct ecological role as a predator of toxic firefly prey.


Assuntos
Vaga-Lumes , Comportamento Predatório , Animais , Evolução Biológica
19.
Science ; 379(6636): 996-1003, 2023 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-36893255

RESUMO

Metabolic networks are interconnected and influence diverse cellular processes. The protein-metabolite interactions that mediate these networks are frequently low affinity and challenging to systematically discover. We developed mass spectrometry integrated with equilibrium dialysis for the discovery of allostery systematically (MIDAS) to identify such interactions. Analysis of 33 enzymes from human carbohydrate metabolism identified 830 protein-metabolite interactions, including known regulators, substrates, and products as well as previously unreported interactions. We functionally validated a subset of interactions, including the isoform-specific inhibition of lactate dehydrogenase by long-chain acyl-coenzyme A. Cell treatment with fatty acids caused a loss of pyruvate-lactate interconversion dependent on lactate dehydrogenase isoform expression. These protein-metabolite interactions may contribute to the dynamic, tissue-specific metabolic flexibility that enables growth and survival in an ever-changing nutrient environment.


Assuntos
Metabolismo dos Carboidratos , L-Lactato Desidrogenase , Metaboloma , Humanos , Ácidos Graxos/metabolismo , L-Lactato Desidrogenase/metabolismo , Especificidade de Órgãos , Espectrometria de Massas/métodos , Regulação Alostérica
20.
bioRxiv ; 2023 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-37873436

RESUMO

Parkinson's disease (PD) targets some dopamine (DA) neurons more than others. Sex differences offer insights, with females more protected from DA neurodegeneration. The mammalian vesicular glutamate transporter VGLUT2 and Drosophila ortholog dVGLUT have been implicated as modulators of DA neuron resilience. However, the mechanisms by which VGLUT2/dVGLUT protects DA neurons remain unknown. We discovered DA neuron dVGLUT knockdown increased mitochondrial reactive oxygen species in a sexually dimorphic manner in response to depolarization or paraquat-induced stress, males being especially affected. DA neuron dVGLUT also reduced ATP biosynthetic burden during depolarization. RNA sequencing of VGLUT+ DA neurons in mice and flies identified candidate genes that we functionally screened to further dissect VGLUT-mediated DA neuron resilience across PD models. We discovered transcription factors modulating dVGLUT-dependent DA neuroprotection and identified dj-1ß as a regulator of sex-specific DA neuron dVGLUT expression. Overall, VGLUT protects DA neurons from PD-associated degeneration by maintaining mitochondrial health.

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