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Gulias JF, Niesi F, Arán M, Correa-García S, Bermúdez-Moretti M. Gcn4 impacts metabolic fluxes to promote yeast chronological lifespan. PLoS One 2023; 18:e0292949. [PMID: 37831681 PMCID: PMC10575530 DOI: 10.1371/journal.pone.0292949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 10/02/2023] [Indexed: 10/15/2023] Open
Abstract
Aging is characterized by a gradual decline in physiological integrity, which impairs functionality and increases susceptibility to mortality. Dietary restriction, mimicking nutrient scarcity without causing malnutrition, is an intervention known to decelerate the aging process. While various hypotheses have been proposed to elucidate how dietary restriction influences aging, the underlying mechanisms remain incompletely understood. This project aimed to investigate the role of the primary regulator of the general amino acid control (GAAC) pathway, the transcription factor Gcn4, in the aging process of S. cerevisiae cells. Under conditions of amino acid deprivation, which activate Gcn4, the deletion of GCN4 led to a diverse array of physiological changes in the cells. Notably, the absence of Gcn4 resulted in heightened mitochondrial activity, likely contributing to the observed increase in reactive oxygen species (ROS) accumulation. Furthermore, these mutant gcn4Δ cells exhibited reduced ethanol production despite maintaining similar glucose consumption rates, suggesting a pivotal role for Gcn4 in regulating the Crabtree effect. Additionally, there was a marked reduction in trehalose, the storage carbohydrate, within the mutant cells compared to the wild-type strain. The intracellular content of free amino acids also exhibited disparities between the wild-type and GCN4-deficient strains. Taken together, our findings indicate that the absence of GCN4 disrupts cellular homeostasis, triggering significant alterations in interconnected intracellular metabolic pathways. These disruptions have far-reaching metabolic consequences that ultimately culminate in a shortened lifespan.
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Affiliation(s)
- Juan Facundo Gulias
- Facultad de Ciencias Exactas y Naturales, Departamento Química Biológica, Universidad de Buenos Aires, Buenos Aires, Argentina–CONICET, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Buenos Aires, Argentina
| | - Florencia Niesi
- Facultad de Ciencias Exactas y Naturales, Departamento Química Biológica, Universidad de Buenos Aires, Buenos Aires, Argentina–CONICET, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Buenos Aires, Argentina
| | - Martín Arán
- Fundación Instituto Leloir e Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA)—CONICET, Patricias Argentinas, Buenos Aires, Argentina
| | - Susana Correa-García
- Facultad de Ciencias Exactas y Naturales, Departamento Química Biológica, Universidad de Buenos Aires, Buenos Aires, Argentina–CONICET, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Buenos Aires, Argentina
| | - Mariana Bermúdez-Moretti
- Facultad de Ciencias Exactas y Naturales, Departamento Química Biológica, Universidad de Buenos Aires, Buenos Aires, Argentina–CONICET, Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Buenos Aires, Argentina
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Muñoz SA, Gulias JF, Valencia-Guillén J, Correa-García S, Bermúdez-Moretti M. Novel function of transcription factor Uga3 as an activator of branched-chain amino acid permease BAP2 gene expression. Microbiology (Reading) 2020; 166:85-92. [DOI: 10.1099/mic.0.000863] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Gene regulation in yeast occurs at the transcription level, i.e. the basal level of expression is very low and increased transcription requires gene-specific transcription factors allowing the recruitment of basal transcriptional machinery. Saccharomyces cerevisiae BAP2 gene encodes the permease responsible for most uptake of leucine, valine and isoleucine, amino acids that this yeast can use as nitrogen sources. Moreover, BAP2 expression is known to be induced by the presence of amino acids such as leucine. In this context, the results presented in this paper show that BAP2 is an inducible gene in the presence of nitrogen-non-preferred source proline but exhibits high constitutive non-inducible expression in nitrogen-preferred source ammonium. BAP2 expression is regulated by the SPS sensor system and transcription factors Leu3, Gcn4 and Dal81. This can be achieved or not through a direct binding to the promoter depending on the quality of the nitrogen source. We further demonstrate here that an interaction occurs in vivo between Uga3 ‒ the transcriptional activator responsible for γ-aminobutyric acid (GABA)-dependent induction of the GABA genes ‒ and the regulatory region of the BAP2 gene, which leads to an increase in BAP2 transcription.
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Affiliation(s)
- Sebastián A. Muñoz
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Buenos Aires, Argentina
| | - Juan F. Gulias
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Buenos Aires, Argentina
| | - Jenniffer Valencia-Guillén
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Buenos Aires, Argentina
| | - Susana Correa-García
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Buenos Aires, Argentina
| | - Mariana Bermúdez-Moretti
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales (IQUIBICEN), Buenos Aires, Argentina
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Tsivgoulis G, Ribo M, Rubiera M, Vasdekis SN, Barlinn K, Athanasiadis D, Bavarsad Shahripour R, Giannopoulos S, Stamboulis E, Harrigan MR, Molina CA, Alexandrov AV. Real-time Validation of Transcranial Doppler Criteria in Assessing Recanalization During Intra-arterial Procedures for Acute Ischemic Stroke An International, Multicenter Study. Stroke 2013; 44:394-400. [DOI: 10.1161/strokeaha.112.675074] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and Purpose—
We sought to evaluate the diagnostic accuracy of ultrasound criteria for recanalization during real-time transcranial Doppler monitoring of intra-arterial reperfusion procedures in acute ischemic stroke patients in an international, multicenter study.
Methods—
Consecutive acute ischemic stroke patients with proximal intracranial occlusions underwent intra-arterial reperfusion procedures with simultaneous real-time transcranial Doppler monitoring at 3 tertiary-care stroke centers. Residual flow signals at the site of angiographically confirmed occlusions were monitored at a constant transtemporal insonation angle using a standard head-frame. Recanalization was assessed simultaneously by digital subtraction angiography and ultrasound using thrombolysis in myocardial infarction and thrombolysis in brain ischemia (TIBI) criteria, respectively. Independent readers blinded to digital subtraction angiography performed validation of TIBI flow grades. The interrater reliability for assessment of TIBI grades was investigated.
Results—
We evaluated time-linked real-time digital subtraction angiography transcranial Doppler images from 96 diagnostic digital subtraction angiography runs during intra-arterial reperfusion procedures in 62 acute ischemic stroke patients (mean age, 59±17 years; 58% men; median baseline National Institutes of Health Stroke Scale score, 18 [interquartile range 12–21]; median time from symptom onset to intra-arterial procedure initiation, 240 minutes [interquartile range 163–308]). The interrater reliability for evaluation of TIBI grades and assessment of recanalization was good (Cohen
κ
: 0.838 and 0.874, respectively;
P
<0.001). Compared with angiography, transcranial Doppler had the following accuracy parameters for detection of complete recanalization (TIBI 4 and 5 versus thrombolysis in myocardial infarction 3, flow grades): sensitivity, 88% (95% confidence interval, 72%–96%); specificity, 89% (79%–95%); positive predictive value, 81% (65%–91%); negative predictive value, 93% (84%–98%); and overall accuracy 89% (80%–94%).
Conclusions—
At laboratories with high-interrater reliability, TIBI criteria can accurately predict brain recanalization in real time as compared with thrombolysis in myocardial infarction angiographic scores.
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Affiliation(s)
- Georgios Tsivgoulis
- From the Comprehensive Stroke Center, University of Alabama Hospital, Birmingham, AL (G.T., M.R., K.B., R.B.S., A.V.A.); Second Department of Neurology, University of Athens, School of Medicine, Athens, Greece (G.T., E.S.); International Clinical Research Center, St. Anne’s University Hospital, Brno, Czech Republic (G.T.); Department of Neurology, Hospital Universitari Vall d’Hbron, Universitat Autonoma de Barcelona, Barcelona, Spain (M.Ri., M.Ru., C.A.M.); Third Department of Surgery, Vascular Unit
| | - Marc Ribo
- From the Comprehensive Stroke Center, University of Alabama Hospital, Birmingham, AL (G.T., M.R., K.B., R.B.S., A.V.A.); Second Department of Neurology, University of Athens, School of Medicine, Athens, Greece (G.T., E.S.); International Clinical Research Center, St. Anne’s University Hospital, Brno, Czech Republic (G.T.); Department of Neurology, Hospital Universitari Vall d’Hbron, Universitat Autonoma de Barcelona, Barcelona, Spain (M.Ri., M.Ru., C.A.M.); Third Department of Surgery, Vascular Unit
| | - Marta Rubiera
- From the Comprehensive Stroke Center, University of Alabama Hospital, Birmingham, AL (G.T., M.R., K.B., R.B.S., A.V.A.); Second Department of Neurology, University of Athens, School of Medicine, Athens, Greece (G.T., E.S.); International Clinical Research Center, St. Anne’s University Hospital, Brno, Czech Republic (G.T.); Department of Neurology, Hospital Universitari Vall d’Hbron, Universitat Autonoma de Barcelona, Barcelona, Spain (M.Ri., M.Ru., C.A.M.); Third Department of Surgery, Vascular Unit
| | - Spyros N. Vasdekis
- From the Comprehensive Stroke Center, University of Alabama Hospital, Birmingham, AL (G.T., M.R., K.B., R.B.S., A.V.A.); Second Department of Neurology, University of Athens, School of Medicine, Athens, Greece (G.T., E.S.); International Clinical Research Center, St. Anne’s University Hospital, Brno, Czech Republic (G.T.); Department of Neurology, Hospital Universitari Vall d’Hbron, Universitat Autonoma de Barcelona, Barcelona, Spain (M.Ri., M.Ru., C.A.M.); Third Department of Surgery, Vascular Unit
| | - Kristian Barlinn
- From the Comprehensive Stroke Center, University of Alabama Hospital, Birmingham, AL (G.T., M.R., K.B., R.B.S., A.V.A.); Second Department of Neurology, University of Athens, School of Medicine, Athens, Greece (G.T., E.S.); International Clinical Research Center, St. Anne’s University Hospital, Brno, Czech Republic (G.T.); Department of Neurology, Hospital Universitari Vall d’Hbron, Universitat Autonoma de Barcelona, Barcelona, Spain (M.Ri., M.Ru., C.A.M.); Third Department of Surgery, Vascular Unit
| | - Dimitrios Athanasiadis
- From the Comprehensive Stroke Center, University of Alabama Hospital, Birmingham, AL (G.T., M.R., K.B., R.B.S., A.V.A.); Second Department of Neurology, University of Athens, School of Medicine, Athens, Greece (G.T., E.S.); International Clinical Research Center, St. Anne’s University Hospital, Brno, Czech Republic (G.T.); Department of Neurology, Hospital Universitari Vall d’Hbron, Universitat Autonoma de Barcelona, Barcelona, Spain (M.Ri., M.Ru., C.A.M.); Third Department of Surgery, Vascular Unit
| | - Reza Bavarsad Shahripour
- From the Comprehensive Stroke Center, University of Alabama Hospital, Birmingham, AL (G.T., M.R., K.B., R.B.S., A.V.A.); Second Department of Neurology, University of Athens, School of Medicine, Athens, Greece (G.T., E.S.); International Clinical Research Center, St. Anne’s University Hospital, Brno, Czech Republic (G.T.); Department of Neurology, Hospital Universitari Vall d’Hbron, Universitat Autonoma de Barcelona, Barcelona, Spain (M.Ri., M.Ru., C.A.M.); Third Department of Surgery, Vascular Unit
| | - Sotirios Giannopoulos
- From the Comprehensive Stroke Center, University of Alabama Hospital, Birmingham, AL (G.T., M.R., K.B., R.B.S., A.V.A.); Second Department of Neurology, University of Athens, School of Medicine, Athens, Greece (G.T., E.S.); International Clinical Research Center, St. Anne’s University Hospital, Brno, Czech Republic (G.T.); Department of Neurology, Hospital Universitari Vall d’Hbron, Universitat Autonoma de Barcelona, Barcelona, Spain (M.Ri., M.Ru., C.A.M.); Third Department of Surgery, Vascular Unit
| | - Elefterios Stamboulis
- From the Comprehensive Stroke Center, University of Alabama Hospital, Birmingham, AL (G.T., M.R., K.B., R.B.S., A.V.A.); Second Department of Neurology, University of Athens, School of Medicine, Athens, Greece (G.T., E.S.); International Clinical Research Center, St. Anne’s University Hospital, Brno, Czech Republic (G.T.); Department of Neurology, Hospital Universitari Vall d’Hbron, Universitat Autonoma de Barcelona, Barcelona, Spain (M.Ri., M.Ru., C.A.M.); Third Department of Surgery, Vascular Unit
| | - Mark R. Harrigan
- From the Comprehensive Stroke Center, University of Alabama Hospital, Birmingham, AL (G.T., M.R., K.B., R.B.S., A.V.A.); Second Department of Neurology, University of Athens, School of Medicine, Athens, Greece (G.T., E.S.); International Clinical Research Center, St. Anne’s University Hospital, Brno, Czech Republic (G.T.); Department of Neurology, Hospital Universitari Vall d’Hbron, Universitat Autonoma de Barcelona, Barcelona, Spain (M.Ri., M.Ru., C.A.M.); Third Department of Surgery, Vascular Unit
| | - Carlos A. Molina
- From the Comprehensive Stroke Center, University of Alabama Hospital, Birmingham, AL (G.T., M.R., K.B., R.B.S., A.V.A.); Second Department of Neurology, University of Athens, School of Medicine, Athens, Greece (G.T., E.S.); International Clinical Research Center, St. Anne’s University Hospital, Brno, Czech Republic (G.T.); Department of Neurology, Hospital Universitari Vall d’Hbron, Universitat Autonoma de Barcelona, Barcelona, Spain (M.Ri., M.Ru., C.A.M.); Third Department of Surgery, Vascular Unit
| | - Andrei V. Alexandrov
- From the Comprehensive Stroke Center, University of Alabama Hospital, Birmingham, AL (G.T., M.R., K.B., R.B.S., A.V.A.); Second Department of Neurology, University of Athens, School of Medicine, Athens, Greece (G.T., E.S.); International Clinical Research Center, St. Anne’s University Hospital, Brno, Czech Republic (G.T.); Department of Neurology, Hospital Universitari Vall d’Hbron, Universitat Autonoma de Barcelona, Barcelona, Spain (M.Ri., M.Ru., C.A.M.); Third Department of Surgery, Vascular Unit
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