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1.
Placenta ; 132: 32-37, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36623417

RESUMO

INTRODUCTION: Total alkaline phosphatase (tALP) levels rise physiologically in maternal serum during pregnancy, and excessively so in certain conditions. However, current reference values are dated, nonlinear, and based on small samples. Factors related to variation in tALP remain unexplained. Thus, our goals in this study were to establish a physiological development curve for tALP within low-risk pregnancies and to evaluate the factors influencing tALP values. METHODS: This was a single-center, retrospective, observational study. All patients who delivered a live singleton infant at our center from January 1, 2011 to May 31, 2019, and had a tALP assay during pregnancy, were included regardless of the gestational age at which the assay was conducted. RESULTS: A total of 2415 pregnancies were included. Median tALP decreased during the first trimester, it increased slightly during the second trimester, and then increased sharply during the third trimester. Factors associated with a significant increase in tALP were chronic histiocytic intervillositis, cholestasis, multiple pregnancies, liver disease, preeclampsia, smoking, and low weight for gestational age. Conversely, gestational diabetes was associated with a discrete decrease in tALP. DISCUSSION: Our large sample allowed establishment of tALP reference curves based on gestational age. To interpret these results more thoroughly, factors that influence tALP rates should be further scrutinized.


Assuntos
Fosfatase Alcalina , Idade Gestacional , Feminino , Humanos , Gravidez , Fosfatase Alcalina/sangue , Segundo Trimestre da Gravidez , Estudos Retrospectivos
2.
J Clin Invest ; 132(22)2022 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-36377661

RESUMO

Cisplatin is a potent chemotherapeutic drug that is widely used in the treatment of various solid cancers. However, its clinical effectiveness is strongly limited by frequent severe adverse effects, in particular nephrotoxicity and chemotherapy-induced peripheral neuropathy. Thus, there is an urgent medical need to identify novel strategies that limit cisplatin-induced toxicity. In the present study, we show that the FDA-approved adenosine A2A receptor antagonist istradefylline (KW6002) protected from cisplatin-induced nephrotoxicity and neuropathic pain in mice with or without tumors. Moreover, we also demonstrate that the antitumoral properties of cisplatin were not altered by istradefylline in tumor-bearing mice and could even be potentiated. Altogether, our results support the use of istradefylline as a valuable preventive approach for the clinical management of patients undergoing cisplatin treatment.


Assuntos
Antineoplásicos , Neuralgia , Animais , Camundongos , Cisplatino/efeitos adversos , Purinas/farmacologia , Neuralgia/induzido quimicamente , Receptor A2A de Adenosina , Antineoplásicos/efeitos adversos
3.
Front Endocrinol (Lausanne) ; 13: 957245, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36120456

RESUMO

Background: A number of epidemiological studies have suggested an association between metabolic dysfunction-associated fatty liver disease (MAFLD) and the incidence of atrial fibrillation (AF). However, the pathogenesis leading to AF in the context of MAFLD remains unclear. We therefore aimed at assessing the impact of MAFLD and liver fibrosis status on left atrium (LA) structure and function. Methods: Patients with a Fatty Liver Index (FLI) >60 and the presence of metabolic comorbidities were classified as MAFLD+. In MAFLD+ patients, liver fibrosis severity was defined using the non-alcoholic fatty liver disease (NAFLD) Fibrosis Score (NFS), as follows: MAFLD w/o fibrosis (NFS ≦ -1.455), MAFLD w/indeterminate fibrosis (-1.455 < NFS < 0.675), and MAFLD w/fibrosis (NFS ≧ 0.675). In the first cohort of patients undergoing AF ablation, the structural and functional impact on LA of MAFLD was assessed by LA strain analysis and endocardial voltage mapping. Histopathological assessment of atrial fibrosis was performed in the second cohort of patients undergoing cardiac surgery. Finally, the impact of MAFLD on AF recurrence following catheter ablation was assessed. Results: In the AF ablation cohort (NoMAFLD n = 123; MAFLD w/o fibrosis n = 37; MAFLD indeterm. fibrosis n = 75; MAFLD w/severe fibrosis n = 10), MAFLD patients with high risk of F3-F4 liver fibrosis presented more LA low-voltage areas as compared to patients without MAFLD (16.5 [10.25; 28] vs 5.0 [1; 11] low-voltage areas p = 0.0115), impaired LA reservoir function assessed by peak left atrial longitudinal strain (19.7% ± 8% vs 8.9% ± 0.89% p = 0.0268), and increased LA volume (52.9 ± 11.7 vs 43.5 ± 18.0 ml/m2 p = 0.0168). Accordingly, among the MAFLD patients, those with a high risk of F3-F4 liver fibrosis presented a higher rate of AF recurrence during follow-up (p = 0.0179). In the cardiac surgery cohort (NoMAFLD n = 12; MAFLD w/o fibrosis n = 5; MAFLD w/fibrosis n = 3), an increase in histopathological atrial fibrosis was observed in MAFLD patients with a high risk of F3-F4 liver fibrosis (p = 0.0206 vs NoMAFLD; p = 0.0595 vs MAFLD w/o fibrosis). Conclusion: In conclusion, we found that liver fibrosis scoring in MAFLD patients is associated with adverse atrial remodeling and AF recurrences following catheter ablation. The impact of the management of MAFLD on LA remodeling and AF ablation outcomes should be assessed in dedicated studies.


Assuntos
Fibrilação Atrial , Remodelamento Atrial , Ablação por Cateter , Fibrilação Atrial/etiologia , Fibrilação Atrial/patologia , Fibrilação Atrial/cirurgia , Ablação por Cateter/efeitos adversos , Fibrose , Humanos , Cirrose Hepática/complicações , Cirrose Hepática/cirurgia
4.
Mol Metab ; 55: 101410, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34863941

RESUMO

OBJECTIVE: Long-term treatment with tyrosine kinase inhibitors (TKI) represents an effective cure for chronic myeloid leukemia (CML) patients and discontinuation of TKI therapy is now proposed to patient with deep molecular responses. However, evidence demonstrating that TKI are unable to fully eradicate dormant leukemic stem cells (LSC) indicate that new therapeutic strategies are needed to control LSC and to prevent relapse. In this study we investigated the metabolic pathways responsible for CML surviving to imatinib exposure and its potential therapeutic utility to improve the efficacy of TKI against stem-like CML cells. METHODS: Using complementary cell-based techniques, metabolism was characterized in a large panel of BCR-ABL+ cell lines as well as primary CD34+ stem-like cells from CML patients exposed to TKI and L-Asparaginases. Colony forming cell (CFC) assay and flow cytometry were used to identify CML progenitor and stem like-cells. Preclinical models of leukemia dormancy were used to test the effect of treatments. RESULTS: Although TKI suppressed glycolysis, compensatory glutamine-dependent mitochondrial oxidation supported ATP synthesis and CML cell survival. Glutamine metabolism was inhibited by L-asparaginases such as Kidrolase or Erwinase without inducing predominant CML cell death. However, clinically relevant concentrations of TKI render CML cells susceptible to Kidrolase. The combination of TKI with Lasparaginase reactivates the intinsic apoptotic pathway leading to efficient CML cell death. CONCLUSION: Targeting glutamine metabolism with the FDA-approved drug, Kidrolase in combination with TKI that suppress glycolysis represents an effective and widely applicable therapeutic strategy for eradicating stem-like CML cells.


Assuntos
Mesilato de Imatinib/farmacologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Células-Tronco Neoplásicas/metabolismo , Animais , Apoptose/efeitos dos fármacos , Asparaginase/metabolismo , Asparaginase/farmacologia , Asparagina/antagonistas & inibidores , Asparagina/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Humanos , Mesilato de Imatinib/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Camundongos , Células-Tronco Neoplásicas/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/metabolismo
6.
Clin Biochem ; 92: 71-76, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33766514

RESUMO

Owing to their ease of use, glucose meters are frequently used in research and medicine. However, little is known of whether other non-glucose molecules, besides vitamin C, interfere with glucometry. Therefore, we sought to determine whether other antioxidants might behave like vitamin C in causing falsely elevated blood glucose levels, potentially exposing patients to glycemic mismanagement by being administered harmful doses of glucose-lowering drugs. To determine whether various antioxidants can be detected by seven commercial glucose meters, human blood samples were spiked with various antioxidants ex vivo and their effect on the glucose results were assessed by Parkes error grid analysis. Several of the glucose meters demonstrated a positive bias in the glucose measurement of blood samples spiked with vitamin C, N-acetylcysteine, and glutathione. With the most interference-sensitive glucose meter, non-blood solutions of 1 mmol/L N-acetylcysteine, glutathione, cysteine, vitamin C, dihydrolipoate, and dithiothreitol mimicked the results seen on that glucose meter for 0.7, 1.0, 1.2, 2.6, 3.7 and 5.5 mmol/L glucose solutions, respectively. Glucose meter users should be alerted that some of these devices might produce spurious glucose results not only in patients on vitamin C therapy but also in those being administered other antioxidants. As discussed herein, the clinical relevance of the data is immediate in view of the current use of antioxidant therapies for disorders such as the metabolic syndrome, diabetes, cardiovascular diseases, and coronavirus disease 2019.


Assuntos
Antioxidantes/química , Automonitorização da Glicemia/instrumentação , Glicemia/análise , Acetilcisteína/sangue , Acetilcisteína/química , Antioxidantes/análise , Antioxidantes/metabolismo , Ácido Ascórbico/análise , Ácido Ascórbico/sangue , Glicemia/química , Automonitorização da Glicemia/métodos , Glutationa/sangue , Glutationa/química , Humanos , Sistemas Automatizados de Assistência Junto ao Leito
7.
Shock ; 56(4): 629-638, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33534395

RESUMO

ABSTRACT: Sepsis is the leading cause of acute kidney injury (AKI) in critical care patients. A cornerstone of sepsis-associated AKI is dysregulated inflammation driven by excessive activation of Toll-like receptor 4 (TLR4) pathway. MUC1, a membrane-bound mucin expressed in both epithelial tubular cells and renal macrophages, has been shown to be involved in the regulation of TLRs. Therefore, we hypothesized that MUC1 could mitigate the renal inflammatory response to TLR4 activation. To test this hypothesis, we used a murine model of endotoxin-induced AKI by intraperitoneal injection of LPS. We showed that Muc1-/- mice have a more severe renal dysfunction, an increased activation of the tissular NF-kB pathway and secreted more pro inflammatory cytokines compare to Muc1+/+ mice. By flow cytometry, we observed that the proportion of M1 (pro-inflammatory) macrophages in the kidneys of Muc1-/- mice was significantly increased. In human and murine primary macrophages, we showed that MUC1 is only induced in M1 type macrophages and that macrophages derived from Muc1-/- mice secreted more pro-inflammatory cytokines. Eventually, in HEK293 cells, we showed that MUC1 cytosolic domain (CT) seems necessary for the negative regulation of TLR4 by proximity ligation assay, MUC1-CT is in close relationship with TLR4 and acts as a competitive inhibitor of the recruitment of MYD88. Overall our results support that in the context of endotoxin-induced AKI, MUC1 plays a significant role in controlling disease severity by regulating negatively the TLR4-MD2 axis.


Assuntos
Injúria Renal Aguda/etiologia , Antígeno 96 de Linfócito/fisiologia , Macrófagos/fisiologia , Mucina-1/fisiologia , Receptor 4 Toll-Like/fisiologia , Injúria Renal Aguda/metabolismo , Injúria Renal Aguda/patologia , Animais , Endotoxinas , Feminino , Inflamação , Masculino , Camundongos , Camundongos Endogâmicos C57BL
8.
Int J Mol Sci ; 23(1)2021 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-35008535

RESUMO

Mitochondrial dysfunctions are implicated in several pathologies, such as metabolic, cardiovascular, respiratory, and neurological diseases, as well as in cancer and aging. These metabolic alterations are usually assessed in human or murine samples by mitochondrial respiratory chain enzymatic assays, by measuring the oxygen consumption of intact mitochondria isolated from tissues, or from cells obtained after physical or enzymatic disruption of the tissues. However, these methodologies do not maintain tissue multicellular organization and cell-cell interactions, known to influence mitochondrial metabolism. Here, we develop an optimal model to measure mitochondrial oxygen consumption in heart and lung tissue samples using the XF24 Extracellular Flux Analyzer (Seahorse) and discuss the advantages and limitations of this technological approach. Our results demonstrate that tissue organization, as well as mitochondrial ultrastructure and respiratory function, are preserved in heart and lung tissues freshly processed or after overnight conservation at 4 °C. Using this method, we confirmed the repeatedly reported obesity-associated mitochondrial dysfunction in the heart and extended it to the lungs. We set up and validated a new strategy to optimally assess mitochondrial function in murine tissues. As such, this method is of great potential interest for monitoring mitochondrial function in cohort samples.


Assuntos
Consumo de Oxigênio/fisiologia , Envelhecimento/fisiologia , Animais , Comunicação Celular/fisiologia , Linhagem Celular , Linhagem Celular Tumoral , Respiração Celular/fisiologia , Metabolismo Energético/fisiologia , Coração/fisiologia , Humanos , Pulmão/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/fisiologia , Membranas Mitocondriais/fisiologia , Ratos , Testes de Função Respiratória/métodos
9.
Diabetologia ; 64(2): 325-338, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33219433

RESUMO

AIMS/HYPOTHESIS: Early compromised endothelial function challenges the ability of individuals with type 1 diabetes to perform normal physical exercise. The exact mechanisms underlying this vascular limitation remain unknown, but may involve either formation or metabolism of nitric oxide (NO), a major vasodilator, whose activity is known to be compromised by oxidative stress. METHODS: Muscle microvascular reactivity (near-infrared spectroscopy) to an incremental exhaustive bout of exercise was assessed in 22 adults with uncomplicated type 1 diabetes (HbA1c 64.5 ± 15.7 mmol/mol; 8.0 ± 1.4%) and in 21 healthy individuals (18-40 years of age). NO-related substrates/metabolites were also measured in the blood along with other vasoactive compounds and oxidative stress markers; measurements were taken at rest, at peak exercise and after 15 min of recovery. Demographic characteristics, body composition, smoking status and diet were comparable in both groups. RESULTS: Maximal oxygen uptake was impaired in individuals with type 1 diabetes compared with in healthy participants (35.6 ± 7.7 vs 39.6 ± 6.8 ml min-1 kg-1, p < 0.01) despite comparable levels of habitual physical activity (moderate to vigorous physical activity by accelerometery, 234.9 ± 160.0 vs 280.1 ± 114.9 min/week). Compared with non-diabetic participants, individuals with type 1 diabetes also displayed a blunted exercise-induced vasoreactivity (muscle blood volume at peak exercise as reflected by ∆ total haemoglobin, 2.03 ± 5.82 vs 5.33 ± 5.54 µmol/l; interaction 'exercise' × 'group', p < 0.05); this was accompanied by lower K+ concentration (p < 0.05), reduced plasma L-arginine (p < 0.05)-in particular when HbA1c was high (mean estimation: -4.0, p < 0.05)-and lower plasma urate levels (p < 0.01). Nonetheless, exhaustive exercise did not worsen lipid peroxidation or other oxidative stress biomarkers, and erythrocytic enzymatic antioxidant resources were mobilised to a comparable extent in both groups. Nitrite and total nitrosation products, which are potential alternative NO sources, were similarly unaltered. Graphical abstract CONCLUSIONS/INTERPRETATION: Participants with uncomplicated type 1 diabetes displayed reduced availability of L-arginine, the essential substrate for enzymatic nitric oxide synthesis, as well as lower levels of the major plasma antioxidant, urate. Lower urate levels may reflect a defect in the activity of xanthine oxidase, an enzyme capable of producing NO from nitrite under hypoxic conditions. Thus, both canonical and non-canonical NO production may be reduced. However, neither of these changes exacerbated exercise-induced oxidative stress. TRIAL REGISTRATION: clinicaltrials.gov NCT02051504.


Assuntos
Diabetes Mellitus Tipo 1/metabolismo , Exercício Físico/fisiologia , Músculo Esquelético/irrigação sanguínea , Óxido Nítrico/metabolismo , Estresse Oxidativo , Vasodilatação/fisiologia , Adolescente , Adulto , Arginina/metabolismo , Estudos de Casos e Controles , Diabetes Mellitus Tipo 1/fisiopatologia , Endotélio Vascular/fisiopatologia , Feminino , Humanos , Peroxidação de Lipídeos , Masculino , Microvasos/fisiopatologia , Músculo Esquelético/metabolismo , Consumo de Oxigênio/fisiologia , Espectroscopia de Luz Próxima ao Infravermelho , Ácido Úrico/metabolismo , Adulto Jovem
11.
Ann Biol Clin (Paris) ; 77(3): 281-286, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31115339

RESUMO

Extreme leukocytosis may lead to false hyperkalemia when blood samples are conveyed by pneumatic tube system (PTS). The aim of this study was to define whether even moderate leukocytosis and also non malignancy cells like neutrophils may influence potassium values after PTS transportation. MATERIALS AND METHODS: Uncentrifuged blood samples are sent to the local laboratory through PTS. Data were retrospectively collected from routine testing carried out on all specimens arrived in the laboratory between September 2017 and March 2018. Clinical chemistry testing is routinely performed using lithium-heparin tubes. When false hyperkalemia induced by leukocytosis is suspected, potassium measurement is then performed in serum (clotting activator tubes) or whole blood samples. The analysis was focused on samples with both leukocytosis (i.e., >15×109/L) and plasma potassium >5.0 mmol/L, before any corrective therapeutic measure to lower potassium levels was established. RESULTS: A total number of 18 samples were included in our analysis, 9 drawn from patients with hematologic malignancies and 9 without. In the 9 patients without hematologic malignancies (median leukocyte count, 20.4×109/L), the median potassium value was 5.4 mmol/L in plasma and 4.5 mmol/L in serum or whole blood. In the 9 patients with hematologic malignancies (median leukocyte count, 151.9×109/L; p <0.001), the median potassium value was 7.7 mmol/L in plasma and 4.3 mmol/L in serum or whole blood (median difference, 2.9 mmol/L; p <0.001). CONCLUSION: The results of our study suggest that even modest leukocytosis (i.e., around 15x109/L), which can be frequently encountered in clinical practice, may be associated with a significant variation of plasma potassium. This would lead us to conclude that plasma samples transportation by PTS should be avoided in patients with even mild leukocytosis.


Assuntos
Coleta de Amostras Sanguíneas/efeitos adversos , Ar Comprimido/efeitos adversos , Hiperpotassemia/diagnóstico , Leucocitose/diagnóstico , Fase Pré-Analítica/métodos , Meios de Transporte/métodos , Artefatos , Coleta de Amostras Sanguíneas/métodos , Estudos de Casos e Controles , Diagnóstico Diferencial , Reações Falso-Positivas , Neoplasias Hematológicas/sangue , Humanos , Hiperpotassemia/sangue , Hiperpotassemia/etiologia , Inflamação/sangue , Leucocitose/sangue , Leucocitose/etiologia , Potássio/análise , Potássio/sangue , Fase Pré-Analítica/normas , Estudos Retrospectivos , Meios de Transporte/normas
12.
Cell Death Dis ; 9(3): 325, 2018 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-29487283

RESUMO

Targeted therapies as BRAF and MEK inhibitor combination have been approved as first-line treatment for BRAF-mutant melanoma. However, disease progression occurs in most of the patients within few months of therapy. Metabolic adaptations have been described in the context of acquired resistance to BRAF inhibitors (BRAFi). BRAFi-resistant melanomas are characterized by an increase of mitochondrial oxidative phosphorylation and are more prone to cell death induced by mitochondrial-targeting drugs. BRAFi-resistant melanomas also exhibit an enhancement of oxidative stress due to mitochondrial oxygen consumption increase. To understand the mechanisms responsible for survival of BRAFi-resistant melanoma cells in the context of oxidative stress, we have established a preclinical murine model that accurately recapitulates in vivo the acquisition of resistance to MAPK inhibitors including several BRAF or MEK inhibitors alone and in combination. Using mice model and melanoma cell lines generated from mice tumors, we have confirmed that the acquisition of resistance is associated with an increase in mitochondrial oxidative phosphorylation as well as the importance of glutamine metabolism. Moreover, we have demonstrated that BRAFi-resistant melanoma can adapt mitochondrial metabolism to support glucose-derived glutamate synthesis leading to increase in glutathione content. Besides, BRAFi-resistant melanoma exhibits a strong activation of NRF-2 pathway leading to increase in the pentose phosphate pathway, which is involved in the regeneration of reduced glutathione, and to increase in xCT expression, a component of the xc-amino acid transporter essential for the uptake of cystine required for intracellular glutathione synthesis. All these metabolic modifications sustain glutathione level and contribute to the intracellular redox balance to allow survival of BRAFi-resistant melanoma cells.


Assuntos
Antioxidantes/metabolismo , Resistencia a Medicamentos Antineoplásicos , Glucose/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Melanoma/metabolismo , Melanoma/patologia , Fator 2 Relacionado a NF-E2/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Feminino , Glutamatos/biossíntese , Glutationa/biossíntese , Humanos , Camundongos SCID , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Fosforilação Oxidativa/efeitos dos fármacos , Ácido Pirúvico/metabolismo
13.
Int J Biochem Cell Biol ; 85: 166-174, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28259749

RESUMO

Cancer cell metabolism is largely controlled by oncogenic signals and nutrient availability. Here, we highlighted that the glucocorticoid-induced leucine zipper (GILZ), an intracellular protein influencing many signaling pathways, reprograms cancer cell metabolism to promote proliferation. We provided evidence that GILZ overexpression induced a significant increase of mitochondrial oxidative phosphorylation as evidenced by the augmentation in basal respiration, ATP-linked respiration as well as respiratory capacity. Pharmacological inhibition of glucose, glutamine and fatty acid oxidation reduced the activation of GILZ-induced mitochondrial oxidative phosphorylation. At glycolysis level, GILZ-overexpressing cells enhanced the expression of glucose transporters in their plasmatic membrane and showed higher glycolytic reserve. 1H NMR metabolites quantification showed an up-regulation of amino acid biosynthesis. The GILZ-induced metabolic reprograming is present in various cancer cell lines regardless of their driver mutations status and is associated with higher proliferation rates persisting under metabolic stress conditions. Interestingly, high levels of OXPHOS made GILZ-overexpressing cells vulnerable to cell death induced by mitochondrial pro-oxidants. Altogether, these data indicate that GILZ reprograms cancer metabolism towards mitochondrial OXPHOS and sensitizes cancer cells to mitochondria-targeted drugs with pro-oxidant activities.


Assuntos
Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Mitocôndrias/metabolismo , Animais , Antineoplásicos/farmacologia , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sistemas de Liberação de Medicamentos , Citometria de Fluxo , Expressão Gênica/efeitos dos fármacos , Glucocorticoides/farmacologia , Hidrazinas/farmacologia , Metaboloma/efeitos dos fármacos , Camundongos , Mitocôndrias/efeitos dos fármacos , Oxirredução , Reação em Cadeia da Polimerase em Tempo Real , Sulfetos/farmacologia , Tiadiazóis/farmacologia
14.
PLoS One ; 8(6): e66750, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23799132

RESUMO

Renal proximal tubular epithelial cells play a central role in renal physiology and are among the cell types most sensitive to ischemia and xenobiotic nephrotoxicity. In order to investigate the molecular and cellular mechanisms underlying the pathophysiology of kidney injuries, a stable and well-characterized primary culture model of proximal tubular cells is required. An existing model of proximal tubular cells is hampered by the cellular heterogeneity of kidney; a method based on cell sorting for specific markers must therefore be developed. In this study, we present a primary culture model based on the mechanical and enzymatic dissociation of healthy tissue obtained from nephrectomy specimens. Renal epithelial cells were sorted using co-labeling for CD10 and CD13, two renal proximal tubular epithelial markers, by flow cytometry. Their purity, phenotypic stability and functional properties were evaluated over several passages. Our results demonstrate that CD10/CD13 double-positive cells constitute a pure, functional and stable proximal tubular epithelial cell population that displays proximal tubule markers and epithelial characteristics over the long term, whereas cells positive for either CD10 or CD13 alone appear to be heterogeneous. In conclusion, this study describes a method for establishing a robust renal proximal tubular epithelial cell model suitable for further experimentation.


Assuntos
Antígenos CD13/metabolismo , Células Epiteliais/fisiologia , Túbulos Renais Proximais/citologia , Neprilisina/metabolismo , Antígenos CD13/química , Separação Celular , Forma Celular , Células Cultivadas , Impedância Elétrica , Células Epiteliais/ultraestrutura , Citometria de Fluxo , Humanos , Nefrectomia , Neprilisina/química , Fenótipo , Cultura Primária de Células , Coloração e Rotulagem
15.
Hemoglobin ; 36(6): 581-5, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23092150

RESUMO

Acquired α-thalassemia (α-thal) myelodysplastic syndrome (ATMDS) is a rare acquired syndrome characterized by a somatic point mutation in the ATRX gene in patients with chronic myeloid disorders. We describe the case of a 78-year-old man with myelodysplastic syndrome (MDS) and striking microcytic, hypochromic anemia. Brilliant cresyl blue supravital stain of the peripheral blood and hemoglobin (Hb) electrophoresis showed the presence of Hb H. Sequence analysis of unfractionated peripheral blood DNA identified a G>T transition at codon 524 in exon 7 of the ATRX gene. To the best of our knowledge, it is the first description of this point mutation of the ATRX gene in an ATMDS.


Assuntos
DNA Helicases/genética , Mutação , Síndromes Mielodisplásicas/genética , Proteínas Nucleares/genética , Talassemia alfa/genética , Idoso , Sequência de Bases , Éxons , Humanos , Masculino , Síndromes Mielodisplásicas/diagnóstico , Síndromes Mielodisplásicas/terapia , Proteína Nuclear Ligada ao X , Talassemia alfa/diagnóstico , Talassemia alfa/terapia
16.
Cancer Res ; 72(19): 5035-47, 2012 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-22865452

RESUMO

Cancer cells can undergo a metabolic reprogramming from oxidative phosphorylation to glycolysis that allows them to adapt to nutrient-poor microenvironments, thereby imposing a selection for aggressive variants. However, the mechanisms underlying this reprogramming are not fully understood. Using complementary approaches in validated cell lines and freshly obtained human specimens, we report here that mitochondrial respiration and oxidative phosphorylation are slowed in metastatic melanomas, even under normoxic conditions due to the persistence of a high nuclear expression of hypoxia-inducible factor-1α (HIF-1α). Pharmacologic or genetic blockades of the HIF-1α pathway decreased glycolysis and promoted mitochondrial respiration via specific reduction in the expression of pyruvate dehydrogenase kinase-3 (PDK3). Inhibiting PDK3 activity by dichloroacetate (DCA) or siRNA-mediated attenuation was sufficient to increase pyruvate dehydrogenase activity, oxidative phosphorylation, and mitochondrial reactive oxygen species generation. Notably, DCA potentiated the antitumor effects of elesclomol, a pro-oxidative drug currently in clinical development, both by limiting cell proliferation and promoting cell death. Interestingly, this combination was also effective against BRAF V600E-mutant melanoma cells that were resistant to the BRAF inhibitor vemurafenib. Cotreatment of melanomas with DCA and elesclomol in vivo achieved a more durable response than single agent alone. Our findings offer a preclinical validation of the HIF-1/PDK3 bioenergetic pathway as a new target for therapeutic intervention in metastatic melanoma, opening the door to innovative combinations that might eradicate this disease.


Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Melanoma/metabolismo , Mitocôndrias/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Idoso , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Ácido Dicloroacético/administração & dosagem , Ácido Dicloroacético/farmacologia , Feminino , Células HL-60 , Humanos , Hidrazinas/administração & dosagem , Hidrazinas/farmacologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/antagonistas & inibidores , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Immunoblotting , Masculino , Melanoma/tratamento farmacológico , Melanoma/patologia , Camundongos , Camundongos SCID , Pessoa de Meia-Idade , Mitocôndrias/efeitos dos fármacos , Fosforilação Oxidativa/efeitos dos fármacos , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/genética , Piruvato Desidrogenase Quinase de Transferência de Acetil , Interferência de RNA , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
17.
PLoS One ; 6(7): e21924, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21789194

RESUMO

Challenges today concern chronic myeloid leukemia (CML) patients resistant to imatinib. There is growing evidence that imatinib-resistant leukemic cells present abnormal glucose metabolism but the impact on mitochondria has been neglected. Our work aimed to better understand and exploit the metabolic alterations of imatinib-resistant leukemic cells. Imatinib-resistant cells presented high glycolysis as compared to sensitive cells. Consistently, expression of key glycolytic enzymes, at least partly mediated by HIF-1α, was modified in imatinib-resistant cells suggesting that imatinib-resistant cells uncouple glycolytic flux from pyruvate oxidation. Interestingly, mitochondria of imatinib-resistant cells exhibited accumulation of TCA cycle intermediates, increased NADH and low oxygen consumption. These mitochondrial alterations due to the partial failure of ETC were further confirmed in leukemic cells isolated from some imatinib-resistant CML patients. As a consequence, mitochondria generated more ROS than those of imatinib-sensitive cells. This, in turn, resulted in increased death of imatinib-resistant leukemic cells following in vitro or in vivo treatment with the pro-oxidants, PEITC and Trisenox, in a syngeneic mouse tumor model. Conversely, inhibition of glycolysis caused derepression of respiration leading to lower cellular ROS. In conclusion, these findings indicate that imatinib-resistant leukemic cells have an unexpected mitochondrial dysfunction that could be exploited for selective therapeutic intervention.


Assuntos
Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Leucemia/patologia , Leucemia/fisiopatologia , Mitocôndrias/patologia , Piperazinas/farmacologia , Pirimidinas/farmacologia , Animais , Trióxido de Arsênio , Arsenicais/farmacologia , Benzamidas , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Respiração Celular/efeitos dos fármacos , Transporte de Elétrons/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Glucose/metabolismo , Mesilato de Imatinib , Isotiocianatos/farmacologia , Leucemia/metabolismo , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/ultraestrutura , Modelos Biológicos , Estresse Oxidativo/efeitos dos fármacos , Óxidos/farmacologia , Espécies Reativas de Oxigênio/metabolismo
18.
Ann Clin Biochem ; 47(Pt 1): 94-6, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19940199

RESUMO

False elevations of plasma lactate dehydrogenase (LDH), potassium and aspartate aminotransferase (AST) have been described, in relation to haemolysis, occurring most often by mechanical release during phlebotomy or specimen processing. We present the cases of two leukaemic patients with severe hyperleukocytosis for whom LDH, potassium and AST were dramatically but falsely elevated. This false elevation was not caused by haemolysis but could be related to white cells lysis during transport through a pneumatic transportation system, enhanced by a specific fragility of leukaemic cells. Interestingly, this interference almost completely disappeared when serum rather than plasma was used, or when leukocytosis came back to normal. This work is meant to alert clinicians to the risks of errors in LDH, potassium and AST in leukaemic patients and suggest what precautions to take.


Assuntos
Análise Química do Sangue/métodos , Coleta de Amostras Sanguíneas/métodos , Leucemia/sangue , Leucocitose/sangue , Meios de Transporte/métodos , Adolescente , Adulto , Aspartato Aminotransferases/análise , Aspartato Aminotransferases/sangue , Análise Química do Sangue/normas , Estudos de Avaliação como Assunto , Reações Falso-Positivas , Feminino , Humanos , L-Lactato Desidrogenase/análise , L-Lactato Desidrogenase/sangue , Leucemia/complicações , Leucocitose/complicações , Leucocitose/diagnóstico , Potássio/análise , Potássio/sangue
19.
Haematologica ; 92(6): 850-3, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17550861

RESUMO

We quantified and studied the impact of post transfusional iron overload alone in post allogeneic HSCT. Median number of RBCs was 18. Ferritin was 532 mg/L. Liver iron content (LIC) was 117 mmoles/gdw. Correlation RBCs and ferritin was (r=0.81); RBCs and LIC was (r=0.84). The high ferritin group differed from normal ferritin group in terms of RBCs transfused (p<10(-3)), ALT (p<0.009). But occurrence of liver dysfunction was not significant. Magnitude of iron overload correlates closely to the number of RBCs and is quantified by MRI. Impact on liver dysfunction is moderate in absence of co-morbidity.


Assuntos
Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Sobrecarga de Ferro/diagnóstico , Imageamento por Ressonância Magnética/métodos , Adolescente , Adulto , Feminino , Seguimentos , Humanos , Sobrecarga de Ferro/etiologia , Hepatopatias/diagnóstico , Hepatopatias/etiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sobreviventes , Transplante Homólogo
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