RESUMO
We present a rare case of a patient with toluene exposure manifesting as anti-glomerular basement membrane (GBM) disease on a background of phospholipase A2 receptor (PLA2R)-associated membranous nephropathy. A 23-year-old man presented to the emergency department with hypertension, headache, hemoptysis, anemia, acute kidney injury, glomerular hematuria, and proteinuria. He endorsed repeated exposure to toluene-containing products while repairing dirt bikes. Serologies were positive for anti-GBM antibodies. Kidney biopsy showed crescentic glomerulonephritis with linear immunoglobulin G and granular PLA2R staining by immunofluorescence. He was initially treated with high-dose steroids, plasmapheresis, and hemodialysis for pulmonary-renal syndrome followed by oral cyclophosphamide and prednisone, which were discontinued after 3 months when follow-up biopsies confirmed little chance for renal recovery. He remained on dialysis 1 year later. This case exhibits a unique presentation of anti-GBM syndrome and underlying membranous nephropathy following repeated hydrocarbon exposure. Inhaled toxins promote recurrent localized inflammation, unmasking previously hidden epitopes. Early diagnosis and appropriate use of immunosuppressive and extracorporeal therapies are necessary to prevent morbidity and to improve survival in this rare condition.
Assuntos
Doença Antimembrana Basal Glomerular , Glomerulonefrite Membranosa , Humanos , Masculino , Adulto Jovem , Doença Antimembrana Basal Glomerular/induzido quimicamente , Doença Antimembrana Basal Glomerular/complicações , Doença Antimembrana Basal Glomerular/diagnóstico , Autoanticorpos , Ciclofosfamida/uso terapêutico , Glomerulonefrite Membranosa/induzido quimicamente , Glomerulonefrite Membranosa/diagnóstico , Glomerulonefrite Membranosa/tratamento farmacológico , Fosfolipases/uso terapêutico , Poliésteres/uso terapêutico , Receptores da Fosfolipase A2 , Tolueno/uso terapêuticoRESUMO
Traumatic brain injury (TBI) is one of the most common causes of death and disability worldwide. We investigated whether inhibition of p53 using pifithrin (PFT)-α or PFT-µ provides neuroprotective effects via p53 transcriptional dependent or -independent mechanisms, respectively. Sprague Dawley rats were subjected to controlled cortical impact TBI followed by the administration of PFTα or PFT-µ (2 mg/kg, i.v.) at 5 h after TBI. Brain contusion volume, as well as sensory and motor functions were evaluated at 24 h after TBI. TBI-induced impairments were mitigated by both PFT-α and PFT-µ. Fluoro-Jade C staining was used to label degenerating neurons within the TBI-induced cortical contusion region that, together with Annexin V positive neurons, were reduced by PFT-µ. Double immunofluorescence staining similarly demonstrated that PFT-µ significantly increased HO-1 positive neurons and mRNA expression in the cortical contusion region as well as decreased numbers of 4-hydroxynonenal (4HNE)-positive cells. Levels of mRNA encoding for p53, autophagy, mitophagy, anti-oxidant, anti-inflammatory related genes and proteins were measured by RT-qPCR and immunohistochemical staining, respectively. PFT-α, but not PFT-µ, significantly lowered p53 mRNA expression. Both PFT-α and PFT-µ lowered TBI-induced pro-inflammatory cytokines (IL-1ß and IL-6) mRNA levels as well as TBI-induced autophagic marker localization (LC3 and p62). Finally, treatment with PFT-µ mitigated TBI-induced declines in mRNA levels of PINK-1 and SOD2. Our data suggest that both PFT-µ and PFT-α provide neuroprotective actions through regulation of oxidative stress, neuroinflammation, autophagy, and mitophagy mechanisms, and that PFT-µ, in particular, holds promise as a TBI treatment strategy.
Assuntos
Autofagia/efeitos dos fármacos , Benzotiazóis/uso terapêutico , Lesões Encefálicas Traumáticas/tratamento farmacológico , Lesões Encefálicas Traumáticas/patologia , Encefalite/tratamento farmacológico , Mitofagia/efeitos dos fármacos , Neurônios/patologia , Fármacos Neuroprotetores/uso terapêutico , Estresse Oxidativo/efeitos dos fármacos , Sulfonamidas/uso terapêutico , Tolueno/análogos & derivados , Proteína Supressora de Tumor p53/antagonistas & inibidores , Animais , Antioxidantes/metabolismo , Comportamento Animal , Contusão Encefálica/tratamento farmacológico , Contusão Encefálica/patologia , Contusão Encefálica/psicologia , Lesões Encefálicas Traumáticas/psicologia , Citocinas/metabolismo , Encefalite/patologia , Heme Oxigenase (Desciclizante)/biossíntese , Masculino , Ratos , Ratos Sprague-Dawley , Tolueno/uso terapêuticoRESUMO
To evaluate the effect of mitogen-activated protein kinase (MAPK) signal transduction pathway inhibitors against alveolar echinococcosis in vitro and in vivo, Echinococcus multilocularis metacestode cysts and protoscolices were obtained from infected mice. Protein chip technology was utilized to screen for key highly expressed target proteins in the MAPK pathway in this parasite and their corresponding inhibitors. Four-week-old Balb/c female mice used for the in vivo experiment underwent inoculation of E. multilocularis by intraperitoneal injection, as well as intragastric administration of MAPK inhibitors for 6 wk. We included 6 groups of mice: a phosphate-buffered saline (PBS) group (negative control); an albendazole-treated group (positive group); and 4 experimental groups treated with TRx0237 mesylate, GDC-0994, pifithrin-ß hydrobromide, or Selonsertib. Echinococcus multilocularis protoscolices were collected and cultured in 1066 medium with penicillin/streptomycin and 10% fetal bovine serum. The in vitro experiment included a PBS group (negative control), a dimethyl sulfoxide-treated group (solvent group), and 4 inhibitor-treated groups as in the in vivo experiment (experimental groups). Each inhibitor group received 4 drug concentrations (5, 30, 55, and 80 µM), and the experiment was performed in triplicate per sample. Fluorescence microscopy was used to evaluate the survival rate of the protoscolices every 48 hr beginning from the first 24 hr. The same grouping was used to evaluate cytotoxicity on E. multilocularis germinal cells and L02 cells. The average weights of E. multilocularis metacestode cyst tissue from each group of the in vivo experiment were 873 mg (PBS), 335 mg (albendazole), 323 mg (TRx0237 mesylate), 420 mg (GDC-0994), 340 mg (pifithrin-ß hydrobromide), and 642 mg (Selonsertib). Results showed albendazole, TRx0237 mesylate, and pifithrin-ß hydrobromide had significant inhibitory effects on inhibition of E. multilocularis. We found a positive correlation between drug concentrations and the inhibitory effects seen in the in vitro experiment, with the differences in contrast with the control group becoming statistically significant after 72 hr of treatment ( P < 0.05). The inhibition rates of TRx0237 mesylate to germinal cells by drug concentration were 23.73, 46.59, 74.71, and 77.44%. Other drugs had no effect on germinal cells. All the inhibitors had low toxicity on L02 cells. Inhibitors of the MAPK signal transduction pathway showed significant inhibitory effects on E. multilocularis, suggesting these may be potential candidates for the treatment of alveolar echinococcosis.
Assuntos
Anti-Helmínticos/farmacologia , Equinococose/tratamento farmacológico , Echinococcus multilocularis/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Transdução de Sinais/efeitos dos fármacos , Albendazol/farmacologia , Albendazol/uso terapêutico , Animais , Anti-Helmínticos/química , Anti-Helmínticos/uso terapêutico , Benzamidas/química , Benzamidas/farmacologia , Benzamidas/uso terapêutico , Peso Corporal/efeitos dos fármacos , Linhagem Celular , Modelos Animais de Doenças , Equinococose/enzimologia , Feminino , Hepatócitos/parasitologia , Compostos Heterocíclicos de 4 ou mais Anéis/química , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Compostos Heterocíclicos de 4 ou mais Anéis/uso terapêutico , Humanos , Imidazóis/química , Imidazóis/farmacologia , Imidazóis/uso terapêutico , Concentração Inibidora 50 , Azul de Metileno/análogos & derivados , Azul de Metileno/química , Azul de Metileno/farmacologia , Azul de Metileno/uso terapêutico , Camundongos , Camundongos Endogâmicos BALB C , Análise Serial de Proteínas , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/uso terapêutico , Piridinas/química , Piridinas/farmacologia , Piridinas/uso terapêutico , Tolueno/análogos & derivados , Tolueno/química , Tolueno/farmacologia , Tolueno/uso terapêuticoRESUMO
The cyclin kinase inhibitor p21 is acutely upregulated during acute kidney injury (AKI) and exerts cytoprotective effects. A proposed mechanism is oxidant stress-induced activation of p53, the dominant p21 transcription factor. Glycerol-induced rhabdomyolysis induces profound renal oxidant stress. Hence, we studied this AKI model to determine whether p53 activation corresponds with p21 gene induction and/or whether alternative mechanism(s) might be involved. CD-1 mice were subjected to glycerol-induced AKI. After 4 or 18 h, plasma, urinary, and renal cortical p21 protein and mRNA levels were assessed. Renal p53 activation was gauged by measurement of both total and activated (Ser15-phosphorylated) p53 and p53 mRNA levels. Glycerol evoked acute, progressive increases in renal cortical p21 mRNA and protein levels. Corresponding plasma (~25-fold) and urinary (~75-fold) p21 elevations were also observed. Renal cortical ratio of total to phosphorylated (Ser15) p53 rose three- to fourfold. However, the p53 inhibitor pifithrin-α failed to block glycerol-induced p21 gene induction, suggesting that an alternative p21 activator might also be at play. To this end, it was established that glycerol-induced AKI 1) dramatically increased plasma (~5-fold) and urinary (~75-fold) cortisol levels, 2) the glucocorticoid receptor antagonist mifepristone blocked glycerol-induced p21 mRNA and protein accumulation, and 3) dexamethasone or cortisol injections markedly increased p21 protein and mRNA in both normal and glycerol-treated mice, although no discernible p53 protein or mRNA increases were observed. We conclude that AKI-induced "systemic stress" markedly increases plasma and urinary cortisol, which can then activate renal p21 gene expression, at least in part, via a glucocorticoid receptor-dependent signaling pathway. Discernible renal cortical p53 increases are not required for this dexamethasone-mediated p21 response.
Assuntos
Injúria Renal Aguda/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/biossíntese , Glucocorticoides/metabolismo , Transdução de Sinais , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/fisiopatologia , Animais , Benzotiazóis/uso terapêutico , Dexametasona/uso terapêutico , Glicerol , Antagonistas de Hormônios/uso terapêutico , Hidrocortisona/sangue , Hidrocortisona/uso terapêutico , Hidrocortisona/urina , Córtex Renal/metabolismo , Masculino , Camundongos , Mifepristona/uso terapêutico , Tolueno/análogos & derivados , Tolueno/uso terapêutico , Proteína Supressora de Tumor p53/antagonistas & inibidores , Proteína Supressora de Tumor p53/metabolismo , Regulação para CimaRESUMO
BACKGROUND/AIMS: Immunosuppression frequently occurs during the development of sepsis and is closely associated with poor outcome. Characteristics of immunosuppressive CD4+ T lymphocytes in sepsis have been reported to include dramatic cell loss and inactivation. p53 acts as a pivotal transcription factor in regulating cell proliferation and apoptosis, which control tumorigenesis. However, few studies have investigated the universal role of p53 in immune cells, especially in the development of sepsis. METHODS: A mouse model of sepsis was produced by cecal ligation and puncture (CLP), and isolated splenic CD4+ T cells or Jurkat cells were exposed to lipopolysaccharide (LPS) stimulation in vitro. We used genetic knockout (p53-/-) mice or the specific inhibitor pifithrin-α (PFT) to investigate the regulatory mechanisms of p53. Cell proliferation ability was assessed using a Cell Counting Kit-8 assay, and apoptotic cells were stained with annexin V/propidium iodide and then analyzed using a FACScan flow cytometer. Protein and mRNA expression levels were measured by western blotting and real-time PCR, and cytokine levels in culture supernatants were determined by enzyme-linked immunosorbent assay. RESULTS: Splenic CD4+ T lymphocytes from CLP mice expressed gradually elevated p53 mRNA and protein levels, which resulted in extracellular regulated protein kinase 1/2 inactivation and expression of apoptotic molecules. Specific inhibition of p53 by PFT or genetic knockout (p53-/-) maintained CD4+ T lymphocyte homeostasis, as indicated by protection from cell loss and restoration of immune function. A medium dose of PFT improved the survival rate of mice, while mortality rate showed only a slight improvement in p53-/- mice compared with wild-type mice. The in vitro responses to LPS were consistent with these results, and upregulation of p53 clearly affected the proliferation, apoptosis, and immune dysfunction of CD4+ T lymphocytes. In addition, we confirmed the regulatory effect of p53 in Jurkat cells, and inhibition of p53 by either inhibition or short hairpin RNA transduction markedly protected cells from LPS stimulation. CONCLUSION: Elevation of p53 in T lymphocytes during sepsis or endotoxin challenge might be responsible for inhibiting cell proliferation and enhancing both apoptosis and immune dysfunction of T cells.
Assuntos
Linfócitos T CD4-Positivos/metabolismo , Sepse/patologia , Proteína Supressora de Tumor p53/metabolismo , Animais , Apoptose/efeitos dos fármacos , Benzotiazóis/farmacologia , Benzotiazóis/uso terapêutico , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Modelos Animais de Doenças , Humanos , Células Jurkat , Lipopolissacarídeos/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Sepse/tratamento farmacológico , Sepse/mortalidade , Taxa de Sobrevida , Tolueno/análogos & derivados , Tolueno/farmacologia , Tolueno/uso terapêutico , Proteína Supressora de Tumor p53/antagonistas & inibidores , Proteína Supressora de Tumor p53/genética , Regulação para Cima/efeitos dos fármacosRESUMO
OBJECTIVE: To explore the potential effect of miR-125b on p53-mediated regulation of Bax/Cytochrome C/Caspase-3 apoptotic signaling pathway in rats with cerebral ischemia-reperfusion (CIR) injury. METHODS: Sprague-Dawley (SD) rats were used to conduct CIR injury and injected with miR-125b mimic/inhibitor or p53 inhibitor (Pifithrin-α, PFT-α). Dual-luciferase reporter gene assay was used to analyze the targeting relationship between miR-125b and p53. Longa scoring and Triphenyl tetrazolinm chloride (TTC) staining were used to test the neurologic function and determine infarct size, respectively. Hematoxylin-eosin (HE) and Nissl's stainings were conducted to observe the morphology of cortical neurons. Neuronal nuclei (NeuN) expression was detected by immunohistochemical staining. QRT-PCR was performed to detect the expressions of miR-125b and p53. TUNEL staining and Western blotting was used to determine neuronal apoptosis and expressions of Bax/Cytochrome C/Caspase-3 signaling pathway-related proteins, respectively. RESULTS: Our results showed that miR-125b could directly target p53. As observed, overexpression of miR-125b could obviously reduce the neurological score, infarct size, and brain water content after CIR in rats, which also improved the morphology of cortical neurons, increased the number of neurons, reduced neuronal apoptosis, and inhibited the expressions of Bax/Cytochrome C/Caspase-3 pathway. Moreover,the similar results were observed in rats with CIR after injected with PFT-α. But no significant differences in each index were found in CIR group and CIR + anti-miR-125b + PFT-α group. CONCLUSION: MiR-125b exerts protective effects on CIR injury through inhibition of Bax/Cytochrome C/Caspase-3signaling pathway via targeting p53, which is likely to be a promising treatment for CIR. ABBREVIATIONS: 3'-UTR: 3-untranslated region; CIR: cerebral ischemia-reperfusion; CIS: cerebral ischemic stroke; PFT-α: Pifithrin-α; PVDF: polyvinylidene fluoride; SD: Sprague-Dawley; TBST: tris buffered saline with tween. TTC staining: Triphenyl tetrazolinm chloride staining; TUNEL: Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling.
Assuntos
Apoptose/fisiologia , MicroRNAs/uso terapêutico , Traumatismo por Reperfusão/terapia , Transdução de Sinais/fisiologia , Proteína Supressora de Tumor p53/metabolismo , Proteína X Associada a bcl-2/metabolismo , Animais , Apoptose/efeitos dos fármacos , Benzotiazóis/farmacologia , Benzotiazóis/uso terapêutico , Infarto Encefálico/etiologia , Infarto Encefálico/prevenção & controle , Isquemia Encefálica/complicações , Isquemia Encefálica/terapia , Caspase 3/metabolismo , Caspases/metabolismo , Citocromos c/metabolismo , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Regulação da Expressão Gênica/efeitos dos fármacos , Masculino , MicroRNAs/metabolismo , Fosfopiruvato Hidratase/metabolismo , Ratos , Ratos Sprague-Dawley , Traumatismo por Reperfusão/complicações , Transdução de Sinais/efeitos dos fármacos , Tolueno/análogos & derivados , Tolueno/farmacologia , Tolueno/uso terapêutico , Proteína X Associada a bcl-2/genéticaRESUMO
OBJECTIVE: Although cerebral ischemia can activate endogenous reparative processes, such as proliferation of endogenous neural stem cells (NSCs) in the subventricular zone (SVZ) and subgranular zone (SGZ), the majority of these new cells die shortly after injury and do not appropriately differentiate into neurons, or migrate and functionally integrate into the brain. The purpose of this study was to examine a novel strategy for treatment of stroke after injury by optimizing the survival of ischemia-induced endogenous NSCs in the SVZ and SGZ. METHODS: Adult SVZ and SGZ NSCs were grown as neurospheres in culture and treated with a p53 inactivator, pifithrin-α (PFT-α), and an amyloid precursor protein (APP)-lowering drug, posiphen, and effects on neurosphere number, size and neuronal differentiation were evaluated. This combined sequential treatment approach was then evaluated in mice challenged with middle cerebral artery occlusion (MCAo). Locomotor behavior and cognition were evaluated at 4 weeks, and the number of new surviving neurons was quantified in nestin creERT2-YFP mice. RESULTS: PFT-α and posiphen enhanced the self-renewal, proliferation rate and neuronal differentiation of adult SVZ and SGZ NSCs in culture. Their sequential combination in mice challenged with MCAo-induced stroke mitigated locomotor and cognitive impairments and increased the survival of SVZ and SGZ NSCs cells. PFT-α and the combined posiphen+PFT-α treatment similarly improved locomotion behavior in stroke challenged mice. Notably, however, the combined treatment provided significantly more potent cognitive function enhancement in stroke mice, as compared with PFT-α single treatment. INTERPRETATION: Delayed combined sequential treatment with an inhibitor of p53 dependent apoptosis (PFT-α) and APP synthesis (posiphen) proved able to enhance stroke-induced endogenous neurogenesis and improve the functional recovery in stroke animals. Whereas the combined sequential treatment provided no further improvement in locomotor function, as compared with PFT-α alone treatment, suggesting a potential ceiling in the locomotion behavioral outcome in stroke animals, combined treatment more potently augmented cognitive function recovery after stroke.
Assuntos
Benzotiazóis/uso terapêutico , Neurogênese , Fisostigmina/análogos & derivados , Recuperação de Função Fisiológica , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/fisiopatologia , Tolueno/análogos & derivados , Animais , Atrofia , Benzotiazóis/farmacologia , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Autorrenovação Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Cognição/efeitos dos fármacos , Quimioterapia Combinada , Ventrículos Laterais/patologia , Ventrículos Laterais/fisiopatologia , Masculino , Camundongos Endogâmicos C57BL , Proteínas Associadas aos Microtúbulos/metabolismo , Atividade Motora/efeitos dos fármacos , Células-Tronco Neurais/efeitos dos fármacos , Células-Tronco Neurais/metabolismo , Neurogênese/efeitos dos fármacos , Fisostigmina/farmacologia , Fisostigmina/uso terapêutico , Recuperação de Função Fisiológica/efeitos dos fármacos , Esferoides Celulares/efeitos dos fármacos , Esferoides Celulares/metabolismo , Tolueno/farmacologia , Tolueno/uso terapêuticoRESUMO
BACKGROUND: The small molecule pifithrin-µ reversibility inhibits the mitochondrial pathway of apoptosis. The neuronal effects of pifithrin-µ applied after cardiac arrest are unknown. We hypothesized that pifithrin-µ reduces neuronal damage in the most vulnerable brain region, the hippocampus, after cardiac arrest. METHODS: In two randomized controlled series we administered pifithrin-µ or control in 109 rats resuscitated after 8 or 10 min of cardiac arrest. Neuronal damage was blindly assessed with histology (Fluoro Jade B: FJB, cresyl violet: CV) in the most vulnerable brain region (CA1 segment of hippocampus) and with a series of neurobehavioral tests (Open Field Task, Tape-Removal Test, Morris Water Maze test). Mixed ANOVA was used to combine both series, simple comparisons were done with t tests or Mann-Whitney U test. RESULTS: Pifithrin-µ reduced the number of degenerating, FJB-positive neurons by 25% (mixed ANOVA p groupâ=â0.014). This was more prominent after 8 min cardiac arrest (8âmin arrest pifithrin-µ 94â±â47 vs control 128â±â37; nâ=â11 each; 10 min arrest pifithrin-µ 78â±â44, nâ=â15 vs control 101â±â31, nâ=â18; p group* arrest length interactionâ=â0.622). The reduction of ischemic CV-positive neurons in pifithrin-µ animals was not significant (ANOVA p groupâ=â0.063). No significant group differences were found in neurobehavioral testing. CONCLUSION: Temporarily inhibition of apoptosis with pifithrin-µ after cardiac arrest decreases the number of injured neurons in the CA1 segment of hippocampus in a cardiac arrest rat model, without clinical correlate. Further studies should elucidate the role of this neuroprotective agent in different settings and with longer cardiac arrest.
Assuntos
Benzotiazóis/uso terapêutico , Parada Cardíaca/tratamento farmacológico , Parada Cardíaca/metabolismo , Tolueno/análogos & derivados , Proteína Supressora de Tumor p53/antagonistas & inibidores , Proteína Supressora de Tumor p53/metabolismo , Animais , Apoptose/efeitos dos fármacos , Masculino , Neuroproteção/efeitos dos fármacos , Distribuição Aleatória , Ratos , Ratos Wistar , Tolueno/uso terapêuticoRESUMO
p53 plays an essential role in the regulation of cell death in dopaminergic (DA) neurons and its activation has been implicated in the neurotoxic effects of methamphetamine (MA). However, how p53 mediates MA neurotoxicity remains largely unknown. In this study, we examined the effect of DA-specific p53 gene deletion in DAT-p53KO mice. Whereas in vivo MA binge exposure reduced locomotor activity in wild-type (WT) mice, this was significantly attenuated in DAT-p53KO mice and associated with significant differences in the levels of the p53 target genes BAX and p21 between WT and DAT-p53KO. Notably, DA-specific deletion of p53 provided protection of substantia nigra pars reticulata (SNpr) tyrosine hydroxylase (TH) positive fibers following binge MA, with DAT-p53KO mice having less decline of TH protein levels in striatum versus WT mice. Whereas DAT-p53KO mice demonstrated a consistently higher density of TH fibers in striatum compared to WT mice at 10 days after MA exposure, DA neuron counts within the substantia nigra pars compacta (SNpc) were similar. Finally, supportive of these results, administration of a p53-specific inhibitor (PFT-α) provided a similarly protective effect on MA binge-induced behavioral deficits. Neither DA specific p53 deletion nor p53 pharmacological inhibition affected hyperthermia induced by MA binge. These findings demonstrate a specific contribution of p53 activation in behavioral deficits and DA neuronal terminal loss by MA binge exposure.
Assuntos
Estimulantes do Sistema Nervoso Central/toxicidade , Proteínas da Membrana Plasmática de Transporte de Dopamina/deficiência , Metanfetamina/toxicidade , Síndromes Neurotóxicas/etiologia , Síndromes Neurotóxicas/metabolismo , Proteína Supressora de Tumor p53/deficiência , Animais , Benzotiazóis/uso terapêutico , Modelos Animais de Doenças , Proteínas da Membrana Plasmática de Transporte de Dopamina/genética , Inibidores Enzimáticos/uso terapêutico , Comportamento Exploratório/efeitos dos fármacos , Comportamento Exploratório/fisiologia , Febre/fisiopatologia , Proteína Glial Fibrilar Ácida/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Mutação/genética , Síndromes Neurotóxicas/tratamento farmacológico , Síndromes Neurotóxicas/fisiopatologia , Substância Negra/efeitos dos fármacos , Substância Negra/metabolismo , Tolueno/análogos & derivados , Tolueno/uso terapêutico , Proteína Supressora de Tumor p53/antagonistas & inibidores , Proteína Supressora de Tumor p53/genética , Tirosina 3-Mono-Oxigenase/metabolismo , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética , Proteína X Associada a bcl-2/metabolismo , Proteínas rho de Ligação ao GTP/metabolismoRESUMO
Traumatic brain injury (TBI) is a major cause of death and disability worldwide. Neuronal apoptosis in the hippocampus has been detected after TBI. The hippocampal dysfunction may result in cognitive deficits in learning, memory, and spatial information processing. Our previous studies demonstrated that a p53 inhibitor, pifithrin-α oxygen analogue (PFT-α (O)), significantly reduced cortical cell death, which is substantial following controlled cortical impact (CCI) TBI, and improved neurological functional outcomes via anti-apoptotic mechanisms. In the present study, we examined the effect of PFT-α (O) on CCI TBI-induced hippocampal cellular pathophysiology in light of this brain region's role in memory. To investigate whether p53-dependent apoptosis plays a role in hippocampal neuronal loss and associated cognitive deficits and to define underlying mechanisms, SD rats were subjected to experimental CCI TBI followed by the administration of PFT-α or PFT-α (O) (2mg/kg, i.v.) or vehicle at 5h after TBI. Magnetic resonance imaging (MRI) scans were acquired at 24h and 7days post-injury to assess evolving structural hippocampal damage. Fluoro-Jade C was used to stain hippocampal sub-regions, including CA1 and dentate gyrus (DG), for cellular degeneration. Neurological functions, including motor and recognition memory, were assessed by behavioral tests at 7days post injury. p53, p53 upregulated modulator of apoptosis (PUMA), 4-hydroxynonenal (4-HNE), cyclooxygenase-IV (COX IV), annexin V and NeuN were visualized by double immunofluorescence staining with cell-specific markers. Levels of mRNA encoding for caspase-3, p53, PUMA, Bcl-2, Bcl-2-associated X protein (BAX) and superoxide dismutase (SOD) were measured by RT-qPCR. Our results showed that post-injury administration of PFT-α and, particularly, PFT-α (O) at 5h dramatically reduced injury volumes in the ipsilateral hippocampus, improved motor outcomes, and ameliorated cognitive deficits at 7days after TBI, as evaluated by novel object recognition and open-field test. PFT-α and especially PFT-α (O) significantly reduced the number of FJC-positive cells in hippocampus CA1 and DG subregions, versus vehicle treatment, and significantly decreased caspase-3 and PUMA mRNA expression. PFT-α (O), but not PFT-α, treatment significantly lowered p53 and elevated SOD2 mRNA expression. Double immunofluorescence staining demonstrated that PFT-α (O) treatment decreased p53, annexin V and 4-HNE positive neurons in the hippocampal CA1 region. Furthermore, PUMA co-localization with the mitochondrial maker COX IV, and the upregulation of PUMA were inhibited by PFT-α (O) after TBI. Our data suggest that PFT-α and especially PFT-α (O) significantly reduce hippocampal neuronal degeneration, and ameliorate neurological and cognitive deficits in vivo via antiapoptotic and antioxidative properties.
Assuntos
Benzotiazóis/uso terapêutico , Lesões Encefálicas Traumáticas/complicações , Transtornos Cognitivos , Tolueno/análogos & derivados , Proteína Supressora de Tumor p53/metabolismo , Aldeídos/metabolismo , Animais , Anexina A5/genética , Anexina A5/metabolismo , Proteínas Reguladoras de Apoptose/metabolismo , Benzotiazóis/química , Benzotiazóis/farmacologia , Encéfalo/diagnóstico por imagem , Lesões Encefálicas Traumáticas/diagnóstico por imagem , Transtornos Cognitivos/diagnóstico por imagem , Transtornos Cognitivos/tratamento farmacológico , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/patologia , Modelos Animais de Doenças , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Comportamento Exploratório/efeitos dos fármacos , Fluoresceínas/metabolismo , Imageamento por Ressonância Magnética , Masculino , Oxigênio , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Reconhecimento Psicológico/efeitos dos fármacos , Fatores de Tempo , Tolueno/química , Tolueno/farmacologia , Tolueno/uso terapêutico , Proteína Supressora de Tumor p53/genéticaRESUMO
Promoting regenerative repair, including neurogenesis and angiogenesis, may provide a new therapeutic strategy for treatment of stroke. P53, a well-documented transcription factor, has been reported to be involved in cerebral ischemia and also serves as an important regulator of vascular endothelial growth factor (VEGF). However, the role of p53 in endogenous regenerative repair after brain ischemia is poorly understood. In this study, we investigated the effects of PFT-α, a specific p53 inhibitor on neurogenesis and angiogenesis improvement and associated signal pathways in rats impaired by cerebral artery occlusion (MCAo). PFT-α induced neuroprotection, reduced infarct volume and neurological functional impairment after ischemic stroke. More importantly, neurogenesis and angiogenesis were greatly enhanced by PFT-α, and accompanied by increased expression of VEGF. Moreover, we got consistent results in neural stem cells (NSCs) isolated from fetal rats. In contrast, application of the anti-VEGF neutralizing antibody (RB-222) partially reversed PFT-α-induced neuroprotection and rescued p53 expression. Noteworthily, inhibition of p53 after ischemic stroke in these rats improved their outcomes via promotion of regenerative repair. In conclusion, PFT-α could serve as a promising therapeutic strategy for ischemic stroke by promoting regenerative repair.
Assuntos
Benzotiazóis/uso terapêutico , Isquemia Encefálica/tratamento farmacológico , Fármacos Neuroprotetores/uso terapêutico , Tolueno/análogos & derivados , Fator A de Crescimento do Endotélio Vascular/fisiologia , Animais , Isquemia Encefálica/patologia , Isquemia Encefálica/fisiopatologia , Proliferação de Células/efeitos dos fármacos , Modelos Animais de Doenças , Técnicas In Vitro , Masculino , Neovascularização Fisiológica/efeitos dos fármacos , Neovascularização Fisiológica/fisiologia , Células-Tronco Neurais/efeitos dos fármacos , Células-Tronco Neurais/patologia , Neurogênese/efeitos dos fármacos , Neurogênese/fisiologia , Ratos , Ratos Sprague-Dawley , Regeneração/efeitos dos fármacos , Regeneração/fisiologia , Transdução de Sinais/efeitos dos fármacos , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/patologia , Acidente Vascular Cerebral/fisiopatologia , Tolueno/uso terapêutico , Proteína Supressora de Tumor p53/antagonistas & inibidores , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidoresRESUMO
Chronic exposure to excessive manganese (Mn) has been known to lead to neuronal loss and a clinical syndrome resembling idiopathic Parkinson's disease (IPD). p53 plays an integral role in the development of various human diseases, including neurodegenerative disorders. However, the role of p53 in Mn-induced neuronal apoptosis and neurological deficits remains obscure. In the present study, we showed that p53 was critically involved in Mn-induced neuronal apoptosis in rat striatum through both transcription-dependent and -independent mechanisms. Western blot and immunohistochemistrical analyses revealed that p53 was remarkably upregulated in the striatum of rats following Mn exposure. Coincidentally, increased level of cleaved PARP, a hallmark of apoptosis, was observed. Furthermore, using nerve growth factor (NGF)-differentiated PC12 cells as a neuronal cell model, we showed that Mn exposure decreased cell viability and induced apparent apoptosis. Importantly, p53 was progressively upregulated, and accumulated in both the nucleus and the cytoplasm. The cytoplasmic p53 had a remarkable distribution in mitochondria, suggesting an involvement of p53 mitochondrial translocation in Mn-induced neuronal apoptosis. In addition, Mn-induced impairment of mitochondrial membrane potential (ΔΨm) could be partially rescued by pretreatment with inhibitors of p53 transcriptional activity and p53 mitochondrial translocation, Pifithrin-α (PFT-α) and Pifithrin-µ (PFT-µ), respectively. Moreover, blockage of p53 activities with PFT-α and PFT-µ significantly attenuated Mn-induced reactive oxidative stress (ROS) generation and mitochondrial H2O2 production. Finally, we observed that pretreatment with PFT-α and PFT-µ ameliorated Mn-induced apoptosis in PC12 cells. Collectively, these findings implicate that p53 transcription-dependent and -independent pathways may play crucial roles in the regulation of Mn-induced neuronal death.
Assuntos
Apoptose/efeitos dos fármacos , Corpo Estriado/efeitos dos fármacos , Intoxicação por Manganês/metabolismo , Mitocôndrias/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Proteína Supressora de Tumor p53/metabolismo , Regulação para Cima/efeitos dos fármacos , Animais , Antídotos/farmacologia , Antídotos/uso terapêutico , Benzotiazóis/farmacologia , Benzotiazóis/uso terapêutico , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Núcleo Celular/patologia , Corpo Estriado/metabolismo , Corpo Estriado/patologia , Citoplasma/efeitos dos fármacos , Citoplasma/metabolismo , Citoplasma/patologia , Masculino , Manganês/química , Manganês/toxicidade , Intoxicação por Manganês/tratamento farmacológico , Intoxicação por Manganês/patologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Proteínas do Tecido Nervoso/antagonistas & inibidores , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Neurônios/patologia , Células PC12 , Transporte Proteico/efeitos dos fármacos , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Sulfonamidas/farmacologia , Sulfonamidas/uso terapêutico , Tolueno/análogos & derivados , Tolueno/farmacologia , Tolueno/uso terapêutico , Proteína Supressora de Tumor p53/antagonistas & inibidores , Proteína Supressora de Tumor p53/genéticaRESUMO
The effect of pifithrin (PFT)-α, a pharmacological inhibitor of p53, on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW 264.7 macrophage-like cells was examined. PFT-α inhibited the production of NO but not tumor necrosis factor (TNF)-α in response to LPS. PFT-α inhibited LPS-induced NO production via reduced expression of an inducible NO synthase (iNOS). Moreover, PFT-α inhibited LPS-induced iNOS expression in p53-silenced cells. PFT-α inhibited the production of interferon (IFN)-ß, characteristic of the MyD88-independent pathway of LPS signaling, whereas it did not affect the activation of nuclear factor (NF)-κB and mitogen-activated protein kinases in the MyD88-dependent pathway. PFT-α inhibited poly I:C-induced NO production whereas it did not inhibit IFN-ß-induced NO production. Further, PFT-α reduced the expression of IFN regulatory factor 3 that leads to the IFN-ß production in the MyD88-independent pathway. The most upstream event impaired by PFT-α was the reduced expression of TNF receptor-associated factor (TRAF) 3 in the MyD88-independent pathway. PFT-α also reduced the in vivo expression of iNOS in the livers of mice injected with LPS. Taken together, PFT-α was suggested to inhibit LPS-induced NO production via impairment of the MyD88-independent pathway and attenuated LPS-mediated inflammatory response.
Assuntos
Benzotiazóis/farmacologia , Lipopolissacarídeos/toxicidade , Macrófagos Peritoneais/efeitos dos fármacos , Fator 88 de Diferenciação Mieloide/metabolismo , Óxido Nítrico/antagonistas & inibidores , Tolueno/análogos & derivados , Proteína Supressora de Tumor p53/antagonistas & inibidores , Animais , Benzotiazóis/administração & dosagem , Benzotiazóis/uso terapêutico , Técnicas de Cultura de Células , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Inativação Gênica , Interferon beta/imunologia , Macrófagos Peritoneais/imunologia , Macrófagos Peritoneais/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Óxido Nítrico/biossíntese , Óxido Nítrico Sintase Tipo II/antagonistas & inibidores , Óxido Nítrico Sintase Tipo II/genética , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Tolueno/administração & dosagem , Tolueno/farmacologia , Tolueno/uso terapêutico , Fator de Necrose Tumoral alfa/imunologia , Proteína Supressora de Tumor p53/genéticaRESUMO
OBJECTIVE: To investigate whether inhibition of mitochondrial p53 association using pifithrin-µ (PFT-µ) represents a potential novel neuroprotective strategy to combat perinatal hypoxic-ischemic (HI) brain damage. METHODS: Seven-day-old rats were subjected to unilateral carotid artery occlusion and hypoxia followed by intraperitoneal treatment with PFT-µ, an inhibitor of p53 mitochondrial association or PFT-α an inhibitor of p53 transcriptional activity. Cerebral damage, sensorimotor and cognitive function, apoptotic pathways (cytosolic cytochrome c, Smac/DIABLO, active caspase 3), and oxidative stress (lipid peroxidation and PARP-1 cleavage) were investigated. RESULTS: PFT-µ treatment completely prevented the HI-induced increase in mitochondrial p53 association at 3 hours and reduced neuronal damage at 48 hours post-HI. PFT-µ had long-term (6-10 weeks post-HI) beneficial effects as sensorimotor and cognitive outcome improved and infarct size was reduced by ~79%. Neuroprotection by PFT-µ treatment was associated with strong inhibition of apoptotic pathways and reduced oxidative stress. Unexpectedly, PFT-µ also inhibited HI-induced upregulation of p53 target genes. However, the neuroprotective effect of inhibiting only p53 transcriptional activity by PFT-α was significantly smaller and did not involve reduced oxidative stress. INTERPRETATION: We are the first to show that prevention of mitochondrial p53 association by PFT-µ strongly improves functional outcome and decreases lesion size after neonatal HI. PFT-µ not only inhibits mitochondrial release of cytochrome c, but also inhibits oxidative stress. We propose that as a consequence nuclear accumulation of p53 and transcription of proapoptotic target genes are prevented. In conclusion, targeting p53 mitochondrial association by PFT-µ may develop into a novel and powerful neuroprotective strategy.
Assuntos
Benzotiazóis/farmacologia , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Hipóxia-Isquemia Encefálica/prevenção & controle , Fármacos Neuroprotetores/farmacologia , Tolueno/análogos & derivados , Proteína Supressora de Tumor p53/metabolismo , Animais , Animais Recém-Nascidos , Apoptose/fisiologia , Benzotiazóis/uso terapêutico , Biomarcadores/metabolismo , Encéfalo/patologia , Hipóxia-Isquemia Encefálica/patologia , Mitocôndrias/efeitos dos fármacos , Fármacos Neuroprotetores/uso terapêutico , Estresse Oxidativo , Ratos , Ratos Wistar , Tolueno/farmacologia , Tolueno/uso terapêutico , Resultado do Tratamento , Proteína Supressora de Tumor p53/antagonistas & inibidoresRESUMO
Reducing cancer incidence and mortality by use of cancer-chemopreventive agents is an important goal. We have established an in vitro bioassay that is able to screen large numbers of candidate chemicals that are positive for prevention of inflammation-related carcinogenesis. To accomplish this we have added candidate chemicals or vehicles and freshly isolated, fluorescent dye-labeled inflammatory cells that were overlaid on TNF-alpha-stimulated mouse endothelial cells in a 96-well plate. Inhibition of inflammatory cell attachment to the endothelial cells by the chemicals was quantified by the intensity of fluorescence from the adherent inflammatory cells after removing unattached cells. Using this assay, we selected two chemicals, auraptene and turmerones, for further study. As an in vivo test, diets containing these test chemicals were administered to mice with a piece of foreign body, gelatin sponge, that had been implanted to cause inflammation, and we found that the number of inflammatory cells that infiltrated into the subcutaneously implanted gelatin sponge was reduced compared to that found in the mice fed with a control diet. Moreover, diets containing either of the two chemicals prevented inflammation-based carcinogenesis in a mouse model. We found that the compounds reduced not only the number of infiltrating cells but also the expression of inducible nitric oxide synthase (iNOS) or formation of 8-hydroxy-2'-deoxyguanine (8-OHdG) in the infiltrated cells. Moreover, both compounds but not controls sustained the reducing activity in the inflammatory lesion, and this finding was confirmed by using non-invasive in vivo electron spin resonance. The newly established in vitro screening assay will be useful for finding biologically effective chemopreventive agents against inflammation-related carcinogenesis.
Assuntos
Bioensaio/métodos , Células Endoteliais/efeitos dos fármacos , Imuno-Histoquímica/métodos , Inflamação/prevenção & controle , Animais , Anticarcinógenos/uso terapêutico , Adesão Celular , Cumarínicos/administração & dosagem , Cumarínicos/uso terapêutico , Células Endoteliais/imunologia , Feminino , Fibrossarcoma/induzido quimicamente , Fibrossarcoma/tratamento farmacológico , Fluorescência , Cetonas/administração & dosagem , Cetonas/uso terapêutico , Metilcolantreno/toxicidade , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias Experimentais , Óleos de Plantas/uso terapêutico , Sesquiterpenos , Tolueno/administração & dosagem , Tolueno/análogos & derivados , Tolueno/uso terapêutico , Células Tumorais Cultivadas , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
BACKGROUND: The mechanism of cerebral vasospasm following subarachnoid haemorrhage (SAH) is not understood. Here, we hypothesized that apoptosis of endothelial cells induced by p53 and its target gene em dash p53 upregulated modulator of apoptosis (PUMA) played an important role in development of cerebral vasospasm. We also observed the effects of a p53 inhibitor, pifithrin-alpha (PFT-alpha), on reducing the expression of p53 and PUMA, consequently decreasing the apoptosis of endothelial cells and alleviating cerebral vasospasm. METHODS: Male Sprague-Dawley rats weighing 300-350 g were randomly divided into five groups: a control group (sham surgery), a SAH group, a SAH+dimethyl sulfoxide (DMSO) group, a SAH + PFT-alpha (0.2 mg/kg) group and a SAH + PFT-alpha (2.0 mg/kg) group. PFT-alpha was injected intraperitoneally immediately after SAH. Rats were sacrificed 24 hours after SAH. Western blot and immunohistochemical staining were used to detect the levels of p53, PUMA and caspase-3 protein. In addition, mortality and neurological scores were assessed for each group. Statistical significance was assured by analysis of variance performed in one way ANOVA followed by the Tukey test. The neurological and mortality scores were analyzed by Dunn's method and Fisher exact test, respectively. RESULTS: After SAH, Western blot and immunohistochemical staining showed the levels of p53, PUMA and caspase-3 in the endothelial cells and the numbers of TdT mediated dUTP nick end labelling (TUNEL) positive endothelial cells were all significantly increased in the basilar arteries (P<0.05), but significantly reduced by PFT-alpha (P<0.05). These changes were accompanied by increasing diameters and declining wall thickness of basilar arteries (P<0.05), as well as reduced mortality and neurological deficits of the rats (P<0.05). CONCLUSIONS: PFT-alpha could protect cerebral vessels from development of vasospasm and improve neurological outcome as well as reduce the mortality via suppressing apoptosis induced by p53 in the endothelial cells of cerebral vessels.
Assuntos
Apoptose/efeitos dos fármacos , Benzotiazóis/uso terapêutico , Células Endoteliais/efeitos dos fármacos , Hemorragia Subaracnóidea/tratamento farmacológico , Tolueno/análogos & derivados , Vasoespasmo Intracraniano/prevenção & controle , Animais , Benzotiazóis/farmacologia , Western Blotting , Modelos Animais de Doenças , Células Endoteliais/patologia , Masculino , Ratos , Ratos Sprague-Dawley , Hemorragia Subaracnóidea/complicações , Hemorragia Subaracnóidea/patologia , Hemorragia Subaracnóidea/fisiopatologia , Tolueno/farmacologia , Tolueno/uso terapêutico , Proteína Supressora de Tumor p53/fisiologiaRESUMO
OBJECTIVE: To investigate the dose-effect relationship of para-toluenesulfonamide (PTS) for treatment of hepatocellular carcinoma in rats. METHODS: Forty-two SD rats bearing subcutaneous transplanted hepatocellular carcinoma were randomly divided into 6 groups (n=7), in which 0.02, 0.04, 0.06, 0.08, and 0.10 ml PTS and 0.10 ml normal saline were injected into the tumor, respectively. All of the rats were executed 24 h after the injection to observe the pathological changes in the tumor. RESULTS: In rats with saline injection, the tumor tissues exhibited no obvious changes and the tumor cells retained the active proliferation. PTS, in contrast, caused coagulation necrosis of the tumor tissue, and the necrotic area expanded with the increase of the injected doses. The necrotic volume of the tumor was in roughly linear correlation with the dose of PTS injected, with the linear regression equation of V (cm(3))=-0.018+2.595Y (where V represents tumor necrosis volume, and Y the injected dose of PTS). CONCLUSION: The dose-effect relationship of PTS is roughly linear, and the PTS dose for injection can be estimated according to the diameter of the tumor.
Assuntos
Antineoplásicos/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , Sulfonamidas/uso terapêutico , Tolueno/análogos & derivados , Animais , Carcinoma Hepatocelular/patologia , Proliferação de Células , Relação Dose-Resposta a Droga , Necrose , Ratos , Ratos Sprague-Dawley , Tolueno/uso terapêuticoRESUMO
Inactivation of p53 function, which frequently occurs in tumors, can significantly modulate tumor cell sensitivity to radiation and chemotherapeutic drugs. However, in addition to acting on malignant cells, anticancer agents act on the cells of tumor stroma, causing activation of a p53 response. The effect of this response on treatment outcome has been the subject of the present study. Tumors with p53-deficient stroma were generated using mouse tumorigenic packaging cells that produce a p53 inhibitory retrovirus, encoding a dominant-negative p53 mutant. Tumors maintaining wild-type p53 in their stroma were formed by cells of similar origin but deficient in retroviral production due to the deletion of the packaging signal in the retroviral vector. Comparison of these tumor models, differing only in p53 status of their stromas, showed that tumors with p53-deficient stroma were significantly more sensitive to experimental chemotherapy and radiotherapy. A similar effect was achieved when anticancer treatment was combined with pharmacologic suppression of p53 by the cyclic form of pifithrin alpha, a small-molecule inhibitor of p53. Potentiation of the anticancer effect of chemotherapy and radiotherapy by p53 suppression in the tumor stroma is likely to be due to the increased sensitivity of p53-deficient endothelium to genotoxic stress as shown both in cell culture and in experimental tumors. Thus, reversible pharmacologic suppression of p53 may be a viable approach to improving anticancer treatment via an enhanced antiangiogenic effect of chemotherapy and radiotherapy.
Assuntos
Inibidores da Angiogênese/uso terapêutico , Antineoplásicos Alquilantes/uso terapêutico , Benzotiazóis/uso terapêutico , Carcinoma Pulmonar de Lewis/terapia , Ciclofosfamida/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Imidazóis/uso terapêutico , Radiossensibilizantes/uso terapêutico , Tiazóis/uso terapêutico , Tolueno/análogos & derivados , Proteína Supressora de Tumor p53/antagonistas & inibidores , Inibidores da Angiogênese/farmacologia , Animais , Antineoplásicos Alquilantes/farmacologia , Benzotiazóis/farmacologia , Benzotiazóis/toxicidade , Carcinoma Pulmonar de Lewis/tratamento farmacológico , Carcinoma Pulmonar de Lewis/radioterapia , Linhagem Celular Transformada , Ciclofosfamida/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Células Endoteliais/efeitos da radiação , Fibroblastos , Imidazóis/farmacologia , Imidazóis/toxicidade , Camundongos , Camundongos Endogâmicos C57BL , Células NIH 3T3 , Conformação Proteica , Radiossensibilizantes/farmacologia , Radiossensibilizantes/toxicidade , Ratos , Células Estromais/efeitos dos fármacos , Células Estromais/efeitos da radiação , Tiazóis/farmacologia , Tiazóis/toxicidade , Tolueno/farmacologia , Tolueno/uso terapêutico , Tolueno/toxicidade , Transdução Genética , Proteína Supressora de Tumor p53/química , Proteína Supressora de Tumor p53/genéticaRESUMO
p53-dependent apoptosis contributes to the side effects of cancer treatment, and genetic or pharmacological inhibition of p53 function can increase normal tissue resistance to genotoxic stress. It has recently been shown that p53 can induce apoptosis through a mechanism that does not depend on transactivation but instead involves translocation of p53 to mitochondria. To determine the impact of this p53 activity on normal tissue radiosensitivity, we isolated a small molecule named pifithrin-mu (PFTmu, 1) that inhibits p53 binding to mitochondria by reducing its affinity to antiapoptotic proteins Bcl-xL and Bcl-2 but has no effect on p53-dependent transactivation. PFTmu has a high specificity for p53 and does not protect cells from apoptosis induced by overexpression of proapoptotic protein Bax or by treatment with dexamethasone (2). PFTmu rescues primary mouse thymocytes from p53-mediated apoptosis caused by radiation and protects mice from doses of radiation that cause lethal hematopoietic syndrome. These results indicate that selective inhibition of the mitochondrial branch of the p53 pathway is sufficient for radioprotection in vivo.
Assuntos
Raios gama/efeitos adversos , Mitocôndrias/metabolismo , Lesões Experimentais por Radiação/prevenção & controle , Protetores contra Radiação/uso terapêutico , Tiazóis/uso terapêutico , Tolueno/análogos & derivados , Proteína Supressora de Tumor p53/antagonistas & inibidores , Animais , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/metabolismo , Benzotiazóis , Linhagem Celular , Dexametasona/farmacologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ligação Proteica , Transporte Proteico , Lesões Experimentais por Radiação/metabolismo , Lesões Experimentais por Radiação/patologia , Protetores contra Radiação/química , Protetores contra Radiação/farmacologia , Tiazóis/química , Tiazóis/farmacologia , Timo/efeitos dos fármacos , Timo/metabolismo , Timo/patologia , Tolueno/química , Tolueno/farmacologia , Tolueno/uso terapêutico , Ativação Transcricional , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Raios Ultravioleta/efeitos adversosRESUMO
BACKGROUND AND PURPOSE: Despite intensive research efforts, the etiology of vasospasm (sustained constriction of the cerebral vessels) remains unknown. In this study, we investigated the role of p53-induced apoptosis in the vasculature at 24 and 72 hours. To completely examine the apoptotic cascades, key proteins of the caspase-dependent, -independent and mitochondrial pathways were examined. METHODS: In this study, adult rats were divided into 3 groups: sham (n=21), nontreatment (subarachnoid hemorrhage [SAH]+dimethyl sulfoxide; n=42), and treatment (SAH+pifithrin-alpha) (n=42) groups. Each animal in the SAH group underwent a surgical procedure to induce SAH, and the basilar artery was harvested at 24 and 72 hours for analysis. RESULTS: We found severe vasospasm at the 24-hour time point, which persisted to 72 hours. Furthermore, we found that the markers of the apoptotic cascades rose significantly at the 24-hour time point but had dissipated by 72 hours. However, the neurological outcome and mortality scores improved at the 72-hour time point. CONCLUSIONS: Apoptosis, and in particular p53, may play an important role in the etiology of vasospasm with relation to SAH, and in this model, vasospasm persisted to 72 hours, despite the fact that apoptosis does not.