RESUMEN
The discovery of microRNAs (miRNAs) in 1993 has challenged the dogma of gene expression regulation. MiRNAs affect most of cellular processes from metabolism, through cell proliferation and differentiation, to cell death. In cancer, deregulated miRNA expression leads to tumor development and progression by promoting acquisition of cancer hallmark traits. The multi-target action of miRNAs, which enable regulation of entire signaling networks, makes them attractive tools for the development of anti-cancer therapies. Hence, supplementing downregulated miRNA by synthetic oligonucleotides or silencing overexpressed miRNAs through artificial antagonists became a common strategy in cancer research. However, the ultimate success of miRNA therapeutics will depend on solving pharmacokinetic and targeted delivery issues. The development of a number of nanocarrier-based platforms holds significant promises to enhance the cell specific controlled delivery and safety profile of miRNA-based therapies. In this review, we provide among the most comprehensive assessments to date of promising nanomedicine platforms that have been tested preclinically, pertaining to the treatment of selected solid tumors including lung, liver, breast, and glioblastoma tumors as well as endocrine malignancies. The future challenges and potential applications in clinical oncology are discussed.
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MicroRNAs (miRNAs) are small non-coding RNAs that are involved in the regulation of major pathways in eukaryotic cells through their binding to and repression of multiple mRNAs. With high-throughput methodologies, various outcomes can be measured that produce long lists of miRNAs that are often difficult to interpret. A common question is: after differential expression or phenotypic screening of miRNA mimics, which miRNA should be chosen for further investigation? Here, we present miRViz (http://mirviz.prabi.fr/), a webserver application designed to visualize and interpret large miRNA datasets, with no need for programming skills. MiRViz has two main goals: (i) to help biologists to raise data-driven hypotheses and (ii) to share miRNA datasets in a straightforward way through publishable quality data representation, with emphasis on relevant groups of miRNAs. MiRViz can currently handle datasets from 11 eukaryotic species. We present real-case applications of miRViz, and provide both datasets and procedures to reproduce the corresponding figures. MiRViz offers rapid identification of miRNA families, as demonstrated here for the miRNA-320 family, which is significantly exported in exosomes of colon cancer cells. We also visually highlight a group of miRNAs associated with pluripotency that is particularly active in control of a breast cancer stem-cell population in culture.
Asunto(s)
MicroARNs/metabolismo , Programas Informáticos , Neoplasias de la Corteza Suprarrenal/genética , Neoplasias de la Corteza Suprarrenal/metabolismo , Neoplasias de la Corteza Suprarrenal/mortalidad , Carcinoma Corticosuprarrenal/genética , Carcinoma Corticosuprarrenal/metabolismo , Carcinoma Corticosuprarrenal/mortalidad , Animales , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Neoplasias del Colon/genética , Neoplasias del Colon/metabolismo , Conjuntos de Datos como Asunto , Exosomas/metabolismo , Femenino , Humanos , Internet , Ratones , MicroARNs/genética , Células Madre Neoplásicas/metabolismoRESUMEN
We have previously identified serum miR-483-5p as a preoperative diagnosis and prognosis biomarker for adrenocortical cancer (ACC). Here, we aimed to determine whether circulating miR-483-5p levels measured 3 months post-operatively distinguished patients with good prognosis (no recurrence for at least 3 years; NR3yrs) from patients with poor prognosis (recurrence or death within 3 years after surgery; R < 3yrs). We conducted a single-center retrospective analysis using sera from 48 patients with ACC that were initially non-metastatic and treated by surgery. Sera sampled within 3 months after surgery were available in 26 patients. MiR-483-5p absolute circulating levels were measured using quantitative PCR. Thirteen patients showed a recurrence before 3 years (=R < 3yrs). Thirteen patients showed no recurrence within 3 years, including 11 patients with a follow-up longer than 3 years (=NR3yrs). Serum miR-483-5p levels were higher in R < 3yrs than in NR3yrs: 1,541,990 ± 428,377 copies/mL vs. 388,457 ± 62,169 copies/mL (p = 0.002). Receiver operating characteristic analysis showed that a value of 752,898 copies/mL distinguished R < 3yrs from NR3yrs with 61.5% sensitivity (CI 31.6-86.1) and 100% specificity (CI 71.5-100) with an area under the curve of 0.853. Patients with a value below this threshold had a significantly longer recurrence-free and overall survival. In multivariate analysis, miR-483-5p provided the single best prognostic value for recurrence-free survival (RFS) (hazard ratio (HR) for recurrence 5.98, p < 0.011) but not for overall survival. Our study suggests that serum miR-483-5p is a potent early post-operative biomarker for ACC prognosis that might be a better predictor of RFS than currently used markers.
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Altered expression of regulatory RNA-binding proteins (RBPs) in cancer leads to abnormal expression of mRNAs encoding many factors involved in cancer hallmarks. While conventional anticancer therapies usually target one pathway at a time, targeting key RBP would affect multiple genes and thus overcome drug resistance. Among the Tristetraprolin family of RBP, TIS11b/BRF1/ZFP36L1 mediates mRNA decay through binding to Adenylate/Uridylate (AU-rich elements) in mRNA 3'-untranslated region and recruitment of mRNA degradation enzymes. Here, we show that TIS11b is markedly underexpressed in three breast cancer cell lines, as well as in breast tumor samples. We hypothesized that restoring intracellular TIS11b levels could impair cancer cell phenotypic traits. We thus generated a derivative of TIS11b called R9-ZnCS334D, by combining N-terminal domain deletion, serine-to-aspartate substitution at position 334 to enhance the function of the protein and fusion to the cell-penetrating peptide polyarginine R9. R9-ZnCS334D not only blunted secretion of vascular endothelial growth factor (VEGF) but also inhibited proliferation, migration, invasion, and anchorage-independent growth of murine 4T1 or human MDA-MB-231 breast cancer cells. Moreover, R9-ZnCS334D prevented endothelial cell organization into vessel-like structures, suggesting that it could potentially target various cell types within the tumor microenvironment. In vivo, injection of R9-ZnCS334D in 4T1 tumors impaired tumor growth, decreased tumor hypoxia, and expression of the epithelial-to-mesenchymal transition (EMT) markers Snail, Vimentin, and N-cadherin. R9-ZnCS334D also hindered the expression of chemokines and proteins involved in cancer-related inflammation and invasion including Fractalkine (CX3CL1), SDF-1 (CXCL12), MCP-1 (CCL2), NOV (CCN3), and Pentraxin-3 (PTX3). Collectively, our data indicate that R9-ZnCS334D counteracts multiple traits of breast cancer cell aggressiveness and suggest that this novel protein could serve as the basis for innovative multi-target therapies in cancer.
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Elementos Ricos en Adenilato y Uridilato/genética , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Carcinogénesis/genética , Estabilidad del ARN , Factores Asociados con la Proteína de Unión a TATA/fisiología , Animales , Células COS , Carcinogénesis/metabolismo , Células Cultivadas , Chlorocebus aethiops , Femenino , Mutación con Ganancia de Función/fisiología , Regulación Neoplásica de la Expresión Génica , Células Endoteliales de la Vena Umbilical Humana , Humanos , Ratones , Ratones Endogámicos BALB C , Isoformas de Proteínas/genética , Isoformas de Proteínas/fisiología , Estabilidad del ARN/genética , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/farmacología , Factores Asociados con la Proteína de Unión a TATA/genética , Dedos de Zinc/genéticaRESUMEN
Organophosphorus nerve agents still represent a serious risk to human health. In the French armed forces, the current emergency treatment against OP intoxications is a fully licensed wet-dry dual-chambered autoinjector (Ineurope ®), that contains pralidoxime methylsulfate (2-PAM) to reactivate inhibited acetylcholinesterase (AChE), atropine sulfate (AS) and avizafone chlorhydrate (AVZ). While this treatment is effective against several of the known nerve agents, it shows little efficacy against the Russian VX (VR), one of the most toxic compounds. HI-6 dimethanesulfonate (HI-6 DMS) is an oxime able to reactivate in vitro and in vivo VR-inhibited AChE. To confirm the superiority of HI-6 DMS towards 2-PAM prior to licensing, we compared the two 3-drug-combinations (HI-6 vs 2-PAM, 33 and 18 mg/kg respectively, equimolar doses; AS/AVZ 0.25/0.175 mg/kg respectively) in VR-poisoned cynomolgus macaques, the model required by the French drug regulatory agency. In parallel we performed HI-6 pharmacokinetics analysis using a one compartment model. A better efficacy of the HI-6 DMS combination was clearly observed: up to 5 LD50 of VR (i.m.), a single administration of the HI-6 DMS combination, shortly after the onset of clinical signs, prevented death of the four intoxicated animals. Conversely 2-PAM only prevented death in one out of three subjects exposed to the same amount of VR. As expected with V agents, reinhibition of blood AChE was observed but without any apparent impact on the clinical recovery of the animals. A single administration of the HI-6 DMS combination was still but partially effective at 15 LD50 of VR, allowing a 50% survival rate.
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Inhibidores de la Colinesterasa/envenenamiento , Reactivadores de la Colinesterasa/uso terapéutico , Agentes Nerviosos/envenenamiento , Compuestos Organotiofosforados/envenenamiento , Compuestos de Pralidoxima/uso terapéutico , Animales , Análisis de los Gases de la Sangre , Temperatura Corporal/efectos de los fármacos , Reactivadores de la Colinesterasa/farmacocinética , Colinesterasas/sangre , Frecuencia Cardíaca/efectos de los fármacos , Dosificación Letal Mediana , Macaca fascicularis , Masculino , Actividad Motora/efectos de los fármacos , Midriasis/inducido químicamente , Midriasis/patología , Oximas/farmacocinética , Oximas/uso terapéutico , Compuestos de Pralidoxima/farmacocinética , Compuestos de Piridinio/farmacocinética , Compuestos de Piridinio/uso terapéutico , Tasa de SupervivenciaRESUMEN
Adrenocortical carcinoma (ACC) is a tumor with poor prognosis in which overexpression of a panel of microRNAs has been associated with malignancy but a very limited number of investigations on their role in ACC pathogenesis have been conducted. We examined the involvement of miR-483-5p and miR-139-5p in adrenocortical cancer aggressiveness. Using bioinformatics predictions and mRNA/miRNA expression profiles, we performed an integrated analysis to identify inversely correlated miRNA-mRNA pairs in ACC. We identified N-myc downstream-regulated gene family members 2 and 4 (NDRG2 and NDRG4) as targets of miR-483-5p and miR-139-5p, respectively. NDRG2 and NDRG4 expressions were inversely correlated respectively with miR-483-5p and miR-139-5p levels in aggressive ACC samples from two independent cohorts of 20 and 44 ACC. Moreover, upregulation of miR-139-5p and downregulation of NDRG4 demonstrated a striking prognostic value. A direct interaction between miR-483-5p or miR-139-5p and their targets was demonstrated in reporter assays. Downregulation of miR-483-5p or miR-139-5p in the ACC cell lines NCI-H295R and SW13 increased NDRG2 or NDRG4 mRNA and protein expression, compromised adrenocortical cancer cell invasiveness and anchorage-independent growth. MiR-483-5p or miR-139-5p overexpression and NDRG2 or NDRG4 inhibition produce similar changes, which are rescued by NDRG2 or NDRG4 ectopic expression. We established that key factors mediating epithelial-to-mesenchymal transition are downstream effectors of miR-483-5p/NDRG2 and miR-139-5p/NDRG4 pathways. Collectively, our data show for the first time that miR-483-5p/NDRG2 and miR-139-5p/NDRG4 axes promote ACC aggressiveness, with potential implications for prognosis and therapeutic interventions in adrenocortical malignancies.
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Neoplasias de la Corteza Suprarrenal/genética , Neoplasias de la Corteza Suprarrenal/patología , Regulación Neoplásica de la Expresión Génica , Genes myc , MicroARNs/fisiología , Familia de Multigenes , Regiones no Traducidas 3' , Apoptosis/fisiología , Adhesión Celular/fisiología , Ciclo Celular/fisiología , Línea Celular Tumoral , Proliferación Celular/fisiología , Regulación hacia Abajo , Transición Epitelial-Mesenquimal , Células HEK293 , Humanos , MicroARNs/genética , Proteínas Musculares/genética , Proteínas Musculares/metabolismo , Estadificación de Neoplasias , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Pronóstico , ARN Mensajero/genética , Proteínas Supresoras de Tumor/genética , Proteínas Supresoras de Tumor/metabolismo , Regulación hacia ArribaRESUMEN
Neuronal Per-Arnt-Sim (PAS) domain protein 4 (Npas4) is a key protein that intervenes in GABA synapse scaling and neurotrophicity enhancing. Since GABA and neurotrophicity are implicated in stress response and Npas4-deficient rodents exhibit behavioral alterations, an investigation was designed in rats to verify whether stress-induced spontaneous hippocampus Npas4 mRNA expression would be associated with specific patterns of stress response. The rats were exposed to one of three stressor levels: no stress (CTL, nâ¯=â¯15), exposure to a footshock apparatus (Sham, S, nâ¯=â¯40) and footshock (F, nâ¯=â¯80). After stress exposure the S and F rats were tested in an activity cage, and subsequently in an elevated plus maze (EPM), just prior to the sacrifice. Using cluster analysis, the animals already assigned to a stress level were also distributed into 2 subgroups depending on their Npas4 mRNA levels. The low (L) and high (H) Npas4 expression subgroups were identified in the S and F groups, the CTL group being independent of the Npas4 levels. The Npas4 effect was studied through the interaction between stress (S and F) and Npas4 level (L and H). The biological stress response was similar in H and L rats, except blood corticosterone that was slightly lower in the H rats. The H rats were more active in the actimetry cage and presented higher levels of exploration in the EPM. They also exhibited higher hippocampus activation, as assessed by the c-fos, Egr1 and Arc mRNA levels. Therefore high Npas4 expression favors stress management.
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Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Regulación de la Expresión Génica/fisiología , Hipocampo/metabolismo , ARN Mensajero/metabolismo , Estrés Fisiológico/fisiología , Estrés Psicológico/patología , Análisis de Varianza , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Glucemia , Corticosterona/sangre , Proteínas del Citoesqueleto/genética , Proteínas del Citoesqueleto/metabolismo , Electrochoque/métodos , Femenino , Insulina/sangre , Locomoción/fisiología , Masculino , Aprendizaje por Laberinto/fisiología , Actividad Motora/fisiología , Subunidad p50 de NF-kappa B/genética , Subunidad p50 de NF-kappa B/metabolismo , Proteínas del Tejido Nervioso/genética , Proteínas del Tejido Nervioso/metabolismo , Neurotransmisores/sangre , Proteínas Oncogénicas v-fos/genética , Proteínas Oncogénicas v-fos/metabolismo , Ratas , Ratas Sprague-DawleyRESUMEN
TPA-inducible sequence 11b/butyrate response factor 1 (TIS11b/BRF1) belongs to the tristetraprolin (TTP) family of zinc-finger proteins, which bind to mRNAs containing AU-rich elements in their 3'-untranslated region and target them for degradation. Regulation of TTP family function through phosphorylation by p38 MAP kinase and Akt/protein kinase B signaling pathways has been extensively studied. In contrast, the role of cAMP-dependent protein kinase (PKA) in the control of TTP family activity in mRNA decay remains largely unknown. Here we show that PKA activation induces TIS11b gene expression and protein phosphorylation. Site-directed mutagenesis combined with kinase assays and specific phosphosite immunodetection identified Ser-54 (S54) and Ser-334 (S334) as PKA target amino acids in vitro and in vivo. Phosphomimetic mutation of the C-terminal S334 markedly increased TIS11b half-life and, unexpectedly, enhanced TIS11b activity on mRNA decay. Examination of protein-protein interactions between TIS11b and components of the mRNA decay machinery revealed that mimicking phosphorylation at S334 enhances TIS11b interaction with the decapping coactivator Dcp1a, while preventing phosphorylation at S334 potentiates its interaction with the Ccr4-Not deadenylase complex subunit Cnot1. Collectively our findings establish for the first time that cAMP-elicited phosphorylation of TIS11b plays a key regulatory role in its mRNA decay-promoting function.
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Factores Asociados con la Proteína de Unión a TATA/genética , Factores Asociados con la Proteína de Unión a TATA/metabolismo , Regiones no Traducidas 3' , Animales , Células COS , Técnicas de Cultivo de Célula , Chlorocebus aethiops , AMP Cíclico , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Endorribonucleasas/metabolismo , Humanos , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Mutagénesis Sitio-Dirigida , Fosforilación , Dominios y Motivos de Interacción de Proteínas , Proteínas con Motivos de Reconocimiento de ARN/metabolismo , Estabilidad del ARN/fisiología , ARN Mensajero/metabolismo , Proteínas de Unión al ARN/metabolismo , Transactivadores/metabolismo , Tristetraprolina/metabolismoRESUMEN
OBJECTIVES: An increased reactivity to the environment is observed in Post-Traumatic Stress Disorder (PTSD). It would be related to impairment of the Gamma Amino Butyric Acid (GABA) neurotransmission. The study aimed to evaluate plasma GABA concentration as a candidate for PTSD severity biomarker. METHODS: This hypothesis was studied in 17 PTSD patients and 17 healthy Controls using classic and emotional Stroop paradigms. Plasma GABA concentrations were assessed before and after both Stroop tests to evaluate GABA basal tone and GABA reactivity (change in GABAp), respectively. RESULTS: During baseline, PTSD had lower plasma GABA concentrations than the Controls. After the Stroop conflicts GABA reactivity was also lower in PTSD than in the Controls. The GABA baseline tone was negatively correlated with the severity of the PTSD symptoms. This relation was only marginally observed for GABA reactivity. The results produced a trend due to the small size of the sample compared to the number of statistical results given. CONCLUSION: Altogether, the reduced GABA concentration observed in PTSD could be considered as a possible biomarker for PTSD severity.
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Trastornos por Estrés Postraumático/sangre , Ácido gamma-Aminobutírico/sangre , Adulto , Biomarcadores/sangre , Estudios de Casos y Controles , Emociones/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Personal Militar/psicología , Enfermedades Profesionales/sangre , Enfermedades Profesionales/psicología , Índice de Severidad de la Enfermedad , Test de StroopRESUMEN
Exposure to organophosphorus (OP) compounds, such as pesticides and the chemical warfare agents (soman and sarin), respectively represents a major health problem and a threat for civilian and military communities. OP poisoning may induce seizures, status epilepticus and even brain lesions if untreated. We recently proved that a combination of atropine sulfate and ketamine, a glutamatergic antagonist, was effective as an anticonvulsant and neuroprotectant in mice and guinea-pigs exposed to soman. Since OP exposure may also occur in conditions of heat strain due to climate, wearing of protective gears or physical exercise, we previously demonstrated that ketamine/atropine association may be used in a hot environment without detrimental effects. In the present study, we assess soman toxicity and evaluate the effects of the ketamine/atropine combination on soman toxicity in a warm thermoneutral environment. Male Wistar rats, exposed to 31°C (easily reached under protective equipments), were intoxicated by soman and treated with an anesthetic dose of ketamine combined with atropine sulfate. Body core temperature and spontaneous locomotor activity were continuously monitored using telemetry. At the end of the warm exposure, blood chemistry and brain mRNA expression of some specific genes were measured. In soman-intoxicated animals, metabolic and genic modifications were related to convulsions rather than to soman intoxication by itself. In the warm environment, ketamine/atropine combination did not produce any side-effect on the assessed variables. Furthermore, the ketamine/atropine combination exhibited beneficial therapeutic effects on soman-intoxicated rats such as a limitation of convulsion-induced hyperthermia and of the increase in some blood chemistry markers.
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Anticonvulsivantes/uso terapéutico , Atropina/uso terapéutico , Sustancias para la Guerra Química/toxicidad , Epilepsia/inducido químicamente , Epilepsia/tratamiento farmacológico , Ketamina/uso terapéutico , Soman/toxicidad , Animales , Temperatura Corporal/efectos de los fármacos , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Lesiones Encefálicas/inducido químicamente , Lesiones Encefálicas/tratamiento farmacológico , Colinesterasas/sangre , Corticosterona/sangre , Modelos Animales de Enfermedad , Quimioterapia Combinada , Fiebre/inducido químicamente , Fiebre/tratamiento farmacológico , Regulación de la Expresión Génica/efectos de los fármacos , Masculino , Actividad Motora/efectos de los fármacos , Ratas , Ratas Wistar , Proteínas Ribosómicas/genética , Proteínas Ribosómicas/metabolismo , Factores de TiempoRESUMEN
In case of a mass casualty radiation event, there is a need to distinguish total-body irradiation (TBI) and partial-body irradiation (PBI) to concentrate overwhelmed medical resources to the individuals that would develop an acute radiation syndrome (ARS) and need hematologic support (i.e., mostly TBI victims). To improve the identification and medical care of TBI versus PBI individuals, reliable biomarkers of exposure could be very useful. To investigate this issue, pairs of baboons (n = 18) were exposed to different situations of TBI and PBI corresponding to an equivalent of either 5 Gy 60Co gamma irradiation (5 Gy TBI; 7.5 Gy left hemibody/2.5 right hemibody TBI; 5.55 Gy 90% PBI; 6.25 Gy 80% PBI; 10 Gy 50% PBI, 15 Gy 30% PBI) or 2.5 Gy (2.5 Gy TBI; 5 Gy 50% PBI). More than fifty parameters were evaluated before and after irradiation at several time points up to 200 days. A partial least square discriminant analysis showed a good distinction of TBI from PBI situations that were equivalent to 5 Gy. Furthermore, all the animals were pooled in two groups, TBI (n = 6) and PBI (n = 12), for comparison using a logistic regression and a non parametric statistical test. Nine plasmatic biochemical markers and most of hematological parameters turned out to discriminate between TBI and PBI animals during the prodromal phase and the manifest illness phase. The most significant biomarkers were aspartate aminotransferase, creatine kinase, lactico dehydrogenase, urea, Flt3-ligand, iron, C-reactive protein, absolute neutrophil count and neutrophil-to-lymphocyte ratio for the early period, and Flt3-ligand, iron, platelet count, hemoglobin, monocyte count, absolute neutrophil count and neutrophil-to-lymphocyte ratio for the ARS phase. These results suggest that heterogeneity could be distinguished within a range of 2.5 to 5 Gy TBI.
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Biomarcadores/sangre , Modelos Animales , Traumatismos Experimentales por Radiación/sangre , Irradiación Corporal Total/métodos , Animales , Aspartato Aminotransferasas/sangre , Proteína C-Reactiva/metabolismo , Creatina Quinasa/sangre , Rayos gamma , Humanos , Hierro/sangre , Recuento de Leucocitos , Masculino , Proteínas de la Membrana/sangre , Papio , Dosis de Radiación , Traumatismos Experimentales por Radiación/diagnóstico , Traumatismos Experimentales por Radiación/etiología , Monitoreo de Radiación/instrumentación , Monitoreo de Radiación/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Urea/sangre , Irradiación Corporal Total/efectos adversosRESUMEN
The evolution of organ damage following extensive high-dose irradiation remains largely unexplored and needs further investigation. Wistar rats [with or without partial bone marrow protection (â¼20%)] were irradiated at lethal gamma-ray doses (12, 14, and 16 Gy) and received antibiotic support. While total-body-irradiated rats did not survive, bone marrow protection (achieved by protecting hind limbs behind a lead wall) combined with antibiotic support allowed survival of 12-Gy and 14-Gy irradiated rats for more than 3 mo, with a late phase of body weight loss and altered clinical status. Histological analysis of radiation-induced damages in visceral organs (liver, kidney, and ileum), performed 64 and 104 d after high-dose body irradiation, indicates that the extent and the evolution of damage depend on both the irradiation dose and organ. A dose-related aggravation of lesions was observed in the liver and kidney but not in the ileum. In contrast to the liver, alterations in the kidney and ileum aggravate with time, emphasizing the need to develop new efficient countermeasures to protect both the gastrointestinal tract and kidney from late-occurring radiation effects. Specifically, the complex evolution of organ damage presented in this paper offers the possibility to explore and then validate specific therapeutic windows using candidate drugs targeted to each injured visceral organ.
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Médula Ósea/efectos de la radiación , Dosis de Radiación , Protección Radiológica , Animales , Antibacterianos/farmacología , Peso Corporal/efectos de la radiación , Relación Dosis-Respuesta en la Radiación , Íleon/patología , Íleon/efectos de la radiación , Riñón/patología , Riñón/efectos de la radiación , Hígado/patología , Hígado/efectos de la radiación , Recuento de Linfocitos , Masculino , Ratas , Ratas WistarRESUMEN
In case of high-dose radiation exposure, mechanisms controlling late visceral organ damage are still not completely understood and may involve the central nervous system. To investigate the influence of cranial/brain irradiation on late visceral organ damage in case of high-dose exposure, Wistar rats were irradiated at 12 Gy, with either the head and fore limbs or the two hind limbs protected behind a lead wall (head- and hind limbs-protected respectively), which allows long-term survival thanks to bone marrow protection. Although hind limbs- and head-protected irradiated rats exhibited similar hematopoietic and spleen reconstitution, a late body weight loss was observed in hind limbs-protected rats only. Histological analysis performed at this time revealed that late damages to liver, kidney and ileum were attenuated in rats with head exposed when compared to animals whose head was protected. Plasma measurements of inflammation biomarkers (haptoglobin and the chemokine CXCL1) suggest that the attenuated organ damage in hind limbs-protected rats may be in part related to reduced acute and chronic inflammation. Altogether our results demonstrate the influence of cranial/brain exposure in the onset of organ damage.
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Encéfalo/efectos de la radiación , Irradiación de Hemicuerpo/efectos adversos , Exposición a la Radiación , Cráneo/efectos de la radiación , Vísceras/patología , Vísceras/efectos de la radiación , Análisis de Varianza , Animales , Quimiocina CXCL1/sangre , Haptoglobinas/metabolismo , Técnicas Histológicas , Ratas , Ratas Wistar , Pérdida de Peso/efectos de la radiaciónRESUMEN
This biodosimetry study used irradiated baboons to investigate the efficacy of a kinetic multiparameter (clinical, physical, and biological) approach for discriminating partial-body irradiation (PBI) and total-body irradiation (TBI). Animals were unilaterally (front) exposed to 60Co gamma rays (8 to 32 cGy min) using either TBI or vertical left hemi-body irradiation (HBI), as follows: 2.5 Gy TBI (n = 2), 5 Gy TBI (n = 2), 5 Gy HBI (n = 2), and 10 Gy HBI (n = 2). Midline tissue doses were measured at the anterior iliac crest level with an ionization chamber, and body dosimetry was performed using thermoluminescent dosimeters. Blood samples were collected before exposure and from 1 h until 200 d after irradiation. Clinical status, complete blood cell count, biochemical parameters, and cytogenetic analysis were evaluated. The partial least square discriminant analysis chosen for statistical analysis showed that the four groups of irradiated baboons were clearly separated. However, the dicentric chromosome assay may not distinguish HBI from TBI in confounding situations where equivalent whole-body doses are similar and the time of exposure is sufficient for peripheral blood lymphocyte homogenization. Interestingly, as bone marrow shielding in HBI animals prevented aplasia from happening, hematologic parameters such as the platelet count and Flt-3 ligand level helped to distinguish HBI and TBI. Moreover, the ratio of neutrophil to lymphocyte counts, creatine kinase, and citrulline levels may be discriminating biomarkers of dose or injury. Both early and delayed clinical signs and bioindicators appear to be useful for assessment of heterogeneous irradiation.
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Modelos Animales , Fenómenos Físicos , Radiometría/métodos , Irradiación Corporal Total , Animales , Células Sanguíneas/efectos de la radiación , Exposición a Riesgos Ambientales/efectos adversos , Rayos gamma , Cinética , Masculino , Papio , Dosis de Radiación , Traumatismos Experimentales por Radiación/sangre , Traumatismos Experimentales por Radiación/metabolismo , Factores de Tiempo , Irradiación Corporal Total/efectos adversosRESUMEN
Although zinc is an essential trace element involved in many physiological functions, toxicological data concerning acute exposure are scarce. The aim of our study was to determine the maximal iterative dose of zinc that can be administrated in rats without any adverse effect. Saline (control group) or zinc gluconate at 1, 2 or 4 mg/kg were intraperitoneally injected in animals daily during 7 days. The tolerance of zinc treatments was evaluated by the observation of clinical symptoms, haematological parameters and biochemistry, in relation to the zinc and copper levels in blood, liver, pancreas and faeces. We found no serious adverse effect within 1 week in rats injected intraperitoneally with 1 or 2 mg/kg/day of zinc gluconate, which tends to indicate that those doses could be useful in future therapeutic research. In contrast, the therapeutic treatment of adult rats with repeated intraperitoneal injections of a 4 mg/kg/day zinc dose should be cancelled, due to the occurrence of clinical adverse effects within a few days, as intraperitoneal local intolerance or major growth underdevelopment.
Asunto(s)
Gluconatos/farmacocinética , Gluconatos/toxicidad , Animales , Peso Corporal/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Heces/química , Gluconatos/administración & dosificación , Inyecciones Intraperitoneales , Hígado/efectos de los fármacos , Hígado/metabolismo , Masculino , Páncreas/efectos de los fármacos , Páncreas/metabolismo , Ratas , Ratas Wistar , Distribución TisularRESUMEN
Previous studies have demonstrated the early appearance of inflammatory cytokines in the systemic circulation after thermal injury both in humans and animals. The aim of this study was to evaluate the time course of several cytokines, IL-6, TNF-alpha and IL-1beta in serum, lung, liver and brain of severely burned rats during the first week after thermal injury. Cytokine measurements were performed by enzyme-linked immunosorbent assay (ELISA). The comparison between the sham-burned animals and animals with third-degree burns on 20% or 40% of their total body surface area allowed for the study of the inflammatory process relative to the size of the injury. Serum IL-6 levels, which were undetectable in sham-treated animals, peaked during the first hours after injury and were proportionate to the size of the area burned. After a few days, IL-6 increased once more, but only in the most severely burned rats. In lung, liver and brain, low but measurable basal levels of TNF-alpha and IL-1 were detected in sham-burned animals. Strikingly, IL-1beta levels remained significantly elevated in the lung after injury in animals having 20% and 40% burned skin area. Unexpectedly, both TNF-alpha and IL-1beta production decreased gradually in liver and brain after burn injury. Also, the inflammatory response after a burn injury appeared to be biphasic. The first period corresponded to the early release of IL-6 into the circulation, proportional to the severity of the injury. After a few days, a second period was marked by the extension of the inflammatory processes from the injured area to the rest of the body, particularly to lung, which could be considered as at potential risk of involvement in severely burned patients.
Asunto(s)
Interleucina-1beta/sangre , Interleucina-1beta/metabolismo , Interleucina-6/sangre , Interleucina-6/metabolismo , Factor de Necrosis Tumoral alfa/sangre , Factor de Necrosis Tumoral alfa/metabolismo , Animales , Quemaduras/sangre , Quemaduras/patología , Citocinas/metabolismo , Calor , Inflamación , Masculino , Modelos Biológicos , Ratas , Ratas Wistar , Proyectos de Investigación , Distribución TisularRESUMEN
The organophosphorus nerve agent soman is an irreversible cholinesterase (ChE) inhibitor that can produce long-lasting seizures and brain damage in which the neurotransmitters acetylcholine and glutamate are involved. These same neurotransmitters play key-roles in the auditory function. It was then assumed that exploring the hearing function may provide markers of the central events triggered by soman intoxication. In the present study, distortion product otoacoustic emissions (DPOAEs), a non-invasive audiometric method, were used to monitor cochlear functionality in rats administered with a moderate dose of soman (45 microg/kg). DPOAEs were investigated either 4h or 24h post-challenge. In parallel, the effects of soman on whole blood and brain ChE activity and on brain histology were also studied. The first main result is that DPOAE intensities were significantly decreased 4h post-soman and returned to baseline at 24h. The amplitude changes were well related to the severity of symptoms, with the greatest change being recorded in the rats that survived long-lasting convulsions. The second main result is that baseline DPOAEs recorded 8 days before soman appear to predict the severity of symptoms produced by the intoxication. Indeed, the lowest baseline DPOAEs corresponded to the occurrence of long-lasting convulsions and brain damage and to the greatest inhibition in central ChE. These results thus suggest that DPOAEs represent a promising non-invasive tool to assess and predict the central consequences of nerve agent poisoning. Further investigations will be carried out to assess the potential applications and the limits of this non-invasive method.