RESUMO
Sugarcane production is strongly influenced by drought, which is a limiting factor for agricultural productivity in the world. In this study, the gene expression profiles obtained by de novo assembly of the leaf transcriptome of two sugarcane cultivars that differ in their physiological response to water deficit were evaluated by the RNA-Seq method: drought-tolerant cultivar (SP81-3250) and drought-sensitive cultivar (RB855453). For this purpose, plants were grown in a greenhouse for 60 days and were then submitted to three treatments: control (-0.01 to -0.015 MPa), moderate water deficit (-0.05 to -0.055 MPa), and severe water deficit (-0.075 to -0.08 MPa). The plants were evaluated 30, 60, and 90 days after the beginning of treatment. Sequencing on an Illumina platform (RNA-Seq) generated more than one billion sequences, resulting in 177,509 and 185,153 transcripts for the tolerant and sensitive cultivar, respectively. These transcripts were aligned with sequences from Saccharum spp, Sorghum bicolor, Miscanthus giganteus, and Arabidopsis thaliana available in public databases. The differentially expressed genes detected during the prolonged period of water deficit permit to increase our understanding of the molecular patterns involved in the physiological response of the two cultivars. The tolerant cultivar differentially expressed a larger number of genes at 90 days, while in the sensitive cultivar the number of differentially expressed genes was higher in 30 days. Both cultivars perceived the lack of water, but the tolerant cultivar responded more slowly than the sensitive cultivar. The latter requires rapid activation of different water-deficit stress response mechanisms for its survival. This rapid activation of metabolic pathways in response to water stress does not appear to be the key mechanism of drought tolerance in sugarcane. There is still much to clarify on the molecular and physiological pattern of plants in response to drought.
Assuntos
Pressão Osmótica , Folhas de Planta/metabolismo , Saccharum/genética , Transcriptoma , Secas , Regulação da Expressão Gênica de Plantas , Folhas de Planta/genética , Saccharum/embriologiaRESUMO
Objetivo: Estudiar la actividad antioxidante y marcha fitoquímica de los capítulos de Tagetes filifolia Lag. "pacha anís".Materiales y métodos: Estudio de tipo experimental en el cual se empleó 5 kg de los capítulos de la planta medicinal Tagetes filifolia lag., provenientes de Junín. Se usó el método de cribado fitoquímico de Olga Lock para la marcha fitoquímica y el método DPPH para la determinación de la actividad antioxidante. Se dividió la muestra en 3 grupos: etéreo, alcohol etílico y agua destilada a concentraciones de 100, 50 y 5 µg/ml.Resultados: Se encontró fenoles en cantidades abundantes tanto en el extracto en agua destilada como en el extracto en alcohol etílico, además este último tuvo cantidades moderadas de quinonas. Por otro lado, el extracto en alcohol etílico fue el que presentó el mayor porcentaje de captación de radicales libres (91.26%) a una concentración de 100 µg/ml, similares resultados se encontró con el extracto etéreo (88.94%) y el extracto en agua destilada (75.58%).Conclusiones: Los principales componentes químicos fueron fenoles y quinonas. El mayor efecto antioxidante se obtuvo del extracto etanólico de la planta Tagetes filifolia a una concentración de 100 µg/ml.
Assuntos
Plantas Medicinais , Tagetes/química , Antioxidantes , Peru , Peneiramento de Líquidos , Compostos FitoquímicosRESUMO
In a previous study we showed that rats chronically treated with corticosterone (CORT) display anxiogenic behavior, evidenced by facilitation of avoidance responses in the elevated T-maze (ETM) model of anxiety. Treatment with the tricyclic antidepressant imipramine significantly reversed the anxiogenic effects of CORT, while inhibiting ETM escape, a response related to panic disorder. To better understand the neurobiological mechanisms underlying these behavioral effects, analysis of c-fos protein immunoreactivity (fos-ir) was used here to map areas activated by chronic CORT (200 mg pellets, 21-day release) and imipramine (15 mg/kg, IP) administration. We also evaluated the number of cells expressing the neurogenesis marker doublecortin (DCX) in the hippocampus and measured plasma CORT levels on the 21st day of treatment. Results showed that CORT increased fos-ir in the ventrolateral septum, medial amygdala and paraventricular hypothalamic nucleus and decreased fos-ir in the lateral periaqueductal gray. Imipramine, on the other hand, increased fos-ir in the medial amygdala and decreased fos-ir in the anterior hypothalamus. CORT also decreased the number of DCX-positive cells in the ventral and dorsal hippocampus, an effect antagonized by imipramine. CORT levels were significantly higher after treatment. These data suggest that the behavioral effects of CORT and imipramine are mediated through specific, at times overlapping, neuronal circuits, which might be of relevance to a better understanding of the physiopathology of generalized anxiety and panic disorder.
Assuntos
Corticosterona/administração & dosagem , Hipocampo/efeitos dos fármacos , Imipramina/administração & dosagem , Neurogênese/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-fos/metabolismo , Tonsila do Cerebelo/efeitos dos fármacos , Tonsila do Cerebelo/metabolismo , Animais , Proteínas do Domínio Duplacortina , Proteína Duplacortina , Hipocampo/metabolismo , Hipotálamo/efeitos dos fármacos , Hipotálamo/metabolismo , Masculino , Proteínas Associadas aos Microtúbulos/metabolismo , Neurogênese/fisiologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neuropeptídeos/metabolismo , Ratos , Ratos WistarRESUMO
It is known that chronic high levels of corticosterone (CORT) enhance aversive responses such as avoidance and contextual freezing. In contrast, chronic CORT does not alter defensive behavior induced by the exposure to a predator odor. Since different defense-related responses have been associated with specific anxiety disorders found in clinical settings, the observation that chronic CORT alters some defensive behaviors but not others might be relevant to the understanding of the neurobiology of anxiety. In the present study, we investigated the effects of chronic CORT administration (through surgical implantation of a 21-day release 200 mg pellet) on avoidance acquisition and escape expression by male Wistar rats (200 g in weight at the beginning of the experiments, N = 6-10/group) tested in the elevated T-maze (ETM). These defensive behaviors have been associated with generalized anxiety and panic disorder, respectively. Since the tricyclic antidepressant imipramine is successfully used to treat both conditions, the effects of combined treatment with chronic imipramine (15 mg, ip) and CORT were also investigated. Results showed that chronic CORT facilitated avoidance performance, an anxiogenic-like effect (P < 0.05), without changing escape responses. Imipramine significantly reversed the anxiogenic effect of CORT (P < 0.05), although the drug did not exhibit anxiolytic effects by itself. Confirming previous observations, imipramine inhibited escape responses, a panicolytic-like effect. Unlike chronic CORT, imipramine also decreased locomotor activity in an open field. These data suggest that chronic CORT specifically altered ETM avoidance, a fact that should be relevant to a better understanding of the physiopathology of generalized anxiety and panic disorder.
Assuntos
Animais , Masculino , Ratos , Antidepressivos Tricíclicos/administração & dosagem , Ansiedade/tratamento farmacológico , Comportamento Animal/efeitos dos fármacos , Corticosterona/administração & dosagem , Imipramina/administração & dosagem , Transtorno de Pânico/tratamento farmacológico , Antidepressivos Tricíclicos/farmacologia , Corticosterona/farmacologia , Reação de Fuga/efeitos dos fármacos , Imipramina/farmacologia , Aprendizagem em Labirinto/efeitos dos fármacos , Atividade Motora/efeitos dos fármacos , Ratos WistarRESUMO
It is known that chronic high levels of corticosterone (CORT) enhance aversive responses such as avoidance and contextual freezing. In contrast, chronic CORT does not alter defensive behavior induced by the exposure to a predator odor. Since different defense-related responses have been associated with specific anxiety disorders found in clinical settings, the observation that chronic CORT alters some defensive behaviors but not others might be relevant to the understanding of the neurobiology of anxiety. In the present study, we investigated the effects of chronic CORT administration (through surgical implantation of a 21-day release 200 mg pellet) on avoidance acquisition and escape expression by male Wistar rats (200 g in weight at the beginning of the experiments, N = 6-10/group) tested in the elevated T-maze (ETM). These defensive behaviors have been associated with generalized anxiety and panic disorder, respectively. Since the tricyclic antidepressant imipramine is successfully used to treat both conditions, the effects of combined treatment with chronic imipramine (15 mg, ip) and CORT were also investigated. Results showed that chronic CORT facilitated avoidance performance, an anxiogenic-like effect (P < 0.05), without changing escape responses. Imipramine significantly reversed the anxiogenic effect of CORT (P < 0.05), although the drug did not exhibit anxiolytic effects by itself. Confirming previous observations, imipramine inhibited escape responses, a panicolytic-like effect. Unlike chronic CORT, imipramine also decreased locomotor activity in an open field. These data suggest that chronic CORT specifically altered ETM avoidance, a fact that should be relevant to a better understanding of the physiopathology of generalized anxiety and panic disorder.
Assuntos
Antidepressivos Tricíclicos/administração & dosagem , Ansiedade/tratamento farmacológico , Comportamento Animal/efeitos dos fármacos , Corticosterona/administração & dosagem , Imipramina/administração & dosagem , Transtorno de Pânico/tratamento farmacológico , Animais , Antidepressivos Tricíclicos/farmacologia , Corticosterona/farmacologia , Reação de Fuga/efeitos dos fármacos , Imipramina/farmacologia , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Atividade Motora/efeitos dos fármacos , Ratos , Ratos WistarRESUMO
Insulin-dependent diabetes mellitus is caused by autoimmune destruction of pancreatic beta cells. Non-obese diabetic (NOD) mice spontaneously develop diabetes similar to the human disease. Cytokines produced by islet-infiltrating mononuclear cells may be directly cytotoxic and can be involved in islet destruction coordinated by CD4+ and CD8+ cells. We utilized a semiquantitative RT-PCR assay to analyze in vitro the mRNA expression of TNF-alpha and IFN-gamma cytokine genes in isolated islets (N = 100) and spleen cells (5 x 10(5) cells) from female NOD mice during the development of diabetes and from female CBA-j mice as a related control strain that does not develop diabetes. Cytokine mRNAs were measured at 2, 4, 8, 14 and 28 weeks of age from the onset of insulitis to the development of overt diabetes. An increase in IFN-gamma expression in islets was observed for females aged 28 weeks (149 +/- 29 arbitrary units (AU), P<0.05, Student t-test) with advanced destructive insulitis when compared with CBA-j mice, while TNF-alpha was expressed in both NOD and CBA-j female islets at the same level at all ages studied. In contrast, TNF-alpha in spleen was expressed at higher levels in NOD females at 14 weeks (99 +/- 8 AU, P<0.05) and 28 weeks (144 +/- 17 AU, P<0.05) of age when compared to CBA-j mice. The data suggest that IFN-gamma and TNF-alpha expression in pancreatic islets of female NOD mice is associated with beta cell destruction and overt diabetes.
Assuntos
Diabetes Mellitus Tipo 1/metabolismo , Interferon gama/metabolismo , Ilhotas Pancreáticas/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Fatores Etários , Animais , Feminino , Expressão Gênica , Interferon gama/genética , Cinética , Camundongos , Camundongos Endogâmicos CBA , Camundongos Endogâmicos NOD , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Baço/citologia , Baço/metabolismo , Fator de Necrose Tumoral alfa/genéticaRESUMO
Insulin-dependent diabetes mellitus is caused by autoimmune destruction of pancreatic ß cells. Non-obese diabetic (NOD) mice spontaneously develop diabetes similar to the human disease. Cytokines produced by islet-infiltrating mononuclear cells may be directly cytotoxic and can be involved in islet destruction coordinated by CD4+ and CD8+ cells. We utilized a semiquantitative RT-PCR assay to analyze in vitro the mRNA expression of TNF-alpha and IFN-gamma cytokine genes in isolated islets (N = 100) and spleen cells (5 x 10(5) cells) from female NOD mice during the development of diabetes and from female CBA-j mice as a related control strain that does not develop diabetes. Cytokine mRNAs were measured at 2, 4, 8, 14 and 28 weeks of age from the onset of insulitis to the development of overt diabetes. An increase in IFN-gamma expression in islets was observed for females aged 28 weeks (149 ± 29 arbitrary units (AU), P<0.05, Student t-test) with advanced destructive insulitis when compared with CBA-j mice, while TNF-alpha was expressed in both NOD and CBA-j female islets at the same level at all ages studied. In contrast, TNF-alpha in spleen was expressed at higher levels in NOD females at 14 weeks (99 ± 8 AU, P<0.05) and 28 weeks (144 ± 17 AU, P<0.05) of age when compared to CBA-j mice. The data suggest that IFN-gamma and TNF-alpha expression in pancreatic islets of female NOD mice is associated with ß cell destruction and overt diabetes
Assuntos
Animais , Feminino , Camundongos , Diabetes Mellitus Tipo 1 , Interferon gama , Ilhotas Pancreáticas , Fator de Necrose Tumoral alfa , Fatores Etários , Expressão Gênica , Interferon gama , Cinética , Camundongos Endogâmicos NOD , Reação em Cadeia da Polimerase Via Transcriptase Reversa , RNA Mensageiro , Baço , Fator de Necrose Tumoral alfaRESUMO
Immunity to mycobacterial antigens may contribute to the maintenance of self-tolerance. Exposure of the immune system to mycobacterial antigen might well stimulate the immune system to exert control over unwanted self-reactive clones. We demonstrated that in vivo administration of Mycobacterium tuberculosis, PPD, and PPD peptide (180-196) prior to immunization with Myelin Basic Protein (MBP) led to a moderate increase of gammadelta T cells, suppression of the immune response, and reduction in the severity of Experimental Autoimmune Encephalomyelitis. The immunosuppression observed is due, at least in part, to the production of Transforming growth factor-beta (TGFbeta) by the gammadelta T lymphocytes.
Assuntos
Antígenos de Bactérias/imunologia , Encefalomielite Autoimune Experimental/imunologia , Mycobacterium/imunologia , Receptores de Antígenos de Linfócitos T gama-delta/imunologia , Linfócitos T/imunologia , Transferência Adotiva , Animais , Modulação Antigênica , Antígenos de Bactérias/farmacologia , Divisão Celular/imunologia , Células Cultivadas , Feminino , Ativação Linfocitária/imunologia , Proteína Básica da Mielina/imunologia , Proteína Básica da Mielina/farmacologia , Ratos , Ratos Endogâmicos Lew , Receptores de Antígenos de Linfócitos T gama-delta/efeitos dos fármacos , Linfócitos T/citologia , Fator de Crescimento Transformador beta/biossíntese , Tuberculina/farmacologiaRESUMO
Outward current oscillations associated with transient membrane hyperpolarizations were induced in murine macrophage polykaryons by membrane depolarization in the absence of external Na+. Oscillations corresponded to a cyclic activation of Ca2+ -dependent K+ currents (IKCa) probably correlated with variations in intracellular Ca2+ concentration. Addition of external Na+ (8mM) immediately abolished the outward current oscillations, suggesting that the absence of the cation is necessary not only for their induction but also for their maintenance. Oscillations were completely blocked by nisoldipine. Ruthenium red and ryanodine reduced the number of outward current cycles in each episode, whereas quercetin prolonged the hyperpolarization 2- to 15-fold. Neither low molecular weight heparin nor the absence of a Na+ gradient across the membrane had any influence on oscillations. The evidence suggests that Ca+ entry through a pathway sensitive to Ca2+ channel blockers is elicited by membrane depolarization in Na+ -free medium and is essential to initiate oscillations, which are also dependent on the cyclic release of Ca2+ from intracellular Ca2+ -sensitive stores; Ca2+ ATPase acts by reducing intracellular Ca2+, thus allowing slow deactivation of IKCa. Evidence is presented that neither a Na+/Ca2+ antiporter nor Ca2+ release from IP3 -sensitive Ca2+ stores participate directly in the mechanism of oscillation.
Assuntos
Animais , Camundongos , Cálcio/fisiologia , Células Gigantes/fisiologia , Macrófagos/fisiologia , Peritônio/fisiologia , Potássio/fisiologia , Bloqueadores dos Canais de Cálcio , ATPases Transportadoras de Cálcio , Transporte de Íons , Potenciais da MembranaRESUMO
Outward current oscillations associated with transient membrane hyperpolarizations were induced in murine macrophage polykaryons by membrane depolarization in the absence of external Na+. Oscillations corresponded to a cyclic activation of Ca(2+)-dependent K+ currents (IKCa) probably correlated with variations in intracellular Ca2+ concentration. Addition of external Na+ (8 mM) immediately abolished the outward current oscillations, suggesting that the absence of the cation is necessary not only for their induction but also for their maintenance. Oscillations were completely blocked by nisoldipine. Ruthenium red and ryanodine reduced the number of outward current cycles in each episode, whereas quercetin prolonged the hyperpolarization 2- to 15-fold. Neither low molecular weight heparin nor the absence of a Na+ gradient across the membrane had any influence on oscillations. The evidence suggests that Ca2+ entry through a pathway sensitive to Ca2+ channel blockers is elicited by membrane depolarization in Na(+)-free medium and is essential to initiate oscillations, which are also dependent on the cyclic release of Ca2+ from intracellular Ca(2+)-sensitive stores; Ca2+ ATPase acts by reducing intracellular Ca2+, thus allowing slow deactivation of IKCa. Evidence is presented that neither a Na+/Ca2+ antiporter nor Ca2+ release from IP3-sensitive Ca2+ stores participate directly in the mechanism of oscillation.