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1.
Luminescence ; 35(8): 1217-1222, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32515166

RESUMO

The relative energy responses of three indigenously developed optically stimulated luminescence (OSL) phosphors in the disc form were studied in therapeutic photon and electron beams. Calibration in terms of absorbed dose was carried out in the dose range 5-500 cGy in 60 Co gamma rays, high energy X-rays, and electron beams used in radiotherapy. The combined standard uncertainty in the estimation of absorbed dose using these OSL discs (OSLDs) was 3.3%. Dose-response curves of these OSLDs in 60 Co gamma rays, 6 and 10 MV (flat and unflat), 15 MV and 6 and 15 MeV electron beams were found to be linear. Furthermore, these OSLDs exhibited a relative energy-dependent response for both photon and electron beams. The relative energy response correction factor for photon and electron beams were in the range 1.01-1.05 and 1.03-1.06, respectively.


Assuntos
Dosimetria por Luminescência Estimulada Opticamente , Dosímetros de Radiação , Elétrons , Luminescência , Fótons , Radiometria
2.
J Am Chem Soc ; 141(44): 17507-17511, 2019 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-31644274

RESUMO

Analytical tools for quantitative measurements of glutamate, the principal excitatory neurotransmitter in the brain, are lacking. Here, we introduce a new enzyme-based amperometric sensor technique for the counting of glutamate molecules stored inside single synaptic vesicles. In this method, an ultra-fast enzyme-based glutamate sensor is placed into a solution of isolated synaptic vesicles, which stochastically rupture at the sensor surface in a potential-dependent manner at a constant negative potential. The continuous amperometric signals are sampled at high speed (10 kHz) to record sub-millisecond spikes, which represent glutamate release from single vesicles that burst open. Glutamate quantification is achieved by a calibration curve that is based on measurements of glutamate release from vesicles pre-filled with various glutamate concentrations. Our measurements show that an isolated single synaptic vesicle encapsulates about 8000 glutamate molecules and is comparable to the measured exocytotic quantal glutamate release in amperometric glutamate sensing in the nucleus accumbens of mouse brain tissue. Hence, this new methodology introduces the means to quantify ultra-small amounts of glutamate and to study synaptic vesicle physiology, pathogenesis, and drug treatments for neuronal disorders where glutamate is involved.


Assuntos
Aminoácido Oxirredutases/química , Técnicas Eletroquímicas/métodos , Ácido Glutâmico/análise , Neurotransmissores/análise , Vesículas Sinápticas/química , Animais , Química Encefálica , Carbono/química , Técnicas Eletroquímicas/instrumentação , Eletrodos , Ácido Glutâmico/química , Ouro/química , Masculino , Nanopartículas Metálicas/química , Camundongos Endogâmicos C57BL , Neurotransmissores/química , Ratos Sprague-Dawley , Lipossomas Unilamelares/química
3.
Neuroendocrinology ; 109(4): 310-321, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30889580

RESUMO

Interleukin (IL)-6 in the hypothalamus and hindbrain is an important downstream mediator of suppression of body weight and food intake by glucagon-like peptide-1 (GLP-1) receptor stimulation. CNS GLP-1 is produced almost exclusively in prepro-glucagon neurons in the nucleus of the solitary tract. These neurons innervate energy balance-regulating areas, such as the external lateral parabrachial nucleus (PBNel); essential for induction of anorexia. Using a validated novel IL-6-reporter mouse strain, we investigated the interactions in PBNel between GLP-1, IL-6, and calcitonin gene-related peptide (CGRP, a well-known mediator of anorexia). We show that PBNel GLP-1R-containing cells highly (to about 80%) overlap with IL-6-containing cells on both protein and mRNA level. Intraperitoneal administration of a GLP-1 analogue exendin-4 to mice increased the proportion of IL-6-containing cells in PBNel 3-fold, while there was no effect in the rest of the lateral parabrachial nucleus. In contrast, injections of an anorexigenic peptide growth and differentiation factor 15 (GDF15) markedly increased the proportion of CGRP-containing cells, while IL-6-containing cells were not affected. In summary, GLP-1R are found on IL-6-producing cells in PBNel, and GLP-1R stimulation leads to an increase in the proportion of cells with IL-6-reporter fluorescence, supporting IL-6 mediation of GLP-1 effects on energy balance.


Assuntos
Proteínas de Transporte/metabolismo , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Interleucina-6/biossíntese , Núcleos Parabraquiais/citologia , Núcleos Parabraquiais/metabolismo , Animais , Regulação do Apetite , Peptídeo Relacionado com Gene de Calcitonina/biossíntese , Proteínas de Transporte/agonistas , Metabolismo Energético/efeitos dos fármacos , Exenatida/administração & dosagem , Exenatida/farmacologia , Genes Reporter/efeitos dos fármacos , Imuno-Histoquímica , Injeções Intraperitoneais , Peptídeos e Proteínas de Sinalização Intracelular , Camundongos , Núcleos Parabraquiais/efeitos dos fármacos
4.
Luminescence ; 34(4): 444-449, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31025441

RESUMO

Dental orthopantogram (OPG)/cone beam computed tomography (CBCT) scanners are gaining popularity due to their 3D imaging with multiplanar view that provides clinical benefits over conventional dental radiography systems. Dental OPG/CBCT provides optimal visualization of adjacent overlaying anatomical structures that will be superpositioned in any single projection. The characteristics of indigenously developed optically stimulated luminescence dosimeters, namely, aluminium oxide doped with carbon (Al2 O3 :C), lithium magnesium phosphate doped with terbium and boron (LiMgPO4 :Tb,B) and lithium calcium aluminium fluoride doped with europium and yttrium (LiCaAlF6 :Eu,Y) were evaluated for their use in dental dosimetry. The dose-response of these dosimeters was studied at X-ray energies 60 kV, 70 kV and 81 kV. Radiation doses were also measured using Gafchromic film for comparison. Radiation dose was measured at eight different locations of a polymethyl methacrylate (PMMA) head phantom including eyes. The optically stimulated luminescence (OSL) sensitivity of LiMgPO4 :Tb,B is about 1.5 times and LiCaAlF6 :Eu, is about 20 times higher than the sensitivity of Al2 O3 :C. It was found that measured radiation doses by the three optically stimulated luminescence dosimeters (OSLDs) and Gafchromic film in the occipital region (back side) of a PMMA phantom, were consistent but variations in dose at other locations were significantly higher. The three OSLDs used in this study were found to be suitable for radiation dose measurement in dental units.


Assuntos
Tomografia Computadorizada de Feixe Cônico , Equipamentos Odontológicos , Dosimetria por Luminescência Estimulada Opticamente , Dosímetros de Radiação , Tomografia Computadorizada de Feixe Cônico/instrumentação , Humanos , Dosimetria por Luminescência Estimulada Opticamente/instrumentação , Óptica e Fotônica , Doses de Radiação
5.
Front Endocrinol (Lausanne) ; 15: 1389589, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38887265

RESUMO

Food intake behavior is under the tight control of the central nervous system. Most studies to date focus on the contribution of neurons to this behavior. However, although previously overlooked, astrocytes have recently been implicated to play a key role in feeding control. Most of the recent literature has focused on astrocytic contribution in the hypothalamus or the dorsal vagal complex. The contribution of astrocytes located in the lateral parabrachial nucleus (lPBN) to feeding behavior control remains poorly understood. Thus, here, we first investigated whether activation of lPBN astrocytes affects feeding behavior in male and female rats using chemogenetic activation. Astrocytic activation in the lPBN led to profound anorexia in both sexes, under both ad-libitum feeding schedule and after a fasting challenge. Astrocytes have a key contribution to glutamate homeostasis and can themselves release glutamate. Moreover, lPBN glutamate signaling is a key contributor to potent anorexia, which can be induced by lPBN activation. Thus, here, we determined whether glutamate signaling is necessary for lPBN astrocyte activation-induced anorexia, and found that pharmacological N-methyl D-aspartate (NMDA) receptor blockade attenuated the food intake reduction resulting from lPBN astrocyte activation. Since astrocytes have been shown to contribute to feeding control by modulating the feeding effect of peripheral feeding signals, we further investigated whether lPBN astrocyte activation is capable of modulating the anorexic effect of the gut/brain hormone, glucagon like peptide -1, as well as the orexigenic effect of the stomach hormone - ghrelin, and found that the feeding effect of both signals is modulated by lPBN astrocytic activation. Lastly, we found that lPBN astrocyte activation-induced anorexia is affected by a diet-induced obesity challenge, in a sex-divergent manner. Collectively, current findings uncover a novel role for lPBN astrocytes in feeding behavior control.


Assuntos
Astrócitos , Ingestão de Alimentos , Núcleos Parabraquiais , Animais , Astrócitos/metabolismo , Astrócitos/fisiologia , Masculino , Feminino , Ratos , Ingestão de Alimentos/fisiologia , Núcleos Parabraquiais/fisiologia , Anorexia/metabolismo , Comportamento Alimentar/fisiologia , Ratos Sprague-Dawley , Ácido Glutâmico/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo
6.
Addict Biol ; 18(4): 605-13, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21790906

RESUMO

Age-related differences in various acute physiological and behavioral effects of alcohol have been demonstrated in humans and in other species. Adolescents are more sensitive to positive reinforcing properties of alcohol than adults, but the cellular mechanisms that underlie such a difference are not clearly established. We, therefore, assessed age differences in the ability of ethanol to modulate glutamatergic synaptic transmission in the mouse nucleus accumbens (NAc), a brain region importantly involved in reward mechanisms. We measured field excitatory postsynaptic potentials/population spikes (fEPSP/PS) in NAc slices from adolescent (22-30 days old) and adult (5-8 months old) male mice. We found that 50mM ethanol applied in the perfusion solution inhibits glutamatergic neurotransmission in the NAc of adolescent, but not adult, mice. This effect is blocked by the gamma-aminobutyric acid (GABA)A receptor antagonist bicuculline and by the GABAB receptor antagonist CGP 55845. Furthermore, bicuculline applied alone produces a stronger increase in the fEPSP/PS amplitude in adult mice than in adolescent mice. Activation of GABAA receptors with muscimol produces a stronger and longer lasting depression of neurotransmission in adolescent mice as compared with adult mice. Activation of GABAB receptors with SKF 97541 also depresses neurotransmission more strongly in adolescent than in adult mice. These results demonstrate that an increased GABA receptor function associated with a reduced inhibitory tone underlies the depressant action of ethanol on glutamatergic neurotransmission in the NAc of adolescent mice.


Assuntos
Depressores do Sistema Nervoso Central/farmacologia , Etanol/farmacologia , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Núcleo Accumbens/efeitos dos fármacos , Receptores de GABA/efeitos dos fármacos , Transmissão Sináptica/efeitos dos fármacos , Adolescente , Adulto , Fatores Etários , Animais , Bicuculina/farmacologia , Relação Dose-Resposta a Droga , Antagonistas GABAérgicos/farmacologia , Agonistas de Receptores de GABA-A/farmacologia , Humanos , Masculino , Camundongos , Muscimol/farmacologia , Ácidos Fosfínicos/farmacologia , Propanolaminas/farmacologia , Recompensa
7.
J Cancer Res Ther ; 19(Supplement): S0, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37147959

RESUMO

Aim: The aim of this study was to carried out the audit of radiotherapy centers practicing conformal radiotherapy techniques and demonstrate the suitability of this indigenous optically stimulated luminescence (OSL) disc dosimeters in beam quality audit and verification of patient-specific dosimetry in conventional and conformal treatments in radiotherapy. Materials and Methods: Dose audit in conventional and conformal (intensity-modulated radiotherapy and volumetric-modulated arc therapy) radiotherapy techniques was conducted using in-house developed Al2O3:C-based OSL disc dosimeter and commercially available Gafchromic EBT3 film in 6 MV (flat and unflat) photon and 6 and 15 MeV electron beams. OSL disc dosimeter and Gafchromic EBT3 film measured dose values were verified using the ionization chamber measurements. Results: Percentage variations of doses measured by OSL disc dosimeters and EBT3 Gafchromic film for conventional radiotherapy technique were in the range of 0.15%-4.6% and 0.40%-5.45%, respectively, with respect to the treatment planning system calculated dose values. For conformal radiotherapy techniques, the percentage variations of OSL disc and EBT3 film measured doses were in the range of 0.1%-4.9% and 0.3%-5.0%, respectively. Conclusion: The results of this study supported by statistical evidence provided the confidence that indigenously developed Al2O3:C-based OSL disc dosimeters are suitable for dose audit in conventional and advanced radiotherapy techniques.


Assuntos
Dosimetria por Luminescência Estimulada Opticamente , Dosímetros de Radiação , Humanos , Luminescência , Radiometria , Óxido de Alumínio
8.
Alcohol Clin Exp Res ; 36(12): 2117-25, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22551245

RESUMO

BACKGROUND: Long-term changes in the efficacy of glutamatergic synaptic transmission in reward-related brain regions such as the nucleus accumbens (NAc) are proposed to contribute to neuroadaptations that lead to drug addiction. Although alcohol is a widely used addictive substance, the cellular mechanisms by which it influences synaptic plasticity in the NAc are not elucidated. We therefore examined whether acute ethanol (EtOH) alters long-term potentiation (LTP) in the core region of the NAc and investigated the possible underlying mechanisms. METHODS: We measured field excitatory postsynaptic potential/population spike (fEPSP/PS) amplitude in mouse brain slices containing the NAc. We also used amperometry to detect, with carbon fiber electrode, evoked dopamine release in brain slices. RESULTS: In control slices, high-frequency stimulation (HFS) induced a stable LTP. LTP was reduced in slices perfused with EtOH (50 mM). Given that induction of LTP is dependent on glutamate acting on N-methyl-d-aspartate (NMDA) receptors and group I metabotropic glutamate receptors (mGluRs), we studied the ability of EtOH to modulate these 2 classes of receptors. NMDA (20 µM) depressed the amplitude of the fEPSP/PS, but this effect was not altered by EtOH in our experimental conditions. However, EtOH reversed the ability of the group I mGluR agonist (S)-3,5-Dihydroxyphenylglycine (DHPG) (50 µM) to potentiate the depressant action of NMDA on the fEPSP/PS. We also examined whether EtOH could modulate dopamine release given that dopamine plays important roles in mediating the reinforcing actions of abused drugs and in the induction of LTP in the NAc. We found that EtOH reversibly decreased action potential-dependent dopamine release evoked by single stimulation pulses and by HFS trains in NAc slices. CONCLUSIONS: These results show that EtOH impairs the induction of LTP possibly through several mechanisms that include inhibition of group I mGluR-mediated potentiation of NMDA receptor function and of evoked dopamine release. This study provides additional support for a key role of glutamatergic and dopaminergic neurotransmission in the NAc in mediating the reinforcing effects of acute alcohol.


Assuntos
Etanol/farmacologia , Núcleo Accumbens/efeitos dos fármacos , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Animais , Dopamina/metabolismo , Antagonistas GABAérgicos/farmacologia , Neurônios GABAérgicos/efeitos dos fármacos , Neurônios GABAérgicos/fisiologia , Potenciação de Longa Duração/efeitos dos fármacos , Potenciação de Longa Duração/fisiologia , Masculino , Metoxi-Hidroxifenilglicol/análogos & derivados , Metoxi-Hidroxifenilglicol/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , N-Metilaspartato/farmacologia , Núcleo Accumbens/fisiologia , Ácidos Fosfínicos/farmacologia , Propanolaminas/farmacologia , Transmissão Sináptica/efeitos dos fármacos , Transmissão Sináptica/fisiologia
9.
3 Biotech ; 12(3): 74, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35251877

RESUMO

A wound-inducible promoter facilitates the regulated gene expression at the targeted site during the time of mechanical stress or infestation by the pathogen. The present work has aimed to identify a wound-inducible promoter that expresses at early time points preceding wound-stress treatment in Arabidopsis thaliana. The computational analysis of microarray data (GSE5627) resulted in the identification of five early inducible genes, viz., AT1G17380, AT1G80440, AT2G43530, AT3G48360, and AT5G13220. The RT-PCR analysis showed AT5G13220 (JASMONATE-ASSOCIATED 1) gene induced at a significantly higher level post 30 min of wounding. Thus, the promoter of the highly induced and early expressed wound-inducible gene, AT5G13220 (named PW220), was characterized by fusing with ß-glucuronidase (gusA) reporter or Cry1EC genes. The fluorometric analysis and histochemical staining of the gusA gene and quantitative estimation of Cry1EC protein in Nicotiana tabacum transgenic lines confirmed wound-induced expression characteristic of the selected promoter. Insect bioassay suggested that wound-inducible and constitutive expression of Cry1EC protein in transgenic lines showed a similar level of protection against different instar Spodoptera litura larvae. Furthermore, we identified that abscisic acid influenced the wound-specific expression of the selected PW220 promoter in the transgenic lines, which correlates with the presence of conserved cis-regulatory elements associated with dehydration and abscisic acid responses. Altogether, our results suggested that the wound-inducible promoter PW220 provides an excellent alternative for developing insect-tolerant transgenic crops in the future. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-022-03143-0.

10.
Mol Metab ; 66: 101614, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36244663

RESUMO

OBJECTIVE: Pancreatic insulin was discovered a century ago, and this discovery led to the first lifesaving treatment for diabetes. While still controversial, nearly one hundred published reports suggest that insulin is also produced in the brain, with most focusing on hypothalamic or cortical insulin-producing cells. However, specific function for insulin produced within the brain remains poorly understood. Here we identify insulin expression in the hindbrain's dorsal vagal complex (DVC), and determine the role of this source of insulin in feeding and metabolism, as well as its response to diet-induced obesity in mice. METHODS: To determine the contribution of Ins2-producing neurons to feeding behavior in mice, we used the cross of transgenic RipHER-cre mouse and channelrhodopsin-2 expressing animals, which allowed us to optogenetically stimulate neurons expressing Ins2 in vivo. To confirm the presence of insulin expression in Rip-labeled DVC cells, in situ hybridization was used. To ascertain the specific role of insulin in effects discovered via optogenetic stimulation a selective, CNS applied, insulin receptor antagonist was used. To understand the physiological contribution of insulin made in the hindbrain a virogenetic knockdown strategy was used. RESULTS: Insulin gene expression and presence of insulin-promoter driven fluorescence in rat insulin promoter (Rip)-transgenic mice were detected in the hypothalamus, but also in the DVC. Insulin mRNA was present in nearly all fluorescently labeled cells in DVC. Diet-induced obesity in mice altered brain insulin gene expression, in a neuroanatomically divergent manner; while in the hypothalamus the expected obesity-induced reduction was found, in the DVC diet-induced obesity resulted in increased expression of the insulin gene. This led us to hypothesize a potentially divergent energy balance role of insulin in these two brain areas. To determine the acute impact of activating insulin-producing neurons in the DVC, optic stimulation of light-sensitive channelrhodopsin 2 in Rip-transgenic mice was utilized. Optogenetic photoactivation induced hyperphagia after acute activation of the DVC insulin neurons. This hyperphagia was blocked by central application of the insulin receptor antagonist S961, suggesting the feeding response was driven by insulin. To determine whether DVC insulin has a necessary contribution to feeding and metabolism, virogenetic insulin gene knockdown (KD) strategy, which allows for site-specific reduction of insulin gene expression in adult mice, was used. While chow-fed mice failed to reveal any changes of feeding or thermogenesis in response to the KD, mice challenged with a high-fat diet consumed less food. No changes in body weight were identified, possibly resulting from compensatory reduction in thermogenesis. CONCLUSIONS: Together, our data suggest an important role for hindbrain insulin and insulin-producing cells in energy homeostasis.


Assuntos
Insulina , Receptor de Insulina , Animais , Camundongos , Ratos , Channelrhodopsins/metabolismo , Comportamento Alimentar , Hiperfagia/metabolismo , Insulina/metabolismo , Camundongos Transgênicos , Obesidade/metabolismo , Receptor de Insulina/metabolismo , Rombencéfalo/metabolismo
11.
Front Behav Neurosci ; 15: 667244, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33927604

RESUMO

Dopaminergic neurons originating from the ventral tegmental area (VTA) and the locus coeruleus are innervating the ventral hippocampus and are thought to play an essential role for efficient cognitive function. Moreover, these VTA projections are hypothesized to be part of a functional loop, in which dopamine regulates memory storage. It is hypothesized that when a novel stimulus is encountered and recognized as novel, increased dopamine activity in the hippocampus induces long-term potentiation and long-term storage of memories. We here demonstrate the importance of increased release of dopamine and norepinephrinein the rat ventral hippocampus on recognition memory, using microdialysis combined to a modified novel object recognition test. We found that presenting rats to a novel object significantly increased dopamine and norepinephrine output in the ventral hippocampus. Two hours after introducing the first object, a second object (either novel or familiar) was placed in the same position as the first object. Presenting the animals to a second novel object significantly increased dopamine and norepinephrine release in the ventral hippocampus, compared to a familiar object. In conclusion, this study suggests that dopamine and norepinephrine output in the ventral hippocampus has a crucial role in recognition memory and signals novelty.

12.
Dermatol Online J ; 16(3): 10, 2010 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-20233567

RESUMO

Peeling Skin Syndrome (PSS) is a rare genodermatoses characterized by asymptomatic, localized or generalized, continuous exfoliation of the stratum corneum; it may present at birth or in adulthood. We describe a patient having the type A non-inflammatory variant of PSS showing asymptomatic and continuous skin peeling from the neck, trunk, back, and extremities. Friction appeared to be an aggravating factor, but there was no seasonal variation. Histopathology in this condition reveals hyperkeratosis and splitting of the epidermis between the granular layer and the stratum corneum. No treatment for this disorder has been found to be effective so far.


Assuntos
Hiperceratose Epidermolítica/patologia , Criança , Feminino , Homozigoto , Humanos , Hiperceratose Epidermolítica/tratamento farmacológico , Hiperceratose Epidermolítica/genética , Hipoproteinemia/patologia , Imunoglobulina E/sangue , Mutação de Sentido Incorreto/genética , Síndrome , Transglutaminases/genética
13.
Radiat Prot Dosimetry ; 189(1): 127-135, 2020 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-32140728

RESUMO

Circular discs of diameter 5 mm were made from three indigenously developed optically stimulated luminescent (OSL) phosphors for medical dosimetry. Dosimetric characteristics of these discs were evaluated for their use in machine and patient-specific dosimetry in radiotherapy. Uncertainty in dosimetric measurements using these discs was also estimated, and combined standard uncertainty in measurement of absorbed dose was found to be 3.34%. Characterisation studies indicate that OSL discs are suitable for dosimetric application in radiotherapy. These discs were also used for patient-specific dosimetry in conventional and conformal radiotherapy treatments (five different cases) vis-à-vis ionisation chamber and Gafchromic EBT3 film. Doses measured by OSL discs were found comparable to ionisation chamber and Gafchromic EBT3 film measured values and radiotherapy treatment planning system (TPS) calculated dose values in all the cases. The variation between TPS calculated dose values and OSL discs measured dose values was found within the measurement uncertainty.


Assuntos
Dosimetria Fotográfica , Radiometria , Humanos , Luminescência
14.
Plant Cell Rep ; 28(12): 1827-36, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19820945

RESUMO

A synthetic DNA construct containing cholera toxin B subunit, genetically fused to the surface glycoprotein of rabies virus was expressed in tobacco plants from a seed specific (legumin) promoter. Seed specific expression was monitored by real-time PCR, GM1-ELISA and Western blot analyses. The fusion protein accumulated in tobacco seeds at up to 1.22% of the total seed protein. It was functionally active in binding to the GM1-ganglioside receptors, suggesting its assembly into pentamers in seeds of the transgenic plants. Immunoblot analysis confirmed that the approximately 80.6 kDa monomeric fusion polypeptide was expressed in tobacco seeds and accumulated as an approximately 403 kDa pentamer. Evaluation of its immunoprotective ability against rabies and cholera is to be examined.


Assuntos
Toxina da Cólera/metabolismo , Glicoproteínas/metabolismo , Nicotiana/genética , Vírus da Raiva/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Sementes/genética , Proteínas Virais/metabolismo , Western Blotting , Clonagem Molecular , DNA de Plantas/genética , Ensaio de Imunoadsorção Enzimática , Regulação da Expressão Gênica de Plantas , Genoma de Planta/genética , Immunoblotting , Plantas Geneticamente Modificadas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transgenes/genética
15.
ACS Chem Neurosci ; 10(3): 1744-1752, 2019 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-30605606

RESUMO

Neuronal communication relies on vesicular neurotransmitter release from signaling neurons and detection of these molecules by neighboring neurons. Glutamate, the main excitatory neurotransmitter in the mammalian brain, is involved in nearly all brain functions. However, glutamate has suffered from detection schemes that lack temporal and spatial resolution allowed by electrochemistry. Here we show an amperometric, novel, ultrafast enzyme-based nanoparticle modified sensor, measuring random bursts of hundreds to thousands of rapid spontaneous glutamate exocytotic release events at approximately 30 Hz frequency in the nucleus accumbens of rodent brain slices. Characterizing these single submillisecond exocytosis events revealed a great diversity in spike shape characteristics and size of quantal release, suggesting variability in fusion pore dynamics controlling the glutamate release by cells in this brain region. Hence, this novel biosensor allows recording of rapid single glutamate exocytosis events in the brain tissue and offers insight on regulatory aspects of exocytotic glutamate release, which is critical to understanding of brain glutamate function and dysfunction.


Assuntos
Exocitose/efeitos dos fármacos , Ácido Glutâmico/farmacologia , Neurônios/efeitos dos fármacos , Neurotransmissores/metabolismo , Animais , Técnicas Biossensoriais/métodos , Encéfalo/efeitos dos fármacos , Eletroquímica/métodos , Exocitose/fisiologia , Camundongos
16.
J Neuroendocrinol ; 31(6): e12722, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31033078

RESUMO

Neuronal circuits involving the central amygdala (CeA) are gaining prominence as important centres for regulation of metabolic functions. As a part of the subcortical food motivation circuitry, CeA is associated with food motivation and hunger. We have previously shown that interleukin (IL)-6 can act as a downstream mediator of the metabolic effects of glucagon-like peptide-1 (GLP-1) receptor (R) stimulation in the brain, although the sites of these effects are largely unknown. In the present study, we used the newly generated and validated RedIL6 reporter mouse strain to investigate the presence of IL-6 in the CeA, as well as possible interactions between IL-6 and GLP-1 in this nucleus. IL-6 was present in the CeA, mostly in cells in the medial and lateral parts of this structure, and a majority of IL-6-containing cells also co-expressed GLP-1R. Triple staining showed GLP-1 containing fibres co-staining with synaptophysin close to or overlapping with IL-6 containing cells. GLP-1R stimulation enhanced IL-6 mRNA levels. IL-6 receptor-alpha (IL-6Rα) was found to a large part in neuronal CeA cells. Using electrophysiology, we determined that cells with neuronal properties in the CeA could be rapidly stimulated by IL-6 administration in vitro. Moreover, microinjections of IL-6 into the CeA could slightly reduce food intake in vivo in overnight fasted rats. In conclusion, IL-6 containing cells in the CeA express GLP-1R, are close to GLP-1-containing synapses, and demonstrate increased IL-6 mRNA in response to GLP-1R agonist treatment. IL-6, in turn, exerts biological effects in the CeA, possibly via IL-6Rα present in this nucleus.


Assuntos
Núcleo Central da Amígdala/metabolismo , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Interleucina-6/metabolismo , Neurônios/metabolismo , Animais , Feminino , Receptor do Peptídeo Semelhante ao Glucagon 1/análise , Interleucina-6/análise , Masculino , Camundongos , RNA Mensageiro/metabolismo , Sinapses/metabolismo
17.
Mol Metab ; 20: 178-193, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30528281

RESUMO

OBJECTIVE: The supramammillary nucleus (SuM) is nestled between the lateral hypothalamus (LH) and the ventral tegmental area (VTA). This neuroanatomical position is consistent with a potential role of this nucleus to regulate ingestive and motivated behavior. Here neuroanatomical, molecular, and behavior approaches are utilized to determine whether SuM contributes to ingestive and food-motivated behavior control. METHODS: Through the application of anterograde and retrograde neural tract tracing with novel designer viral vectors, the current findings show that SuM neurons densely innervate the LH in a sex dimorphic fashion. Glucagon-like peptide-1 (GLP-1) is a clinically targeted neuro-intestinal hormone with a well-established role in regulating energy balance and reward behaviors. Here we determine that GLP-1 receptors (GLP-1R) are expressed throughout the SuM of both sexes, and also directly on SuM LH-projecting neurons and investigate the role of SuM GLP-1R in the regulation of ingestive and motivated behavior in male and female rats. RESULTS: SuM microinjections of the GLP-1 analogue, exendin-4, reduced ad libitum intake of chow, fat, or sugar solution in both male and female rats, while food-motivated behaviors, measured using the sucrose motivated operant conditioning test, was only reduced in male rats. These data contrasted with the results obtained from a neighboring structure well known for its role in motivation and reward, the VTA, where females displayed a more potent response to GLP-1R activation by exendin-4. In order to determine the physiological role of SuM GLP-1R signaling regulation of energy balance, we utilized an adeno-associated viral vector to site-specifically deliver shRNA for the GLP-1R to the SuM. Surprisingly, and in contrast to previous results for the two SuM neighboring sites, LH and VTA, SuM GLP-1R knockdown increased food seeking and adiposity in obese male rats without altering food intake, body weight or food motivation in lean or obese, female or male rats. CONCLUSION: Taken together, these results indicate that SuM potently contributes to ingestive and motivated behavior control; an effect contingent on sex, diet/homeostatic energy balance state and behavior of interest. These data also extend the map of brain sites directly responsive to GLP-1 agonists, and highlight key differences in the role that GLP-1R play in interconnected and neighboring nuclei.


Assuntos
Gânglios da Base/metabolismo , Ingestão de Alimentos , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Hipotálamo/metabolismo , Motivação , Animais , Gânglios da Base/citologia , Gânglios da Base/fisiologia , Condicionamento Operante , Metabolismo Energético , Feminino , Receptor do Peptídeo Semelhante ao Glucagon 1/genética , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Hipotálamo/citologia , Hipotálamo/fisiologia , Masculino , Vias Neurais/citologia , Vias Neurais/metabolismo , Vias Neurais/fisiologia , Ratos , Ratos Sprague-Dawley , Fatores Sexuais
18.
Cell Rep ; 26(11): 3011-3026.e5, 2019 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-30865890

RESUMO

Chronic low-grade inflammation and increased serum levels of the cytokine IL-6 accompany obesity. For brain-produced IL-6, the mechanisms by which it controls energy balance and its role in obesity remain unclear. Here, we show that brain-produced IL-6 is decreased in obese mice and rats in a neuroanatomically and sex-specific manner. Reduced IL-6 mRNA localized to lateral parabrachial nucleus (lPBN) astrocytes, microglia, and neurons, including paraventricular hypothalamus-innervating lPBN neurons. IL-6 microinjection into lPBN reduced food intake and increased brown adipose tissue (BAT) thermogenesis in male lean and obese rats by increasing thyroid and sympathetic outflow to BAT. Parabrachial IL-6 interacted with leptin to reduce feeding. siRNA-mediated reduction of lPBN IL-6 leads to increased weight gain and adiposity, reduced BAT thermogenesis, and increased food intake. Ambient cold exposure partly normalizes the obesity-induced suppression of lPBN IL-6. These results indicate that lPBN-produced IL-6 regulates feeding and metabolism and pinpoints (patho)physiological contexts interacting with lPBN IL-6.


Assuntos
Peso Corporal , Ingestão de Alimentos , Metabolismo Energético , Interleucina-6/metabolismo , Núcleos Parabraquiais/metabolismo , Termogênese , Tecido Adiposo Marrom/metabolismo , Animais , Astrócitos/metabolismo , Feminino , Interleucina-6/genética , Leptina/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Núcleos Parabraquiais/fisiologia , Ratos , Ratos Sprague-Dawley , Sistema Nervoso Simpático/fisiologia , Hormônios Tireóideos/metabolismo
19.
J Genet ; 97(1): 109-119, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29666330

RESUMO

Lack of regulated expression and tissue specificity are the major drawbacks of plant and virus-derived constitutive promoters. A precise tissue or site-specific expression, facilitate regulated expression of proteins at the targeted time and site. Publically available microarray data on whitefly and aphid infested Arabidopsis thaliana L. was used to identify whitefly and aphid-inducible genes. The qRT-PCR further validated the inducible behaviour of these genes under artificial infestation. Promoter sequences of genes were retrieved from the Arabidopsis Information Resources database with their corresponding 5'UTR and cloned from the A. thaliana genome. Promoter reporter transcriptional fusions were developed with the beta-glucuronidase (GUS) gusA gene in a binary expression vector to validate the inducible behaviour of these promoters in eight independent transgenic Nicotiana tabaccum lines. Histochemical analysis of the reporter gene in T2 transgenic tobacco lines confirmed promoter driven expression at the sites of aphid and whitefly infestation. The qRT-PCR and GUS expression analysis of transgenic lines revealed that abscisic acid largely influenced the expression of both aphid and whitefly inducible promoters. Further, whitefly-specific promoter respond to salicylic acid and jasmonic acid (JA), whereas aphid-specific promoters to JA and 1-aminocyclopropane carboxylic acid. The response of promoters to phytohormones correlated to the presence of corresponding conserved cis-regulatory elements.


Assuntos
Afídeos/fisiologia , Arabidopsis/genética , Arabidopsis/parasitologia , Regulação da Expressão Gênica de Plantas , Hemípteros/fisiologia , Regiões Promotoras Genéticas , Ácido Abscísico/farmacologia , Animais , Ciclopentanos/farmacologia , Genes de Plantas , Glucuronidase/metabolismo , Oxilipinas/farmacologia , Doenças das Plantas/genética , Doenças das Plantas/parasitologia , Plantas Geneticamente Modificadas , Reação em Cadeia da Polimerase em Tempo Real , Reprodutibilidade dos Testes , Ácido Salicílico/farmacologia , Nicotiana/genética
20.
Brain Struct Funct ; 222(5): 2031-2039, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27709300

RESUMO

World-wide methamphetamine (meth) use is increasing at a rapid rate; therefore, it has become increasingly important to understand the synaptic changes and neural mechanisms affected by drug exposure. In rodents, 6-h access to contingent meth results in an escalation of drug intake and impaired cognitive sequelae typically associated with changes within the corticostriatal circuitry. There is a dearth of knowledge regarding the underlying physiological changes within this circuit following meth self-administration. We assessed pre- and postsynaptic changes in glutamate transmission in the medial prefrontal cortex (mPFC) and nucleus accumbens (NAc) following daily 6-h meth self-administration. In the mPFC, meth caused postsynaptic adaptations in ionotropic glutamate receptor distribution and function, expressed as a decrease in AMPA/NMDA ratio. This change was driven by an increase in NMDA receptor currents and an increase in GluN2B surface expression. In the NAc, meth decreased the paired-pulse ratio and increased the frequency of spontaneous excitatory postsynaptic currents with no indication of postsynaptic changes. These changes in mPFC synapses and NAc activity begin to characterize the impact of meth on the corticostriatal circuitry.


Assuntos
Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Ácido Glutâmico/metabolismo , Metanfetamina/farmacologia , Sinapses/efeitos dos fármacos , Animais , Estimulantes do Sistema Nervoso Central/farmacologia , Extinção Psicológica/efeitos dos fármacos , Masculino , Metanfetamina/administração & dosagem , Núcleo Accumbens/efeitos dos fármacos , Núcleo Accumbens/metabolismo , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/metabolismo , Ratos Sprague-Dawley , Autoadministração , Sinapses/metabolismo
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