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1.
FASEB J ; 36(2): e22134, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35061296

RESUMO

Astrocytes release gliotransmitters via connexin 43 (Cx43) hemichannels into neighboring synapses, which can modulate synaptic activity and are necessary for fear memory consolidation. However, the gliotransmitters released, and their mechanisms of action remain elusive. Here, we report that fear conditioning training elevated Cx43 hemichannel activity in astrocytes from the basolateral amygdala (BLA). The selective blockade of Cx43 hemichannels by microinfusion of TAT-Cx43L2 peptide into the BLA induced memory deficits 1 and 24 h after training, without affecting learning. The memory impairments were prevented by the co-injection of glutamate and D-serine, but not by the injection of either alone, suggesting a role for NMDA receptors (NMDAR). The incubation with TAT-Cx43L2 decreased NMDAR-mediated currents in BLA slices, effect that was also prevented by the addition of glutamate and D-serine. NMDARs in primary neuronal cultures were unaffected by TAT-Cx43L2, ruling out direct effects of the peptide on NMDARs. Finally, we show that D-serine permeates through purified Cx43 hemichannels reconstituted in liposomes. We propose that the release of glutamate and D-serine from astrocytes through Cx43 hemichannels is necessary for the activation of post-synaptic NMDARs during training, to allow for the formation of short-term and subsequent long-term memory, but not for learning per se.


Assuntos
Astrócitos/metabolismo , Complexo Nuclear Basolateral da Amígdala/metabolismo , Conexina 43/metabolismo , Medo/fisiologia , Memória de Curto Prazo/fisiologia , Neurotransmissores/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Animais , Ácido Glutâmico/metabolismo , Masculino , Neurônios/metabolismo , Ratos , Ratos Sprague-Dawley , Serina/metabolismo
2.
Adv Exp Med Biol ; 1408: 163-181, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37093427

RESUMO

Dexmedetomidine is an adrenergic receptor agonist that has been regarded as neuroprotective in several studies without an objective measure to it. Thus, the aim of this meta-analysis was to analyze and quantify the current evidence for the neuroprotective effects of dexmedetomidine in animals. The search was performed by querying the National Library of Medicine. Studies were included based on their language, significancy of their results, and complete availability of data on animal characteristics and interventions. Risk of bias was assessed using SYRCLE's risk of bias tool and certainty was assessed using the ARRIVE Guidelines 2.0. Synthesis was performed by calculating pooled standardized mean difference and presented in forest plots and tables. The number of eligible records included per outcome is the following: 22 for IL-1ß, 13 for IL-6, 19 for apoptosis, 7 for oxidative stress, 7 for Escape Latency, and 4 for Platform Crossings. At the cellular level, dexmedetomidine was found protective against production of IL-1ß (standardized mean difference (SMD) = - 4.3 [- 4.8; - 3.7]) and IL-6 (SMD = - 5.6 [- 6.7; - 4.6]), apoptosis (measured through TUNEL, SMD = - 6.0 [- 6.8; - 4.6]), and oxidative stress (measured as MDA production, SMD = - 2.0 [- 2.4; - 1.4]) exclusively in the central nervous system. At the organism level, dexmedetomidine improved behavioral outcomes measuring escape latency (SMD = - 2.4 [- 3.3; - 1.6]) and number of platform crossings (SMD = 9.1 [- 6.8; - 11.5]). No eligible study had high risk of bias and certainty was satisfactory for reproducibility in all cases. This meta-analysis highlights the complexity of adrenergic stimulation and sheds light into the mechanisms potentiated by dexmedetomidine, which could be exploited for improving current neuroprotective formulations.


Assuntos
Dexmedetomidina , Fármacos Neuroprotetores , Estados Unidos , Interleucina-6 , Reprodutibilidade dos Testes
3.
Stress ; 25(1): 145-155, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35384793

RESUMO

Worldwide, millions of people suffer from treatment-resistant depression. Ketamine, a glutamatergic receptor antagonist, can have a rapid antidepressant effect even in treatment-resistant patients. A proposed mechanism for the antidepressant effect of ketamine is the reduction of neuroinflammation. To further explore this hypothesis, we investigated whether a single dose of ketamine can modulate protracted neuroinflammation in a repeated social defeat (RSD) stress rat model, which resembles features of depression. To this end, male animals exposed to RSD were injected with ketamine (20 mg/kg) or vehicle. A combination of behavioral analyses and PET scans of the inflammatory marker TSPO in the brain were performed. Rats submitted to RSD showed anhedonia-like behavior in the sucrose preference test, decreased weight gain, and increased TSPO levels in the insular and entorhinal cortices, as observed by [11C]-PK11195 PET. Whole brain TSPO levels correlated with corticosterone levels in several brain regions of RSD exposed animals, but not in controls. Ketamine injection 1 day after RSD disrupted the correlation between TSPO levels and serum corticosterone levels, but had no effect on depressive-like symptoms, weight gain or the protracted RSD-induced increase in TSPO expression in male rats. These results suggest that ketamine does not exert its effect on the hypothalamic-pituitary-adrenal axis by modulation of neuroinflammation.


Assuntos
Anedonia , Ketamina , Doenças Neuroinflamatórias , Animais , Antidepressivos/farmacologia , Proteínas de Transporte , Corticosterona , Depressão/metabolismo , Depressão/prevenção & controle , Modelos Animais de Doenças , Sistema Hipotálamo-Hipofisário/metabolismo , Ketamina/farmacologia , Masculino , Sistema Hipófise-Suprarrenal/metabolismo , Ratos , Receptores de GABA/metabolismo , Receptores de GABA-A , Estresse Psicológico/metabolismo , Aumento de Peso
4.
Int J Mol Sci ; 23(13)2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35806360

RESUMO

Neuropathic pain reduces GABA and glycine receptor (GlyR)-mediated activity in spinal and supraspinal regions associated with pain processing. Interleukin-1ß (IL-1ß) alters Central Amygdala (CeA) excitability by reducing glycinergic inhibition in a mechanism that involves the auxiliary ß-subunit of GlyR (ßGlyR), which is highly expressed in this region. However, GlyR activity and its modulation by IL-1ß in supraspinal brain regions under neuropathic pain have not been studied. We performed chronic constriction injury (CCI) of the sciatic nerve in male Sprague Dawley rats, a procedure that induces hind paw plantar hyperalgesia and neuropathic pain. Ten days later, the rats were euthanized, and their brains were sliced. Glycinergic spontaneous inhibitory currents (sIPSCs) were recorded in the CeA slices. The sIPSCs from CeA neurons of CCI animals show a bimodal amplitude distribution, different from the normal distribution in Sham animals, with small and large amplitudes of similar decay constants. The perfusion of IL-1ß (10 ng/mL) in these slices reduced the amplitudes within the first five minutes, with a pronounced effect on the largest amplitudes. Our data support a possible role for CeA GlyRs in pain processing and in the neuroimmune modulation of pain perception.


Assuntos
Núcleo Central da Amígdala , Neuralgia , Animais , Núcleo Central da Amígdala/metabolismo , Hiperalgesia/metabolismo , Interleucina-1beta/metabolismo , Masculino , Neuralgia/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores de Glicina/metabolismo
5.
Int J Mol Sci ; 23(13)2022 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-35806258

RESUMO

Connexin (Cxs) hemichannels participate in several physiological and pathological processes, but the molecular mechanisms that control their gating remain elusive. We aimed at determining the role of extracellular cysteines (Cys) in the gating and function of Cx46 hemichannels. We studied Cx46 and mutated all of its extracellular Cys to alanine (Ala) (one at a time) and studied the effects of the Cys mutations on Cx46 expression, localization, and hemichannel activity. Wild-type Cx46 and Cys mutants were expressed at comparable levels, with similar cellular localization. However, functional experiments showed that hemichannels formed by the Cys mutants did not open either in response to membrane depolarization or removal of extracellular divalent cations. Molecular-dynamics simulations showed that Cys mutants may show a possible alteration in the electrostatic potential of the hemichannel pore and an altered disposition of important residues that could contribute to the selectivity and voltage dependency in the hemichannels. Replacement of extracellular Cys resulted in "permanently closed hemichannels", which is congruent with the inhibition of the Cx46 hemichannel by lipid peroxides, through the oxidation of extracellular Cys. These results point to the modification of extracellular Cys as potential targets for the treatment of Cx46-hemichannel associated pathologies, such as cataracts and cancer, and may shed light into the gating mechanisms of other Cx hemichannels.


Assuntos
Junções Comunicantes , Ativação do Canal Iônico , Conexinas/metabolismo , Cisteína/metabolismo , Junções Comunicantes/metabolismo
6.
Int J Mol Sci ; 23(21)2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36362410

RESUMO

Gamma-Aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in the brain. It is produced by interneurons and recycled by astrocytes. In neurons, GABA activates the influx of Cl- via the GABAA receptor or efflux or K+ via the GABAB receptor, inducing hyperpolarization and synaptic inhibition. In astrocytes, the activation of both GABAA and GABAB receptors induces an increase in intracellular Ca2+ and the release of glutamate and ATP. Connexin 43 (Cx43) hemichannels are among the main Ca2+-dependent cellular mechanisms for the astroglial release of glutamate and ATP. However, no study has evaluated the effect of GABA on astroglial Cx43 hemichannel activity and Cx43 hemichannel-mediated gliotransmission. Here we assessed the effects of GABA on Cx43 hemichannel activity in DI NCT1 rat astrocytes and hippocampal brain slices. We found that GABA induces a Ca2+-dependent increase in Cx43 hemichannel activity in astrocytes mediated by the GABAA receptor, as it was blunted by the GABAA receptor antagonist bicuculline but unaffected by GABAB receptor antagonist CGP55845. Moreover, GABA induced the Cx43 hemichannel-dependent release of glutamate and ATP, which was also prevented by bicuculline, but unaffected by CGP. Gliotransmission in response to GABA was also unaffected by pannexin 1 channel blockade. These results are discussed in terms of the possible role of astroglial Cx43 hemichannel-mediated glutamate and ATP release in regulating the excitatory/inhibitory balance in the brain and their possible contribution to psychiatric disorders.


Assuntos
Astrócitos , Conexina 43 , Ratos , Animais , Conexina 43/metabolismo , Astrócitos/metabolismo , Receptores de GABA-A , Bicuculina/farmacologia , Animais Recém-Nascidos , Células Cultivadas , Ácido Glutâmico/farmacologia , Ácido gama-Aminobutírico/farmacologia , Trifosfato de Adenosina/farmacologia
7.
Nitric Oxide ; 86: 54-62, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30797972

RESUMO

Under normal conditions, connexin (Cx) hemichannels have a low open probability, which can increase under pathological conditions. Since hemichannels are permeable to relatively large molecules, their exacerbated activity has been linked to cell damage. Cx46 is highly expressed in the lens and its mutations have been associated to cataract formation, but it is unknown whether Cx46 has a role in non-genetic cataract formation (i.e. aging and diabetes). Nitric oxide (NO) is a key element in non-genetic cataract formation and Cx46 hemichannels have been shown to be sensitive to NO. The molecular mechanisms of the effects of NO on Cx46 are unknown, but are likely to result from Cx46 S-nitrosation (also known as S-nitrosylation). In this work, we found that lens opacity was correlated with Cx46 S-nitrosation in an animal model of cataract. Consistent with this result, a NO donor increased Cx46 S-nitrosation and hemichannel opening in HLE-B3 cells (cell line derived from human lens epithelial cells). Mutagenesis studies point to the cysteine located in the fourth transmembrane helix (TM4; human C212, rat C218) as the NO sensor. Electrophysiological studies performed in Xenopus oocytes revealed that rat Cx46 hemichannels are sensitive to different NO donors, and that the presence of C218 is necessary to observe the NO donors' effects. Unexpectedly, gap junctions formed by Cx46 were insensitive to NO or the reducing agent dithiothreitol. We propose that increased hemichannel opening and/or changes in their electrophysiological properties of human Cx46 due to S-nitrosation of the cysteine in TM4 could be an important factor in cataract formation.


Assuntos
Catarata/etiologia , Conexinas/metabolismo , Cisteína/química , Óxido Nítrico/metabolismo , Sequência de Aminoácidos , Animais , Linhagem Celular , Conexinas/química , Cricetulus , Junções Comunicantes/metabolismo , Humanos , Masculino , Potenciais da Membrana/fisiologia , Mesocricetus , Camundongos , Nitrosação , Conformação Proteica em alfa-Hélice , Processamento de Proteína Pós-Traducional , Ratos Sprague-Dawley , Alinhamento de Sequência , Xenopus laevis , Peixe-Zebra
8.
J ECT ; 35(4): e46-e54, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31764455

RESUMO

BACKGROUND: Negative symptoms of schizophrenia show limited response to both typical and atypical antipsychotics. Repetitive transcranial magnetic stimulation applied over the prefrontal cortex (PFC) has been proposed as an adjuvant to pharmacological treatment of negative symptoms in schizophrenia, but whether the improvements obtained are specific to negative symptoms or attributable to antidepressant effects is still unclear. OBJECTIVE: The aim of the present study is to determine to which extent the improvements in negative symptoms of schizophrenia obtained after high-frequency stimulation of the bilateral PFC using deep TMS (dTMS) are attributable to antidepressant effects. METHODS: Repetitive dTMS was administered to the PFC in a cohort of 16 patients with schizophrenia under successful pharmacological control of positive symptoms and predominant negative symptoms. Patients were treated using high-frequency (18 Hz) bilateral stimulation applied over the lateral PFC bilaterally using Brainsway H-2 coil. The effects of dTMS on negative symptoms were measured using the Scale for the Assessment of Negative Symptoms and the Positive and Negative Syndrome Scales. We then compared the improvements in negative symptoms obtained in patients showing depressive symptoms (≥7 points) with those found in patients without depression (>7 points), as determined by the Calgary Scale for Depression. RESULTS: Repetitive dTMS treatment induced significant improvements in negative symptoms as assessed using both Scale for the Assessment of Negative Symptoms and Positive and Negative Syndrome Scales. Comparison of the improvements obtained in patients with or without depression at the beginning of treatment revealed similar improvements in negative symptoms, irrespective of subjacent depression. CONCLUSIONS: Our data suggest that the beneficial effects of high frequency dTMS of the PFC cannot be attributed solely to its antidepressant effects.


Assuntos
Depressão/terapia , Esquizofrenia/terapia , Estimulação Magnética Transcraniana , Adulto , Chile , Feminino , Humanos , Masculino , Córtex Pré-Frontal , Estudos Retrospectivos , Esquizofrenia/tratamento farmacológico
9.
J Cell Biochem ; 119(5): 3922-3935, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29219199

RESUMO

The purinergic receptor P2X3 (P2X3-R) plays important roles in molecular pathways of pain, and reduction of its activity or expression effectively reduces chronic inflammatory and neuropathic pain sensation. Inflammation, nerve injury, and cancer-induced pain can increase P2X3-R mRNA and/or protein levels in dorsal root ganglia (DRG). However, P2X3-R expression is unaltered or even reduced in other pain studies. The reasons for these discrepancies are unknown and might depend on the applied traumatic intervention or on intrinsic factors such as age, gender, genetic background, and/or epigenetics. In this study, we sought to get insights into the molecular mechanisms responsible for inflammatory hyperalgesia by determining P2X3-R expression in DRG neurons of juvenile male rats that received a Complete Freund's Adjuvant (CFA) bilateral paw injection. We demonstrate that all CFA-treated rats showed inflammatory hyperalgesia, however, only a fraction (14-20%) displayed increased P2X3-R mRNA levels, reproducible across both sides. Immunostaining assays did not reveal significant increases in the percentage of P2X3-positive neurons, indicating that increased P2X3-R at DRG somas is not critical for inducing inflammatory hyperalgesia in CFA-treated rats. Chromatin immunoprecipitation (ChIP) assays showed a correlated (R2 = 0.671) enrichment of the transcription factor Runx1 and the epigenetic active mark histone H3 acetylation (H3Ac) at the P2X3-R gene promoter in a fraction of the CFA-treated rats. These results suggest that animal-specific increases in P2X3-R mRNA levels are likely associated with the genetic/epigenetic context of the P2X3-R locus that controls P2X3-R gene transcription by recruiting Runx1 and epigenetic co-regulators that mediate histone acetylation.


Assuntos
Adjuvante de Freund/efeitos adversos , Gânglios Espinais/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Hiperalgesia/induzido quimicamente , Hiperalgesia/metabolismo , Receptores Purinérgicos P2X3/biossíntese , Transcrição Gênica/efeitos dos fármacos , Animais , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Adjuvante de Freund/farmacologia , Gânglios Espinais/patologia , Hiperalgesia/patologia , Masculino , Ratos , Ratos Sprague-Dawley
10.
Brain ; 140(12): 3252-3268, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29155979

RESUMO

The Dlg4 gene encodes for post-synaptic density protein 95 (PSD95), a major synaptic protein that clusters glutamate receptors and is critical for plasticity. PSD95 levels are diminished in ageing and neurodegenerative disorders, including Alzheimer's disease and Huntington's disease. The epigenetic mechanisms that (dys)regulate transcription of Dlg4/PSD95, or other plasticity genes, are largely unknown, limiting the development of targeted epigenome therapy. We analysed the Dlg4/PSD95 epigenetic landscape in hippocampal tissue and designed a Dlg4/PSD95 gene-targeting strategy: a Dlg4/PSD95 zinc finger DNA-binding domain was engineered and fused to effector domains to either repress (G9a, Suvdel76, SKD) or activate (VP64) transcription, generating artificial transcription factors or epigenetic editors (methylating H3K9). These epi-editors altered critical histone marks and subsequently Dlg4/PSD95 expression, which, importantly, impacted several hippocampal neuron plasticity processes. Intriguingly, transduction of the artificial transcription factor PSD95-VP64 rescued memory deficits in aged and Alzheimer's disease mice. Conclusively, this work validates PSD95 as a key player in memory and establishes epigenetic editing as a potential therapy to treat human neurological disorders.


Assuntos
Doença de Alzheimer/genética , Comportamento Animal , Cognição , Proteína 4 Homóloga a Disks-Large/genética , Repressão Epigenética , Hipocampo/metabolismo , Memória , Ativação Transcricional , Doença de Alzheimer/patologia , Doença de Alzheimer/fisiopatologia , Doença de Alzheimer/psicologia , Precursor de Proteína beta-Amiloide/genética , Animais , Modelos Animais de Doenças , Epigênese Genética , Código das Histonas , Humanos , Camundongos , Camundongos Transgênicos , Ratos , Dedos de Zinco
11.
Neurocase ; 23(3-4): 187-192, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28786315

RESUMO

We report reduced repetitive behaviors similar to obsessive compulsive disorder and improved emotional recognition and cognitive abilities in two young patients diagnosed with high-functioning Autism as a result of deep transcranial magnetic stimulation (dTMS). The patients received daily high-frequency (5 Hz) dTMS with HAUT-coil over the medial prefrontal cortex for a period of 5-6 weeks. A computerized cognitive battery, tasks for testing emotional recognition, and clinical questionnaires were used to measure the effects of treatment. TMS might have modulated networks related to metalizing abilities and self-referential processes since both patients reported improved sociability and communication skills.


Assuntos
Síndrome de Asperger/psicologia , Cognição , Transtorno Obsessivo-Compulsivo/complicações , Estimulação Magnética Transcraniana , Adulto , Síndrome de Asperger/complicações , Síndrome de Asperger/terapia , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Córtex Pré-Frontal/fisiopatologia
12.
J ECT ; 32(2): 127-33, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26669743

RESUMO

BACKGROUND: Patients diagnosed with Alzheimer disease (AD) show severe cognitive deficits. Decline in memory, language, and executive function have repeatedly been reported. Although AD affects 60% to 80% of demented elderly patients, there is currently no cure and limited treatment alternatives. OBJECTIVES: The aim of the study was to evaluate the feasibility of stimulating prefrontal cortex (PFC) with deep transcranial magnetic stimulation (dTMS) to ameliorate cognitive deficits in patients suffering from AD. METHODS: Eleven patients (6 males; mean [SD] age, 76 [7] years) in moderate to severe stages of AD received dTMS over the PFC for 20 sessions. Computerized battery (Mindstreams [MS]) and neuropsychological testing (Addenbrooke Cognitive Examination [ACE]) were used to assess cognitive performance before and after treatment. RESULTS: Compared with baseline, 60% of patients performed better on the MS battery and 77% of patients performed better on the ACE testing at the end of dTMS treatment. None of the patients performed worse on both tests at the end of treatment. The DTMS effects on the group mean in ACE and MS approached significance (P = 0.065 and P = 0.086, respectively). A dTMS-induced improvement in the ACE was significant (P = 0.001) on patients in more progressed stage (n = 6). Change in ACE negatively correlated with score at baseline. CONCLUSIONS: In sum, the current report of this novel technique indicates that deep stimulation might lead to preservation and even improvement of cognitive functions, at least during the time of treatment. Further examinations should report of long-term effects of this technique.


Assuntos
Doença de Alzheimer/psicologia , Doença de Alzheimer/terapia , Estimulação Magnética Transcraniana/métodos , Idoso , Idoso de 80 Anos ou mais , Cognição , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/psicologia , Transtornos Cognitivos/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Córtex Pré-Frontal , Resultado do Tratamento
13.
Neurobiol Learn Mem ; 109: 37-45, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24296461

RESUMO

Determining the role of the main gustatory cortical area within the insular cortex (IC), in conditioned taste aversion (CTA) has been elusive due to effective compensatory mechanisms that allow animals to learn in spite of lacking IC. IC lesions performed before CTA training induces mild if any memory impairments, while IC lesions done weeks after CTA produce amnesia. IC lesions before taste presentation have also been shown not to affect taste familiarity learning (attenuation of neophobia). This lack of effect could be either explained by compensation from other brain areas or by a lack of involvement of the IC in taste familiarity. To assess this issue, rats were bilaterally IC lesioned with ibotenic acid (200-300 nl.; 15 mg/ml) one week before or after taste familiarity, using either a preferred (0.1%) or a non-preferred (0.5%) saccharin solution. Rats lesioned before familiarity showed a decrease in neophobia to both solutions but no difference in their familiarity curve or their slope. When animals were familiarized and then IC lesioned, both IC lesioned groups treated the solutions as familiar, showing no differences from sham animals in their retention of familiarity. However, both lesioned groups showed increased latent inhibition (or impaired CTA) when CTA trained after repeated pre-exposures. The role of the IC in familiarity was also assessed using temporary inactivation of the IC, using bilateral micro-infusions of sodium channel blocker bupivacaine before each of 3 saccharin daily presentations. Intra-insular bupivacaine had no effects on familiarity acquisition, but did impair CTA learning in a different group of rats micro-infused before saccharin presentation in a CTA training protocol. Our data indicate that the IC is not essentially involved in acquisition or retention of taste familiarity, suggesting regional dissociation of areas involved in CTA and taste familiarity.


Assuntos
Aprendizagem da Esquiva/fisiologia , Córtex Cerebral/fisiologia , Reconhecimento Psicológico/fisiologia , Percepção Gustatória/fisiologia , Animais , Inibição Psicológica , Masculino , Ratos , Ratos Wistar
14.
J Cell Physiol ; 228(4): 860-70, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23018770

RESUMO

Transient Receptor Potential Vanilloid type 1 channel (TRPV1) is an important endogenous transducer of noxious heat and chemical stimuli and is required during development of inflammatory hypersensitivity. The transcription factor Runx1 is known to play a relevant role in sensory neuron differentiation as it controls the expression of several sensory nociceptive receptors, including TRPV1. Here, we show that Runx1 up-regulates TRPV1 transcription activity by interacting directly with the proximal TRPV1 gene promoter sequence. Importantly, C/EBPß a well-established heterodimer partner of Runx1 also binds to the TRPV1 promoter and cooperates with Runx1 to further stimulate TRPV1 transcription. Our results support a mechanism where Runx1-C/EBPß-containing transcription regulatory complexes are recruited to the TRPV1 gene promoter to modulate TRPV1 expression in dorsal root ganglia neurons.


Assuntos
Proteína beta Intensificadora de Ligação a CCAAT/genética , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Dor/genética , Canais de Cátion TRPV/genética , Animais , Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Gânglios Espinais/metabolismo , Neurônios/metabolismo , Células PC12 , Dor/metabolismo , Regiões Promotoras Genéticas , Ratos , Canais de Cátion TRPV/biossíntese , Canais de Cátion TRPV/metabolismo , Transcrição Gênica , Ativação Transcricional , Regulação para Cima
15.
FASEB J ; 26(9): 3649-57, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22665389

RESUMO

Recent in vitro evidence indicates that astrocytes can modulate synaptic plasticity by releasing neuroactive substances (gliotransmitters). However, whether gliotransmitter release from astrocytes is necessary for higher brain function in vivo, particularly for memory, as well as the contribution of connexin (Cx) hemichannels to gliotransmitter release, remain elusive. Here, we microinfused into the rat basolateral amygdala (BLA) TAT-Cx43L2, a peptide that selectively inhibits Cx43-hemichannel opening while maintaining synaptic transmission or interastrocyte gap junctional communication. In vivo blockade of Cx43 hemichannels during memory consolidation induced amnesia for auditory fear conditioning, as assessed 24 h after training, without affecting short-term memory, locomotion, or shock reactivity. The amnesic effect was transitory, specific for memory consolidation, and was confirmed after microinfusion of Gap27, another Cx43-hemichannel blocker. Learning capacity was recovered after coinfusion of TAT-Cx43L2 and a mixture of putative gliotransmitters (glutamate, glutamine, lactate, d-serine, glycine, and ATP). We propose that gliotransmitter release from astrocytes through Cx43 hemichannels is necessary for fear memory consolidation at the BLA. Thus, the present study is the first to demonstrate a physiological role for astroglial Cx43 hemichannels in brain function, making these channels a novel pharmacological target for the treatment of psychiatric disorders, including post-traumatic stress disorder.


Assuntos
Tonsila do Cerebelo/fisiologia , Astrócitos/metabolismo , Conexina 43/metabolismo , Medo , Memória , Neurotransmissores/metabolismo , Animais , Células Cultivadas , Conexina 43/antagonistas & inibidores , Imuno-Histoquímica , Ratos , Ratos Sprague-Dawley
16.
Biomolecules ; 13(3)2023 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-36979346

RESUMO

BACKGROUND: Connexins (Cxs) are proteins that help cells to communicate with the extracellular media and with the cytoplasm of neighboring cells. Despite their importance in several human physiological and pathological conditions, their pharmacology is very poor. In the last decade, some molecules derived from aminoglycosides have been developed as inhibitors of Cxs hemichannels. However, these studies have been performed in E. coli, which is a very simple model. Therefore, our main goal is to test whether these molecules have similar effects in mammalian cells. METHODS: We transfected HeLa cells with the human Cx46tGFP and characterized the effect of a kanamycin-derived molecule (KI04) on Cx46 hemichannel activity by time-lapse recordings, changes in phosphorylation by Western blot, localization by epifluorescence, and possible binding sites by molecular dynamics (MD). RESULTS: We observed that kanamycin and KI04 were the most potent inhibitors of Cx46 hemichannels among several aminoglycosides, presenting an IC50 close to 10 µM. The inhibitory effect was not associated with changes in Cx46 electrophoretic mobility or its intracellular localization. Interestingly, 5 mM DTT did not reverse KI04 inhibition, but the KI04 effect completely disappeared after washing out KI04 from the recording media. MD analysis revealed two putative binding sites of KI04 in the Cx46 hemichannel. RESULTS: These results demonstrate that KI04 could be used as a Cx46 inhibitor and could help to develop future selective Cx46 inhibitors.


Assuntos
Aminoglicosídeos , Escherichia coli , Animais , Humanos , Células HeLa , Escherichia coli/metabolismo , Conexinas/metabolismo , Antibacterianos , Canamicina/farmacologia , Mamíferos/metabolismo
17.
Psychiatry Res ; 320: 115036, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36586377

RESUMO

Activation of the insula is found in all anxiety-related disorders and increased insular-prefrontal cortex (PFC) functional connectivity is associated with reduced anxiety. In this study, the combined stimulation of the insula and PFC using the dTMS H4 (insula+LPFC) and H2 (PFC) coils were used to reduce anxiety in 13 subjects experiencing occupational stress, and 55 participants suffering from generalized anxiety disorder (GAD). The combined HF stimulation of the insula and PFC significantly decreased anxiety scores according to the HARS, CAS, and STAI anxiety scales, leading to a reduction in anxiety according to HARS of 88.7% and 70.7% in participants with occupational stress and the clinical sample of participants diagnosed with GAD, respectively. The findings suggest that the prefrontal-insular axis is critical for the regulation of anxiety and its stimulation can be used for the treatment of anxiety in people suffering from occupational stress and GAD.


Assuntos
Imageamento por Ressonância Magnética , Estresse Ocupacional , Humanos , Transtornos de Ansiedade/terapia , Córtex Pré-Frontal/diagnóstico por imagem , Ansiedade/terapia
18.
Neuropharmacology ; 237: 109620, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-37263575

RESUMO

Increased activity in the insula has been consistently reported to be associated with anxiety and anxiety-related disorders. However, little is known on how the insula regulates anxiety. The present study aims at determining the role of the insula on the effects of glucocorticoids in anxiety. A combination of pharmacological manipulations, including blockade of adrenal GC synthesis by metyrapone and intra-insular microinjections of corticosterone, corticosterone-BSA, mineralocorticoid receptor (MR) antagonist spironolactone and glucocorticoid receptor (GR) antagonist mifepristone, were used to assess the short-term (5 min) effects of intra-insular corticosterone in two anxiety-like behaviors in male Sprague-Dawley rats. The elevated plus maze (EPM) and Novelty Suppressed Feeding (hyponeophagia) were utilized. We found that corticosterone in the insula is sufficient to prevent the anxiolytic effects corticosterone synthesis blockade in anxiety, and that intra-insular corticosterone has anxiolytic or anxiogenic effects depending on the amount of corticosterone microinjected and the arousal associated to the test, without affecting the HPA axis. Glucocorticoid anxiolytic effects in the insula are mediated by MRs, while its anxiogenic effects are dependent on a mifepristone-sensitive membrane-bound mechanism. Anxiety appears to be modulated at the insula through a competition between fast MR-dependent anxiolytic and membrane-associated anxiogenic signaling pathways that orchestrate the behavioral response to stress and determines the resulting level of anxiety.


Assuntos
Ansiolíticos , Glucocorticoides , Ratos , Animais , Masculino , Glucocorticoides/farmacologia , Glucocorticoides/metabolismo , Corticosterona/metabolismo , Ansiolíticos/farmacologia , Mifepristona/farmacologia , Sistema Hipotálamo-Hipofisário/metabolismo , Ratos Sprague-Dawley , Receptores de Glucocorticoides/metabolismo , Sistema Hipófise-Suprarrenal/metabolismo , Ansiedade/tratamento farmacológico , Ansiedade/metabolismo , Antagonistas de Receptores de Mineralocorticoides/farmacologia , Receptores de Mineralocorticoides/metabolismo
19.
Antioxidants (Basel) ; 12(3)2023 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-36978791

RESUMO

Sepsis syndrome is a highly lethal uncontrolled response to an infection, which is characterized by sepsis-induced coagulopathy (SIC). High-density lipoprotein (HDL) exhibits antithrombotic activity, regulating coagulation in vascular endothelial cells. Sepsis induces the release of several proinflammatory molecules, including reactive oxygen species, which lead to an increase in oxidative stress in blood vessels. Thus, circulating lipoproteins, such as HDL, are oxidized to oxHDL, which promotes hemostatic dysfunction, acquiring prothrombotic properties linked to the severity of organ failure in septic-shock patients (SSP). However, a rigorous and comprehensive investigation demonstrating that oxHDL is associated with a coagulopathy-associated deleterious outcome of SSP, has not been reported. Thus, we investigated the participation of plasma oxHDL in coagulopathy-associated sepsis pathogenesis and elucidated the underlying molecular mechanism. A prospective study was conducted on 42 patients admitted to intensive care units, (26 SSP and 16 non-SSP) and 39 healthy volunteers. We found that an increased plasma oxHDL level in SSP was associated with a prothrombotic phenotype, increased mortality and elevated risk of death, which predicts mortality in SSP. The underlying mechanism indicates that oxHDL triggers an endothelial protein expression reprogramming of coagulation factors and procoagulant adhesion proteins, to produce a prothrombotic environment, mainly mediated by the endothelial LOX-1 receptor. Our study demonstrates that an increased plasma oxHDL level is associated with coagulopathy in SSP through a mechanism involving the endothelial LOX-1 receptor and endothelial protein expression regulation. Therefore, the plasma oxHDL level plays a role in the molecular mechanism associated with increased mortality in SSP.

20.
Psychiatry Res ; 324: 115179, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37030054

RESUMO

Phase IV study evaluated Deep TMS for major depression in community settings. Data were aggregated from 1753 patients at 21 sites, who received Deep TMS (high frequency or iTBS) using the H1 coil. Outcome measures varied across subjects and included clinician-based scales (HDRS-21) and self-assessment questionnaires (PHQ-9, BDI-II). 1351 patients were included in the analysis, 202 received iTBS. For participants with data from at least 1 scale, 30 sessions of Deep TMS led to 81.6% response and 65.3% remission rate. 20 sessions led to 73.6% response and 58.1% remission rate. iTBS led to 72.4% response and 69.2% remission. Remission rates were highest when assessed with HDRS (72%). In 84% of responders and 80% of remitters, response and remission was sustained in the subsequent assessment. Median number of sessions (days) for onset of sustained response was 16 (21 days) and for sustained remission 17 (23 days). Higher stimulation intensity was associated with superior clinical outcomes. This study shows that beyond its proven efficacy in RCTs, Deep TMS with the H1 coil is effective for treating depression under naturalistic conditions, and the onset of improvement is usually within 20 sessions. However, initial non-responders and non-remitters benefit from extended treatment.


Assuntos
Depressão , Transtorno Depressivo Maior , Humanos , Depressão/terapia , Resultado do Tratamento , Estimulação Magnética Transcraniana/métodos , Transtorno Depressivo Maior/terapia , Córtex Pré-Frontal
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