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1.
J Cutan Pathol ; 51(6): 415-418, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38468572

RESUMO

Anetoderma or macular atrophy is a rare skin condition of unclear pathogenesis, often associated with autoimmune diseases and skin damage from various infections. Human immunodeficiency virus (HIV), syphilis, and poxviruses have been implicated in the development of anetoderma. A 37-year-old male patient with HIV and recent unprotected sexual encounters presented with more than 400 skin lesions, consistent with Mpox. Symptomatic treatment for Mpox resulted in acute symptom resolution. However, 8 months later he developed papular anetoderma lesions in areas previously affected by Mpox. Biopsy confirmed the loss of elastic fibers in the affected skin areas, leading to the diagnosis of Mpox-induced anetoderma. This report presents a unique case of anetoderma following Mpox in an HIV-positive patient.


Assuntos
Anetodermia , Infecções por HIV , Humanos , Masculino , Adulto , Anetodermia/patologia , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Combinação Trimetoprima e Sulfametoxazol/efeitos adversos , Combinação Trimetoprima e Sulfametoxazol/uso terapêutico
2.
Clin Exp Dermatol ; 49(2): 149-154, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-37847066

RESUMO

Diagnosis of pityriasis lichenoides et varioliformis acuta (PLEVA) is based on the characteristic pattern of lesions in different stages of development, ranging from erythematous maculopapules to papules with a crusted and/or necrotic centre. However, it may raise the differential diagnosis with other entities. It is therefore not uncommon to have to perform skin biopsies to reach a diagnosis, including in infants. In this study, we report the cases of three patients with PLEVA, highlighting the correlations between the clinical, dermoscopic and histological features. Observation of the dermatoscopic findings described, such as punctate or glomerular vessels and erythematous globules surrounding a homogeneous orange or crusty central area, may allow for a rapid diagnosis, avoiding the need for invasive techniques.


Assuntos
Pitiríase Liquenoide , Lactente , Humanos , Pitiríase Liquenoide/diagnóstico , Pitiríase Liquenoide/patologia , Dermoscopia , Pele/patologia , Diagnóstico Diferencial
3.
Glycoconj J ; 40(1): 47-67, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36522582

RESUMO

Glioblastoma multiforme (GBM) is the most aggressive type of glioma, displaying atypical glycosylation pattern that may modulate signaling pathways involved in tumorigenesis. Lectins are glycan binding proteins with antitumor properties. The present study was designed to evaluate the antitumor capacity of the Dioclea reflexa lectin (DrfL) on glioma cell cultures. Our results demonstrated that DrfL induced morphological changes and cytotoxic effects in glioma cell cultures of C6, U-87MG and GBM1 cell lines. The action of DrfL was dependent upon interaction with glycans, and required a carbohydrate recognition domain (CRD), and the cytotoxic effect was apparently selective for tumor cells, not altering viability and morphology of primary astrocytes. DrfL inhibited tumor cell migration, adhesion, proliferation and survival, and these effects were accompanied by activation of p38MAPK and JNK (p46/54), along with inhibition of Akt and ERK1/2. DrfL also upregulated pro-apoptotic (BNIP3 and PUMA) and autophagic proteins (Atg5 and LC3 cleavage) in GBM cells. Noteworthy, inhibition of autophagy and caspase-8 were both able to attenuate cell death in GBM cells treated with DrfL. Our results indicate that DrfL cytotoxicity against GBM involves modulation of cell pathways, including MAPKs and Akt, which are associated with autophagy and caspase-8 dependent cell death.


Assuntos
Antineoplásicos , Morte Celular Autofágica , Dioclea , Glioma , Humanos , Dioclea/química , Caspase 8/metabolismo , Caspase 8/farmacologia , Caspase 8/uso terapêutico , Lectinas/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-akt/farmacologia , Proteínas Proto-Oncogênicas c-akt/uso terapêutico , Linhagem Celular Tumoral , Glioma/tratamento farmacológico , Glioma/metabolismo , Glioma/patologia , Movimento Celular , Autofagia , Antineoplásicos/farmacologia , Proliferação de Células , Apoptose
4.
Clin Exp Dermatol ; 48(7): 781-784, 2023 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-36944551

RESUMO

Monkeypox is a rare zoonotic disease with a progressive increase in cases among men who have sex with men (MSM) worldwide in recent months. New complications of this infection have been described. The aim of the study was to describe this new pattern of presentation of monkeypox at the level of the finger. We present the cases of three patients with monkeypox whitlow, a new clinical presentation of monkeypox. The patients were three MSM with ages ranging from 32 to 49 years. All three had involvement of the third finger of the dominant hand as well as skin lesions at other sites. Two of the three patients had severe inflammation in the digit and proximal arm and were treated with systemic corticosteroids with significant improvement. In two of the three cases we observed onychodystrophy as a complication. All patients reported sexual intercourse with previous digital-anal penetration with the affected finger, which may be the mode of transmission. Distinguishing features that need to be considered are discussed.


Assuntos
Mpox , Doenças da Unha , Minorias Sexuais e de Gênero , Masculino , Humanos , Homossexualidade Masculina , Dedos , Doenças Raras
5.
Australas J Dermatol ; 64(1): e51-e56, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36598263

RESUMO

BACKGROUND: Syphilis is a sexually transmitted infection (STI) caused by the pathogen Treponema pallidum. Its incidence is increasing in our country, especially among men who have sex with men (MSM). Serological tests are still the most widely used technique for diagnosis. The need for an early diagnosis has prompted the introduction of fast techniques, such as Treponema pallidum detection by polymerase chain reaction (PCR) on mucocutaneous samples. The objective of this work is to analyse the sensitivity of this technique in a series of patients diagnosed with syphilis at our centre. METHODS: Retrospective review of all cases diagnosed with syphilis at our centre between May 2017 and May 2021. RESULTS: A total of 203 cases of syphilis were diagnosed with serologic tests: 33% were primary syphilis and 53.1% secondary syphilis. PCR for Treponema pallidum was performed in 117 (57,6%) cases. The sensitivity was highest (95,2%) when performed on samples from mucocutaneous ulcers in primary syphilis. This value decreased to 69,4% in secondary syphilis, although there were variations between the types of samples. CONCLUSIONS: The PCR test has a high diagnostic value when performed on ulcer exudates in patients with primary syphilis. Its most relevant advantages in clinical practice are the possibility of an early diagnosis before serological tests during the window period, the ability to confirm reinfections in patients with persistent positivity of reaginic antibodies and a history of treated syphilis. Nevertheless, given that a negative PCR test may not rule out infection by Treponema pallidum, serologic tests are still necessary for everyday practice.


Assuntos
Minorias Sexuais e de Gênero , Sífilis , Masculino , Humanos , Sífilis/diagnóstico , Sífilis/complicações , Treponema pallidum/genética , Homossexualidade Masculina , Sensibilidade e Especificidade , Reação em Cadeia da Polimerase/métodos , Úlcera
6.
J Cell Sci ; 133(12)2020 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-32409566

RESUMO

Functional recovery after peripheral nerve damage is dependent on the reprogramming of differentiated Schwann cells (dSCs) into repair Schwann cells (rSCs), which promotes axonal regeneration and tissue homeostasis. Transition into a repair phenotype requires expression of c-Jun and Sox2, which transcriptionally mediates inhibition of the dSC program of myelination and activates a non-cell-autonomous repair program, characterized by the secretion of neuronal survival and regenerative molecules, formation of a cellular scaffold to guide regenerating axons and activation of an innate immune response. Moreover, rSCs release exosomes that are internalized by peripheral neurons, promoting axonal regeneration. Here, we demonstrate that reprogramming of Schwann cells (SCs) is accompanied by a shift in the capacity of their secreted exosomes to promote neurite growth, which is dependent on the expression of c-Jun (also known as Jun) and Sox2 by rSCs. Furthermore, increased expression of miRNA-21 is responsible for the pro-regenerative capacity of rSC exosomes, which is associated with PTEN downregulation and PI3-kinase activation in neurons. We propose that modification of exosomal cargo constitutes another important feature of the repair program of SCs, contributing to axonal regeneration and functional recovery after nerve injury.


Assuntos
Exossomos , MicroRNAs , Axônios , Reprogramação Celular , Exossomos/genética , MicroRNAs/genética , Regeneração Nervosa/genética , Células de Schwann
7.
Sex Transm Dis ; 49(12): 858-859, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36111984

RESUMO

ABSTRACT: We describe 2 monkeypox cases in human immunodeficiency virus-positive men who have sex with men with undetectable viral loads. Both patients presented with the dory flop sign.


Assuntos
Mpox , Minorias Sexuais e de Gênero , Masculino , Humanos , Mpox/diagnóstico , Mpox/epidemiologia , Monkeypox virus , Homossexualidade Masculina , Carga Viral
8.
Mol Psychiatry ; 26(12): 7257-7269, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34316004

RESUMO

We demonstrate that the rate of extracellular signal-related kinase phosphorylation (P-ERK1,2/Total-ERK1,2) in the amygdala is negatively and independently associated with anxiety symptoms in 23 consecutive patients with drug-resistant mesial temporal lobe epilepsy that was surgically treated. In naive Wistar rats, the P-ERK1,2/Total-ERK1,2 ratio in the amygdala correlates negatively with innate anxiety-related behavior on the elevated plus maze (n = 20) but positively with expression of defensive-learned behavior (i.e., freezing) on Pavlovian aversive (fear) conditioning (n = 29). The microinfusion of ERK1/2 inhibitor (FR180204, n = 8-13/group) or MEK inhibitor (U0126, n = 8-9/group) into the basolateral amygdala did not affect anxiety-related behavior but impaired the evocation (anticipation) of conditioned-defensive behavior (n = 9-11/group). In conclusion, the P-ERK1,2/Total-ERK1,2 ratio in the amygdala predicts anxiety in humans and the innate anxiety- and conditioned freezing behaviors in rats. However, the ERK1/2 in the basolateral AMY is only required for the expression of defensive-learned behavior. These results support a dissociate ERK-dependent mechanism in the amygdala between innate anxiety-like responses and the anticipation of learned-defensive behavior. These findings have implications for understanding highly prevalent psychiatric disorders related to the defensive circuit manifested by anxiety and fear. HIGHLIGHTS: The P-ERK1,2/Total-ERK1,2 ratio in the amygdala (AMY) correlates negatively with anxiety symptoms in patients with mesial temporal lobe epilepsy. The P-ERK1,2/Total-ERK1,2 in the amygdala correlates negatively with the anxiety-like behavior and positively with freezing-learned behavior in naive rats. ERK1,2 in the basolateral amygdala is required for learned-defensive but not for the anxiety-like behavior expression in rats.


Assuntos
Tonsila do Cerebelo , Ansiedade , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Tonsila do Cerebelo/metabolismo , Animais , Ansiedade/metabolismo , Humanos , Proteína Quinase 1 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 3 Ativada por Mitógeno/antagonistas & inibidores , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Fosforilação , Ratos , Ratos Wistar
9.
Molecules ; 27(20)2022 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-36296679

RESUMO

A glioblastoma (GBM) is a highly malignant primary brain tumor with a poor prognosis because of its invasiveness and high resistance to current therapies. In GBMs, abnormal glycosylation patterns are associated with malignancy, which allows for the use of lectins as tools for recognition and therapy. More specifically, lectins can interact with glycan structures found on the malignant cell surface. In this context, the present work aimed to investigate the antiglioma potential of ConGF, a lectin purified from Canavalia grandiflora seeds, against C6 cells. The treatment of C6 cells with ConGF impaired the mitochondrial transmembrane potential, reduced cell viability, and induced morphological changes. ConGF also induced massive autophagy, as evaluated by acridine orange (AO) staining and LC3AB-II expression, but without prominent propidium iodide (PI) labeling. The mechanism of action appears to involve the carbohydrate-binding capacity of ConGF, and in silico studies suggested that the lectin can interact with the glycan structures of matrix metalloproteinase 1 (MMP1), a prominent protein found in malignant cells, likely explaining the observed effects.


Assuntos
Canavalia , Fabaceae , Canavalia/química , Fabaceae/química , Lectinas/química , Metaloproteinase 1 da Matriz , Propídio , Laranja de Acridina , Lectinas de Plantas/química , Sementes/química , Carboidratos/análise
10.
Mol Psychiatry ; 25(3): 655-665, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-29880883

RESUMO

Fear is a conscious state caused by exposure to real or imagined threats that trigger stress responses that affect the body and brain, particularly limbic structures. A sub-group of patients with mesial temporal lobe epilepsy related to hippocampus sclerosis (MTLE-HS) have seizures with fear, which is called ictal fear (IF), due to epileptic activity within the brain defensive survival circuit structures. Synaptic transmission efficacy can be bi-directionally modified through potentiation (long-term potentiation (LTP)) or depression (long-term depression (LTD)) as well as the phosphorylation state of Ser831 and Ser845 sites at the GluA1 subunit of the glutamate AMPA receptors, which has been characterized as a critical event for this synaptic plasticity. In this study, GluA1 levels and the phosphorylation at Ser845 and Ser831 in the amygdala (AMY), anterior hippocampus (aHIP) and middle gyrus of temporal neocortex (CX) were determined with western blots and compared between MTLE-HS patients who were showing (n = 06) or not showing (n = 25) IF. Patients with IF had an 11% decrease of AMY levels of the GluA1 subunit (p = 0.05) and a 21.5% decrease of aHIP levels of P-GluA1-Ser845 (p = 0.009) compared to patients not showing IF. The observed associations were not related to imbalances in the distribution of other concomitant types of aura, demographic, clinical or neurosurgical variables. The lower levels of P-GluA1-Ser845 in the aHIP of patients with IF were not related to changes in the levels of the serine/threonine-protein phosphatase PP1-alpha catalytic subunit or protein kinase A activation. Taken together, the GluA1 subunit levels in AMY and P-GluA1-Ser845 levels in the aHIP show an overall accuracy of 89.3% (specificity 95.5% and sensitivity 66.7%) to predict the presence of IF. AMY levels of the GluA1 subunit and aHIP levels of P-GluA1-Ser845 were not associated with the psychiatric diagnosis and symptoms of patients. Taken together with previous findings in MTLE-HS patients with IF who were evaluated by stereotactic implanted depth electrodes, we speculate our findings are consistent with the hypothesis that AMY is not a centre of fear but together with other sub-cortical and cortical structures integrates the defensive circuit that detect and respond to threats. This is the first report to address neuroplasticity features in human limbic structures connected to the defensive survival circuits, which has implications for the comprehension of highly prevalent psychiatric disorders and symptoms.


Assuntos
Medo/fisiologia , Receptores de Glutamato/genética , Convulsões/psicologia , Adulto , Tonsila do Cerebelo/metabolismo , Ansiedade/genética , Ansiedade/fisiopatologia , Transtornos de Ansiedade/metabolismo , Biomarcadores/metabolismo , Feminino , Ácido Glutâmico/metabolismo , Hipocampo/metabolismo , Humanos , Potenciação de Longa Duração , Masculino , Plasticidade Neuronal/fisiologia , Fosforilação , Receptores de AMPA/metabolismo , Receptores de Glutamato/metabolismo , Convulsões/metabolismo , Serina/metabolismo , Transmissão Sináptica
11.
Purinergic Signal ; 17(2): 285-301, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33712981

RESUMO

Guanosine is a purine nucleoside that has been shown to exhibit antidepressant effects, but the mechanisms underlying its effect are not well established. We investigated if the antidepressant-like effect induced by guanosine in the tail suspension test (TST) in mice involves the modulation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor, voltage-dependent calcium channel (VDCC), and brain-derived neurotrophic factor (BDNF)/tropomyosin receptor kinase B (TrkB) pathway. We also evaluated if the antidepressant-like effect of guanosine is accompanied by an acute increase in hippocampal and prefrontocortical BDNF levels. Additionally, we investigated if the ability of guanosine to elicit a fast behavioral response in the novelty suppressed feeding (NSF) test is associated with morphological changes related to hippocampal synaptogenesis. The antidepressant-like effect of guanosine (0.05 mg/kg, p.o.) in the TST was prevented by DNQX (AMPA receptor antagonist), verapamil (VDCC blocker), K-252a (TrkBantagonist), or BDNF antibody. Increased P70S6K phosphorylation and higher synapsin I immunocontent in the hippocampus, but not in the prefrontal cortex, were observed 1 h after guanosine administration. Guanosine exerted an antidepressant-like effect 1, 6, and 24 h after its administration, an effect accompanied by increased hippocampal BDNF level. In the prefrontal cortex, BDNF level was increased only 1 h after guanosine treatment. Finally, guanosine was effective in the NSF test (after 1 h) but caused no alterations in dendritic spine density and remodeling in the ventral dentate gyrus (DG). Altogether, the results indicate that guanosine modulates targets known to be implicated in fast antidepressant behavioral responses (AMPA receptor, VDCC, and TrkB/BDNF pathway).


Assuntos
Antidepressivos/farmacologia , Fator Neurotrófico Derivado do Encéfalo/efeitos dos fármacos , Guanosina/farmacologia , Glicoproteínas de Membrana/efeitos dos fármacos , Proteínas Tirosina Quinases/efeitos dos fármacos , Receptores de AMPA/agonistas , Transdução de Sinais/efeitos dos fármacos , Animais , Fator Neurotrófico Derivado do Encéfalo/biossíntese , Canais de Cálcio/efeitos dos fármacos , Espinhas Dendríticas/efeitos dos fármacos , Comportamento Alimentar/efeitos dos fármacos , Feminino , Elevação dos Membros Posteriores , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Glicoproteínas de Membrana/biossíntese , Camundongos , Neurogênese/efeitos dos fármacos , Córtex Pré-Frontal/efeitos dos fármacos , Córtex Pré-Frontal/metabolismo , Proteínas Tirosina Quinases/biossíntese , Sinapses/efeitos dos fármacos
12.
Metab Brain Dis ; 36(4): 711-722, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33528752

RESUMO

Fluoxetine is the foremost prescribed antidepressant. Drugs acting on monoaminergic system may also regulate glutamatergic system. Indeed, the investigation of proteins associated with this system, such as Narp (neuronal activity-dependent pentraxin) and GluA4 subunit of AMPA receptor may reveal poorly explored modulations triggered by conventional antidepressants. This study aimed to uncover neurochemical mechanisms underlying the chronic fluoxetine treatment, mainly by evaluating these protein targets in the prefrontal cortex and in the hippocampus. Mice received a daily administration of fluoxetine (0.1, 1 or 10 mg/kg, p.o.) or potable water (vehicle group) for 21 days. These animals were submitted to the forced swim test (FST) to verify antidepressant-like responses and the open-field test (OFT) to assess locomotor activity. Modulation of signaling proteins was analyzed by western blot. Chronic treatment with fluoxetine (1 and 10 mg/kg) was effective, since it reduced the immobility time in the FST, without altering locomotor activity. Fluoxetine 10 mg/kg increased CREB phosphorylation and BDNF expression in the prefrontal cortex and hippocampus. Noteworthy, in the hippocampus fluoxetine also promoted Akt activation and augmented Narp expression. In the prefrontal cortex, a significant decrease in the expression of the GluA4 subunit and Narp were observed following fluoxetine administration (10 mg/kg). The results provide evidence of novel molecular targets potentially involved in the antidepressant effects of fluoxetine, since in mature rodents Narp and GluA4 are mainly expressed in the GABAergic parvalbumin-positive (PV+) interneurons. This may bring new insights into the molecular elements involved in the mechanisms underlying the antidepressant effects of fluoxetine.


Assuntos
Antidepressivos de Segunda Geração/administração & dosagem , Proteína C-Reativa/antagonistas & inibidores , Sistemas de Liberação de Medicamentos/métodos , Fluoxetina/administração & dosagem , Proteínas do Tecido Nervoso/antagonistas & inibidores , Receptores de AMPA/antagonistas & inibidores , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Proteína C-Reativa/metabolismo , Relação Dose-Resposta a Droga , Masculino , Camundongos , Proteínas do Tecido Nervoso/metabolismo , Receptores de AMPA/metabolismo
13.
J Mol Recognit ; 33(11): e2870, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32648306

RESUMO

Lectins are a group of proteins of non-immune origin recognized for their ability to bind reversibly to carbohydrates. Researchers have been intrigued by oligosaccharides and glycoconjugates for their involvement as mediators of complex cellular events and then many biotechnological applications of lectins are based on glycocode decoding and their activities. Here, we report a structural and biological study of a ConA-like mannose/glucose-specific lectin from Canavalia bonariensis seeds, CaBo. More specifically, we evaluate the binding of CaBo with α-methyl-D-mannoside (MMA) and mannose-1,3-α-D-mannose (M13) and the resultant in vivo effects on a rat model of acute inflammation. A virtual screening was also carried out to cover a larger number of possible bindings of CaBo. In silico analysis demonstrated the stability of CaBo interaction with mannose-type ligands, and the lectin was able to induce acute inflammation in rats with the participation of the carbohydrate recognition domain (CRD) and histamine release. These results confirm the ability of CaBo to interact with hybrid and high-mannose N-glycans, supporting the hypothesis that CaBo's biological activity occurs primarily through its interaction with cell surface glycosylated receptors.


Assuntos
Carboidratos/química , Inflamação/tratamento farmacológico , Lectinas de Ligação a Manose/farmacologia , Lectinas de Plantas/farmacocinética , Animais , Sítios de Ligação , Histamina/farmacologia , Humanos , Inflamação/induzido quimicamente , Inflamação/patologia , Manose/química , Lectinas de Ligação a Manose/química , Manosídeos/química , Lectinas de Plantas/química , Lectinas de Plantas/farmacologia , Polissacarídeos/química , Ratos
15.
Neurochem Res ; 2019 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-31713091

RESUMO

Neuronal hippocampal death can be induced by exacerbated levels of cortisol, a condition usually observed in patients with Major depressive disorder (MDD). Previous in vitro and in vivo studies showed that ursolic acid (UA) elicits antidepressant and neuroprotective properties. However, the protective effects of UA against glucocorticoid-induced cytotoxicity have never been addressed. Using an in vitro model of hippocampal cellular death induced by elevated levels of corticosterone, we investigated if UA prevents corticosterone-induced cytotoxicity in HT22 mouse hippocampal derived cells. Concentrations lower than 25 µM UA did not alter cell viability. Co-incubation with UA for 48 h was able to protect HT22 cells from the reduction on cell viability and from the increase in apoptotic cells induced by corticosterone. Inhibition of protein kinase A (PKA), protein kinase C (PKC) and, Ca2+/calmodulin-dependent protein kinase II (CaMKII), but not phosphoinositide 3-kinase(PI3K), by using the pharmacological the inhibitors: H-89, chelerythrine, KN-62, and LY294002, respectively totally abolished the cytoprotective effects of UA. Finally, UA abrogated the reduction in phospho-extracellular signal-regulated kinases 1 and 2 (ERK1/2) but not in phospho-c-Jun kinases induced by corticosterone. These results indicate that the protective effect of UA against the cytotoxicity induced by corticosterone in HT22 cells may involve PKA, PKC, CaMKII, and ERK1/2 activation. The cytoprotective potential of UA against corticosterone-induced cytotoxicity and its ability to modulate intracellular signaling pathways involved in cell proliferation and survival suggest that UA may be a relevant strategy to manage stress-related disorders such as MDD.

16.
Purinergic Signal ; 15(4): 491-504, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31768875

RESUMO

Although guanosine is an endogenous nucleoside that displays antidepressant-like properties in several animal models, the mechanism underlying its antidepressant-like effects is not well characterized. The present study aimed at investigating the involvement of ERK/GSK-3ß and Nrf2/HO-1 signaling pathways in the antidepressant-like effect of guanosine in the mouse tail suspension test (TST). The immobility time in the TST was taken as an indicative of antidepressant-like responses and the locomotor activity was assessed in the open-field test. Biochemical analyses were performed by Western blotting in the hippocampus and prefrontal cortex (PFC). The combined treatment with sub-effective doses of guanosine (0.01 mg/kg, p.o.) and lithium chloride (a non-selective GSK-3ß inhibitor, 10 mg/kg, p.o.) or AR-A014418 (selective GSK-3ß inhibitor, 0.01 µg/site, i.c.v.) produced a synergistic antidepressant-like effect in the TST. The antidepressant-like effect of guanosine (0.05 mg/kg, p.o.) was completely prevented by the treatment with MEK1/2 inhibitors U0126 (5 µg/site, i.c.v.), PD98059 (5 µg/site, i.c.v.), or zinc protoporphyrin IX (ZnPP) (HO-1 inhibitor, 10 µg/site, i.c.v). Guanosine administration (0.05 mg/kg, p.o.) increased the immunocontent of ß-catenin in the nuclear fraction and Nrf2 in the cytosolic fraction in the hippocampus and PFC. The immunocontent of HO-1 was also increased in the hippocampus and PFC. Altogether, the results provide evidence that the antidepressant-like effect of guanosine in the TST involves the inhibition of GSK-3ß, as well as activation of MAPK/ERK and Nrf2/HO-1 signaling pathways, highlighting the relevance of these molecular targets for antidepressant responses.


Assuntos
Glicogênio Sintase Quinase 3 beta/efeitos dos fármacos , Guanosina/farmacologia , Heme Oxigenase-1/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Animais , Antidepressivos/farmacologia , Depressão/tratamento farmacológico , Depressão/metabolismo , Modelos Animais de Doenças , Comportamento Exploratório/efeitos dos fármacos , Feminino , Heme Oxigenase-1/metabolismo , Elevação dos Membros Posteriores/métodos , Hipocampo/metabolismo , Masculino , Ratos Wistar , Transdução de Sinais/fisiologia
18.
Mol Biol Rep ; 46(1): 751-762, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30511305

RESUMO

Selenium (Se) is an essential trace element for humans; its intake is needed to allow the proper synthesis of 25 different selenoproteins that are necessary to the normal functioning of several organs, including the brain. Accordingly, decreased Se levels have been associated with neurological disorders. In the present study, we investigated the potential beneficial effects of Se, as sodium selenite, against 3-nitropropionic acid (3-NP)-induced oxidative stress in primary cultures of mouse cortical neurons. 3-NP treatment caused a significant decrease in cellular viability, which was accompanied by decreases in mitochondrial complex II activity and reduced glutathione (GSH) content, as well as increases in reactive oxygen species (ROS) generation and oxidized glutathione (GSSG) levels. Sodium selenite pretreatment (6 days) attenuated 3-NP-induced decrease in cell viability. In addition, sodium selenite pretreatment significantly protected against 3-NP-induced increase in ROS generation and decrease in GSH/GSSG ratio. Of note, sodium selenite pretreatment did not change 3-NP-induced decrease of mitochondrial complex II activity, suggesting that Se modulates secondary events resultant from 3-NP-induced mitochondrial dyshomeostasis. In addition, sodium selenite pretreatment significantly increased glutathione peroxidase (GPx) activity. Our data provide insights into the mechanism of protection by sodium selenite, which is related, at least in part, to GPx induction.


Assuntos
Córtex Cerebral/patologia , Neurônios/patologia , Fármacos Neuroprotetores/farmacologia , Nitrocompostos/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Propionatos/toxicidade , Selenito de Sódio/farmacologia , Animais , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Glutationa Peroxidase/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fosforilação/efeitos dos fármacos
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