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1.
Environ Toxicol Pharmacol ; 106: 104388, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38355029

RESUMO

Embryonic development is exceptionally susceptible to pathogenic, chemistry and mechanical stressors as they can disrupt homeostasis, causing damage and impacted viability. Oxidative stress has the capacity to induce alterations and reshape the environment. However, the specific impacts of these oxidative stress-induced damages in the gastrointestinal tract of Drosophila melanogaster larvae have been minimally explored. This study used 2,2-azobis (2-amidinopropane) dihydrochloride (AAPH), a free radical generator, to investigate oxidative stress effects on Drosophila embryo development. The results showed that exposing Drosophila eggs to 30 mM AAPH during 1st instar larva, 2nd instar larva and 3rd instar larva stages significantly reduced hatching rates and pupal generation. It increased the activity of antioxidant enzymes and increased oxidative damage to proteins and MDA content, indicating severe oxidative stress. Morphological changes in 3rd individuals included decreased brush borders in enterocytes and reduced lipid vacuoles in trophocytes, essential fat bodies for insect metabolism. Immunostaining revealed elevated cleaved caspase 3, an apoptosis marker. This evidence validates the impact of oxidative stress toxicity and cell apoptosis following exposure, offering insights into comprehending the chemically induced effects of oxidative stress by AAPH on animal development.


Assuntos
Drosophila melanogaster , Estresse Oxidativo , Humanos , Animais , Larva , Amidinas
2.
Photochem Photobiol Sci ; 22(6): 1341-1356, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36867369

RESUMO

Prostate cancer is the most common cancer in American men, aside from skin cancer. As an alternative cancer treatment, photodynamic laser therapy (PDT) can be used to induce cell death. We evaluated the PDT effect, using methylene blue as a photosensitizer, in human prostate tumor cells (PC3). PC3 were subjected to four different conditions: DMEM (control); laser treatment (L-660 nm, 100 mW, 100 J.cm-2); methylene blue treatment (MB-25 µM, 30 min), and MB treatment followed by low-level red laser irradiation (MB-PDT). Groups were evaluated after 24 h. MB-PDT treatment reduced cell viability and migration. However, because MB-PDT did not significantly increase the levels of active caspase-3 and BCL-2, apoptosis was not the primary mode of cell death. MB-PDT, on the other hand, increased the acid compartment by 100% and the LC3 immunofluorescence (an autophagy marker) by 254%. Active MLKL level, a necroptosis marker, was higher in PC3 cells after MB-PDT treatment. Furthermore, MB-PDT resulted in oxidative stress due to a decrease in total antioxidant potential, catalase levels, and increased lipid peroxidation. According to these findings, MB-PDT therapy is effective at inducing oxidative stress and reducing PC3 cell viability. In such therapy, necroptosis is also an important mechanism of cell death triggered by autophagy.


Assuntos
Fotoquimioterapia , Neoplasias da Próstata , Masculino , Humanos , Fotoquimioterapia/métodos , Sobrevivência Celular , Azul de Metileno/farmacologia , Necroptose , Fármacos Fotossensibilizantes/farmacologia , Neoplasias da Próstata/tratamento farmacológico
3.
J Chem Neuroanat ; 129: 102253, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36841439

RESUMO

Benzodiazepine (BZD) abuse is a global problem, including pregnant women. For this population, the drug of choice is usually alprazolam, which acts as a GABAergic agonist and may compromise the development of integrative areas of the nervous system, such as the dentate gyrus (DG) of the hippocampus. In this context, we studied the changes in the DG of the offspring of rats treated with alprazolam during gestation: control, treatment 1 (T1: 1.25 mg/animal), and an overdose group (T2: 30 mg/animal). Alprazolam was administered orally ten days before mating and during the gestational period. After birth, newborns were counted, sexed, and the body mass of each pup was measured. The newborns' brains were extracted and processed for morphological study of the DG or for total protein extraction of the hippocampus. The results showed that alprazolam can affect the cell number and area, and increased euchromatin in both granular and molecular layers of the DG, especially in the overdose group. Also, alprazolam upregulated the NF-κB and reduced GFAP and caspase-3. Based on our findings, we conclude that the DG is a plausible region of influence by BZDs during embryogenesis. An overdose during gestation may cause structural changes in the DG.


Assuntos
Giro Denteado , Masculino , Feminino , Animais , Ratos , Ratos Wistar , Alprazolam/farmacologia , Giro Denteado/efeitos dos fármacos , Giro Denteado/metabolismo , Gravidez , Peso Corporal , Proliferação de Células , Tamanho Celular , NF-kappa B/metabolismo , Peroxidação de Lipídeos
4.
Int J Dev Neurosci ; 82(8): 727-735, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35916248

RESUMO

The use of benzodiazepines (BZDs) during pregnancy, especially alprazolam, is common and its impact on the fetal neural tissue is not known. In this sense, the present study aimed to investigate the effects of prenatal treatment with alprazolam on the cerebellum of Wistar rat pups. Thirty animals (24 females and six males, CEUA protocol 014/17) were separated into pairs for copulation. Females were divided into three groups: Control (CT), treatment 1 (T1, 1.25 mg per animal), and treatment 2, which is an overdose (T2, 30 mg per animal). Alprazolam was administered 10 days before copulation and throughout pregnancy. We evaluated the number and weight of pups and the macroscopic changes in the brain. Eight neonates (n = 8) from each group were used in the following analyses: Cellular and chromatin density, gliosis, synaptic density, inflammation, and oxidative stress. The results showed no significant differences regarding the number of pups, body weight, and macroscopic changes. The morphological study focused on the external granular layer (EGL) that is presented only in the immature cerebellum. Here, we detected more cells after alprazolam treatment; the T2 group showed large nuclei and some pyknotic nuclei; also, both treated groups presented an increase in the euchromatin density compared with the control. The molecular and biochemical analyses used the total protein extract of the entire cerebellum and showed an increased expression of Iba-1 and NF-κBp65 but without indication of inflammation or degeneration in the T1 group. Overdose of alprazolam presented an increased level of oxidative degradation of lipids. The treatment with alprazolam during pregnancy involved cellular and molecular changes in the immature cerebellum.


Assuntos
Alprazolam , Cerebelo , Gravidez , Masculino , Feminino , Animais , Ratos , Alprazolam/toxicidade , Ratos Wistar , Encéfalo , Inflamação
5.
Brain Res Bull ; 174: 53-62, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34090933

RESUMO

Surgical intervention is necessary following nerve trauma. Tubular prostheses can guide growing axons and inserting substances within these prostheses can be positive for the regeneration, making it an alternative for the current standard tools for nerve repair. Our aim was to investigate the effects of fibrin glue BthTL when combined with a synthetic TNF mimetic-action peptide on nerve regeneration. Male Wistar rats suffered left sciatic nerve transection. For repairing, we used empty silicon tubes (n = 10), tubes filled with fibrin glue BthTL (Tube + Glue group, n = 10) or tubes filled with fibrin glue BThTL mixed with TNF mimetic peptide (Tube + Glue + Pep group, n = 10). Animals were euthanized after 45 days. We collected nerves to perform immunostaining (neurofilament, GAP43, S100-ß, NGFRp75 and Iba-1), light and transmission electron microscopy (for counting myelinated, unmyelinated and degenerated fibers; and for the evaluation of morphometric aspects of regenerated fibers) and collagen staining. All procedures were approved by local ethics committee (protocol 063/17). Tube + Glue + Pep group showed intense inflammatory infiltrate, higher Iba-1 expression, increased immunostaining for NGFRp75 receptor (which characterizes Schwann cell regenerative phenotype), higher myelin thickness and fiber diameter and more type III collagen deposition. Tube + Glue group showed intermediate results between empty tube and Tube + Glue + Pep groups for anti-NGFRp75 immunostaining, inflammation and collagen; on fiber counts, this group showed more degenerate fibers and fewer unmyelinated axons than others. Empty tube group showed superiority only in GAP43 immunostaining. A combination of BthTL glue and TNF mimetic peptide induced greater axonal regrowth and remyelination.


Assuntos
Adesivo Tecidual de Fibrina , Regeneração Nervosa/efeitos dos fármacos , Peptidomiméticos/administração & dosagem , Peptidomiméticos/farmacologia , Nervos Periféricos/efeitos dos fármacos , Fator de Necrose Tumoral alfa/administração & dosagem , Fator de Necrose Tumoral alfa/farmacologia , Animais , Axônios/efeitos dos fármacos , Colágeno/metabolismo , Imuno-Histoquímica , Masculino , Bainha de Mielina/efeitos dos fármacos , Fibras Nervosas Mielinizadas/efeitos dos fármacos , Proteínas do Tecido Nervoso/metabolismo , Peptidomiméticos/química , Ratos , Ratos Wistar , Células de Schwann/efeitos dos fármacos , Células de Schwann/ultraestrutura , Nervo Isquiático/lesões , Fator de Necrose Tumoral alfa/química
6.
Front Immunol ; 11: 1010, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32655546

RESUMO

Trypanosoma cruzi P21 protein (P21) is a putative secreted and immunomodulatory molecule with potent bioactive properties such as induction of phagocytosis and actin cytoskeleton polymerization. Despite the bioactive properties described so far, the action of P21 on parasite replication in muscle cell lineage or T. cruzi parasitism during acute experimental infection is unclear. We observed that recombinant P21 (rP21) decreased the multiplication of T. cruzi in C2C12 myoblasts, phenomenon associated with greater actin polymerization and IFN-γ and IL-4 higher expression. During experimental infection, lower cardiac nests, inflammatory infiltrate and fibrosis were observed in mice infected and treated with rP21. These results were correlated with large expression of IFN-γ counterbalanced by high levels of IL-10, which was consistent with the lower cardiac tissue injury found in these mice. We have also observed that upon stress, such as that induced by the presence of the IFN-γ cytokine, T. cruzi produced more P21. The effect of P21 in controlling the replication of T. cruzi, may indicate an evolutionary mechanism of survival developed by the parasite. Thus, when subjected to different stress conditions, the protozoan produces more P21, which induces T. cruzi latency in the host organism, enabling the protozoan to evade the host's immune system.


Assuntos
Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Malária/parasitologia , Mioblastos/parasitologia , Miocárdio/patologia , Proteínas de Protozoários/metabolismo , Trypanosoma cruzi/fisiologia , Doença Aguda , Animais , Linhagem Celular , Interações Hospedeiro-Parasita , Humanos , Evasão da Resposta Imune , Peptídeos e Proteínas de Sinalização Intercelular/genética , Interferon gama/metabolismo , Malária/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Modelos Animais , Carga Parasitária , Proteínas de Protozoários/genética
7.
Reproduction ; 160(3): 469-480, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32520720

RESUMO

The prostate development has an important postnatal period where cell proliferation begins at the first days after birth and is related to gland growth and ramification. Any metabolic and/or hormonal changes occurring during the postnatal period can interfere with prostate branching. Hyperglycemia is a common condition in low-weight preterm babies at neonatal period and also a disorder found in the offspring of obese mothers. Thus, this study aimed to investigate the in vitro effects of a glucose-rich environment during prostate postnatal development. Wistar rats prostate were removed at birth and cultured for 1, 2 and 3 days in DMEM under normal (5.5 mM) or elevated (7 and 25 mM) glucose concentrations. Samples were processed for morphological analysis, PCNA and smooth muscle α-actin immunohistochemistry, evaluation of active caspase-3, ERK1/2 and Wnt5a gene expression. High glucose concentrations reduced the number of prostatic buds and proliferating cells. The natural increase in smooth muscle cells and collagen deposition observed in control prostates during the first 3 days of development was reduced by elevated glucose concentrations. The amount of active caspase-3 was higher in prostates incubated at 7 mM and TGF-ß levels also increased sharply after both glucose concentrations. Additionally, high glucose environment decreased ERK 1/2 activation and increased Wnt5a expression. These data show that high levels of glucose during the first postnatal days affected prostate development by inhibiting cell proliferation which impairs bud branching and this was associated with anti-proliferative signals such as decreased ERK1/2 activation and increased Wnt5a expression.


Assuntos
Regulação da Expressão Gênica/efeitos dos fármacos , Glucose/toxicidade , Próstata/patologia , Transdução de Sinais , Animais , Animais Recém-Nascidos , Proliferação de Células , Técnicas In Vitro , Masculino , Próstata/efeitos dos fármacos , Próstata/crescimento & desenvolvimento , Próstata/metabolismo , Ratos , Ratos Wistar , Edulcorantes/toxicidade
8.
Peptides ; 129: 170329, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32437718

RESUMO

The peptide angiotensin-(1-7) [Ang (1-7)] and its receptor Mas are involved in controlling arterial pressure and display actions on the nervous system. In a previous study, our laboratory showed that A779 [(peptidyl antagonist of the Ang-(1-7)] treatment had a negative effect following a lesion of the sciatic nerve, possibly by delaying the responses of Schwann cells, resulting in a decreased axonal organization along with a slowed functional return. In the present work, we investigated the central cellular changes after sciatic nerve injury in rodents treated with A779 after two weeks. In the lumbar spinal cords, where the neuronal bodies that make up the sciatic are, the treatment with A779 showed reduced reactivity of astrocytes (p = 0.004, Mann-Whitney U test) and less synaptic density (p = 0.004, Mann-Whitney U test) after injury. Also, the treatment upregulated microglia activity in both sides (p = 0.004, Mann-Whitney U test), ipsilateral and contralateral to the lesion, of the spinal cord. In addition, the Mas expression in spine neurons was increased in response to axotomy especially after two weeks (p = 0.03, Mann-Whitney U test) following the nerve lesion in comparison to earlier stages after injury. Therefore, we can conclude that Ang-(1-7)/Mas axis plays a role during spinal cord recovery after peripheral nerve injury.


Assuntos
Angiotensina II/análogos & derivados , Angiotensina I/agonistas , Axotomia , Gliose/tratamento farmacológico , Gliose/patologia , Fragmentos de Peptídeos/agonistas , Fragmentos de Peptídeos/uso terapêutico , Receptores Acoplados a Proteínas G/agonistas , Sinapses/efeitos dos fármacos , Angiotensina II/uso terapêutico , Animais , Astrócitos/efeitos dos fármacos , Imunofluorescência , Masculino , Camundongos Endogâmicos C57BL , Microglia/efeitos dos fármacos , Medula Espinal/efeitos dos fármacos
9.
J Chem Neuroanat ; 103: 101713, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31726089

RESUMO

The arcuate and the paraventricular and lateral hypothalamic nuclei, related to hunger and satiety control, are generally compromised by excess fatty acids. In this situation, fatty acids cause inflammation via TLR4 (toll like receptor 4) and the nuclei become less responsive to the hormones leptin and insulin, contributing to the development of obesity. In this work, these nuclei were analyzed in animals fed with high-fat diet and submitted to swimming without and with load for two months. For this, frontal sections of the hypothalamus were immunolabelled with GFAP (glial fibrillary acidic protein), synaptophysin, IL-6 (interleukin 6) and TLR4. Also, proteins extracted from the hypothalamus were analyzed using Western blotting (GFAP and synaptophysin), fluorometric analysis for caspases 3 and 7, and CBA (cytometric bead array) for Th1, Th2, and Th17 profiles. The high-fat diet significantly caused overweight and, in the hypothalamus, decreased synapses and increased astrocytic reactivity. The swimming with load, especially 80 % of the maximum load, reduced those consequences. The high-fat diet increased TLR4 in the arcuate nucleus and the swimming exercise with 80 % of the maximum load showed a tendency of reducing this expression. Swimming did not significantly influence the inflammatory or anti-inflammatory cytokines in the hypothalamus or in plasma. The high-fat diet in sedentary animals increased the expression of caspases 3 and 7 and swimming practice reduced this increment to levels compatible with animals fed on a normal diet. The set of results conclude that the impact of swimming on the damage caused in the hypothalamus by a high-fat diet is positive. The different aspects analyzed in here point to better cellular viability and conservation of the synapses in the hypothalamic nuclei of overweight animals that practiced swimming with a load.


Assuntos
Dieta Hiperlipídica/efeitos adversos , Hipotálamo/metabolismo , Neurônios/metabolismo , Sobrepeso/metabolismo , Natação/fisiologia , Animais , Caspases/metabolismo , Proteína Glial Fibrilar Ácida/metabolismo , Interleucina-6/metabolismo , Masculino , Camundongos , Sobrepeso/etiologia , Sinaptofisina/metabolismo , Receptor 4 Toll-Like/metabolismo
10.
Cell Biol Int ; 43(4): 373-383, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30353973

RESUMO

Recent studies have been trying to find out how diet and metabolic changes such as dyslipidaemia, hyperglycaemia, and hyperinsulinaemia can stimulate cancer progression. This investigation aimed to evaluate the effect of high concentrations of fatty acids and/or glucose in tumour prostate cells, focusing on the proliferation/migration profile and oxidative stress. PC3 cells were treated with high concentration of saturated fatty acid (palmitate, 100 µM), glucose (220 mg/dL), or both for 24 or 48 h. Results demonstrated that PC3 cells showed a significant increase in proliferation after 48 h of treatment with glucose and palmitate+glucose. Cell proliferation was associated with reduced levels of AMPK phosphorylation in glucose group at 24 and 48 h of treatment, while palmitate group presented this result only after 48 h of treatment. Also, there was a significant increase in cell migration between time 0 and 48 h after all treatments, except in the control. Catalase activity was increased by palmitate in the beginning of treatment, while glucose presented a later effect. Also, nitrite production was increased by glucose only after 48 h, and the total antioxidant activity was enhanced by palmitate in the initial hours. Thus, we conclude that the high concentration of the saturated fatty acid palmitate and glucose in vitro influences PC3 cells and stimulates cellular activities related to carcinogenesis such as cell proliferation, migration, and oxidative stress in different ways. Palmitate presents a rapid and initial effect, while a glucose environment stimulates cells later on, maintaining high levels of cell proliferation.


Assuntos
Glucose/metabolismo , Palmitatos/metabolismo , Neoplasias da Próstata/metabolismo , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Ácidos Graxos/metabolismo , Glucose/efeitos adversos , Glucose/fisiologia , Humanos , Hiperinsulinismo/metabolismo , Insulina/metabolismo , Masculino , Células PC-3/efeitos dos fármacos , Palmitatos/farmacologia , Fosforilação , Próstata/metabolismo
11.
Neurochem Int ; 120: 140-148, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30138641

RESUMO

Excessive fat consumption increases the level of fatty acids (FAs) in the blood, which reach the hypothalamus and damage the circuit related to energy balance. In the present study, we used palmitate in a primary culture of purified astrocytes to mimic the fat-rich environment found in obesity. Our results showed increased glial fibrillary acidic protein (GFAP) reactivity in hypothalamic astrocytes compared to cortical astrocytes. In addition, palmitate-treated astrocytes showed no significant changes in cytokine expression and an upregulation of glutathione in the culture medium that may serve as an intrinsic neuroprotective property against excess FA. Additionally, purified hypothalamic neurons were incubated with palmitate-treated astrocyte-conditioned medium (MPAL). MPAL treated-neurons exhibited a reduction in excitatory synapses and enhanced neuritogenesis. Our results suggest that hypothalamic astrocytes react to palmitate differently than cortical astrocytes and influence the behavior of the neural network related to energy balance. Our work brings a better understanding of the interactions among hypothalamic neurons in a high FA environment, similarly to obesity induced by a high-fat diet.


Assuntos
Astrócitos/efeitos dos fármacos , Meios de Cultivo Condicionados/farmacologia , Hipotálamo/efeitos dos fármacos , Palmitatos/farmacologia , Sinapses/efeitos dos fármacos , Animais , Astrócitos/metabolismo , Células Cultivadas , Proteína Glial Fibrilar Ácida/metabolismo , Glutationa/metabolismo , Hipotálamo/metabolismo , Camundongos , Neurônios/metabolismo , Sinapses/metabolismo
12.
Peptides ; 96: 15-19, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28870798

RESUMO

Angiotensin-(1-7) (Ang [1-7]) and its receptor Mas are involved in a number of physiological processes, including control of arterial pressure and modulation of nervous system actions. However, the involvement of the Ang-(1-7)/Mas axis in peripheral nerve injury has not been investigated. Using a model of sciatic nerve injury in mice, we demonstrated opposing changes in Mas receptor expression at days 2 and 14 post-injury. Mas receptor expression was more intense 2days after the nerve lesion, compared with the intensity of the intact nerve. At this time point, the sciatic nerve functional index was -20. At day 14 after the lesion, the intensity of the immunostaining labeling in longitudinal sections of the nerve was reduced (∼30%) and the functional index increased +36 (gait improvement). In the axotomized group treated with A779 (a Mas receptor antagonist), the functional recovery index decreased in relation to the untreated axotomized group. The Mas receptor inhibitor also altered the intensity of labeling of S-100, GAP43, and IBA-1 (morphological features compatible with delayed axon growth). This study demonstrated that Ang-(1-7)/Mas axis activity was differentially modulated in the acute and post-acute stages of nerve injury.


Assuntos
Nervos Periféricos/efeitos dos fármacos , Nervos Periféricos/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Neuropatia Ciática/metabolismo , Angiotensina II/análogos & derivados , Angiotensina II/farmacologia , Animais , Proteína GAP-43/metabolismo , Masculino , Camundongos , Fragmentos de Peptídeos/farmacologia , Nervos Periféricos/patologia , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Proteínas S100/metabolismo
13.
J Exerc Rehabil ; 13(3): 284-291, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28702439

RESUMO

This study examined physiological variables of animals fed with a high-fat diet (HFD) or with a normal diet (ND) subjected to swimming at low and moderate level. Over 16 weeks, a group of animals was fed with HFD or ND, and at the 8 weeks, they started swimming with 50% or 80% of the maximum load achieved in the progressive work test. Weekly, body weight and the amount of ingested food were registered. The glycemic level was measured at the beginning, middle and at the end of the experiment. Adipose tissue, gastrocnemius muscles and hearts were collected for morphometry. The results showed that the animals fed an HFD had a minor caloric intake; however, the HFD increased body weight and adiposity, likely causing cardiac hypertrophy and an increase in the glycemic level. In this context, swimming with an 80% load contributed positively to weight control, adiposity, glycemic level, to control cardiac hypertrophy and induce hypertrophy in the gastrocnemius muscle. All parameters assessed showed better results for the ND animals. Therefore, the importance of fat consumption was emphasized in relation to obesity onset. The practice of swimming with an 80% load produced greater benefits than swimming with a 50% load for overweight treatment.

14.
Virus Res ; 217: 92-100, 2016 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-26975980

RESUMO

St. Louis encephalitis virus (SLEV), a flavivirus transmitted to humans by Culex mosquitoes, causes clinical symptoms ranging from acute febrile disorder to encephalitis. To reach the central nervous system (CNS) from circulating blood, the pathogen must cross the blood-brain barrier formed by endothelial cells and astrocytes. Because astrocytes play an essential role in CNS homeostasis, in this study these cells were infected with SLEV and investigated for astrogliosis, major histocompatibility complex (MHC)-I-dependent immune response, and apoptosis by caspase-3 activation. Cultures of Vero cells were used as a positive control for the viral infection. Cytopathic effects were observed in both types of cell cultures, and the cytotoxicity levels of the two were compared. Astrocytes infected with a dilution of 1E-01 (7.7E+08 PFU/mL) had a reduced mortality rate of more than 50% compared to the Vero cells. In addition, the astrocytes responded to the flavivirus infection with increased MHC-I expression and astrogliosis, characterized by intense glial fibrillary acidic protein expression and an increase in the number and length of cytoplasmic processes. When the astrocytes were exposed to higher viral concentrations, a proportional increase in caspase-3 expression was observed, as well as nuclear membrane destruction. SLEV immunostaining revealed a perinuclear location of the virus during the replication process. Together, these results suggest that mechanisms other than SLEV infection in astrocytes must be associated with the development of the neuroinvasive form of the disease.


Assuntos
Astrócitos/virologia , Vírus da Encefalite de St. Louis/fisiologia , Animais , Morte Celular , Células Cultivadas , Chlorocebus aethiops , Camundongos , Células Vero
15.
Neurosci Lett ; 513(2): 223-8, 2012 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-22387456

RESUMO

It has been demonstrated that the major histocompatibility complex of class I (MHC I) up regulation by exogenous treatment with interferon beta (IFNbeta) influences the glial reaction and synaptic elimination process. Therefore, the present study aimed to investigate the effects of IFNbeta treatment on the expression of MHC I, CD3-zeta (a subunit of MHC I receptor) and synaptic formation in PC12 cells, an in vitro model for studying the synaptic formation/elimination process. For this purpose, established cultures were subjected to IFNbeta (500 and 1000IU/ml) treatment for 5, 10 and 15 days. The cells were then fixed and processed for immunocytochemistry with antisera against MHC I (OX18), CD3-zeta and synaptophysin. The results were compared with control cultures only treated with basal medium. IFNbeta (500IU/ml) modulated the MHC I expression in PC12 cells, especially after 10 days of treatment. In this sense, IFNbeta induced MHC I as well as CD3-zeta up regulation. It was observed that the highest dose caused culture degeneration. Interestingly, differential regulation of MHC I was paralleled by enhancement in synaptic network remodeling. Altogether, the present data indicate that PC12 cells may be used as an in vitro model for studying MHC I modulation and synaptic plasticity. It also reinforced the role of IFNbeta on the synaptic elimination process.


Assuntos
Complexo CD3/metabolismo , Antígenos de Histocompatibilidade Classe I/metabolismo , Interferon beta/farmacologia , Animais , Células PC12 , Ratos , Sinaptofisina/metabolismo , Regulação para Cima/efeitos dos fármacos
16.
Coluna/Columna ; 9(2): 193-198, abr.-jun. 2010. ilus
Artigo em Português | LILACS | ID: lil-557028

RESUMO

Foi demonstrado recentemente que o complexo de histocompatibilidade principal de classe I (MHC I), expresso no sistema nervoso central (SNC), não funciona somente como molécula com papel imunológico, mas também como parte de um mecanismo envolvido na plasticidade sináptica. A expressão de MHC I interfere na intensidade e seletividade da retração de sinapses em contato com neurônios que sofreram lesão e também influencia a reatividade das células gliais próximas a esses neurônios. A intensidade do rearranjo sináptico e resposta glial após lesão, ligadas à expressão de MHC I no SNC, repercute em diferenças na capacidade regenerativa e recuperação funcional em linhagens de camundongos isogênicos. Dessa forma, os novos aspectos sobre a função do MHC I no SNC direcionam futuras pesquisas no sentido de buscar o envolvimento do MHC I em doenças neurológicas e também o desenvolvimento de novas estratégias terapêuticas.


It has been recently demonstrated that the major histocompatibility complex of class I (MHC I) expressed in the central nervous system (CNS) does not only function as a molecule of the immune system, but also plays a role in the synaptic plasticity. The expression of MHC I influences the intensity and selectivity of elimination of synapses apposed to neurons that were subjected to lesion, besides influencing the reactivity of neighboring glial cells. MHC I expression and the degree of synaptic rearrangement and glial response after injury correlate with differences in the regenerative potential and functional recovery of isogenic mice strains. In this way, the new aspects regarding MHC I functions in the CNS may guide further studies aiming at searching the involvement of MCH I in neurologic disorders, as well as the development of new therapeutic strategies.


El complejo mayor de histocompatibilidad de clase I (MHC I), expresado en el sistema nervioso central (SNC), no sólo funciona como una molécula con función inmunológica, sino que es crucial para las respuestas del tejido nervioso en casos de lesiones. El MHC I está involucrado con los procesos de plasticidad sináptica y las células gliales en el microambiente de la médula espinal después de realizada axotomía periférica. La expresión de MHC I interfiere con la intensidad y la forma en que se producen la contracción y la eliminación de sinapsis con relación a las neuronas, cuyos axones se han comprometido, y también influye en la reactividad de las células gliales, cerca de estas neuronas. La intensidad de estos cambios, que responden a la expresión de MHC I en el SNC, implica diferencias en la capacidad de regeneración axonal de las células dañadas por axotomía, por lo que el nivel de expresión de las moléculas MHC I se relaciona con el proceso de regeneración de los axones y, en consecuencia, con la recuperación funcional. Por consiguiente, estos nuevos aspectos sobre la función del MHC I en el SNC orientan nuevas investigaciones con miras a entender el papel del MHC I en las enfermedades neurológicas y a desarrollar nuevas estrategias terapéuticas.


Assuntos
Axônios , Axotomia , Complexo Principal de Histocompatibilidade , Plasticidade Neuronal , Medula Espinal , Sinapses
17.
Neurosci Lett ; 451(1): 34-9, 2009 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-19103252

RESUMO

Avulsion of ventral roots induces degeneration of most axotomized motoneurons. At present there are no effective strategies to prevent such neuronal loss and to preserve the affected spinal circuits. Interestingly, changes in the spinal cord network also occur during the course of the experimental model of multiple sclerosis (experimental autoimmune encephalomyelitis-EAE). Glatiramer acetate (GA) significantly reduces the seriousness of the symptoms during the exacerbation of EAE. However, little is known about its effects on motoneurons. In the present study, we investigated whether GA has an influence on synapse plasticity and glial reaction after ventral root avulsion (VRA). Lewis rats were subjected to the avulsion of lumbar ventral roots and treated with GA. The animals were sacrificed after 14 days of treatment and the spinal cords processed for immunohistochemistry. A correlation between the synaptic changes and glial activation was obtained by performing immunolabeling against synaptophysin, GFAP and Iba-1. GA treatment preserved synaptophysin labeling, and significantly reduced the glial reaction in the area surrounding the axotomized motoneurons. After ventral root avulsion, GA treatment was also neuroprotective. The present results indicate that the immunomodulator GA has an influence on the stability of nerve terminals in the spinal cord, which may in turn contribute to future treatment strategies after proximal lesions to spinal motoneurons.


Assuntos
Neurônios Motores/efeitos dos fármacos , Degeneração Neural/tratamento farmacológico , Plasticidade Neuronal/efeitos dos fármacos , Peptídeos/farmacologia , Rizotomia/efeitos adversos , Medula Espinal/efeitos dos fármacos , Animais , Biomarcadores/análise , Biomarcadores/metabolismo , Proteínas de Ligação ao Cálcio/análise , Proteínas de Ligação ao Cálcio/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Citoproteção/efeitos dos fármacos , Citoproteção/fisiologia , Modelos Animais de Doenças , Acetato de Glatiramer , Proteína Glial Fibrilar Ácida/análise , Proteína Glial Fibrilar Ácida/metabolismo , Gliose/tratamento farmacológico , Gliose/fisiopatologia , Gliose/prevenção & controle , Imuno-Histoquímica , Imunossupressores/farmacologia , Imunossupressores/uso terapêutico , Proteínas dos Microfilamentos , Neurônios Motores/patologia , Degeneração Neural/fisiopatologia , Degeneração Neural/prevenção & controle , Plasticidade Neuronal/fisiologia , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Peptídeos/uso terapêutico , Ratos , Ratos Endogâmicos Lew , Medula Espinal/patologia , Medula Espinal/fisiopatologia , Raízes Nervosas Espinhais/lesões , Raízes Nervosas Espinhais/patologia , Raízes Nervosas Espinhais/fisiopatologia , Sinaptofisina/análise , Sinaptofisina/metabolismo
18.
Brain Res ; 1238: 23-30, 2008 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-18775685

RESUMO

Associated with neuronal death, profound synaptic changes occur in the spinal cord during the apoptotic process triggered after axotomy in neonatal rats. With respect to this, the major histocompatibility complex of class I (MHC class I) has recently emerged as a new mechanism related to synaptic stripping and plasticity. The present study investigated the impact of upregulating MHC class I expression by treatment with beta interferon (beta INF) on motoneuron survival, synaptic plasticity and astrogliosis after neonatal sciatic nerve injury. P2 rats were subjected to unilateral axotomy followed by three days of beta INF treatment. The results were analyzed by counting Nissl stained motoneurons, immunohistochemistry (anti-synaptophysin, MHC class I, GFAP and Iba-1) and transmission electron microscopy. INF treatment induced an increased expression of MHC class I, which resulted in a stronger synaptic elimination process in the spinal cord, as seen by the synaptophysin labeling. GFAP and Iba-1 upregulation were not significantly altered by the INF treatment, displaying the same degree of enhanced reactivity as compared to the placebo group. The ultrastructural analysis showed that, apart from the overall reduction of inputs in the neuropil, no statistical differences were present when comparing the INF and placebo treated animals. Also, neuronal survival was not altered by cytokine administration. The present results provide evidence that MHC class I upregulation after neonatal injury does not change the fate of lesioned motoneurons. In this way, the lack of neurotrophic support may cause broader synaptic loss, which superposes the more subtle effects of the upregulation of MHC class I.


Assuntos
Sobrevivência Celular/fisiologia , Antígenos de Histocompatibilidade Classe I/metabolismo , Neurônios Motores/metabolismo , Neurônios Motores/ultraestrutura , Plasticidade Neuronal/fisiologia , Animais , Animais Recém-Nascidos , Axotomia , Proteínas de Ligação ao Cálcio/efeitos dos fármacos , Proteínas de Ligação ao Cálcio/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Proteína Glial Fibrilar Ácida/efeitos dos fármacos , Proteína Glial Fibrilar Ácida/metabolismo , Gliose/metabolismo , Gliose/patologia , Antígenos de Histocompatibilidade Classe I/efeitos dos fármacos , Imuno-Histoquímica , Fatores Imunológicos/farmacologia , Interferon beta/farmacologia , Proteínas dos Microfilamentos , Microscopia Eletrônica de Transmissão , Neurônios Motores/efeitos dos fármacos , Plasticidade Neuronal/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Nervo Isquiático/lesões , Nervo Isquiático/fisiologia , Medula Espinal/efeitos dos fármacos , Medula Espinal/metabolismo , Medula Espinal/ultraestrutura , Sinaptofisina/efeitos dos fármacos , Sinaptofisina/metabolismo , Regulação para Cima
19.
Acta ortop. bras ; 14(3): 137-140, 2006. tab, graf
Artigo em Português, Inglês | LILACS | ID: lil-437769

RESUMO

Neste trabalho avaliou-se a eficácia do ultra-som contínuo e alta intensidade como tratamento na fasciíte plantar. Foram avaliadas 22 pessoas, com dor a mais de seis meses, através de questionário funcional e escala visual para a dor no primeiro apoio matinal. Vinte e sete pés foram distribuídos nos grupos: grupo 1 (alongamento + ultra-som desligado) e grupo 2 (alongamento + ultra-som 2 w/cm²). Após 15 sessões de tratamento, foi realizada análise dos valores absolutos e das porcentagens de melhora das variáveis coletadas. Houve melhora funcional para os dois grupos, sem diferença entre eles. A análise dos valores absolutos de intensidade de dor (primeira, oitava e última sessão) mostrou semelhança entre os grupos. A porcentagem de melhora nas 15 sessões não apresentou diferença entre os grupos. Esta porcentagem também foi calculada para dois períodos (antes e após a oitava sessão). Notou-se que a porcentagem de melhora das 15 sessões do grupo2 (46,5 por cento) foi inferior à porcentagem das oito primeiras sessões do grupo1 (54,6 por cento). Portanto, o ultra-som contínuo com alta intensidade não acrescentou ganhos em relação à função e à dor; além disso, apenas a realização de alongamentos específicos foi eficaz para a redução de mais de 50 por cento da dor na fasciíte plantar crônica.


In this study, the efficiency of continuous high-power ultrasound was assessed for plantar fasciitis treatment. Twenty two individuals were assessed, reporting pain lasting more than six months, through a functional questionnaire and visual scale for pain at the first morning load. Twenty seven feet were distributed into two groups: group 1 (stretching + ultrasound turned off) and group 2 (stretching + 2 w/cm² ultrasound). After 15 treatment sessions, an analysis of the absolute values and improvement percentages for collected variables was performed. A functional improvement was seen for both groups, with no difference between them. The analysis of the absolute values for pain intensity (at first, eighth, and last session) showed similarity between groups. The improvement percentage for 15 sessions did not present differences between both groups. That percentage was also calculated for two periods (before and after the eighth session). It was noted that the improvement percentage on all 15 sessions for group 2 (46.5 percent) was inferior to the percentage of the first eighth sessions for group 1 (54.6 percent). Thus, the high-power continuous ultrasound did not add value for function and pain; additionally, only specific stretching exercises were efficient in reducing more than 50 percent of the pain in chronic plantar fasciitis.


Assuntos
Humanos , Masculino , Feminino , Adulto , Fasciíte Plantar , Fasciíte Plantar , Terapia por Ultrassom , Estudos Prospectivos , Inquéritos e Questionários
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