Repositório Institucional - Unifesp :: Navegando por Palavras-chave "Mitochondria"

Navegando por Palavras-chave "Mitochondria"

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Altered mitochondrial function, calcium signaling, and catecholamine release in chromaffin cells of diabetic and SHR rats
(Elsevier Science Bv, 2017) Musial, Diego C. [UNIFESP]; Bomfim, Guilherme H. [UNIFESP]; Arranz-Tagarro, Juan A.; Mendez-Lopez, Iago; Miranda-Ferreira, Regiane [UNIFESP]; Jurkiewicz, Aron [UNIFESP]; Jurkiewicz, Neide H. [UNIFESP]; Garcia, Antonio G.; Padin, Juan F.
Comorbidity of diabetes and hypertension is frequent. Here, we have performed a comparative study in three animal models namely, normotensive Wistar Kyoto (WKY) rats, streptozotocin-induced diabetic rats (STZ), and spontaneously hypertensive rats (SHR). With respect WKY rats, we have found the following alterations in adrenal chromaffin cells from STZ and SHR rats: (1) diminished Ca2+ currents; (2) augmented [Ca2+](c) elevations and catecholamine release in cells stimulated with angiotensin II or high K+; (3) unchanged expression of angiotensin II receptors AT(1) and AT(2); (4) higher density of secretory vesicles at subplasmalemmal sites; (5) mitochondria with lower cristae density that were partially depolarized; and (6) lower whole cell ATP content. These alterations may have their origin in (i) an augmented capacity of the endoplasmic reticulum Ca2+ store likely due to (ii) impaired mitochondrial Ca2+ uptake; (iii) augmented high-[Ca2+](c) microdomains at subplasmalemmal sites secondary to augmented calcium-induce calcium release and to inositol tris-phosphate receptor mediated enhanced Ca2+ mobilization from the endoplasmic reticulum; and (iv) augmented vesicle pool. These alterations seem to be common to the two models of human hypertension here explored, STZ diabetic rats and SHR hypertensive rats.
Acesso aberto (Open Access)
Análise proteômica quantitativa de plasma seminal e sua associação com aspectos funcionais dos espermatozoides e com o nível de peroxidação lipídica no plasma seminal
(Universidade Federal de São Paulo (UNIFESP), 2014) Intasqui Lopes, Paula [UNIFESP]; Bertolla, Ricardo Pimenta [UNIFESP]; http://lattes.cnpq.br/8479803539567479; http://lattes.cnpq.br/5188240479960852; Universidade Federal de São Paulo (UNIFESP)
funcionais nos espermatozoides e o nivel seminal de peroxidacao lipidica. Metodo: Um estudo transversal foi realizado incluindo 156 pacientes normozoospermicos. Apos a coleta do semen por masturbacao, uma aliquota foi utilizada para a analise seminal e outra para a avaliacao da atividade mitocondrial, da integridade do acrossoma e da integridade do DNA dos espermatozoides. O volume remanescente de semen foi centrifugado e o plasma seminal sobrenadante foi utilizado para a avaliacao do nivel seminal de peroxidacao lipidica e para a analise proteomica. Posteriormente, os pacientes foram divididos em percentis (15%) para formacao dos grupos experimentais de cada estudo: Estudo 1 - alta (grupo controle) e baixa (grupo alterado) atividade mitocondrial dos espermatozoides, Estudo 2 - alta (grupo controle) e baixa (grupo alterado) integridade do acrossoma dos espermatozoides, Estudo 3 - baixa (grupo controle) e alta (grupo alterado) fragmentacao do DNA dos espermatozoides e Estudo 4 - baixo (grupo controle) e alto (grupo alterado) niveis seminais de peroxidacao lipidica. A analise proteomica foi realizada utilizando LCMS/MS. Os grupos foram comparados por meio de analise univariada (teste t de Student) e analise multivariada (PLS-DA e analise discriminante). As proteinas significantes foram posteriormente submetidas a analise de enriquecimento funcional. Resultados: Nos estudos 1, 2, 3 e 4 foram observadas 506, 493, 474 e 629 proteinas, respectivamente. As funcoes enriquecidas no estudo 1 foram detoxificacao de EROs e ligacao a NADP (controle) e atividade de oxidoredutase intramolecular, catabolismo de aminoglicanos, inibicao de endopeptidases, lisossomos e resposta imune de fase aguda (alterado). As principais funcoes enriquecidas no estudo 2 foram resposta imune (controle) e inibicao de fosfolipase, metabolismo do acido araquidonico, exocitose, resposta inflamatoria aguda, resposta ao peroxido de hidrogenio e transporte lisossomal (alterado). As principais funcoes enriquecidas no estudo 3 foram metabolismo de carboidratos, regulacao de lipoproteinas, regulacao negativa da apoptose, metabolismo de hormonios, atividade de metalopeptidases, ligacao ao NAD e lisossomos (controle) e biossintese de prostaglandinas e ligacao a acidos graxos (alterado). As principais funcoes enriquecidas no estudo 4 foram biossintese de acidos graxos insaturados, atividade de oxidantes e antioxidantes e resposta celular ao estresse termico (alterados). Nos estudos 1, 2, 3 e 4 foram sugeridos 8, 6, 8 e 7 biomarcadores seminais de atividade mitocondrial, integridade acrossoma, fragmentacao de DNA e peroxidacao lipidica, respectivamente. Conclusoes: O perfil proteomico do plasma seminal reflete alteracoes funcionais dos espermatozoides e o nivelseminal de peroxidacao lipidica e diversas funcoes pos-genomicas estao relacionadas as alteracoes estudadas. Proteinas relacionadas as alteracoes funcionais dos espermatozoides e ao nivel seminal de peroxidacao lipidica constituem potenciais biomarcadores seminais para cada alteracao
Somente Metadadados
Avaliação da sinalização intracelular mediada por agente desacoplador mitocondrial em modelo celular da doença de Alzheimer
(Universidade Federal de São Paulo (UNIFESP), 2021) Wachilewski, Patricia [UNIFESP]; Ureshino, Rodrigo Portes [UNIFESP]; Universidade Federal de São Paulo
Studies indicate that aging is the main risk factor associated with the onset of neurodegenerative diseases, such as Alzheimer's disease (AD). This is a progressive and incurable disease, and as it evolves to the severe dementia, the histopathological markers such as amyloid plaques and neurofibrillary tangles are more frequently observed. The pathophysiological alterations of AD and tauopathies (characterized by dementia and accumulation of tau protein) has not yet been fully elucidated, although it has been associated the neuronal cell death to the imbalance of molecules and essential ions for the maintenance of cellular homeostasis, such as the mitochondrial Ca 2+ accumulation. Thus, the objective of this study was to investigate the intracellular signaling induced by the uncoupler of the mitochondrial electron chain, DNP, in a cellular model of tauopathy, as well as its involvement in the process of cell death or protection. For this, SH-SY5Y control (CTR) cells were used, which conditionally overexpresses (by the Tet-On system) the tau protein WT (isoform 0N4R) and P301L (mutated), fused to eGFP. Our data shows that DNP does not alter cell viability at concentrations up to 100 µM and that it does not promote cell resistance to high metabolic and excitotoxic stress, but that it can promote a positive response against the oxidative stress. Moreover, our results show that treatment with DNP in SH-SY5Y control cells promotes the mobilization of intracellular Ca 2+ even after depletion of the endoplasmic reticulum (ER) and mitochondria stores, however the WT and P301L cells did not show significant changes of Ca 2+ mobilization after treatment of (10 µM and 100 µM) of DNP. Nevertheless, when submitted to treatment with the mitochondrial uncoupler FCCP, these cells presented a reduction in mitochondrial Ca 2+ mobilization. In addition, DNP demonstrated differential modulation of the mitochondrial membrane potential (∆Ψm) in cells that overexpress the tau WT and mutated P301L protein. These results suggest that DNP does not induce toxicity in cells that overexpress the tau protein in high concentrations and, despite not differentially modulating Ca 2+ signaling in the model of tauopathy, these cells already show impaired physiology and are more sensitive to the loss of ∆Ψm.
Acesso aberto (Open Access)
Baccharis dracunculifolia, the main source of green propolis, exhibits potent antioxidant activity and prevents oxidative mitochondrial damage
(Elsevier B.V., 2012-03-01) Guimaraes, Natalia S. S.; Mello, Joyce C.; Paiva, Juliana S.; Bueno, Paula C. P.; Berretta, Andresa A.; Torquato, Ricardo José Soares [UNIFESP]; Nantes, Iseli L.; Rodrigues, Tiago; Univ Mogi das Cruzes UMC; Univ Estadual Paulista UNESP; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP); Universidade Federal do ABC (UFABC)
Baccharis dracunculifolia DC (Asteraceae) is the main botanical source used by honeybees to produce Brazilian green propolis whose hepatoprotective properties have been already described. in this work we investigated the protective effects of the glycolic extract of B. dracunculifolia (GEBd) against oxidative stress in isolated rat liver mitochondria (RLM). the GEBd was prepared by fractionated percolation using propylene glycol as solvent. the total phenols and flavonoids, which are substances with recognized antioxidant action, were quantified in GEBd and the phytochemical analysis was carried out by HPLC. GEBd exhibited significant scavenger activity towards DPPH radicals and superoxide anions in a concentration-dependent manner, and also a Fe2+ chelating activity. GEBd decreased the basal H2O2 generation and the Fe2+- or t-BuOOH-induced ROS production in isolated mitochondria. Lipid oxidation of mitochondrial membranes, protein thiol groups and GSH oxidation were also prevented by GEBd. This shows that B. dracunculifolia exhibit potent antioxidant activity protecting liver mitochondria against oxidative damage and such action probably contribute to the antioxidant and hepatoprotective effects of green propolis. (C) 2011 Elsevier B.V. All rights reserved.
Somente Metadadados
Bcl-2 Modulates Endoplasmic Reticulum and Mitochondrial Calcium Stores in PC12 Cells
(Springer, 2012-02-01) Hirata, Hanako [UNIFESP]; Lopes, Guiomar S. [UNIFESP]; Jurkiewicz, Aron [UNIFESP]; Garcez-do-Carmo, Lucia [UNIFESP]; Smaili, Soraya Soubhi [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
Endoplasmic reticulum (ER) and mitochondria are intracellular organelles and their interactions are directly involved in different processes such as Ca2+ signaling in cell survival and death mechanisms. Bcl-2 is an anti-apoptotic protein intrinsically related to ER and mitochondria, modulating Ca2+ content in these organelles. We investigated the effects of Bcl-2 overexpression on ER and mitochondrial Ca2+ dynamics in PC12 cells. Bcl-2 overexpressing and control cells were loaded with Fura 2/AM and stimulated with different drugs. Results showed that in Bcl-2 cells, ACh induced a lower Ca2+ response compared to control. Ca2+ release induced by TG was decreased in Bcl-2 cells, however, it was greater in Caff induced Ca2+ rise. in addition, FCCP induced a higher Ca2+ release in Bcl-2 cells. These results suggest that Bcl-2 overexpression modulate the ER Ca2+ pools differently and the release of ER Ca2+ may increase mitochondrial Ca2+ accumulation. These alterations of intracellular Ca2+ stores are important mechanisms for the control of Ca2+ signaling.
Somente Metadadados
Bcl-X-L inhibits Bax-induced alterations in mitochondrial respiration and calcium release
(Elsevier B.V., 2008-09-12) Teles, Alessandra Vaz Fernandes Fiuza [UNIFESP]; Ureshino, Rodrigo Portes [UNIFESP]; Dorta, Daniel Junqueira [UNIFESP]; Lopes, Guiomar Silva [UNIFESP]; Hsu, Yi-Te; Smaili, Soraya Soubhi [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Med Univ S Carolina
Apoptosis is a natural cell elimination process involved in a number of physiological and pathological events. This process can be regulated by members of the Bcl-2 family. Bax, a pro-apoptotic member of this family, accelerates cell death, while the pro-survival member, Bcl-X-L, can antagonize the pro-apoptotic function of Bax to promote cell survival. in the present study, we have evaluated the effect of Bcl-X-L on Bax-induced alterations in mitochondrial. respiration and calcium release. We found that in primary cultured astrocytes, recombinant Bcl-X-L is able to antagonize Bax-induced decrease in mitochondrial respiration and increase in mitochondrial. calcium release. in addition, we found that Bcl-X-L can lower the calcium store in the endoplasmic reticulum, thus limiting potential calcium flux induced by apoptosis. This regulation of calcium flux by Bcl-X-L may represent an important mechanism by which this protein promotes cell survival. (c) 2008 Elsevier Ireland Ltd. All rights reserved.
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Biochemical studies with DNA polymerase beta and DNA polymerase beta-PAK of Trypanosoma cruzi suggest the involvement of these proteins in mitochondrial DNA maintenance
(Elsevier B.V., 2008-11-01) Lopes, Debora de Oliveira; Fonseca Schamber-Reis, Bruno Luiz; Regis-da-Silva, Carlos Gustavo; Rajao, Matheus Andrade; DaRocha, Wanderson Duarte; Macedo, Andrea Mara; Franco, Gloria Regina; Nardelli, Sheila Cristina [UNIFESP]; Schenkman, Sergio [UNIFESP]; Hoffmann, Jean-Sebastein; Cazaux, Christophe; Junho Pena, Sergio Danilo; Ribeiro Teixeira, Santuza Maria; Machado, Carlos Renato; Universidade Federal de Minas Gerais (UFMG); Universidade Federal de São Paulo (UNIFESP); CNRS
Mammalian DNA polymerase p is a nuclear enzyme involved in the base excision and single-stranded DNA break repair pathways. in trypanosomatids, this protein does not have a defined cellular localization, and its function is poorly understood. We characterized two Trypanosoma cruzi proteins homologous to mammalian DNA polymerase beta, TcPol beta and TcPol beta PAK, and showed that both enzymes localize to the parasite kinetoplast. in vitro assays with purified proteins showed that they have DNA polymerization and deoxyribose phosphate lyase activities. Optimal conditions for polymerization were different for each protein with respect to dNTP concentration and temperature, and TcPol beta PAK, in comparison to TcPol beta, conducted DNA synthesis over a much broader pH range. TcPol beta was unable to carry out mismatch extension or DNA synthesis across 8-oxodG lesions, and was able to discriminate between dNTP and ddNTP. These specific abilities of TcPol beta were not observed for TcPol beta PAK or other X family members, and are not due to a phenylalanine residue at position 395 in the C-terminal region of TcPol beta, as assessed by a site-directed mutagenesis experiment reversing this residue to a well conserved tyrosine. Our data suggest that both polymerases from T. cruzi could cooperate to maintain mitochondrial DNA integrity through their multiple roles in base excision repair, gap filling and translesion synthesis. (C) 2008 Elsevier B.V. All rights reserved.
Acesso aberto (Open Access)
Caracterização da disfunção mitocondrial no rim de ratos Zucker
(Universidade Federal de São Paulo (UNIFESP), 2016-04-05) Trindade, André Soares [UNIFESP]; Higa, Elisa Mieko Suemitsu [UNIFESP]; http://lattes.cnpq.br/8578252701813423; http://lattes.cnpq.br/963336381205462; Universidade Federal de São Paulo (UNIFESP)
Introduction: Obesity is characterized as an inflammatory condition associated to several chronic diseases. Besides promoting cardiovascular, hepatic and renal alterations, adipose tissue accumulation can generate an increased reninangiotensin-aldosterone system activity, increased oxidative stress and mitochondrial dysfunction. Aim: The aim of this study was to evaluate the kidney mitochondrial function of Zucker rats through cellular respiration, membrane potential, osmotic swelling, oxidative stress and antioxidant defense. Methods: Ten adult male rats were distributed into obese (Zucker rat strain with a mutation in the gene fa-/fa- and obese phenotype, N=5) and lean (lean Zucker rat strain, heterozygous fa+/fa- with eutrophic phenotype, N=5). In the kidney mitochondria we evaluated: the osmotic swelling with 3 different calcium concentrations (10, 25 or 50 µM Ca+2); the lipid peroxidation was measured by malondialdehyde (MDA) generation, oxidation of thiol groups, levels of reduced glutathione (GSH) and generation of reactive oxygen species by dichlorofluorescein diacetate (DCFDA). Results: In the analysis of kidney mitochondrial swelling, the obese rats showed lower values only at 10µM Ca+2 concentration vs lean (P<0.05). The kidney mitochondrial MDA (µM/mg protein) was also reduced in obese when compared to lean (P<0.05), even in the presence of the pro - oxidant tert-butylhydroperoxide (t-BOOH). Obese kidney mitochondrial sulphydryl (SH, nmol/mg protein) levels did not show statistical differences when compared to lean DCFDA (nmol/mg protein) levels increased only in the presence of t-BOOH , with no difference between the obese vs lean. Obese rats presented decreased levels of mitochondrial GSH (nmol/mg protein) vs lean rats (81±8 vs 133±18; P<0.05). Conclusion: In summary, our data showed that obese rats had a reduced kidney osmotic mitochondrial swelling if compared to lean rats, suggesting that the mitochondrial permeability could be altered in the obesity. The renal mitochondrial oxidative stress between obese and lean was different only in the evaluation of the MDA, being the antioxidant system reduced in the obese, comparatively to lean. So, in this study we observed that there are differences between the redox system of the obese and lean kidney mitochondria, which can be relevant when the mitochondria would be the target in the treatment of this pathology.
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Complex I spectrophotometric assay in cultured cells: Detailed analysis of key factors
(Elsevier B.V., 2013-04-01) Oliveira, Katia Klug [UNIFESP]; Kiyomoto, Beatriz Hitomi [UNIFESP]; Rodrigues, Andresa De Santi [UNIFESP]; Tengan, Celia Harumi [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
The diagnosis of mitochondrial encephalomyopathies caused by complex I (C-I) deficiency relies mainly on the spectrophotometric C-I assay. Considered difficult, this assay lacks reliability and has high nonspecific activity. We studied the key factors of this assay in cultured cells (cybrid and fibroblast): ubiquinone analogues, rotenone inhibition to determine specific activity, and mode of permeabilization of mitochondria] membranes. We showed that ubiquinone 1 allows a more stable and reliable assay, better results were obtained with rotenone inhibition done in the same assay, and mitochondria] permeability was improved just by freeze/thawing the sample prior to the assay. (C) 2012 Elsevier Inc. All rights reserved.
Acesso aberto (Open Access)
Deficiênciade coenzima Q10: caracterização clínica, bioquímica e molecular
(Universidade Federal de São Paulo (UNIFESP), 2018-11-29) Miyadahira, Juliana Harumi Arita [UNIFESP]; Barsottini, Orlando Graziani Povoas [UNIFESP]; Pedroso, José Luiz [UNIFESP]; Barros, Claudia Cristina Ferreiro de; http://lattes.cnpq.br/9366916338480574; http://lattes.cnpq.br/4482272200637616; http://lattes.cnpq.br/0768140730368272; http://lattes.cnpq.br/9094070637216442; Universidade Federal de São Paulo (UNIFESP)
Objective: to identify patients with suspected coenzyme Q10 deficiency (CoQ10) and make a clinical, biochemical and molecular characterization of these patients. Methods: twenty seven patients between 0 and 17 years old from Child Neurology and General Neurology and Ataxias clinics of Universidade Federal de São Paulo, with clinical suspicion of CoQ10 deficiency were selected and evaluated by our group of neurologists. They were submitted to preestablished complementary exams and classified according to one of the classic CoQ10 deficiency phenotypes. Biochemical studies (CoQ10 content, mitochondrial complexes, oxidative stress measurements, citrate synthase dosage, glutathione peroxidase activity and mitochondrial DNA quantification) were performed on skin fibroblasts. Total CoQ10 skin fibroblasts was measured by HPLC / ECD. Mitochondrial complexes, citrate synthase activities and glutathione peroxidase were measured by spectrophotometry. Oxidative stress was measured by cell marking of superoxide anions with MitoSOX kit. Quantification of mitochondrial DNA was obtained by normalizing its quantity by the single copy of the B2M gene. Molecular analyzes by exome sequencing were performed in those with low CoQ10 levels compared to controls or with suggestive biochemical profile. Statistical analysis was applied to the biochemical tests using oneway ANOVA followed by Bonferroni adjustment for multiple comparisons, considering p <0.05. Results: five out of twenty seven patients had CoQ10 deficiency. Patients with CoQ10 deficiency presented variable activities of mitochondrial complexes. Citrate synthase activity was increased to 3 of them. The generation of superoxide anions was increased to 2 patients suggesting mitochondrial dysfunction. Molecular analysis could identify secondary CoQ10 deficiencies.
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Deleções do DNA mitocondrial no envelhecimento: efeito da disfunção na fosforilação oxidativa
(Universidade Federal de São Paulo (UNIFESP), 1997) Tengan, Celia Harumi [UNIFESP]; Gabbai, Alberto Alain [UNIFESP]
Acesso aberto (Open Access)
O efeito do tratamento com carnosina durante o processamento seminal de amotras humanas por gradiente de densidade descontínuo
(Universidade Federal de São Paulo (UNIFESP), 2018-02-27) Adami, Luana Nayara Gallego [UNIFESP]; Nichi, Marcilio; http://lattes.cnpq.br/7054360633543023; Universidade Federal de São Paulo (UNIFESP)
Introdução: A infertilidade masculina pode ser causada pelo estresse oxidativo seminal que leva prejuízos aos espermatozoides. Entretanto, o plasma seminal possui mecanismos antioxidantes para tentar neutralizar esses danos celulares. Por outro lado, as biotécnicas utilizadas durante o processamento seminal tendem a diminuir essa proteção antioxidante aumentando os danos oxidativos ao gameta. Na tentativa de minimizar os danos, antioxidantes exógenos são suplementados nos sistemas in vitro. A carnosina, reportada por sua potente função antioxidante, tem capacidade de reagir com produtos responsáveis por provocar danos celulares. Dessa forma suplementar carnosina nos meios de processamento seminal levaria a uma melhora na qualidade funcional dos espermatozoides. Objetivo: Avaliar o efeito de diferentes concentrações da carnosina no processamento das amostras seminais. Método: As amostras seminais (n=34) foram divididas em 3 grupos e seguiram para o processamento seminal: grupo controle sem suplementação com a carnosina (0) recebeu as camadas de gradiente de densidade descontínua – Percoll (80% e 40%) e a amostra; o grupo 20 mM, por sua vez, teve as camadas de Percoll suplementadas com 20 mM de carnosina; finalmente, o grupo 50mM teve as camadas de Percoll suplementadas com 50 mM de carnosina. As amostras passaram pelo processo de gradiente de densidade descontínuo por 20 minutos a 600xG e foram lavadas com meio de cultura fluido tubário humano (HTF) por 10 minutos a 600xG. Após o processamento, os espermatozoides foram avaliados quanto ao potencial de membrana mitocondrial, à produção de ânion superóxido intracelular, à fragmentação de DNA espermático, à integridade acrossômica, à atividade mitocondrial, à integridade de membrana plasmática e à motilidade espermática. Para analisar a normalidade e esfericidade dos dados, utilizamos os testes de Kolmogorov-Smirnov e de Mauchly respectivamente, e então o General Linear Model (GLM) com teste post-hoc de Sidak. Para as variáveis não normais foi utilizado o teste não paramétrico de Friedman com post-hoc de Games-Howell, considerando α = 5% e utilizando o programa SPSS21. Resultados: A suplementação com a carnosina na concentração de 50 mM levou à melhora da atividade mitocondrial dos espermatozoides quando comparado ao grupo controle. Para variáveis como % de espermatozoides móveis e % de espermatozoides progressivos, velocidade média de percurso, retilínea e curvilínea, e linearidade dos espermatozoides houve uma melhora nos índices após o gradiente de densidade descontínuo, entretanto as concentrações de carnosina não foram efetivas. Já para a frequência de batimento dos flagelos a presença de carnosina em ambas concentrações elevou as frequências quando comparadas à amostra antes do gradiente de densidade descontínuo. Conclusão: A suplementação da carnosina nas amostras seminais humanas pode apresentar efeito benéfico para a atividade mitocondrial espermática e a frequência de batimento cruzado, amenizando os possíveis danos provocados pelo processamento seminal.
Acesso aberto (Open Access)
Efeito do treinamento físico de natação nos ratos espontaneamente hipertensos (SHR) antes, durante e após o desenvolvimento da Hipertensão Arterial
(Universidade Federal de São Paulo (UNIFESP), 2019-06-27) Garcia, Maureen Gabriela Pena [UNIFESP]; Landman, Maria Teresa Riggio De Lima [UNIFESP]; Ferreira, Regiane Miranda; http://lattes.cnpq.br/2114763192130851; http://lattes.cnpq.br/8687378770717503; http://lattes.cnpq.br/2575241678795406; Universidade Federal de São Paulo (UNIFESP)
Hypertension is a disease of high prevalence and mortality in the world. Changes in the sympathetic nervous system (SNS) and cellular calcium homeostasis are present in hypertension. In addition, a link was also established between increased SNS activity and inflammation in the pathophysiology of hypertension. The physical training (PT) originates a series of physiological adaptations that influence the cardiovascular system; this physical training is used in hypertensive patients, as non-medicated treatment for the control of blood pressure (BP). The aim of the present study was to study the effect of swimming on sympathetic neurotransmission and cellular calcium homeostasis in chromaffin cells of the adrenal gland (CCA), vas deferens (VD), retroperitoneal adipose tissue and concentration in serum of C reactive protein (CRP) in spontaneously hypertensive rats (SHR) before, during and after development of hypertension. Using normotensive animals (NWR) and SHR aged 8-12-20 weeks divided into three groups: sedentary NWR (NWR-Sed), sedentary SHR (SHR-Sed) and trained SHR (SHR-Tre). We evaluated the effect of swimming in: 1) arterial pressure and heart mass, 2) secretion of catecholamines by CCA and VD. 3) participation of calcium channel dependent voltage (CCDV), in pharmacological and neurogenic contraction and cellular calcium homeostasis, 4) concentrations of calcium present in the intracellular stores of the endo/sarcoplasmic reticulum (RE/RS) and mitochondria (MIT), VD and CCA, 5) retroperitoneal fat amount, 6) serum concentration of C reactive protein (CRP). Compared to SHR-Sed, SHR-Tre: 1) prevented BP increase, and increased heart mass. 2) decreased basal [Ca2+]i and after stimulation with ACh in CCA, 3) decreased catecholamine secretion when CCA were stimulated with Bay K-8644 with CRT and CCCP. 4) reduced twitch neurogenic contraction in the presence of Bay K-8644, CRT and CCCP. 5) reduced the responses of α1 and P2X1 in DD. 6) decreased retroperitoneal fat, and 7) reduced the serum concentration of CRP in all groups of trained animals. Based on the above results we can conclude that the training was able to attenuate the increase in blood pressure and remodeling of the heart mass in SHR-Tre animals. In addition, it produced a reduction of the sympathetic nerve activity evidenced by the reduction of [Ca2+]i, which may have led to a decrease in catecholamine secretion and a decrease in neurogenic contractions, reduced the amount of retroperitoneal fat and CRP concentrations. These data suggest the effectiveness of physical training in preventing the establishment of arterial hypertension as well as its underlying effects in our animal model and reinforce the indication of physical activity as a participant in non-drug treatment of arterial hypertension.
Somente Metadadados
Endoplasmic Reticulum Calcium Release Engages Bax Translocation in Cortical Astrocytes
(Springer, 2011-05-01) Morales, A. P.; Carvalho, A. C. P.; Monteforte, P. T.; Hirata, H.; Han, S. W. [UNIFESP]; Hsu, Y. -T.; Smaili, Soraya Soubhi [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Med Univ S Carolina
Apoptosis is a highly complex form of cell death that can be triggered by alterations in Ca(2+) homeostasis. Members of the Bcl-2 family may regulate apoptosis and modulate Ca(2+) distribution within intracellular compartments. Bax, a proapoptotic member of the family, is constitutively expressed and soluble in the cytosol and, under apoptotic induction, translocates to mitochondrial membranes. However, it is not clear if the intracellular Ca(2+) stores and selective Ca(2+) releases can modulate or control Bax translocation. the aim of this study was to investigate the relation of intracellular Ca(2+) stores with Bax translocation in rat cortical astrocytes. Results show that the classical apoptotic inducer, staurosporine, caused high elevations of cytosolic Ca(2+) that precede Bax translocation. On the other hand, agents that mobilize Ca(2+) from endoplasmic reticulum such as noradrenaline or thapsigargin, induced Bax translocation, while mitochondrial Ca(2+) release evoked by carbonyl cyanide-p-(trifluoromethoxyphenyl) hydrazone was not able to cause Bax punctation. in addition, microinjection of inositol 1,4,5- trisphosphate induced Bax translocation. Taken together, our results show that in Bax overexpressing cortical astrocytes, endoplasmic reticulum-Ca(2+) release may induce Bax transactivation and specifically control apoptosis.
Acesso aberto (Open Access)
Esclerose Lateral Amiotrófica e as diversidades das distribuições das variantes (SNPs, indel) das enzimas de cadeia respiratória relacionadas à neuroproteção/neurodegeneração nas populações dos haplogrupos mitocondriais: uma análise de 1000 GENOME PROJECT
(Universidade Federal de São Paulo (UNIFESP), 2019-09-26) Mehrpour, Sheida [UNIFESP]; Oliveira, Acary Souza Bulle [UNIFESP]; Briones, Marcelo [UNIFESP]; http://lattes.cnpq.br/0018992452321910; http://lattes.cnpq.br/3911841387107665; http://lattes.cnpq.br/3656019291521709; Universidade Federal de São Paulo (UNIFESP)
Amyotrophic Lateral Sclerosis (ALS) is a disease characterized by the degeneration of motor neurons in the brain and spinal cord, causing progressive, irreversible and incapacitating motor paralysis. Regarding the etiology of ALS, several factors have been included: acquired nuclear enzyme abnormalities, glutamate toxicity, oxidative stress, defective axonal transport, neurofilament abnormalities, genetic factors, viral infections, and mitochondrial dysfunction. There is strong evidence that mitochondria are one of the main targets of impairment in motor neurons, with changes in the electron transport complexes of the mitochondrial chain, affecting the final production of ATP. The impaired function of mitochondrial respiratory complexes has been linked to the quantitative and / or qualitative defects of these components. Previous studies have shown that some of the mitochondrial respiratory chain enzymes, including Riboflavin kinase (RFK), flavin adenine dinucleotide synthetase (FAD), Succinate dehydrogenase B subunit (SDHB), and Cytochrome C1 (CYC1) are associated with several mechanisms of neuroprotection and dysfunctions of these enzymes are related to neurodegeneration. In addition, there is evidence that these enzymes having quanitative defects are compromised in ALS patients. Considering that several studies have demonstrated an intimate relationship between mitochondria and ALS, we have proposed to rigorously analyze the information collected at the ENSEMBLE GENOME BROWSER 91 website (updated site of 1000 GENOME PROJECT, updated in December 2017), with variant description of the genes of these enzymes including RFK, FAD, SDHB, and CYC1, of the 2.540 individuals from 26 different populations of the five places of the world belong to the different mitochondrial haplogroups, identifying the distributions of the variants of these enzymes in the different populations of the mitochondria haplogroups. The study is based on the Hardy-Weinberg equilibrium calculation. Deviation of the Hardy-Weinberg equilibrium in the control group may reflect an expectation about the development of a disease or a clinical disorder or susceptibility to a disease. We were able to identify the diversity of the distributions of the mitochondrial respiratory chain enzymes variants including RFK, FAD, SDHB, and CYC1 in mitochondrial haplogroup populations by deviation of the equilibrium of certain variants of these enzymes, confirming the susceptibility of different haplogroup populations about ALS disease and through this information we can apply prognostic, diagnostic and therapeutic antioxidant strategies for ALS patients. This finding reflects how we conduct clinical trials in the individualized therapeutic determination of each ALS patient depending on the patient haologroup and the compromised enzyme.
Somente Metadadados
Estudo da sinalização da morte celular e de alterações comportamentais em modelos animais da doença de Huntington
(Universidade Federal de São Paulo (UNIFESP), 2004) Rosenstock, Tatiana Rosado [UNIFESP]; Smaili, Soraya Soubhi [UNIFESP]
Introdução: Alterações na homeostase do Ca2+ podem levar a desordens neurodegenerativas como a Doença de Huntington (DH). A DH e caracterizada por declínio cognitivo, distúrbio psíquico e movimentos motores involuntários. Vários mecanismos, além do genético, tem sido sugeridos como responsáveis: excitotoxicidade, estresse oxidativo e disfunção mitocondrial, que envolve transição de permeabilidade mitocondrial (TPM), colapso do potencial de membrana mitocondrial (,NIY,) e liberação do cálcio mitocondrial (Ca2+m). Juntos, esses fatores podem levar a apoptose. Objetivo: O objetivo deste projeto foi investigar os mecanismos celulares envolvendo o transporte de Ca 2+ relacionados com a disfunção mitocondrial e a morte celular, bem como a relação destes mecanismos com os desvios comportamentais, em dois modelos animais da DH: a) animais tratados com o ácido 3-nitropropionico (3NP), inibidor da enzima succinato desidrogenase (SDH), componente da cadeia respiratória mitocondrial; b) animais transgênicos da linhagem R6/1. Conclusões: As alterações comportamentais induzidas pelo 3NP parecem estar relacionadas com a inibição mitocondrial e com o aumento do estresse oxidativo, diminuição ∆m, liberação do Ca 2'm e morte celular. As fatias cerebrais dos animais transgênicos apresentaram alterações na homeostase de Ca 2+ que podem estar relacionadas a degeneração observada na DH. Por outro lado, os transgênicos não apresentaram diferença quanto a SDH. Esse resultado pode ser devido a idade dos animais, e não descarta a possibilidade de tais diferenças aparecerem em uma fase tardia da DH. Além disso, nossos resultados mostraram que os animais transgênicos possuem uma tendência a menor atividade geral, maior movimentos mandibulares e maior alteração de equilíbrio e coordenação motora, bem como um déficit significante de memória
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Estudo do papel da proteína p53 no corpo estriado de ratos jovens e senescentes
(Universidade Federal de São Paulo (UNIFESP), 2012) Ureshino, Rodrigo Portes [UNIFESP]; Smaili, Soraya Soubhi [UNIFESP]
O envelhecimento e um processo multi-fatorial associado a deficits funcionais, sendo que o cerebro e um dos orgaos com maior susceptibilidade a doencas cronico-degenerativas. O entendimento dos mecanismos moleculares do envelhecimento cerebral e importante para a busca de novas estrategias para se evitar ou tratar de maneira mais eficaz as doencas neurodegenerativas, como a doenca de Parkinson, que acomete a via nigroestriatal. Dados anteriores do nosso laboratorio demonstraram que, no corpo estriado de animais senescentes, ha um aumento do numero de celulas apoptoticas, associado ao aumento na expressao genica da proteina pro-apoptotica Bax. A expressao de bax pode ser ativada pelo fator de transcricao p53 apos um dano irreversivel no DNA, o que amplifica o sinal de apoptose pela via intrinseca. Alem disso, ha evidencias de que, no envelhecimento do sistema nervoso central, ocorrem alteracoes na homeostase do calcio (Ca2+) e na sinalizacao glutamatergica, o que pode contribuir para a ocorrencia da morte celular por apoptose. No presente trabalho foi proposto o estudo de alteracoes moleculares consequentes do processo de envelhecimento em fatias de cerebro de ratos contendo o corpo estriado. O objetivo do trabalho foi estudar, em fatias cerebrais cotendo o corpo estriado, alteracoes subcelulares decorrentes da modulacao da proteina p53, considerando a sinalizacao de Ca2+, fisiologia mitocondrial, expressao de proteinas apoptoticas e viabilidade do tecido, em condicoes de estimulacao fisiologica e excitotoxica. Inicialmente foi feito um estudo molecular em corpo estriado isolado e em fatias cerebrais. Posteriormente, realizou-se o estudo das alteracoes subcelulares provocadas pela ativacao (pela exposicao a luz UV) ou inibicao (com o uso de pifithrin a e pifithrin m) de p53, na ausencia e presenca de estimulacao. Os dados mostraram que a exposicao a luz UV promove uma elevacao do Ca2+citosolico em de neuronios de projecao do corpo estriado de animais senescentes, quando comparados aos jovens, apos um estimulo fisiologico. Alem disso, constatou-se que essa irradiacao do tecido interfere com o tamponamento de Ca2+ mitocondrial, promovendo uma diminuicao de Ca2+ mitocondrial no grupo jovem e aumento nos animais senescentes, em relacao aos controles dos respectivos grupos. A proteina p53 pode modular indiretamente a respiracao mitocondrial, dado que esta e fundamental para a resistencia do tecido a um insulto excitotoxico prolongado. Portanto, os achados deste trabalho indicam que a modulacao das funcoes transcricionais e nao transcricionais da proteina p53 podem estar relacionadas a vulnerabilidade do corpo estriado de animais senescentes frente a um insulto excitotoxico, podendo assim contribuir para a diminuicao da funcao observada no processo de envelhecimento
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Estudo Dos Efeitos Da Suplementação De L-Arginina Sobre A Função E Conteúdo Mitocondrial Em Cultura De Células Com Deficiência Mitocondrial
(Universidade Federal de São Paulo (UNIFESP), 2018-12-19) Barros, Camila Dantas Dos Santos [UNIFESP]; Tengan, Celia Harumi [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
In Recent Years L-Arginine (L-Arg) Has Been Suggested As A Therapeutic Option For Some Diseases With Mitochondrial Deficiencies, Including Mitochondrial Encephalomyopathy, Lactic Acidosis And Stroke-Like Syndrome (Melas). Initial Studies Have Shown That L-Arg Supplementation Led To Improvement In Symptoms In Patients With Melas, Specially Stroke-Like Episodes. This Clinical Improvement Has Been Atributed To The Fact That L-Arg Is An Nitric Oxide (No") Precursor, L-Arg Is Able To Restore No" Levels In Blood Vessels, Improving Cerebral Blood Flow. However, The Mechanism By Which This Occurs Is Unclear. In Addition, No" Is Also Involved In Mitochondrial Biogenesis, Regulation Of The Mitochondrial Respiratory Chain And Nitro- Oxidative Stress. Our Aim Was To Verify The Effects Of L-Arg Supplementation On Mitochondrial Mass And Function In Cells With Miochondrial Deficiency. We Used Cybrid Cells Derived From Osteosarcoma Containing The M.3243a>G Mutation And Cells With No Mitochondrial Deficiency(143b), As Control
Acesso aberto (Open Access)
Estudo dos efeitos de Dicer sobre a função mitocondrial, o metabolismo e o envelhecimento em nematoides C. elegans
(Universidade Federal de São Paulo (UNIFESP), 2017-08-31) Silva, Silas Pinto da [UNIFESP]; Mori, Marcelo Alves da Silva [UNIFESP]; http://lattes.cnpq.br/3425809117024031; http://lattes.cnpq.br/3855491599849881; Universidade Federal de São Paulo (UNIFESP)
Introdução e objetivos: O envelhecimento é uma das mais significativas tendências do século XXI e tem preocupado governos do mundo todo por sua implicação em inúmeros setores da sociedade. Entender como o tempo de vida é controlado é necessário para que estratégias sejam propostas com a finalidade de , garantir um envelhecimento saudável para a população. Sabe-se que o envelhecimento é uma sucessão de eventos biológicos que, como tantos outros, está sob controle biológico. Dentre outros, grupos de genes que controlam vias nutricionais e metabólicas mostram-se cada vez mais importantes no contexto do envelhecimento. Com o intuito de melhor entender o sistema descrito acima, procuramos respostas no estudo de um dos grandes efetores do controle da expressão gênica, os miRNAs e de Dicer, enzima chave no processamento dos mesmo, com o fim de avaliar qual o papel desta via para a regulação do metabolismo e do envelhecimento. Métodos: Foram-avaliados o tempo de vida, o declínio da função muscular associado à idade, a resistência ao estresse oxidativo e térmico, o tempo de desenvolvimento, a taxa de bombeamento da faringe, a espressão global de miRNAs, a fertilidade, a respiração basal, o conteúdo lipídico, a quantificação de ATP e a quantidade de mitocôndrias em vermes mutantes ou selvagem tratados com estressores ou fármacos que promovem a saúde dos vermes. Resultados: Nossos dados sugerem que o silenciamento de Dicer, enzima chave é extremante deletério em nematoides C. elegans levando à diminuição do tempo de vida de vermes selvagens e retardando seu desenvolvimento. Adicionalmente, esta intervenção promove diminuição da respiração, causa estresse oxidativo e inibe os efeitos benéficos de mutações ou intervenções que dependem da função mitocondrial para estender o tempo de vida. Além disso, o enoxacino, um fármaco que ativa o processamento de miRNAs age de maneira contrária, melhorando a saúde dos vermes de maneira dependente do miRNA mir-34.
Acesso aberto (Open Access)
Estudo dos mecanismos celulares e moleculares envolvidos no processo neurodegenerativo da Doença de Huntington
(Universidade Federal de São Paulo (UNIFESP), 2008-05-28) Rosenstock, Tatiana Rosado [UNIFESP]; Smaili, Soraya Soubhi [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
Introdução: Alterações no tamponamento do cálcio citosólico (Ca+2 c) podem levar à desordens neurodegenerativas como a Doença de Huntington (DH). Vários mecanismos estão relacionados esses processos tais como a excitotoxicidade, o estresse oxidativo e as interações da proteína huntintina mutante (mhtt) com outras proteínas como a transglutaminase 2 (TG2). Essas alterações podem estar relacionadas com a ativação de mecanismos de morte celular ou autofagia. Objetivo: O objetivo deste projeto foi investigar os mecanismos celulares e moleculares envolvidos no processo de neurodegeneração da DH tais como alterações dos níveis de Ca+2 c relacionados com o transporte de Ca+2 mitocondrial (Ca+2 m) e reticular (Ca+2 RE), disfunção mitocondrial e morte celular, em três modelos experimentais: a) animais transgênicos da linhagem R6/1; b) linfoblastos provenientes de pacientes com DH; c) células MEFs (fibroblastos) normais e knock-outs para a TG2, na presença ou ausência da mhtt. Resultados e Conclusões: Nos camundongos transgênicos R6/1 houve um aumento significante do Ca+2 c em relação aos controles aos 9 meses de idade. Essa alteração parece ser devido a um aumento da liberação do Ca+2 m, do estresse oxidativo, do potencial de membrana mitocondrial (DYm) e do consumo de oxigênio. Os transgênicos não apresentaram diferença quanto à SDH, muito embora haja um aumento desta com o envelhecimento. Além disso, os linfoblastos de pacientes com DH apresentaram alterações do Ca+2 m e do Ca+2 RE, bem como um aumento na taxa de células autofágicas. Por outro lado, nas células de fibroblastos de camundongos embrionários (MEFs), a presença de mhtt parece não afetar a homeostase celular de Ca2+. A ausência da TG2 nestas células, influenciou não somente os níveis de Ca2+ c como também protegeu as células contra autofagia, mesmo na presença de mhtt.

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