Envolvimento do NF-kB e PPAR-gama na resposta inflamatória e metabólica em monócitos de pessoas com diferentes níveis de condicionamento físico na resposta ao exercício agudo de diferentes intensidades
Data
2018-12-12
Autores
Antunes, Barbara de Moura Mello [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O estilo de vida sedentário associa-se com alterações no perfil lipídico, inflamação crônica de baixo grau e aumento do tecido adiposo. Frente a essa questão, levantamos a hipótese de que alterações inflamatórias e metabólicas favorecem a instalação e progressão de diversas alterações metabólicas, e estão diretamente envolvidas com aptidão cardiorrespiratória mensurada pelo consumo de oxigênio pico (baixo ou alto VO2pico). Sendo assim, o presente estudo buscou responder duas questões centrais divididas em duas etapas: ESTUDO I – avaliação das respostas metabólicas e inflamatórias periférica durante diferentes intensidades de esforço de acordo com o nível de condicionamento físico dos sujeitos; ESTUDO II – avaliação da resposta metabólica e inflamatória celular de acordo com o nível de condicionamento físico. Para o ESTUDO I foram recrutados 28 sujeitos saudáveis do sexo masculino (idade: 28,8±8,6 anos; peso: 75,8±9,9 kg; VO2pico: 50,5±8,8 mL.kg-1.min-1) que realizaram por 60 minutos ou até a exaustão voluntária três protocolos de exercício agudo em baixa (<60% VO2pico), moderada (60-75% VO2pico) e alta intensidade (>90% VO2pico). Em todas as sessões foram coletadas amostras de sangue pré, imediatamente após e 60 minutos após o término da sessão para a determinação das concentrações de citocinas (TNF-α, IL-6, IL-10, IFN-γ, PAI-1, adiponectina), hormônios (leptina e insulina) e parâmetros lipídicos (colesterol total, triacilglicerol, HDL-c e ácidos graxos livres). No ESTUDO I, observou-se que a sessão de esforço propiciou significantes modulações sobre TNF-α, IL-6, razão IL-6/IL-10, lactato e ácidos graxos, principalmente em alta intensidade; além de significantes correlações entre a produção de IL-10 durante o exercício com o nível de condicionamento físico, no sangue periférico e estimulado. Interessantemente, o exercício de alta intensidade foi capaz de aumentar as concentrações sistêmicas de PAI-1 imediatamente após a sessão. Parao ESTUDO II foram recrutados 22 sujeitos (idade: 25,8±5,7 anos; peso: 76,5±14,4 kg; VO2pico: 47,8±12,3 mL.kg-1.min-1) para avaliar a produção de citocinas e expressão gênica de marcadores associados com a atividade do PPAR-γ e NF-κB em monócitos tratados por 24h sobre a presença de lipopolissacarideo (ativador da via inflamatória TLR-4/NF-kB), rosiglitazona e GW9662 (agonista e antagonista de PPAR- γ, respectivamente). Observou-se a nível molecular que maiores concentrações de IL-6 são produzidas por monócitos de sujeitos de alto VO2pico enquanto maiores concentrações de IL-10 são produzidas em sujeitos de baixo VO2pico. Quando avaliada a expressão gênica de proteínas das vias de sinalização do PPAR-γ e NF-κB observou-se maior expressão de AMPK, TLR-4, PGC-1 e PPAR-γ no grupo de alto VO2pico. Sendo assim, conclui-se que o exercício físico em intensidades altas impõe importantes alterações metabólicas que favorecem a instalação do quadro antiinflamatório, entretanto tais adaptações periféricas são dependentes do nível de condicionamento físico, dado que indivíduos de maior aptidão cardiorrespiratória apresentam maior expressão de proteínas e receptores celulares que modulam positivamente a ativação do PPAR-γ e inibem a via inflamatória do NF-kB. Desta forma, indivíduos de alto condicionamento físico apresentam adaptações benéficas nos mecanismos celulares e moleculares que refletem nas respostas metabólicas e inflamatórias periféricas frente à prática de exercício físico.
Sedentary lifestyle is associated with changes on lipid profile, low-grade chronic inflammation and increased adipose tissue. In this line, we hypothesized that inflammatory and metabolic alterations favor the installation and progression of several metabolic disorders, and are directly involved with cardiorespiratory fitness (VO2peak uptake). Thus, the present study sought to answer two central questions divided into two steps: EXPERIMENT I - evaluation of the metabolic and inflammatory peripheral responses during different exercise intensities according to cardiorespiratory fitness; EXPERIMENT II - evaluation of cellular metabolic and inflammatory response according to the cardiorespiratory fitness. For EXPERIMENT I, 28 healthy male subjects were recruited (age: 28.8 ± 8.6 years, weight: 75.8 ± 9.9 kg, VO2peak: 50.5 ± 8.8 mL.kg-1.min-1) and performed for 60 minutes or until voluntary exhaustion three acute exercise protocols at low (<60% VO2peak), moderate (60-75% VO2peak) and high (> 90% VO2peak) intensities. In all sessions, blood sample was collected pre, immediately after exercise and 60 minutes after the end of each session to determine cytokine concentrations (TNF-α, IL-6, IL-10, IFN-γ, PAI-1, adiponectin), hormones (leptin and insulin) and lipid parameters (total cholesterol, triacylglycerol, HDL-c, and free fatty acids). In EXPERIMENT I, was observed that acute session provided significant modulations on TNF-α, IL-6, IL-6/IL-10 ratio, lactate and fatty free acids, mainly at high intensity; in addition, significant correlations was verified between IL-10 release during exercise and cardiorespiratory fitness in peripheral and stimulated-blood. Interestingly, high-intensity exercise was able to increase systemic concentrations of PAI-1 immediately after the session. For EXPERIMENT II, 22 subjects were recruited (age: 25.8 ± 5.7 years, weight: 76.5 ± 14.4 kg, VO2peak: 47.8 ± 12.3 mL.kg-1.min-1) to evaluate cytokine production and gene expression of markers associated with activation and/or inhibition of PPAR-γ and NF-κB in monocytes treated for 24h on the presence or absence of lipopolysaccharide (pro-inflammatory pathway activator by TLR-4/NF-κB), rosiglitazone and GW9662 (PPAR-γ agonist and antagonist, respectivetly). It was observed that higher concentrations of IL-6 are produced by monocytes of subjects with high VO2peak while higher concentrations of IL-10 are produced in subjects with low VO2peak. When the protein expression of PPAR-γ and NF-κB signaling pathways was evaluated, higher expression of AMPK, TLR-4, PGC-1 and PPAR-γ was observed in the high VO2peak group. Therefore, it is concluded that physical exercise at higher intensities imposes important metabolic changes that favor the installation of an antiinflammatory profile, however these peripheral adaptations are fitness-dependent, given that individuals with greater cardiorespiratory fitness have higher expression of proteins and cellular receptors that positively modulate the PPAR-γ activation and inhibit the NF-κB inflammatory pathway. In this sense, individuals with high physical fitness condition present beneficial adaptations in the cellular and molecular mechanisms that reflect in metabolic and inflammatory peripheral responses mediated by physical exercise practice.
Sedentary lifestyle is associated with changes on lipid profile, low-grade chronic inflammation and increased adipose tissue. In this line, we hypothesized that inflammatory and metabolic alterations favor the installation and progression of several metabolic disorders, and are directly involved with cardiorespiratory fitness (VO2peak uptake). Thus, the present study sought to answer two central questions divided into two steps: EXPERIMENT I - evaluation of the metabolic and inflammatory peripheral responses during different exercise intensities according to cardiorespiratory fitness; EXPERIMENT II - evaluation of cellular metabolic and inflammatory response according to the cardiorespiratory fitness. For EXPERIMENT I, 28 healthy male subjects were recruited (age: 28.8 ± 8.6 years, weight: 75.8 ± 9.9 kg, VO2peak: 50.5 ± 8.8 mL.kg-1.min-1) and performed for 60 minutes or until voluntary exhaustion three acute exercise protocols at low (<60% VO2peak), moderate (60-75% VO2peak) and high (> 90% VO2peak) intensities. In all sessions, blood sample was collected pre, immediately after exercise and 60 minutes after the end of each session to determine cytokine concentrations (TNF-α, IL-6, IL-10, IFN-γ, PAI-1, adiponectin), hormones (leptin and insulin) and lipid parameters (total cholesterol, triacylglycerol, HDL-c, and free fatty acids). In EXPERIMENT I, was observed that acute session provided significant modulations on TNF-α, IL-6, IL-6/IL-10 ratio, lactate and fatty free acids, mainly at high intensity; in addition, significant correlations was verified between IL-10 release during exercise and cardiorespiratory fitness in peripheral and stimulated-blood. Interestingly, high-intensity exercise was able to increase systemic concentrations of PAI-1 immediately after the session. For EXPERIMENT II, 22 subjects were recruited (age: 25.8 ± 5.7 years, weight: 76.5 ± 14.4 kg, VO2peak: 47.8 ± 12.3 mL.kg-1.min-1) to evaluate cytokine production and gene expression of markers associated with activation and/or inhibition of PPAR-γ and NF-κB in monocytes treated for 24h on the presence or absence of lipopolysaccharide (pro-inflammatory pathway activator by TLR-4/NF-κB), rosiglitazone and GW9662 (PPAR-γ agonist and antagonist, respectivetly). It was observed that higher concentrations of IL-6 are produced by monocytes of subjects with high VO2peak while higher concentrations of IL-10 are produced in subjects with low VO2peak. When the protein expression of PPAR-γ and NF-κB signaling pathways was evaluated, higher expression of AMPK, TLR-4, PGC-1 and PPAR-γ was observed in the high VO2peak group. Therefore, it is concluded that physical exercise at higher intensities imposes important metabolic changes that favor the installation of an antiinflammatory profile, however these peripheral adaptations are fitness-dependent, given that individuals with greater cardiorespiratory fitness have higher expression of proteins and cellular receptors that positively modulate the PPAR-γ activation and inhibit the NF-κB inflammatory pathway. In this sense, individuals with high physical fitness condition present beneficial adaptations in the cellular and molecular mechanisms that reflect in metabolic and inflammatory peripheral responses mediated by physical exercise practice.
Descrição
Palavras-chave
Sedentarismo, Exercício físico, Metabolismo, Inflamação, Fatores de transcrição, Sedentary lifestyle, Physical exercise, Metabolism, Inflammation, Transcription factors