Serum Levels of BDNF in Cardiovascular Protection and in Response to Exercise. / Níveis Séricos do BDNF na Proteção Cardiovascular e em Resposta ao Exercício.

Cardiovascular disease (CVD) is currently the leading cause of death in Brazil and worldwide. In 2016, CVD accounted for more than 17 million deaths, representing 31% of all deaths globally. Molecular and genetic mechanisms may be involved in vascular protection and should be considered in new therapeutic approaches. In this sense, recent studies have reported that brain-derived neurotrophic factor (BDNF) is reduced in individuals predisposed to develop CVD, and that aerobic physical training increases the amounts of circulating BDNF. BDNF is a neurotrophin found at high concentrations in the hippocampus and cerebral cortex and is considered a key molecule for the maintenance of synaptic plasticity and survival of neuronal cells. In addition to neuronal plasticity, BDNF is also important in vascular function, promoting angiogenesis through the regulation of reactive oxygen species (ROS). However, a variant of the BDNF gene in humans, the Val66Met polymorphism (substitution of the amino acid valine for a methionine at position 66 of the codon), occurring in 20-30% of the Caucasian population, may affect plasma BDNF concentrations and its activity in all peripheral tissues containing tyrosine kinase B receptors (TrkB), such as the endothelium. Thus, we will present a discussion about the role of serum BDNF levels in cardiovascular protection, Val66Met genetic variant in vascular reactivity and the effect of physical exercise.

As doenças cardiovasculares (DCV) são atualmente a maior causa de morte no Brasil e no mundo. Em 2016 as DCV foram responsáveis por mais de 17 milhões de mortes, representando 31% de todas as mortes em nível global. Mecanismos moleculares e genéticos podem estar envolvidos na proteção cardiovascular e devem ser considerados nas novas abordagens terapêuticas. Nesse sentido, recentes estudos têm relatado que o Fator Neurotrófico Derivado do Encéfalo (Brain-Derived Neurotrophic Factor, BDNF) está reduzido em indivíduos predispostos a desenvolverem DCV, e que o treinamento físico aeróbio aumenta as quantidades de BDNF circulante. O BDNF é uma neurotrofina encontrada em altas concentrações no hipocampo e córtex cerebral, sendo considerada molécula-chave na manutenção da plasticidade sináptica e na sobrevivência das células neuronais. Além da plasticidade neuronal, BDNF também é importante na função vascular, promovendo angiogênese por meio da regulação por espécies reativas de oxigênio (ROS). Entretanto, uma variante do gene do BDNF em humanos, o polimorfismo Val66Met (substituição do aminoácido valina por uma metionina na posição 66 do códon), que ocorre em 20-30% da população caucasiana, pode afetar as concentrações de BDNF no plasma e sua atividade em todos os tecidos periféricos contendo receptores tirosina quinase B (TrkB), como o endotélio. De fato, recentemente observamos que o polimorfismo Val66Met prejudica a reatividade vascular e o BDNF circulante em resposta ao treinamento físico. Dessa forma, apresentaremos a seguir uma discussão sobre os níveis séricos de BDNF na proteção cardiovascular, a variante genética Val66Met na reatividade vascular e o efeito do exercício físico.

Níveis Séricos do BDNF na Proteção Cardiovascular e em Resposta ao Exercício / Serum Levels of BDNF in Cardiovascular Protection and in Response to Exercise

Resumo As doenças cardiovasculares (DCV) são atualmente a maior causa de morte no Brasil e no mundo. Em 2016 as DCV foram responsáveis por mais de 17 milhões de mortes, representando 31% de todas as mortes em nível global. Mecanismos moleculares e genéticos podem estar envolvidos na proteção cardiovascular e devem ser considerados nas novas abordagens terapêuticas. Nesse sentido, recentes estudos têm relatado que o Fator Neurotrófico Derivado do Encéfalo (Brain-Derived Neurotrophic Factor, BDNF) está reduzido em indivíduos predispostos a desenvolverem DCV, e que o treinamento físico aeróbio aumenta as quantidades de BDNF circulante. O BDNF é uma neurotrofina encontrada em altas concentrações no hipocampo e córtex cerebral, sendo considerada molécula-chave na manutenção da plasticidade sináptica e na sobrevivência das células neuronais. Além da plasticidade neuronal, BDNF também é importante na função vascular, promovendo angiogênese por meio da regulação por espécies reativas de oxigênio (ROS). Entretanto, uma variante do gene do BDNF em humanos, o polimorfismo Val66Met (substituição do aminoácido valina por uma metionina na posição 66 do códon), que ocorre em 20-30% da população caucasiana, pode afetar as concentrações de BDNF no plasma e sua atividade em todos os tecidos periféricos contendo receptores tirosina quinase B (TrkB), como o endotélio. De fato, recentemente observamos que o polimorfismo Val66Met prejudica a reatividade vascular e o BDNF circulante em resposta ao treinamento físico. Dessa forma, apresentaremos a seguir uma discussão sobre os níveis séricos de BDNF na proteção cardiovascular, a variante genética Val66Met na reatividade vascular e o efeito do exercício físico.

Abstract Cardiovascular disease (CVD) is currently the leading cause of death in Brazil and worldwide. In 2016, CVD accounted for more than 17 million deaths, representing 31% of all deaths globally. Molecular and genetic mechanisms may be involved in vascular protection and should be considered in new therapeutic approaches. In this sense, recent studies have reported that brain-derived neurotrophic factor (BDNF) is reduced in individuals predisposed to develop CVD, and that aerobic physical training increases the amounts of circulating BDNF. BDNF is a neurotrophin found at high concentrations in the hippocampus and cerebral cortex and is considered a key molecule for the maintenance of synaptic plasticity and survival of neuronal cells. In addition to neuronal plasticity, BDNF is also important in vascular function, promoting angiogenesis through the regulation of reactive oxygen species (ROS). However, a variant of the BDNF gene in humans, the Val66Met polymorphism (substitution of the amino acid valine for a methionine at position 66 of the codon), occurring in 20-30% of the Caucasian population, may affect plasma BDNF concentrations and its activity in all peripheral tissues containing tyrosine kinase B receptors (TrkB), such as the endothelium. Thus, we will present a discussion about the role of serum BDNF levels in cardiovascular protection, Val66Met genetic variant in vascular reactivity and the effect of physical exercise.

Photobiomodulation by low-level laser therapy in patients with obstructive sleep apnea: Study protocol clinical trial (SPIRIT compliant).

Obstructive sleep apnea (OSA) increases morbidity and mortality and it is associated with an increased cardiovascular risk. The gold standard treatment for OSA is positive airway pressure therapy (CPAP). However, it is an expensive treatment and several patients do not adapt to CPAP. GOAL: The researchers will verify the effects of low-level laser therapy (LLLT) on OSA, when applied to the soft palate and on the tongue base. METHODS: The researchers will select individuals of both sexes aged 30 to 60 years old who are sedentary and that present a high risk of OSA by the Berlin questionnaire. The evaluations pre and post interventions will be polysomnography; anthropometric and body composition measurements (Bioimpedance); metabolic syndrome risk factors (International Diabetes Federation); physical capacity (VO2 peak at the cardiopulmonary exercise test, CPET); endothelial function (flow-mediated dilatation, FMD); autonomic control (heart rate variability and sympathovagal balance). Those diagnosed with moderate and severe OSA (apnea/hypopnea index, AHI ≥15 events/h) will be invited to participate in the study and they will be randomized into 2 groups: LLLT treatment or placebo (C). The LLLT group will receive applications at 8 points on the soft palate and on the base of the tongue for 8 seconds for each point. The applications of LLLT will occur twice a week, with a minimum interval of 2 days between the applications for 2 months, when using a Therapy Plus NS 13678 Laser. The C group will have similar applications, but with the device turned off. EXPECTED RESULTS: In the individuals with OSA, photobiomodulation through LLLT will decrease the AHI. Additionally, when LLLT is applied in the oral cavity, a highly vascularized region, this may cause improvements in the vascular function and in the autonomic and hemodynamic control. ETHICS AND DISSEMINATION: This protocol was approved by the Research Ethics Committee of the Nove de Julho University, São Paulo, Brazil, on the date of March 11, 2019 (CAAE: 06025618.2.0000.5511 - Acceptance Number: 3.191.077). This trial has been registered with the Brazilian Registry of Clinical Trials (REBEC TRIAL RBR-42v548). This study is not yet recruiting. Issue date: November 4, 2019.