No abstract

No abstract

The benefits of physical exercise to reduce low-grade inflammation and improve Brain-Derived Neurotrophic Factor (BDNF) levels and cognitive function became a growing field of interest. Low-grade inflammation is common during aging and seems to be linked to neurodegenerative process. Regular physical exercises can help to reduce pro-inflammatory cytokines levels and to improve BDNF peripheral concentrations. The main goal of this research was to analyze the effects of a 16-week multimodal physical exercise program on peripheral BDNF levels and on Tumor Necrosis-α (TNF-α) and Interleukin- 6 (IL-6) as pro-inflammatory markers in cognitive healthy elderly individuals and in elderly with mild cognitive impairment (MCI). Cognitive functions were assessed by the Montreal Cognitive Assessment (MoCA) prior to and after the intervention. Thirty cognitively healthy participants and thirty-seven MCI participants were assigned to the control (CG) and trained (TG) groups. The TG participated in a multimodal physical training program for a 16-week period. The results showed a significant between-subjects interaction, which indicates the beneficial contribution of training on the reduction of TNF-α (p=0.001) and IL-6 (p<0.001) and on the improvement of BDNF (p<0.001) peripheral concentrations. Cognitive functions also presented significant improvements for MCI trained group (p=0.03). In conclusion, physical exercise was effective to reduce pro-inflammatory cytokines and to improve BDNF peripheral levels, with positive reflexes on cognition. To the best of our knowledge, this is the first study that evaluated longitudinally the effects of a multimodal physical exercises protocol on peripheral concentrations of pro-inflammatory cytokines and cognition performance in elderly MCI individuals.

The benefits of physical exercise on improvements in brain-derived neurotrophic factor (BDNF) levels and cognitive functioning have been reported in the literature. However, the variability of individual responses may be linked to genetic differences. BDNF is considered one of the most plausible factors involved in the cognitive benefits associated with physical activity practice. A single nucleotide polymorphism localized in the gene that codes BDNF results in a missense mutation that promotes an amino acid substitution (Val66Met) in the protein. This process has been associated with decreased levels of BDNF secretion, with corresponding impairments in specific cognitive functions. Therefore, the objective of this study was to analyze the effects of a multimodal physical exercise program on peripheral BDNF levels and cognitive functions in elderly individuals with mild cognitive impairment (MCI). The participants were genotyped for the BDNF Val66Met polymorphism. Cognitive functions were assessed by the Montreal Cognitive Assessment (MoCA) prior to and after the intervention. Forty-five participants were assigned to the control and trained groups. The trained group participated in a multimodal physical training for a 16-week period. The results showed a significant between-subjects interaction (p < 0.05), which indicates the beneficial contribution of training on cognitive functions independent of the BDNF genotype. However, only participants with BDNF-Met genotypes exhibited significant improvements in peripheral BDNF levels. The BDNF genotype appears to modulate the effects of physical exercise on BDNF secretion, but it does not influence cognition. This is the first study that evaluated the influence of a BDNF polymorphism on physical activity and cognition performance in elderly MCI individuals.

The integrin alpha(v)beta(3) is involved in multiple aspects of malignant cancer, including tumor angiogenesis and metastasis, which makes the receptor a key target for the development of anti-cancer therapies. We report here on the production, the characterization and the in vivo anti-angiogenic and anti-metastatic properties of a novel alpha(v)beta(3)-binding disintegrin, DisBa-01, isolated from a cDNA library made with RNAs from the venom gland of Bothrops alternatus. The 11,637 Da-recombinant monomeric form of DisBa-01 displayed an RGD motif and interacted with purified alpha(v)beta(3) integrin in surface plasmon resonance studies, in a dose-dependent and cation sensitive manner. A three-dimensional molecular model of DisBa-01 in complex with alpha(v)beta(3) predicted a large surface of contacts with the beta(3) subunit. DisBa-01 inhibited the adhesion of alpha(v)beta(3)-expressing human microvascular endothelial cell line-1 (HMEC-1) and murine melanoma cell line B16F10 to vitronectin (IC(50) = 555 nM and 225 nM, respectively), and transiently inhibited their proliferation without direct cell toxicity, but did not affect the binding nor the proliferation of a human breast cancer-derived cell line (MDA-MB-231) not expressing alpha(v)beta(3). In vivo, DisBa-01 dose-dependently decreased bFGF-induced angiogenesis in a matrigel plug assay in athymic nude mice (IC(50) = 83 nM). When injected intravenously to C57BL/6 mice together with B16F10 melanoma cells, DisBa-01 time- and dose-dependently inhibited lung metastasis monitored by bioluminescent imaging. We conclude that DisBa-01 is a potent new inhibitor of alpha(v)beta(3)-dependent adherence mechanisms involved in neo-vascularization and tumor metastasis processes.