Louisiana Carolina Ferreira de Meireles

Treadmill exercise induces selective changes in hippocampal histone acetylation during the aging process in rats

Physical exercise and the aging process have been shown to induce opposite effects on epigenetic marks, such as histone acetylation. The impact of exercise on hippocampal histone acetylation on specific lysine residues, especially during the aging process, is rarely studied. The aim of this study was to investigate the effect of treadmill exercise (20min/day during 2 weeks) on H3K9, H4K5 and H4K12 acetylation levels in hippocampi of young adult and aged rats. Male Wistar rats aged 3 or 20-21 months were assigned to sedentary and exercise groups. Single-trial step-down inhibitory avoidance conditioning was employed as an aversive memory paradigm. Hippocampal H3K9, H4K5 and H4K12 acetylation was determined by Western blotting. The daily moderate exercise protocol improved the aversive memory performance and increased hipocampal H4K12 acetylation levels in both tested ages. Exercise was also able to increase H3K9 acetylation levels in aged rats. An age-related decline in memory performance was observed, without any effect of the aging process on histone acetylation state. Our data suggest that treadmill exercise can impact hippocampal the histone acetylation profile in an age- and lysine-dependent manner. In addition, higher hippocampal H4K12 acetylation levels at both ages may be related to improvement of aversive memory performance.

Treadmill exercise alters histone acetylation differently in rats exposed or not exposed to aversive learning context

Epigenetic modifications have been linked to memory formation after learning context exposure and to exercise effects on memory performance. The aim of this study was to investigate the effect of treadmill exercise (20 min/day during 2 weeks) on H3K14 acetylation and H3S10 phosphorylation levels in the hippocampi of 3-month-old Wistar rats exposed and not exposed to aversive learning context. Male Wistar rats aged 2-3 months were assigned to non-exercised (sedentary) and exercised (running daily for 20 min for 2 weeks) groups. Single-trial step-down inhibitory avoidance (IA) conditioning was employed as an aversive memory model. Epigenetic parameters were determined 30 min after the IA test. A decrease in the H3K14 acetylation in the hippocampus 24 h after IA training (30 min after test session) was observed. Exercise reversed the IA effect, and no effect was observed in the non-IA exposed group. Our data support the hypothesis that modulation of H3K14 acetylation levels in the hippocampus might be related, at least in part, to exercise effects on aversive memory.

Treadmill exercise induces age and protocol-dependent epigenetic changes in prefrontal cortex of Wistar rats.

Some studies have linked age-related beneficial effects of exercise and epigenetic mechanisms. Although, the impact of treadmill exercise on histone acetylation, histone and DNA methylation marks in aged cortices yet remains poorly understood. Considering the role of frontal cortex on brain functions, we investigated the potential of different exercise protocols, single session and daily exercise, to modulate epigenetic marks, namely global H4 acetylation, histone methyltransferase activity (HMT H3K27) and levels of DNA methytransferase (DNMT1 and DNMT3b) in prefrontal cortices from 3 and 21-months aged Wistar rats. The animals were submitted to two treadmill exercise protocols, single session (20min) or daily moderate (20min/day during 14days). The daily exercise protocol induced an increased in histone H4 acetylation levels in prefrontal cortices of 21-months-old rats, without any effects in young adult group. DNMT3b levels were increased in aged cortices of animals submitted to single session of exercise. These results indicate that prefrontal cortex is susceptible to epigenetic changes in a protocol dependent-manner and that H4 acetylation levels and DNMT3b content changes might be linked at least in part to exercise-induced effects on brain functions.

Aging process alters hippocampal and cortical secretase activities of Wistar rats

HighlightsAged brains have an imbalance between amyloidogenic and non‐amyloidogenic pathways.Lower cortical TACE activity was linked to aging‐induced aversive memory impairment.Treadmill exercise was unable to alter hippocampal and cortical secretase activities. ABSTRACT A growing body of evidence has demonstrated amyloid plaques in aged brain; however, little attention has been given to amyloid precursor protein (APP) processing machinery during the healthy aging process. The amyloidogenic and non‐amyloidogenic pathways, represented respectively by &bgr;‐ and &agr;‐secretases (BACE and TACE), are responsible for APP cleavage. Our working hypothesis is that the normal aging process could imbalance amyloidogenic and non‐amyloidogenic pathways specifically BACE and TACE activities. Besides, although it has been showed that exercise can modulate secretase activities in Alzheimer Disease models the relationship between exercise effects and APP processing during healthy aging process is rarely studied. Our aim was to investigate the aging process and the exercise effects on cortical and hippocampal BACE and TACE activities and aversive memory performance. Young adult and aged Wistar rats were subjected to an exercise protocol (20 min/day for 2 weeks) and to inhibitory avoidance task. Biochemical parameters were evaluated 1 h and 18 h after the last exercise session in order to verify transitory and delayed exercise effects. Aged rats exhibited impaired aversive memory and diminished cortical TACE activity. Moreover, an imbalance between TACE and BACE activities in favor of BACE activity was observed in aged brain. Moderate treadmill exercise was unable to alter secretase activities in any brain areas or time points evaluated. Our results suggest that aging‐related aversive memory decline is partly linked to decreased cortical TACE activity. Additionally, an imbalance between secretase activities can be related to the higher vulnerability to neurodegenerative diseases induced by aging.

Avaliação da capacidade funcional de crianças com paralisia cerebral

Purpose to describe the functional capacity of children with cerebral palsy who performed the care of Physical Therapy Specialty and Speech, Language and Hearing Sciences. Methods a cross sectional observational study, comprising 14 children with spastic quadriplegic (6 performed Physiotherapy and 8 performed Physiotherapy and Speech therapy). The Pediatric Evaluation of Disability Inventory (PEDI) and the Manual Abilities Classification System (GMFCS) were used to evaluate them. The associations between categorical variables were analyzed using Fisher exact test. Comparisons between means were performed using the Student t test. Results we didn’t obtain statistically significant improvement in the areas of self-care, mobility and social function between the two groups in the fields of functional skills and caregiver assistance. Conclusion the Physiotherapy group of children had higher functional scores than those in the Physiotherapy group associated with Speech Therapy, but there was no statistically significant difference between the groups. This was probably due to the small number of participants, the diversity of clinical presentation and possible differences of Physical Therapy intervention conducted in two states with very different socioeconomic situations.

Eficácia da eletroestimulação muscular expiratória na tosse de pacientes após acidente vascular encefálico

Individuos com sequelas de acidente vascular encefalico (AVE) apresentam como complicacao comum a hipotonia de tronco com consequente fraqueza da sua musculatura, em especial, o reto abdominal que e o principal musculo acionado para a tosse. As correntes eletricas tem sido amplamente utilizadas para recrutamento de fibras musculares nas mais diversas patologias. O presente estudo teve como objetivo avaliar a eficacia da eletroestimulacao transcutânea de media frequencia (ETMF) na forca muscular expiratoria e tosse de pacientes com sequela de AVE. Trata-se de um estudo quase-experimental (antes e depois) onde foram selecionados 11 individuos pos-AVE entre 40 a 65 anos, ambos os sexos e estaveis hemodinamicamente. Os pacientes foram avaliados quanto a parâmetros clinicos e pneumofuncionais (ventilometria, pico de fluxo expiratorio (PFE) e manovacuometria) e submetidos ao protocolo, que constava de ETMF no musculo reto abdominal com o aparelho de corrente Russa, frequencia portadora de 2.500 Hz modulada a 40 Hz, durante 15 minutos, por 15 sessoes. Na avaliacao inicial observou-se diminuicao da forca muscular inspiratoria e expiratoria (Pimax; Pemax) e do PFE quando comparados aos valores de normalidade preditos na literatura. Apos a ETMF houve incremento da Pimax e Pemax sem significância estatistica (p=0,18 e p=0,29) ja o PFE teve um acrescimo de 283,73 L/minuto para 347,27 L/minuto (p=0,03). Pode-se observar que a ETMF foi eficaz no incremento dos parâmetros avaliados, com o PFE sendo o de maior impacto e significância estatistica, no entanto, mais estudos com populacoes maiores se fazem necessarios para analise dessa nova abordagem terapeutica.

Acute exercise and periodized training in different environments affect histone deacetylase activity and interleukin-10 levels in peripheral blood of patients with type 2 diabetes

AIMS Our purpose was to investigate the effects of aerobic periodized training in aquatic and land environments on plasma histone deacetylase (HDAC) activity and cytokines levels in peripheral blood of diabetes mellitus type 2 (T2DM) patients. METHODS The patients underwent 12 weeks of periodized training programs that including walking or running in a swimming pool (aquatic group) or in a track (dry land group). Blood samples were collected immediately before and after both first and last sessions. Plasma cytokine levels and HDAC activity in peripheral blood mononuclear cell (PBMC) was measured. RESULTS The exercise performed in both environments similarly modulated the evaluated acetylation mark, global HDAC activity. However, a differential profile depending on the evaluated time point was detected, since exercise increased acutely HDAC activity in sedentary and after 12 weeks of training period, while a reduced HDAC activity was observed following periodized training (samples collected before the last session). Additionally, the 12 weeks of periodized exercise in both environments increased IL-10 levels. CONCLUSIONS Our data support the hypothesis that the modulation of HDAC activity and inflammatory status might be at least partially related to exercise effects on T2DM. The periodized training performed in both aquatic and land environments impacts similarly epigenetic and inflammatory status.