Inhibitory control after aerobic exercise with and without blood flow restriction in older adults / Controle inibitório após exercícios aeróbicos com e sem restrição do fluxo sanguíneo em idosos / Control inhibitorio después del ejercicio aeróbico con y sin restricción del flujo sanguíneo en adultos mayores

Introduction: Regular aerobic exercise (AE) can reduce the cognitive losses typically experienced with aging can be blunted by regular aerobic exercise (AE). AE also induces acute improvement of cognitive function among older adults; and AE practice with blood flow restriction (BFR) addss other benefits to elderly health, such as improvements in aerobic fitness, and increase in muscle mass and strength, however, it is not clear which EA protocol is more efficient to cognitive function. Objectives: Thus, the aimof this study was to compare AE protocols with and without BFR on the inhibitory control of the elderly. Methodology: Twenty-one elderly performed the Stroop test before and after three AE sessions in a repeated measure, cross-over design: AE with high load (70% VO2max), AE with low load (40% VO2max), and AE with blood flow restriction (AE-BFR) BFR (40% VO2max and 50% of BFR). Results and discussion: There was no significant effect from experimental sessions on cognitive function, assessed by inhibitory control in Stroop test. Perhaps, the load applied was not proper to stimulate cognitive function improvements, as seen the moderate loads have been more efficient to increase cerebral blood flow, among other physiological mechanisms encompassed. Final Considerations: Moreover, we observed very heterogeneous responses among individuals and sessions, suggesting that future research also considers biological individuality.

Introdução: As perdas cognitivas tipicamente experimentadas com o envelhecimento podem ser atenuadas por exercícios aeróbicos (EA) regulares. EA também induz melhora aguda da função cognitiva em idosos; e a prática de EA com restrição de fluxo sanguíneo (RFS) agrega outros benefícios à saúde do idoso, como melhorias na aptidão aeróbia e aumento da massa e força muscular. No entanto, não está claro qual protocolo de EA é mais eficaz para a funcao cognitiva. Objetivos: Assim, o objetivo deste estudo foi comparar diferentes protocolos de EA com e sem RFS no controle inibitório de idosos. Metodologia: Vinte e um idosos realizaram o teste de Stroop antes e após três sessões de EA em medida repetida, desenho cruzado: EA com alta carga (70% VO2máx), EA com baixa carga (40% VO2máx) e EA com RFS (40% VO2máx e 50% do RFS). Resultados e discussão: Não houve efeito significativo das sessões experimentais na função cognitiva avaliada pelo controle inibitório no Stroop Test. Talvez, as cargas aplicadas não tenham sido adequadas para estimular melhorias no controle inibitório, visto que as cargas moderadas têm sido mais eficientes para aumentar o fluxo sanguíneo cerebral, entre outros mecanismos fisiológicos Considerações Finais: Além disso, observamos respostas bastante heterogêneas entre indivíduos e sessões, sugerindo que pesquisas futuras considere também a individualidade biológica.

Introducción: El ejercicio aeróbico regular (EA) puede reducir la perdida cognitiva tipicamente experimentada durante el envejecimiento. EA puede tambien inducir mejora en la funcion cognitiva entre adultos mayores, ademas, la practica de resticcion de flujo sanguíneo (RFS) agrega otros beneficios para la salud en los ancianos, así como mejoras en la aptitud aeróbica, aumento de la masa muscular y la fuerza, sin embargo, no está claro qué protocolo de EA es más eficiente para la función cognitiva. Objetivos: El objetivo de este estudio fue comparar los protocolos de EA con y sin RFS en el control inhibitorio de los ancianos. Metodología: Veintiún ancianos realizaron la prueba de Stroop antes y después de tres sesiones de EA en medida repetida, diseño cruzado: EA con carga alta (70% VO2max), EA con carga baja (40% VO2max) y EA con restricción del flujo sanguíneo (EA-RFS) RFS (40% VO2max y 50% de RFS). Resultados y discusión: No hubo efecto significativo de las sesiones experimentales sobre la función cognitiva, evaluada por el control inhibitorio en la prueba de Stroop. Quizás, la carga aplicada no fue la adecuada para estimular mejoras en la función cognitiva, ya que las cargas moderadas han sido más eficientes para aumentar el flujo sanguíneo cerebral, entre otros mecanismos fisiológicos englobados. Consideraciones finales: Además, nosotros observamos respuestas muy heterogéneas entre individuos y sesiones, lo que sugiere que para futuras investigaciones también se debe considerar la variabilidad biológica.

Amphetamine sensitization alters hippocampal neuronal morphology and memory and learning behaviors.

It is known that continuous abuse of amphetamine (AMPH) results in alterations in neuronal structure and cognitive behaviors related to the reward system. However, the impact of AMPH abuse on the hippocampus remains unknown. The aim of this study was to determine the damage caused by AMPH in the hippocampus in an addiction model. We reproduced the AMPH sensitization model proposed by Robinson et al. in 1997 and performed the novel object recognition test (NORt) to evaluate learning and memory behaviors. After the NORt, we performed Golgi-Cox staining, a stereological cell count, immunohistochemistry to determine the presence of GFAP, CASP3, and MT-III, and evaluated oxidative stress in the hippocampus. We found that AMPH treatment generates impairment in short- and long-term memories and a decrease in neuronal density in the CA1 region of the hippocampus. The morphological test showed an increase in the total dendritic length, but a decrease in the number of mature spines in the CA1 region. GFAP labeling increased in the CA1 region and MT-III increased in the CA1 and CA3 regions. Finally, we found a decrease in Zn concentration in the hippocampus after AMPH treatment. An increase in the dopaminergic tone caused by AMPH sensitization generates oxidative stress, neuronal death, and morphological changes in the hippocampus that affect cognitive behaviors like short- and long-term memories.

Effects of metallothionein-3 and metallothionein-1E gene transfection on proliferation, cell cycle, and apoptosis of esophageal cancer cells.

Metallothionein (MT)-3 has cell growth inhibitory activity, and is the only currently known MT subtype with unique physiological functions. The expression levels of MT-1E, a subtype of MT-1, were positively correlated with the degree of esophageal cancer malignancy. The present study aimed to investigate the effects of MT-3 and MT-1E gene transfection on the proliferation, cell cycle, and apoptosis of esophageal cancer cells. The cationic liposome method was used to transfect the esophageal cancer strains Eca-109 and TE13. Reverse transcription-polymerase chain reaction was used to detect target gene expression, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction was applied to detect cell proliferation, and flow cytometry was used for cell cycle and apoptosis detection. Esophageal cancer cells with MT-3 and MT-1E gene transfection showed high expression of the foreign target gene and mRNA. Cells with MT-3 gene transfection showed markedly inhibited proliferation (P < 0.05), a significantly higher proportion of cells in the G0/G1 phase (P < 0.05), a significantly lower proportion of cells in the S phase (P < 0.05), and a significantly increased apoptosis rate (P < 0.05). Cells with MT-1E gene transfection did not show significant changes in proliferation, cell cycle, or apoptosis rate (P > 0.05). Therefore, the upregulation of MT-3 gene expression can inhibit esophageal cancer cell proliferation and induce apoptosis, which may be achieved by blocking the tumor cell growth cycle, whereas effects of the MT-1E gene on the proliferation of esophageal cancer cells were not evident.

Metallothionein 3 attenuated the apoptosis of neurons in the CA1 region of the hippocampus in the senescence-accelerated mouse/PRONE8 (SAMP8).

OBJECTIVE: Metallothionein 3 (MT-3) has been shown to protect against apoptotic neuronal death in the brains of patients with Alzheimer's disease. Zinc is a potent inhibitor of caspase-3 and its deficiency was found to promote apoptosis. Here, we measured the zinc and copper content in the brains of senescence-accelerated mouse/PRONE8 (SAMP8) and sought to investigate the effect of MT-3 on the apoptosis of neurons in the hippocampal CA1 region of these mice. METHOD: The zinc and copper content in the brain samples of SAMP8 and normal control SAMR1 mice were determined using an atomic absorption spectrophotometer. The mice were administered intraperitoneally for four weeks with MT-3 or MT1 and thereafter apoptosis was measured using the TUNEL method and the expression of anti-apoptotic protein Bcl-2 and proapoptotic protein Bax was examined by immunohistochemistry. RESULTS: Compared with that in SMAR1 mice, the content of zinc in the brains of SAMP8 mice was significantly reduced (P<0.05). Moreover, significant levels of apoptosis of neurons were observed in the hippocampus of SAMP8 mice, which, compared with those in SMAR1 mice, also showed significantly lower levels of Bcl-2 and higher levels of Bax (P<0.05). MT-3 increased zinc concentration in the hippocampus of SAMP8 mice and also significantly decreased apoptosis in these neurons dose-dependently and increased the levels of Bcl-2 and decreased the levels of Bax. CONCLUSION: MT-3 could attenuate apoptotic neuron death in the hippocampus of SAMP8, suggesting that the protein may lessen the development of neurodegeneration.

Metallothionein isoform 3 gene is differentially expressed in corticotropin-producing pituitary adenomas.

In order to search for candidate genes related to pituitary adenoma aggressiveness, the present investigation was intended to compare the mRNA expression profile from a pool of four nonfunctional pituitary adenomas (NFPA) with a spinal cord metastasis of a nonfunctional pituitary carcinoma (MNFPC). The metallothionein isoform 3 (MT3) gene was differentially expressed in nonfunctional adenomas in comparison to the metastasis of nonfunctional carcinoma. A microarray dataset comprising 19,881 probes was employed for comparing expression profiles of a spinal cord metastasis of a nonfunctional pituitary carcinoma with a pool of four nonfunctional pituitary adenomas. RT-qPCR confirmed the microarray findings and was used to investigate MT3 mRNA gene expression in tumor samples of a series of 52 different pituitary adenoma subtypes comprising 10 corticotropin (ACTH)-producing, 18 growth hormone (GH)-producing, 8 prolactin (PRL)-producing, and 16 nonfunctional adenomas. Microarray data analysis by GeneSifter program unveiled Gene Ontology terms related to zinc ion-binding activity closely related to MT3 function. MT3 mRNA expression was statistically significantly higher in ACTH-producing pituitary adenomas and in nonfunctional pituitary adenomas in comparison to the other pituitary adenoma subtypes. The more abundant expression of this gene in ACTH-producing pituitary adenomas suggests that MT3 could be related to distinct pituitary cell lineage regulating the activity of some transcription factor of importance in hormone production and/or secretion.