bims-empneu 2021-03-21 papers

Front Physiol. 2021 ;12 629914

Elevated Lactate by High-Intensity Interval Training Regulates the Hippocampal BDNF Expression and the Mitochondrial Quality Control System.

Jingyun Hu, Ming Cai, Qinghui Shang, Zhaorun Li, Yu Feng, Beibei Liu, Xiangli Xue, Shujie Lou.

High-intensity interval training (HIIT) is reported to be beneficial to brain-derived neurotrophic factor (BDNF) biosynthesis. A key element in this may be the existence of lactate, the most obvious metabolic product of exercise. In vivo, this study investigated the effects of a 6-week HIIT on the peripheral and central lactate changes, mitochondrial quality control system, mitochondrial function and BDNF expression in mouse hippocampus. In vitro, primary cultured mice hippocampal cells were used to investigate the role and the underlying mechanisms of lactate in promoting mitochondrial function during HIIT. In vivo studies, we firstly reported that HIIT can potentiate mitochondrial function [boost some of the mitochondrial oxidative phosphorylation (OXPHOS) genes expression and ATP production], stimulate BDNF expression in mouse hippocampus along with regulating the mitochondrial quality control system in terms of promoting mitochondrial fusion and biogenesis, and suppressing mitochondrial fission. In parallel to this, the peripheral and central lactate levels elevated immediately after the training. In vitro study, our results revealed that lactate was in charge of regulating mitochondrial quality control system for mitochondrial function and thus may contribute to BDNF expression. In conclusion, our study provided the mitochondrial mechanisms of HIIT enhancing brain function, and that lactate itself can mediate the HIIT effect on mitochondrial quality control system in the hippocampus.

Keywords: BDNF; High-intensity interval training; lactate; mitochondrial quality control system; mouse hippocampus

DOI: https://doi.org/10.3389/fphys.2021.629914

Mol Biol Rep. 2021 Mar 15.

Interval aerobic training improves bioenergetics state and mitochondrial dynamics of different brain regions in restraint stressed rats.

Fariba Khodagholi, Shima Zareh Shahamati, Mona Maleki Chamgordani, Maryam Alsadat Mousavi, Mehdi Moslemi, Mojtaba Salehpour, Shahrbanoo Rafiei, Forough Foolad.

Evidence has validated the prophylactic effects of exercising on different aspects of health. On the opposite side, immobilization may lead to various destructive effects causing neurodegeneration. Here, we investigated the association between exercising and mitochondrial quality for preventing the destructive effects of restraint stress in different rat brain regions. Twenty-four male Wistar rats, were randomized into four groups (n = 6), exercise, stress, exercise + stress, and control. The exercise procedure consisted of running on a rodent treadmill for 8 weeks, and rats in the stress group were immobilized for 6 h. Rats were then euthanized by decapitation and tricarboxylic acid (TCA) cycle enzyme activity, antioxidant levels, and mitochondrial biogenesis factors were assessed in the frontal, hippocampus, parietal and temporal regions using spectrophotometer and western blot technique. Based on our results, increased activity of TCA cycle enzymes in the exercised and exercise-stressed groups was detected, except for malate dehydrogenase which was decreased in exercise-stressed group, and fumarase that did not change. Furthermore, the level of antioxidant agents (superoxide dismutase and reduced glutathione), mitochondrial biogenesis factors (peroxisome proliferator-activated receptor gamma coactivator 1-alpha and mitochondrial transcription factor A), and dynamics markers (Mitofusin 2, dynamic related protein 1, PTEN induced putative kinase-1, and parkin) increased in both mentioned groups. Interestingly our results also revealed that the majority of the mitochondrial factors increased in the frontal and parietal lobes, which may be in relation with the location of motor and sensory areas. Exercise can be used as a prophylactic approach against bioenergetics and mitochondrial dysfunction.

Keywords: Aerobic exercise; Endogenous antioxidants; Mitochondrial biogenesis; Mitochondrial dynamics; Restraint stress; Tricarboxylic acid cycle

DOI: https://doi.org/10.1007/s11033-021-06177-4

Med J Aust. 2021 Mar 14.

Dementia prevention: the time to act is now.

NHMRC National Institute for Dementia Research, Dementia Prevention Special Interest Group*

Keywords: Alzheimer disease; Dementia; Neurocognitive disorders; Prevention and control; Public health; Risk factors

DOI: https://doi.org/10.5694/mja2.50972

Am J Clin Nutr. 2021 Mar 19. pii: nqab018. [Epub ahead of print]

Exercise, diet, and cognition in a 4-year randomized controlled trial: Dose-Responses to Exercise Training (DR's EXTRA).

Pirjo Komulainen, Jaakko Tuomilehto, Kai Savonen, Reija Männikkö, Maija Hassinen, Timo A Lakka, Tuomo Hänninen, Vesa Kiviniemi, David R Jacobs, Miia Kivipelto, Rainer Rauramaa.

BACKGROUND: Evidence for the effects of exercise and dietary interventions on cognition from long-term randomized controlled trials (RCTs) in large general populations remains insufficient.
OBJECTIVE: The objective of our study was to investigate the independent and combined effects of resistance and aerobic exercise and dietary interventions on cognition in a population sample of middle-aged and older individuals.
METHODS: We conducted a 4-y RCT in 1401 men and women aged 57-78 y at baseline. The participants were randomly assigned to the resistance exercise, aerobic exercise, diet, combined resistance exercise and diet, combined aerobic exercise and diet, or control group. Exercise goals were at least moderate-intensity resistance exercise ≥2 times/wk and at least moderate-intensity aerobic exercise ≥5 times/wk. Dietary goals were ≥400 g/d of vegetables, fruit, and berries; ≥2 servings of fish/wk; ≥14 g fiber/1000 kcal; and ≤10% of energy of daily energy intake from SFAs. The primary outcome was the change in global cognition measured by the total score of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) neuropsychological tests [CERAD total score (CERAD-TS)]. The data were analyzed using the intention-to-treat principle and linear mixed-effects models.
RESULTS: There was a trend toward improved CERAD-TS over 4 y in the combined aerobic exercise and diet group compared with the control group (net increase: 1.4 points; 95% CI: 0.1, 2.7; P = 0.06) adjusted for age, sex, years of education, symptoms of depression, and waist circumference at baseline. No other differences in CERAD-TS changes were found across the 6 study groups. Diet did not potentiate the effect of aerobic or resistance exercise on CERAD-TS.
CONCLUSIONS: A combination of at least moderate-intensity aerobic exercise and a healthy diet may improve cognition in older individuals over 4 y, but there was no effect of either of these interventions alone, resistance training alone, or resistance exercise with a healthy diet on cognition.

Keywords: aerobic exercise; cognitive function; healthy diet; older individuals; resistance exercise

DOI: https://doi.org/10.1093/ajcn/nqab018