All roads lead to Rome-a review of the potential mechanisms by which exerkines exhibit neuroprotective effects in Alzheimer’s disease

Age-related neurodegenerative disorders such as Alzheimer’s disease(AD)have become a critical public health issue due to the significantly extended human lifespan,leading to considerable economic and social burdens.Traditional therapies for AD such as medicine and surgery remain ineffective,impractical,and expensive.Many studies have shown that a variety of bioactive substances released by physical exercise(called“exerkines”)help to maintain and improve the normal functions of the brain in terms of cognition,emotion,and psychomotor coordination.Increasing evidence suggests that exerkines may exert beneficial effects in AD as well.This review summarizes the neuroprotective effects of exerkines in AD,focusing on the underlying molecular mechanism and the dynamic expression of exerkines after physical exercise.The findings described in this review will help direct research into novel targets for the treatment of AD and develop customized exercise therapy for individuals of different ages,genders,and health conditions.

Associations between physical activity levels and ATPase inhibitory factor 1 concentrations in older adults

Background:Adenosine triphosphatase inhibitory factor 1(IF1)is a key protein involved in energy metabolism.IF1 has been linked to various agerelated diseases,although its relationship with physical activity(PA)remains unclear.Additionally,the apolipoprotein A-I(apoA-I),a PA-modulated lipoprotein,could play a role in this relationship because it shares a binding site with IF1 on the cell-surface ATP synthase.We examined here the associations between chronic PA and plasma IF1 concentrations among older adults,and we investigated whether apoA-I mediated these associations.Methods:In the present work,1096 healthy adults(63.8%females)aged 70 years and over who were involved in the Multidomain Alzheimer Prevention Trial study were included.IF1 plasma concentrations(square root of ng/mL)were measured at the 1-year visit of the Multidomain Alzheimer Prevention Trial,while PA levels(square root of metabolic equivalent task min/week)were assessed using questionnaires administered each year from baseline to the 3-year visit.Multiple linear regressions were performed to investigate the associations between the first-year mean PA levels and IF1 concentrations.Mediation analyses were conducted to examine whether apoA-I mediated these associations.Mixedeffect linear regressions were carried out to investigate whether the 1-year visit IF1 concentrations predicted subsequent changes in PA.Results:Multiple linear regressions indicated that first-year mean PA levels were positively associated with IF1 concentrations(B=0.021;SE=0.010;p=0.043).Mediation analyses revealed that about 37.7%of this relationship was mediated by apoA-I(B_(ab)=0.008;SE=0.004;p=0.023).Longitudinal investigations demonstrated that higher concentrations of IF1 at the 1-year visit predicted a faster decline in PA levels over the subsequent 2 years(time×IF1:B=0.148;SE=0.066;p=0.025).Conclusion:This study demonstrates that regular PA is associated with plasma IF1 concentrations,and it suggests that apoA-I partly mediates this association.Additionally,this study finds that baseline concentrations of IF1 can predict future changes in PA.However,further research is needed to fully understand the mechanisms underlying these observations.

Exercise promotes angiogenesis by enhancing endothelial cell fatty acid utilization via liver-derived extracellular vesicle miR-122-5p

Background:Angiogenesis constitutes a major mechanism responsible for exercise-induced beneficial effects.Our previous study identified a cluster of differentially expressed extracellular vesicle microRNAs(miRNAs)after exercise and found that some of them act as exerkines.However,whether these extracellular vesicle miRNAs mediate the exercise-induced angiogenesis remains unknown.Methods:A 9-day treadmill training was used as an exercise model in C57BL/6 mice.Liver-specific adeno-associated virus 8 was used to knock down microRNA-122-5p(miR-122-5p).Human umbilical vein endothelial cells were used in vitro.Results:Among these differentially expressed extracellular vesicle miRNAs,miR-122-5p was identified as a potent pro-angiogenic factor that activated vascular endothelial growth factor signaling and promoted angiogenesis both in vivo and in vitro.Exercise increased circulating levels of miR-122-5p,which was produced mainly by the liver and shuttled by extracellular vesicles in mice.Inhibition of circulating miR-122-5p or liver-specific knockdown of miR-122-5p significantly abolished the exercise-induced pro-angiogenic effect in skeletal muscles,and exerciseimproved muscle performance in mice.Mechanistically,miR-122-5p promoted angiogenesis through shifting substrate preference to fatty acids in endothelial cells,and miR-122-5p upregulated endothelial cell fatty-acid utilization by targeting 1-acyl-sn-glycerol-3-phosphate acyltransferase(AGPAT1).In addition,miR-122-5p increased capillary density in perilesional skin tissues and accelerated wound healing in mice.Conclusion:These findings demonstrated that exercise promotes angiogenesis through upregulation of liver-derived extracellular vesicle miR-122-5p,which enhances fatty acid utilization by targeting AGPAT1 in endothelial cells,highlighting the therapeutic potential of miR-122-5p in tissue repair.