scholarly journals The Protective Effects of Apigenin on Cognitive Function and The Brain Transcriptome in Old Mice

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. 687-687
Author(s):  
Alyssa Cavalier ◽  
Zachary Clayton ◽  
David Hutton ◽  
Cali McEntee ◽  
Douglas Seals ◽  
...  

Abstract Age-related declines in cognitive function increase the risk of developing mild cognitive impairment and dementia, but select nutraceuticals (bioactive plant compounds) may hold promise for protecting the brain and improving cognitive function with age. Apigenin is a flavonoid nutraceutical found in chamomile and reported to inhibit multiple hallmarks of aging; however, it has not been studied in the context of brain aging specifically. We treated young (6 mo) and old (27 mo) C57BL/6N mice with apigenin (0.5 mg/mL in 0.2% carboxymethylcellulose) or control (0.2% carboxymethylcellulose) drinking water for 6 weeks. Then, we assessed cognitive function and performed RNA-seq to characterize global transcriptomic changes and potential mechanisms of action in the brain. We observed impaired novel object recognition (NOR) test performance (an index of learning/memory) in old vs. young control mice (P<0.0001), but old apigenin mice had ~3-fold higher NOR performance relative to old control mice (P=0.02). Transcriptomic analyses also showed age-associated gene expression changes related to immune function and inflammation, consistent with the established role of inflammation in brain aging. However, some of these key changes were reversed by apigenin. In fact, >300 genes were differentially expressed in old apigenin-treated mice vs. old controls, and the biological processes linked with these differences were related to innate and adaptive immune function, and cytokine and chemokine regulation. We are performing protein/signaling pathway analyses to elucidate downstream cellular changes associated with apigenin treatment, but our current results suggest apigenin may be a promising nutraceutical candidate for preventing brain aging.

Cells ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2531
Author(s):  
Amandine Grimm

The brain is the most energy-consuming organ of the body and impairments in brain energy metabolism will affect neuronal functionality and viability. Brain aging is marked by defects in energetic metabolism. Abnormal tau protein is a hallmark of tauopathies, including Alzheimer’s disease (AD). Pathological tau was shown to induce bioenergetic impairments by affecting mitochondrial function. Although it is now clear that mutations in the tau-coding gene lead to tau pathology, the causes of abnormal tau phosphorylation and aggregation in non-familial tauopathies, such as sporadic AD, remain elusive. Strikingly, both tau pathology and brain hypometabolism correlate with cognitive impairments in AD. The aim of this review is to discuss the link between age-related decrease in brain metabolism and tau pathology. In particular, the following points will be discussed: (i) the common bioenergetic features observed during brain aging and tauopathies; (ii) how age-related bioenergetic defects affect tau pathology; (iii) the influence of lifestyle factors known to modulate brain bioenergetics on tau pathology. The findings compiled here suggest that age-related bioenergetic defects may trigger abnormal tau phosphorylation/aggregation and cognitive impairments after passing a pathological threshold. Understanding the effects of aging on brain metabolism may therefore help to identify disease-modifying strategies against tau-induced neurodegeneration.


2013 ◽  
Vol 15 (1) ◽  
pp. 109-119 ◽  

Is it possible to enhance neural and cognitive function with cognitive training techniques? Can we delay age-related decline in cognitive function with interventions and stave off Alzheimer's disease? Does an aged brain really have the capacity to change in response to stimulation? In the present paper, we consider the neuroplasticity of the aging brain, that is, the brain's ability to increase capacity in response to sustained experience. We argue that, although there is some neural deterioration that occurs with age, the brain has the capacity to increase neural activity and develop neural scaffolding to regulate cognitive function. We suggest that increase in neural volume in response to cognitive training or experience is a clear indicator of change, but that changes in activation in response to cognitive training may be evidence of strategy change rather than indicative of neural plasticity. We note that the effect of cognitive training is surprisingly durable over time, but that the evidence that training effects transfer to other cognitive domains is relatively limited. We review evidence which suggests that engagement in an environment that requires sustained cognitive effort may facilitate cognitive function.


2016 ◽  
Vol 5 (1) ◽  
pp. 30-38 ◽  
Author(s):  
Jennifer J. Heisz ◽  
Ana Kovacevic

Age-related changes in the brain can compromise cognitive function. However, in some cases, the brain is able to functionally reorganize to compensate for some of this loss. The present paper reviews the benefits of exercise on executive functions in older adults and discusses a potential mechanism through which exercise may change the way the brain processes information for better cognitive outcomes. Specifically, older adults who are more physically active demonstrate a shift toward local neural processing that is associated with better executive functions. We discuss the use of neural complexity as a sensitive measure of the neural network plasticity that is enhanced through exercise. We conclude by highlighting the future work needed to improve exercise prescriptions that help older adults maintain their cognitive and physical functions for longer into their lifespan.


2019 ◽  
pp. 105-112
Author(s):  
Risto Näätänen ◽  
Teija Kujala ◽  
Gregory Light

This chapter shows that MMN and its magnetoencephalographic (MEG) equivalent MMNm are sensitive indices of aging-related perceptual and cognitive decline. Importantly, the age-related neural changes are associated with a decrease of general brain plasticity, i.e. that of the ability of the brain to form and maintain sensory-memory traces, a necessary basis for veridical perception and appropriate cognitive brain function. MMN/MMNm to change in stimulus duration is particularly affected by aging, suggesting the increased vulnerability of temporal processing to brain aging and accounting, for instance, for a large part of speech-perception difficulties of the aged beyond the age-related peripheral hearing loss.


2019 ◽  
Vol 57 (3) ◽  
pp. 1317-1331 ◽  
Author(s):  
Gavin Pharaoh ◽  
Daniel Owen ◽  
Alexander Yeganeh ◽  
Pavithra Premkumar ◽  
Julie Farley ◽  
...  

AbstractAge-related decline in circulating levels of insulin-like growth factor (IGF)-1 is associated with reduced cognitive function, neuronal aging, and neurodegeneration. Decreased mitochondrial function along with increased reactive oxygen species (ROS) and accumulation of damaged macromolecules are hallmarks of cellular aging. Based on numerous studies indicating pleiotropic effects of IGF-1 during aging, we compared the central and peripheral effects of circulating IGF-1 deficiency on tissue mitochondrial function using an inducible liver IGF-1 knockout (LID). Circulating levels of IGF-1 (~ 75%) were depleted in adult male Igf1f/f mice via AAV-mediated knockdown of hepatic IGF-1 at 5 months of age. Cognitive function was evaluated at 18 months using the radial arm water maze and glucose and insulin tolerance assessed. Mitochondrial function was analyzed in hippocampus, muscle, and visceral fat tissues using high-resolution respirometry O2K as well as redox status and oxidative stress in the cortex. Peripherally, IGF-1 deficiency did not significantly impact muscle mass or mitochondrial function. Aged LID mice were insulin resistant and exhibited ~ 60% less adipose tissue but increased fat mitochondrial respiration (20%). The effects on fat metabolism were attributed to increases in growth hormone. Centrally, IGF-1 deficiency impaired hippocampal-dependent spatial acquisition as well as reversal learning in male mice. Hippocampal mitochondrial OXPHOS coupling efficiency and cortex ATP levels (~ 50%) were decreased and hippocampal oxidative stress (protein carbonylation and F2-isoprostanes) was increased. These data suggest that IGF-1 is critical for regulating mitochondrial function, redox status, and spatial learning in the central nervous system but has limited impact on peripheral (liver and muscle) metabolism with age. Therefore, IGF-1 deficiency with age may increase sensitivity to damage in the brain and propensity for cognitive deficits. Targeting mitochondrial function in the brain may be an avenue for therapy of age-related impairment of cognitive function. Regulation of mitochondrial function and redox status by IGF-1 is essential to maintain brain function and coordinate hippocampal-dependent spatial learning. While a decline in IGF-1 in the periphery may be beneficial to avert cancer progression, diminished central IGF-1 signaling may mediate, in part, age-related cognitive dysfunction and cognitive pathologies potentially by decreasing mitochondrial function.


2020 ◽  
Vol 34 ◽  
pp. 205873842095014
Author(s):  
Mamdooh Ghoneum ◽  
Shaymaa Abdulmalek ◽  
Deyu Pan

Introduction: Oxidative stress is a key contributor to aging and age-related diseases. In the present study, we examine the protective effects of PFT, a novel kefir product, against age-associated oxidative stress using aged (10-month-old) mice. Methods: Mice were treated with PFT orally at a daily dose of 2 mg/kg body weight over 6 weeks, and antioxidant status, protein oxidation, and lipid peroxidation were studied in the brain, liver, and blood. Results: PFT supplementation significantly reduced the oxidative stress biomarkers malondialdehyde (MDA) and nitric oxide; reversed the reductions in glutathione (GSH) levels, total antioxidant capacity (TAC), and anti-hydroxyl radical (AHR) content; enhanced the antioxidant enzyme activities of glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD); inhibited the liver enzyme levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT); significantly reduced triglyceride (TG), total cholesterol (TC), and low density lipoprotein (LDL) levels; and significantly elevated high density lipoprotein (HDL) levels. Interestingly, PFT supplementation reversed the oxidative changes associated with aging, thus bringing levels to within the limits of the young control mice in the brain, liver, and blood. We also note that PFT affects the redox homeostasis of young mice and that it is corrected post-treatment with PFT. Conclusion: Our findings show the effectiveness of dietary PFT supplementation in modulating age-associated oxidative stress in mice and motivate further studies of PFT’s effects in reducing age-associated disorders where free radicals and oxidative stress are the major cause.


Author(s):  
Jessica R. Andrews-Hanna ◽  
Matthew D. Grilli ◽  
Muireann Irish

The brain’s default network (DN) has received considerable interest in the context of so-called “normal” and pathological aging. Findings have generally been couched in support of a pessimistic view of brain aging, marked by substantial loss of structural brain integrity accompanied by a host of impairments in brain and cognitive function. A critical look at the literature, however, reveals that the standard loss of integrity, loss of function (LILF) view in normal aging may not necessarily hold with respect to the DN and the internally guided functions it supports. Many internally guided processes subserved by the DN are preserved or enhanced in cognitively healthy older adults. Moreover, differences in motivational, contextual, and physiological factors between young and older adults likely influence the extant neuroimaging and cognitive findings. Accordingly, normal aging can be viewed as a series of possibly adaptive cognitive and DN-related alterations that bolster cognitive function and promote socioemotional well-being and stability in a stage of life noted for change. On the other hand, the available evidence reveals strong support for the LILF view of the DN in neurodegenerative disorders, whereby syndromes such as Alzheimer’s disease (AD) and semantic dementia (SD), characterized by progressive atrophy to distinct DN subsystems, display distinct aberrations in autobiographical and semantic cognition. Taken together, these findings call for more naturalistic, age-appropriate, and longitudinal paradigms when investigating neurocognitive changes in aging and to adequately assess and control for differences in non-neural factors that may obscure “true” effects of normal and pathological aging. A shift in the framework with which age-related alterations in internally guided cognition are interpreted may shed important light on the neurocognitive mechanisms differentiating healthy and pathological aging, leading to a more complete picture of the aging brain in all its complexity.


Author(s):  
Mariya Ivanovska ◽  
Zakee Abdi ◽  
Marianna Murdjeva ◽  
Danielle Macedo ◽  
Annabel Maes ◽  
...  

Background: CCL11 (eotaxin) is a chemokine with an important role in allergic conditions. Recent evidence indicates that CCL11 plays a role in brain disorders as well. Aims: This paper reviews the associations between CCL11 and aging, neurodegenerative, neuroinflammatory and neuropsychiatric disorders.Methods: Electronic databases were searched for original articles examining CCL11 in neuropsychiatric disorders.Results: CCL11 is rapidly transported from the blood to the brain through the brain-blood barrier. Age-related increases in CCL11 are associated with cognitive impairments in executive functions, episodic and semantic memory and, therefore, this chemokine was described as an “endogenous cognition deteriorating chemokine” (ECDC) or “accelerated brain-aging chemokine” (ABAC). In schizophrenia, increased CCL11 is not only associated with impairments in cognitive functions, but also with key symptoms including formal thought disorders. Some patients with mood disorders and premenstrual syndrome show increased plasma CCL11 levels. In diseases of old age, CCL11 is associated with lowered neurogenesis and neurodegenerative processes and, as a consequence, increased CCL11 increases risk towards Alzheimer's Disease. Polymorphisms in the CCL11 gene are associated with stroke. Increased CCL11 also plays a role in neuroinflammatory disease including multiple sclerosis. In animal models, neutralization of CCL11 may protect against nigrostriatal neurodegeneration. Increased production of CCL11 may be attenuated by glucocorticoids, minocycline, resveratrol and anti-CCL11 antibodies.Conclusion: Increased CCL11 production during inflammatory conditions may play a role in human disease including age-related cognitive decline, schizophrenia, mood disorders and neurodegenerative disorders. Increased CCL11 production is a new drug target in the treatment and prevention of those disorders.


2021 ◽  
Vol 22 (19) ◽  
pp. 10251
Author(s):  
Vladimir Sukhorukov ◽  
Dmitry Voronkov ◽  
Tatiana Baranich ◽  
Natalia Mudzhiri ◽  
Alina Magnaeva ◽  
...  

Aging is associated with a decline in cognitive function, which can partly be explained by the accumulation of damage to the brain cells over time. Neurons and glia undergo morphological and ultrastructure changes during aging. Over the past several years, it has become evident that at the cellular level, various hallmarks of an aging brain are closely related to mitophagy. The importance of mitochondria quality and quantity control through mitophagy is highlighted by the contribution that defects in mitochondria–autophagy crosstalk make to aging and age-related diseases. In this review, we analyze some of the more recent findings regarding the study of brain aging and neurodegeneration in the context of mitophagy. We discuss the data on the dynamics of selective autophagy in neurons and glial cells during aging and in the course of neurodegeneration, focusing on three mechanisms of mitophagy: non-receptor-mediated mitophagy, receptor-mediated mitophagy, and transcellular mitophagy. We review the role of mitophagy in neuronal/glial homeostasis and in the molecular pathogenesis of neurodegenerative disorders, such as Parkinson’s disease, Alzheimer’s disease, and other disorders. Common mechanisms of aging and neurodegeneration that are related to different mitophagy pathways provide a number of promising targets for potential therapeutic agents.


2020 ◽  
Author(s):  
Young Sung Kim ◽  
Young Ju Won ◽  
Byung Gun Lim ◽  
Too Jae Min ◽  
Yeon-Hwa Kim ◽  
...  

Abstract Background: Hypoxia inhibits the uptake of glutamate (a major neurotransmitter in the brain closely related to cognitive function) into brain cells, and the initial response of cells to cortical hypoxia depends on glutamate. Previous studies have suggested that magnesium may have protective effects against hypoxic injuries. In particular, magnesium L-threonate (MgT) may increase magnesium ion concentrations in the brain better than MgSO4 and improve cognitive function. Methods: We evaluated cell viability under hypoxic conditions in the MgT- and MgSO4-treated human SH-SY5Y neurons, in vivo behavior using the T-maze test following hypoxia in MgT-treated zebrafish, activity of brain mitochondrial dehydrogenase by 2,3,5-triphenyltetrazolium chloride (TTC) staining, and protein expression of the excitatory amino acid transporter (EAAT) 4 glutamate transporter by western blotting. Results: Among the groups treated with hypoxia, cell viability significantly increased when pre-treated with 1 or 10 mM MgT (p = 0.009 and 0.026, respectively) Despite hypoxic insult, MgT-treated zebrafish showed preferences for the red compartment (p= 0.025 for distance and p= 0.007 for frequency of entries), suggesting memory preservation. TTC staining showed reduced cerebral infarction and preserved absorbance in the MgT-treated zebrafish brain after hypoxia (p=0.010 compared to the hypoxia group). In addition, western blot showed upregulation of EAAT4 protein in the MgT treated group. Conclusions: Pre-treatment with MgT attenuated cell death and cerebral infarction due to hypoxia and protected cognitive function in zebrafish. In addition, MgT appeared to modulate expression of the glutamate transporter, EAAT4.


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