Chronic stress as a risk factor for Alzheimer’s disease

2014 ◽  
Vol 25 (6) ◽  
Author(s):  
Alberto Machado ◽  
Antonio J. Herrera ◽  
Rocío M. de Pablos ◽  
Ana María Espinosa-Oliva ◽  
Manuel Sarmiento ◽  
...  

AbstractThis review aims to point out that chronic stress is able to accelerate the appearance of Alzheimer’s disease (AD), proposing the former as a risk factor for the latter. Firstly, in the introduction we describe some human epidemiological studies pointing out the possibility that chronic stress could increase the incidence, or the rate of appearance of AD. Afterwards, we try to justify these epidemiological results with some experimental data. We have reviewed the experiments studying the effect of various stressors on different features in AD animal models. Moreover, we also point out the data obtained on the effect of chronic stress on some processes that are known to be involved in AD, such as inflammation and glucose metabolism. Later, we relate some of the processes known to be involved in aging and AD, such as accumulation of β-amyloid, TAU hyperphosphorylation, oxidative stress and impairement of mitochondrial function, emphasizing how they are affected by chronic stress/glucocorticoids and comparing with the description made for these processes in AD. All these data support the idea that chronic stress could be considered a risk factor for AD.

Author(s):  
Luigi Attademo ◽  
Francesco Bernardini

As a global problem that has increasingly been causing worldwide concern, air pollution poses a significant and serious environmental risk to health. Risks of cardiovascular and respiratory diseases, as well as various types of cancer, have been consistently associated with the exposure to air pollutants. More recently, various studies have also shown that the central nervous system is also attacked by air pollution. Air pollution appears to be strongly associated with a higher risk of cognitive defects, neurodevelopmental (e.g., schizophrenia) and neurodegenerative (e.g., Alzheimer’s disease) disorders. Subjects with schizophrenia, as well as subjects with Alzheimer’s disease, experience a variety of neuropsychological deficits and cognitive impairments. This determines an adverse effect on social and professional functioning, and it contributes to the long-term disease burden. However, no final conclusions have been drawn on the matter of the direct relationship between schizophrenia and Alzheimer’s disease. In recent years, the topic of urbanicity and mental health has become increasingly important. Urban exposure to environmental toxins and pollution is currently described as a reliable risk factor for schizophrenia and other psychoses, and it has been demonstrated more and more how exposure to air pollutants is associated with increased risk of dementia. Pathways by which air pollution can target and damage the brain, leading to an increased risk for developing schizophrenia and Alzheimer’s disease, are multiple and complex. Results from epidemiological studies suggest potential associations, but are still insufficient to confirm causality. Further studies are needed in order to verify this hypothesis. And if confirmed, the clinical implications could be of substantial relevance for both public and mental health.


2020 ◽  
Vol 6 (33) ◽  
pp. eabb9036
Author(s):  
Bradlee L. Heckmann ◽  
Brett J. W. Teubner ◽  
Emilio Boada-Romero ◽  
Bart Tummers ◽  
Clifford Guy ◽  
...  

Noncanonical functions of autophagy proteins have been implicated in neurodegenerative conditions, including Alzheimer’s disease (AD). The WD domain of the autophagy protein Atg16L is dispensable for canonical autophagy but required for its noncanonical functions. Two-year-old mice lacking this domain presented with robust β-amyloid (Aβ) pathology, tau hyperphosphorylation, reactive microgliosis, pervasive neurodegeneration, and severe behavioral and memory deficiencies, consistent with human disease. Mechanistically, we found this WD domain was required for the recycling of Aβ receptors in primary microglia. Pharmacologic suppression of neuroinflammation reversed established memory impairment and markers of disease pathology in this novel AD model. Therefore, loss of the Atg16L WD domain drives spontaneous AD in mice, and inhibition of neuroinflammation is a potential therapeutic approach for treating neurodegeneration and memory loss. A decline in expression of ATG16L in the brains of human patients with AD suggests the possibility that a similar mechanism may contribute in human disease.


Cancers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3842
Author(s):  
Harvey R. Fernandez ◽  
Ashima Varma ◽  
Sarah A. Flowers ◽  
George William Rebeck

Cancer related cognitive impairment (CRCI) is a serious impairment to maintaining quality of life in cancer survivors. Cancer chemotherapy contributes to this condition through several potential mechanisms, including damage to the blood brain barrier, increases in oxidative stress and inflammation in the brain, and impaired neurogenesis, each of which lead to neuronal dysfunction. A genetic predisposition to CRCI is the E4 allele of the Apolipoprotein E gene (APOE), which is also the strongest genetic risk factor for Alzheimer’s disease. In normal brains, APOE performs essential lipid transport functions. The APOE4 isoform has been linked to altered lipid binding, increased oxidative stress and inflammation, reduced turnover of neural progenitor cells, and impairment of the blood brain barrier. As chemotherapy also affects these processes, the influence of APOE4 on CRCI takes on great significance. This review outlines the main areas where APOE genotype could play a role in CRCI. Potential therapeutics based on APOE biology could mitigate these detrimental cognitive effects for those receiving chemotherapy, emphasizing that the APOE genotype could help in developing personalized cancer treatment regimens.


Nutrients ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 3215
Author(s):  
Muhammad Luqman Nasaruddin ◽  
Syarifah Aisyah Syed Abd Halim ◽  
Mohd Amir Kamaruzzaman

We examined the evidence for intermittent fasting (IF) as a preventative tool to influence β-amyloid in animal models of Alzheimer’s disease (AD). A Scopus, Ovid, PubMed, and Web of Science (WoS), search yielded 29 results using the keywords “amyloid beta”, “intermittent fasting”, “intermittent caloric restriction”, “alternate day fasting”, “modified alternate-day fasting”, “time-restricted feeding”, “Ramadan fast”, “intermittent calori* restriction”, “intermittent restrictive diet”, and “Alzheimer*”. Five research articles addressed directly the effects of intermittent fasting on β-amyloid levels in animal models of AD: alternate day fasting (ADF) and time-restricted feeding (TRF) methods were incorporated in these studies. The study designs were found to be heterogeneous. Variations in the levels of β-amyloid peptides or plaque in either the hippocampus, cortical areas, or both in animals following dietary intervention were observed as compared to the ad libitum group. Non-significant changes were observed in three studies, while two studies interestingly demonstrated amelioration and reduction in β-amyloid levels. Given the conflicting results obtained from this study, significant care has to be taken into consideration before the protocol can be applied as a preventative approach to treat Alzheimer’s disease. Longitudinal research is warranted to fully grasp how dietary habits can help alleviate the disease either through upstream or downstream of AD pathology.


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