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Concept: Aging-associated diseases

251

We developed a new statistical framework to find genetic variants associated with extreme longevity. The method, informed GWAS (iGWAS), takes advantage of knowledge from large studies of age-related disease in order to narrow the search for SNPs associated with longevity. To gain support for our approach, we first show there is an overlap between loci involved in disease and loci associated with extreme longevity. These results indicate that several disease variants may be depleted in centenarians versus the general population. Next, we used iGWAS to harness information from 14 meta-analyses of disease and trait GWAS to identify longevity loci in two studies of long-lived humans. In a standard GWAS analysis, only one locus in these studies is significant (APOE/TOMM40) when controlling the false discovery rate (FDR) at 10%. With iGWAS, we identify eight genetic loci to associate significantly with exceptional human longevity at FDR < 10%. We followed up the eight lead SNPs in independent cohorts, and found replication evidence of four loci and suggestive evidence for one more with exceptional longevity. The loci that replicated (FDR < 5%) included APOE/TOMM40 (associated with Alzheimer's disease), CDKN2B/ANRIL (implicated in the regulation of cellular senescence), ABO (tags the O blood group), and SH2B3/ATXN2 (a signaling gene that extends lifespan in Drosophila and a gene involved in neurological disease). Our results implicate new loci in longevity and reveal a genetic overlap between longevity and age-related diseases and traits, including coronary artery disease and Alzheimer's disease. iGWAS provides a new analytical strategy for uncovering SNPs that influence extreme longevity, and can be applied more broadly to boost power in other studies of complex phenotypes.

Concepts: Alzheimer's disease, Gene, Cancer, Senescence, Atherosclerosis, Coronary artery disease, Gerontology, Aging-associated diseases

142

Cellular senescence prevents the proliferation of cells at risk for neoplastic transformation. However, the altered secretome of senescent cells can promote the growth of the surrounding cancer cells. Although extracellular vesicles (EVs) have emerged as new players in intercellular communication, their role in the function of senescent cell secretome has been largely unexplored. Here, we show that exosome-like small EVs (sEVs) are important mediators of the pro-tumorigenic function of senescent cells. sEV-associated EphA2 secreted from senescent cells binds to ephrin-A1, that is, highly expressed in several types of cancer cells and promotes cell proliferation through EphA2/ephrin-A1 reverse signalling. sEV sorting of EphA2 is increased in senescent cells because of its enhanced phosphorylation resulting from oxidative inactivation of PTP1B phosphatase. Our results demonstrate a novel mechanism of reactive oxygen species (ROS)-regulated cargo sorting into sEVs, which is critical for the potentially deleterious growth-promoting effect of the senescent cell secretome.

Concepts: Gene expression, Cancer, Disease, Senescence, Cell division, Oxidative phosphorylation, Ageing, Aging-associated diseases

96

This review provides the reader with the up-to-date evidence-based basis for prescribing exercise as medicine in the treatment of 26 different diseases: psychiatric diseases (depression, anxiety, stress, schizophrenia); neurological diseases (dementia, Parkinson’s disease, multiple sclerosis); metabolic diseases (obesity, hyperlipidemia, metabolic syndrome, polycystic ovarian syndrome, type 2 diabetes, type 1 diabetes); cardiovascular diseases (hypertension, coronary heart disease, heart failure, cerebral apoplexy, and claudication intermittent); pulmonary diseases (chronic obstructive pulmonary disease, asthma, cystic fibrosis); musculo-skeletal disorders (osteoarthritis, osteoporosis, back pain, rheumatoid arthritis); and cancer. The effect of exercise therapy on disease pathogenesis and symptoms are given and the possible mechanisms of action are discussed. We have interpreted the scientific literature and for each disease, we provide the reader with our best advice regarding the optimal type and dose for prescription of exercise.

Concepts: Osteoporosis, Medicine, Hypertension, Diabetes mellitus type 2, Diabetes mellitus, Obesity, Cystic fibrosis, Aging-associated diseases

60

Vitamin D has multiple roles, including the regulation of bone and calcium homeostasis. Deficiency of 25-hydroxyvitamin D, the major circulating form of vitamin D, is associated with an increased risk of age-related chronic diseases, including Alzheimer’s disease, Parkinson’s disease, cognitive impairment, and cancer. In this study, we utilized Caenorhabditis elegans to examine the mechanism by which vitamin D influences aging. We found that vitamin-D3-induced lifespan extension requires the stress response pathway genes skn-1, ire-1, and xbp-1. Vitamin D3 (D3) induced expression of SKN-1 target genes but not canonical targets of XBP-1. D3 suppressed an important molecular pathology of aging, that of widespread protein insolubility, and prevented toxicity caused by human β-amyloid. Our observation that D3 improves protein homeostasis and slows aging highlights the importance of maintaining appropriate vitamin D serum levels and may explain why such a wide variety of human age-related diseases are associated with vitamin D deficiency.

Concepts: Osteoporosis, Vitamin D, Cancer, Senescence, RNA, Calcium, Vitamins, Aging-associated diseases

48

A growing body of evidence supports a link between androgen deprivation therapy (ADT) and cognitive dysfunction, including Alzheimer disease. However, it is currently unknown whether ADT may contribute to the risk of dementia more broadly.

Concepts: Alzheimer's disease, Neurology, Parkinson's disease, Dementia, Caregiving and dementia, Wandering, Sundowning, Aging-associated diseases

41

Aging is a major driving force underlying dementia, such as that caused by Alzheimer’s disease (AD). While the idea of targeting aging as a therapeutic strategy is not new, it remains unclear how closely aging and age-associated diseases are coupled at the molecular level. Here, we discover a novel molecular link between aging and dementia through the identification of the molecular target for the AD drug candidate J147. J147 was developed using a series of phenotypic screening assays mimicking disease toxicities associated with the aging brain. We have previously demonstrated the therapeutic efficacy of J147 in several mouse models of AD. Here, we identify the mitochondrial α-F1 -ATP synthase (ATP5A) as a target for J147. By targeting ATP synthase, J147 causes an increase in intracellular calcium leading to sustained calcium/calmodulin-dependent protein kinase kinase β (CAMKK2)-dependent activation of the AMPK/mTOR pathway, a canonical longevity mechanism. Accordingly, modulation of mitochondrial processes by J147 prevents age-associated drift of the hippocampal transcriptome and plasma metabolome in mice and extends lifespan in drosophila. Our results link aging and age-associated dementia through ATP synthase, a molecular drug target that can potentially be exploited for the suppression of both. These findings demonstrate that novel screens for new AD drug candidates identify compounds that act on established aging pathways, suggesting an unexpectedly close molecular relationship between the two.

Concepts: Alzheimer's disease, Cancer, Molecular biology, Adenosine triphosphate, Mitochondrion, Aging, Aging-associated diseases, ATP synthase

41

The objective of this research was to update earlier estimates of prevalence rates of single chronic conditions and multiple (>2) chronic conditions (MCC) among the noninstitutionalized, civilian US adult population. Data from the 2012 National Health Interview Survey (NHIS) were used to generate estimates of MCC for US adults and by select demographic characteristics. Approximately half (117 million) of US adults have at least one of the 10 chronic conditions examined (ie, hypertension, coronary heart disease, stroke, diabetes, cancer, arthritis, hepatitis, weak or failing kidneys, current asthma, or chronic obstructive pulmonary disease [COPD]). Furthermore, 1 in 4 adults has MCC.

Concepts: Medicine, Asthma, Hypertension, Heart, Obesity, Heart disease, Chronic obstructive pulmonary disease, Aging-associated diseases

36

OBJECTIVE: This meta-analysis aims to quantitatively synthesize all studies that examine the association between adherence to a Mediterranean diet and risk of stroke, depression, cognitive impairment and Parkinson’s disease. METHODS: Potentially eligible publications were those providing effect estimates of relative risk (RR) for the association between Mediterranean diet and the aforementioned outcomes. Studies were sought in PubMed up to October 31, 2012. Maximally adjusted effect estimates were extracted; separate analyses were performed for high and moderate adherence. RESULTS: 22 eligible studies were included (11 for stroke, nine for depression and eight for cognitive impairment; only one pertained to Parkinson’s disease). High adherence to Mediterranean diet was consistently associated with reduced risk for stroke (RR=0.71, 95%CI: 0.57-0.89), depression (RR=0.68, 95%CI: 0.54-0.86) and cognitive impairment (RR=0.60, 95%CI: 0.43-0.83). Moderate adherence was similarly associated with reduced risk for depression and cognitive impairment, whereas the protective trend concerning stroke was only marginal. Subgroup analyses highlighted the protective actions of high adherence in terms of reduced risk for ischemic stroke, mild cognitive impairment, dementia and particularly Alzheimer’s disease. Meta-regression analysis indicated that the protective effects of Mediterranean diet in stroke prevention seemed more sizeable among males. Concerning depression, the protective effects of high adherence seemed independent of age, whereas the favorable actions of moderate adherence seemed to fade away along with older age. INTERPRETATION: Adherence to a Mediterranean diet may contribute to the prevention of a series of brain diseases; this may be of special value given the aging of Western societies. ANN NEUROL 2013. © 2013 American Neurological Association.

Concepts: Alzheimer's disease, Epidemiology, Brain, Stroke, Neurology, Parkinson's disease, Dementia, Aging-associated diseases

32

BACKGROUND:: Adherence to a Mediterranean diet has been associated with lower risk of various age-related diseases including dementia. Although narrative reviews have been published, no systematic review has synthesized studies on the association between Mediterranean diet adherence and cognitive function or dementia. METHODS:: We conducted a systematic review of 11 electronic databases (including Medline) of published articles up to January 2012. Reference lists, selected journal contents, and relevant websites were also searched. Study selection, data extraction, and quality assessment were performed independently by two reviewers using predefined criteria. Studies were included if they examined the association between a Mediterranean diet adherence score and cognitive function or dementia. RESULTS:: Twelve eligible papers (11 observational studies and one randomized controlled trial) were identified, describing seven unique cohorts. Despite methodological heterogeneity and limited statistical power in some studies, there was a reasonably consistent pattern of associations. Higher adherence to Mediterranean diet was associated with better cognitive function, lower rates of cognitive decline, and reduced risk of Alzheimer disease in nine out of 12 studies, whereas results for mild cognitive impairment were inconsistent. CONCLUSIONS:: Published studies suggest that greater adherence to Mediterranean diet is associated with slower cognitive decline and lower risk of developing Alzheimer disease. Further studies would be useful to clarify the association with mild cognitive impairment and vascular dementia. Long-term randomized controlled trials promoting a Mediterranean diet may help establish whether improved adherence helps to prevent or delay the onset of Alzheimer disease and dementia.

Concepts: Alzheimer's disease, Experimental design, Epidemiology, Clinical trial, Randomized controlled trial, Cognition, Pharmaceutical industry, Aging-associated diseases

26

Telomere shortening in arteries could lead to telomere uncapping and cellular senescence, which in turn could promote the development of hypertension.

Concepts: Senescence, Myocardial infarction, Atherosclerosis, Blood pressure, Telomerase, Telomere, Aging-associated diseases, Immortality