Assessment and risk prediction of frailty using texture-based muscle ultrasound image analysis and machine learning techniques

The purpose of this study was to evaluate texture-based muscle ultrasound image analysis for the assessment and risk prediction of frailty phenotype. This retrospective study of prospectively acquired data included 101 participants who underwent ultrasound scanning of the anterior thigh. Participants were subdivided according to frailty phenotype and were followed up for two years. Primary and secondary outcome measures were death and comorbidity, respectively. Forty-three texture features were computed from the rectus femoris and the vastus intermedius muscles using statistical methods. Model performance was evaluated by computing the area under the receiver operating characteristic curve (AUC) while outcome prediction was evaluated using regression analysis. Models developed achieved a moderate to good AUC (0.67 ≤ AUC ≤ 0.79) for categorizing frailty. The stepwise multiple logistic regression analysis demonstrated that they correctly classified 70-87% of the cases. The models were associated with increased comorbidity (0.01 ≤ p ≤ 0.18) and were predictive of death for pre-frail and frail participants (0.001 ≤ p ≤ 0.016). In conclusion, texture analysis can be useful to identify frailty and assess risk prediction (i.e. mortality) using texture features extracted from muscle ultrasound images in combination with a machine learning approach.

Altered Lipid Moieties and Carbonyls in a Wistar Rat Dietary Model of Subclinical Fatty Liver: Potential Sex-Specific Biomarkers of Early Fatty Liver Disease?

Non-alcoholic fatty liver disease (NAFLD) is a condition in which excess fat builds up in the liver. To date, there is a lack of knowledge about the subtype of lipid structures affected in the early stages of NAFLD. The aim of this study was to analyze serum and liver lipid moieties, specifically unsaturations and carbonyls, by nuclear magnetic resonance (NMR) in a subclinical Wistar rat model of NAFLD for detecting early alterations and potential sex dimorphisms. Twelve weeks of a high-fat diet (HFD) induced fat accumulation in the liver to a similar extent in male and female Wistar rats. In addition to total liver fat accumulation, Wistar rats showed a shift in lipid subtype composition. HFD rats displayed increased lipid carbonyls in both liver and serum, and decreased in unsaturated fatty acids (UFAs) and polyunsaturated fatty acids (PUFAs), with a much stronger effect in male than female animals. Our results revealed that the change in fat was not only quantitative but also qualitative, with dramatic shifts in relevant lipid structures. Finally, we compared the results found in Wistar rats with an analysis in a human patient cohort of extreme obesity. For the first time to our knowledge, lipid carbonyl levels and lipoproteins profiles were analyzed in the context of subclinical NAFLD. The association found between lipid carbonyls and alanine aminotransferase (ALT) in a human cohort of extremely obese individuals further supports the potential role of lipid moieties as biomarkers of early NAFLD.

The Role of Extracellular Vesicles in Aging and Disease

Cells are exposed to various internal and external factors that can cause damage over time [...].

The Potential Use of Mitochondrial Extracellular Vesicles as Biomarkers or Therapeutical Tools

The mitochondria play a crucial role in cellular metabolism, reactive oxygen species (ROS) production, and apoptosis. Aberrant mitochondria can cause severe damage to the cells, which have established a tight quality control for the mitochondria. This process avoids the accumulation of damaged mitochondria and can lead to the release of mitochondrial constituents to the extracellular milieu through mitochondrial extracellular vesicles (MitoEVs). These MitoEVs carry mtDNA, rRNA, tRNA, and protein complexes of the respiratory chain, and the largest MitoEVs can even transport whole mitochondria. Macrophages ultimately engulf these MitoEVs to undergo outsourced mitophagy. Recently, it has been reported that MitoEVs can also contain healthy mitochondria, whose function seems to be the rescue of stressed cells by restoring the loss of mitochondrial function. This mitochondrial transfer has opened the field of their use as potential disease biomarkers and therapeutic tools. This review describes this new EVs-mediated transfer of the mitochondria and the current application of MitoEVs in the clinical environment.

Plasma acylcarnitines and gut-derived aromatic amino acids as sex-specific hub metabolites of the human aging metabolome

Aging biology entails a cell/tissue deregulated metabolism that affects all levels of biological organization. Therefore, the application of "omic" techniques that are closer to phenotype, such as metabolomics, to the study of the aging process should be a turning point in the definition of cellular processes involved. The main objective of the present study was to describe the changes in plasma metabolome associated with biological aging and the role of sex in the metabolic regulation during aging. A high-throughput untargeted metabolomic analysis was applied in plasma samples to detect hub metabolites and biomarkers of aging incorporating a sex/gender perspective. A cohort of 1030 healthy human adults (45.9% females, and 54.1% males) from 50 to 98 years of age was used. Results were validated using two independent cohorts (1: n = 146, 53% females, 30-100 years old; 2: n = 68, 70% females, 19-107 years old). Metabolites related to lipid and aromatic amino acid (AAA) metabolisms arose as the main metabolic pathways affected by age, with a high influence of sex. Globally, we describe changes in bioenergetic pathways that point to a decrease in mitochondrial β-oxidation and an accumulation of unsaturated fatty acids and acylcarnitines that could be responsible for the increment of oxidative damage and inflammation characteristic of this physiological process. Furthermore, we describe for the first time the importance of gut-derived AAA catabolites in the aging process describing novel biomarkers that could contribute to better understand this physiological process but also age-related diseases.

Small extracellular vesicles from senescent stem cells trigger adaptive mechanisms in young stem cells by increasing antioxidant enzyme expression

Extracellular vesicles' biogenesis, shedding, and uptake are redox-sensitive. Indeed, oxidative stress conditions influence extracellular vesicles' release and content, which can modulate the redox status of the receiving cells. In this study, we aimed to assess the effect of extracellular vesicles from human dental pulp stem cells cultured under 21% O₂ (senescent stem cells) on human dental pulp stem cells cultured under 3% O₂ (young stem cells). Extracellular vesicles were isolated by ultracentrifugation from senescent stem cells and prepared for the treatment of young stem cells at a final concentration of 10 μg/mL. Cells were analyzed for antioxidant gene expression, mitochondrial bioenergetic parameters, ROS production, culture kinetics, and apoptosis. The results show that extracellular vesicles from senescent stem cells induce overexpression of antioxidant genes (MnSOD, CAT, and GPx) in young stem cells, which show an increased non-mitochondrial oxygen consumption, accompanied by reduced maximal respiration and spare respiratory capacity without altering mitochondrial membrane potential. This is accompanied by improved cell proliferation, viability, and migration rates and a reduction of apoptosis. In conclusion, extracellular vesicles from senescent stem cells trigger an adaptive response in young stem cells which improves their antioxidant defenses and their proliferation, migration, and survival rates. This suggests that extracellular vesicles can modulate the cells' microenvironment and the balance between proliferation and senescence.

Effect of Familial Longevity on Frailty and Sarcopenia: A Case-Control Study

Familial longevity confers advantages in terms of health, functionality, and longevity. We sought to assess potential differences in frailty and sarcopenia in older adults according to a parental history of extraordinary longevity. A total of 176 community-dwelling subjects aged 65-80 years were recruited in this observational case-control study, pair-matched 1:1 for gender, age, and place of birth and residence: 88 centenarians' offspring (case group) and 88 non-centenarians' offspring (control group). The main variables were frailty and sarcopenia based on Fried's phenotype and the European Working Group on Sarcopenia in Older People (EWGSOP) definitions, respectively. Sociodemographics, comorbidities, clinical and functional variables, the presence of geriatric syndromes, and laboratory parameters were also collected. Related sample tests were applied, and conditional logistic regression was performed. Cases had a higher percentage of robust patients (31.8% vs. 15.9%), lower percentages of frailty (9.1% vs. 21.6%) and pre-frailty (59.1% vs. 62.5%) (p = 0.001), and lower levels of IL-6 (p = 0.044) than controls. The robust adjusted OR for cases was 3.00 (95% CI = 1.06-8.47, p = 0.038). No significant differences in muscle mass were found. Familial longevity was also associated with less obesity, insomnia, pain, and polypharmacy and a higher education level and total and low-density lipoprotein cholesterol. The results suggest an inherited genetic component in the frailty phenotype, while the sarcopenia association with familial longevity remains challenging.

Therapeutic Potential of Extracellular Vesicles in Aging and Age-Related Diseases

Aging is associated with an alteration of intercellular communication. These changes in the extracellular environment contribute to the aging phenotype and have been linked to different aging-related diseases. Extracellular vesicles (EVs) are factors that mediate the transmission of signaling molecules between cells. In the aging field, these EVs have been shown to regulate important aging processes, such as oxidative stress or senescence, both in vivo and in vitro. EVs from healthy cells, particularly those coming from stem cells (SCs), have been described as potential effectors of the regenerative potential of SCs. Many studies with different animal models have shown promising results in the field of regenerative medicine. EVs are now viewed as a potential cell-free therapy for tissue damage and several diseases. Here we propose EVs as regulators of the aging process, with an important role in tissue regeneration and a raising therapy for age-related diseases.

Genistein effect on cognition in prodromal Alzheimer's disease patients. The GENIAL clinical trial

BACKGROUND

Delaying the transition from minimal cognitive impairment to Alzheimer's dementia is a major concern in Alzheimer's disease (AD) therapeutics. Pathological signs of AD occur years before the onset of clinical dementia. Thus, long-term therapeutic approaches, with safe, minimally invasive, and yet effective substances are recommended. There is a need to develop new drugs to delay Alzheimer's dementia. We have taken a nutritional supplement approach with genistein, a chemically defined polyphenol that acts by multimodal specific mechanisms. Our group previously showed that genistein supplementation is effective to treat the double transgenic (APP/PS1) AD animal model.

METHODS

In this double-blind, placebo-controlled, bicentric clinical trial, we evaluated the effect of daily oral supplementation with 120 mg of genistein for 12 months on 24 prodromal Alzheimer's disease patients. The amyloid-beta deposition was analyzed using 18F-flutemetamol uptake. We used a battery of validated neurocognitive tests: Mini-Mental State Exam (MMSE), Memory Alteration Test (M@T), Clock Drawing Test, Complutense Verbal Learning Test (TAVEC), Barcelona Test-Revised (TBR), and Rey Complex Figure Test.

RESULTS

We report that genistein treatment results in a significant improvement in two of the tests used (dichotomized direct TAVEC, p = 0.031; dichotomized delayed Centil REY copy p = 0.002 and a tendency to improve in all the rest of them. The amyloid-beta deposition analysis showed that genistein-treated patients did not increase their uptake in the anterior cingulate gyrus after treatment (p = 0.878), while placebo-treated did increase it (p = 0.036). We did not observe significant changes in other brain areas studied.

CONCLUSIONS

This study shows that genistein may have a role in therapeutics to delay the onset of Alzheimer's dementia in patients with prodromal Alzheimer's disease. These encouraging results indicate that this should be followed up by a new study with more patients to further validate the conclusion that arises from this study.

TRIAL REGISTRATION

NCT01982578, registered on November 13, 2013.

Small extracellular vesicles from young adipose-derived stem cells prevent frailty, improve health span, and decrease epigenetic age in old mice

Aging is associated with an increased risk of frailty, disability, and mortality. Strategies to delay the degenerative changes associated with aging and frailty are particularly interesting. We treated old animals with small extracellular vesicles (sEVs) derived from adipose mesenchymal stem cells (ADSCs) of young animals, and we found an improvement in several parameters usually altered with aging, such as motor coordination, grip strength, fatigue resistance, fur regeneration, and renal function, as well as an important decrease in frailty. ADSC-sEVs induced proregenerative effects and a decrease in oxidative stress, inflammation, and senescence markers in muscle and kidney. Moreover, predicted epigenetic age was lower in tissues of old mice treated with ADSC-sEVs and their metabolome changed to a youth-like pattern. Last, we gained some insight into the microRNAs contained in sEVs that might be responsible for the observed effects. We propose that young sEV treatment can promote healthy aging.

The Usefulness of Radiomics Methodology for Developing Descriptive and Prognostic Image-Based Phenotyping in the Aging Population: Results From a Small Feasibility Study

Background: Radiomics is an emerging field that translates medical images into quantitative data to enable phenotypic profiling of human disease. In this retrospective study, we asked whether it is possible to use image-based phenotyping to describe and determine prognostic factors in the aging population.

Methods: A radiomic frailty cohort with 101 patients was included in the analysis (65 ± 15 years, 55 men). A total of 44 texture features were extracted from the segmented muscle area of the ultrasound images of the anterior thigh. Univariate and multivariate analyses were performed to assess the image data sets and clinical data.

Results: Our results showed that the heterogeneity of muscle was associated with an increased incidence of hearing impairment, stroke, myocardial infarction, dementia/memory loss, and falls in the following two years. Regression analysis revealed a muscle radiomic model with 87.1% correct predictive value with good sensitivity and moderate specificity (p = 0.001).

Conclusion: It is possible to develop and identify image-based phenotypes in the elderly population. The muscle radiomic model needs to further be validated. Future studies correlated with biological data (genomics, transcriptomics, metabolomics, etc.) will give further insights into the biological basis and molecular processes of the developed radiomic model.

Functional transcriptomic analysis of centenarians' offspring reveals a specific genetic footprint that may explain that they are less frail than age-matched non-centenarians' offspring

Centenarians exhibit extreme longevity and compression of morbidity and display a unique genetic signature. Centenarians' offspring seem to inherit centenarians' compression of morbidity, as measured by lower rates of age-related pathologies. We aimed to ascertain whether centenarians' offspring are less frail and whether they are endowed with a "centenarian genetic footprint" in a case-control study, matched 1:1 for gender, age ±5 years, and place of birth and residence. Cases must have a living parent aged 97 years or older, aged 65-80 years, community-dwelling, not suffering from a terminal illness, or less than 6 months of life expectancy. Controls had to meet the same criteria as cases except for the age of death of their parents (not older than 89 years). Centenarians were individuals 97 years or older. Frailty phenotype was determined by Fried's Criteria. We collected plasma and peripheral blood mononuclear cells from 63 centenarians, 88 centenarians' offspring, and 88 non-centenarians' offspring. miRNA expression and mRNA profiles were performed by the GeneChip miRNA 4.0 Array (Thermo Fisher Scientific) and GeneChip Clariom S Human Array (Thermo Fisher Scientific), respectively. We found a lower incidence of frailty among centenarians' offspring when compared to their contemporaries' non- centenarians' offspring (p <0.01). Both miRNA and mRNA expression patterns in centenarians' offspring were more like those of centenarians than those of non-centenarians' offspring (p <0.01). in conclusion, centenarians' offspring are less frail than age-matched non-centenarians' offspring, and this may be explained by their unique genetic endowment.

The Contribution of Extracellular Vesicles From Senescent Endothelial and Vascular Smooth Muscle Cells to Vascular Calcification

Vascular calcification is an irreversible pathological process associated with a loss of vascular wall function. This process occurs as a result of aging and age-related diseases, such as cardiovascular and chronic kidney diseases, and leads to comorbidities. During these age-related diseases, the endothelium accumulates senescent cells, which stimulate calcification in vascular smooth muscle cells. Currently, vascular calcification is a silent pathology, and there are no early diagnostic tools. Therefore, by the time vascular calcification is diagnosed, it is usually untreatable. Some mediators, such as oxidative stress, inflammation, and extracellular vesicles, are inducers and promoters of vascular calcification. They play a crucial role during vascular generation and the progression of vascular calcification. Extracellular vesicles, mainly derived from injured endothelial cells that have acquired a senescent phenotype, contribute to calcification in a manner mostly dependent on two factors: (1) the number of extracellular vesicles released, and (2) their cargo. In this review, we present state-of-the-art knowledge on the composition and functions of extracellular vesicles involved in the generation and progression of vascular calcification.

The multimodal action of genistein in Alzheimer's and other age-related diseases

Genistein is a phytoestrogen that, due to its structural similarity with estrogen, can both mimic and antagonize estrogen effects. Early analysis proved that at high concentrations, genistein inhibits breast cancer cell proliferation, thereby suggesting an anticancer activity. Since then, many discoveries have identified the genistein mechanism of action, including cell cycle arrest, apoptosis induction, as well as angiogenesis, and metastasis inhibition. In this review, we aim to discuss the multimodal action of genistein as an antioxidant, anti-inflammatory, anti-amyloid β, and autophagy promoter, which could be responsible for the genistein beneficial effect on Alzheimer's. Furthermore, we pinpoint the main signal transduction pathways that are known to be modulated by genistein. Genistein has thus several beneficial effects in several diseases, many of them associated with age, such as the above mentioned Alzheimer disease. Indeed, the beneficial effects of genistein for health promotion depend on each multimodality. In the context of geroscience, genistein has promising beneficial effects due to its multimodal action to treat age associated-diseases.

Blood DNA methylation patterns in older adults with evolving dementia

Dementia and cognitive disorders are major aging-associated pathologies. The prevalence and severity of these conditions are influenced by both genetic and environmental factors. Reflecting this, epigenetic alterations have been associated with each of these processes, especially at the level of DNA methylation, and such changes may help explain the observed interindividual variability in the development of the 2 pathologies. However, the importance of epigenetic alterations in explaining their etiology is unclear because little is known about the timing of when they appear. Here, using Illumina MethylationEPIC arrays, we have longitudinally analyzed the peripheral blood methylomes of cognitively healthy older adults (>70 year), some of whom went on to develop dementia while others stayed healthy. We have characterized 34 individuals at the prediagnosis stage and at a 4-year follow-up in the postdiagnosis stage (total n = 68). Our results show multiple DNA methylation alterations linked to dementia status, particularly at the level of differentially methylated regions. These loci are associated with several dementia-related genes, including PON1, AP2A2, MAGI2, POT1, ITGAX, PACSIN1, SLC2A8, and EIF4E. We also provide validation of the previously reported epigenetic alteration of HOXB6 and PM20D1. Importantly, we show that most of these regions are already altered in the prediagnosis stage of individuals who go on to develop dementia. In conclusion, our observations suggest that dementia-associated epigenetic patterns that have specific biological features are already present before diagnosis, and thus may be important in the design of epigenetic biomarkers for disease detection based on peripheral tissues.

Lifelong soya consumption in males does not increase lifespan but increases health span under a metabolic stress such as type 2 diabetes mellitus

Soya consumption can decrease oxidative stress in animal models. Moreover, phytoestrogens such as genistein, present in soya, can mimic some of the beneficial effects of estrogens and are devoid of significant side effects, such as cancer. In this study, we have performed a controlled lifelong study with male OF1 mice that consumed either a soya-free diet or a soya-rich diet. We show that, although we found an increase in the expression and activity of antioxidant enzymes in soya-consuming mice, it did not increase lifespan. We reasoned that the soya diet could not increase lifespan in a very healthy population, but perhaps it could extend health span in stressed animals such as type 2 diabetic Goto Kakizaki (GK) rats. Indeed, this was the case: we found that male GK rats consuming a soya-rich diet developed the disease at a lower rate and, therefore, lived longer than soya-free diet-consuming rats.

Diagnostic Performance of Muscle Echo Intensity and Fractal Dimension for the Detection of Frailty Phenotype

To determine the relationship between muscle echo intensity (EI) and fractal dimension (FD), and the diagnostic performance of both ultrasound parameters for the identification of frailty phenotype. A retrospective interpretation of ultrasound scans from a previous cohort (November 2014-February 2015) was performed. The sample included healthy participants <60 years old, and participants ≥60 divided into robust, pre-frail, and frail groups according to Fried frailty criteria. A region of interest of the rectus femoris from the ultrasound scan was segmented, and histogram function was applied to obtain EI. For fractal analysis, images were processed using two-dimensional box-counting techniques to calculate FD. Statistical analyses were performed with diagnostic performance tests. A total of 102 participants (mean age 63 ± 16, 57 men) were evaluated. Muscle fractal dimension correlated with EI (r = .38, p < .01) and showed different pattern in the scatter plots when participants were grouped by non-frail (control + robust) and frail (pre-frail + frail). The diagnostic accuracy for EI to categorize frailty was of 0.69 (95%CI: 0.59-0.78, p = .001), with high intra-rater (ICC: 0.98, 95%CI: 0.98-0.99); p < .001) and inter-rater (ICC: 0.89, 95%CI: 0.75-0.95; p < .001) reliability and low measurement error for both parameters (EI: -0.18, LOA95%: -10.8 to 10.5; FD: 0.00, LOA95%: -0.09 to 0.10) in arbitrary units. The ROC curve combining both parameters was not better than EI alone (p = .18). Muscle FD correlated with EI and showed different patterns according to frailty phenotype, with EI outperforming FD as a possible diagnostic tool for frailty.

Lipid peroxidation as measured by chromatographic determination of malondialdehyde. Human plasma reference values in health and disease

Free radicals and oxidants are involved in physiological signaling pathways, although an imbalance between pro-oxidant and anti-oxidant systems in favor of the former leads to major biomolecular damage. This is the so-called oxidative stress, a complex process that affects us all and is responsible for the development of many diseases. Lipids are very sensitive to oxidant attack and to-date, malondialdehyde (MDA), 4-hydroxy-2-nonenal (4-HNE) and F2-isoprostane are the main biomarkers for lipid peroxidation assessment. They all derive from polyunsaturated fatty acids (PUFAs) either by enzyme-catalyzed reactions (physiological) or by non-enzyme reactions (pathological). The profile of PUFAs present in the tissue will determine the proportion of each biomarker. In this review we aim to discuss the proper method for MDA determination using HPLC. We also offer reference MDA values in humans in physiological and pathological conditions.

Importance of stem cell culture conditions for their derived extracellular vesicles therapeutic effect

Stem cell-derived extracellular vesicles (EVs) could be enhanced by modifying specific in vitro parameters when culturing their originating stem cells. Controlling stem cell growth conditions with physical properties, oxygen tension and media preconditioning with soluble factors may influence EVs biogenesis and EVs biological function as well. Unfortunately, many misconceptions and methodological issues have hampered the progress in understanding the biological properties of EVs. In this review we will first discuss the major concerns involved in a suitable EVs production from stem cell culture. Then, we will describe the current techniques for EV isolation, focusing on their advantages and disadvantages, as well as their impact on EVs yield, recovery and functionality. Standardization of the methodology is a prerequisite to compare, to validate and to improve the reliability and credibility of all the different findings reported for the development of EV-based therapeutics.

Targeting Alzheimer's disease with multimodal polypeptide-based nanoconjugates

Alzheimer's disease (AD), the most prevalent form of dementia, remains incurable mainly due to our failings in the search for effective pharmacological strategies. Here, we describe the development of targeted multimodal polypeptide-based nanoconjugates as potential AD treatments. Treatment with polypeptide nanoconjugates bearing propargylamine moieties and bisdemethoxycurcumin or genistein afforded neuroprotection and displayed neurotrophic effects, as evidenced by an increase in dendritic density of pyramidal neurons in organotypic hippocampal culture. The additional conjugation of the Angiopep-2 targeting moiety enhanced nanoconjugate passage through the blood-brain barrier and modulated brain distribution with nanoconjugate accumulation in neurogenic areas, including the olfactory bulb. Nanoconjugate treatment effectively reduced neurotoxic β amyloid aggregate levels and rescued impairments to olfactory memory and object recognition in APP/PS1 transgenic AD model mice. Overall, this study provides a description of a targeted multimodal polyglutamate-based nanoconjugate with neuroprotective and neurotrophic potential for AD treatment.

Moderate Red Wine Consumption Increases the Expression of Longevity-Associated Genes in Controlled Human Populations and Extends Lifespan in Drosophila melanogaster

The beneficial effects of moderate red wine consumption on cardiovascular health are well known. The composition of red wine includes several compounds, such as the phytoestrogen resveratrol, that exert these beneficial effects, although not all the mechanisms by which they act are known. Our aim was to study the effect of red wine consumption on longevity-related genes in controlled human populations, such as cloistered nuns. We found that the expression of catalase, manganese-superoxide dismutase, Sirt1, and p53 was increased in peripheral blood mononuclear cells after 14 days of moderate red wine consumption. This increase was accompanied by an enhanced metabolic wellness: fatty acids, cholesterol, branched chain amino acids (isoleucine and leucine), ketone bodies (acetoacetate), bacterial co-metabolites (trimethylamine), and cellular antioxidants (taurine) contributed to a change in metabolic profile after moderate red wine consumption by the nuns. No serious unwanted side effects were observed. Finally, we tested the effect of moderate red wine consumption on longevity in a controlled animal population, such as D. melanogaster, and found that it increased average life span by 7%. In conclusion, moderate red wine consumption increases the expression of key longevity-related genes and improves metabolic health in humans and increases longevity in flies.

Methionine transsulfuration pathway is upregulated in long-lived humans

Available evidences point to methionine metabolism as a key target to study the molecular adaptive mechanisms underlying differences in longevity. The plasma methionine metabolic profile was determined using a LC-MS/MS platform to systematically define specific phenotypic patterns associated with genotypes of human extreme longevity (centenarians). Our findings demonstrate the presence of a specific plasma profile associated with human longevity characterized by an enhanced transsulfuration pathway and tricarboxylic acid (TCA) cycle intermediates, as well as a reduced content of specific amino acids. Furthermore, our work reveals that centenarians maintain a strongly correlated methionine metabolism, suggesting an improved network integrity, homeostasis and more tightly regulated metabolism. We have discovered a particular methionine signature related to the condition of extreme longevity, allowing the identification of potential mechanisms and biomarkers of healthy aging.

Extracellular Vesicles from Healthy Cells Improves Cell Function and Stemness in Premature Senescent Stem Cells by miR-302b and HIF-1α Activation

Aging is accompanied by the accumulation of senescent cells that alter intercellular communication, thereby impairing tissue homeostasis and reducing organ regenerative potential. Recently, the administration of mesenchymal stem cells (MSC)-derived extracellular vesicles has proven to be more effective and less challenging than current stem cell-based therapies. Extracellular vesicles (EVs) contain a cell-specific cargo of proteins, lipids and nucleic acids that are released and taken up by probably all cell types, thereby inducing functional changes via the horizontal transfer of their cargo. Here, we describe the beneficial properties of extracellular vesicles derived from non-senescent MSC, cultured in a low physiological oxygen tension (3%) microenvironment into prematurely senescent MSC, cultured in a hyperoxic ambient (usual oxygen culture conditions, i.e., 21%). We observed that senescent MCS, treated with EVs from non-senescent MCS, showed reduced SA-β-galactosidase activity levels and pluripotency factor (OCT4, SOX2, KLF4 and cMYC, or OSKM) overexpression and increased glycolysis, as well as reduced oxidative phosphorylation (OXPHOS). Moreover, these EVs’ cargo induced the upregulation of miR-302b and HIF-1α levels in the target cells. We propose that miR-302b triggered HIF-1α upregulation, which in turn activated different pathways to delay premature senescence, improve stemness and switch energetic metabolism towards glycolysis. Taken together, we suggest that EVs could be a powerful tool to restore altered intercellular communication and improve stem cell function and stemness, thus delaying stem cell exhaustion in aging.

BCL-xL, a Mitochondrial Protein Involved in Successful Aging: From C. elegans to Human Centenarians

B-Cell Lymphoma-extra-large (BCL-xL) is involved in longevity and successful aging, which indicates a role for BCL-xL in cell survival pathway regulation. Beyond its well described role as an inhibitor of apoptosis by preventing cytochrome c release, BCL-xL has also been related, indirectly, to autophagy and senescence pathways. Although in these latter cases, BCL-xL has dual roles, either activating or inhibiting, depending on the cell type and the specific conditions. Taken together, all these findings suggest a precise mechanism of action for BCL-xL, able to regulate the crosstalk between apoptosis, autophagy, and senescence, thus promoting cell survival or cell death. All three pathways can be both beneficial or detrimental depending on the circumstances. Thus, targeting BCL-xL would in turn be a "double-edge sword" and therefore, additional studies are needed to better comprehend this dual and apparently contradictory role of BCL-XL in longevity.

Relation Between Genetic Factors and Frailty in Older Adults

OBJECTIVES

Frailty is a geriatric syndrome that identifies individuals at higher risk of disability, institutionalization, and death. We previously reported that frailty is related to oxidative stress and cognitive impairment-related biomarkers. The aim of this study was to determine whether frailty is associated with genetic variants.

DESIGN

Longitudinal population-based cohort of 2488 community-dwelling people from Toledo, Spain, aged 65 years or older.

SETTING AND PARTICIPANTS

We obtained blood samples from 78 individuals with frailty and 74 nonfrail individuals who were nonfrail (according to Fried criteria) from the Toledo Study of Healthy Ageing and extracted DNA using the Chemagic DNA blood kit.

MEASURES

Sample genotyping was carried out by means of Axiom Exome 319 Genotyping Array (Thermo Fisher Scientific), which contains 295,988 markers [single-nucleotide polymorphisms (SNPs) and rare variants], and transferred to the GeneTitan Instrument (Affymetrix).

RESULTS

We found 15 SNPs (P < .001), 18 genes (P < .005), and 4 pathways (P < .05) related to cytokine-cytokine receptor interaction, natural killer cell-mediated cytotoxicity, regulation of autophagy, and renin-angiotensin system as the most strongly associated with frailty.

CONCLUSIONS/IMPLICATIONS

The specific genetic features related to energy metabolism, biological processes regulation, cognition, and inflammation highlighted by this preliminary analysis offer useful insights for finding biologically meaningful biomarkers of frailty that allow early diagnosis and treatment. Further research is needed to confirm our novel findings in a larger population. Indeed, the EU-funded FRAILOMICS research effort will address this question.

Centenarians Overexpress Pluripotency-Related Genes

Human mesenchymal cells can become pluripotent by the addition of Yamanaka factors OCT3/4, SOX2, c-MYC, KLF4. We have recently reported that centenarians overexpress BCL-xL, which has been shown to improve pluripotency; thus, we aimed to determine the expression of pluripotency-related genes in centenarians. We recruited 22 young, 32 octogenarian, and 47 centenarian individuals and determined the mRNA expression of Yamanaka factors and other stemness-related cell surface marker genes (VIM, BMP4, NCAM, BMPR2) in peripheral blood mononuclear cells by reverse transcription polymerase chain reaction. We found that centenarians overexpress OCT3/4, SOX2, c-MYC, VIM, BMP4, NCAM, and BMPR2, when compared with octogenarians (p < .05). We further tested the functional role of BCL-xL in centenarians’ ability to express pluripotency-related genes: lymphocytes from octogenarians transduced with BCL-xL overexpressed SOX2, c-MYC, and KLF4. We conclude that centenarians overexpress Yamanaka Factors and other stemness-related cell surface marker genes, which may contribute to their successful aging.

[Identification of single nucleotide polymorphisms related to frailty]

INTRODUCTION

The search for biomarkers that can lead to the early diagnosis and thus, early treatment of frailty, has become one of the main challenges facing the geriatric scientific community. The aim of the present study was to identify single nucleotide polymorphisms (SNPs) related to frailty.

MATERIAL AND METHODS

The study was conducted on 152 subjects from the Toledo Study for Healthy Aging (65 to 95 years of age), and classified as frail (n=78), and non-frail (n=74), according to Fried's criteria. After blood collection, DNA was isolated and amplified for the analysis of SNPs using Axiom^TM Genotyping technology (Affymetrix). Statistical analyses were performed using the Plink program and library SNPassoc.

RESULTS

The results of the study showed 15 SNPs with a P<.001. Those SNPs involved in processes related to frailty, such as energy metabolism, regulation of biological processes, cell motility and integrity, and cognition are highlighted.

CONCLUSIONS

These results suggest that the genetic variations identified in frail individuals that are involved in biological processes related to frailty may be considered as biomarkers for the early detection of frailty.

Role of p16INK4a and BMI-1 in oxidative stress-induced premature senescence in human dental pulp stem cells

Human dental pulp stem cells (hDPSCs) are a source for cell therapy. Before implantation, an in vitro expansion step is necessary, with the inconvenience that hDPSCs undergo senescence following a certain number of passages, loosing their stemness properties. Long-term in vitro culture of hDPSCs at 21% (ambient oxygen tension) compared with 3-6% oxygen tension (physiological oxygen tension) caused an oxidative stress-related premature senescence, as evidenced by increased β-galactosidase activity and increased lysil oxidase expression, which is mediated by p16^INK4a pathway. Furthermore, hDPSCs cultured at 21% oxygen tension underwent a downregulation of OCT4, SOX2, KLF4 and c-MYC factors, which was recued by BMI-1 silencing. Thus, p16^INK4a and BMI-1 might play a role in the oxidative stress-associated premature senescence. We show that it is important for clinical applications to culture cells at physiological pO₂ to retain their stemness characteristics and to delay senescence.

Role of oestrogens on oxidative stress and inflammation in ageing

Abstract Females live longer than males. We have shown that this could be in part due to the higher levels of oestrogens in females, which protect them against ageing, by up-regulating the expression of antioxidant, longevity-related genes. However, the low concentration of oestrogens makes it unlikely that they exhibit significant antioxidant capacity in the organism. Our results show that physiological concentrations of oestrogens activate the expression of manganese superoxide dismutase and glutathione peroxidase by oestrogen receptors and the mitogen-activated protein kinase and nuclear factor kappa B pathway. Moreover, when considering oestrogen replacement therapy, it is of utmost importance to take into account when to start the therapy after menopause. We have shown that only early-onset administration of oestrogen replacement therapy is effective on oestrogen deprivation associated with oxidative and metabolic stress. This is due to a change in oestrogen receptor distribution after oestrogen deprivation. Oestrogens are also involved in inflammatory processes. Their role on inflammation is very complex, because their effects are different depending on the doses and also on the oestrogen receptor distribution.

Exome sequencing of three cases of familial exceptional longevity

Exceptional longevity (EL) is a rare phenotype that can cluster in families, and co-segregation of genetic variation in these families may point to candidate genes that could contribute to extended lifespan. In this study, for the first time, we have sequenced a total of seven exomes from exceptionally long-lived siblings (probands ≥ 103 years and at least one sibling ≥ 97 years) that come from three separate families. We have focused on rare functional variants (RFVs) which have ≤ 1% minor allele frequency according to databases and that are likely to alter gene product function. Based on this, we have identified one candidate longevity gene carrying RFVs in all three families, APOB. Interestingly, APOB is a component of lipoprotein particles together with APOE, and variants in the genes encoding these two proteins have been previously associated with human longevity. Analysis of nonfamilial EL cases showed a trend, without reaching statistical significance, toward enrichment of APOB RFVs. We have also identified candidate longevity genes shared between two families (5–13) or within individual families (66–156 genes). Some of these genes have been previously linked to longevity in model organisms, such as PPARGC1A,NRG1,RAD52, RAD51, NCOR1, and ADCY5 genes. This work provides an initial catalog of genes that could contribute to exceptional familial longevity.

Activation of p38, p21, and NRF-2 mediates decreased proliferation of human dental pulp stem cells cultured under 21% O2

High rates of stem cell proliferation are important in regenerative medicine and in stem cell banking for clinical use. Ambient oxygen tensions (21% O₂) are normally used for in vitro culture, but physiological levels in vivo range between 3% and 6% O₂. We compared proliferation of human dental pulp stem cells (hDPSCs) cultured under 21% versus 3% O₂. The rate of hDPSC proliferation is significantly lower at 21% O₂ compared to physiological oxygen levels due to enhanced oxidative stress. Under 21% O_2, increased p38 phosphorylation led to activation of p21. Increased generation of reactive oxygen species and p21 led to activation of the NRF-2 signaling pathway. The upregulation of NRF-2 antioxidant defense genes under 21% O₂ may interact with cell-cycle-related proteins involved in regulating cell proliferation. Activation of p38/p21/NRF-2 in hDPSCs cultured under ambient oxygen tension inhibits stem cell proliferation and upregulates NRF-2 antioxidant defenses.

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hDPSC proliferation rate is significantly lower at 21% O₂ than at 3% O₂

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This is due to increased levels oxidative stress at 21% O₂

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Oxidative stress activates the cell signaling pathway p38 →p21 → NRF-2

Early, but not late onset estrogen replacement therapy prevents oxidative stress and metabolic alterations caused by ovariectomy

AIMS

The usefulness of estrogen replacement therapy (ERT) in preventing oxidative stress associated with menopause is controversial. We aimed to study if there is a critical time window for effective treatment of the effects of ovariectomy with estrogens at the molecular, metabolic, and cellular level.

RESULTS

Our main finding is that early, but not late onset of ERT prevents an ovariectomy-associated increase in mitochondrial hydrogen peroxide levels, oxidative damage to lipids and proteins, and a decrease in glutathione peroxidase and catalase activity in rats. This may be due to a change in the estrogen receptor (ER) expression profile: ovariectomy increases the ER α/β ratio and immediate estrogen replacement prevents it. Positron emission tomography analysis shows that ovariectomy decreases the brain glucose uptake in vivo and that estrogen administration is beneficial, but only if administered immediately after deprivation. Ovariectomy decreases GLUT-1 and 3 glucose transporters in the brain, and only early onset estrogen administration prevents it. Plasma from rats treated with estrogens immediately after ovariectomy show similar metabolomics profiles as controls.

INNOVATION

We provide molecular basis for the recommendation of early onset ERT and explain its lack of effectiveness if a significant time period elapses after ovariectomy and probably after the onset of menopause.

CONCLUSION

Only early, but not late onset administration of estrogens after ovariectomy has beneficial effects at molecular levels on oxidative stress, brain glucose uptake, and metabolomic profiles.

Approaches to aspects of optimisation of protection in diagnostic radiology in six continents

There has been an expansion in the use of x-ray imaging during the last 20 years. Effective arrangements for justification of exposures as well as for optimisation of protection are crucial. The amount of effort put into the latter, the way in which it is organised and the groups carrying this out vary across the globe. A simple survey of organisational arrangements relating to performance testing of x-ray equipment, management of patient dose and other aspects of implementing optimisation has been undertaken. A total of 137 completed survey forms were received from medical physicists in 48 countries. Results for individual countries from which more responses were received, or for groups of neighbouring ones, are compared to portray variations. Some performance testing of x-ray equipment was mandated in most countries (more than 90%), with the tests being performed primarily by hospital or private medical physicists, although other groups are involved. Testing of equipment prior to clinical use was generally high for most regions, but the frequency was lower in Latin America. There was considerable variation in the frequency and regularity of subsequent testing. The prevalence of patient dose surveys was high in Europe, but lower in other continents. Organisational arrangements for testing performance of x-ray equipment, patient dose surveys and implementing optimisation of protection in medical exposures across the globe can be divided into five main groups. Hospital medical physicists take the lead in western Europe and Australia with the involvement of radiographers. Private medical physicists test equipment in Brazil, the USA and New Zealand, and have some responsibility for optimisation in Brazil. University personnel have significant involvement, together with medical physicists in eastern Europe, but the extent of the coverage is uncertain. Government personnel and service engineers carry out equipment testing in many countries of Africa and Asia, while radiographers have a significant role in Thailand and other countries where the number of medical physicists is limited. In order for dose surveys to have an impact, action must be taken upon the findings, but there must be an effective link between surveyors and radiology facility staff to ensure that this is done.

[Resveratrol: distribution, properties and perspectives]

Resveratrol is a natural polyphenol which can be found in many plants and fruits, such as peanuts, mulberries, blueberries and, above all, in grapes and red wine. Its synthesis is regulated by the presence of stressful factors, such as fungal contamination and ultra-violet radiation. In plants, it plays a role as a phytoalexin, showing a capacity to inhibit the development of certain infections. Plant extracts which contain resveratrol have been employed by traditional medicine for more than 2000 years. Resveratrol was first isolated, and its properties were initially studied with scientific methods, thirty years ago. Its in vitro properties have been extensively studied and demonstrated. It is worth highlighting its activity as an anti-cancer agent, platelet anti-aggregation agent, anti-inflammatory, antiallergenic, etc. The activity of its in vivo properties are not so clear. There are many studies that report benefits on the cardiovascular system, illnesses such as diabetes, and in longevity. However, other authors did not find any agreement between in vitro and in vivo studies. This discrepancy is due to the bioavailability of resveratrol. After an oral dose, it has been demonstrated that the absorption is very high, but the metabolic pathways leave just a little free resveratrol in blood, therefore the bioavailability in the target tissues is very low and the concentrations used in in vitro studies are not found in these tissues. Thus, resveratrol is a very active molecule for maintaining health, but due to the low bioavailability not all the in vitro effects can be translated to in vivo. This opens a new potential approach, seeking derivatives of resveratrol that can be measured in the desired tissues.

Organ doses and risks of computed tomography examinations in Recife, Brazil

Computed tomography (CT) examinations have increased significantly in recent years due to technological innovations. In some industrialised countries, CT contributes to the population dose as much as background radiation. In developing countries, the uses and risks of CT have not been well characterised. The purpose of this investigation was to assess potential stochastic and deterministic radiation effects from common CT exams performed in six hospitals of Recife, Pernambuco. Scanning parameters and patient gender and age were collected for a total of 285 patients undergoing CT examinations of the head (90), chest (75), abdomen (60) and abdomen-pelvis (60). The organ doses, which were calculated using the ImPACT dosimetry calculator, varied significantly among institutions. Organs such as the brain, the heart and the eye lenses, which exhibited doses as high as 85, 42 and 100 mGy, respectively, are of concern for the production of cerebrovascular and cardiovascular diseases and cataracts. Effective cancer risks were calculated using Brenner methodology and BEIR-VII risk factors. They range from 1.8 to 110.2 cases per 100000 persons for cancer induction and from 1.5 to 63.0 cases per 100000 for cancer mortality. To reduce doses, a quality assurance programme that includes procedural justification and radiation protection optimisation should be implemented.

The dual role of p53: DNA protection and antioxidant

The classical functions of p53 protein are those related to its role on DNA damage, cell growth arrest, senescence and apoptosis. For this reason it is called 'the guardian of the genome' and is considered one of the most important players in the development of cancer. However, more recently it has been show that p53 is not only involved in cancer, but also in ageing. p53 is stimulated by stress, which in turn results in the activation of a wide range of transcriptional targets. Low-intensity stress will activate p53 in a manner which results in antioxidant response, thus protecting against ageing because of its antioxidant function. On the contrary, high-intensity activation of p53 will result in an increase of oxidative stress by activation of p53-mediated pro-oxidant targets, thus increasing the rate of ageing, but protecting against cancer.