Francesco De Rango

Exploring the Role of Genetic Variability and Lifestyle in Oxidative Stress Response for Healthy Aging and Longevity

Oxidative stress is both the cause and consequence of impaired functional homeostasis characterizing human aging. The worsening efficiency of stress response with age represents a health risk and leads to the onset and accrual of major age-related diseases. In contrast, centenarians seem to have evolved conservative stress response mechanisms, probably derived from a combination of a diet rich in natural antioxidants, an active lifestyle and a favorable genetic background, particularly rich in genetic variants able to counteract the stress overload at the level of both nuclear and mitochondrial DNA. The integration of these factors could allow centenarians to maintain moderate levels of free radicals that exert beneficial signaling and modulator effects on cellular metabolism. Considering the hot debate on the efficacy of antioxidant supplementation in promoting healthy aging, in this review we gathered the existing information regarding genetic variability and lifestyle factors which potentially modulate the stress response at old age. Evidence reported here suggests that the integration of lifestyle factors (moderate physical activity and healthy nutrition) and genetic background could shift the balance in favor of the antioxidant cellular machinery by activating appropriate defense mechanisms in response to exceeding external and internal stress levels, and thus possibly achieving the prospect of living a longer life.

Further Support to the Uncoupling-to-Survive Theory: The Genetic Variation of Human UCP Genes Is Associated with Longevity

In humans Uncoupling Proteins (UCPs) are a group of five mitochondrial inner membrane transporters with variable tissue expression, which seem to function as regulators of energy homeostasis and antioxidants. In particular, these proteins uncouple respiration from ATP production, allowing stored energy to be released as heat. Data from experimental models have previously suggested that UCPs may play an important role on aging rate and lifespan. We analyzed the genetic variability of human UCPs in cohorts of subjects ranging between 64 and 105 years of age (for a total of 598 subjects), to determine whether specific UCP variability affects human longevity. Indeed, we found that the genetic variability of UCP2, UCP3 and UCP4 do affect the individuals chances of surviving up to a very old age. This confirms the importance of energy storage, energy use and modulation of ROS production in the aging process. In addition, given the different localization of these UCPs (UCP2 is expressed in various tissues including brain, hearth and adipose tissue, while UCP3 is expressed in muscles and Brown Adipose Tissue and UCP4 is expressed in neuronal cells), our results may suggest that the uncoupling process plays an important role in modulating aging especially in muscular and nervous tissues, which are indeed very responsive to metabolic alterations and are very important in estimating health status and survival in the elderly.

Bitter Taste Receptor Polymorphisms and Human Aging

Several studies have shown that genetic factors account for 25% of the variation in human life span. On the basis of published molecular, genetic and epidemiological data, we hypothesized that genetic polymorphisms of taste receptors, which modulate food preferences but are also expressed in a number of organs and regulate food absorption processing and metabolism, could modulate the aging process. Using a tagging approach, we investigated the possible associations between longevity and the common genetic variation at the three bitter taste receptor gene clusters on chromosomes 5, 7 and 12 in a population of 941 individuals ranging in age from 20 to 106 years from the South of Italy. We found that one polymorphism, rs978739, situated 212 bp upstream of the TAS2R16 gene, shows a statistically significant association (p = 0.001) with longevity. In particular, the frequency of A/A homozygotes increases gradually from 35% in subjects aged 20 to 70 up to 55% in centenarians. These data provide suggestive evidence on the possible correlation between human longevity and taste genetics.

A cross-section analysis of FT3 age-related changes in a group of old and oldest-old subjects, including centenarians' relatives, shows that a down-regulated thyroid function has a familial component and is related to longevity.

Background: several studies suggest that a decreased thyroid activity might be favourable in oldest-old subjects and that subclinical thyroid hyperfunction may be detrimental. Objectives: to verify whether declining levels of circulating thyroid hormones may contribute to longevity. Design: cross-sectional observational study. Setting: all subjects were born in Calabria (southern Italy) and their ancestry in the region was ascertained up to the grandparents. Subjects: six hundred and four home-dwelling subjects (301 females, 303 males), divided into three groups: 278 individuals 60–85 years old; 179 children or nieces/nephews of centenarians who are 60–85 years old; 147 individuals older than 85 years. Methods: thyroid function parameters were measured in the frame of a comprehensive geriatric assessment. Results: FT3 and FT4 levels were negatively associated with age. Lower levels of FT3, FT4 and TSH were found in centenarians’ children and nieces/nephews with respect to age-matched controls. Indeed, being a relative of centenarians qualified as an independent correlate of thyroid parameters. Conclusions: age-related subtle thyroid hypofunction (either due to a familial component or due to a reset of the thyroid function occurring between the sixth and the eighth decade of life) appears to be related to longevity.

A novel sampling design to explore gene-longevity associations: the ECHA study

To investigate the genetic contribution to familial similarity in longevity, we set up a novel experimental design where cousin-pairs born from siblings who were concordant or discordant for the longevity trait were analyzed. To check this design, two chromosomal regions already known to encompass longevity-related genes were examined: 6p21.3 (genes TNFα, TNFβ, HSP70.1) and 11p15.5 (genes SIRT3, HRAS1, IGF2, INS, TH). Population pools of 1.6, 2.3 and 2.0 million inhabitants were screened, respectively, in Denmark, France and Italy to identify families matching the design requirements. A total of 234 trios composed by one centenarian, his/her child and a child of his/her concordant or discordant sib were collected. By using population-specific allele frequencies, we reconstructed haplotype phase and estimated the likelihood of Identical By Descent (IBD) haplotype sharing in cousin-pairs born from concordant and discordant siblings. In addition, we analyzed haplotype transmission from centenarians to offspring, and a statistically significant Transmission Ratio Distortion (TRD) was observed for both chromosomal regions in the discordant families (P=0.007 for 6p21.3 and P=0.015 for 11p15.5). In concordant families, a marginally significant TRD was observed at 6p21.3 only (P=0.06). Although no significant difference emerged between the two groups of cousin-pairs, our study gave new insights on the hindrances to recruiting a suitable sample to obtain significant IBD data on longevity-related chromosomal regions. This will allow to dimension future sampling campaigns to study-genetic basis of human longevity.

Urinary Incontinence in the Elderly and in the Oldest Old: Correlation with Frailty and Mortality

Urinary incontinence (UI) is very common in the elderly and has personal and social implications. Many authors have pointed out the necessity to analyze UI in correlation with the overall quality of aging, to better understand this syndrome and define measures for its prevention and treatment. In the present study, we addressed this problem by analyzing the UI correlation with frailty, which has emerged in the last decade as the geriatric syndrome correlated with individual homeostatic capacity and then as the basis of the age-related physical decline. In addition, the monitoring of our sample for a long period allowed us to estimate the prognostic significance of UI by analyzing the correlation between UI and mortality. The analysis was performed in a large sample that included numerous ultra-nonagenarians, a population segment that is still poorly known for UI and other geriatric parameters. We found a strict correlation between UI and frailty, suggesting that UI is correlated to the homeostatic and physiological decline leading to frailty. In addition, we found that UI is an independent mortality risk factor in ultra-nonagenarians, suggesting that the neurological sensitivity needed to be continent is lost very soon when the frailty associated physiological decline begins. On the whole, our study suggests that UI is a marker of frailty and that UI patients should be monitored and, in case, treated in a timely manner to avoid, or to limit, the effects of frailty such as malnutrition, falls, and the consequent accumulation of disabilities.

To grow old in southern Italy: A comprehensive description of the old and oldest old in Calabria

Background: The unprecedented growth of the elderly population is posing important social and medical problems as management of this population is highly demanding in terms of assistance and care. Consequently, many studies are focusing on the elderly subjects in order to better understand their needs by identifying various environmental, social, psychological, and genetic factors determining the quality of ageing. Objectives: Our aim was to carry out a survey of the elderly Calabrian population in order to highlight the social and medical conditions of this continuously growing population group. Methods: We have been monitoring the elderly population of Calabria for more than 10 years. For the present study, we collected data regarding 853 subjects by using two specific questionnaires, one for the subjects older than 90 years (400 subjects) and one for the subjects aged between 65 and 85 years (453 subjects). Results: The survey allowed us to carry out an extensive description of the ageing Calabrian population regarding the sociodemographic characteristics, living conditions, cognitive functioning, level of independence in activities of daily living, former and current diseases and health disorders. We could notice that males were in a better condition than females. In fact, male subjects turned out to have better physical performance and lower comorbidity, although their life expectancy is lower. Ultranonagenarians had a lower incidence of serious diseases (such as diabetes, osteoporosis and gastric ulcer), but a higher incidence of non-fatal chronic, debilitating conditions (cataract and bronchitis among others). Conclusion: The data we collected and analyzed offer a portrait of elderly Calabrian subjects, on who they are, how they feel, which social and psychological resources they have, and what their health status is. Analysis of the data highlighted that they are characterized by a lower physical performance in comparison to other European populations. Finally, the data presented here may also serve as a valuable source of information to characterize the ageing Calabrian population and improve the care of these subjects.

Estimating Glomerular Filtration Rate in Older People

We aimed at reviewing age-related changes in kidney structure and function, methods for estimating kidney function, and impact of reduced kidney function on geriatric outcomes, as well as the reliability and applicability of equations for estimating glomerular filtration rate (eGFR) in older patients. CKD is associated with different comorbidities and adverse outcomes such as disability and premature death in older populations. Creatinine clearance and other methods for estimating kidney function are not easy to apply in older subjects. Thus, an accurate and reliable method for calculating eGFR would be highly desirable for early detection and management of CKD in this vulnerable population. Equations based on serum creatinine, age, race, and gender have been widely used. However, these equations have their own limitations, and no equation seems better than the other ones in older people. New equations specifically developed for use in older populations, especially those based on serum cystatin C, hold promises. However, further studies are needed to definitely accept them as the reference method to estimate kidney function in older patients in the clinical setting.

Statecharts-based JADE agents and tools for engineering multi-agent systems

In this paper we propose frameworks and tools supporting a Statecharts-based development of JADE-based multi-agent systems (MASs) with the purpose of providing an effective approach for engineering MASs and leveraging agent-oriented development methodologies and processes adopting JADE as target agent platform. In particular, a framework for programming JADE behaviors through a variant of the Statecharts, named Distilled StateCharts (DSCs), has been first developed by enhancing the JADE add-on HSMBehaviour. Then, to enable rapid prototyping of JADE agents, a visual tool for DSCs has been extended with translation rules based on the developed framework which allows to automatically translate DSC specifications into DSC-based JADE behaviors. The proposed approach is exemplified through a case study concerning an agent-based meeting organization system.

Translation of statechart agents into a BDI framework for MAS engineering

In the agent-oriented computing area, different programming paradigms have been to date proposed to design and implement multi-agent systems (MAS). Among them, the Belief-Desire-Intention (BDI) and Statecharts-based models have emerged as they effectively support the definition of rational and protocol-oriented agent behaviors, respectively. In this paper, we investigate the translation between such models by using two available agent modeling languages: PROFETA, which is based on the BDI agent model, and the agent-oriented Distilled StateCharts (DSC) formalism, which allows modeling agent behaviors based on Statecharts-like state machines. In particular, we propose a mapping from DSC to PROFETA that can enable visual programming of PROFETA programs to facilitate the development of PROFETA-based autonomous systems. A case-study is also developed to exemplify the proposed engineering approach.