A genetic-demographic approach reveals male-specific association between survival and tumor necrosis factor (A/G)-308 polymorphism

SARS CoV2 infection _The longevity study perspectives

Like other infectious diseases, COVID-19 shows a clinical outcome enormously variable, ranging from asymptomatic to lethal. In Italy, like in other countries, old male individuals, with one or more comorbidity, are the most susceptible group, and show, consequently, the highest mortality, and morbidity, including lethal respiratory distress syndrome, as the most common complication. In addition, another extraordinary peculiarity, that is a surprising resistance to COVID-19, characterizes some Italian nonagenarians/centenarians. Despite having the typical COVID-19 signs and/or symptoms, such exceptional individuals show a surprising tendency to recover from illness and complications. On the other hand, long-lived people have an optimal performance of immune system related to an overexpression of anti-inflammatory variants in immune/inflammatory genes, as demonstrated by our and other groups. Consequently, we suggest long-lived people as an optimal model for detecting genetic profiles associated with the susceptibility and/or protection to COVID-19, to utilize as potential pharmacological targets for preventing or reducing viral infection in more vulnerable individuals.

Association of Hypomorphic P2X7 Receptor Genotype With Age

One of the main risk factors for brain diseases is aging. Recent studies have shown that aging is a progressive degenerative process associated with chronic low-level inflammation. The ATP-gated P2X7 receptor (P2X7R) plays an important role in inflammation and has been associated with different brain (e.g., Alzheimer’s and Parkinson’s) or other age-related (osteoporosis, arthritis, cancer) diseases. Several single nucleotide polymorphisms (SNPs) in the P2RX7 gene have been identified, including the loss-of-function 1513A>C and 1405A>G SNPs, and the gain-of-function 489C>T and 1068G>A SNPs. We carried out a literature analysis to verify an association between P2RX7 SNPs’ frequency and age. In 34 worldwide eligible studies (11.858 subjects) no correlation between 1513CC genotype frequency and age emerged. On the contrary, analysis of European Caucasian cohorts (7.241 subjects) showed a significant increase in 1513CC frequency with age (P = 0.027). In agreement with these findings, analysis of two publicly available datasets, including USA Caucasian cohorts, unveiled an increased frequency of 1513CC and 489CC genotypes with age (P = 0.0055 and P = 0.0019, respectively). Thus, hypomorphic P2RX7 genotypes may be positively selected with age in European and North American Caucasian populations. We hypothesize that Caucasian individuals bearing an anti-inflammatory P2X7R phenotype and living in high-income countries may have a longer life expectancy.

Human longevity: Genetics or Lifestyle? It takes two to tango

Healthy aging and longevity in humans are modulated by a lucky combination of genetic and non-genetic factors. Family studies demonstrated that about 25 % of the variation in human longevity is due to genetic factors. The search for genetic and molecular basis of aging has led to the identification of genes correlated with the maintenance of the cell and of its basic metabolism as the main genetic factors affecting the individual variation of the aging phenotype. In addition, studies on calorie restriction and on the variability of genes associated with nutrient-sensing signaling, have shown that ipocaloric diet and/or a genetically efficient metabolism of nutrients, can modulate lifespan by promoting an efficient maintenance of the cell and of the organism. Recently, epigenetic studies have shown that epigenetic modifications, modulated by both genetic background and lifestyle, are very sensitive to the aging process and can either be a biomarker of the quality of aging or influence the rate and the quality of aging.

On the whole, current studies are showing that interventions modulating the interaction between genetic background and environment is essential to determine the individual chance to attain longevity.

A genetic-demographic approach reveals a gender-specific association of SLC6A3/DAT1 40 bp-VNTR with life-expectancy

Several recent lines of evidence are proving an important role for dopamine in the aging process and in the determination of life span. Components of the dopaminergic system may represent good candidates for longevity studies. Herein, we tested the possible association of the functional SLC6A3/DAT1 40-bp VNTR with life-expectancy in a healthy population of Central Italy (N = 993) by applying a genetic-demographic approach that takes into account the demographic information and different survival rates between sexes for modeling the survival of specific allele carriers in the population. Male carriers of S*/S* genotype showed a lower survival chance across most of the lifespan respect to the survival of DAT1*L-carriers (P = 0.021). The same analyses gave non-significant results in females. Several studies already reported significant sex differences in dopamine metabolism and its related biological pathways. Thus, we can hypothesize that the SLC6A3/DAT1 40 bp-VNTR may affect life expectancy in a sex-specific way. Moreover, it is conceivable that DAT1 S*/S* carriers, who are prone to assume "risk" type behaviors, may be dropped out of the "healthy" population by a sort of "demographic selection".

TNFα polymorphism as marker of immunosenescence for rheumatoid arthritis patients

BACKGROUND

Expansion of CD4(+)CD28(null), a common feature of immunosenescence, which has been reported in rheumatoid arthritis (RA) patients, may also be associated with a CD4(+) imbalance. Although the increase of CD4(+)CD28(null) cells has been related to TNFα exposure, nothing is known about the possible role of genetic variants of this cytokine.

METHODS

Participants were genotyped for TNFA rs1800629 (-308 G>A) and frequency of the CD4(+)CD28(null), regulatory T cells and Th1 cells subsets were quantified in peripheral blood samples by flow cytometry in 129 RA patients and 33 healthy controls.

RESULTS

The expansion of CD4(+)CD28(null) cells in RA patients was associated with TNFA genotype, even at diagnosis, and linked to markers of aggressive disease in patient carriers of the minor allele. Analysis of regulatory T cells and IFNγ-CD4(+) expression suggested that defective suppression and/or Th1-shift could underlie the expansion of this population in these patients. Finally, although treatment with TNFα-blockers reduced CD4(+)CD28(null) cells in most patients, only those carriers of the common GG genotype reached values within the range of HC and showed a disease activity improvement correlated to this decrease.

CONCLUSIONS

Our results provide evidence for a genetic basis of the premature immunosenescence of RA patients and highlight its potential role in clinical outcome after TNFα blockade.

The functional VNTR of IGH enhancer HS1.2 associates with human longevity and interacts with TNFA promoter diplotype in a population of Central Italy

The dysregulation of both immune and inflammatory responses occurring with aging is believed to substantially contribute to morbidity and mortality in humans. We have already reported the association of the functional Variable Number of Tandem Repeat (VNTR) at the Immunoglobulin heavy chain (IGH) enhancer HS1.2 with Immunoglobulin levels and with several autoimmune diseases. Herein we tested the association of the VNTR at the HS1.2 enhancer with human longevity, also evaluating the possible modulatory effect of TNFA promoter diplotype (rs361525/rs1800629). HS1.2 enhancer genotypes have been determined for 193 unrelated healthy individuals from Central Italy divided into two groups: Group 1 (18-84 yrs, mean age 56.8 ± 19.4) and Group 2 (85-100 yrs, mean age 93.0 ± 3.5). Homozygous subjects for 2 allele were significantly disadvantaged in reaching higher life-expectancy (OR=0.457, p=0.021). A significant interaction between TNFA promoter diplotype status, HS1.2 2/2 genotype and the two Groups was found (p=0.014). Of note, TNFA -308A allele seems to exert a protective effect in HS1.2 2/2 carriers. These results support the hypothesis of an important role of HS1.2 VNTR in the puzzle of the immune-system regulation, evidenced also by the potential interaction with TNFA. Moreover, the previous results showing the association of HS1.2 2 allele with inflammatory phenomena are consistent with the hypothesis that this allele is a detrimental factor in reaching advanced age.

Interleukin-10 promoter (-1082) polymorphism in association with repeated hospital-acquired infections in elderly patients

BACKGROUND

Infections are frequent complications of hospitalization, particularly in the elderly. Pro- and anti-inflammatory cytokines are essential components of the host response to pathogens and polymorphisms in their genes may contribute to inter-individual variations of the inflammatory response. The aim of this study was to investigate whether cytokine polymorphisms, separately or in combination, could be determining factors in the development of repeated nosocomial infections in elderly hospitalized patients.

METHODS

Tumor necrosis factor-α (-308) and (-238), interleukin-6 (-174) and (-6331), interleukin-10 (-1082) and (-592) polymorphisms were genotyped by PCR and hybridization with fluorescent-labeled probes in 245 hospitalized elderly patients (mean age 85.2 years; SD 6) and compared with those in 145 healthy adults.

RESULTS

The distribution of genotypes did not differ between elderly patients and control subjects. The presence of the interleukin-10 A(592) or A(1082) allele was more frequent individually and after adjustment for multiple comparisons in patients who suffered from several infections (p = 0.012, odds ratio = 5.3; 95 % confidence interval = 1.2-23.1).

CONCLUSION

Our data support a determinant role for interleukin-10 (-1082) polymorphism in the development of nosocomial infections.

Gender-specific association between FSHR and PPARG common variants and human longevity

Men and women have different life expectancies. Not unexpectedly, several genes involved in life span determination have been found to influence the probability of achieving longevity differently in men and women. This investigation examines the association between longevity and polymorphisms of follicle-stimulating hormone receptor (FSHR, Asn680Ser polymorphism) and peroxisome proliferator-activated receptor gamma (PPARG, Pro12Ala polymorphism), two genes that previous investigations suggested may exert a gender-specific influence on human longevity. A sample of 277 individuals (mean age, 82.9±5.7years) was recruited in 2000. On the basis of mortality data collected in 2009, the sample was divided into two groups of subjects surviving over 90 years (long-lived) or not (controls). The frequency of the FSHR 680 Ser/Ser genotype was significantly higher in the sample of long-lived women compared to controls, indicating that the FSHR 680 Ser/Ser genotype may favor survival to more than 90 years of age only in women (odds ratio [OR]=4.21; 95% confidence interval [CI], 1.10-16.10, p=0.036). In contrast, the frequency of the PPARG Pro/Ala genotype was significantly higher in the sample of male subjects who died before 90 years of age than in the long-lived, suggesting that carrying the PPARG Pro/Ala genotype may prevent the attainment of advanced age only in men (OR=0.13; 95% CI, 0.02-0.79; p=0.03). We then searched the literature for studies reporting a differential role for the genetic component in male and female longevity. To do this, we selected longevity genes with a gender-specific effect. A review of the studies showed that genetic factors tend to have a greater relevance in determining longevity in men than in women. The possible impact of this phenomenon is discussed.

Cytokine gene polymorphisms and Alzheimer's disease in Brazil

BACKGROUND

Single-nucleotide polymorphisms in genes encoding immunological mediators can affect the biological activity of these molecules by regulating transcription, translation, or secretion, modulating the genetic risk of inflammatory damage in Alzheimer's disease (AD). Nonetheless, the Brazilian contingent is highly admixed, and few association trials performed herein with AD patients have considered genetic ancestry estimates as co-variables when investigating markers for this complex trait.

METHODS

We analyzed polymorphisms in 10 inflammatory genes and compared the genotype distribution across outpatients with late-onset AD and noncognitively impaired subjects from Midwest Brazil under a strict criterion, and controlling for ancestry heritage and ApoE genotype.

RESULTS

Our findings show an almost 40% lower chance of AD (p = 0.004) among homozygotes of the IL10 -1082A allele (rs1800896). Dichotomization to ApoE and mean ancestry levels did not affect protection, except among those with greater European or minor African heritage.

CONCLUSION

The IL10 locus seems to affect the onset of AD in a context sensitive to the genetic ancestry of Brazilian older adults.

Epidemiological, genetic and epigenetic aspects of the research on healthy ageing and longevity

Healthy ageing and longevity in humans result from a number of factors, including genetic background, favorable environmental and social factors and chance.

In this article we aimed to overview the research on the biological basis of human healthy ageing and longevity, discussing the role of epidemiological, genetic and epigenetic factors in the variation of quality of ageing and lifespan, including the most promising candidate genes investigated so far. Moreover, we reported the methodologies applied for their identification, discussing advantages and disadvantages of the different approaches and possible solutions that can be taken to overcome them. Finally, we illustrated the recent approaches to define healthy ageing and underlined the role that the emerging field of epigenetics is gaining in the search for the determinants of healthy ageing and longevity.

Inflammation, chronic obstructive pulmonary disease and aging

PURPOSE OF REVIEW

Chronic obstructive pulmonary disease (COPD) is characterized by an abnormal persistent inflammatory response to noxious environmental stimuli, particularly cigarette smoke. The determinants of the dysregulated immune responses, which play a role both in the onset and continuation of COPD, are largely unknown. We examined several molecular mechanisms regulating the inflammatory pathway, such as cytokine polymorphisms, miRNA expression, and DNA methylation in COPD and aging, with the aim to provide evidence supporting the view that aging of the immune system may predispose to COPD.

RECENT FINDINGS

The incidence of COPD increases with age. The pathogenesis of the disease is linked to a chronic inflammation and involves the recruitment and regulation of innate and adaptive immune cells. A chronic systemic inflammation characterizes aging and has been correlated with many diseases, most of them age-related.

SUMMARY

COPD and aging are associated with significant dysregulation of the immune system that leads to a chronic inflammatory response. The similar molecular mechanisms and the common genetic signature shared by COPD and aging suggest that immunosenescence may contribute to the development of COPD.

Age- and gender-specific epistasis between ADA and TNF-α influences human life-expectancy

Aging is a complex phenotype with multiple determinants but a strong genetic component significantly impacts on survival to extreme ages. The dysregulation of immune responses occurring with increasing age is believed to contribute to human morbidity and mortality. Conversely, some genetic determinants of successful aging might reside in those polymorphisms for the immune system genes regulating immune responses. Here we examined the main effects of single loci and multi-locus interactions to test the hypothesis that the adenosine deaminase (ADA) and tumor necrosis factor alpha (TNF-α) genes may influence human life-expectancy. ADA (22G>A, rs73598374) and TNF-α (-308G>A, rs1800629; -238G>A, rs361525) functional SNPs have been determined for 1071 unrelated healthy individuals from Central Italy (18-106 years old) divided into three gender-specific age classes defined according to demographic information and accounting for the different survivals between sexes: for men (women), the first class consists of individuals<66 years old (<73 years old), the second class of individuals 66-88 years old (73-91 years old), and the third class of individuals>88 years old (>91 years old). Single-locus analysis showed that only ADA 22G>A is significantly associated with human life-expectancy in males (comparison 1 (age class 2 vs. age class 1), O.R. 1.943, P=0.036; comparison 2 (age class 3 vs. age class 2), O.R. 0.320, P=0.0056). Age- and gender-specific patterns of epistasis between ADA and TNF-α were found using Generalized Multifactor Dimensionality Reduction (GMDR). In comparison 1, a significant two-loci interaction occurs in females between ADA 22G>A and TNF-α -238G>A (Sign Test P=0.011). In comparison 2, both two-loci and three-loci interaction are significant associated with increased life-expectancy over 88 years in males. In conclusion, we report that a combination of functional SNPs within ADA and TNF-α genes can influence life-expectancy in a gender-specific manner and that males and females follow different pathways to attain longevity.

Biogerontology in Italy

In this paper experimental gerontology in Italy is reviewed on the basis of research developed in Academic and non Academic Centres. There are several groups across Italy working actively on basic science of aging producing high impact papers with a significant contribution to biogerontology. Some distinguished Italian scientist working abroad is also mentioned. Interesting issues on longevity and interventions on aging (including caloric restriction) and on aging brain are quoted. Relevant studies encompass the (glyco-)oxidative stress as direct damage mechanism and main process of theory of aging, other research lines include IGF-1, mitochondria DNA, obesity/sarcopenia and exercise and also an animal model for aging studies is reported. Notwithstanding financial restrictions and structure deficit the biogerontology research in Italy could be judged as good, but additional resources are necessary to keep this good rank.

Complex patterns of gene expression in human T cells during in vivo aging

Human aging is associated with complex alterations that contribute to remodelling of physiological processes and ultimately manifests in loss of tissue/organ function. Peripheral blood T cells do not escape this phenomenon and undergo profound remodelling with aging. Thus, investigating the effects of aging on T cells transcriptomics and identifying the underlying regulatory mechanisms can be of extreme importance to understand the aging process in the Immune System (IS). To this aim, we performed an analysis of gene expression data of T cells collected from peripheral blood of 25 healthy human donors of different age from 25 to more than 95 years, in order to characterize changes that occur throughout the entire adult lifespan. By means of microarray analysis, we observed large groups of genes exhibiting non-monotonic expression patterns over time: such behaviour, that could not be observed in typical "two-group" experiments (e.g. young vs. old people) highlights similarities in gene expression profiles of young and "successfully aged" individuals. Genes whose expression profiles change during lifespan were grouped into three main patterns (eigenmodes) to which different biological functions were significantly associated. The analysis of KEGG pathways to which these genes belong indicated that the biological processes altered in T cell aging are not only those typically associated with immune cells (Jak-STAT signalling, T cell receptor signalling, cytokine-cytokine receptor interactions, etc.) but also some not specific of immune cells, such as long-term depression, PPAR and mTOR signalling, glucose and glutathione metabolism, suggesting that T cell aging may be representative of a more generalised aging phenomenon. Thus, the T cell may represent a useful cellular model to study organismal aging. We further searched for over-represented transcription factor binding sites (TFBSs) in the promoter regions of genes clustered by similarity of their age-related patterns to evidence possible co-regulation. A comparison between over-representation of TFBSs and the time course of the corresponding transcription factor (TF) expression levels revealed that a restricted group of TFs may play a central role in driving aging-specific changes in gene expression of T cells.

Association of longevity with IL-10 -1082 G/A and TNF-alpha-308 G/A polymorphisms

Cytokines are crucial for the regulation of inflammation development in humans. Many studies have shown that variations in cytokine genes might play a role in determining human longevity. This study examined the changes in the gene pool relevant to the -308 G/A polymorphism in the promoter region of the proinflammatory cytokine tumour necrosis factor (TNF)-alpha gene and the -1082 G/A polymorphism in the promoter region of anti-inflammatory cytokine interleukin (IL)-10 gene with aging and survival selection occurs in the Jordanian population. IL-10 -1028 G/A and TNF-alpha-308 G/A were genotyped in 119 randomly selected elderly subjects (41 women and 78 men) with a mean age of 90.2 years and young control subjects of 118 (46 women and 72 men) with a mean age of 31.9 years. No significant differences were found in the genotype and allele frequencies of TNF-alpha gene variants between the two groups (P > 0.05) while the IL-10 genotype and allele frequencies were significantly associated with longevity in men (P < 0.05) but not in women (P < 0.05). Thus, IL-10 -1028 G/A polymorphism seems to play a role in the pathway to longevity in Jordanian men.

Commonly studied polymorphisms in inflammatory cytokine genes show only minor effects on mortality and related risk factors in nonagenarians

Systemic low-grade inflammation is consistently associated with functional status, cognitive functioning, multimorbidity, and survival in oldest olds. If inflammation is either a cause or a consequence of age-related pathology, genetic determinants of late-life survival can reside in cytokine genes polymorphisms, regulating inflammatory responses. The aim of this study was to test associations between commonly studied polymorphisms in interleukin (IL)6, IL10, IL15, and IL18, and tumor necrosis factor-alpha genes and late-life survival in a longitudinal cohort of nonagenarians: the Danish 1905 cohort. Additionally, associations were investigated between inflammatory markers and major predictors of mortality as cognitive and functional status. Modest sex-specific associations were found with survival, cognitive functioning, and handgrip strength. Evaluation of combined genotypes indicated that, in nonagenarian men, the balance of pro- and anti-inflammatory activity at IL18 and IL10 loci is protective against cognitive decline. In conclusion, in this large study with virtually complete follow-up, commonly studied polymorphisms in cytokine genes do not have a major impact on late-life survival or associated risk phenotypes.

Why do centenarians escape or postpone cancer? The role of IGF-1, inflammation and p53

BACKGROUND

Centenarians are exceptionally long living individuals who escaped the most common age-related diseases. In particular they appear to be effectively protected from cancers. The mechanisms that underlie this protection are quite complex and still largely unclear.

AIM

To critically analyse the literature in order to propose a unifying hypothesis that can account for this cancer protection in centenarians.

METHODS

Review of the scientific literature regarding three main players in tumourigenesis such as IGF-1, inflammation and p53, and centenarians.

RESULTS

Centenarians appear to be characterised by low IGF-1-mediated responses and high levels of anti-inflammatory cytokines such as IL-10 and TGF-beta, a condition that results in protection from cancer. Both inflammation and IGF-1 pathway converge on the tumour suppressor p53. Accordingly, some studies indicate that genetic variants of p53 are associated with human longevity by providing protection from cancer mortality.

CONCLUSIONS

The available data let us to hypothesise that among other possible mechanisms, well-preserved p53-mediated responses are likely a key factor contributing to protection from cancer in centenarians.

Genetic association of FOXO1A and FOXO3A with longevity trait in Han Chinese populations

FOXO1A and FOXO3A are two members of the FoxO family. FOXO3A has recently been linked to human longevity in Japanese, German and Italian populations. Here we tested the genetic contribution of FOXO1A and FOXO3A to the longevity phenotype in Han Chinese population. Six tagging SNPs from FOXO1A and FOXO3A were selected and genotyped in 1817 centenarians and younger individuals. Two SNPs of FOXO1A were found to be associated with longevity in women (P = 0.01-0.005), whereas all three SNPs of FOXO3A were associated with longevity in both genders (P = 0.005-0.001). One SNP from FOXO1A was found not to be associated with longevity. In haplotype association tests, the OR (95% CI) for haplotypes TTG and CCG of FOXO1A in association with female longevity were 0.72 (0.58-0.90) and 1.38 (1.08-1.76), P = 0.0033 and 0.0063, respectively. The haplotypes of FOXO3A were associated with longevity in men [GTC: OR (95% CI) = 0.67 (0.51-0.86), P = 0.0014; CGT: OR (95% CI) = 1.48 (1.12-1.94), P = 0.0035] and in women [GTC: OR (95% CI) = 0.75 (0.60-0.94), P = 0.0094; CGT: OR (95% CI) = 1.47 (1.16-1.86), P = 0.0009]. The haplotype association tests were validated by permutation analysis. The association of FOXO1A with female longevity was replicated in 700 centenarians and younger individuals that were sampled geographically different from the original population. Thus, we demonstrate that, unlike FOXO3A, FOXO1A is more closely associated with human female longevity, suggesting that the genetic contribution to longevity trait may be affected by genders.

Human longevity and 11p15.5: a study in 1321 centenarians

The 11p15.5 chromosomal region (2.8 Mb) is of particular interest as it encloses five genes (HRAS1, SIRT3, TH, INS and IGF2), the variability of which was found to be associated with life extension by association studies. Mostly important, the above genes are homologous of genes that modulate lifespan in model organisms. We scanned the area in four European sample groups for a total of 1321 centenarians and 1140 younger subjects, who shared with centenarians ethnicity and geographical origin, with a set of 239 SNPs. No significant results (P<0.05) have been found on the earlier associated loci (ie, TH, IGF2, INS and HRAS1), and this study could not confirm the earlier findings on each of those genes. A meta-analysis was carried out on the SIRT3 SNP data; a total number of 2461 samples were included, but no positive association was found except for one SNP having a significant effect (rs939915). The same meta-analysis approach has been applied to the other 229 markers, and six SNPs have been found significant for the frequent genotype (rs4073591, DEAF1-rs4073590, KRTAP5-6-rs11040489, rs4930001, TSPAN32-rs800140 and rs16928120). This experience, although unable to confirm the earlier findings of the literature, highlights all the common difficulties of such studies in human longevity. Despite the rather negative findings presented here, the results derived from unprecedented studies involving such a large number of centenarians should be disseminated, thus contributing to set up adequate strategies to disentangle complex and likely heterogeneous phenotypes.

Genetic polymorphisms of RANTES, IL1-A, MCP-1 and TNF-A genes in patients with prostate cancer

BACKGROUND

Inflammation has been implicated as an etiological factor in several human cancers, including prostate cancer. Allelic variants of the genes involved in inflammatory pathways are logical candidates as genetic determinants of prostate cancer risk. The purpose of this study was to investigate whether single nucleotide polymorphisms of genes that lead to increased levels of pro-inflammatory cytokines and chemokines are associated with an increased prostate cancer risk.

METHODS

A case-control study design was used to test the association between prostate cancer risk and the polymorphisms TNF-A-308 A/G (rs 1800629), RANTES-403 G/A (rs 2107538), IL1-A-889 C/T (rs 1800587) and MCP-1 2518 G/A (rs 1024611) in 296 patients diagnosed with prostate cancer and in 311 healthy controls from the same area.

RESULTS

Diagnosis of prostate cancer was significantly associated with TNF-A GA + AA genotype (OR, 1.61; 95% CI, 1.09-2.64) and RANTES GA + AA genotype (OR, 1.44; 95% CI, 1.09-2.38). A alleles in TNF-A and RANTES influenced prostate cancer susceptibility and acted independently of each other in these subjects. No epistatic effect was found for the combination of different polymorphisms studied. Finally, no overall association was found between prostate cancer risk and IL1-A or MCP-1 polymorphisms.

CONCLUSION

Our results and previously published findings on genes associated with innate immunity support the hypothesis that polymorphisms in proinflammatory genes may be important in prostate cancer development.

Human models of aging and longevity

BACKGROUND

The aging phenotype in humans is very heterogeneous and can be described as a complex mosaic resulting from the interaction of a variety of environmental, stochastic and genetic-epigenetic variables. Therefore, each old person must be considered as a singleton, and consequently the definition of 'aging phenotype' is very difficult.

OBJECTIVE

We discuss the phenotype of centenarians, the best example of successful aging, as well as other models exploited to study human aging and longevity, such as families enriched in long-living subjects, twins and cohorts of unrelated subjects.

METHODS

A critical review of literature available until March 2008.

CONCLUSIONS

No single model can be considered the gold standard for the study of aging and longevity, instead the combination of results obtained from different models must be considered in order to better understand these complex phenomena. We propose that a systems biology concept such as that of 'bow-tie' architecture, useful for managing information flow, could help in this demanding task.

Inflammation, ageing and cancer

Cancer is generally recognized as an age-related disease. In fact, incidence and mortality rates of most human cancers increase consistently with age up to 90 years, but they plateau and decline thereafter. A low-grade systemic inflammation characterizes ageing and this pro-inflammatory status underlies biological mechanisms responsible for age-related inflammatory diseases. On the other hand, clinical and epidemiological studies show a strong association between chronic infection, inflammation and cancer and indicate that even in tumours not directly linked to pathogens, the microenvironment is characterized by the presence of a smouldering inflammation, fuelled primarily by stromal leukocytes. In this review, we have briefly mentioned inflammatory mediators involved in cancer although we decided to choose the ones which show a strict association with ageing and longevity. Inflammation is necessary to manage with damaging agents and is crucial for survival. But, in our opinion, the pro-inflammatory status of ageing might be one of the mechanisms which relate cancer to ageing. The most appropriate inflammatory genes have been selected to survive and to reproduce. Paradoxically, inflammatory age-related diseases (including cancer) are the marks of the same evolutionistic trait. Centenarians are characterized by a higher frequency of genetic markers associated with better control of inflammation. The reduced capacity of centenarians to mount inflammatory responses appears to exert a protective effect towards the development of those age-related pathologies having a strong inflammatory pathogenetic component, including cancer. All in all, centenarians seem to carry a genetic background with a peculiar resistance to cancer which is also an anti-inflammatory profile.