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Biomedical subjects

Claudio Franceschi

Publications and source records attributed to Claudio Franceschi.

At least 91 records · Page 5Linked to original sources
PubMed2003

Molecular variation of human HSP90alpha and HSP90beta genes in Caucasians.

Understanding DNA variation within the human genome is fundamental to the identification and interpretation of genetic components underlying complex traits and diseases. Despite their role in many crucial cellular pathways and their reported involvement in many complex diseases no data are available on the molecular variability of the genes coding for Heat Shock Proteins 90Kda (HSP90). Towards this purpose we have used DHPLC methodology to survey, a sample of Caucasians for genetic polymorphisms in the exons and exon-flanking regions of the expressed genes of human HSP90 gene families, HSP90alpha (HSPCAL4, 14q31.3) and HSP90beta (HSPCB, 6p12). A total of 18 and 11 variants were found in the HSP90-alpha and -beta genes respectively, providing an initial view of human genetic variation in these important genes. Only three of the observed mutations altered the genic product. Interestingly, one of the variations observed was a missense mutation leading to the impairment of the hsp90alpha protein.

DNA↗
PubMed2003

Allele frequencies of +874T --> A single nucleotide polymorphism at the first intron of IFN-gamma gene in Alzheimer's disease patients.

BACKGROUND AND AIMS: Inflammation seems to play a role in progressive neurological degenerative diseases such as Alzheimer's disease (AD). Local inflammatory processes can in fact give rise to direct neurotoxicity, interfere with beta-amyloid expression and metabolism, and maintain chronic, intracerebral, acute-phase protein secretion, in turn favoring the formation of beta-amyloid fibrils. Accordingly, recent studies show an increased risk for AD associated with certain polymorphisms in the genes encoding some proinflammatory cytokines and acute-phase proteins. To our knowledge, no data have yet been presented on the association between AD and polymorphisms of the interferon(IFN)-gamma gene, despite the pivotal role that IFN-gamma plays in immune-mediated inflammatory responses. METHODS: Using the amplification refractory mutation system method, we evaluated the role of IFN-gamma in AD by analyzing, in 111 AD patients and 213 healthy controls, the prevalence of +874T --> A single nucleotide polymorphism (SNP), associated with different IFN-gamma production. Allele ApoE polymorphisms were assessed by the PCR-based method. RESULTS: No statistically significant differences were observed between AD patients and controls in the frequency of +874T --> A SNP, either on analyzing data as a whole or according to gender. As expected, the frequency of the well-known genetic risk factor APOE-epsilon4 allele was significantly increased in AD patients. However, analyzing the results according to the presence or absence of the APOE-epsilon4 allele, no interactions among ApoE, IFN-gamma alleles, gender or age at onset were observed. CONCLUSIONS: Our study does not support the hypothesis that IFN-gamma SNP may be a genetic risk factor for AD. Further analysis of recently described IFN-gamma polymorphisms may clarify the role, if any, of IFN-gamma alleles in AD.

Adenine↗
PubMed2003

The MALVA (MAntova LongeVA) study: an investigation on people 98 years of age and over in a province of Northern Italy.

The MALVA (MAntova LongeVA) study aims at investigating the socio-demographic, clinical and genetic characteristics of all subjects over 98 years of age residing in the province of Mantova (Northern Italy). In this paper we present the study protocol and the main demographic results. Absolute number, prevalence ratio and female/male ratio of the subjects aged 98+ and of the centenarians in the Mantova province (370,645 inhabitants at 31st December 1997) were checked at the baseline of the study (31st March 1998) as well as in the two years preceding and following the study. A total of 117 subjects aged 98+ (including 39 centenarians) were traced at 31st March 1998; the prevalence ratio was 31.6 per 100000 (12.1 for centenarians), and the female/male ratio was 6.3 (6.5 for centenarians). The distribution of the oldest old according to places of birth and residence was non-homogeneous across the provincial territory. Seventy-seven subjects (66% of the identified subjects) were enrolled in the study and administered a protocol including an interview about socio-economic conditions, lifetime habits and pathological and pharmacological case histories, as well as medical examination, performance-based tests and blood sample collection. Data on the socio-demographic characteristics and the health status of very old people in the province of Mantova are discussed and compared to findings from previous studies on Italian centenarians.

Age Distribution↗
PubMed2003

Age-dependent changes in the susceptibility to apoptosis of peripheral blood CD4+ and CD8+ T lymphocytes with virgin or memory phenotype.

Susceptibility to apoptosis changes with age and most of the available data on lymphocytes refer to mitogen stimulated cells. We studied this susceptibility in quiescent, purified CD4+ or CD8+ T cells from a group of Italian old people compared with a group of young people. We found that an apoptotic agent such as 2-deoxy-D-ribose (dRib), which acts via glutathione depletion and oxidative stress, was more effective in CD4+ T cells from young donors, while no difference was found in CD8+ T cells. On the contrary, another agent such as TNF-alpha, which acts via receptor engagement, was more effective in CD8+ T cells from old subjects, and no difference was found in CD4+ T cells. When marker of activation-memory were investigated, no difference between young and old subjects was found when dRib was used. Differently, when TNF-alpha was used, memory and activated CD4+ T cells from old donors were less sensitive than younger counterparts, while memory CD8+ T cells from old donors were more sensitive than younger counterparts. This suggests that age-related changes in susceptibility to apoptosis of resting T cells largely depend on the type of the apoptotic stimulus which is used as well as on the memory phenotype of the cells. These results may also account, at least in part, for the deep remodelling of T cell repertoire that occurs during ageing.

Adult↗
PubMed2003

Metallothioneins/PARP-1/IL-6 interplay on natural killer cell activity in elderly: parallelism with nonagenarians and old infected humans. Effect of zinc supply.

Metallothioneins (MTs) play pivotal role in zinc-related cell homeostasis because of their high affinity for this trace element which is in turn relevant against oxidative stress and for the efficiency of the entire immune system, including natural killer (NK) cell activity. In order to accomplish this role, MTs sequester and/or dispense zinc during stress and inflammation to protect cells against reactive oxygen species. MTs gene expression is affected by IL-6 for a prompt immune response. Concomitantly, MTs release zinc for the activity of antioxidant zinc-dependent enzymes, including poly(ADP-ribose)polymerase-1(PARP-1), which is involved in base excision DNA-repair. This role of MTs is peculiar in young adult-age during transient stress and inflammation, but not in ageing because stress-like condition and inflammation are persistent. This may lead MTs to turn-off from role of protection in young age to deleterious one in ageing with subsequent appearance of age-related diseases (severe infections). The aim is to study the role played by MTs/IL-6/PARP-1 interplay on NK cell activity in elderly, in old infected patients (acute and remission phases by bronchopneumonia infection) and in health nonagenarian/centenarian subjects. MTmRNA is high in lymphocytes from elderly people coupled with high IL-6, low zinc ion bioavailability, decreased NK cell activity and impaired capacity of PARP-1 in base excision DNA-repair. The same trend in this altered physiological cascade during ageing also occurs in old infected patients (both acute and remission phases) with more marked immune damage, inflammatory condition and very impaired PARP-1 in base excision DNA-repair. By contrast, centenarian subjects display low MTmRNA, good zinc ion bioavailability, satisfactory NK cell activity and higher capacity of PARP-1 in base excision DNA-repair. These findings clearly demonstrate that the sequester of zinc by MTs in ageing is deleterious because leading to low zinc ion bioavailability with subsequent impairment of PARP-1 and NK cell activity and appearance of severe infections. Physiological zinc supply (12 mg Zn(++)/day) for 1 month in elderly and in old infected patients (remission phase) restores NK cells activity with values observed in health centenarians. Therefore, the zinc ion bioavailability by zinc-bound MTs homeostasis is pivotal to reach health longevity and successful ageing.

Adult↗
PubMed2003

Association between the HFE mutations and unsuccessful ageing: a study in Alzheimer's disease patients from Northern Italy.

Mutations in the class I-like Major Histocompatibility Complex gene HFE are associated with hereditary hemochromatosis (HH), a disorder caused by excessive iron uptake. Three common mutations have been found: C282Y, H63D, and S65C. Moreover, several studies have suggested that HFE mutations may be involved in several age-related chronic diseases such as Alzheimer's disease (AD) and coronary heart disease, but apparently paradoxically also with longevity. In particular, in AD, patients carrying the H63D allele have been suggested to have a mean age at onset of 72 vs. 77 years for those who were homozygous for the wild-type allele. Thus, it seems that H63D mutations may anticipate sporadic AD clinical presentation in susceptible individuals. In the present study, we analysed the HFE genotype in 123 patients with sporadic AD and 152 age-matched controls from Northern Italy. Samples were typed for C282Y, H63D and S65C alleles using the polymerase chain reaction and sequence specific primers. No significant differences were observed in frequencies of the different alleles between controls and AD both for the whole group and when the data were analysed according to gender. In addition, we failed to observe any difference in the age at onset between patients carrying the mutant HFE-H63D allele and those homozygous for the wild-type allele, either in men or women. Also taking into account the presence or absence of the APOE-epsilon 4 allele, no significant differences were observed between carriers of the mutant HFE-H63D allele and those homozygous for the wild-type allele. Thus, our study does not support the suggestion that H63D mutations may anticipate sporadic AD clinical presentation in susceptible individuals.

Aged↗
PubMed2003

Association between the HFE mutations and longevity: a study in Sardinian population.

Hereditary hemochromatosis is an HLA-linked inherited disease characterised by inappropriately high absorption of iron by the gastrointestinal mucosa. The cysteine-to-tyrosine substitution at codon 282 of the HFE encoding gene sequence is responsible for the disease, although other variants, as H63D and S65C, may modify the affinity of the protein for transferrin receptors. We have recently reported that C282Y mutation is significantly increased in very old (>90 years) Sicilian women, suggesting a role in attainment of longevity. In addition, an increase of H63D polymorphism was also observed in these women but the difference was not significant. To validate and extend these results we investigated the distribution of these three common HFE gene mutations in Sardinian centenarians and controls. DNA samples, obtained from 61 controls and 57 Centenarians, were typed for HFE polymorphisms using sequence specific primers. Among the controls, none was heterozygous for the C282Y mutation, 15 were heterozygous for H63D mutation and one for S65C. Among the centenarians, none was heterozygous for the C282Y mutation whereas 25 were heterozygous for H63D mutation and four for the S65C mutation. No significant differences were observed in frequencies of the different alleles between young and centenarians both on the whole and when the data were analysed according to gender. However, there was a trend for an increased frequency of H63D allele in centenarian women (24 vs. 17%, i.e. 19/80 vs. 13/78). It is noteworthy that the cumulative frequency of H63D mutations in Centenarian and very old women from Sardinia and Sicily is 22 vs. 11%, i.e. 30/136 vs. 23/210, P=0.008. These findings are consistent with the hypothesis that there may be a survival difference for centenarian women, among carriers and non-carriers of alleles involved in iron sparing.

Aged↗
PubMed2003

The role of IL-1 gene cluster in longevity: a study in Italian population.

In this study, we analysed the polymorphic variants of IL-1alpha (C-T transition at position -889), IL-1beta (C-T transition at position -511) and IL-1 receptor antagonist (Ra) (86-bp repeated sequence in intron 2) in 1131 subjects (453 females and 678 males) from Northern and Central Italy, including 134 centenarians, to evaluate whether IL-1 cluster alleles might be differently represented in people selected for longevity. In addition, IL-1Ra and IL-1beta plasma levels were quantified by ELISA in 130 randomly selected subjects. No significant differences in the genotype and allele frequency distributions were observed between young, elderly and centenarian subjects. IL-1Ra plasma levels showed an age-related increase, whereas IL-1beta plasma levels did not show any detectable age-related trend. Neither IL-1Ra nor IL-1beta plasma levels showed any relationship with genotypes of the three IL-1 genes. These results suggest that no one particular polymorphism in the IL-1 gene cluster yields an advantage for survival in the last decades of life, and that the age-related increase in plasma levels of IL-1Ra seems not to be genetically regulated but a likely safeguard mechanism to buffer the age-associated increased inflammatory state.

Adult↗
PubMed2003

In vitro IL-6 production by EBV-immortalized B lymphocytes from young and elderly people genotyped for -174 C/G polymorphism in IL-6 gene: a model to study the genetic basis of inflamm-aging.

In the present investigation we analysed Interleukin 6 (IL-6) in vitro production by Epstein-Barr virus (EBV)-immortalized B lymphocytes established from 43 subjects, 15 young people and 28 elderly people, including 18 centenarians, after 3, 6, 9, 24, 48 and 72 h of culture. The subjects were genotypized for the C to G transition at nucleotide -174 of IL-6 gene promoter (-174 C/G) and were classified as C allele carriers (C+) and non-carriers (C-). We found that: (i) the interindividual difference in in vitro IL-6 production was wider in elderly individuals in respect to young individuals, leading to different coefficient of variation in the two groups; (ii) the -174 C/G polymorphism had an age-related effect on IL-6 in vitro production. Only among C- people, cells from elderly subjects produced significant higher level of IL-6 than cells from young subjects. These data are consistent with our previous results regarding the IL-6 serum levels in a large group of people of different age, including centenarians. Thus, the EBV-immortalized B lymphocytes can be considered a useful in vitro model for studying the genetic control of IL-6 production and its changes with age.

Adult↗
PubMed2003

Interleukin-6 gene alleles affect the risk of Alzheimer's disease and levels of the cytokine in blood and brain.

Two different polymorphic regions of the interleukin-6 (IL-6) gene were investigated in patients with Alzheimer's disease (AD) and non-demented controls. The -174 C allele in the promoter region of IL-6 gene was over-represented in AD patients compared to controls and significantly increased the risk of AD. Moreover, the -174 CC genotype was associated with a high risk of the disease in women. The D allele of a variable number of tandem repeat (VNTR) was in strong linkage disequilibrium with the -174 C allele and slightly increased AD risk. On the other hand, the frequency of the VNTR C allele was decreased in patients with AD and was negatively associated with the risk of developing AD. Both the -174 CC and VNTR DD genotypes were also associated with increased IL-6 levels in the blood and brain from AD. These findings suggest that IL-6 may play a multifaceted role in AD by affecting the turnover of the cytokine.

3' Flanking Region↗
PubMed2003

Association between the HLA-DR alleles and longevity: a study in Sardinian population.

Human longevity may be correlated with optimal functioning of the immune system, suggesting that genetic determinants of longevity also resides in those polymorphisms for the immune system genes that regulate immune responses as histocompatibility (HLA) antigens. However, conflicting results have been obtained. Some well planned and designed association studies performed in Caucasians suggest that longevity is associated with positive selection of alleles (i.e. HLA-DR11) or haplotypes (i.e. HLA-B8,DR3) that confer resistance to infectious diseases, respectively, via peptide presentation or via antigen non-specific control of immune response. Association studies are subjected to a number of possible confounding factors, the homogeneity of the population in term of geographical origin among others. Because of the lack of large-scale heterogeneity, the Sardinians represent a suitable population for association studies addressed to dissect the complex traits as longevity. Thus, we have evaluated, by the amplification refractory mutation system/polymerase chain reaction, HLA-DR frequencies in 120 centenarians (79 women and 41 men) and 86 controls (53 women and 33 men) from Sardinia, to validate, in this very homogeneous population, the associations between HLA alleles or haplotypes and longevity observed in other Caucasoid populations. No significant differences were obtained by analysing the differences between Centenarians and controls except for HLA-DRB1*15 that was increased in centenarians. However, the significance was not maintained by multiplying P values for the number of alleles under study. Thus, in Sardinian centenarians, we were not able to confirm the findings observed in the well planned and designed studies performed in other Caucasoid populations. Besides, HLA HFE gene polymorphisms have been recently demonstrated to be associated with longevity in the Sicilian population but not in Danish one. On the whole these findings clearly show that HLA/longevity associations are population-specific, being heavily affected by the population-specific genetic and environmental history. So, in our opinion, HLA genes might be considered survival genes not longevity genes.

Aged↗
PubMed2003

Evidence for reduction of pro-atherosclerotic properties in platelets from healthy centenarians.

The aim of the present study was to investigate if aging is associated with platelet membrane modifications possibly related with cellular activation and hyperaggregability and if platelets from centenarians show different properties which might play a role in successful aging and longevity. Platelet plasma membranes were obtained from 60 healthy subjects, divided into four groups according to the age range: (1) 21-39 years; (2) 40-59 years; (3) 60-79 years; (4) centenarians (>/=100 years). Both centenarians and control subjects were submitted to the following inclusion criteria: liver, kidney, and thyroid function tests within the normal range; absence of history of diabetes, hypertension or coronary heart disease; no signs of edema or dehydration; no drug or vitamin supplement in the 4 weeks before the study; absence of Alzheimer's disease or secondary dementia. The following determinations were performed: lipid peroxide levels (Lp) evaluated by the measurement of thiobarbituric acid (TBA) reactivity, fluidity studied by the fluorescence anisotropy of the probe 1-(4-trimethylaminophenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH), Na(+)/K(+)-ATPase activity measured by the method of Kitao and Hattori, and sialic acid (SA) content evaluated by the periodate-thiobarbituric acid method. Centenarians showed: (i) Lp concentrations lower than elderly subjects; (ii) increased Na(+)/K(+)-ATPase activity compared with adult and elderly subjects; (iii) higher TMA-DPH anisotropy than elderly subjects; (iv) SA content similar to the young and adult groups.The present work found deep platelet membrane modifications in centenarians compared with elderly subjects. These changes are likely associated with a decreased platelet activation and therefore might exert a protective role against cardiovascular accidents, as platelet activation is a key event in the initiation and progression of arteriosclerosis.

Adult↗
PubMed2003

Increased circulating Interleukin-18 levels in centenarians with no signs of vascular disease: another paradox of longevity?

Interleukin (IL)-18 is highly expressed in macrophages from human atherosclerotic plaques, suggesting its involvement in ischemic syndromes. We evaluated IL-18 and IL-18 binding protein (BP) in healthy centenarians, as longevity is characterized by a reduced incidence of ischemic events. For comparison, patients with chronic ischemic syndromes (CIS) were evaluated. Serum IL-18 and IL-18BP levels were measured by non-cross-reacting ELISA in 16 healthy centenarians and in two age-control populations, each of 18 healthy individuals aged 55.9+/-1.43 and 74.3+/-1.35, respectively, as well as in 23 CIS patients, and another cohort of 23 healthy subjects that were age- and sex-matched with CIS patients. Centenarians displayed significantly higher total IL-18 serum levels compared to each control group. Elevated IL-18 levels were also present in CIS patients. However, centenarians had a significant higher level of IL-18BP compared to the cohort of 23 controls (P=0.0014), and compared to CIS patients (P=0.043); as a result centenarians exhibited a lower level of free IL-18 than CIS patients. The present results indicate that quenching of IL-18 by IL-18BP may explain the apparent paradox of elevated serum IL-18 with no vascular signs in centenarians.

Aged↗
PubMed2003

Marked increase with age of type 1 cytokines within memory and effector/cytotoxic CD8+ T cells in humans: a contribution to understand the relationship between inflammation and immunosenescence.

The ageing process is characterized by a progressive exhaustion of the naïve T cell reservoir that is accompanied by a compensatory expansion of effector/cytotoxic CD8+CD28- T cells. However, the origin and function of this subpopulation is not completely clarified. In this study, we examined the intracellular cytokine profile in purified CD8+ T cells obtained from 29 healthy subjects of different ages. Type 1 (IFN-gamma IL-2 and TNF-alpha) and type 2 (IL-4, IL-6 and IL-10) cytokines were determined in three CD8+ T subsets, i.e. CD95-CD28+ (naïve), CD95+CD28- (effector/cytotoxic), and CD95+CD28+ (memory). As a general trend, we observed, in aged subjects, an increase of type 1 and type 2 intracellular cytokines within the three CD8+ subsets. In particular, we showed that type 1 cytokine-positive cells significantly increased, with age, among all the CD8+ subsets, while a marked increase of type 2 producing cells was observed only in memory CD8+ T cells. These profound changes are compatible with inflame-aging, an hypothesis which suggest that immunosenescence is mainly driven by a chronic antigenic load which not only induces an enormous expansion of CD28- T cells, but also increases their functional activity, exemplified by an high frequency of cells positive for pro-inflammatory cytokines.

Adult↗
PubMed2003

Is chronic inflammation a determinant of blood pressure in the elderly?

BACKGROUND: Previous studies have shown that a rise in blood pressure (BP) causes chronic inflammation of the endothelium which, in turn, may be responsible for further damage of endothelium and worsening of BP control. On the other hand, several metabolic abnormalities such as dyslipidemia, hyperinsulinemia/insulin-resistance, diabetes, and obesity causes inflammation followed by a later rise in arterial BP. We investigated the role of chronic inflammation in the modulation of BP independently of other traditional cardiovascular risk factors and atherosclerotic lesions. METHODS: A total of 537 aged subjects, selected from the whole population of the INCHIANTI cohort, were enrolled. All subjects underwent plasma insulin, glucose, interleukin-6 (IL-6), interleukin-10 (IL-10), interleukin-1 beta (IL-1 beta), interleukin-1 receptor antagonist (IL-1ra), C-reactive protein, and tumor necrosis factor-alpha (TNF-alpha) levels determination. The IL-6-174 C/G promoter polymorphism was also evaluated. RESULTS: After adjusting for age, sex, insulin resistance syndrome score, and severity of carotid atherosclerosis, serum IL-1 beta (P <.001), IL-1ra (P <.005) concentration and the insulin resistance syndrome score (P <.001) were the only predictors of diastolic BP. Indeed, age (P <.001), insulin resistance syndrome score (P =.05), IL-1 beta (P <.05), and severity of carotid atherosclerosis (P <.05) were the only significant predictor of systolic BP. CONCLUSION: These results suggest that chronic inflammation may play a role in the modulation of arterial BP.

Aged↗
PubMed2003

Immunoproteasomes and immunosenescence.

Aging is a complex process which is accompanied with the decline and the reshaping of different functions of the body. In particular the immune system is characterized, during ageing (immunosenescence) by a remodeling of innate immunity (well preserved, up-regulated) and clonotypical immunity (severely altered) and by the occurrence of a chronic inflammatory process (inflammaging) which are, at least in part, genetically controlled. In this scenario, it can be anticipated that a crucial role is played by age-related structural and functional alterations and modifications of proteasomes and immunoproteasomes, the last being a key component of antigen processing and MHC class I antigen presentation. A variety of experimental data are available, suggesting that proteasomes are affected by age, and that in centenarians they are relatively preserved. On the contrary, few data are available on immunoproteasomes, likely as a consequence of the poverty of suitable cellular models. Lymphoblastoid cell lines from EBV immortalized B cells from old donors is envisaged as a possible model for the study of immunoproteasomes in humans and their changes with age. Thus, basic questions such as those related to possible consequences, for immune responses in infectious diseases and cancer, of age-related alterations of antigen processing and presenting, change with age of self-antigen repertoire, and the genetic basis of immunoproteasome activity and its change with age, remain largely unanswered.

Aged↗
PubMed2003

Insulin/IGF-I-signaling pathway: an evolutionarily conserved mechanism of longevity from yeast to humans.

Although the underlying mechanisms of longevity are not fully understood, it is known that mutation in genes that share similarities with those in humans involved in the insulin/insulin-like growth factor I (IGF-I) signal response pathway can significantly extend life span in diverse species, including yeast, worms, fruit flies, and rodents. Intriguingly, the long-lived mutants, ranging from yeast to mice, share some important phenotypic characteristics, including reduced insulin signaling, enhanced sensitivity to insulin, and reduced IGF-I plasma levels. Such genetic homologies and phenotypic similarities between insulin/IGF-I pathway mutants raise the possibility that the fundamental mechanism of aging may be evolutionarily conserved from yeast to mammals. Very recent findings also provide novel and intriguing evidence for the involvement of insulin and IGF-I in the control of aging and longevity in humans. In this study, we focus on how the insulin/IGF-I pathway controls yeast, nematode, fruit fly, and rodent life spans and how it is related to the aging process in humans to outline the prospect of a unifying mechanism in the genetics of longevity.

Aging↗