Biomedical subjects

Stefano Salvioli

Publications and source records attributed to Stefano Salvioli.

17 recordsLinked to original sources

PubMed2006

Inflammaging and anti-inflammaging: a systemic perspective on aging and longevity emerged from studies in humans.

A large part of the aging phenotype, including immunosenescence, is explained by an imbalance between inflammatory and anti-inflammatory networks, which results in the low grade chronic pro-inflammatory status we proposed to call inflammaging. Within this perspective, healthy aging and longevity are likely the result not only of a lower propensity to mount inflammatory responses but also of efficient anti-inflammatory networks, which in normal aging fail to fully neutralize the inflammatory processes consequent to the lifelong antigenic burden and exposure to damaging agents. Such a global imbalance can be a major driving force for frailty and common age-related pathologies, and should be addressed and studied within an evolutionary-based systems biology perspective. Evidence in favor of this conceptualization largely derives from studies in humans. We thus propose that inflammaging can be flanked by anti-inflammaging as major determinants not only of immunosenescence but eventually of global aging and longevity.

Aging↗

PubMed2006

Resistance to apoptosis of HCW-2 cells can be overcome by curcumin- or vincristine-induced mitotic catastrophe.

The term mitotic catastrophe has recently become widely used to describe a form of death affecting many cancer cells, which, because of severe DNA or mitotic spindle damage, are not able to bypass mitosis. We show here that cells of the HL-60-derived HCW-2 line highly resistant to apoptosis, upon treatment with curcumin or vincristine, undergo mitotic catastrophe that is finalized by caspase 3 activation and oligonucleosomal DNA degradation. Curcumin is a natural dye, derived from Curcuma longa that has been shown to induce cell death in many cancer cells. Both treatments decrease cell proliferation and cell survival, arrest cells in G2/M phase of cell cycle and induce morphological changes characterized by cell enlargement and micronucleation. "Catastrophic" cells comprise a separate subpopulation with less than 4C DNA, as evidenced by flow and scanning cytometry. This subpopulation is MPM-2 positive. Thymidine block increased the number of cell arrested in the G2/M phase of cell cycle and curcumin effectiveness as an inducer of mitotic catastrophe. Curcumin, but not vincristine, acts on HCW-2 cells by inhibiting the expression of survivin, a modulator of cell division and apoptosis in cancer. Altogether our results show that apoptosis resistance can be overcome by inducing mitotic catastrophe in HCW-2 cells.

Apoptosis↗

PubMed2006

Mitochondrial DNA involvement in human longevity.

The main message of this review can be summarized as follows: aging and longevity, as complex traits having a significant genetic component, likely depend on a number of nuclear gene variants interacting with mtDNA variability both inherited and somatic. We reviewed the data available in the literature with particular attention to human longevity, and argued that what we hypothesize for aging and longevity could have a more general relevance and be extended to other age-related complex traits such as Alzheimer's and Parkinson's diseases. The genetics which emerges for complex traits, including aging and longevity, is thus even more complicated than previously thought, as epistatic interactions between nuclear gene polymorphisms and mtDNA variability (both somatic and inherited) as well as between mtDNA somatic mutations (tissue specific) and mtDNA inherited variants (haplogroups and sub-haplogroups) must be considered as additional players capable of explaining a part of the aging and longevity phenotype. To test this hypothesis is one of the main challenge in the genetics of aging and longevity in the next future.

Cell Nucleus↗

PubMed2006

p66(Shc) gene has a pro-apoptotic role in human cell lines and it is activated by a p53-independent pathway.

p66(Shc) protein has been proposed to be an indispensable factor for p53-dependent, mitochondria-mediated apoptosis in mice. Here, we show that p66(Shc) plays a pro-apoptotic role also in cell lines of human origin such as SaOs-2 and HeLa, where p53 is either absent or inactivated, thus, suggesting that p66(Shc) pro-apoptotic role is independent from the presence of a functional form of p53. The active form of p66(Shc) is phosphorylated in Serine 36. We confirm the importance of Serine 36 phosphorylation for p66(Shc) pro-apoptotic role, and our results suggest that the kinase involved in this process is activated independently from p53.

Adaptor Proteins, Signal Transducing↗

PubMed2006

Gene expression of cytokines and cytokine receptors is modulated by the common variability of the mitochondrial DNA in cybrid cell lines.

Some lines of evidence indicate that common polymorphisms of mitochondrial DNA (mtDNA) act as susceptibility factors in complex traits, such as age-related common diseases. There is also evidence that the cell capability to compensate ravages caused by intrinsic or extrinsic stress factors could contribute to some of these diseases. The cross-talk between nuclear and mitochondrial genome may link the above observations if we assume that the transcription of stress-responder nuclear genes is modulated according to the mtDNA common variability. Cytokines and cytokine receptors are key molecules in stress response. We could, therefore, check the above hypothesis by analyzing expression patterns of cytokine and cytokine receptor genes in response to stress in cell lines sharing the same nuclear genome but different mtDNA. By using a cybrid model (143B.TK- osteosarcoma cells depleted of their own mtDNA and repopulated with foreign mitochondria) we show that the transcription patterns of some of such genes are specifically modulated by the variability of the mitochondrial genome not only under stress conditions (interleukin-6) but also at basal conditions (interleukin-1beta and tumor necrosis factor receptor 2). These findings provide a first experimental evidence of a relationship between mtDNA common variability and expression pattern of stress responder nuclear genes in human cells.

Cell Fusion↗

PubMed2006

Complexity of anti-immunosenescence strategies in humans.

Immunosenescence is characterized by three main aspects: (i) the shrinkage of the T cell repertoire and the accumulation of oligoclonal expansions (megaclones) of memory/effector cells directed toward ubiquitary infectious agents; (ii) the involution of the thymus and the exhaustion of naïve T cells; and (iii) a chronic inflammatory status called inflamm-aging. We present here possible strategies to counteract these main aspects of immunosenescence in humans with particular attention to the reduction of antigenic load by pathogens, such as CMV, and the normalization of intestinal microflora, the possible utilization of IL-7 to reverse thymic involution, the purging of megaclones, the forced expression of CD28 on T lymphocytes, the reduction of inflamm-aging and the administration of nutrients such as vitamin D. Possible drawbacks of all these strategies are discussed. Finally, the complexity of a rejuvenation approach is stressed, with particular attention to the inhibitory role played by the "old microenvironment" on the performance of progenitor cells, the best candidate to counteract the decline in regenerative potential characteristic of organs and tissues from old organisms.

Aging↗

PubMed2006

The genetics of human longevity.

Aging is due to a complex interaction of genetic, epigenetic, and environmental factors, but a strong genetic component appears to have an impact on survival to extreme ages. In order to identify "longevity genes" in humans, different strategies are now available. In our laboratory, we performed association studies on a variety of "candidate" polymorphisms in Italian centenarians. Many genes/polymorphisms gave negative results, while others showed a positive association with human longevity and a sometimes-positive association with unsuccessful aging (myocardial infarction, Alzheimer's disease, and type 2 diabetes). Results regarding genes involved in inflammation (IL-1 cluster, IL-6, IL-10, TNF-alpha, TGF-beta, TLR-4, PPARgamma), insulin/IGF-1 signaling pathway and lipid metabolism (apolipoproteins, CETP, PON1), and oxidative stress (p53, p66(shc)) will be described. In addition, a strong role of the interaction between nuclear and mitochondrial genomes (mtDNA haplogroups and the C150T mutation) emerged from our findings. Thus, the genetics of human longevity appears to be quite peculiar in a context where antagonistic pleiotropy can play a major role and genes can have a different biological role at different ages.

Adaptor Proteins, Signal Transducing↗

PubMed2006

Age-dependent effects of in vitro radiofrequency exposure (mobile phone) on CD95+ T helper human lymphocytes.

Recent studies on "nonthermal" effects of mobile phone radiofrequency (RF) suggest that RF can interact with cellular functions and molecular pathways. To study the possible RF effects on human lymphocyte activation, we analyzed CD25, CD95, CD28 molecules in unstimulated and stimulated CD4+ e CD8+ T cells in vitro. Peripheral blood mononuclear cells (PBMCs) from young and elderly donors were exposed or sham-exposed to RF (1,800 MHz, Specific Absorption Rate 2 W/kg) with or without mitogenic stimulation. No significant changes in the percentage of these cell subsets were found between exposed and sham-exposed lymphocytes in both young and elderly donors. Nevertheless, after RF exposure we observed a slight, but significant, downregulation of CD95 expression in stimulated CD4+ T lymphocytes from elderly, but not from young donors. This age-related result is noteworthy given the importance of a such molecule in regulation of the immune response.

Adult↗

PubMed2006

A structural model of 20S immunoproteasomes: effect of LMP2 codon 60 polymorphism on expression, activity, intracellular localisation and insight into the regulatory mechanisms.

The immunoproteasome subunit low molecular weight protein 2 (LMP2) codon 60 polymorphism has been associated with autoimmune diseases. It has also been demonstrated to influence susceptibility to TNF-alpha-induced apoptosis in blood cells and proteasome activity in aged human brain. In the present study, an in silico model of immunoproteasome was used to examine the effect of the R60H polymorphism in the LMP2 subunit. The investigation of immunoproteasome expression, activity and intracellular localisation in an in vitro cellular model, namely lymphoblastoid cell lines, showed no major variations in functionality and amount, while a significant difference in antibody affinity was apparent. These data were integrated with previous results obtained in different tissues and combined with a structural model of the LMP2 polymorphism. Accordingly, we identified three prospective mechanisms that could explain the biological data for the polymorphism, such as modulation of the binding affinity of a putative non-catalytic modifier site on the external surface of the immunoproteasome core, or the modification of any channel between alpha and beta rings.

Antibodies, Monoclonal↗

PubMed2005

p53 codon 72 alleles influence the response to anticancer drugs in cells from aged people by regulating the cell cycle inhibitor p21WAF1.

A common polymorphism at codon 72 in p53 gene leads to an arginine to proline aminoacidic substitution which affects in an age-dependent manner the susceptibility of cells to undergo apoptosis after oxidative stress. Here we report that dermal fibroblasts from Proline allele carriers (Pro+) display a higher expression of p21WAF1 gene, in both basal conditions and after treatment with doxorubicin or camptothecin. This phenomenon is accompanied by a lower susceptibility of Pro+ cells to undergo apoptosis, a lower capability to over cross G1-S transition and an increased propensity to express markers of cell senescence, with respect to fibroblasts from Arginine homozygotes (Pro-). All these phenomena are particularly evident in cells from centenarians. We conclude that the functional difference between the two p53 codon 72 alleles exerts a broad impact on the capability of cell from aged people to respond to stressors such as cytotoxic drugs.

Adult↗

PubMed2005

Genes involved in immune response/inflammation, IGF1/insulin pathway and response to oxidative stress play a major role in the genetics of human longevity: the lesson of centenarians.

In this paper, we review data of recent literature on the distribution in centenarians of candidate germ-line polymorphisms that likely affect the individual chance to reach the extreme limit of human life. On the basis of previous observations on the immunology, endocrinology and cellular biology of centenarians we focused on genes that regulate immune responses and inflammation (IL-6, IL-1 cluster, IL-10), genes involved in the insulin/IGF-I signalling pathway and genes that counteract oxidative stress (PON1). On the whole, data indicate that polymorphisms of these genes likely contribute to human longevity, in accord with observations emerging from a variety of animal models, and suggest that a common core of master genes and metabolic pathways are responsible for aging and longevity across animal species. Moreover, in the concern of our plan to discover new genetic factors related to longevity, we explored the possibility to by-pass the need of an a-priori choice of candidate genes, extending the search to genes and genomic regions of still unknown function. Alu sequences may be considered as good markers of highly variable and potentially unstable loci in functionally important genomic regions. We extensively screened Alu-rich genomic sites and found a new genomic region associated with longevity.

Adult↗

PubMed2004

In vitro exposure of human lymphocytes to 900 MHz CW and GSM modulated radiofrequency: studies of proliferation, apoptosis and mitochondrial membrane potential.

The aim of this study was to investigate the nonthermal effects of radiofrequency (RF) fields on human immune cells exposed to a Global System for Mobile Communication (GSM) signal generated by a commercial cellular phone and by a sinusoidal non-modulated signal. To assess whether mobile phone RF-field exposure affects human immune cell functions, peripheral blood mononuclear cells (PBMCs) from healthy donors were exposed in vitro to a 900 MHz GSM or continuous-wave (CW) RF field 1 h/day for 3 days in a transverse electromagnetic mode (TEM) cell system (70-76 mW/kg average specific absorption rate, SAR). The cells were cultured for 48 or 72 h, and the following end points were studied: (1) mitogen-induced proliferation; (2) cell cycle progression; (3) spontaneous and 2-deoxy-D-ribose (dRib)-induced apoptosis; (4) mitochondrial membrane potential modifications during spontaneous and dRib-induced-apoptosis. Data obtained from cells exposed to a GSM-modulated RF field showed a slight decrease in cell proliferation when PBMCs were stimulated with the lowest mitogen concentration and a slight increase in the number of cells with altered distribution of phosphatidylserine across the membrane. On the other hand, cell cycle phases, mitochondrial membrane potential and susceptibility to apoptosis were found to be unaffected by the RF field. When cells were exposed to a CW RF field, no significant modifications were observed in comparison with sham-exposed cells for all the end points investigated.

Adult↗

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

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↗

PubMed2002

p53 codon 72 genotype affects apoptosis by cytosine arabinoside in blood leukocytes.

A wide difference in the susceptibility to undergo in vitro apoptosis exists among individuals, and this fact has potential implications in predicting the in vivo response to apoptotic agents, such as those employed in chemotherapy. In this report, we addressed the question whether the natural variability at p53 locus (the proline-arginine substitution at codon 72) affects the capacity of peripheral-blood mononuclear cells from healthy subjects to undergo in vitro apoptosis in response to the cytotoxic drug cytosine arabinoside. We found that cells from subjects carrying the arginine/arginine genotype undergo in vitro apoptosis at a higher extent in comparison to those from arginine/proline subjects. This finding suggests that naturally occurring genetic variability at p53 gene explains part of the inter-individual difference in the in vitro susceptibility to a chemotherapeutic drug, thus resulting as an eligible predictor marker of in vivo response to chemotherapy and its adverse effects.

Adult↗

PubMed2002

Early changes in intramitochondrial cardiolipin distribution during apoptosis.

Cardiolipin (CL) is essential for the functionality of several mitochondrial proteins. Its distribution between the inner and outer leaflet of the mitochondrial internal membrane is crucial for ATP synthesis. We have investigated alterations in CL distribution during the early phases of apoptosis. Using two classical models (staurosporine-treated HL-60 cells and tumor necrosis factor alpha-treated U937 cells), we found that in apoptotic cells CL moves to the outer leaflet of mitochondrial inner membrane in a time-dependent manner. This occurs before the appearance of apoptosis markers such as plasma-membrane exposure of phosphatidylserine, changes in mitochondrial membrane potential, DNA fragmentation, but after the production of reactive oxygen species. The exposure of a phospholipid on the outer surface during apoptosis thus occurs not only at the plasma membrane level but also in mitochondria, reinforcing the hypothesis of mitoptosis as a crucial regulating system for programmed cell death, also occurring in cancer cells after treatment with antineoplastic agents.

Apoptosis↗

PubMedDate not supplied

What studies on human longevity tell us about the risk for cancer in the oldest old: data and hypotheses on the genetics and immunology of centenarians.

Centenarians are people who escaped from major common diseases, including cancer, and reached the extreme limits of human life-span. The analysis of demographic data indicates that cancer incidence and mortality show a levelling off around the age of 85-90 years, and suggests that oldest old people and centenarians are protected from cancer onset and progression. In this paper, we review data of recent literature on the distribution in centenarians of germ-line polymorphisms, which are supposed to affect the individual susceptibility to cancer (p53, HRAS1, BRCA1, glutathione transferases, cytochrome oxidases, steroid-5 alpha-reductase enzyme type II). Moreover, we add new data on two p53 polymorphisms in a total of 1086 people of different age, including 307 centenarians. In addition, we put forth the hypothesis that the remodelling of the immune system occurring with age is capable of creating a hostile environment for the growth of cancer cells in these exceptional individuals. We conclude that future studies on centenarians regarding the germ-line variability of genes involved in the control of the immune response, including apoptosis (ApoJ), are likely to be of fundamental importance in understanding the basic mechanisms for cancer, aging and their complex relationship.

Adult↗