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M Bonafè

Publications and source records attributed to M Bonafè.

45 records · Page 3Linked to original sources

Age-related changes of the 3'APOB-VNTR genotype pool in ageing cohorts.

The analysis of seven different age cohorts (697 individuals from 10 to 109 years old) revealed age-related changes in the 3'APOB-VNTR genotype pool. By recoding the 3'APOB-VNTR alleles into three size-classes (small, S, 26-34 repeats; medium, M, 35-39 repeats; large, L, 41-55 repeats), an age-related convex trajectory of the frequency of SS homozygotes was found. The frequency of SS in the genotype pool increased from the group aged 10-19 years (3.06 +/- 1.74%) to that aged 40-49 years (8.51 +/- 4.07%). Then it declined reaching the minimum value in centenarians (1.58 +/- 0.90%). The observed trajectory is in agreement with that expected by assuming crossing of mortality curves relevant to subgroups of individuals having different genotypes.

Adolescent↗

Successful immunosenescence and the remodelling of immune responses with ageing.

In recent decades, major theoretical and technological advances have been achieved in the field of immunology. These have allowed the scientific community to analyse the immune system in a much more sophisticated manner than was possible even 20 years ago. Moreover, great theoretical changes have also occurred in gerontology-in particular, the hypothesis has been put forward that ageing and diseases are two different phenomena, and that successful ageing, i.e. ageing in good psychophysical conditions, is really possible for most humans and animals. Immunosenescence was then carefully investigated, either in selected healthy people of advanced age or in the oldest old people, such as healthy centenarians. The main results showed that most immune parameters are indeed well preserved even at this far advanced age. This paper deals with some of the most important theoretical problems of immunosenescence. An immunological tenet was that the most important phenomenon of immunosenescence is the involution of the thymus. In most textbooks and papers it is taken for granted that the thymus starts its involution immediately after puberty. When people aged 60-65 were considered old, it was not difficult to think that they could live for the rest of their life with a fully involuted thymus. The findings on centenarians challenge this tenet, as they have only a small reduction of T lymphocytes, and a relatively normal number of virgin and memory T cells, together with a functional T cell repertoire. Other observations reported here on centenarians, concerning the activity of B lymphocytes and the cytokine network, as well as those on the well-preserved innate immunity and the cells' capability of undergoing proliferation after appropriate stimuli, suggest that complex immune changes occur with age, but also indicate that we have to modify our attitude, to grasp the new scenario which is emerging. Immunosenescence can no longer be considered as a unidirectional deterioration, and this complex phenomenon is much better described by terms such as 'remodelling', 'reshaping' or 'retuning'.

Aging↗

M-07e cell bioassay detects stromal cell production of granulocyte-macrophage colony stimulating factor and stem cell factor in normal and in Diamond-Blackfan anemia bone marrow.

Ten healthy donors and four patients with Diamond-Blackfan anemia (DBA) have been investigated for granulocyte-macrophage colony stimulating factor (GM-CSF) and stem cell factor (SCF) production by bone marrow-enriched fibroblasts (BMEF) in a highly sensitive biological assay on growth factor-dependent M-07e cells. M-07e cells detected active soluble kit-ligand from normal bone marrow fibroblasts as well as from DBA BMEF which produce constitutively significant amounts of SCF. Interleukin 1 beta (IL-1 beta) induced a significant increase of soluble SCF from both normal and DBA BMEF. GM-CSF was undetectable in unstimulated cultures, while its production by bone marrow microenvironmental cells was documented for both normal and DBA patients after IL-1 beta stimulation in vitro.

Adult↗

Production of interleukin 6, leukemia inhibitory factor and granulocyte-macrophage colony stimulating factor by peripheral blood mononuclear cells in Fanconi's anemia.

The aim of this study was to test the in vitro cytokine production by peripheral blood mononuclear cells (PBMCs) in patients with Fanconi's anemia (FA). Phytohemagglutinin (PHA)-stimulated PBMCs from 21 patients with FA were studied for their ability to produce interleukin 6 (IL-6), leukemia inhibitory factor (LIF) and granulocyte-macrophage colony stimulating factor (GM-CSF). Enzymatic immunoassay (EIA) was used for both IL-6 and LIF, while GM-CSF was evaluated in a highly sensitive biological assay provided by GM-CSF-dependent M-07e cells. A significant decrease of IL-6 was detected in 9 out of 11 FA patients compared with five normal donors, while similar amounts of LIF were produced from 21 FA patients and 21 healthy subjects. A drastic increase of active GM-CSF was documented in PHA-stimulated PBMC-conditioned medium in all 18 FA patients tested. Since IL-6 and GM-CSF play an important role in maintaining basal hemopoiesis, our results suggest that an abnormal cytokine network may be involved in the pathogenesis of FA pancytopenia.

Adolescent↗

Age dependent impact of LMP polymorphisms on TNFalpha-induced apoptosis in human peripheral blood mononuclear cells.

As a consequence of inflammatory stimuli (such as TNFalpha and IFNgamma), some constitutive subunits of the proteasome, the principal mediator of nonlysosomal protein degradation, are replaced with other subunits, the large multifunctional proteases LMP2 and LMP7, thus originating the immunoproteasome. An age-related alteration of proteasome activity and susceptibility to TNFalpha-induced apoptosis, in which LMP2 and the nuclear factor (NF)-kappaB activation play an important role has been recently reported. In this paper, we investigated the possible influence of two LMP2 and LMP7 polymorphisms on susceptibility to TNFalpha-induced apoptosis. Our data show that an increase in susceptibility to TNFalpha-induced apoptosis is evident in long-lived people (aged >88 years) in comparison to young individuals. Moreover, the modulation of LMP2 codon 60 polymorphism on TNFalpha-induced apoptosis is evident in long-lived subjects. Genotyping of 311 young people and 157 nonagenarians and centenarians revealed no changes in LMP2 codon 60 genotype frequency distribution. No correlation with TNFalpha-induced apoptosis and no difference in frequency between young people and nonagenarians/centenarians was observed when the LMP7 nucleotide 145 polymorphism was studied.

Adult↗

Gene/longevity association studies at four autosomal loci (REN, THO, PARP, SOD2).

The possibility that four loci (REN, THO, PARP, SOD2) are associated with longevity was explored by comparing the genotypic pools of subjects older than 100 years with those of younger subjects matched for sex and geographic area (northern and southern Italy). The markers (all located within the respective gene) were HUMREN4; HUMTHO1; HUMPARP (gt)845nt; SOD2(C/T)401nt. In order to reduce the number of genotypes, multiallelic polymorphisms were recoded as diallelic according to allele size and frequency patterns (small: S, and large: L, alleles). A significant loss of LL homozygous genotypes was found at the THO locus in male but not in female centenarians with respect to matched controls. On the other hand no significant difference was found between case/control genotypic frequencies at REN, PARP, SOD2 loci. The latter loci therefore do not affect inter-individual variability in life expectancy (at least in terms of qualitative variants associated with the tested markers). However, the data is consistent with an association between the THO locus and longevity.

Adolescent↗

Metabolic gene polymorphisms and p53 mutations in healthy centenarians and younger controls.

To obtain insights into the genetic mechanisms of ageing, we studied the frequency of the simultaneous presence of polymorphisms in phase I and phase II genes and of several p53 germline mutations in a group of 66 nonagenarians and centenarians in good health, selected from a larger sample of a multicentre Italian study in Northern Italy, and in a sample of 150 young healthy volunteers of the same ethnic group. We found a statistically significant difference in the frequency of 1the GSTT1 deletion and the p53 genotypes: the absence of any p53 polymorphisms and of GSTT1 deletion, and the simultaneous presence of the three p53 polymorphisms and of GSTT1 deletion, were much more frequent in young subjects than in centenarians (41.5% versus 26.9% and 8.8% versus 3.8%, respectively). One hypothesis to explain this difference is that subjects with both GSTT1 deletion and p53 polymorphisms may accumulate carcinogens and may have reduced DNA repair ability, and thus are more at risk for cancer. Another possible explanation is that both metabolic genes and p53 act on pathways related to cell ageing and death, and therefore certain composite genetic patterns could represent a generic mechanism of protection against ageing, not just against the development of chronic diseases. It is likely that longevity is related to a complex genetic trait as well as to certain environmental exposures.

Adult↗