Search

Rationale: Endothelial nitric oxide synthase (eNOS) is a crucial enzyme for vascular physiology and its reduced activity during aging leads to increased cardio and cerebrovascular disease susceptibility1-4. Caloric restriction, which delays aging and increases life-span in all species, doesn?t exert any effect in mice lacking eNOS5. Long Living Individuals (LLIs) have a favourable genetic profile, characterized by an enrichment of alleles that protect from aging and cardiovascular disease6, 7. We have recently shown that LLIs of three populations are enriched for the minor allele rs2070325 (I229V) of the bactericidal/permeability-increasing fold-containing family B member 4 (BPIFB4) and that rs2070325 is part of a four SNPs haplotype that codified for a Wild Type (WT) and a longevity- associated variant (LAV) of BPIFB4, that is able to potentiate eNOS activity. This unique ability is correlated with its higher efficiency, as compared to WT-BPIFB4, in binding 14-3-3 through a BPIFB4 atypical binding site for 14-3-3, which correlates with its level of phosphorylation at serine 75, a phosphorylation site for stress kinase PERK. HSP90 recruitment into the complex is part of the eNOS activation machinery triggered by LAV-BPIFB4. Indeed HSP90 is co-immunoprecipitated together with BPIFB4 and a specific HSP90 inhibitor blocks LAV-BPIFB4 potentiation on endothelial function and eNOS activation. The data so far reported clearly demonstrate that LAV-BPIFB4 activates eNOS function trough 14-3-3 and HSP90 recruitment and, as underlined by William Sessa in its editorial, further characterization is needed to define how LAV-BPIFB4 transduce upstream signals to eNOS Objective: To further characterize the molecular signaling regulated by LAV-BPIFB4 to modulate vascular function. Methods and Results: Here we show that eNOS activation by LAV- BPIFB4 is mediated by Ca2+ mobilization and PKC-alpha activation. In LAV-BPIFB4 transfected HEK293 cells, there was an enhancement of ATP- induced Ca2+ mobilization and PKC-alpha translocation on plasma membrane. In vascular reactivity studies, LAV-BPIFB4 failed to potentiate eNOS and endothelial function upon PKC-alpha inhibition by G�6976. Moreover, when vessels were exposed to external Ca2+-free conditions, LAV-BPIFB4 lost the ability to activate PKC-alpha and eNOS. In these conditions, though, and in eNOS knockout vessels, LAV-BPIFB4 still potentiated endothelial activity, through mechanisms alternative to eNOS, and this function was blunted by the inhibitors of the endothelium-derived hyperpolarizing factors (EDHF). Notably, peripheral blood mononuclear cells from subjects carrying the a/a genotype for rs2070325 had a significant increase of phosphorylation of PKC-alpha (T497). Conclusions: We have identified novel molecular determinants of the beneficial effects of LAV-BPIFB4 on endothelial function, showing the role of Ca2+ mobilization and PKC-alpha in eNOS activation and of EDHF activation upon eNOS inhibition. These results highlight the role of LAV- BPIFB4.

Background The aim of this study was to analyse the role of GM allotypes, i.e. the hereditary antigenic determinants expressed on immunoglobulin polypeptide chains, in the attainment of longevity. The role played by immunoglobulin allotypes in the control of immune responses is well known as well as the role of an efficient immune response in longevity achievement. So, it is conceivable that particular GM allotypes may contribute to the generation of an efficient immune response that supports successful ageing, hence longevity. Methods In order to show if GM allotypes play a role in the achievement of longevity, we typed the DNA of 95 Long-living individuals (LLIs) and 96 young control individuals (YCs) from South Italy for GM3/17 and GM23+/− alleles. Results To demonstrate the role of GM allotypes in the attainment of longevity we compared genotype and allele frequencies of GM allotypes between LLIs and YCs. A global chi-square test (3 × 2) shows that the distribution of genotypes at the GM 3/17 locus is highly significantly different in LLIs from that observed in YCs (p

BPIFB4 is associated with exceptional longevity: four single-nucleotide polymorphisms distinguish the wild-type form from a longevity-associated variant conferring positive effects on blood pressure. The effect of a rare variant (RV; allele frequency, 4%) on blood pressure is unknown. Here, we show that overexpression of RV-BPIFB4 in ex-vivo mouse vessels impairs phosphorylation of endothelial nitric oxide synthase (eNOS), blunting acetylcholine-evoked vasorelaxation; in vivo, virally mediated overexpression of RV-BPIFB4 increases blood pressure, an action absent in eNOS-deficient mice. In humans, we found RV carriers to have increased diastolic blood pressure, a finding that was more marked in subjects on anti-hypertensive medication; moreover, recombinant RV-BPIFB4 protein impaired eNOS function in ex-vivo human vessels. Thus, RV-BPIFB4 acts directly on blood pressure homeostasis and may represent a novel biomarker of vascular dysfunction and hypertension.

Background Lone atrial flutter (AFL) and atrial fibrillation (AF) are common and sometimes consequential cardiac conduction disorders with a strong heritability, as underlined by recent genome-wide association studies that identified genetic modifiers. Follow-up family-based genetic analysis also identified Mendelian transmission of disease alleles. Three affected members were exome-sequenced for the identification of potential causative mutations, which were subsequently validated by direct sequencing in the other 3 affected members. Taqman assay was then used to confirm the role of any mutation in an independent population of sporadic lone AFL/AF cases. Results The family cluster analysis provided evidence of genetic inheritance of AFL in the family via autosomal dominant transmission. The exome-sequencing of 3 family members identified 7 potential mutations: of these, rs58238559, a rare missense genetic variant in the ATP-binding cassette sub-family B, member 4 (ABCB4) gene was carried by all affected members. Further analysis of 82 subjects with sporadic lone AF, 63 subjects with sporadic lone AFL, and 673 controls revealed that the allele frequency for this variation was significantly higher in cases than in the controls (0.05 vs. 0.01; OR = 3.73; 95% CI = 1.16–11.49; P = 0.013). Conclusions rs58238559 in ABCB4 is a rare missense variant with a significant effect on the development of AFL/AF. Electronic supplementary material The online version of this article (doi:10.1186/s12863-015-0177-0) contains supplementary material, which is available to authorized users.