Rationale:: Long living individuals show delay of aging, which is characterized by the progressive loss of cardiovascular homeostasis, along with reduced endothelial nitric oxide synthase activity, endothelial dysfunction, and impairment of tissue repair after ischemic injury. Objective:: Exploit genetic analysis of long living individuals to reveal master molecular regulators of physiological aging and new targets for treatment of cardiovascular disease. Methods and Results:: We show that the polymorphic variant rs2070325 (Ile229Val) in bactericidal/permeability-increasing fold-containing-family-B-member-4 (BPIFB4) associates with exceptional longevity, under a recessive genetic model, in 3 independent populations. Moreover, the expression of BPIFB4 is instrumental to maintenance of cellular and vascular homeostasis through regulation of protein synthesis. BPIFB4 phosphorylation/activation by protein-kinase-R–like endoplasmic reticulum kinase induces its complexing with 14-3-3 and heat shock protein 90, which is facilitated by the longevity-associated variant. In isolated vessels, BPIFB4 is upregulated by mechanical stress, and its knock-down inhibits endothelium-dependent vasorelaxation. In hypertensive rats and old mice, gene transfer of longevity-associated variant-BPIFB4 restores endothelial nitric oxide synthase signaling, rescues endothelial dysfunction, and reduces blood pressure levels. Furthermore, BPIFB4 is implicated in vascular repair. BPIFB4 is abundantly expressed in circulating CD34 ⁺ cells of long living individuals, and its knock-down in endothelial progenitor cells precludes their capacity to migrate toward the chemoattractant SDF-1. In a murine model of peripheral ischemia, systemic gene therapy with longevity-associated variant-BPIFB4 promotes the recruitment of hematopoietic stem cells, reparative vascularization, and reperfusion of the ischemic muscle. Conclusions:: Longevity-associated variant-BPIFB4 may represent a novel therapeutic tool to fight endothelial dysfunction and promote vascular reparative processes.

Aims: Here, we aimed to determine the therapeutic effect of longevity-associated variant (LAV)-BPIFB4 gene therapy on atherosclerosis. Methods and results: ApoE knockout mice (ApoE−/−) fed a high-fat diet were randomly allocated to receive LAV-BPIFB4, wild-type (WT)-BPIFB4, or empty vector via adeno-associated viral vector injection. The primary endpoints of the study were to assess (i) vascular reactivity and (ii) atherosclerotic disease severity, by Echo-Doppler imaging, histology and ultrastructural analysis. Moreover, we assessed the capacity of the LAV-BPIFB4 protein to shift monocyte-derived macrophages of atherosclerotic mice and patients towards an anti-inflammatory phenotype. LAV-BPIFB4 gene therapy rescued endothelial function of mesenteric and femoral arteries from ApoE−/− mice; this effect was blunted by AMD3100, a CXC chemokine receptor type 4 (CXCR4) inhibitor. LAV-BPIFB4-treated mice showed a CXCR4-mediated shift in the balance between Ly6Chigh/Ly6Clow monocytes and M2/M1 macrophages, along with decreased T cell proliferation and elevated circulating levels of interleukins IL-23 and IL-27. In vitro conditioning with LAV-BPIFB4 protein of macrophages from atherosclerotic patients resulted in a CXCR4-dependent M2 polarization phenotype. Furthermore, LAV-BPIFB4 treatment of arteries explanted from atherosclerotic patients increased the release of atheroprotective IL-33, while inhibiting the release of pro-inflammatory IL-1β, inducing endothelial nitric oxide synthase phosphorylation and restoring endothelial function. Finally, significantly lower plasma BPIFB4 was detected in patients with pathological carotid stenosis (>25%) and intima media thickness >2 mm. Conclusion: Transfer of the LAV of BPIFB4 reduces the atherogenic process and skews macrophages towards an M2-resolving phenotype through modulation of CXCR4, thus opening up novel therapeutic possibilities in cardiovascular disease.

People that reach extreme ages (Long-Living Individuals, LLIs) are object of intense investigation for increase/decrease of genetic variant frequencies, genetic methylation levels, protein abundance in serum and tissues. The aim of these studies is the discovery of the mechanisms behind LLIs extreme longevity and the identification of markers of well-being. We have recently associated a BPIFB4 haplotype (LAV) with exceptional longevity under a homozygous genetic model, and identified that CD34+ of LLIs subjects express higher BPIFB4 transcript as compared to CD34+ of control population. It would be of interest to correlate serum BPIFB4 protein levels with exceptional longevity and health status of LLIs. Western blots on cellular medium to detect BPIFB4 secretion in transfected HEK293T cells with plasmid carrying BPIFB4 and ELISA on LLIs serum to detect BPIFB4 levels. Here we show that BPIFB4 is a secreted protein and its levels are increased in serum of LLIs, and high BPIFB4 levels classify their health status. Serum BPIFB4 protein levels classify longevity and health status in LLIs. Further studies are required to evaluate the possible role of BPIFB4 in monitoring disease progression.

Ageing is associated with impairment of endothelial nitric oxide synthase (eNOS) and progressive reduction in endothelial function. A genetic study on long-living individuals—who are characterized by delays in ageing and in the onset of cardiovascular disease—previously revealed I229V (rs2070325) in bactericidal/permeability-increasing fold-containing-family-B-member-4 (BPIFB4) as a longevity-associated variant (LAV); the LAV protein enhanced endothelial NO production and vasorelaxation through a protein kinase R–like endoplasmic reticulum kinase/14-3-3/heat shock protein 90 signal. Here, we further characterize the molecular mechanisms underlying LAV-BPIFB4-dependent enhancement of vascular function. LAV-BPIFB4 upregulated eNOS function via mobilization of Ca²⁺ and activation of protein kinase C alpha (PKCα). Indeed, the overexpression of LAV-BPIFB4 in human endothelial cells enhanced ATP-induced Ca²⁺ mobilization and the translocation of PKCα to the plasma membrane. Coherently, pharmacological inhibition of PKCα blunted the positive effect of LAV-BPIFB4 on eNOS and endothelial function. In addition, although LAV-BPIFB4 lost the ability to activate PKCα and eNOS in ex vivo vessels studied in an external Ca²⁺-free medium and in vessels from eNOS^−/− mice, it still potentiated endothelial activity, recruiting an alternative mechanism dependent upon endothelium-derived hyperpolarizing factor (EDHF). We have identified novel molecular determinants of the beneficial effects of LAV-BPIFB4 on endothelial function, showing the roles of Ca²⁺ mobilization and PKCα in eNOS activation and of EDHF when eNOS is inhibited. These results highlight the role LAV-BPIFB4 can have in restoring signals that are lost during ageing.