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.
Long-living individuals (LLIs) are used to study exceptional longevity. A number of genetic variants have been found associated in LLIs to date, but further identification of variants would improve knowledge on the mechanisms regulating the rate of aging. Therefore, we performed a genome-wide association study on 410 LLIs and 553 young control individuals with a 317K single-nucleotide polymorphism (SNP) chip to identify novel traits associated with aging. Among the top (p < 1 × 10(-4)) SNPs initially identified, we found rs10491334 (CAMKIV) (odds ratio [OR] = 0.55; 95% confidence interval [CI] 0.42-0.73; p = 2.88 × 10(-5)), a variant previously reported associated with diastolic blood pressure, associated also in a replication set of 116 LLIs and 160 controls (OR = 0.54; 95% CI 0.32-0.90; p = 9 × 10(-3)). Furthermore, in vitro analysis established that calcium/calmodulin-dependent protein kinase IV (CAMKIV) activates the survival proteins AKT, SIRT1, and FOXO3A, and we found that homozygous carriers of rs10491334 have a significant reduction in CAMKIV expression. This, together with the observed reduction in minor-allele carriers among centenarians, points to a detrimental role for the SNP. In conclusion, prolongevity genes are activated by CAMKIV, the levels of which are influenced by rs10491334, a SNP associated with human longevity.
Aging is the sum of the deleterious changes that occur as time goes by. It is the main risk factor for the development of cardiovascular disease, and aging of the vasculature is the event that most often impacts on the health of elderly people. The “free-radical theory of aging” was proposed to explain aging as a consequence of the accumulation of reactive oxygen species (ROS). However, recent findings contradict this theory, and it now seems that mechanisms mediating longevity act through induction of oxidative stress. In fact, calorie restriction − a powerful way of delaying aging − increases ROS accumulation due to stimulation of the basal metabolic rate; moreover, reports show that antioxidant therapy is detrimental to healthy aging. We also now know that genetic manipulation of the insulin-like-growth-factor-1/insulin signal (IIS) has a profound impact on the rate of aging and that the IIS is modulated by calorie restriction and physical exercise. The IIS regulates activation of nitric oxide synthase (eNOS), the activity of which is essential to improving lifespan through calorie restriction, as demonstrated by experiments on eNOS knockout mice. Indeed, eNOS has a key role in maintaining vascular integrity during aging by activating vasorelaxation and allowing migration and angiogenesis. In this review, we will overview current literature on these topics and we will try to convince the reader of the importance of vascular integrity and nitric oxide production in determining healthy aging.
BackgroundPeople 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.MethodsWestern 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.ResultsHere 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.ConclusionsSerum 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.
In amyotrophic lateral sclerosis (ALS), there is selective degeneration of motor neurons that leads to paralysis and death. Although the etiology of ALS is unclear, its heterogeneity suggests that a combination of factors (endogenous and/or environmental) may induce progressive motor neuron stress that results in the activation of different cell death pathways. Alterations of brain cholesterol homeostasis have recently been considered as possible cofactors in many neurodegenerative disorders, including ALS. The liver X receptor beta (LXRbeta) receptor is involved in lipogenesis and cholesterol metabolism, and we previously found that adult-onset motor neuron pathology occurs in LXRbeta mice. Here, we investigated neuromuscular alterations of LXRbeta mice from ages 3 to 24 months. Increased cholesterol levels, gliosis, and inflammation preceded motor neuron loss and clinical disease onset; the mice showed progressivemotor neuron deficits starting from age 7 months. The numbers ofmotor neurons and neuromuscular junctions were decreased in 24-month-old mice, but neither paralysis nor reduced life span was observed. Moreover, other spinal neurons were also lost in these mice. These results suggest that LXRbeta may inhibit neuroinflammation and maintain cholesterol homeostasis, and that LXRbeta mice represent a potential model for investigating the role of cholesterol in ALS and other neurodegenerative disorders.
AimsAgeing 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.Methods and resultsLAV-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).ConclusionsWe 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.
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