Lipoproteins, vascular-related genetic factors, and human longevity

Gut Microbiota and Aging: Traditional Chinese Medicine and Modern Medicine

The changing composition of gut microbiota, much like aging, accompanies people throughout their lives, and the inextricable relationship between both has recently attracted extensive attention as well. Modern medical research has revealed that a series of changes in gut microbiota are involved in the aging process of organisms, which may be because gut microbiota modulates aging-related changes related to innate immunity and cognitive function. At present, there is no definite and effective method to delay aging. However, Nobel laureate Tu Youyou's research on artemisinin has inspired researchers to study the importance of Traditional Chinese Medicine (TCM). TCM, as an ancient alternative medicine, has unique advantages in preventive health care and in treating diseases as it already has formed an independent understanding of the aging system. TCM practitioners believe that the mechanism of aging is mainly deficiency, and pathological states such as blood stasis, qi stagnation and phlegm coagulation can exacerbate the process of aging, which involves a series of organs, including the brain, kidney, heart, liver and spleen. Our current understanding of aging has led us to realise that TCM can indeed make some beneficial changes, such as the improvement of cognitive impairment. However, due to the multi-component and multi-target nature of TCM, the exploration of its mechanism of action has become extremely complex. While analysing the relationship between gut microbiota and aging, this review explores the similarities and differences in treatment methods and mechanisms between TCM and Modern Medicine, in order to explore a new approach that combines TCM and Modern Medicine to regulate gut microbiota, improve immunity and delay aging.

Anti-ageing active ingredients from herbs and nutraceuticals used in traditional Chinese medicine: pharmacological mechanisms and implications for drug discovery

Ageing, an unanswered question in the medical field, is a multifactorial process that results in a progressive functional decline in cells, tissues and organisms. Although it is impossible to prevent ageing, slowing down the rate of ageing is entirely possible to achieve. Traditional Chinese medicine (TCM) is characterized by the nourishing of life and its role in anti-ageing is getting more and more attention. This article summarizes the work done on the natural products from TCM that are reported to have anti-ageing effects, in the past two decades. The effective anti-ageing ingredients identified can be generally divided into flavonoids, saponins, polysaccharides, alkaloids and others. Astragaloside, Cistanche tubulosa acteoside, icariin, tetrahydrocurcumin, quercetin, butein, berberine, catechin, curcumin, epigallocatechin gallate, gastrodin, 6-Gingerol, glaucarubinone, ginsenoside Rg1, luteolin, icarisid II, naringenin, resveratrol, theaflavin, carnosic acid, catalpol, chrysophanol, cycloastragenol, emodin, galangin, echinacoside, ferulic acid, huperzine, honokiol, isoliensinine, phycocyanin, proanthocyanidins, rosmarinic acid, oxymatrine, piceid, puerarin and salvianolic acid B are specified in this review. Simultaneously, chemical structures of the monomers with anti-ageing activities are listed, and their source, model, efficacy and mechanism are also described. The TCMs with anti-ageing function are classified according to their action pathways, including the telomere and telomerase, the sirtuins, the mammalian target of rapamycin, AMP-activated kinase and insulin/insulin-like growth factor-1 signalling pathway, free radicals scavenging and the resistance to DNA damage. Finally, Chinese compound prescription and extracts related to anti-ageing are introduced, which provides the basis and the direction for the further development of novel and potential drugs.

LINKED ARTICLES

This article is part of a themed section on Principles of Pharmacological Research of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.11/issuetoc.

Atorvastatin Therapy Modulates Telomerase Activity in Patients Free of Atherosclerotic Cardiovascular Diseases

Background: Telomerase activity (TA) is considered as the biomarker for cardiovascular aging and cardiovascular diseases (CVDs). Recent studies suggest a link between statins and telomere biology that may be explained by anti-inflammatory actions of statins and their positive effect on TA. Until now, this effect has not been investigated in prospective randomized studies. We hypothesized that 12 months of atorvastatin therapy increased TA in peripheral blood mononuclear cells. Methods: In a randomized, placebo-controlled study 100 hypercholesterolemic patients, aged 35-75 years, free of known CVDs and diabetes mellitus type 2 received 20 mg of atorvastatin daily or placebo for 12 months. TA was measured by quantitative polymerase chain reaction. Results: At study end, 82 patients had sufficient peripheral blood mononuclear cells needed for longitudinal analysis. TA expressed as natural logarithms changed from 0.46 ± 0.05 to 0.68 ± 0.06 (p = 0.004) in the atorvastatin group and from 0.67 ± 0.06 to 0.60 ± 0.07 (p = 0.477) in the control group. In multiple regression analysis, atorvastatin therapy was the only independent predictor (p = 0.05) of the changes in TA independently of markers of chronic inflammation and oxidative stress. Atorvastatin therapy was associated with increases in interleukin-6 within the normal range and a tendency toward reduction in blood urea. Conclusion: These initial observations suggest atorvastatin can act as telomerase activator and potentially as effective geroprotector. Trial registration: The trial was registered in ISRCTN registry ISRCTN55050065.

Evidence-based assessment of lipoprotein(a) as a risk biomarker for cardiovascular diseases - Some answers and still many questions

The present article is aimed at outlining the current state of knowledge regarding the clinical value of lipoprotein(a) (Lp(a)) as a marker of cardiovascular disease (CVD) risk by summarizing the results of recent clinical studies, meta-analyses and systematic reviews. The literature supports the predictive value of Lp(a) on CVD outcomes, although the effect size is modest. Lp(a) would also appear to have an effect on cerebrovascular outcomes, however the effect appears even smaller than that for CVD outcomes. Consideration of apolipoprotein(a) (apo(a)) isoforms and LPA genetics in relation to the simple assessment of Lp(a) concentration may enhance clinical practice in vascular medicine. We also describe recent advances in Lp(a) research (including therapies) and highlight areas where further research is needed such as the measurement of Lp(a) and its involvement in additional pathophysiological processes.

Lipoprotein (a): impact by ethnicity and environmental and medical conditions

Levels of lipoprotein (a) [Lp(a)], a complex between an LDL-like lipid moiety containing one copy of apoB, and apo(a), a plasminogen-derived carbohydrate-rich hydrophilic protein, are primarily genetically regulated. Although stable intra-individually, Lp(a) levels have a skewed distribution inter-individually and are strongly impacted by a size polymorphism of the LPA gene, resulting in a variable number of kringle IV (KIV) units, a key motif of apo(a). The variation in KIV units is a strong predictor of plasma Lp(a) levels resulting in stable plasma levels across the lifespan. Studies have demonstrated pronounced differences across ethnicities with regard to Lp(a) levels and some of this difference, but not all of it, can be explained by genetic variations across ethnic groups. Increasing evidence suggests that age, sex, and hormonal impact may have a modest modulatory influence on Lp(a) levels. Among clinical conditions, Lp(a) levels are reported to be affected by kidney and liver diseases.

Computationally Modeling Lipid Metabolism and Aging: A Mini-review

One of the greatest challenges in biology is to improve the understanding of the mechanisms which underpin aging and how these affect health. The need to better understand aging is amplified by demographic changes, which have caused a gradual increase in the global population of older people. Aging western populations have resulted in a rise in the prevalence of age-related pathologies. Of these diseases, cardiovascular disease is the most common underlying condition in older people. The dysregulation of lipid metabolism due to aging impinges significantly on cardiovascular health. However, the multifaceted nature of lipid metabolism and the complexities of its interaction with aging make it challenging to understand by conventional means. To address this challenge computational modeling, a key component of the systems biology paradigm is being used to study the dynamics of lipid metabolism. This mini-review briefly outlines the key regulators of lipid metabolism, their dysregulation, and how computational modeling is being used to gain an increased insight into this system.

Genetic variants influencing human aging from late-onset Alzheimer's disease (LOAD) genome-wide association studies (GWAS)

Genetics plays a crucial role in human aging with up to 30% of those living to the mid-80s being determined by genetic variation. Survival to older ages likely entails an even greater genetic contribution. There is increasing evidence that genes implicated in age-related diseases, such as cancer and neuronal disease, play a role in affecting human life span. We have selected the 10 most promising late-onset Alzheimer's disease (LOAD) susceptibility genes identified through several recent large genome-wide association studies (GWAS). These 10 LOAD genes (APOE, CLU, PICALM, CR1, BIN1, ABCA7, MS4A6A, CD33, CD2AP, and EPHA1) have been tested for association with human aging in our dataset (1385 samples with documented age at death [AAD], age range: 58-108 years; mean age at death: 80.2) using the most significant single nucleotide polymorphisms (SNPs) found in the previous studies. Apart from the APOE locus (rs2075650) which showed compelling evidence of association with risk on human life span (p = 5.27 × 10(-4)), none of the other LOAD gene loci demonstrated significant evidence of association. In addition to examining the known LOAD genes, we carried out analyses using age at death as a quantitative trait. No genome-wide significant SNPs were discovered. Increasing sample size and statistical power will be imperative to detect genuine aging-associated variants in the future. In this report, we also discuss issues relating to the analysis of genome-wide association studies data from different centers and the bioinformatic approach required to distinguish spurious genome-wide significant signals from real SNP associations.

Evaluation of new and established age-related macular degeneration susceptibility genes in the Women's Health Initiative Sight Exam (WHI-SE) Study

PURPOSE

To assess whether established and newly reported genetic variants, independent of known lifestyle factors, are associated with the risk of age-related macular degeneration (AMD) among women participating in the Women's Health Initiative Sight Exam (WHI-SE) Genetic Ancillary Study.

DESIGN

Multicenter case-control study.

METHODS

One hundred and forty-six women with intermediate and late stages of AMD and 1269 subjects without AMD underwent ocular examinations and fundus photography to determine stage of AMD. Fourteen polymorphisms at or near 11 genes, including previously confirmed genes CFH, ARMS2/HTRA1, C2, C3, and CFI; recently reported AMD genes in the high-density lipoprotein cholesterol (HDL) pathway LIPC, ABCA1, CETP, and LPL; TIMP3/SYN3, a known ocular gene recently linked with AMD; and APOE, were assessed using logistic regression analysis.

RESULTS

After adjustment for demographic, behavioral, and other genetic factors, a protective effect was detected among TT carriers compared with non-carriers for the HDL pathway gene, LIPC rs493258, for intermediate and late AMD (OR [95% confidence interval]: 0.3 [0.2-0.7], P = .003). Variants in CFH rs1410996, ARMS2/HTRA1 A69S, and C3 R102G were significantly associated with an increased risk of AMD. Individuals with the homozygous CFI rs10033900 TT genotype had a 2.9 [1.2-7.2]-fold increased risk, and those with the CFH Y402H GG genotype had a 2.2 [1.0-4.8]-fold higher risk of developing AMD compared with non-carriers. APOE4 carriers may have a reduced risk of intermediate/late AMD (OR = 0.5 [0.3-0.9], P = .015. Suggestive associations were seen between AMD and the HDL pathway genes CETP and LPL.

CONCLUSION

In this unique national cohort of women, we found associations with established AMD-related genetic factors and the recently reported LIPC gene in the HDL pathway. These findings may help develop novel therapeutic targets to treat or delay the onset of the disease.

Angiotensin-converting enzyme (ACE) genotypes and disability in hospitalized older patients

The association between angiotensin-converting enzyme (ACE) genotypes and functional decline in older adults remains controversial. To assess if ACE gene variations influences functional abilities at older age, the present study explored the association between the common ACE insertion/deletion (I/D) polymorphism and disability measured with activities of daily living (ADL) in hospitalized older patients. We analyzed the frequency of the ACE genotypes (I/I, I/D, and D/D) in a population of 2,128 hospitalized older patients divided according to presence or absence of ADL disability. Logistic regression analysis adjusted for possible confounding factors, identified an association between the I/I genotype with ADL disability (OR=1.54, 95% CI 1.04-2.29). This association was significant in men (OR=2.01, 95% CI 1.07-3.78), but not in women (OR=1.36, 95% CI 0.82-2.25). These results suggested a possible role of the ACE polymorphism as a genetic marker for ADL disability in hospitalized older patients.

APOE haplotypes are associated with human longevity in a Central Italy population: evidence for epistasis with HP 1/2 polymorphism

BACKGROUND

Apolipoprotein E (APOE) functional haplotypes determined by rs429358 and rs7412 SNPs have been extensively studied and found to be one of the most consistent association in human longevity studies. However, the search for longevity-determining genes in human has largely neglected the operation of genetic interactions.

METHODS

APOE haplotypes have been determined for 1072 unrelated healthy individuals from Central Italy, 18-106 years old, divided into three gender-specific age classes defined according to demographic information and accounting for the different survival between sexes. The epistasis between APOE haplotypes and Haptoglobin (HP) 1/2 polymorphism was tested according to three-way contingency table analysis by a log-linear model.

RESULTS

APOE genotype and haplotype distributions differ significantly along the age classes (Genotype: p=0.014; Haplotype: p=0.005) with APOE*ε4 genotype status and haplotype displaying negative association (Genotype: O.R.=0.377, p=0.002, Haplotype: O.R.=0.447, p=0.005). A significant interaction between APOE*ε4 genotype status, HP 1/2 genotype and age classes is reported (p=0.006).

CONCLUSION

APOE haplotypes are significantly associated with longevity in our population. Of note, HP*1/*1 genotype seems to protects APOE*ε4 carriers from age-related negative selection. Collectively, these results also suggest and claim for further investigations on APOE/HP interaction in other age-related diseases such as Alzheimer's disease, atherosclerosis and Parkinson's disease.

Variations in apolipoprotein E frequency with age in a pooled analysis of a large group of older people

Variation in the apolipoprotein E gene (APOE) has been reported to be associated with longevity in humans. The authors assessed the allelic distribution of APOE isoforms ε2, ε3, and ε4 among 10,623 participants from 15 case-control and cohort studies of age-related macular degeneration (AMD) in populations of European ancestry (study dates ranged from 1990 to 2009). The authors included only the 10,623 control subjects from these studies who were classified as having no evidence of AMD, since variation within the APOE gene has previously been associated with AMD. In an analysis stratified by study center, gender, and smoking status, there was a decreasing frequency of the APOE ε4 isoform with increasing age (χ(2) for trend = 14.9 (1 df); P = 0.0001), with a concomitant increase in the ε3 isoform (χ(2) for trend = 11.3 (1 df); P = 0.001). The association with age was strongest in ε4 homozygotes; the frequency of ε4 homozygosity decreased from 2.7% for participants aged 60 years or less to 0.8% for those over age 85 years, while the proportion of participants with the ε3/ε4 genotype decreased from 26.8% to 17.5% across the same age range. Gender had no significant effect on the isoform frequencies. This study provides strong support for an association of the APOE gene with human longevity.

Apolipoprotein E-related all-cause mortality in hospitalized elderly patients

The most common apolipoprotein E (APOE) allelic variation is implicated in many age-related diseases and human longevity with controversial findings. We investigated the effect of APOE gene polymorphism on all-cause mortality in elderly patients taking into consideration the functional disability, cognitive impairment, malnutrition, and the occurrence of common age-related diseases. APOE genotypes were determined in 2,124 geriatric hospitalized patients (46.5% men and 53.5% women; mean age, 78.2 +/- 7.1 years; range, 65-100 years). At hospital admission, all patients underwent a comprehensive geriatric assessment to evaluate functional disability, cognitive status, nutritional status, and comorbidity. The main and secondary diagnoses at hospital discharge were also recorded. Mortality status was evaluated in all patients after a maximum follow-up of 5 years (range, from 1.26 to 5.23 years; median, 2.86 years). During the study period, 671 patients died (32.0%). At hospital admission, these patients showed a significant higher prevalence of cardiovascular diseases (56.3% vs 53.4%; p = 0.007), neoplasias (32.3% vs 13.7%; p < 0.001), and lower prevalence of neurodegenerative diseases (17.7% vs 20.7%; p < 0.001) than survived patients. Moreover, they also showed an higher prevalence of disability (52.0% vs 25.6%; p < 0.001), cognitive impairment (31.0% vs 18.8%; p < 0.001), and malnutrition (74.0% vs 46.1%; p < 0.001) than survived patients. In the overall study population, the APOE epsilon2 allele was significantly associated to neurodegenerative diseases (odds ratio = 0.59; 95% confidence interval (CI), 0.37-0.94). No significant association between the APOE polymorphism and disability, malnutrition, co-morbidity status, and with all-cause mortality was observed. In patients with cardiovascular diseases, however, a decreased risk of all-cause mortality was found in the epsilon2 allele carriers (hazard ratio = 0.56; 95% CI, 0.36-0.88). In this population, APOE allele variants might play a role on cardiovascular disease-related mortality.

Association between platelet endothelial cellular adhesion molecule-1 polymorphisms and atherosclerosis: results of a study on patients from northern Italy

Adhesion of circulating cells to the arterial surface is among the first detectable events in atherogenesis. Cellular adhesion molecules, expressed by the vascular endothelium and by circulating leukocytes, mediate cell recruitment and their transendothelial migration. Platelet endothelial cellular adhesion molecule-1 (PECAM-1), involved in this migration, has been associated with the development of atherosclerosis. Studies have investigated an association between coronary artery disease (CAD) and single-nucleotide polymorphisms (SNPs) located in functionally important domains of the PECAM-1 gene with inconsistent results. Thus, we have analyzed the distribution of V125L, N563S, and G670R SNPs in patients and controls from northern Italy, and also analyzed another functional variant identified in the 5'-untranslated region (UTR) of the PECAM-1 gene (53 G-->A). The polymorphisms of PECAM-1 were genotyped by PCR amplification with sequence-specific primers (PCR-SSP) in 119 controls and 431 CAD patients. Our results demonstrate that genotype and allele frequencies for the 53 G/A polymorphism are significantly different in patients affected by CAD compared to healthy controls, whereas, as regards the V125L and N563S polymorphisms, only the allelic frequency is significantly different. We have shown that there were a significant differences for the 53 G/A and V125L and N563S polymorphisms of PECAM-1 in patients affected by CAD compared to controls. This demonstrates a possible involvement of this gene in contributing to the development of CAD. Therefore, an understanding of the role of the PECAM-1 molecule in this complex mechanism is of pivotal significance in further development of innovative and suitable medical therapies in the future.

Association of apolipoprotein E and angiotensin converting enzyme gene polymorphisms with the multidimensional impairment in older patients

The role of the apolipoprotein E (APOE) and the angiotensin converting enzyme (ACE) polymorphisms on health and functional status deterioration in old age is still undefined. Recently, a Multidimensional Prognostic Index (MPI) for 1-year mortality derived from a Comprehensive Geriatric Assessment (CGA) was developed and validated in hospitalized elderly patients. The aim of this study was to investigate the possible association of the APOE and ACE gene polymorphisms with the multidimensional impairment, as evaluated by the MPI, in older patients. These polymorphisms were assessed in 1894 geriatric inpatients divided into three groups according to their MPI values: MPI-1 low risk (n = 988), MPI-2 moderate risk (n = 671), and MPI-3 severe risk of mortality (n = 235). A slight deviation from Hardy-Weinberg equilibrium was observed for the APOE genotypes. With the increasing of the MPI grade, a significant increase in the frequencies of epsilon4 allele and the ACE D/D genotype was observed. The APOE epsilon4(+) and ACE D/D genotypes were associated with severe MPI grade (APOE epsilon4(+), odds ration [OR] = 1.79, 95% confidence interval [CI] 1.20-2.67; ACE D/D, OR = 1.42, 95% CI 1.05-1.92). The combined APOE epsilon4(+) and ACE D/D genetic status was associated with higher MPI grade (OR = 2.85, 95% CI 1.75-4.65), without interaction. No significant associations between APOE and ACE polymorphisms and 2-year mortality were found. APOE and ACE genes might predispose individuals to health and functional status deterioration in old age, and their effect is additive.

Cardiovascular and biochemical risk factors for incident dementia in the Hypertension in the Very Elderly Trial

OBJECTIVES

Several cardiovascular and biochemical factors including hypertension have been associated with cognitive decline and dementia, although both epidemiological and intervention evidence is mixed with the majority of studies examining those in midlife or younger elderly and the recent Hypertension in the Very Elderly Trial showing no significant association between blood pressure lowering and incident dementia. It has also been suggested that risk factors may differ in the very elderly. The aim of these analyses was to examine the impact of baseline cardiovascular and biochemical factors upon incident dementia and cognitive decline in a very elderly hypertensive group.

METHODS

Participants of the Hypertension in the Very Elderly Trial were aged at least 80 years and hypertensive. Cognitive function was assessed at baseline and annually with diagnostic information collected for dementia and relationships between baseline total and high-density lipoprotein cholesterol, creatinine, glucose, haemoglobin, heart failure, atrial fibrillation, diabetes, previous stroke and later dementia/cognitive decline were examined.

RESULTS

There were 3336 participants with longitudinal cognitive function data. In multivariate analyses higher creatinine was associated with a lower risk of incident dementia and cognitive decline. Higher total and lower high-density lipoprotein cholesterol were associated with lower risk of cognitive decline. Other variables were not significant.

CONCLUSIONS

In very elderly hypertensive patients heart failure, diabetes, atrial fibrillation, prior stroke, glucose and haemoglobin levels did not demonstrate a relationship with cognitive decline or dementia. Higher creatinine (excluding moderate renal impairment) was associated with a lower risk of dementia and cognitive decline. The findings for total and high-density lipoprotein cholesterol add to the varied literature in this area and together these findings may add weight to the suggestion that risk factor profiles differ in the very elderly.

Metabonomic characterization of aging and investigation on the anti-aging effects of total flavones of Epimedium

A liquid chromatography coupled with mass spectrometry (LC/MS) based metabonomics approach was applied to characterize the aging of rats, and the anti-aging effect of total flavones of Epimedium (TFE), a traditional Chinese medicine, has also been investigated. Serum samples collected from 4, 10, 18 and 24 month-old rats and TFE-administered rats have been profiled by LC/MS. Thirty age-related endogenous metabolites were discovered by partial least squares (PLS) and Hotelling's T(2) control chart, among which 25 metabolites were structurally identified by MS(n) analysis and ten of them were further confirmed via authentic chemicals. All important age-related metabolites, such as unsaturated fatty acids, saturated fatty acids, nucleotides, carnosine, ergothioneine and amino acids, displayed age-related changes, and most of them were reset to a younger level after TFE administration. This study indicated that aging could be characterized by changes of lipid metabolisms and accumulation of free radicals. The anti-aging effects of TFE might due to the intervention on lipid metabolism and its property of anti-oxidation.

Lack of genetic association between the angiotensin-converting enzyme gene insertion/deletion polymorphism and longevity in a Han Chinese population

Introduction. The insertion/deletion polymorphism of the angiotensin-converting enzyme (ACE) gene has been reported to associate with human longevity. However, little information is available in a Han Chinese longevity population.Therefore, we investigated the association of the ACE gene insertion/ deletion polymorphism with longevity in a Han Chinese population.

Materials and methods. We compared the distribution of ACE insertion/deletion genotype and allele frequencies in two groups: a longevity group (399 subjects) aged over 90 years and a control group (302 subjects) aged less than 60 years.

Results. No difference in genotype and allele frequencies of the ACE gene insertion/deletion polymorphism was observed between the longevity group and the control group.When adjusting for gender, the difference between the longevity group and the control group was also not significant regarding the frequencies of the genotypes (male, p=0.994 and female, p=0.797) as well as allele frequencies (male, p=0.969 and female, p=0.884).

Conclusions. No association of the ACE gene insertion/deletion polymorphism with longevity was observed in our Han Chinese population.