Genetic Research Of Four Aging-related Genes In Shenyang Healthy Population

BackgroundAging also known as senescence, usually refers to the normal conditions of biological maturity, increased with age, their function decline, stable capacity and stress within the environment reduced capacity, structure, composition degeneration gradually towards death and irreversible. In the late 20th century, the theory of molecular biology and cell biology technology utilize in Gerontology research, the researchers found that although there has a wide range of the theories of aging, but no more than genetic and environmental aspects. Mutation of the WRN gene located on chromosome 8p-12 induce Wemer progeria syndrome (adult progeria); the same aging of different individuals have different phenotypes and different life; family investigation, twin, and popular disease studies all shown that aging is a highly individualized process, closely related to genetic factors.Rate of aging varies in different Individuals, the differences between human individuals has also increased with age. Some people are very good of physical and cognitive function in 85 years, but some people may occur a wide range of cognitive impairment or physical dysfunction in 55 years, Chronological age (CA) can not serve as aging the process of accurate instructions. For basic and clinical research of aging purposes, researchers concerned with aging changes in the individual the purpose of screening individuals at high risk of aging and provide timely intervention. To solve the above problems, researchers proposed the "Biological Age (BA)" concept. Biological age relative to the timing age of the individual functional state of their peers based on the evaluation of the individual's functional status. Individual aging at different rates leading to timing differences in age and biological age, so the timing of any given age, individuals between the value of biological age may be different, and ultimately the individual can be expected with the aging process results in time and/or the magnitude of the difference was consistent.Decreased in senescent human body functions, and enhanced susceptibility to some diseases, some people will live longer seen as a successful aging phenotypes, from this point of view, some of the older disease-related genes and longevity-related genes can also be seen as aging-related genes. Many scholars believe that aging like hypertension, atherosclerosis, dementia, cancer and other disease, not the decision of a single gene, but is likely to be influenced by a large and complex aging-related genes in gene cluster. Study the aging process of gene expression profile, screening of new gene, isolated and cloned senescence-related genes, to understand its function, regulation, impact factor is the real way to find out the mechanism of aging. Biological function to genes as candidate genes for association studies of genetic susceptibility to the current aging of the main strategy. The results show that variations in the genome sequence, that gene polymorphism is to determine the susceptibility of the human body to age related diseases and resistance to aging and the clinical phenotype diversity of human response to drug treatment an important factor in differences.Polymorphism of DNA can be divided into three phases:Restriction Fragment Length Polymorphism, Microsatellite Polymorphisms and Single Nucleotide Polymorphisms (SNP). SNPs compared to the previous two generations its high density of genetic markers, genetic stability, representative, are distributed unevenly and its analysis automation.SNPs changes, especially in the coding region and the SNPs in the expression and regulation changes in the sequence, protein expression may lead to changes in the quality or quantity, thereby affecting protein structure or expression. Thus SNPs may help explain the phenotypic differences between individuals, groups and individual susceptibility to aging and longevity difference. Find the aging and diseases of aging-related SNP, is one of the important way to reveal the cause of human aging. Insulin/insulin like growth factor-1 (insulin/IGF-1) way to many kinds of protein interactions at the same time regulating the expression of a large number of genes, Sirt1, IL-6, P16, and Klotho genes or the involvement of four insulin/IGF-1 signaling pathway and the insulin/IGF-1 signaling pathway, or interactions which may affect the aging process. IL-6 is an inflammatory cytokine, which can affect the number of inflammatory and aging-related diseases, the development of which may ultimately affect the aging process; Sirt1 is a mammalian NAD+dependent deacetylase, in the cell cycle arrest and play a role in DNA repair, which can be reduced apoptosis, regulation of cell aging; p16 related to telomere shortening, cell senescence in markedly enhanced when the regular expression; Klotho can affect the intracellular signaling pathway to regulate fibroblast growth factor 23 signals, p53/p21, cAMP, protein kinase C (PKC) and the Wnt signaling pathway, repair, and regulation of endothelial dysfunction, production of nitric oxide, which may affect the aging process.In this study, case-control candidate gene approach to China, Shenyang Han population, according to biological age groups, using Snapshot method detected 10 SNPs in Sirtl, IL6, P16, and Klotho genes, and detect the genotypes and gene frequency of these genes the relationship between these SNPs and aging. The results obtained will help to further elucidate the molecular genetic mechanisms of aging, and can achieve the level of the genes on the aging individual evaluation, as well as the future treatment of pathological aging diagnostic lay an important experimental basis.Materials and methodsThis study used case-control study, selected from more than 1,507 people, choose 442 healthy people, the 70 indexes reflecting the brain functions, heart function, vascular function, lung function, kidney function and reaction conditions of the general indicators of daily using statistical methods construction the Biological age score (BAS) formula, the study according to biological age group, divided into 228 patients aged group and 213 young people. Bioinformatics approach to select 10 SNPs in four of candidate genes. Individual genotypes were detected using Snapshot. With the goodness of fit chi-square test verifies that each SNP genotype distribution in the sample population is consistent with HW equilibrium, using Genepop3.4 software testing H-W (Hardy-Weinberg) equilibrium. Using SPSS statistical software to analyze each SNP allele and genotype in the young group and the distribution between the aging group is significantly different to speculate SNPs, the relationship with aging. Using SPSS statistical software-related data X2 test, measurement data with mean±sd, p<0.05 as significant difference. Shesis software analysis using linkage disequilibrium between SNPs level of the same gene interaction between the different sites.Results1. Selected seven biomarkers TMT, CCR, MVES, IMTmin, Dmax, MMEF75/25, PP, and biological age successfully constructed integral formula, BAS=-0.169 (CCR)-0.179(MVES)+0.184 (IMTmin)+0.155 (Dmax)-0.158 (MMEF75/25)+0.226 (CA) +0.148 (PP)+0.159 (TMT).2. Aging and young groups for each SNP genotype H-W equilibrium test are keep balance, we chose the study sample can represent the whole people.3. The frequency distribution of IL-6 gene polymorphism in healthy young and aging group compared:rs2066992 locus genotypes between the two groups no significant difference, X2=0.05, P=0.82; alleles between the two groups no significant difference, X2=0.09, OR=0.95,95%CI=0.69-1.30, P=0.76; rs1524107 locus genotypes between the two groups no significant difference, X2=0.32, P=0.57; allele frequencies between the two groups no significant difference, X2=0.20, P=0.66, OR=0.932,95% CI:0.685-1.268.4. The frequency distribution of P16 gene polymorphism in aging and young groups compared:rs2811708 locus genotypes between the two groups no significant difference, X2=0.28, P=0.59; allele frequencies between the two groups There was no significant difference, X2=0.24, P=0.62, OR=0.94,95%CI:0.718-1.219; rs3731245 locus genotypes between the two groups no significant difference, X2=0.34, P=0.79; allele frequency between the two groups have no significant difference, X2=0.15, OR=0.94,95%CI= 0.70-1.27, P=0.70.5. The frequency distribution of Klotho gene polymorphism in aging and young groups compared:rs571118 site CC genotype frequency higher aging group, while the CT type and TT genotype frequency lower than the control group, there was significant difference in X2=7.28, P=0.006; T allele and C allele has significant difference between the two groups, X2=6.78, P=0.01, OR=1.42,95%CI:1.09-1.86. rs1207568 CC-type locus aging group, CT-based and TT genotype frequency in the aging and young groups, the difference was significant, X2=5.18, P=0.02; there are significant differences allele frequencies between the two groups, X2=5.18, OR=1.308,95%CI=0.78-1.38, P=0.02. rs2149860 genotypes between the two groups have no significant difference, X2=0.30, P=0.58; allele frequencies between the two groups no significant difference, X2=0.31, OR=1.077,95%CI=0.827-1.403, P=0.58. Klotho gene rs648202 genotypes between the two groups have no significant difference, X=0.11, P=0.74; allele frequencies between the two groups have no significant difference, X=0.21, P=0.64, OR=0.93, 95%CI:0.69-1.26.6. Sirt1 gene polymorphism in aging and young groups in the frequency distribution, Sirtl gene locus rs3758391 genotype between the two groups no significant difference, X2=0.13, P=0.71; allele frequencies in two there were no significant differences, X2=0.71, OR=1.14,95%CI=0.83-2.02, P=0.026. Sirtl gene rs4746720 genotype CC genotype frequency aging group compared with the control group showed significant:X2=3.85, P=0.04; C lower than the control group allele frequency The difference was statistically significant:X2=4.35, OR=1.328,95%CI= 1.02-1.73, P= 0.03.7. Linkage Disequilibrium analysisRs571118, rs2149860, rs 1207568, rs648202 in Klotho, the four sites D′<0.6, rs571118, rs2149860, rs1207568, rs648202 has no correlation with each other.The D′of rs2066992, rs1 524107 in IL-6=0.99, rs2066992 strong correlation with rs1524107. The D'of rs2811708, rs3731245 in P16=0.92, rs2811708 strong correlation with rs3731245.Rs3758391, rs4746720 of Sirtl gene D'=0.53. Rs3758391and rs4746720 has no relation.Conclusion1. Biological age score formula successfully constructed, devide group using biological age, more reasonable than the traditional timing age of the individual to reflect the aging process.2. Klotho gene rs571118 of the GG genotype and rs1207568 CC genotype may be sites of Shenyang Han population aging risk factors, mainly from the genetic susceptibility alleles G and C. Klotho gene rs2149860 and rs648202 no correlation with Shenyang Han population aging.3. IL-6 gene rs2066992, rs 1524107 polymorphism has no correlation with Shenyang Han population aging.4. P16 gene rs2811708, rs3731245 polymorphism as no correlation with Shenyang Han population aging.5. Sirtl gene rs4746720 CC genotype may impact as Shenyang Han population aging risk factors, mainly from the genetic susceptibility allele C, Sirtl gene rs3758391 polymorphism and Shenyang Han population aging no correlation.