| ObjectiveHypertension is one of the most harmful common complex diseases, which have become a major public health burden worldwide. Blood pressure is a quantitative phenotype and has a continuous distribution. Multiple genetic and environmental factors determine one's blood pressure level, and essential hypertension is merely the upper end of the distribution.30-60% of the observed variation in blood pressure is attributable to genetic factors. Available evidence suggests that hypertension is results of a variety of genetic and environmental factors, genes-genes interactions, genes-environments interactions, with characteristics of genetic heterogeneity, delay dominance and ethnic differences. Mutations result in eight monogenic forms of hypertension has been identified and cloned, and most mutations directly affect renal Na+homoeostasis. Increased renal salt absorption is accompanied by increased water reabsorption, resulting in an augmented intravascular volume. Now, the relationship between high salt intake and BP increase has been convincingly established by epidemiological, observational, interventional, animal, and genetic studies. It was verified in animals that salt sensitivity is essentially related to the kidney and is regulated by genetic factors.The rural areas of Fuxin County, located in the north-west of Liaoning province, are high hypertension morbidity areas. The salt intake is more than 15g/d. The population is less mobility, and residence there seldom married with other population outside, therefore, the genetics background is relative simple. The selection of rural areas was based on homogeneity of the study population regarding their ethnicity and environmental exposures, including lifestyle and nutritional factors and habitual dietary intake of high salt.GPX3 gene code production is Glutathione peroxidase, a kind of selenocysteine-containing protein, which catalyzes the reduction of hydrogen peroxide, organic hydroperoxide, and lipid peroxides by reduced glutathione and functions in the protection of cells against oxidative damage. The association between decreased GPx-3 activity, arterial thrombosis, and the clinical manifestations of ischemic stroke and coronary artery disease indicates that the normal function of this enzyme is important for vascular homeostasis. Through a combination of creating novel congenic strains with higher resolution introgressed segments, targeted transcript sequencing and microarray gene expression profiling, increased SPON1 mRNA and protein expression is consistently observed in animals from which BP1 genomic region is derived from the SHR rather than WKY strain. Therefore, sponl have been identified as a novel strong candidate gene underlying a major blood pressure QTL on rat chromosome 1.The aim of the present study is to investigate the association GPX3 and spon1 gene with hypertension in Rural Han Chinese in Fuxin, Liaoning.Materials and Methods1. At Fuxin rural areas, Han people who lived there from ancestor was selected as participation.500 unrelated hypertension individuals were recruited, which had to meet the following criteria:(1)Age greater than 18 years;(2)Self-identified as having four Han Chinese grander parents;(3)Meet diagnostic criteria for hypertension;(4)No clinical or biochemical signs of secondary hypertension.500 unrelated control individuals were also recruited, which had to meet following criteria:(1)Age greater than 40 years; (2)Self-identified as having four Han Chinese grander parents;(3)Resting-sitting SBP<140mmHg and DBP<90mmHg. Both hypertension and control individuals were measured height and weight, and then BMI was calculated. FPG,TG,HDL-C,TC and LDL-C were determined with routine clinical laboratory test. Genomic DNA was extracted from whole blood by the standard procedures. The DNA quality and quantity were then determined using a NanoDrop(?) spectrophotometer. DNA samples had a 260/280 ratio between 1.65 and 2.1, a 260/230 ratio between 1.0 and 2.5 and concentration≥10ng/ul were accepted for pooling.100 ng of each individual's DNA was assigned to pool individually, yieLDLng a total of 10 independent DNA pools, including 5 hypertensives and 5 controls respectively. After the pools were generated, pyrosequencing was applied to allelotype.5 SNPs for GPX3 were selected, which are tagged common variants with MAF>0.1, r2≥0.9 in the HapMap CHB reference panel(rs8177412, rs3805435, rs3828599, rs8177435, rs2070593). The Fisher's exact test was used to test the association between the SNPs of GPX3 gene and hypertension. Bonferroni correction was adopted for multiple testing, and a pc value<0.05 was regarded as statistically significant.2. At Fuxin rural areas, Han people who lived there from ancestor was selected as participation.400 unrelated hypertension individuals were recruited, which had to meet the following criteria:(1)Age greater than 18 years;(2)Self-identified as having four Han Chinese grander parents;(3)Meet diagnostic criteria for hypertension;(4)No clinical or biochemical signs of secondary hypertension. (5)Including only nondiabetise, nonobesity, nondyslipidemia.403 unrelated control individuals were also recruited, which had to meet following criteria:(1)Age greater than 50 years; (2)Self-identified as having four Han Chinese grander parents;(3)Resting-sitting SBP<140mmHg and DBP <90mmHg. (4)No hypertension family history; (5) including only nondiabetise, nonobesity, nondyslipidemia. Both hypertension and control individuals were measured height and weight, and then BMI was calculated. FPG,TG,HDL-C,TC和LDL-C were determined with routine clinical laboratory test. Genomic DNA was extracted from whole blood by the standard procedures. The DNA quality and quantity were then determined using a NanoDrop(?) spectrophotometer. DNA samples had a 260/280 ratio between 1.65 and 2.1, a 260/230 ratio between 1.0 and 2.5 and concentration≥10ng/ul were accepted for pooling. 100ng of each individual's DNA was assigned to pool individually, yieLDLng 2 independent DNA pools, including 1 hypertensive and 1 control respectively. After the pools were generated, each of the 2 DNA pools was allelotyped using the the Affymetrix GeneChip(?) Human Mapping 500K Array set in accordance with the standard protocol for individual DNA samples.Results1. BMI, TC and LDL-C in hypertensives were significantly higher than those in controls. In nondiabetise, nonobesity, nondyslipidemia case-control study population, under normal range, BMI and LDL-C in hypertensives were significantly higher than those in controls.2. Before Bonferroni correction, C allele frequency for rs8177417 was significantly higher in hypertensives (23.4) than those in controls (19.3) (p=0.014); T allele frequency for rs8177417 was significantly lower in hypertensives (35.6) than those in controls (40.8) (p=0.014). However, when a Bonferroni correction for multiple testing was applied, only the polymorphisms rs3828599 of GPX3 gene was associated with hypertension (p=0.045, OR:0.833,95% CI:0.695-0.998).3. Genome wide association analysis showed p value of both rs11023059 and rs4757244 of sponl were lower than 10-5. So sponl was selected as candidate gene to analyze its association with essential hypertension.The sponl gene along with the adjacent 5000 base-pairs of 5'-upstream and 3'-downstream segments contained 90 SNPs on Affymetrix GeneChip(?) Human Mapping 500K Array.74 SNPs were selected with MAF≥0.1 in the HapMap CHB reference panel.12 SNPs with a DSsnp value< 0.04 and estimated MAF<10% were excluded from analysis. As a result,62 SNPs were enrolled. Among 62 SNPs, rs11238 located 3'-UTR, and rs4756787 located 3'-downstream, and the rest located intron. Except rs11023059 and rs4757244, p value of other four SNPs lower than 10-4(rs2303974,rs10832215,rs11023104,rs1406356). The allele frequency of rsl 1238 and rs4756787 had no significant difference. Conclusions1. The polymorphism of rs3828599 of GPX3 gene might be associated with hypertension in Rural Han Chinese in Fuxin, Liaoning.2. Through combining SNP microarray and DNA-pooling, in phenotype specific population (including only nondiabetise, nonobesity, nondyslipidemia), located hypertension casual gene on sponl intron 3,6 and 7 in Rural Han Chinese in Fuxin, Liaoning. |
PDF Full Text Request