Association of ATP1B1 single-nucleotide polymorphisms with blood pressure and hypertension in a Chinese population

Mineral Element Deposition and Gene Expression across Different Tissues of Cherry Valley Ducks

This study was conducted to investigate the deposition of several mineral elements and the mRNA levels of mineral-related genes across different tissues of cherry valley ducks. The contents of magnesium (Mg), potassium (K), zinc (Zn), and selenium (Se) in ducks' breast muscle, thigh muscle, liver, skin, and tibia at the age of 0, 21, 35, 49, and 63 days, respectively, were measured using an atomic fluorescence spectrophotometer, while the mRNA levels of mineral-related genes were detected by qRT-PCR. The results revealed that the dynamics of Mg and K were generally similar in each tissue, with a significant positive correlation (p < 0.05). In the breast muscle, thigh muscle, and liver, the contents of almost all mineral elements reached their peak values (p < 0.05) at the age of 49 to 63 days. Interestingly, the expression of most mineral-related genes was the highest at birth (p < 0.05). In addition, there was a significant negative correlation between the expression of ATP1A1 and the deposition of K (r = -0.957, p < 0.05), and a similar result was found for the expression of ATP8 and the deposition of Zn (r = -0.905, p < 0.05). Taken together, Mg and K could be used as joint indicators for the precise breeding of the high-quality strain of cherry valley ducks, while the age of 49 to 63 days could be used as the reference for the best marketing age. In addition, ATP1A1 and ATP8 could be used as the key genes to detect K and Zn, respectively. Hence, the findings of this study can be used to improve the production and breeding efficiency of high-quality meat ducks.

KLHL3 single-nucleotide polymorphism is associated with essential hypertension in Chinese Han population

Hypertension, including secondary and essential hypertension (EH) variants, is a multifactorial disease, affecting more than one billion people worldwide. Secondary hypertension results from mutations in the putative gene KLHL3 (Kelch-like protein 3); however, it has not been reported whether the KLHL3 gene polymorphisms are associated with EH. Here, we investigated the association between KLHL3 (rs2301708 and rs7444370) polymorphisms and EH in the Chinese Han population.This case-control study included 522 subjects-260 patients with EH and 262 normotensive controls matched for age, gender, body mass index (BMI), hemoglobin A1c (HbA1c), total cholesterol (TC), triglyceride (TG), and levels of Na, K, and Cl. The distribution of functional rs2301708 and rs7444370 polymorphisms within the KLHL3 gene was assessed through polymerase chain reaction (PCR) and restriction-fragment length polymorphism (RFLP).There was no significant difference in allelic and genotypic frequencies of KLHL3 rs2301708 between the EH and normotensive groups; however, the rs7444370 T allele and CT genotype in females was significantly associated with a protective effect against EH (P = .001, P = .002; P = .019, P = .052), and the haplotype CT of rs2301708 and rs7444370 among females in the EH group was less than in the normotensive group (P = .000; P = .007).The KLHL3 rs7444370 variant could be a protective factor in the pathogenesis of females' EH.

Association between Cullin-3 Single-Nucleotide Polymorphism rs17479770 and Essential Hypertension in the Male Chinese Han Population

Background

Hypertension, including essential and secondary hypertension, is a multifactorial disease, affecting more than one billion people worldwide. Secondary hypertension can result from mutations of cullin-3 (CUL3); however, whether polymorphisms of CUL3 are associated with essential hypertension (EH) has not been reported. Here, we investigated the association between CUL3 SNPs rs17479770 and rs3738952 and EH in the Chinese Han population.

Methods

This case-control study investigated 520 representatives, including 259 patients with EH and 261 normotensive controls matched for age, gender, BMI, TG, TC, and HbA1c for the distribution of functional rs17479770 and rs3738952 within the CUL3 gene by using PCR and RFLP.

Results

Our results showed that there was no significant difference in allele and genotype distribution of rs3738952 and haplotype distribution of rs17479770 and rs3738952 between the EH group and normotensive group, whereas the rs17479770 TT genotype in male and the full data set were significantly associated with the decreased risk of EH (P = 0.050, P = 0.042), and rs17479770 allele T in male was shown to have the correlation tendency of the decreased risk of EH (P = 0.064).

Conclusion

Our data suggest that the CUL3 rs17479770 variant could be a protective factor in the pathogenesis of EH.

Na+/K+-ATPase β1-subunit is recruited in Na-K-2Cl co-transporter isoform 2 multiprotein complexes in rat kidneys: possible role in blood pressure regulation

OBJECTIVE

The progression from prehypertensive to hypertensive state in spontaneous hypertensive rats (SHRs) is accompanied by a significant increase in membrane expression of Na-K-2Cl co-transporter isoform 2 (NKCC2), suggesting that the altered NKCC2 trafficking and activity are directly related with the development of hypertension in this strain. The aim of this work is to gain insights on the molecular mechanism that underlies this phenomenon.

METHODS

We performed a comparative analysis of NKCC2 multiprotein complexes (MPCs) in the kidney of SHRs versus Wistar Kyoto rats by Blue Native difference gel electrophoresis combined with mass spectrometry.

RESULTS

We found that the recruitment of the β-subunit isoform 1 of the Na(+)-K(+)-ATPase (β1NK) in NKCC2 MPCs was significantly increased in the kidneys of SHR compared with Wistar Kyoto rat control strain. Co-immunoprecipitation experiments showed that β1NK actually interacts with NKCC2 in the native tissue. The analysis of the physiological role of β1NK-NKCC2 interaction in human embryonic kidney cells showed that β1NK increased the steady-state membrane expression and activity of NKCC2 enhancing NKCC2 trafficking toward the plasma membrane.

CONCLUSION

We identify a new NKCC2-interacting partner involved in the modulation of NKCC2 intracellular trafficking and possibly involved in the regulation of blood pressure.

Recent Advances in the Genetics of Hypertension

Hypertension is a silent killer worldwide, caused by both genetic and environmental factors. Until now, genetic and genomic association studies of hypertension are reporting different degree of association on hypertension. Hence, it is essential to gather all the available information on the reported genetic loci and to determine if any biomarker(s) is/are significantly associated with hypertension. Current review concluded the potential biomarkers for hypertension, with regards to electrolyte and fluid transports, as well as sodium/potassium ions homeostasis, which are supported by the results of case-controls and meta-analyses.

Pharmacogenetics of cardiac inotropy

The ability to stimulate cardiac contractility is known as positive inotropy. Endogenous hormones, such as adrenaline and several natural or synthetic compounds possess this biological property, which is invaluable in the modern cardiovascular therapy setting, especially in acute heart failure or in cardiogenic shock. A number of proteins inside the cardiac myocyte participate in the molecular pathways that translate the initial stimulus, that is, the hormone or drug, into the effect of increased contractility (positive inotropy). Genetic variations (polymorphisms) in several genes encoding these proteins have been identified and characterized in humans with potentially significant consequences on cardiac inotropic function. The present review discusses these polymorphisms and their effects on cardiac inotropy, along with the individual pharmacogenomics of the most important positive inotropic agents in clinical use today. Important areas for future investigations in the field are also highlighted.

A polymorphic 3'UTR element in ATP1B1 regulates alternative polyadenylation and is associated with blood pressure

Although variants in many genes have previously been shown to be associated with blood pressure (BP) levels, the molecular mechanism underlying these associations are mostly unknown. We identified a multi-allelic T-rich sequence (TRS) in the 3’UTR of ATP1B1 that varies in length and sequence composition (T_22-27 and T₁₂GT ₃GT₆). The 3’UTR of ATP1B1 contains 2 functional polyadenylation signals and the TRS is downstream of the proximal polyadenylation site (A2). Therefore, we hypothesized that alleles of this TRS might influence ATP1B1 expression by regulating alternative polyadenylation. In vitro, the T₁₂GT ₃GT₆ allele increases polyadenylation at the A2 polyadenylation site as compared to the T₂₃ allele. Consistent with our hypothesis, the relative abundance of the A2-polyadenylated ATP1B1 mRNA was higher in human kidneys with at least one copy of the T₁₂GT ₃GT₆ allele than in those lacking this allele. The T₁₂GT ₃GT₆ allele is also associated with higher systolic BP (beta = 3.3 mmHg, p = 0.014) and diastolic BP (beta = 2.4 mmHg, p = 0.003) in a European-American population. Therefore, we have identified a novel multi-allelic TRS in the 3’UTR of ATP1B1 that is associated with higher BP and may mediate its effect by regulating the polyadenylation of the ATP1B1 mRNA.

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Association of ATP1B1, RGS5 and SELE polymorphisms with hypertension and blood pressure in African-Americans

OBJECTIVE

Although an increasing number of hypertension-associated genetic variants is being reported, replication of these findings in independent studies has been challenging. Several genes in a human chromosome 1q linkage region have been reported to be associated with hypertension. We examined polymorphisms in three of these genes (ATP1B1, RGS5 and SELE) in relation to hypertension and blood pressure in a cohort of African-Americans.

METHODS

We genotyped 87 single nucleotide polymorphisms (SNPs) from the ATP1B1, RGS5 and SELE genes in a well characterized cohort of 968 African-Americans and performed a case-control study to identify susceptibility alleles for hypertension and blood pressure regulation. Single SNP and haplotype association testing was done under an additive genetic model with adjustment for age, sex, BMI and ancestry-by-genotype (principal components).

RESULTS

A total of 12 SNPs showed nominal association with hypertension and/or blood pressure. The strongest signal for hypertension was for rs2815272 in the RGS5 gene (P = 9.3 × 10). For SBP, rs3917420 in the SELE gene (P = 9.0 × 10) and rs4657251 in the RGS5 gene (P = 9.7 × 10) were the top hits. Effect size for each of these variants was approximately 2-3 mmHg. A five-SNP haplotype in the SELE gene also showed significant association with SBP after correction for multiple testing (P < 0.01).

CONCLUSION

These findings provide additional support for the genetic role of ATP1B1, RGS5 and SELE in hypertension and blood pressure regulation.