How ineffective hypertension control in subjects treated with angiotensin-converting enzyme inhibitors is related to polymorphisms in the renin-angiotensin-aldosterone system

Mechanism of Mongolian mind-body interactive therapy in regulating essential hypertension through HTR2B: A metabolome- and transcriptome-based study

Essential hypertension is a psychosomatic disease associated with emotions and behaviors. Although Mongolian mind-body interactive therapy can help patients with essential hypertension reduce their systolic blood pressure (SBP), the mechanism is unclear. We assigned patients who underwent Mongolian mind-body interactive therapy to groups that were treated with (DT) or without (NDT) antihypertensive drugs (Clinical registration no: ChiCTR2000034918). We screened differentially expressed genes (DEGs) using targeted metabolic and transcriptomic analyses of blood samples before and after intervention. Sequenced data were analyzed using quantitative polymerase chain reaction (qPCR) and validated using enzyme-linked immunosorbent assays (ELISAs). Small interfering (Si)-RNA interference on key DEGs in human umbilical vein endothelial cells (HUVECs) was experimentally verified. Omics analysis identified 187 DEGS, including human 5-hydroxytryptamine (5-HT) receptor 2B (5-HTR2B), human endothelin receptor type B (EDNRB), and the metabolite N-acetylserotonin. The qPCR and transcriptome sequencing results were consistent. Post-intervention ELISA assays revealed significantly elevated 5-HT in the NDT group after intervention (P < 0.05). Interactions between 5-HTR2B and N-acetylserotonin differed between the groups. The cellular findings showed significantly reduced G protein-coupled receptor 82 (GPR82) and phospholipid phosphatase-related protein type 4 (PLPPR4), and significantly increased S100A2 protein expression in the Si-HTR2B group, compared with the controls (P < 0.05). The biochemical results uncovered significantly decreased nitric oxide (NO) and significantly increased malondialdehyde and NO synthetase concentrations compared with the models (P < 0.05). Mongolian mind-body interactive therapy might affect SBP in patients with essential hypertension by combining 5-HT with 5-HTR2B to mediate NO relaxation.

A polymorphism of the renin gene rs6682082 is associated with essential hypertension risk and blood pressure levels in Korean women

PURPOSE

The aim of the present study was to investigate associations between the renin gene (REN) and the risk of essential hypertension and blood pressure (BP) levels in Koreans.

MATERIALS AND METHODS

To outline the functional role of a single nucleotide polymorphism in the transcription of the REN gene, we conducted a case-control study of 1975 individuals: 646 hypertension (HT) patients and 1329 ethnically and age-matched normotensive subjects.

RESULTS

Logistic regression analysis indicated that the genotypes AA/AG were strongly associated with risk of HT (odds ratio, 1.493; 95% confidence interval, 1.069-2.086, p=0.018) in female subjects. The genotypes AA/AG also showed significant association with higher blood pressure levels, both systolic and diastolic, in postmenopausal HT women (p=0.003 and p=0.017, respectively). Analysis of the promoter containing rs6682082 revealed a 2.4±0.01-fold higher activity in the A variant promoter than the G variant promoter, suggesting that rs6682082 is itself a functional variant.

CONCLUSION

We suggest that the A allele of rs6682082 is a positive genetic marker for predisposition to essential hypertension and high BP in Korean women and may be mediated through the transcriptional activation of REN.

Influence of the AGTR1 A1166C genotype on the progression of arterial stiffness: A 16-year longitudinal study

BACKGROUND

We examined the influence of the AGTR1 A1166C genotype on the 16-year evolution of pulse wave velocity (PWV) in a middle-aged population. In a cross-sectional study, we reported that the presence of the AGTR1 1166C allele was associated with higher aortic stiffness compared with the AGTR1 1166AA genotype.

METHODS

The study was conducted in 259 subjects who underwent 3 health check-ups over 16 years at the Centre IPC-Paris: an initial visit in 1992-1993, an intermediate visit in 1998-1999, and a final visit in 2007-2008. Aortic stiffness was assessed during the 3 visits by measuring carotid-femoral PWV. AGTR1 A1166C polymorphism was assayed by allele-specific oligonucleotide hybridization.

RESULTS

AGTR1 1166C allele carriers (AC + CC genotypes) had a 35% more pronounced increase in PWV over this 16-year period when compared with the AGTR1 1166AA subjects (3.01 ± 0.32 vs. 1.92 ± 0.23 m/s; P < 0.001). This increase remained significant after adjustment for age, sex, initial PWV values, and changes in blood pressure (+37%; P < 0.05). The genotype-related differences in PWV were only observed at the last visit (i.e., later in life, after the age of 55 years). The effects of this genotype on PWV were not related to the presence of antihypertensive treatment.

CONCLUSIONS

This is the first long-term longitudinal study indicating that AT1 1166C carriers are at increased risk of pronounced arterial stiffening during aging especially after the age of 55.

Interactions of renin–angiotensin system gene polymorphisms and antihypertensive effect of benazepril in Chinese population

Aim: Angiotensin-converting enzyme inhibitors are widely used antihypertensive drugs with individual response variation. We studied whether interactions of AGT, AGTR1 and ACE2 gene polymorphisms affect this response. Materials & methods: Our study is based on a 3-year field trial with 1831 hypertensive patients prescribed benazepril. Generalized multifactor dimensionality reduction was used to explore interaction models and logistic regressions were used to confirm them. Results: A two-locus model involving the AGT and ACE2 genes was found in males, the sensitive genotypes showed an odds ratio (OR) of 1.9 (95% CI: 1.3–2.8) when compared with nonsensitive genotypes. Two AGT–AGTR1 models were found in females, with an OR of 3.5 (95% CI: 2.0–5.9) and 3.1 (95% CI: 1.8–5.3). Conclusion: Gender-specific gene–gene interactions of the AGT, AGTR1 and ACE2 genes were associated with individual variation of response to benazepril. Further studies are needed to confirm this finding.

Original submitted 1 November 2010; Revision submitted 10 January 2011