Association between circulating levels of ACE2-Ang-(1-7)-MAS axis and ACE2 gene polymorphisms in hypertensive patients.
ABSTRACT: The angiotensin-converting enzyme 2-angiotensin-(1-7)-MAS axis (ACE2-Ang-[1-7]-MAS axis) plays an important role in the control of blood pressure. Some previous studies indicated that the genetic variants of ACE2 may have a potential to influence this axis. Therefore, the present study aimed at examining the association of ACE2 polymorphisms with circulating ACE2 and Ang-(1-7) levels in patients with essential hypertension.Hypertensive patients who met the inclusion criteria were enrolled in the present study. Three Tag single-nucleotide polymorphisms (rs2106809, rs4646155, and rs879922) in ACE2 gene were genotyped for all participants. Circulating ACE2 and Ang-(1-7) levels were detected by enzyme-linked immunosorbent assay.There were 96 (53.0%) females and 85 (47.0%) males participating in the present study. The circulating Ang-(1-7) levels were significantly greater in female patients carrying the rs2106809 CC or CT genotype compared with those carrying the TT genotype (1321.9 ± 837.4 or 1077.5 ± 804.4 pg/mL vs 751.9 ± 612.4 pg/mL, respectively; P = 0.029, analysis of variance), whereas the circulating Ang-(1-7) levels were comparable among genotypes in male patients. In addition, there was no significant difference in the circulating ACE2 levels among rs2106809 CC, CT, and TT genotype groups in both female and male patients. The circulating ACE2 and Ang-(1-7) levels were related to neither rs4646155 nor rs879922 in female or male patients.In conclusion, the rs2106809 polymorphism of the ACE2 gene may be a determinant of the circulating Ang-(1-7) level in female patients with hypertension, suggesting a genetic association between circulating Ang-(1-7) levels and ACE2 gene polymorphisms in patients with hypertension.
Project description:BACKGROUND:Cardiovascular benefits by reversing environmental risks factors for essential hypertension (EH) and dyslipidemia could be weaken by high genetic risk. We investigated possible associations between ACE2 polymorphisms and dyslipidemia in patients with EH. METHODS:Four hundred and two hypertensive patients were enrolled in an EH group and 233 normotensive individuals were enrolled as control group from the Xinjiang region of China. Fourteen ACE2 polymorphisms were genotyped by Matrix-assisted laser desorption ionization time-of-flight mass spectrometry. RESULTS:Participants carrying T allele (TT?+?CT) of rs2074192 (P?=?0.006), rs4646155 (P?=?0.030) and rs4646188 (P?<?0.001), C allele (CT?+?CT or CC?+?CG) of rs4240157 (P?=?0.012), rs4830542 (P?=?0.020) and rs879922 (P?<?0.001) and TT genotype of rs2106809 (P?=?0.012) were associated with EH. Meanwhile,ACE2 SNPs also exhibited association with dyslipidemia but exhibited obvious heterogeneity. rs1978124 (TT?+?CT, P?=?0.009), rs2106809 (TT, P?=?0.045), rs233575 (CC?+?CT, P?=?0.018), rs4646188 (CC, P?=?0.011) and rs879922 (CC?+?CG, P?=?0.003) were association with increased LDL-C (?1.8 mmol/L). rs2106809 (CC?+?CT, P?<?0.001), rs2285666(TT?+?CT, P?=?0.017), rs4646142(CC?+?CG, P?=?0.044), rs4646155(TT?+?CT, P?<?0.001) and rs4646188(TT?+?CT, P?=?0.033) were association with decreased HDL-C (<?1.0 mmol/L). rs2074192 (TT?+?CT, P?=?0.012), rs4240157 (CC?+?CT, P?=?0.027), rs4646156 (AA+AT, P?=?0.007), rs4646188 (TT?+?CT, P?=?0.005), rs4830542 (CC?+?CT, P?=?0.047) and rs879922 (CC?+?CG, P?=?0.001) were association with increased TC (?5.2 mmol/L). rs2106809 (P?=?0.034) and rs4646188 (P?=?0.013) were associated with hypertriglyceridemia. Further, ischemic stroke was more prevalent with rs4240157 (CC?+?CT, P?=?0.043), rs4646188 (CC?+?CT, P?=?0.013) and rs4830542 (CC?+?CT, P?=?0.037). In addition, rs2048683 and rs6632677 were not association with EH, dyslipidemia and ischemic stroke. CONCLUSION:The ACE2 rs4646188 variant may be a potential and optimal genetic susceptibility marker for EH, dyslipidemia and its related ischemic stroke.
Project description:As a counter-regulatory arm of the renin angiotensin system (RAS), the angiotensin-converting enzyme 2-angiotensin-(1-7)-MAS axis (ACE2-Ang-(1-7)-MAS axis) plays a protective role in cardiovascular diseases. However, the link between circulating levels of ACE2-Ang-(1-7)-Mas axis and coronary atherosclerosis in humans is not determined. The object of present study was to investigate the association of circulating levels of ACE2, Ang-(1-7) and Ang-(1-9) with coronary heart disease (CHD) defined by coronary angiography (CAG). 275 patients who were referred to CAG for the evaluation of suspected CHD were enrolled and divided into two groups: CHD group (diameter narrowing???50%, n?=?218) and non-CHD group (diameter narrowing?<?50%, n?=?57). Circulating ACE2, Ang-(1-7) and Ang-(1-9) levels were detected by enzyme-linked immunosorbent assay (ELISA). In females, circulating ACE2 levels were higher in the CHD group than in the non-CHD group (5617.16?±?5206.67 vs. 3124.06?±?3005.36 pg/ml, P?=?0.009), and subgroup analysis showed the significant differences in ACE2 levels between the two groups only exist in patients with multi-vessel lesions (P?=?0.009). In multivariate logistic regression, compared with the people in the lowest ACE2 quartile, those in the highest quartile had an OR of 4.33 (95% CI 1.20-15.61) for the CHD (P for trend?=?0.025), the OR was 5.94 (95% CI 1.08-32.51) for the third ACE2 quartile and 9.58 (95% CI 1.61-56.95) for the highest ACE2 quartile after adjusting for potential confounders (P for trend?=?0.022). However, circulating Ang-(1-7) and Ang-(1-9) levels had no significant differences between the two groups. In males, there were no significant differences in the levels of ACE2-Ang-(1-7)-MAS axis between two groups. Together, circulating ACE2 levels, but not Ang-(1-7) and Ang-(1-9) levels, significantly increased in female CHD group when compared with non-CHD group, increased ACE2 was independently associated with CHD in female and in patients with multi-vessel lesions even after adjusting for the confounding factors, indicating that ACE2 may participate as a compensatory mechanism in CHD.
Project description:BACKGROUND:The renin-angiotensin system (RAS) has significant influences on heart and renal disease progression. Angiotensin converting enzyme (ACE) and angiotensin converting enzyme II (ACE2) are major peptidases of RAS components and play counteracting functions through angiotensin II (Ang II)/ATIR and angiotensin-(1-7) (Ang-(1-7))/Mas axis, respectively. METHODS:There were 360 uremic patients on regular hemodialysis (HD) treatment (inclusive of 119 HD patients with cardiovascular diseases (CVD) and 241 HD patients without CVD and 50 healthy subjects were enrolled in this study. Plasma ACE, ACE2, Ang II and Ang-(1-7) levels of the HD patients were determined. RESULTS:We compared pre-HD levels of plasma ACE, ACE2, Ang II and Ang-(1-7) in the HD patients with and without CVD to those of the controls. The HD patients, particularly those with CVD, showed a significant increase in the levels of ACE and Ang II, whereas ACE2 and Ang-(1-7) levels were lower than those in the healthy controls. Therefore, imbalanced ACE/ACE2 was observed in the HD patients with CVD. In the course of a single HD session, the plasma ACE, ACE/ACE2 and Ang II levels in the HD patients with CVD were increased from pre-HD to post-HD. On the contrary, ACE2 levels were decreased after the HD session. These changes were not detected in the HD patients without CVD. CONCLUSIONS:Pathogenically imbalanced circulating ACE/ACE2 was detected in the HD patients, particularly those with CVD. HD session could increase ACE/Ang II/AT1R axis and decrease ACE2/Ang-(1-7)/Mas axis activity in the circulation of HD patients with CVD.
Project description:We tested the hypothesis that activation of the protective arm of the renin angiotensin system, the angiotensin-converting enzyme 2 (ACE2)/angiotensin-(1-7) [Ang-(1-7)]/Mas receptor axis, corrects the vasoreparative dysfunction typically seen in the CD34(+) cells isolated from diabetic individuals. Peripheral blood CD34(+) cells from patients with diabetes were compared with those of nondiabetic controls. Ang-(1-7) restored impaired migration and nitric oxide bioavailability/cGMP in response to stromal cell-derived factor and resulted in a decrease in NADPH oxidase activity. The survival and proliferation of CD34(+) cells from diabetic individuals were enhanced by Ang-(1-7) in a Mas/phosphatidylinositol 3-kinase (PI3K)/Akt-dependent manner. ACE2 expression was lower, and ACE2 activators xanthenone and diminazine aceturate were less effective in inducing the migration in cells from patients with diabetes compared with controls. Ang-(1-7) overexpression by lentiviral gene modification restored both the in vitro vasoreparative functions of diabetic cells and the in vivo homing efficiency to areas of ischemia. A cohort of patients who remained free of microvascular complications despite having a history of longstanding inadequate glycemic control had higher expression of ACE2/Mas mRNA than patients with diabetes with microvascular complications matched for age, sex, and glycemic control. Thus, ACE2/Ang-(1-7)\Mas pathway activation corrects existing diabetes-induced CD34(+) cell dysfunction and also confers protection from development of this dysfunction.
Project description:BACKGROUND:Type 2 diabetes mellitus (T2D), rapidly increasing to epidemic proportions, globally escalates cardiovascular disease risk. Although intensive interventions and comprehensive management of environmental risks factors for T2D are associated with reduced cardiovascular disease, such approaches are limited for individuals with high genetic T2D risk. In this study we investigated possible associations of ACE2 polymorphisms and cardiovascular risks in Uygur patients with T2D. METHODS:275 Uygur T2D patients and 272 non-diabetic Uygur individuals were enrolled as study participants. 14 ACE2 polymorphisms were genotyped by Matrix-assisted laser desorption ionization time-of-flight mass spectrometry. RESULTS:ACE2 SNP rs1978124, rs2048683, rs2074192, rs233575, rs4240157, rs4646156, rs4646188 and rs879922 were associated with T2D (all P < 0.05). The 8 diabetic risk related ACE2 SNPs were further associated with diabetic related cardiovascular complications or events but exhibited heterogeneity as fellows: firstly, almost all diabetic risk related ACE2 SNPs (all P < 0.05) were associated with increased SBP except rs1978124 and rs2074192, while rs2074192, rs4646188 and rs879922 were associated elevated DBP (all P < 0.05). Secondly, SNP rs4646188 was not correlated with any type of dyslipidemia (TRIG, HDL-C, LDL-C or CHOL), and the other 7 diabetic risk related loci were at least correlated with one type of dyslipidemia (all P < 0.05). In particular, rs879922 were simultaneously correlated with four type of dyslipidemia (all P < 0.05). Thirdly, ACE2 SNP rs2074192 and rs879922 were associated with carotid arteriosclerosis stenosis (CAS) ≥ 50% (both P < 0.05). Fourthly, ACE2 SNP rs2074192, rs4240157, rs4646188 and 879922 were associated with increased MAU (all P < 0.05). In addition, ACE2 SNP rs2048683, rs4240157, rs4646156, rs4646188 and rs879922 were linked to heavier LVMI (all P < 0.05), but only rs4240157, rs4646156 and rs4646188 were associated with lower LVEF (all P < 0.05). CONCLUSION:ACE2 SNP rs879922 may be a common genetic loci and optimal genetic susceptibility marker for T2D and T2D related cardiovascular risks in Uygurs.
Project description:Essential hypertension (EH) is a principal contributing factor in worldwide cardiovascular disease mortality. Although interventions that minimize environmental risk factors for EH are associated with reduced cardiovascular disease, such approaches are limited for individuals with high genetic EH risk. In this study, we investigated possible associations between ACE2 polymorphisms and hypertension-related target organ damages in south Xinjiang, China. Four hundred and two hypertensive patients were enrolled as study participants in an EH group, and 233 normotensive individuals were enrolled as control subjects. Participants were recruited from the south Xinjiang region. Fourteen ACE2 polymorphisms were genotyped by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Risk genotypes of rs2074192 (TT+CT, OR?=?1.72, 95% CI: 1.17-2.53), rs2106809 (TT, OR?=?1.71, 95% CI: 1.13-2.58), rs4240157 (CC+CT, OR?=?1.99, 95% CI: 1.17-3.41), rs4646155 (TT+CT, OR?=?1.94, 95% CI: 1.06-3.54), rs4646188 (TT+CT, OR?=?3.25, 95% CI: 1.95-5.41), rs4830542 (CC+CT, OR?=?1.88, 95% CI: 1.10-3.23), and rs879922 (CC+CG, OR?=?4.86, 95% CI: 2.74-8.64) were associated with EH. Hypertensive patients carrying the control genotype of rs2074192 (CC, OR?=?2.37, 95% CI: 1.28-4.39) were associated with CAS ?50%, while those carrying a high-EH-risk genotype of rs4240157 (OR?=?2.62, 95% CI: 1.24-5.54), rs4646155 (OR?=?2.44, 95% CI: 1.16-5.10), or rs4830542 (CC+CT, OR?=?2.20, 95% CI: 1.03-4.69) were associated with atrial fibrillation (AF), larger left atrial diameter, and higher levels of renin-angiotensin-aldosterone system (RAAS) activation (renin and angiotensin I/II). In conclusion, the ACE2 variant rs2074192 was associated with EH and EH with CAS ?50%, while 3 ACE2 variants (rs4240157, rs4646155, and rs4830542) were associated with EH- and hypertension-related AF and left atrial remodeling in south Xinjiang, China.
Project description:Angiotensin II (Ang II) has been shown to have both central and peripheral effects in mediating hypertension, for which the hypothalamic paraventricular nucleus (PVN) is an important brain cardio-regulatory centre. Angiotensin-converting enzyme 2 (ACE2) has been identified as a negative regulator of the pro-hypertensive actions of Ang II. Recent findings from our laboratory suggest that Ang II infusion decreases ACE2 expression in the PVN. In the present study, we hypothesized that ACE2 overexpression in the PVN will have beneficial effects in counteracting Ang II-induced hypertension.Male Sprague-Dawley rats were used in this study. Bilateral microinjection of an adenovirus encoding hACE2 (Ad-ACE2) into the PVN was used to overexpress ACE2 within this region. Mean arterial pressure measured by radiotelemetry was significantly increased after 14 days in Ang II-infused (200 ng/kg/min) rats vs. saline-infused controls (162.9 ± 3.6 vs. 102.3 ± 1.5 mmHg). Bilateral PVN microinjection of Ad-ACE2 attenuated this Ang II-induced hypertension (130.2 ± 5.7 vs. 162.9 ± 3.6 mmHg). ACE2 overexpression also significantly decreased AT(1)R and ACE expression and increased AT(2)R and Mas expression in the PVN. Additionally, ACE2 overexpression in the PVN attenuated the Ang II-induced increase in the expression of the pro-inflammatory cytokines tumour necrosis factor-?, interleukin (IL)-1? and IL-6 in the PVN.Our findings suggest that attenuation of pro-inflammatory cytokines in the PVN in combination with the shift of the renin-angiotensin system towards the anti-hypertensive axis (ACE2/Ang-(1-7)/Mas) may be responsible for the overall beneficial effects of ACE2 overexpression in the PVN on the Ang II-induced hypertensive response.
Project description:Despite evidence that hyperactivity of the vasodeleterious axis (ACE/angiotensin II (Ang II)/AT1 receptor) of the renin-angiotensin system (RAS) is associated with the pathogenesis of diabetic retinopathy (DR) use of the inhibitors of this axis has met with limited success in the control of this pathophysiology. We investigated the hypothesis that enhancing the local activity of the recently established protective axis of the RAS, ACE2/Ang-(1-7), using adeno-associated virus (AAV)-mediated gene delivery of ACE2 or Ang-(1-7) would confer protection against diabetes-induced retinopathy. Genes expressing ACE2 and Ang-(1-7) were cloned in AAV vector. The effects of ocular AAV-ACE2/Ang-(1-7) gene transfer on DR in diabetic eNOS(-/-) mice and Sprague-Dawley (SD) rats were examined. Diabetes was associated with approximately tenfold and greater than threefold increases in the ratios of ACE/ACE2 and AT1R/Mas mRNA levels in the retina respectively. Intraocular administration of AAV-ACE2/Ang-(1-7) resulted in significant reduction in diabetes-induced retinal vascular leakage, acellular capillaries, infiltrating inflammatory cells and oxidative damage in both diabetic mice and rats. Our results demonstrate that DR is associated with impaired balance of retinal RAS. Increased expression of ACE2/Ang-(1-7) overcomes this imbalance and confers protection against DR. Thus, strategies enhancing the protective ACE2/Ang-(1-7) axis of RAS in the eye could serve as a novel therapeutic target for DR.
Project description:Hyperactivity of the renin-angiotensin system (RAS) resulting in elevated Angiotensin II (Ang II) contributes to all stages of inflammatory responses including ocular inflammation. The discovery of angiotensin-converting enzyme 2 (ACE2) has established a protective axis of RAS involving ACE2/Ang-(1-7)/Mas that counteracts the proinflammatory and hypertrophic effects of the deleterious ACE/AngII/AT1R axis. Here we investigated the hypothesis that enhancing the systemic and local activity of the protective axis of the RAS by oral delivery of ACE2 and Ang-(1-7) bioencapsulated in plant cells would confer protection against ocular inflammation. Both ACE2 and Ang-(1-7), fused with the non-toxic cholera toxin subunit B (CTB) were expressed in plant chloroplasts. Increased levels of ACE2 and Ang-(1-7) were observed in circulation and retina after oral administration of CTB-ACE2 and Ang-(1-7) expressing plant cells. Oral feeding of mice with bioencapsulated ACE2/Ang-(1-7) significantly reduced endotoxin-induced uveitis (EIU) in mice. Treatment with bioencapsulated ACE2/Ang-(1-7) also dramatically decreased cellular infiltration, retinal vasculitis, damage and folding in experimental autoimmune uveoretinitis (EAU). Thus, enhancing the protective axis of RAS by oral delivery of ACE2/Ang-(1-7) bioencapsulated in plant cells provide an innovative, highly efficient and cost-effective therapeutic strategy for ocular inflammatory diseases.
Project description:OBJECTIVE: To explore the association between epistasis among related genes of the renin-angiotensin system (RAS) and type 2 diabetes. RESEARCH DESIGN AND METHODS: Gene polymorphisms were genotyped in 394 type 2 diabetic patients and 418 healthy control subjects in this case-control study. We used the multifactor dimensionality reduction method to identify gene-gene interactions. RESULTS: No single locus was associated with type 2 diabetes, except for the insert/deletion (I/D) polymorphism of the ACE gene in female subjects. In multi-locus analyses, in male subjects the model of rs2106809 (ACE2), rs220721 (Mas), rs699 (AGT), and I/D (ACE) was significant (P = 0.043). This combination was associated with a 4.00 times (95% CI 2.51-6.38; P < 0.0001) greater prevalence of type 2 diabetes. In female subjects, the model of rs2106809 (ACE2), I/D (ACE), and rs1403543 (AGTR2) was significant (P = 0.012). This three-locus combination was associated with a 2.76 times (1.91-3.97; P < 0.0001) greater prevalence of type 2 diabetes. CONCLUSIONS: Interactions among RAS-related genes were associated with type 2 diabetes in a Chinese population.