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Song B.,Shanghai JiaoTong University | Song B.,Shanghai Institute of Hypertension | Jin H.,Shanghai JiaoTong University | Yu X.,Ningbo University | And 17 more authors.
Regulatory Peptides | Year: 2013

Angiotensin (Ang) II plays a vital role in vascular smooth muscle cell (VSMC) growth and proliferation. Angiotensin-converting enzyme 2 (ACE2) is a specific Ang II-degrading enzyme but its role in VSMC proliferation remains largely unknown. We hypothesized that ACE2 might suppress Ang II-mediated oxidative stress and VSMC proliferation. Human umbilical artery smooth muscle cells (HUASMCs) were pretreated with Ang II (100 nM) for 6 h and 24 h, respectively. Exposure to Ang II resulted in significant increases in suppressor of cytokine signaling 3 (SOCS3) expression and phosphorylation levels of JAK2, STAT3 and ERK1/2 linked with elevated superoxide production and cell proliferation in HUASMCs. These changes were strikingly prevented by administration of ERK1/2 inhibitor PD98059 (10 μM) and JAK/STAT inhibitor WP1066 (5 μM) but were largely aggravated by ACE2 inhibitor DX600 (0.5 μM). More importantly, treatment with human recombinant ACE2 (hrACE2; 1 mg/ml) dramatically prevented Ang II-mediated SOCS3 expression and the JAK2-STAT3 and ERK1/2 signaling, and resulted in attenuation of superoxide production and cell proliferation in HUASMCs. Intriguingly, downregulation of profilin-1 with profilin-1 siRNA (50 nM) was able to abolish Ang II-induced upregulations of profilin-1 expression, ERK1/2 phosphorylation and superoxide production with attenuation of VSMC proliferation. In conclusion, treatment with hrACE2 prevents Ang II-mediated activation of the JAK2/STAT3/SOCS3 and profilin-1/MAPK signaling pathways, contributing to attenuation of superoxide generation and cell proliferation in HUASMCs, suggesting a protective mechanism of ACE2 against Ang II-mediated oxidative stress and VSMC proliferation. ACE2 may represent a potential candidate to prevent and treat vascular disorders. © 2013 Elsevier B.V.

Chen L.-J.,Shanghai JiaoTong University | Chen L.-J.,Chinese Academy of Sciences | Xu Y.-L.,Shanghai JiaoTong University | Song B.,Shanghai JiaoTong University | And 11 more authors.
Peptides | Year: 2016

Angiotensin-converting enzyme 2 (ACE2) has been shown to prevent atherosclerotic lesions and renal inflammation. However, little was elucidated upon the effects and mechanisms of ACE2 in atherosclerotic kidney fibrosis progression. Here, we examined regulatory roles of ACE2 in renal fibrosis in the apolipoprotein E (ApoE) knockout (KO) mice. The ApoEKO mice were randomized to daily deliver either angiotensin (Ang) II (1.5 mg/kg) and/or human recombinant ACE2 (rhACE2; 2 mg/kg) for 2 weeks. Downregulation of ACE2 and upregulation of phosphorylated Akt, mTOR and ERK1/2 levels were observed in ApoEKO kidneys. Ang II infusion led to increased tubulointerstitial fibrosis in the ApoEKO mice with greater activation of the mTOR/ERK1/2 signaling. The Ang II-mediated renal fibrosis and structural injury were strikingly rescued by rhACE2 supplementation, associated with reduced mRNA expression of TGF-β1 and collagen I and elevated renal Ang-(1–7) levels. In cultured mouse kidney fibroblasts, exposure with Ang II (100 nmol L−1) resulted in obvious elevations in superoxide generation, phosphorylated levels of mTOR and ERK1/2 as well as mRNA levels of TGF-β1, collagen I and fibronectin 1, which were dramatically prevented by rhACE2 (1 mg mL−1) or mTOR inhibitor rapamycin (10 μmol L−1). These protective effects of rhACE2 were eradicated by the Ang-(1–7)/Mas receptor antagonist A779 (1 μmol L−1). Our results demonstrate the importance of ACE2 in amelioration of kidney fibrosis and renal injury in the ApoE-mutant mice via modulation of the mTOR/ERK signaling and renal Ang-(1–7)/Ang II balance, thus indicating potential therapeutic strategies by enhancing ACE2 action for preventing atherosclerosis and fibrosis-associated kidney disorders. © 2016 Elsevier Inc.

Zhang C.,Guangdong Academy of Medical science and Guangdong Cardiovascular Institute | Huang Y.,Guangdong Academy of Medical science and Guangdong Cardiovascular Institute | Huang T.,Guangdong Academy of Medical science and Guangdong Cardiovascular Institute | Xia C.,Guangdong Academy of Medical science and Guangdong Cardiovascular Institute | And 5 more authors.
Chinese Journal of Cardiology | Year: 2014

Objective: To evaluate the therapy efficacy of iloprost combined with low dose tadalafil in adult congenital heart disease (CHD) patients with severe pulmonary arterial hypertension (PAH). Methods: Adult CHD patients with severe PAH were included and divided into the sequential combination therapy group [iloprost: 10 μg/inhalation, 6 times per day for 6 months, and then add oral tadalafil (5 mg/d) till 12 months, n = 32] and upfront combination therapy group [iloprost: 10 μg/inhalalion, 6 times per day combined with oral tadalafil (5 mg) for 12 months, n =36]. Data on 6 min walking test (6MWT), Borg dyspnea score, oxygen saturation measurement, WHO classification, and cardiac catheterization were obtained at baseline, 6 and 12 months. Results: Seventy-two patients were enrolled in the study and 68 patients completed the study. Pulmonary vascular resistance (PVR) was significantly reduced in the sequential combination therapy group[(12.96 ± 6.48) Wood U vs. (16.94 ± 8.11) Wood U, P < 0.05] and in the upfront combination therapy group [(12.45 ± 7.32) Wood U vs. (16.73 ± 9.28) Wood U, P < 0.05] while pulmonary blood flow [(6.77 ± 3.17) IVmin vs. (5.08 ± 2.36) L/min, P < 0.05; (6.95 ± 3.32) L/min vs. (5.03 ± 2.32) L/min, P < 0.05], the 6 MWD were significantly increased [(458 ± 59) m vs. (427 ± 65) m, P < 0.05; (494 ± 59) m vs. (436 ± 62) m, P < 0.01], the Borg dyspnea score (2.04 ± 0.72 vs. 2.52 ± 0.79, P < 0.05; 1.72 ± 0.73 vs. 2.51 ± 0.77, P < 0.01) was significantly improved in both groups at 6 months compared to baseline levels. In the upfront combination therapy group, venous oxygen saturation [(68.4 ± 9.3)% vs. (62.9 ± 9.5)%, P < 0.05] and systemic oxygen saturation during exercise[(87.2 ± 9.7)% vs. (83.1 ± 15.6)%, P < 0.05] at 6 months were also significantly improved compared to baseline. At month 1.2, significantly lowered pulmonary artery pressure, PVR, Rp/Rs and increased pulmonary blood flow and cardiac index were evidenced in both groups compared to baseline. Conclusion: Iloprost combined with low dose tadalafil regimen can effectively reduce PVR, increase 6MWD, and improve cardiopulmonary function in adults CHD patients with severe PAH. Compared with the sequential therapy regimen, the upfront combination therapy regimen can more rapidly improve the clinical symptoms of patients. Copyright © 2014 by the Chinese Medical Association.

Zhang C.J.,Guangdong Academy of Medical science and Guangdong Cardiovascular Institute | Huang T.,Guangdong Academy of Medical science and Guangdong Cardiovascular Institute | Huang X.S.,Guangdong Academy of Medical science and Guangdong Cardiovascular Institute | Huang Y.G.,Guangdong Academy of Medical science and Guangdong Cardiovascular Institute | And 4 more authors.
Chinese Medical Journal | Year: 2014

Background While echocardiography has been a pivotal screening test in pulmonary arterial hypertension (PAH), the presence of structural cardiac defects may affect the ability to reliably predict pulmonary artery pressures (PAPs). This study sought to evaluate the accuracy of Doppler echocardiography (DE) for estimating PAPs in adult atrial septal defect (ASD) patients with PAH.Methods A prospective study was carried out to compare the echocardiographic assessment of PAP with the same pressures obtained by right heart catheterization (RHC) in adult ASD patients with PAH who underwent simultaneous DE and RHC. Bland-Altman analyses were performed to evaluate the agreement between DE and RHC measurements of PAPs.Results Two hundred and fifty-seven patients were included in the study. A significant overestimation of the systolic pulmonary arterial pressure (sPAP) and mean pulmonary artery pressure (mPAP) was reported by echocardiography compared with those by catheterization ((81.8±26.9) mmHg vs. (72.9±26.9) mmHg, P <0.01; (51.9±16.4) mmHg vs. (41.4±17.2) mmHg, P <0.01, respectively). Twenty-one percent (55/257) of the patients had PAH when estimated by echocardiography whereas showed normal results in the subsequent catheterization test. Using Bland-Altman analytic methods, the bias for the echocardiographic assessment of the sPAP was 9.1 mmHg with 95% limits of agreement ranging from –24.4 to 42.6 mmHg. For mPAP measurement, the bias was 10.5 mmHg with 95% limits of agreement ranging from –12.4 to 33.4 mmHg. On multiple linear regression analysis, age, gender, body surface area, ASDs’ diameter, PVR, diastolic blood pressure, and echocardiographic assessment of right atrial pressure (RAP) explained 68.8% of the total variability in the model (r2=0.688, P <0.01).Conclusion Inaccuracy was frequently reported in Doppler echocardiographic assessment of the PAP in adult ASD patients with PAH and was often associated with age, gender, body surface area, ASDs’ diameter, pulmonary vascular resistance, diastolic blood pressure and echocardiographic estimation of RAP. © 2014, Chinese Medical Association, All rights reserved.

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