Dynamic expression of putative receptor protein related to the angiotensin type 1 receptor in postnatal mouse cochlear hair cells and spiral ganglion neurons / 解剖学报

Objective To study the temporal and spatial expressions of G protein-coupled receptor, putative receptor protein related to angiotensin type 1 receptor (APJ), in mammal cochlea postnatal development. Methods The cochlear tissues of each group 11 C57BL/ 6 mice at postnatal day 7 (P7), P14, P28 and postnatal month 2(P2M) were taken out under a stereo microscope. Real-time PCR, Western blotting and immunofluorescent staining were used to detect the expressions of APJ in hair cells and spiral ganglion neurons. Results The expression pattern of APJ in cochleae showed an upward trend during the period from P7 to P2M. The temporal expressions of APJ in hair cells and spiral ganglion neurons increased obviously at P14 and P2M. The spatial expression patterns of APJ in hair cells and spiral ganglion neurons followed a declined gradient from base turns to apex turns at P14. Conclusion APJ expression exhibits a specific spatial and temporal pattern during mouse cochlea postnatal development, and may play a role in cochleae maturation and hearing formation.

Mechanism of angiotensin II (Ang II) on the proliferation of human hepatoma cell line HepG2 cells / 中华肝脏病杂志

Objective@#To study the effect and mechanism of angiotensin (Ang II) on the proliferation of human hepatocellular carcinoma HepG2 cells.@*Methods@#The effects of different concentrations of Ang II's (10-8-10-4 mol/L) on proliferated hepatocellular carcinoma HepG2 cells were detected by CCK-8 assay. The expression of angiotensin II type 1 receptor (AT1) protein and activation of ERK1/2 protein in hepatocellular carcinoma HepG2 cells after processing with Ang II were assayed by Western blot. The cells were pretreated with candesartan (AT1 receptor antagonist), sorafenib (Raf kinase inhibitor) and PD98059 (ERK1/2 inhibitor) for 1.5 h and then Ang II (10-6 mol/L) was added. CCK-8 assay was used to determine whether it could reverse the proliferation of Ang II, and ERK phosphorylation levels were detected by Western blot. The changes in Bcl-2 and c-myc gene expression before and after Ang II processing were detected by Rt-PCR. According to different data, t-test, one-way analysis of variance or SNK method were used for statistical analysis.@*Results@#HepG2 cells treated with different concentrations of Ang II promoted cell proliferation after 24h and 48h. After 24 h, cell vitality was strongest with Ang II concentration 10-5 mol/L and the absorbance value was 0.990 8±0.097 8; and again after 48 h, the cell viability was strongest with Ang II concentration 10-6 mol/L and the absorbance value was 1.302 7 ± 0.030 9. Moreover, the pro-proliferation effect of Ang II on HepG2 cells blocked candesartan, sorafenib and ERK1/2 isolated inhibitors. After treatment with 10-6 mol/L Ang II, Western blot showed that Ang II significantly promoted AT1 receptor expression and phosphorylation of ERK1/2 protein confirmed that Ang II activated the AT1/RAF/ERK1/2 signaling pathway. In addition, Rt-PCR detection showed that the downstream of Bcl-2 and c-myc genes expressions rose significantly when the concentration of Ang II ranged from 10-8 to 10-6 mol/L.@*Conclusion@#Ang II can promote the proliferation of HepG2 cells by activating AT1/Raf /ERK1/2 signaling pathway and enhance the downstream of Bcl-2 and c-myc gene expression.

Comparative effects of angiotensin II and angiotensin-(4-8) on blood pressure and ANP secretion in rats

Angiotensin II (Ang II) is metabolized from N-terminal by aminopeptidases and from C-terminal by Ang converting enzyme (ACE) to generate several truncated angiotensin peptides (Angs). The truncated Angs have different biological effects but it remains unknown whether Ang-(4-8) is an active peptide. The present study was to investigate the effects of Ang-(4-8) on hemodynamics and atrial natriuretic peptide (ANP) secretion using isolated beating rat atria. Atrial stretch caused increases in atrial contractility by 60% and in ANP secretion by 70%. Ang-(4-8) (0.01, 0.1, and 1 µM) suppressed high stretch-induced ANP secretion in a dose-dependent manner. Ang-(4-8) (0.1 µM)-induced suppression of ANP secretion was attenuated by the pretreatment with an antagonist of Ang type 1 receptor (AT₁R) but not by an antagonist of AT₂R or AT₄R. Ang-(4-8)-induced suppression of ANP secretion was attenuated by the pretreatment with inhibitor of phospholipase (PLC), inositol triphosphate (IP₃) receptor, or nonspecific protein kinase C (PKC). The potency of Ang-(4-8) to inhibit ANP secretion was similar to Ang II. However, Ang-(4-8) 10 µM caused an increased mean arterial pressure which was similar to that by 1 nM Ang II. Therefore, we suggest that Ang-(4-8) suppresses high stretch-induced ANP secretion through the AT₁R and PLC/IP₃/PKC pathway. Ang-(4-8) is a biologically active peptide which functions as an inhibition mechanism of ANP secretion and an increment of blood pressure.

Correlation between anti-angiotensin type 1 receptor antibody and prognosis of sensitized renal transplant recipients / 中华器官移植杂志

Objective To evaluate the correlation between anti-angiotensin type 1 receptor (AT1R) antibody and the prognosis of HLA-positive sensitized renal transplant recipients.Methods Forty-three HLA-positive sensitized recipients positive for AT1R antibodies were tested.HLA antibodies were tested by Lurninex-based single antigen beads assay.AT1R antibody was detected by ELISA.The patients were divided into two groups according to AT1R antibody level:AT1R-AA positive group (AT1R-AA ≥9 U/mL,n =12) and AT1R-AA negative group (AT1R-AA＜9 U/mL,n =31).We also analyzed the rate of rejection and allograft loss,HLA antibodies level,kidney function,kidney survival and patients' survival,etc.Results The rate of allograft loss in the AT1RAA positive group and the AT1R-AA negative group was 41.7％ (5/12) and 9.6％ (3/31)respectively (P =0.02).The rate of AMR in the AT1R-AA positive group and the AT1R-AA negative group was 25％ (3/12) and 0.0％ (0/31) respectively (P =0.03).Meanwhile,the one-yearpatients' survival in the AT1R-AA positive group was lower than in the AT1R-AA negative group (P＜0.05).There was no significant association between AT1R-AA (mean AT1R-AA =8.7 U/mL)and MFI (mean MFI =9119).AT1R antibody was one of risk factors to acute antibody-mediated rejection and kidney allograft loss for sensitized recipients.Conclusion The rate of allograft loss in the AT1R-AA positive group and the AT1R-AA negative group was 41.7％ (5/12) and 9.6％ (3/31)respectively (P =0.02).The rate of AMR in the AT1R-AA positive group and the AT1R-AA negative group was 25％ (3/12) and 0.0％ (0/31) respectively (P =0.03).Meanwhile,the one-yearpatients' survival in the AT1R-AA positive group was lower than in the AT1R-AA negative group (P ＜0.05).There was no significant association between AT1R-AA (mean AT1R-AA =8.7 U/mL)and MFI (mean MFI =9119).AT1R antibody was one of risk factors to acute antibody-mediated rejection and kidney allograft loss for sensitized recipients.

The Role of Serum RGS2 Protein,Ang Ⅱ and AT1R in the Pathogenesis of Pre-eclampsia / 实用妇产科杂志

Objective:To investigate the role of serum RGS2 protein,Ang Ⅱ and AT1R in the Pathogenesis of Preeclampsia and it's impact on the severity of the disease.Methods:Totally 50 patients with PE collected from Shenzhen Maternity and Child Healthcare Hospital,Southern Medical University during October 2015-September 2016 were recruited as PE group(PE with FGR group 17 cases and PE without FGR group 33 cases),40 cases of healthy pregnant women were collected as the control group.ELISA was used to detect the serum RGS2 protein,Ang Ⅱ and AT1R levels.he differences between the groups were compared.Logistic regression was used to analyze the correlation between the three indexes and the severity of PE.Results:①In PE group plasma RGS2 protein,Ang Ⅱ,AT1R levels and systolic blood pressure,diastolic blood pressure,sampling gestational age,maternal gestational age,neonatal birth weight were higher than those in control group(P ＜ 0.05);There was no significant difference on RGS2 protein level,systolic blood pressure and diastolic blood pressure between PE with FGR group and PE without FGR group(P＞0.05),There was significant difference on the Ang Ⅱ,AT1R level and newborn weight(P ＜ 0.05).②Logistic regression analysis showed that RGS2 、Ang Ⅱ and AT1R were the independent risk factors of PE.(the crude odds ratio of RGS2,Ang Ⅱ and AT1R were ＞ 1,P ＜ 0.05.After adjust the sampling of gestational age the OR values were ＞ 1,P ＜0.05.After adjust the other two indicators the OR values were ＞ 1,P ＜0.05,except for Ang Ⅱ.).③RGS2 protein,Ang Ⅱ,AT1R levels were positively correlated with PE,systolic and diastolic blood pressure(P ＜ 0.05).Ang Ⅱ,AT1R levels were negatively correlated with neonatal birth weight (P ＜ 0.05).RGS2 was not related with neonatal birth weight (P ＞ 0.05).Conclusions:Plasma RGS2 protein,Ang Ⅱ and AT1R may be associated with the pathogenesis of PE and Ang Ⅱ and AT1R may be associated with the severity of the disease.

Effects of electroacupuncture on postoperative cognitive dysfunction and AngⅡ/AT1R in the hippocampus in aging rats induced by D-galactose / 中国针灸

<p><b>OBJECTIVE</b>To observe the effects of electroacupuncture (EA) on postoperative cognitive dysfunction (POCD) and AngⅡ/AT1R in the hippocampus in D-galactose-induced aging rats which received hepalobectomy, and to explore the possible mechanism of EA on POCD.</p><p><b>METHODS</b>Eighty male Sprague-Dawley rats were randomly divided into a young control group (10 rats), a D-Galactose-induced aged (Da) group (10 rats), a Da+hepatolobectomy group (30 rats) and an EA group (30 rats). The rats in the Da+hepatolobectomy group and EA group were further randomly divided into a 1 d subgroup, 3 d subgroup and a 7 d subgroup, 10 rats in each subgroup. The rats in the EA group were treated with EA at "Baihui" (GV 20) and "Dazhui" (GV 14) with continuous wave (15 Hz in frequency and 1 mA in intensity), and rats in each subgroup were treated for 1 d, 3 d and 7 d, respectively. The rats in the remaining groups were treated with immobilization, once a day. The Y-maze was used to observe the behavior change of rats, and ELISA was applied to measure the level of hippocampal AngⅡ, and RT-PCR and immunohistochemistry method were performed to detect AT1R mRNA expressions and AT1R positive expression in the hippocampus.</p><p><b>RESULTS</b>The number of rat initiative avoidance in the Da group was significantly less than that in the young control group (<0.05), and the mRNA expression and positive percentage of AT1R in the hippocampus in the Da group were significantly higher than those in the young control group (both<0.01). Compared with the Da group, the number of rat initiative avoidance in each subgroup of Da+hepatolobectomy group and EA group were significantly reduced (all<0.01), and the expression of AngⅡ, AT1R mRNA and AT1R positive cells percentage in the hippocampus were significantly increased (<0.05,<0.01). The number of rat initiative avoidance in each subgroup of EA group was higher than that in the subgroup of Da+hepatolobectomy group (<0.05,<0.01); and the expression of AngⅡ, AT1R mRNA, and AT1R positive percentage in the EA group were significantly less than that in the Da+hepatolobectomy group (<0.05,<0.01).</p><p><b>CONCLUSIONS</b>EA at "Baihui" (GV 20) and "Dazhui" (GV 14) could improve POCD in D-galactose-induced aging rats which received hepalobectomy, and it is likely to be related with the inhibition of AngⅡ, AT1R positive expression and AT1R mRNA in the hippocampus.</p>

Antihypertensive Effects of Extract from Flower Buds of Coreopsis tinctoria on Spontaneously Hypertensive Rats / 中草药·英文版

Objective: To provide experimental evidence for the antihypertensive activity of the flavonoids in flower buds of Coreopsis tinctoria (CT-F) and to investigate the underlying mechanism. Methods: The spontaneously hypertensive rats (SHRs) were divided into model, captopril (positive control), and CT-F groups, and the Wistar-Kyoto rats were set as control group, eight in each group. The blood pressure of SHRs, the activity of angiotensin II (Ang-II) in plasma, nitric oxide (NO), malondialdehyde (MDA) and thoracic aorta media thickness in SHRs were measured by tail-cuff method, radioimmunity method, nitrate reductase method, thibabituric acid (TBA) method, and the hematoxylin-eosin staining method. Q-PCR analysis was performed to determine the relative quantity of angiotensin-converting enzyme (ACE), ACEII, angiotensin type 1 receptor (AT1R), and TGF-β1 mRNA in left ventricle. Results: CT-F could lower the systolic blood pressure of SHRs dramatically (P < 0.01). The levels of MDA in serum and Ang II in plasma of SHRs treated with CT-F decreased markedly (P < 0.05, 0.01), the level of NO in serum increased significantly (P < 0.01). In addition, thoracic aorta media thickness in SHRs treated with CT-F was thinner than that of the model group (P < 0.05). The mRNA expression of ACE, AT1R, and TGF-β1 in left ventricle was markedly decreased (P < 0.05), while that of ACE II was increased (P < 0.05). Conclusion: CT-F is effective to lower the blood pressure of SHRs, and its antihypertensive effect is probably associated with lowering the oxidative stress by reducing MDA, ameliorating aorta remodeling, dilating vessel by increasing NO and decreasing Ang-II, and regulating the expression of rennin-angiotensin System-related various genes. © 2014 Tianjin Press of Chinese Herbal Medicines.