The Effect Of Peroxiredoxin-1 On Ang Ⅱ Induced Cardiomyocytes Hypertrophy

Objective:To innovatively investigate the expression of Peroxiredoxin-1(Prx-1) in cardiomyocytes hypertrophy caused by Angiotensin II(Ang II) stimulation, and the influence of Prx-1overexpression on reactive oxygen species(ROS)、Akt signaling pathway activation as well as cardiomyocytes hypertrophy stimulated by Ang II. The aim is to explore whether ROS/Akt signal transduction pathway is mediated Ang II-induced cardiomyocytes hypertrophy. Of importance, we firstly found that the inhibitive effect of Prx-1 on Ang II-induced cardiomyocytes hypertrophy is by inhibition of ROS/AKT signaling pathway activation.Methods:(1) To investigate the expression of BNP、ROS and Prx-1 in cardiomyocytes hypertrophy induced by Ang II stimulation. Cultured cardiomyocytes were randomly divided into control and Ang II groups. Brain Natriuretic Peptide(BNP) m RNA were measured by Real-time PCR when Ang II stimulated 3h、6 h、12 h、24 h、48h �'�72h. reactive oxygen species(ROS) were measured by DCFH-DA when Ang II stimulated 10min、20min、30min、1h、2h �'� 4h; while Prx-1 expression was by western blot when Ang II stimulated 30 min、1h、2h、4h �'� 8h.(2) Using the Prx-1 liposome infection, Prx-1 was overexpressed in cardiomyocytes, next we observed the expression of BNP、ROS and p-Aktser473 in cardiomyocytes hypertrophy induced by Ang II. Cultured cardiomyocytes were randomly divided into four groups, 1) control; 2) Ang II; 3) Ang II +vehicle(plasmid without Prx-1 gene). 4) Ang II +Prx-1 plasmid. Specific plasmid including Prx-1 gene was transfected into cardiomyocytes using the liposome infection. Western blot was used to evaluate the expressions of Prx-1 and p-Aktser473 when Ang II stimulated 2h or 1h in the latter three groups respectively. The levels of BNP m RNA were measured by Real-time PCR when Ang II stimulated 24 h in the latter three groups, and ROS was by DCFH-DA when Ang II stimulated 20 min in the latter three groups.Results:(1) ① Compared with control, BNP m RNA expression increased 1.04±0.04 folds, 1.06±0.05 folds, 1.22±0.17 folds, 1.68±0.33 folds(P<0.05), 2.12±0.45 folds(P<0.05) and 2.86±0.52 folds(P<0.05) respectively when Ang II stimulated 3h、6 h、12 h、24 h、48h and 72 h. ② The level of ROS in control was 3673±343, while it increased to 4325±136(P<0.05), 4742±271(P<0.05), 4675±355(P<0.05), 4155±364, 4047±208 and 3580±382 respectively when Ang II stimulated 10min、20min、30min、1h 、 2h and 4h. ③ The level of Prx-1 was 0.18±0.05, while it increased to 0.30±0.07(P<0.05), 0.41±0.12(P<0.05), 0.49±0.09(P<0.05), 0.38±0.05(P<0.05) and 0.33±0.07(P<0.05) when Ang II stimulated 30 min、1 h、2h、4h and 8h.(2) ①The expression of Prx-1 protein in control group was 0.27±0.03, which was no difference with vehicle group(0.30±0.05, p>0.05).The expression of Prx-1 protein in transfected cardiomyocytes(0.80±0.15) was significantly higher than vehicle(p<0.05). ②Compared with the control group, the expressions of BNP m RNA in Ang II group、Ang II +vehicle group, Ang II +Prx-1 plasmid group were increased respectively 1.70±0.25 folds(P<0.05), 1.83±0.28 folds and 1.35±0.24 folds respectively. Compared with Ang II group, the changes of BNP m RNA in Ang II +vehicle group was not significant(P>0.05) but it is lower in Ang II +Prx-1 plasmid group(P<0.05).③Compared with the control group(3648±302), the level of ROS in Ang II group was significantly higher(4688±284, p>0.05). Compared with Ang II group, ROS in Ang II +vehicle group(4576±343) not significant(P>0.05), but it is lower in Ang II +Prx-1 plasmid group(3824±255)(P<0.05).④Compared with the control group(0.25±0.03), the expressions of Prx-1 in Ang II group was significantly higher(0.70±0.11,(P<0.05). Compared with Ang II group, Prx-1 in Ang II +vehicle group was no changed(0.77±0.18, P>0.05), but it was further higher in Ang II +Prx-1 plasmid group(1.56±0.24, P<0.05). ⑤Compared with the control group(0.33±0.05), the expressions of p-Akt in Ang II group was significantly higher(0.92±0.15, P<0.05). Compared with Ang II group, p-Akt in Ang II +vehicle group was no changed(0.86±0.18, P>0.05), but it was lower in Ang II +Prx-1 plasmid group( 0.56±0.12,P<0.05).Conclusion: 1.Prx-1 was outstandingly up-regulated in cardiomyocytes hypertrophy induced by Angiontensin II, so dose the ROS and p-Akt ser473.2.Prx-1 was overpressed in cardiomyocytes via Prx-1 liposome infection; over-expressed Prx-1 strikingly held up cardiomyocytes hypertrophy as well as the expression of ROS and p-Akt ser473. 3.Ang II may induces cardiomyocytes hypertrophy by ROS/Akt pathway; while Prx-1 may inhibits Akt pathway activation by decreasing ROS level, and then restrains cardiomyocytes hypertrophy caused by Ang II stimulation.