ABSTRACT
Objective:
To investigate the relationship between the level of
oxidative stress and the expression of
intermediate conductance calcium activated potassium channel (KCa3.1)
protein in the cardiac
fibroblasts (CFs) during
hypertension process,and to clarify the
role of KCa3.1 in cardiac
fibrosis and its mechanism.
Methods:
The CFs of
male C57B6 and AGT-REN double transgenic
hypertension (dTH)
mice were cultured and the wild C57B6
mouse CFs were used as
control group.The CFs of dTH
mice were randomly divided into
high blood pressure group (dTH) and N-acetyl
cysteine group (NAC).The CFs were treated with different concentrations of NAC for 24 h.The
cell proliferation was detected by MTT and double dichlorofluorescein (DCFH-DA) probe was used for the
detection of cellular
reactive oxygen species (ROS) expression;
Western blotting was employed to detect the expressions of
collagen Ⅰ,
collagen Ⅲ,Kca3.1 channel
protein and the changes of PI3K signaling pathway
protein phosphorylation.
Results:
The ROS
production and
protein expression of Kca3.1 channel of the dTH
mice on 4,8,12 months were increased compared with 2 months (P<0.05 or P<0.01);the results of MTT suggested that the proliferation rates of CFs were 165.9%,138.72%,110.92% and 109.82% after
administration of 1×10-6,1× 10 5,1× 10 4 and 1 × 10-3 mol · L-1 NAC in the dTH
mice,and 1 × 10-4 and 1 × 10 3 mol · L-1 NAC significantly inhibited the proliferation of CFs.Compared with
control group,the
secretion of
collagen Ⅰ and Ⅲ of CFs in the TH
mice was decreased in 1 × 10-4 mol · L-1 NAC group (P<0.01).The results of
Western blotting showed that compared with
control group,the expression level of Kca3.1 channel
protein in CFs of the TH
mice in 1 × 10-4 mol · L-1 NAC group was decreased (P<0.01).Compared with
control group,the p-AKT/T-AKt in CFs of the dTH
mice was increased (P<0.01);but in NAC group,the p-AKT/T-AKt was lower than that in dTH group (P<0.01).
Conclusion:
NAC can inhibit the expression of KCa3.1 channel
protein in CFs of the dTH hypertensive
mice,which may be related to increasing the
phosphorylation of AKt/PI3K signaling pathway.