[Regulatory effect of Qianliexiao Decoction on TGF-β1, Smad4 and Smad 7 signaling pathways and the proliferation and apoptosis of prostate fibroblasts in mice with experimental autoimmune prostatitis].

OBJECTIVE

To study the effect of intervening in the signal transduction pathways of TGF-β1, Smad4 and Smad7 with Qianliexiao Decoction (QLX) on the proliferation and apoptosis of prostate fibroblasts (PrF) in mice with experimental autoimmune prostatitis (EAP).

METHODS

A model of EAP with damp-heat syndrome was established in C57BL/6 mice by immunization induction combined with the TCM modeling method. The prostate tissue of the mice was harvested for isolation, culturing and purification of PrFs and detection of their purity. After modeling by stimulation with a medium containing >90%-purity or 5 ng/ml TGF-β1, the PrFs in the logarithmic growth phase were obtained and randomly divided into a blank control (serum-free medium), a model control, a positive control (medium containing 5 ng/ml TGF-β1), a low-dose QLX (serum containing 5% QLX), a medium-dose QLX (serum containing 10% QLX), and a high-dose QLX group (serum containing 20% QLX). After 24 hours of intervention, the proliferation of the PrFs was measured, the protein expressions of TGF-β1, Smad4, Smad7, p-Smad4 and p-Smad7 detected by Western blot, their mRNA expressions determined by qPCR, and the apoptosis of the PrFs examined by flow cytometry.

RESULTS

After induction with TGF-β1, the proliferation of the PrFs was significantly increased in the positive control (P < 0.05), but inhibited in the medium- and low-dose QLX groups (P < 0.05) and even more significantly in the high-dose QLX group as compared with that in the model control (P < 0.01). The expressions of Smad4, p-Samd7 and TGF-β1 proteins in the PrFs were remarkably higher in the positive control than in the model control group (P < 0.05), while those of p-Smad4 and TGF-β1 markedly lower (P < 0.01) and that of p-Smad7 dramatically higher in the QLX intervention groups than in the positive control (P < 0.01), in an evident dose-dependent manner. In comparison with the model control group, the high-dose QLX group exhibited a significant decrease in the mRNA expression of Smad4 (P < 0.05) but all the three QLX groups showed a dramatic increase in those of Smad7 (P < 0.05) and TGF-β1 (P < 0.01). The mRNA expression of Smad4 was markedly down-regulated in the high-dose QLX group compared with that in the positive control (P < 0.05), that of Smad7 up-regulated in the model control and QLX groups (P < 0.01), and that of TGF-β1 down-regulated in the three QLX groups (P < 0.01). The apoptosis rate of the PrFs was significantly higher in the QLX groups than in the model control (P < 0.05) in a dose-dependent manner, but showed no statistically significant difference between the model control and the positive control groups (P > 0.05).

CONCLUSIONS

TGF-β1 can stimulate the proliferation of PrFs, up-regulate the expressions of TGF-β1 and p-Smad4, and down-regulate that of p-Smad7, while QLX can inhibit the proliferation of PrFs in a dose-dependent manner by decreasing the expressions of TGF-β1 and p-Smad4, increasing that of p-Smad7, and thereby suppressing TGF-β1-induced proliferation of PrFs.