Resarch On Roles Of TGF-β1 And PDGF-B On The TLR4 Signaling Pathways

TGF-β1 and PDGF-B were prominently up-regulate and inflammatory mediators were secreted on TLR4 signaling of LPS-stimulated mouse mammary epithelial cells(MECs), which will play important roles in innate immunity and inflammatory responses. In order to study whether the TGF-β1 and PDGF-B are the possible key genes of TLR4 signaling pathways in the mouse MECs. The TGF-β1 and PDGF-B genes were transfected with RNA interference, then the transfection efficiency were detected by real-time quantitative RT-PCR. Meanwhile, the mRNA of Smad3 and PI3 K were detected with the same method. The concentration of Smad3, PI3 K, IL-6 and TNF-α in the mouse MECs were measured by ELISA.Results: The different concentration of TGF-β1-mus-1212、PDGF-B-mus-886 siRNA(50 nM、30 nM、20 nM) can significantly inhibited their mRNA expression. Compared with the concentration of TGF-β1-mus-1212、PDGF-B-mus-886 in 30 nM and 20 nM, the 50 nM has a higher transfection rate, repectively. When the mouse MECs was transfected with siRNA of TGF-β1 and stumilated with LPS, compared with the control group, the Smad3 mRNA and protein expression level in cells were reduced significantly(P < 0.05), the TNF-α secretion of mouse MECs was significantly reduced(P<0.05), and there was no change(P>0.05) on the IL-6 level in each group. When the mouse MECs was transfected with siRNA of PDGFB and stumilated with LPS, compared with the control group, the PI3 K mRNA and expression level in cells were reduced significantly after the silence of PDGF-B gene(P<0.05), PI3 K protein reduced was not prominently difference(P>0.05). The IL-6 secretion of mouse MECs was prominently reduced(P<0.05), but there was no change(P>0.05) on the TNF-α level in each group.Conclusion: The TGF-β1 and PDGF-B gene could transfected successfully by siRNA. The Smad3 that is signaling pathways downstream of TGF-β1 is affected directly in the mouse MECs after the silence of TGF-β1 gene, and inflammatory mediators can be secreted by LPS-induced, TGF-β1 may be the key gene during the pathway of TLR4 in the mouse MECs. The PI3 K that is signaling pathways downstream of PDGF-B is affected indirectly in the mouse MECs after the silence of PDGF-B gene, and inflammatory mediators can be secreted by LPS-induced. PDGF-B may be the key gene during the pathway of TLR4 in the mouse MECs. The TGF-β1 and PDGF-B should be continued studied as a target gene and for the treatment of mammary gland inflammation, tumor and other related mammary gland disease to provide new train of thought and the experimental data, provide theoretical basis for the development and application of new drugs.