Objective To explore the effect and mechanism of anti-mesangial cell-proliferation-peptide 2(AMPP2)on mesangial cell proliferation induced by transforming growth factor β1(TGF-β1).Methods Mesangial cells were cultured in vitro and treated with TGF-β1(10 μg/L)and AMPP2(10 ng/L).According to different intervention factors,mesangial cells were divided into four groups:the control group,the AMPP2 group,the TGF-β1 group and the TGF-β1+AMPP2 group.The proliferation activity of mesangial cells was detected by CCK-8.The relative protein expression of cyclin dependent kinase 4(CDK-4),cyclin dependent kinase 6(CDK-6),proliferating cell nuclear antigen(PCNA),α-smooth muscle actin(α-SMA),collagen-Ⅰ(COL-Ⅰ)and fibronectin(FN)were examined by Western blot assay.The relative mRNA expression of α-SMA,COL-Ⅰ and FN were detected by qPCR.Results Compared with the control group,proliferation activity of mesangial cells was significantly increased in the TGF-β1 group(P＜0.05).The proliferation activity of mesangial cells was markedly decreased in the TGF-β1+AMPP2 group compared with that of the TGF-β1 group(P＜0.05).Compared with the control group,protein levels of CDK-4,CDK-6,PCNA,α-SMA,COL-Ⅰand FN in cells were significantly increased in the TGF-β1 group(P＜0.05),as well as the mRNA levels of α-SMA,COL-Ⅰand FN(P＜0.05).In the TGF-β1+AMPP2 group,the protein and mRNA levels of α-SMA,COL-Ⅰand FN and the protein levels of CDK-4,CDK-6 and PCNA were markedly decreased compared with those of the TGF-β1 group(P＜0.05).Compared with the control group,levels of p-SMAD3/SMAD3 was remarkably upregulated in the TGF-β1 group(P＜0.05),while levels of p-SMAD3/SMAD3 was remarkably downregulated in the TGF-β1+AMPP2 group compared with those of the TGF-β1 group(P＜0.05).Conclusion AMPP2 may inhibit mesangial cell proliferation by regulating TGF-β1/SMAD3 pathway.

E2 is a recombinant hepatitis E virus capsid protein including its main antigenic determinants but lacking of the particle assembling domain. P239 was the C-terminal extending protein of E2 and could self-assemble to form virus like particles, which might serve as mimicry of virions both structurally and antigenically. We previously used yeast two-hybrid system to screen proteins interacting with E2 based on a human hepatocyte cDNA library. One candidate was identified as the segment (aa388-437) of cytochrome P450 2A6 protein, which is predominantly expressed in liver and important for metabolization. Some studies have demonstrated that hepatitis virus infection may altered cell metabolic clearance of coumrarin which were rapidly matebolised by CYP2A6. In this research, we demonstrated that the protein interaction between HEV capsid proteins and CYP2A6 by pull-down and co-immunoprecipitation. It was also found that their interaction could decrease the CYP2A6 catalytic activity when p239 was incubated within the CYP2A6-transfected Huh7 cells. These results suggested that CYP2A6 might be related to the pathological process when HEV invaded host cells.
Aryl Hydrocarbon Hydroxylases ; genetics ; metabolism ; Capsid Proteins ; genetics ; metabolism ; Cell Line, Tumor ; Coumarins ; metabolism ; Cytochrome P-450 CYP2A6 ; Hepatitis E virus ; metabolism ; Humans ; Imidazoles ; metabolism ; Immunoprecipitation ; Protein Binding ; Recombinant Proteins ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction