ObjectiveTo investigate the effect of echinococcus granulosus protoscolices on the differentiation of bone marrow mesenchymal stem cells (BMSCs) into fibroblasts.MethodsFemur bone marrow of 4-week-old C57BL/6 mice was taken and BMSCs were isolated and cultured by adherent culture. Echinococcus granulosus protoscolices was extracted from the liver of sheep infected with echinococcus granulosus. The experiment was divided into two groups. The experimental group was co-cultured with the 3rd generation BMSCs and the echinococcus granulosus protoscolices, and the control group was the 3rd generation BMSCs. Before and after co-culture, the morphology of BMSCs and the activity of echinococcus granulosus protoscolices were observed by inverted microscope. After cultured for 1, 3, 5, and 7 days, the mRNA expressions of transforming growth factor β1 (TGF-β1), collagen type Ⅰ, and collagen type Ⅲ were detected by real-time fluorescent quantitative PCR, the protein expressions of TGF-β1, collagen type Ⅰ, collagen type Ⅲ, Smad7, and phosphorylated Smad2/3 were detected by Western blot, and the contents of collagen type Ⅰ and collagen type Ⅲ in the supernatant of the two groups were detected by ELISA.ResultsAfter 7 days of co-culture, the morphology of BMSCs changed into fusiform and irregular triangle, which was closer to the mouse fibroblasts. The relative mRNA expressions of TGF-β1, collagen type Ⅰ, and collagen type Ⅲ in the experimental group were significantly higher than those in the control group; the relative protein expressions of TGF-β1, collagen type Ⅰ, collagen type Ⅲ, and phosphorylated Smad2/3 in the experimental group were significantly higher than those in the control group, and the relative protein expression of Smad7 in the experimental group was significantly lower than that in the control group; the contents of collagen type Ⅰ and collagen type Ⅲ in the supernatant of the experimental group were significantly higher than those in the control group. The differences between the two groups were significant (P<0.05).ConclusionEchinococcus granulosus protoscolices may promote the secretion of collagen type Ⅰ, collagen type Ⅲ, and TGF-β1 by TGF-β1/Smad signal pathway, which can promote the fibrosis of BMSCs that related to the formation of fibrocystic wall by echinococcosis.