Alveolar echinococcosis protoscolices inhibits the differentiation of bone marrow mesenchymal stem cells into fibroblasts / 中国组织工程研究

ABSTRACT

BACKGROUND: The biological characteristics of hepatic alveolar echinococcosis are similar to cancer lesions. Its biological characteristics of invasive growth and metastasis increase the difficulty of surgery. The fibrosis of the outer capsule wall can inhibit the growth of echinococcus multilocularis and keep the disease in the quiescent stage. The role of mesenchymal stem cells in the fibrosis of the outer capsule wall of echinococcosis remains unclear. OBJECTIVE: To investigate the effect of alveolar echinococcosis protoscolices on the differentiation of mesenchymal stem cells into fibroblasts. METHODS: Bone marrow mesenchymal stem cells were isolated from femur bone marrow of 4-week-old C57BL/6 mice, and cultured by adherent method. Alveolar echinococcosis protoscolices were extracted from gerbils infected with alveolar echinococcus. The experiment was divided into three groups. The alveolar echinococcosis group was co-cultured with the third generation of bone marrow mesenchymal stem cells and the protocephalus of alveolar echinococcosis protoscolices. The Echinococcus granulosus group was co-cultured with the third generation of bone marrow mesenchymal stem cells and the protocephalus of Echinococcus granulosus protoscolices. The simple control group was cultured with the third generation of bone marrow mesenchymal stem cells. At 1, 3, 5, and 7 days of cultivation, the real-time fluorescent quantitative PCR was used to detect collagen type I, collagen type III, transforming growth factor-beta 1 and Smad7 gene expression. Western blot assay was utilized to determine collagen type I, collagen type III, Smad7 and phosphorylated Smad2/3 protein expression. ELISA was applied to measure supernatant collagen type I and collagen type III contents. RESULTS AND CONCLUSION: (1) Real-time fluorescent quantitative PCR detection displayed that transforming growth factor-beta 1, collagen type I, collagen type III mRNA relative expression levels were significantly lower in the alveolar echinococcosis group than in the Echinococcus granulosus group and simple control group (P < 0.05). Smad7 mRNA relative expression was significantly higher in the alveolar echinococcosis group than in the Echinococcus granulosus group and simple control group (P < 0.05). (2) Western blot assay showed that collagen type I, collagen type III and phosphorylated Smad2/3 protein relative expression levels were significantly lower in the alveolar echinococcosis group than in the Echinococcus granulosus group and simple control group (P < 0.05). Smad7 protein relative expression was significantly higher in the alveolar echinococcosis group than in the Echinococcus granulosus group and simple control group (P < 0.05). (3) ELISA exhibited that supernatant collagen type I and collagen type III contents were significantly lower in the alveolar echinococcosis group than in the Echinococcus granulosus group and simple control group (P < 0.05). (4) Alveolar echinococcosis protoscolices may promote bone marrow mesenchymal stem cells to secrete Smad7, inhibit the collagen type I, collagen type III and transforming growth factor-beta 1 through the transforming growth factor-beta/Smad signaling pathway, thereby inhibiting the fibrosis of bone marrow mesenchymal stem cells.