TGF-β1、BMP-7及Gremlin在小鼠肝纤维化组织中的表达

Expressions of TGF-β1, BMP-7 and Gremlin in CCl4-induced liver fibrosis tissue of mice

摘要:

目的研究四氯化碳（CCl4）诱导小鼠肝纤维化组织中转化生长因子β1（TGF-β1）、骨形态发生蛋7（BMP-7）及Gremlin的表达，探讨其在肝纤维化发生机制中的作用。方法雄性C57小鼠40只，分为实验组和对照组，每组20 只。实验组给予腹腔注射40% CCl4橄榄油溶液，10 ml/kg；对照组腹腔注射橄榄油溶液，10ml/kg，2 次/ 周，持续8 周。苏木精-伊红染色后观察肝纤维化程度，免疫组织化学法染色后分析TGF-β1、BMP-7 及Gremlin 在肝纤维中组织中的表达和分布，实时荧光定量聚合酶链反应和Western blot检测TGF-β1、BMP-7 及Gremlin 在正常和纤维化肝组织中mRNA 和蛋白的表达。结果TGF-β1和Gremlin 在肝纤维化组织中mRNA 和蛋白表达增强（p <0.05），而BMP-7 在肝纤维化组织中表达降低（p <0.05）。结论TGF-β1、Gremlin的表达与肝纤维化呈正相关，BMP-7与肝纤维呈负相关（ <0.05）。Gremlin可能通过下调BMP-7 的表达，诱导肝纤维化的发生。

Abstract:

Objective To study the expressions of transforming growth factor-beta 1 (TGF-β1), bone morphogenetic protein 7 (BMP-7) and Gremlin in the liver fibrosis induced by carbon tetrachloride (CCl4) in mice, and to investigate their roles in the pathogenesis of hepatic fibrosis. Methods Forty male C57 mice were randomly divided into control group and experimental group. In the experimental group, acute liver injury of mice was induced by intraperitoneal injection of 40% CCl4 olive oil solution, 10 ml/kg, while the control group was injected with olive oil, twice a week for 8 weeks. After 8 weeks the mice were sacrificed,and the liver tissue was fixed. Hematoxylin-eosin (HE) staining was used to observe the degree of liver fibrosis. The expressions and distribution of TGF-β1, BMP-7 and Gremlin in the control and experimental groups were detected through immunohistochemical staining. qR-PCR detecting system and Western blot were utilized for detection of mRNA and protein expressions of TGF-β1, BMP-7 and Gremlin in the normal and fibrotic liver tissues. Results In the experimental group, both mRNA and protein expressions of TGF-β1 and Gremlin in the liver fibrosis tissue were significantly enhanced (p < 0.05). However, the expression of BMP-7 in the liver fibrosis tissue was significantly decreased (p < 0.05). The expression levels of TGF-β1 and Gremlin were positively related to hepatic fibrosis, while BMP-7 was negatively correlated to hepatic fibrosis (p < 0.05). Conclusions Gremlin may induce the occurrence of liver fibrosis by down-regulation of BMP-7 expression.