转化生长因子β_1和核心蛋白聚糖在胰腺星状细胞中的表达

Expression of Transforming Growth Factor B_1 and Decorin in Pancreatic Stellate Cells

背景:胰腺星状细胞(PSCs)在胰腺纤维化的进程中具有重要作用,因此有必要对影响该细胞活化的细胞因子进行研究。目的:建立一种从大鼠中分离、培养PSCs的成熟方法,研究原代培养2～3代的传代PSCs中转化生长因子(TGF)-β1及其拮抗剂核心蛋白聚糖的mRNA(转录水平)和蛋白(翻译水平)的表达和分布。方法:取大鼠胰腺组织进行酶消化和不连续密度梯度离心以获得原代PSCs。采用免疫细胞化学染色检测PSCs中α-平滑肌肌动蛋白(SMA)、结蛋白(desmin)和纤维连接蛋白(FN)的表达;采用免疫细胞化学染色和原位杂交方法检测传代PSCs中TGF-β1和核心蛋白聚糖的蛋白和mRNA的表达。结果:体外成功分离并培养PSCs后,免疫细胞化学染色结果显示该细胞可活化,细胞质中出现α-SMA、desmin和FN阳性表达。在传代PSCs中,TGF-β1mRNA在细胞核和细胞质内均有表达,其蛋白则主要在细胞质内表达:核心蛋白聚糖则无论mRNA或蛋白均主要在细胞核内表达。结论:大鼠PSCs可成功地在体外分离并培养。在培养过程中,该细胞可自发活化并向成纤维样细胞分化。PSCs可自分泌TGF-β1和核心蛋白聚糖,并可能在基因转录水平进行自身调控,从而对胰腺纤维化的形成产生一定影响.

Background: Pancreatic stellate cells (PSCs) play an important role in the processes of pancreatic fibrosis. So it is necessary to study the cytokines that influence the activation of PSCs. Aims: To establish a mature method to separate and culture PSCs from rats, and to investigate the expression and distribution of transforming growth factor (TGF)-β1 and its antagonist, decorin, at transcription level (mRNA) and translation level (proteins) in passaged PSCs. Methods: Primary PSCs were obtained from pancreatic tissues in rats using the method of enzyme digestion and discontinuing density gradient centrifugation. Immunocytochemistry method was adopted to detect the expression of a-smooth muscle actin (SMA), desmin and fibronectin (FN) in PSCs. Immunocytochemistry and in situ hybridization methods were used to detect the expression of TGF-β1 and decorin's proteins and their mRNA in passaged PSCs. Results: PSCs were successfully separated and cultured in vitro. By means of im-munocytochemistry, the expression of a-SMA, desmin and FN could be detected in the cytoplasm of activated PSCs. The TGF-β1 mRNA was distributed at both nucleus and cytoplasm, while its protein was expressed mainly at cytoplasm; And both decorin mRNA and its protein were primarily located at nucleus within passaged PSCs. Conclusions: PSCs in rats can be successfully separated and cultured in vitro. With the process of cell culture, PSCs can be activated and differentiated into fibroblast by itself. PSCs also have the abilities to express TGF-β1 and decorin, and may take the responsibility in the formation of pancreatic fibrosis by self-regulating at the level of gene transcription.