TGF-β_1调控组织工程瓣膜力学性能机制研究

Regulatory mechanism of transforming growth factor-beta 1 on mechanical properties of tissue engineered heart valve

目的:采用转化生长因子(TGF-β1)联合肌成纤维细胞构建组织工程心脏瓣膜(TEHV),探讨TGF-β1能否改善TEHV的力学性能及其可能机制。方法:分离培养大鼠肌成纤维细胞,细胞鉴定后种植于去细胞瓣叶支架上。将瓣叶置于含10ng/mlTGF-β1的培养液中,培养14d构建的TEHV做为实验组,对照组除培养液中不添加TGF-β1外,其余同实验组。检测两组TEHV的赖氨酰氧化酶(LOX)和羟脯氨酸含量,LOX和Ⅰ型胶原(COLL-1)mRNA表达,以及力学性能。结果:实验组TEHV的LOX和羟脯氨酸含量均高于对照组(P<0.05),LOX和COLL-1 mRNA表达均高于对照组(P<0.05),最大负荷、最大应力均高于对照组(P<0.05),而两组的最大应变和弹性模量的差异无统计学意义(P>0.05)。结论:在体外构建TEHV过程中,通过TGF-β1对肌成纤维细胞的调控作用,可以在基因水平增强细胞COLL-1和LOX mRNA的表达,使得胶原蛋白合成和交联程度增加,从而使TEHV的力学强度增加,力学性能得到改善。

Objective： To observe whether transforming growth factor-beta 1 （TGF-β1） can improve the mechanical properties of tissue engineered heart valve （TEHV） prepared by TGF-β1 and myofibroblasts. Methods： Myofibroblasts were isolated,cultured, identified, and seeded onto the decellularized aortic valve leaflet. In the experimental group, TEHV were cultured with DMEM containing 10 ng/ml TGF-β1 for 14 days. In the control group,TEHV were cultured with DMEM only for 14 days. The contents of lysyl oxidase （LOX） and hydroxyproline, the expression of LOX and COLL-1 mRNA, and the mechanical properties of the TEHVs were analyzed in each group. Results： The contents of LOX and hydroxyproline,expression of LOX and COLL-1 mRNA, Max-load, and Max-stress were significantly higher in the experimental group than those in the control group （all P〈0.05）. However,the experimental and control group showed comparable values of Max-strain and elastic modulus. Conclusion： TGF-β1 can increase expression of LOX and COLL-1 mRNA in the seeded ceils during TEHV construction,increasing the production and cross-linking of collagen,and improve the mechanical properties of the TEHV.