The Expression of BMP-2m RNA in the Tissue of Experimental Ossification of Ligamentum Flavum and Its Significance

Objective:To study the mechanism of effection of BMP 2 in the course of ligamentum flavum ossification through gene analysis. Methods:Resect the tissue of ligamentum flavum of experimental segment in 2,4 and 6 weeks after implantation of rhBMP 2/gelform sponge composite (O group).Distract the total RNA from the pathological tissue. Detect the expression degree of BMP 2 mRNA using methods of Dot blot and Northern blot.Set up the impanting of PBS solution/gelform sponge composite as experimental control group(EC group). Animals without operation as negative control group (N group).pSBMP 2 plasmid as positive control group(P group).Results:Autoradiography of Dot blot and Northern blot showing that the expression of BMP 2 mRNA is the highest in the tissues resected from the animals 2 weeks after implanting of rhBMP 2. Then decrease gradually. The decreasing is obviously in 6 weeks. The changes of expression degree relate positively to the activity of chondrolization of fibroblast as shown in the study of pathology. There is no expression of BMP 2 mRNA in EC group and N group. The imaging dense scanning show that the values of expression degree of BMP 2 mRNA are 0.615±0.0184,0.443±0.0982 and 0.232±0.0749 seperatly in 2,4, and 6 weeks after implanting of rhBMP-2 Conclusions:There are different degrees of expression of BMP 2 mRNA in the tissues of ligamentum flavum during the ossification progression induced by rhBMP 2. The degree of expression relate positively to the activity of chondrolization of fibroblast. The internal BMP 2 may participate in the starting and continuing of ossification of ligamentum flavum.