EXTRACELLULAR MATRIX REMODELING IN EXPERIMENTAL INTERVERTEBRAL DISC DEGENERATION

Objective: To evaluate the remodeling of the extracellular matrix in intervertebral disc degeneration through the experimental model of intervertebral disc degeneration. Methods: The model of disc degeneration induction, using needle 20G and 360 degrees rotation, was applied for 30 seconds between the 6th/7th, and 8th/9th coccygeal vertebrae of Wistar rats. The intermediary level, between the 7th and 8th vertebrae, was taken as control, not being subjected puncture. The distribution of the extracellular matrix components involved in the remodeling and inflammation process, such as proteoglycans (aggrecan, decorin, biglycan), growth factors (TGF beta), heparanase isoforms (HPSE1, HPSE2), metaloprotesasis-9 (MMP9) and interleukins (IL-6, IL-10) was analyzed during the post-injury period (15 to 30 days) and in the control group (discs collected immediately after the puncture, day zero). On the 15th day, acute phase of the disease, a reduced expression of extracellular matrix components had been observed, whilst there were no differences in the interleukins expression. At 30 days, the molecules followed a very similar pattern of expression in the control group (not affected by disc degeneration). Results: The results show that during the acute phase significant alterations in the extracellular matrix components occur and in the late phase intervertebral disc returns to a profile similar to noninvolved tissue, probably due to extensive remodeling process of the extracellular matrix that is capable of regenerating the damaged tissue. Conclusion: The experimental model used demonstrated the occurrence of significant changes in the extracellular matrix during the period analyzed after induction of intervertebral disc degeneration. Laboratory investigation.