Gingival fibroblast inhibits MMP-7: Evaluation in an ex vivo aorta model

Matrix metalloproteinases (MMP) play a deleterious role in numerous vascular diseases. In contrast, gingival matrix remodelling is adequately regulated by the gingival fibroblast (GF). Here, we aimed to evaluate the GF activity on MMP-7 expression and secretion in coculture with aorta rings. We evaluated MMP-7 transcription and secretion in rabbit aorta rings cultured or not with gingival fibroblasts in collagen gels. GF induced an increase of TIMP-1 transcription and secretion, followed, similarly to other MMPs, by the formation of TIMP-1/MMP-7 complexes. There was also a decrease of MMP-7 mRNA by RT-PCR in aorta rings cocultured with gingival fibroblasts. Interestingly, in contrast with other MMPs (which were not influenced at a transcription level), GF stimulated the release of TGF-β1, which in turn inhibited the transcription and synthesis of MMP-7, as shown by neutralizing MMP-7 inhibition due to gingival fibroblast by overexpressing decorin (a TGFβ1 inhibitor) or by silencing TGFβ1 using siRNA. We showed that healing properties of the GF could be transposed to another organ, i.e., ex vivo aneurism model, implicating a down-regulation of MMP-7.