Fibroblasts from the transversalis fascia of young patients with direct inguinal hernias show constitutive MMP-2 overexpression

Objective To determine the expression pattern of certain metalloproteinases (MMPs) known to be involved in the degradation of the extracellular matrix in cultured fibroblasts from the transversalis fascia (TF) of patients wit h inguinal hernia. Summary Background Data Inguinal hernia is a common pathology, the cause of which remains unknown. It is, however, clear that the TF is one of the ana tomical structures that may impede the formation of hernias, and particular ly the direct type of hernia. In previous studies the authors found enhance d MMP-2 expression in TF specimens in vivo. The persistence of increased ex pression in cultured fibroblasts might support the idea of a genetic defect as the cause for this pathology. Methods Fibroblasts from the TF of patients with direct and indirect inguin al hernia were cultured and compared with those obtained from control TF in terms of MMP (MMP-2 and MMP-9) expression. Results Significant active MMP-2 expression was shown by TF fibroblasts fro m young patients with direct hernias. These findings were confirmed by immu nosorbent assay, immunoblotting, and zymography of the fibroblast culture m edia. No MMP-9 expression was detected. Conclusion These results indicate that MMP-2 may be involved in the TF matr ix degradative process in patients with direct hernia, The persistence of c hanges in MMP-2 levels in the cell cultures appears to suggest a genetic de fect or irreversible change as the origin of this pathology rather than env ironmental factors, which may later participate in the development of the h ernial process.