BIOCHEMICAL FEATURES, PATHOPHYSIOLOGY AND MEDICALSIGNIFICANCE OF MATRIX METALLOPROTEINASE-9 (MMP-9): A REVIEW ARTICLE

Matrix metalloproteinase (MMP)-9 (also known as gelatinase B) is a member of the MMP family of endopeptidases (zinc-dependent) that has been connected with tumor cell invasion and metastasis and tumor-induced angiogenesis, through its ability to remodel the extracellular matrix. Under physiological conditions, MMP-9 provides tissue homeostasis by controlling matrices degradation involved in different types of physiological processes such as wound healing process, angiogenesis, immune cell migration and regulation of tissue repair activity. On the contrary, deregulated expression and excessive activation of MMP-9 have been implicated in the pathogenesis of many diseases such as chronic inflammatory disorders, cardiovascular diseases, neurodegenerative disease. fibroses and cancers. MMP-9 is implicated in leukocyte infiltration and activation of inflammatory cytokines, disruption of basement membrane integrity, and increased pathological tissue remodeling. In oncology, up-regulation of MMP-9 expression is closely relatedto the tumor invasion/metastasis/angiogenesis and poor clinical prognosis which makes it an attractive diagnostic and therapeutic target. In a similar manner, elevated MMP-9 activity has been associated with the exacerbation of rheumatoid arthritis, inflammatory bowel disease, chronic obstructive pulmonary disease, diabetic complications and neurological disorders involving continuous degradation of the extracellular matrix and persistent inflammation. In addition to its pathological roles, MMP-9 has emerged as a potential biomarker for disease diagnosis, prognosis and monitoring of therapeutic responses because of its close association with severity/extentofpathological processesand tissue remodeling.