Basement membrane degeneration is mediated by -

Extracellular Matrix (ECM) comprises of interstitial matrix and basement membrane. The degradation of collagen and other ECM proteins is achieved by a family of matrix metalloproteinases (MMPs) which are dependent on zinc ions for their activity. MMPs include interstitial collagenases, which cleave fibrillar collagen (MMP-1, -2 and -3) gelatinases (MMP-2 and 9), which degrade amorphous collagen and fibronectin stromelysins (MMP-3, -10, and -11), which degrade a variety of ECM constituents, including proteoglycans, laminin, fibronectin, and amorphous collagen. ref robbins pathology 9th ed page 105