Distinct biological events generated by ECM proteolysis by two homologous collagenases

Abstract

It is well established that the expression profiles of multiple and possibly redundant matrix-remodeling proteases (e.g., collagenases) differ strongly in health, disease, and development. Although enzymatic redundancy might be inferred from their close similarity in structure, their in vivo activity can lead to extremely diverse tissueremodeling outcomes. We observed that proteolysis of collagen-rich natural extracellular matrix (ECM), performed uniquely by individual homologous proteases, leads to distinct events that eventually affect overall ECM morphology, viscoelastic properties, and molecular composition. We revealed striking differences in the motility and signaling patterns, morphology, and gene-expression profiles of cells interacting with natural collagen-rich ECM degraded by different collagenases. Thus, in contrast to previous notions, matrix-remodeling systems are not redundant and give rise to precise ECM-cell crosstalk. Because ECM proteolysis is an abundant biochemical process that is critical for tissue homoeostasis, these results improve our fundamental understanding its complexity and its impact on cell behavior.T he function and integrity of the extracellular matrix (ECM) is vital for cell behavior as well as for whole-tissue homeostasis (1-4). The ECM undergoes constant remodeling during health and disease states. Its components are regularly being deposited, degraded, or otherwise modified. The highly stable fibrillar collagen type I (Col I) is abundant in many organ-derived ECMs and connective tissues (5, 6); it serves as a tissue scaffold, determining ECM mechanical properties and anchoring other ECM proteins necessary for cell function (7). These processes are orchestrated by multiple remodeling enzymes, among which the matrix metalloproteinase (MMP) family plays an important role. Only a few members of this proteinase family, the collagenases, are able to degrade the resistant fibrillar collagens, i.e., Col I, as well as other ECM molecules (8, 9). The collagenases have conserved amino acids in their zinc-containing catalytic domain (8, 10) and display high structural similarities, as reflected by their functional domain organization. Nevertheless, the complex effects exerted by different MMPs on ECM and cells in vivo remain poorly understood.The enzymatic activity of MMPs, and specifically of collagenases, in vivo is tightly regulated (11), with enzymatic dysregulation causing irreversible damage associated with a variety of diseases. Abnormally elevated levels of MMP-1 or of both MMP-1 and MMP-13 have been associated with different types of cancers and with inflammatory diseases (12-21).Here, we explored the degradation patterns of natural collagenrich ECM by two homologous MMPs and tested the response of cells to intact vs. selectively degraded ECM. We collectively profiled the unique remodeling events caused by two secreted collagenases, MMP-1 and MMP-13, by using biochemical, biophysical, and proteomics tools. We show that these proteases drive morphological, biochemical, and visc...

Matrix metalloproteinase collagenolysis in health and disease

“…MT1-MMP is also active intracellularly , processing centrosomal breast cancer type 2 susceptibility gene (BRCA2) and pericentrin, where the latter event leads to chromosomal instability [126, 127]. In addition, collagen hydrolysis by MMPs has other effects, such as directly disrupting the fibronectin binding site [128] and revealing cryptic binding sites within collagen chains [129–132]. Bulk collagenolysis may be performed by several MMPs in a redundant and compensatory fashion [78].…”

“…Bulk collagenolysis may be performed by several MMPs in a redundant and compensatory fashion [78]. However, the ultimate products of collagenolysis and their effects on cellular behaviors differ based on the specific MMP [132]. Precise roles for collagen catabolism have been ascertained from MMP knockout mice or mutant collagen mice.…”

Towards integrating extracellular matrix and immunological pathways

“…Another possibility, however, is that enzymes with structural homology are involved in distinct ECM remodeling pathways depending on the tissue and the nature of the insult. The latter hypothesis is supported by recent data demonstrating that two matrix proteases with structural homology and similar substrate specificity, MMP-1 and MMP-13, produce distinct ECM protein profiles that mediate different ECM-cell interactions (108). As we improve our knowledge of the regulation of ECM protein and remodeling enzyme expression in different tissues and disease states, we will gain a better understanding of the level of redundancy or specificity in ECM remodeling.…”

Scarring vs. functional healing: Matrix-based strategies to regulate tissue repair

“…Selective ECM degradation generates microenvironments with unique biochemical and morphological ECM properties to instruct cell behaviour [107]. Past studies have shown relative success in use of matrikines as inhibitors of angiogenesis and inflammation, and angiogenesis inhibitors have been proposed in clinical studies for cancer therapy [108, 109].…”