The cutaneous basement membrane is a specialized extracellular matrix (ECM) that separates the epidermis from the dermis. During skin development and wound repair, the basement membrane undergoes extensive changes in structure and composition that are associated with changes in cell migration, signal transduction, and gene expression. Integrin alpha3beta1 is an adhesion receptor on epidermal keratinocytes that binds laminin-5 in the basement membrane. Mutation of the alpha3 gene in mouse revealed a critical role for alpha3beta1 in organization of the basement membrane in developing skin. Cell invasive processes such as skin development, wound healing, and carcinoma invasion are facilitated by proteolysis of the pericellular ECM, in which integrins contribute to functional regulation of matrix metalloproteinases (MMPs) or other ECM-degrading proteinases. Alpha3beta1 may have such a role during wound repair, where its high expression on keratinocytes coincides with the activation of ECM-degrading enzymes. However, mechanisms whereby alpha3beta1 controls ECM remodeling in skin development and wound healing are unknown. The proposed research exploits alpha3beta1-deficient mice, and keratinocyte cell lines derived from them, as a unique model system for defining these mechanisms. Preliminary data for these studies show that alpha3beta1 is required in keratinocytes for distinct proteinase function and for expression of genes encoding known ECM proteinases or proteinase inhibitors. Biochemical and molecular methods, with skin and cultured keratinocytes from normal or alpha3beta1-deficient mice, will be used to identify proteinases that are regulated by alpha3beta1. Candidate proteinases will them be tested directly for their abilities to restore alpha3beta1-dependend functions through transfection of alpha3beta1-deficient keratinocytes. To define integrin-mediated signaling pathways that regulate ECM remodeling, signaling proteins that are activated in an alpha3beta1-dependent manner will be identified using immunobiochemical methods. Dominant-negative mutants of these proteins will then be transfected into alpha3beta1-expressing keratinocytes and tested for inhibition of endogenous proteinase activity or expression. This research will provide important insights into the roles of integrins in regulating ECM remodeling at the levels of gene expression and proteinase function, and may contribute to the development of therapeutic approaches to control wound healing or carcinoma invasion.

National Institute of Health (NIH)
National Cancer Institute (NCI)
Research Project (R01)
Project #
Application #
Study Section
Pathobiochemistry Study Section (PBC)
Program Officer
Moshell, Alan N
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Albany Medical College
Schools of Medicine
United States
Zip Code
Mitchell, Kara; Szekeres, Charles; Milano, Vincenzo et al. (2009) Alpha3beta1 integrin in epidermis promotes wound angiogenesis and keratinocyte-to-endothelial-cell crosstalk through the induction of MRP3. J Cell Sci 122:1778-87
Lamar, John M; Pumiglia, Kevin M; DiPersio, C Michael (2008) An immortalization-dependent switch in integrin function up-regulates MMP-9 to enhance tumor cell invasion. Cancer Res 68:7371-9
Lamar, John M; Iyer, Vandana; DiPersio, C Michael (2008) Integrin alpha3beta1 potentiates TGFbeta-mediated induction of MMP-9 in immortalized keratinocytes. J Invest Dermatol 128:575-86
Choma, David P; Milano, Vincenzo; Pumiglia, Kevin M et al. (2007) Integrin alpha3beta1-dependent activation of FAK/Src regulates Rac1-mediated keratinocyte polarization on laminin-5. J Invest Dermatol 127:31-40
Iyer, Vandana; Pumiglia, Kevin; DiPersio, C Michael (2005) Alpha3beta1 integrin regulates MMP-9 mRNA stability in immortalized keratinocytes: a novel mechanism of integrin-mediated MMP gene expression. J Cell Sci 118:1185-95
Choma, David P; Pumiglia, Kevin; DiPersio, C Michael (2004) Integrin alpha3beta1 directs the stabilization of a polarized lamellipodium in epithelial cells through activation of Rac1. J Cell Sci 117:3947-59
Manohar, Asha; Shome, Swati Ghosh; Lamar, John et al. (2004) Alpha 3 beta 1 integrin promotes keratinocyte cell survival through activation of a MEK/ERK signaling pathway. J Cell Sci 117:4043-54
DiPersio, C M; Shao, M; Di Costanzo, L et al. (2000) Mouse keratinocytes immortalized with large T antigen acquire alpha3beta1 integrin-dependent secretion of MMP-9/gelatinase B. J Cell Sci 113 ( Pt 16):2909-21