title: Interaction of angiogenic microvessels with the extracellular matrix.
abstract: The extracellular matrix (ECM) plays a critical role in angiogenesis by providing biochemical and positional cues, as well as by mechanically influencing microvessel cell behavior. Considerable information is known concerning the biochemical cues relevant to angiogenesis, but less is known about the mechanical dynamics during active angiogenesis. The objective of this study was to characterize changes in the material properties of a simple angiogenic tissue before and during angiogenesis. During sprouting, there was an overall decrease in tissue stiffness followed by an increase during neovessel elongation. The fall in matrix stiffness coincided with peak matrix metalloproteinase mRNA expression and elevated proteolytic activity. An elevated expression of genes for ECM components and cell-ECM interaction molecules and a subsequent drop in proteolytic activity (although enzyme levels remained elevated) coincided with the subsequent stiffening. The results of this study show that the mechanical properties of a scaffold tissue may be actively modified during angiogenesis by the growing microvasculature.
authors.affiliation: Bioengineering Department, University of Utah, 50 South Central Campus Drive, Salt Lake City, UT 84112, USA.
authors.forename: Laxminarayanan
authors.initials: L
authors.lastname: Krishnan
authors.forename: James B
authors.initials: JB
authors.lastname: Hoying
authors.forename: Hoa
authors.initials: H
authors.lastname: Nguyen
authors.forename: Helen
authors.initials: H
authors.lastname: Song
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Weiss
mesh_terms: D000273:Adipose Tissue / Q000098:blood supply*; D000818:Animals; D049109:Cell Proliferation; D003094:Collagen / Q000378:metabolism; D004548:Elasticity; D042783:Endothelial Cells / Q000378:metabolism*; D004822:Epididymis; D005109:Extracellular Matrix / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism*; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism*; D005782:Gels; D015971:Gene Expression Regulation, Enzymologic; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D020782:Matrix Metalloproteinases / Q000235:genetics / Q000378:metabolism*; D008833:Microcirculation / Q000378:metabolism; D018919:Neovascularization, Physiologic; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D046509:Tissue Culture Techniques / Q000295:instrumentation
chemical_list: D016326:Extracellular Matrix Proteins; D005782:Gels; D012333:RNA, Messenger; D003094:Collagen; D020782:Matrix Metalloproteinases; D020780:Matrix Metalloproteinase 9