The formation of the microvasculature is a complex process requiring proper cell-cell and cell-extracellular matrix (ECM) communication events. A vascular basement membrane rich in many ECM proteins surrounds all blood vessels and regulates multiple vascular cell functions. Endothelial cells and pericytes, and indeed most eukaryotic cells, recognize ECM ligands primarily via members of the integrin family of proteins . Integrins are heterodimeric cell surface receptors consisting of noncovalently associated a and b subunits. Most integrins recognize multiple ECM ligands, and many ECM proteins can bind to more than one integrin receptor. In vertebrates there are 26 integrin genes, 18 encoding a subunits and 8 encoding b subunits, yielding 24 distinct integrin heterodimers (Figure 1). At least five integrins (albl, a2b1, a5b1, avb3, and avb5) are expressed at some point on endothelial cells or pericytes . Here we summarize pertinent data linking integrins and their ECM ligands to various microvascular events.
Was this article helpful?
This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.