A 34-year-old woman has a benign nevus removed from her back under local anesthesia. Which of the following families of cell adhesion molecules is the principal component of the "provisional matrix" that forms during early wound healing?

Fibronectins. Fibronectins are adhesive glycoproteins that are widely distributed in stromal connective tissue and deposited at the site of tissue injury. During the initial phase of healing, fibronectin in the extravasated plasma is cross-linked to fibrin, collagen, and other extracellular matrix components by the action of transglutaminases. This cross-linking provides a provisional stabilization of the wound during the first several hours. Fibronectin, cell debris, and bacterial products are chemoattractants for a variety of cells that are recruited to the wound site over the next several days. Selectins (choice E) are sugar-binding glycoproteins that mediate the initial adhesion of leukocytes to endothelial cells at sites of inflammation. They are found at the cell surface and are not part of the extracellular matrix. Cadherins (choice A) and integrins (choice C) are cell adhesion molecules. Like the selectin family of cell adhesion proteins, they are found at the cell surface and are not part of the extracellular matrix.Diagnosis: Wound healing