**Question:** 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?

A. N-cadherins
B. Selectins
C. Integrins
D. Laminins

**Correct Answer:** C. Integrins

**Core Concept:** Integrins are a family of cell adhesion molecules (CAMs) that play a vital role in various biological processes, including tissue development, cell signaling, and wound healing. Integrins form heterodimers, consisting of an alpha and a beta subunit, which are non-covalently linked. They interact with extracellular matrix (ECM) proteins, such as fibronectin, collagen, and laminin, facilitating cell-cell and cell-matrix interactions. This interaction is essential for tissue organization, maintenance, and repair.

**Why the Correct Answer is Right:** Integrins are the principal component of the provisional matrix that forms during early wound healing, specifically alpha-actinin-4 and alpha-smooth muscle actin (alpha-SMA) integrins. These integrins are involved in the recruitment and activation of various cells, including fibroblasts, platelets, and macrophages, which are crucial for the early stages of wound healing. The provisional matrix, also known as the acute phase matrix, is a temporary extracellular matrix produced during the first few days of wound healing. It serves as a scaffold for the formation of the more permanent matrix (the granulation tissue matrix) and ultimately, the regenerated skin.

**Why Each Wrong Option is Incorrect:**

A. N-cadherins are transmembrane proteins involved in cell-cell adhesion, not cell-matrix adhesion, making them unsuitable for the role of the provisional matrix.

B. Selectins are a family of CAMs primarily involved in leukocyte adhesion and recruitment during inflammation, not in the formation of the provisional matrix during wound healing.

D. Laminins are a family of ECM proteins, not CAMs, and their primary function is to provide structural support to tissues, not facilitating cell-matrix adhesion.

**Clinical Pearl:** Understanding the role of integrins in wound healing is crucial for practicing physicians, as they contribute to tissue repair and remodeling. Knowledge of this allows for accurate diagnosis and appropriate management of wounds and burns, ensuring proper healing and minimizing complications such as scarring and infection.