Question

what role does the extracellular matrix play in the process of wound healing?

Answer 1

In our body, in tissues, cells are surrounded by a non cellular material mostly composed of collagens, proteoglycan, fibronectin, laminin and different glycoprotein known as extracellular matrix or ECM. The main function of ECM is to provide support to the cells and also participates in tissue repair, cell communicaiton and differentiation.

Wound healing is a cellular process where skin is able to repair its injury and ECM components are required for wound healing. Wound healing process by ECM is divided into four stages:

Hemostasis- when a tissue is injured, blood platelates stick to the place of injury and release chemical signal which is necessaey for clotting. This further activates ECM of fibrin and fibronectin which in turn form a meshwork so that platelets can bind to each other. Fibronectin further interact with other cells by integrin and fibroblast, keratinocytes and endothelial cells next migrarte to the site of injury.

Inflammaion- in this stage leukocytes from circulation binds to ECM proteins. ECM proteins next activates monocytes or macrophages to clear the debris from injury site. Additonally monocytes also differentiate to macrophages and produce different cytokines and chemoattractant.

Proliferation-in this stage granulation tissue develops and wound start to contract. Macrophage binds to ECM and release growth factors to stimulate angiogenesis, synthesis of collagen and proliferation of fibroblasts.

Remodelling- in this stage fibroblasts interact with ECM proteins and growth factor and converted to myofibroblasts. Myofibroblasts further helps to contract the wound combining with different proteins like vitronectin, collagen. During this process collagen bundles replace collagen fiber and hyaluronic acid to strngthen the tissue.