ABSTRACT
Keloids represent a pathological response to cutaneous injury creating disfiguring scars with no known satisfactory treatment. They are unique to humans and are characterized by an overabundant extracellular matrix (ECM) deposition, especially collagen (1). Clinically, the lesions characteristically extend beyond the boundaries of the original wound and are seen predominantly in darkerpigmented individuals, including African-Americans, Hispanics, and Asians (2). Keloids are benign skin ‘‘tumors’’ that can be caused by even minor skin injury, such as ear piercing. In general, excessive or pathological scar formation after trauma or surgery can have devastating consequences, such as body disfigurement and organ dysfunction. The exact pathogenic mechanisms underlying keloids continue to be elusive, though much of the research focus has recently been aimed at the biomolecular pathways responsible for excessive ECM accumulation. In this review, we discuss previous keloid research as well as focus attention on more recent progress made in the understanding of molecular mechanisms of keloid formation. These recent studies are aimed at providing a basis for the development of more effective keloid treatments.
