Tryptophan photo-product FICZ upregulates AHR/MEK/ERK-mediated MMP1 expression: Implications in anti-fibrotic phototherapy

The amounts of extracellular matrix (ECM) components in the dermis, such as collagen, elastin, proteoglycan, and fibronectin, are regulated by control of the balance between two opposing processes: production and degradation. Transforming growth factor (TGF)-ß is a major profibrotic cytokine that transforms fibroblasts into myofibroblasts, which synthesize ECM proteins [1]. In scleroderma, fibroblasts that have been aberrantly activated through TGF-ß signaling may result in the production of abundant collagen [2].