Related Experiment Video
Updated: Jun 19, 2026

Evaluation of Keratinocyte Proliferation on Two- and Three-dimensional Type I Collagen Substrates
Published on: April 22, 2019
IL-18 downregulates collagen production in human dermal fibroblasts via the ERK pathway
Hee Jung Kim1, Seok Bean Song, Jung Min Choi
1Department of Dermatology, St Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Abstract:
Excessive accumulation of collagen contributes to the fibrotic process. Several experimental studies have shown that IFN-gamma is effective in preventing fibrogenesis. IL-18, originally identified as an IFN-gamma-inducing factor, is a key mediator of inflammation and host defense responses. In this study, we investigated the regulatory effect of IL-18 on the expression of type I and III collagen genes in dermal fibroblasts. The exposure of human dermal fibroblasts (HDFs) to IL-18 resulted in a reduction of collagen gene expression and production. Also, IL-18 inhibited the fibrogenic cytokine transforming growth factor (TGF)-beta-induced collagen gene expression. Next, to determine the molecular mechanism involved in this regulation, we showed that IL-18-regulated collagen expression was blocked by small interfering RNA (siRNA)-mediated Ets-1 knockdown. Furthermore, we showed that IL-18 induced phosphorylation of extracellular signal-regulated kinase (ERK) within 10 minutes and that the ERK inhibitor PD98059 blocked the inhibitory effect of IL-18. IL-18 also inhibited the production of collagen in systemic sclerosis (SSc) dermal fibroblasts. Our data indicate that IL-18 downregulates collagen production in HDF directly via Ets-1 and the ERK pathway, suggesting that IL-18 may exert antifibrotic activities in dermal fibroblasts.
Related Concept Videos
Fibril-associated Collagen
For example, the type II collagen fibrils in cartilage have covalently bound type IX fibril-associated collagens at regular intervals. Other types of fibril-associated collagens are...
TGF - β Signaling Pathway
Structural Protein Function
Collagen, the most abundant protein in mammals, is found throughout the body. In connective tissue, such as skin, ligaments, and tendons, it provides tensile strength and elasticity. In bones and teeth, it mineralizes to form...
Renewal of Skin Epidermal Stem Cells
Phases of Wound Repair
Formation of Blood Clot
In case of deep injuries, trauma to blood vessels results in blood loss. In the meantime, phospholipids released from the ruptured endothelial cellular membrane are converted into arachidonic...
The JAK-STAT Signaling Pathway
