Taro Ishii1, Kunitoshi Uchida2, Shozaburo Hata1, Mitsutoki Hatta2, Tomo Kita2, Yuki Miyake1, Kazuhiko Okamura3, Sachio Tamaoki1, Hiroyuki Ishikawa1, Jun Yamazaki4. 1. Department of Oral Growth & Development, Fukuoka 814-0193, Japan. 2. Department of Physiological Science & Molecular Biology, Fukuoka 814-0193, Japan. 3. Department of Morphological Biology, Fukuoka Dental College, Fukuoka 814-0193, Japan. 4. Department of Physiological Science & Molecular Biology, Fukuoka 814-0193, Japan. Electronic address: junyama@college.fdcnet.ac.jp.
Abstract
BACKGROUND: Keratinocytes release several factors that are involved in wound contracture and scar formation. We previously reported that a three-dimensional reconstruction model derived from rat skin represents a good wound healing model. OBJECTIVE: We characterized the role of transient receptor potential (TRP) channels in the release of transforming growth factor (TGF)-β1 from keratinocytes and the differentiation of fibroblasts to identify possible promising pharmacological approaches to prevent scar formation and contractures. METHODS: The three-dimensional culture model was made from rat keratinocytes seeded on a collagen gel in which dermal fibroblasts had been embedded. RESULTS: Among the TRP channel inhibitors tested, the TRPV2 inhibitors SKF96365 and tranilast attenuated most potently keratinocyte-dependent and - independent collagen gel contraction due to TGF-β signaling as well as TGF-β1 release from keratinocytes and α-smooth muscle actin production in myofibroblasts. Besides the low amounts detected in normal dermis, TRPV2 mRNA and protein levels were increased after fibroblasts were embedded in the gel. TRPV2 was also expressed in the epidermis and keratinocyte layers of the model. Both inhibitors and TRPV2 siRNA attenuated the intracellular increase of Ca2+ induced by the TRPV agonist 2-aminoethoxydiphenyl borate in TGF-β1-pretreated fibroblasts. CONCLUSION: This is the first study to show that compounds targeting TRPV2 channels ameliorate wound contraction through the inhibition of TGF-β1 release and the differentiation of dermal fibroblasts in a culture model.
BACKGROUND: Keratinocytes release several factors that are involved in wound contracture and scar formation. We previously reported that a three-dimensional reconstruction model derived from rat skin represents a good wound healing model. OBJECTIVE: We characterized the role of transient receptor potential (TRP) channels in the release of transforming growth factor (TGF)-β1 from keratinocytes and the differentiation of fibroblasts to identify possible promising pharmacological approaches to prevent scar formation and contractures. METHODS: The three-dimensional culture model was made from rat keratinocytes seeded on a collagen gel in which dermal fibroblasts had been embedded. RESULTS: Among the TRP channel inhibitors tested, the TRPV2 inhibitors SKF96365 and tranilast attenuated most potently keratinocyte-dependent and - independent collagen gel contraction due to TGF-β signaling as well as TGF-β1 release from keratinocytes and α-smooth muscle actin production in myofibroblasts. Besides the low amounts detected in normal dermis, TRPV2 mRNA and protein levels were increased after fibroblasts were embedded in the gel. TRPV2 was also expressed in the epidermis and keratinocyte layers of the model. Both inhibitors and TRPV2 siRNA attenuated the intracellular increase of Ca2+ induced by the TRPV agonist 2-aminoethoxydiphenyl borate in TGF-β1-pretreated fibroblasts. CONCLUSION: This is the first study to show that compounds targeting TRPV2 channels ameliorate wound contraction through the inhibition of TGF-β1 release and the differentiation of dermal fibroblasts in a culture model.