title: Integrin α6β4 and TRPV1 channel coordinately regulate directional keratinocyte migration.
abstract: The directional migration of epithelial cells is crucial for wound healing. Among integrins, a family of cell adhesion receptors, integrin β4 has been assumed to be a promigratory factor, in addition to its role in stable adhesion. In turn, Ca(2+) signaling is also a key coordinator of migration. Keratinocytes reportedly express transient receptor potential vanilloid channels (TRPV1); however, the function of these channels as a regulator of intracellular Ca(2+) level in cell migration has remained uncharacterized. In the present study, we investigated the role of TRPV1 in directional migration related to integrin β4 using a scratch wound assay on a confluent monolayer sheet of murine keratinocytes (Pam212 cells). Double immunofluorescence staining revealed the de novo expression of integrin β4 and TRPV1 in migrating cells at the wound edge in response to scratch wounding, and both expression levels were almost matched. Epidermal growth factor (EGF) not only promoted keratinocyte migration, but also caused the further up-regulation of both integrin β4 and TRPV1. In addition, the knockdown of the integrin β4 or TRPV1 gene significantly impeded wound closure. The TRPV1 agonist capsaicin significantly promoted migration, while a selective TRPV1 antagonist inhibited it. The gene knockdown of TRPV1 inhibited the expression of the integrin β4 gene and that of β4 protein in migrating cells. These findings suggest that TRPV1 may stimulate directional migration directly by eliciting a Ca(2+) signal or indirectly via integrin β4 expression.
authors: Department of Oral Growth and Development, Fukuoka Dental College, 2-15-1 Tamura, Sawara-ku, Fukuoka 814-0193, Japan.
authors: Ayako
authors: A
authors: Miyazaki
authors: Department of Physiological Science and Molecular Biology, Fukuoka Dental College, 2-15-1 Tamura, Sawara-ku, Fukuoka 814-0193, Japan. Electronic address: ookut1@college.fdcnet.ac.jp.
authors: Tsuyako
authors: T
authors: Ohkubo
authors: Department of Physiological Science and Molecular Biology, Fukuoka Dental College, 2-15-1 Tamura, Sawara-ku, Fukuoka 814-0193, Japan.
authors: Mitsutoki
authors: M
authors: Hatta
authors: Department of Oral Growth and Development, Fukuoka Dental College, 2-15-1 Tamura, Sawara-ku, Fukuoka 814-0193, Japan.
authors: Hiroyuki
authors: H
authors: Ishikawa
authors: Department of Physiological Science and Molecular Biology, Fukuoka Dental College, 2-15-1 Tamura, Sawara-ku, Fukuoka 814-0193, Japan.
authors: Jun
authors: J
authors: Yamazaki
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D002211:Capsaicin / Q000494:pharmacology; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D003035:Cobalt / Q000378:metabolism; D004815:Epidermal Growth Factor / Q000378:metabolism / Q000494:pharmacology; D020868:Gene Silencing; D039161:Integrin alpha6beta4 / Q000235:genetics / Q000378:metabolism*; D015603:Keratinocytes / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D050916:TRPV Cation Channels / Q000235:genetics / Q000378:metabolism*; D015854:Up-Regulation; D014945:Wound Healing
chemical_list: D039161:Integrin alpha6beta4; D050916:TRPV Cation Channels; C493921:TRPV1 protein, mouse; D003035:Cobalt; D004815:Epidermal Growth Factor; D002211:Capsaicin; D002118:Calcium
keywords: Calcium signal; Cell migration; Integrin beta4; TRPV1 channels