Abstract
Re-epithelialization begins early during skin wound healing and is regulated by various growth factors and cytokines. Angiotensin II promotes the migration of keratinocytes and thereby contributes to wound healing. We investigated the mechanism by which angiotensin II stimulates human keratinocyte migration. Angiotensin II–induced keratinocyte migration was inhibited by an angiotensin II type 1 receptor (AT1R) antagonist (candesartan) or an angiotensin II type 2 receptor (AT2R) antagonist (PD123319) as well as by depletion of AT1R or AT2R. A biased agonist for AT1R, [Sar1,Ile4,Ile8]angiotensin II, induced cell migration, whereas depletion of β-arrestin2 inhibited angiotensin II–induced migration. Angiotensin II–induced migration was blocked by neutralizing antibodies to transforming growth factor-β (TGF-β) as well as by the TGF-β receptor inhibitor SB431542. The amount of TGF-β1 was increased in the culture medium of angiotensin II–treated cells, and this effect was inhibited by candesartan or PD123319. Both angiotensin II– and TGF-β–induced cell migration were inhibited by neutralizing antibodies to the epidermal growth factor (EGF) receptor but not by those to EGF receptor ligands. Angiotensin II–induced phosphorylation of the EGF receptor, and this effect was inhibited by candesartan, PD123319, SB431542, or depletion of β-arrestin2, but not by neutralizing antibodies to heparin-binding EGF-like growth factor. Our results indicate that β-arrestin–dependent signaling downstream of AT1R as well as AT2R signaling are necessary for angiotensin II–induced keratinocyte migration, and that such signaling promotes generation of the active form of TGF-β, consequent activation of the TGF-β receptor, and transactivation of the EGF receptor by the TGF-β receptor.
Footnotes
- Received October 19, 2014.
- Accepted December 3, 2014.
↵1 Current affiliation: Faculty of Pharmaceutical Sciences, Himeji Dokkyo University, Himeji, Japan.
↵2 Current affiliation: Faculty of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto, Kumamoto, Japan.
↵3 Current affiliation: Ohshima Hospital of Ophthalmology, Fukuoka, Japan.
H.S. and K.M. contributed equally to this work.
This work was supported in part by a Grant-in-Aid for Challenging Exploratory Research from the Japan Society for the Promotion of Science [Grant #25670128], by a Yamaguchi University Research Project on Stress, and by a grant from Yamada Research Foundation.
↵This article has supplemental material available at molpharm.aspetjournals.org.
- Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics
MolPharm articles become freely available 12 months after publication, and remain freely available for 5 years.Non-open access articles that fall outside this five year window are available only to institutional subscribers and current ASPET members, or through the article purchase feature at the bottom of the page.
|