12-Hydroxyheptadecatrienoic acid promotes epidermal wound healing by accelerating keratinocyte migration via the BLT2 receptor.
Bottom Line: Leukotriene B4 (LTB4) receptor type 2 (BLT2) is a G protein-coupled receptor (GPCR) for 12(S)-hydroxyheptadeca-5Z,8E,10E-trienoic acid (12-HHT) and LTB4.Despite the well-defined proinflammatory roles of BLT1, the in vivo functions of BLT2 remain elusive.These results identify a novel mechanism underlying the action of the 12-HHT/BLT2 axis in epidermal keratinocytes and accordingly suggest the use of BLT2 agonists as therapeutic agents to accelerate wound healing, particularly for intractable wounds, such as diabetic ulcers.
Affiliation: Department of Biochemistry, Juntendo University School of Medicine, Tokyo 113-8421, Japan Department of Medical Biochemistry, Kyushu University, Fukuoka 812-8582, Japan.Show MeSH
Related in: MedlinePlus
License 1 - License 2
Mentions: To analyze the detailed mechanisms behind the participation of the 12-HHT/BLT2 axis in cell migration, we next examined the effect of BLT2 overexpression on the migration of HaCaT cells (a human keratinocyte cell line) that do not endogenously express functional BLT2. Stable overexpression of BLT2 was confirmed by flow cytometry (Fig. 6 A), and BLT2 overexpression had no effect on cell proliferation (Fig. 6 B). Either BLT2 overexpression or 12-HHT treatment did not promote resistance to cell death both in HaCaT-mock and HaCaT-BLT2 cells during scratch assay (Fig. 6 C). In contrast, HaCaT-BLT2 cells migrated faster than HaCaT-mock cells in the presence of 0.5% FCS that contains ∼0.75 nM 12-HHT (Kita et al., 2005; Matsunobu et al., 2013; Fig. 6, D and E; Videos 3 and 4). Moreover, the BLT2 antagonist LY255283 (Yokomizo et al., 2001) inhibited the migration of HaCaT-BLT2 cells, but not HaCaT-mock cells (Fig. 6 F). Conversely, both 12-HHT and a BLT2 agonist accelerated the migration of HaCaT-BLT2 cells in the absence of FCS but had no effect on HaCaT-mock cells (Fig. 6, G and H). Furthermore, mitomycin C treatment, which inhibits cell proliferation, did not alter BLT2-dependent cell migration (unpublished data). Thus, the 12-HHT/BLT2 axis accelerates keratinocyte migration in vitro independently of cell proliferation and cell death.
Affiliation: Department of Biochemistry, Juntendo University School of Medicine, Tokyo 113-8421, Japan Department of Medical Biochemistry, Kyushu University, Fukuoka 812-8582, Japan.