title: Functions of rhomboid family protease RHBDL2 and thrombomodulin in wound healing.
abstract: The expression of thrombomodulin (TM), a membrane glycoprotein, is upregulated in neoepidermis during cutaneous wound healing. Rhomboid-like-2 (RHBDL2), an intramembrane serine protease, specifically cleaves TM at the transmembrane domain and causes the release of soluble TM (sTM). However, the physiological functions of TM and RHBDL2 in wound healing remain unclear. We demonstrated that both TM and RHBDL2 are upregulated in HaCaT cells stimulated by scratch wounds; furthermore, increased sTM was found in culture medium. Conversely, inhibition of RHBDL2 by 3,4-dichloroisocoumarin (DCI) or short hairpin RNA significantly inhibited wound-induced TM ectodomain shedding and wound healing. Both conditioned media from multiple-scratch-wounded HaCaT and recombinant sTM accelerated wound healing in HaCaT cells; such effects were abrogated by anti-TM antibodies. The RNA released from injured cells is involved in the induction of TM and RHBDL2. RHBDL2 and sTM were upregulated in ex vivo tissue culture of the injured skin. Furthermore, DCI inhibited sTM production and wound healing; this was reversed by recombinant sTM in mice. Thus, RHBDL2 and TM have important roles in wound healing via the release of sTM from keratinocytes; this may function as an autocrine/paracrine signal promoting wound healing.
authors.affiliation: Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan, Taiwan, ROC.
authors.forename: Tsung-Lin
authors.initials: TL
authors.lastname: Cheng
authors.forename: Yu-Ting
authors.initials: YT
authors.lastname: Wu
authors.forename: Hung-Yu
authors.initials: HY
authors.lastname: Lin
authors.forename: Fu-Chih
authors.initials: FC
authors.lastname: Hsu
authors.forename: Shi-Kai
authors.initials: SK
authors.lastname: Liu
authors.forename: Bi-Ing
authors.initials: BI
authors.lastname: Chang
authors.forename: Wei-Sheng
authors.initials: WS
authors.lastname: Chen
authors.forename: Chao-Han
authors.initials: CH
authors.lastname: Lai
authors.forename: Guey-Yueh
authors.initials: GY
authors.lastname: Shi
authors.forename: Hua-Lin
authors.initials: HL
authors.lastname: Wu
mesh_terms: D000818:Animals; D019138:Antibodies, Blocking / Q000494:pharmacology; D002460:Cell Line; D003374:Coumarins / Q000494:pharmacology; D017077:Culture Media, Conditioned / Q000378:metabolism / Q000494:pharmacology; D010450:Endopeptidases / Q000378:metabolism*; D006801:Humans; D049934:Isocoumarins; D015603:Keratinocytes / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D034741:RNA, Small Interfering / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology; D012697:Serine Endopeptidases; D057057:Serine Proteases / Q000187:drug effects / Q000378:metabolism*; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology; D012867:Skin / Q000378:metabolism; D018180:Thrombomodulin / Q000037:antagonists & inhibitors / Q000378:metabolism*; D014945:Wound Healing
chemical_list: D019138:Antibodies, Blocking; D003374:Coumarins; D017077:Culture Media, Conditioned; D049934:Isocoumarins; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; D015842:Serine Proteinase Inhibitors; C546931:THBD protein, human; C569169:THBD protein, mouse; D018180:Thrombomodulin; C046235:3,4-dichloroisocoumarin; D010450:Endopeptidases; D057057:Serine Proteases; C483398:RHBDL2 protein, mouse; D012697:Serine Endopeptidases; C545655:RHBDL2 protein, human