Signaling of Prostaglandin E Receptors, EP3 and EP4 Facilitates Wound Healing and Lymphangiogenesis with Enhanced Recruitment of M2 Macrophages in Mice

PLoS One. 2016 Oct 6;11(10):e0162532. doi: 10.1371/journal.pone.0162532. eCollection 2016.

Abstract

Lymphangiogenesis plays an important role in homeostasis, metabolism, and immunity, and also occurs during wound-healing. Here, we examined the roles of prostaglandin E2 (PGE2) receptor (EP) signaling in enhancement of lymphangiogenesis in wound healing processes. The hole-punch was made in the ears of male C57BL/6 mice using a metal ear punch. Healing process and lymphangiogenesis together with macrophage recruitment were analyzed in EP knockout mice. Lymphangiogenesis was up-regulated in the granulation tissues at the margins of punched-hole wounds in mouse ears, and this increase was accompanied by increased expression levels of COX-2 and microsomal prostaglandin E synthase-1. Administration of celecoxib, a COX-2 inhibitor, suppressed lymphangiogenesis in the granulation tissues and reduced the induction of the pro-lymphangiogenic factors, vascular endothelial growth factor (VEGF) -C and VEGF-D. Topical applications of selective EP receptor agonists enhanced the expressions of lymphatic vessel endothelial hyaluronan receptor-1 and VEGF receptor-3. The wound-healing processes and recruitment of CD11b-positive macrophages, which produced VEGF-C and VEGF-D, were suppressed under COX-2 inhibition. Mice lacking either EP3 or EP4 exhibited reduced wound-healing, lymphangiogenesis and recruitment of M2 macrophages, compared with wild type mice. Proliferation of cultured human lymphatic endothelial cells was not detected under PGE2 stimulation. Lymphangiogenesis and recruitment of M2 macrophages that produced VEGF-C/D were suppressed in mice treated with a COX-2 inhibitor or lacking either EP3 or EP4 during wound healing. COX-2 and EP3/EP4 signaling may be novel targets to control lymphangiogenesis in vivo.

MeSH terms

  • Animals
  • CD11b Antigen / metabolism
  • Cyclooxygenase 2 / metabolism
  • Cyclooxygenase 2 Inhibitors / pharmacology
  • Ear / physiology
  • Gene Knockout Techniques
  • Lymphangiogenesis* / drug effects
  • Macrophages / cytology*
  • Macrophages / drug effects
  • Macrophages / immunology
  • Macrophages / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Prostaglandin-E Synthases / metabolism
  • Receptors, Prostaglandin E, EP3 Subtype / deficiency
  • Receptors, Prostaglandin E, EP3 Subtype / genetics
  • Receptors, Prostaglandin E, EP3 Subtype / metabolism*
  • Receptors, Prostaglandin E, EP4 Subtype / deficiency
  • Receptors, Prostaglandin E, EP4 Subtype / genetics
  • Receptors, Prostaglandin E, EP4 Subtype / metabolism*
  • Signal Transduction* / drug effects
  • Up-Regulation / drug effects
  • Vascular Endothelial Growth Factor C / biosynthesis
  • Vascular Endothelial Growth Factor D / biosynthesis
  • Wound Healing* / drug effects

Substances

  • CD11b Antigen
  • Cyclooxygenase 2 Inhibitors
  • Receptors, Prostaglandin E, EP3 Subtype
  • Receptors, Prostaglandin E, EP4 Subtype
  • Vascular Endothelial Growth Factor C
  • Vascular Endothelial Growth Factor D
  • Cyclooxygenase 2
  • Prostaglandin-E Synthases
  • Ptges protein, mouse

Grants and funding

This work was supported by the grants from The Ministry of Education, Culture, Sports, Science and Technology (MEXT), #15K08241, # 25860192, #15K15056, #26293055, #24659119, #23116102. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.