First Author | Mishima T | Year | 2017 |
Journal | J Surg Res | Volume | 219 |
Pages | 50-60 | PubMed ID | 29078910 |
Mgi Jnum | J:273920 | Mgi Id | MGI:6282853 |
Doi | 10.1016/j.jss.2017.05.124 | Citation | Mishima T, et al. (2017) RAMP1 signaling improves lymphedema and promotes lymphangiogenesis in mice. J Surg Res 219:50-60 |
abstractText | BACKGROUND: Secondary lymphedema commonly arises as a complication of cancer surgery and radiation treatment; however, the underlying mechanisms are poorly understood. Receptor activity-modifying protein 1 (RAMP1) forms a complex with calcitonin receptor-like receptor to generate the receptor for calcitonin gene-related peptide. The present study examined whether RAMP1 plays a role in increased lymphangiogenesis during secondary lymphedema. METHODS: A model of lymphedema was generated by surgical removal of pre-existing lymphatic vessels from the subcutaneous tissue on the tails of RAMP1-deficient (RAMP1-/-) mice and their wild-type (WT) counterparts. The maximum diameter of the tail, lymphangiogenesis, and macrophage recruitment were then examined. RESULTS: Compared with that in WT mice, lymphedema in the tails in RAMP1-/- mice was sustained, with suppressed lymphangiogenesis and reduced expression of vascular endothelial growth factor-C and vascular endothelial growth factor receptor 3 at the distal edge of the lesions. The newly formed lymphatic vessels in RAMP1-/- mice were dilated, with impaired lymphatic flow. RAMP1 was expressed by macrophages recruited into edematous tail tissues distal to the wound. The number of macrophages in RAMP1-/- mice was higher than that in WT mice. Expression of messenger RNA encoding M1 macrophage-related genes, including tumor necrosis factor-alpha and interleukin-1, was higher in RAMP1-/- mice than in WT mice, whereas expression of messenger RNA encoding M2 macrophage genes, including interleukin-10, was lower. CONCLUSIONS: RAMP1 signaling improves lymphedema and accelerates lymphangiogenesis associated with reduced recruitment of pro-inflammatory macrophages. |