The interaction of ceramide 1-phosphate with group IVA cytosolic phospholipase A 2 coordinates acute wound healing and repair

• Published in: Science signaling 2019-12, Vol.12 (610)
• Main Authors: MacKnight, H Patrick, Stephenson, Daniel J, Hoeferlin, L Alexis, Benusa, Savannah D, DeLigio, James T, Maus, Kenneth D, Ali, Anika N, Wayne, Jennifer S, Park, Margaret A, Hinchcliffe, Edward H, Brown, Rhoderick E, Ryan, John J, Diegelmann, Robert F, Chalfant, Charles E
• Format: Article
• Language: English
• Subjects: Animals; Cell Movement; Cell Nucleus - metabolism; Cell Proliferation; Ceramides - metabolism; Collagen - metabolism; Cytoplasm - metabolism; Cytosol - metabolism; Dinoprostone - metabolism; Eicosanoids - metabolism; Fibroblasts - metabolism; Genotype; Group IV Phospholipases A2 - genetics; Group IV Phospholipases A2 - metabolism; Hydroxyeicosatetraenoic Acids - pharmacology; Inflammation; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Microscopy, Fluorescence; Phenotype; Skin - metabolism; Tensile Strength; Thromboxane B2 - metabolism; Wound Healing
• ISSN: 1945-0877; 1937-9145
• DOI: 10.1126/scisignal.aav5918

The sphingolipid ceramide 1-phosphate (C1P) directly binds to and activates group IVA cytosolic phospholipase A (cPLA α) to stimulate the production of eicosanoids. Because eicosanoids are important in wound healing, we examined the repair of skin wounds in knockout (KO) mice lacking cPLA α and in knock-in (KI) mice in which endogenous cPLA α was replaced with a mutant form having an ablated C1P interaction site. Wound closure rate was not affected in the KO or KI mice, but wound maturation was enhanced in the KI mice compared to that in wild-type controls. Wounds in KI mice displayed increased infiltration of dermal fibroblasts into the wound environment, increased wound tensile strength, and a higher ratio of type I:type III collagen. In vitro, primary dermal fibroblasts (pDFs) from KI mice showed substantially increased collagen deposition and migration velocity compared to pDFs from wild-type and KO mice. KI mice also showed an altered eicosanoid profile of reduced proinflammatory prostaglandins (PGE and TXB ) and an increased abundance of certain hydroxyeicosatetraenoic acid (HETE) species. Specifically, an increase in 5-HETE enhanced dermal fibroblast migration and collagen deposition. This gain-of-function role for the mutant cPLA α was also linked to the relocalization of cPLA α and 5-HETE biosynthetic enzymes to the cytoplasm and cytoplasmic vesicles. These findings demonstrate the regulation of key wound-healing mechanisms in vivo by a defined protein-lipid interaction and provide insights into the roles that cPLA α and eicosanoids play in orchestrating wound repair.