title: Cell wounding activates phospholipase D in primary mouse keratinocytes.
abstract: Plasma membrane disruptions occur in mechanically active tissues such as the epidermis and can lead to cell death if the damage remains unrepaired. Repair occurs through fusion of vesicle patches to the damaged membrane region. The enzyme phospholipase D (PLD) is involved in membrane traffickiing; therefore, the role of PLD in membrane repair was investigated. Generation of membrane disruptions by lifting epidermal keratinocytes from the substratum induced PLD activation, whereas removal of cells from the substratum via trypsinization had no effect. Pretreatment with 1,25-dihydroxyvitamin D₃, previously shown to increase PLD1 expression and activity, had no effect on, and a PLD2-selective (but not a PLD1-selective) inhibitor decreased, cell lifting-induced PLD activation, suggesting PLD2 as the isoform activated. PLD2 interacts functionally with the glycerol channel aquaporin-3 (AQP3) to produce phosphatidylglycerol (PG); however, wounding resulted in decreased PG production, suggesting a potential PG deficiency in wounded cells. Cell lifting-induced PLD activation was transient, consistent with a possible role in membrane repair, and PLD inhibitors inhibited membrane resealing upon laser injury. In an in vivo full-thickness mouse skin wound model, PG accelerated wound healing. These results suggest that PLD and the PLD2/AQP3 signaling module may be involved in membrane repair and wound healing.
authors.affiliation: Institute of Molecular Medicine and Genetics, Georgia Health Sciences University, Augusta, GA 30912.
authors.forename: Senthil N
authors.initials: SN
authors.lastname: Arun
authors.affiliation: Charlie Norwood VA Medical Center, Augusta, GA 30904.
authors.forename: Ding
authors.initials: D
authors.lastname: Xie
authors.affiliation: Department of Cell Biology and Anatomy, Georgia Health Sciences University, Augusta, GA 30912.
authors.forename: Amber C
authors.initials: AC
authors.lastname: Howard
authors.affiliation: Department of Physiology, Georgia Health Sciences University, Augusta, GA 30912.
authors.forename: Quincy
authors.initials: Q
authors.lastname: Zhong
authors.affiliation: Department of Physiology, Georgia Health Sciences University, Augusta, GA 30912.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Zhong
authors.affiliation: Department of Cell Biology and Anatomy, Georgia Health Sciences University, Augusta, GA 30912.
authors.forename: Paul L
authors.initials: PL
authors.lastname: McNeil
authors.affiliation: Charlie Norwood VA Medical Center, Augusta, GA 30904; Institute of Molecular Medicine and Genetics, Georgia Health Sciences University, Augusta, GA 30912; Department of Physiology, Georgia Health Sciences University, Augusta, GA 30912; Department of Cell Biology and Anatomy, Georgia Health Sciences University, Augusta, GA 30912.
authors.forename: Wendy B
authors.initials: WB
authors.lastname: Bollag
mesh_terms: D000818:Animals; D051400:Aquaporin 3 / Q000378:metabolism; D002117:Calcitriol / Q000494:pharmacology; D002478:Cells, Cultured; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D015603:Keratinocytes / Q000378:metabolism*; D008297:Male; D051379:Mice; D010715:Phosphatidylglycerols / Q000378:metabolism; D010739:Phospholipase D / Q000378:metabolism*; D014945:Wound Healing / Q000187:drug effects
chemical_list: D010715:Phosphatidylglycerols; D051400:Aquaporin 3; D010739:Phospholipase D; D002117:Calcitriol