title: Polarized Secretion of Matrix Metalloproteinases and Their Inhibitors by Retinal Pigment Epithelium Derived from Induced Pluripotent Stem Cells During Wound Healing.
abstract: To characterize the secretion of matrix metalloproteinases (MMPs) and tissue inhibitors of matrix metalloproteinases (TIMPs) by induced pluripotent stem cell-derived retinal pigment epithelium (iPS-RPE) during wound healing. We hypothesize that iPS-RPE secretes mediators of tissue remodeling such as MMPs and TIMPs to promote migration and proliferation of cells during wound healing.
  
  
  
  iPS-RPE was grown on transwells until fully confluent and pigmented. The monolayers were scratched to induce a wound. Conditioned media were collected from the apical and basolateral sides of the transwells every 72 h for 12 days. The media were analyzed by multiplex ELISA assays to detect secreted MMPs and TIMPs. Activity assays were performed to detect the active form of MMP-2 in conditioned media.
  
  
  
  MMP-2 and TIMP-1, -2, -3, and -4 were detected in conditioned media from iPS-RPE. The proteins were found to be secreted in a polarized manner. The apical secretion and activation of MMP-2 was elevated from days 3 to 12 after wounding. TIMP-1, -2, -3, and -4 were detected in conditioned media from both the apical and basolateral sides of wounded cells. Apical secretion of all 4 TIMPs increased within 3 days after wounding.
  
  
  
  These results indicate that iPS-RPE secretes MMP-2 and all 4 TIMPs in a polarized manner. After wounding, apical secretion of MMP-2 was higher compared to control. Apical secretion of all 4 TIMPs increased compared to control, while only TIMP-1 showed increased basolateral secretion compared to control.
authors.affiliation: Ocular Trauma Task Area, U.S. Army Institute of Surgical Research , JBSA Fort Sam Houston, San Antonio, Texas.
authors.forename: Whitney A
authors.initials: WA
authors.lastname: Greene
authors.affiliation: Ocular Trauma Task Area, U.S. Army Institute of Surgical Research , JBSA Fort Sam Houston, San Antonio, Texas.
authors.forename: Teresa A
authors.initials: TA
authors.lastname: Burke
authors.affiliation: Ocular Trauma Task Area, U.S. Army Institute of Surgical Research , JBSA Fort Sam Houston, San Antonio, Texas.
authors.forename: Ramesh R
authors.initials: RR
authors.lastname: Kaini
authors.affiliation: Ocular Trauma Task Area, U.S. Army Institute of Surgical Research , JBSA Fort Sam Houston, San Antonio, Texas.
authors.forename: Elaine D
authors.initials: ED
authors.lastname: Por
authors.affiliation: Ocular Trauma Task Area, U.S. Army Institute of Surgical Research , JBSA Fort Sam Houston, San Antonio, Texas.
authors.forename: Heuy-Ching
authors.initials: HC
authors.lastname: Wang
mesh_terms: D002454:Cell Differentiation; D002478:Cells, Cultured; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D061965:Matrix Metalloproteinase Inhibitors / Q000494:pharmacology*; D020782:Matrix Metalloproteinases / Q000032:analysis / Q000378:metabolism*; D039904:Pluripotent Stem Cells / Q000187:drug effects*; D055213:Retinal Pigment Epithelium / Q000187:drug effects*; D014945:Wound Healing / Q000187:drug effects*
chemical_list: D061965:Matrix Metalloproteinase Inhibitors; D020782:Matrix Metalloproteinases
keywords: matrix metalloproteases; retinal pigment epithelium; wound healing