title: Video-rate bioluminescence imaging of matrix metalloproteinase-2 secreted from a migrating cell.
abstract: BACKGROUND
  Matrix metalloproteinase-2 (MMP-2) plays an important role in cancer progression and metastasis. MMP-2 is secreted as a pro-enzyme, which is activated by the membrane-bound proteins, and the polarized distribution of secretory and the membrane-associated MMP-2 has been investigated. However, the real-time visualizations of both MMP-2 secretion from the front edge of a migration cell and its distribution on the cell surface have not been reported.
  
  
  RESULTS
  The method of video-rate bioluminescence imaging was applied to visualize exocytosis of MMP-2 from a living cell using Gaussia luciferase (GLase) as a reporter. The luminescence signals of GLase were detected by a high speed electron-multiplying charge-coupled device camera (EM-CCD camera) with a time resolution within 500 ms per image. The fusion protein of MMP-2 to GLase was expressed in a HeLa cell and exocytosis of MMP-2 was detected in a few seconds along the leading edge of a migrating HeLa cell. The membrane-associated MMP-2 was observed at the specific sites on the bottom side of the cells, suggesting that the sites of MMP-2 secretion are different from that of MMP-2 binding.
  
  
  CONCLUSIONS
  We were the first to successfully demonstrate secretory dynamics of MMP-2 and the specific sites for polarized distribution of MMP-2 on the cell surface. The video-rate bioluminescence imaging using GLase is a useful method to investigate distribution and dynamics of secreted proteins on the whole surface of polarized cells in real time.
authors.affiliation: Department of Biochemistry, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan. tsuzuki@dpc.agu.ac.jp
authors.forename: Takahiro
authors.initials: T
authors.lastname: Suzuki
authors.forename: Chihiro
authors.initials: C
authors.lastname: Kondo
authors.forename: Takao
authors.initials: T
authors.lastname: Kanamori
authors.forename: Satoshi
authors.initials: S
authors.lastname: Inouye
mesh_terms: D002462:Cell Membrane / Q000378:metabolism; D002465:Cell Movement; D018450:Disease Progression; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D006367:HeLa Cells; D006801:Humans; D049449:Luminescence; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D008853:Microscopy / Q000379:methods; D008856:Microscopy, Fluorescence / Q000379:methods; D009362:Neoplasm Metastasis; D013997:Time Factors; D014741:Video Recording
chemical_list: D020778:Matrix Metalloproteinase 2