title: Doxycycline inhibits matrix metalloproteinase-2 secretion from TSC2-null mouse embryonic fibroblasts and lymphangioleiomyomatosis cells.
abstract: OBJECTIVE
  Lymphangioleiomyomatosis (LAM) is characterized by the abnormal growth of smooth muscle-like cells (LAM cells) and cystic destruction of the lung parenchyma. LAM cell-derived matrix metalloproteinases (MMPs) are thought to play a prominent role in the tissue destruction. The aim of this study was to determine whether doxycycline, a known MMP inhibitor, can inhibit LAM cell proliferation or mitochondrial function and/or modulate MMPs and their tissue inhibitors (TIMPs).
  
  
  METHODS
  Wild-type and tuberous sclerosis complex-2 (TSC2)-null mouse embryonic fibroblasts (MEFs) were cultured in DMEM containing 10% fetal bovine serum (FBS). Human LAM cells were derived from the lungs of LAM patients and airway smooth muscle cells from control subjects. Cells were stimulated with FBS with or without doxycycline for up to 9 days. Proliferation was assessed by manual cell counts and MTT assay, MMP production by zymography and ELISA, and TIMP production using elisa.
  
  
  RESULTS
  Doxycycline did not change FBS-induced proliferation in MEFs or human cells. However, doxycycline did reduce metabolic activity of both wild-type and TSC2-null MEFs and LAM cells, but had no effect on control cells. Furthermore, doxycycline reduced MMP-2 from MEFs and decreased active-MMP-2 from LAM cells but had no effect on TIMP-1 and TIMP-2 from human LAM cells.
  
  
  CONCLUSIONS
  Doxycycline decreased MMP levels and cell metabolic activity, which raises the possibility of therapeutic efficacy in LAM.
authors.affiliation: Woolcock Institute of Medical Research, Sydney, NSW, Australia. lyn.moir@sydney.edu.au
authors.forename: L M
authors.initials: LM
authors.lastname: Moir
authors.forename: H Y
authors.initials: HY
authors.lastname: Ng
authors.forename: M H
authors.initials: MH
authors.lastname: Poniris
authors.forename: T
authors.initials: T
authors.lastname: Santa
authors.forename: J K
authors.initials: JK
authors.lastname: Burgess
authors.forename: B G G
authors.initials: BG
authors.lastname: Oliver
authors.forename: V P
authors.initials: VP
authors.lastname: Krymskaya
authors.forename: J L
authors.initials: JL
authors.lastname: Black
mesh_terms: D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D004318:Doxycycline / Q000494:pharmacology*; D005260:Female; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D006801:Humans; D018192:Lymphangioleiomyomatosis / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D020778:Matrix Metalloproteinase 2 / Q000096:biosynthesis / Q000378:metabolism; D061965:Matrix Metalloproteinase Inhibitors; D051379:Mice; D008875:Middle Aged; D008928:Mitochondria / Q000187:drug effects; D032389:Myocytes, Smooth Muscle / Q000378:metabolism; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000378:metabolism; D000077005:Tuberous Sclerosis Complex 2 Protein; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins / Q000172:deficiency* / Q000378:metabolism
chemical_list: D061965:Matrix Metalloproteinase Inhibitors; C000624653:TSC2 protein, human; D019715:Tissue Inhibitor of Metalloproteinase-1; C000624654:Tsc2 protein, mouse; D000077005:Tuberous Sclerosis Complex 2 Protein; D025521:Tumor Suppressor Proteins; D019716:Tissue Inhibitor of Metalloproteinase-2; D020778:Matrix Metalloproteinase 2; D004318:Doxycycline