title: Disruption of tissue plasminogen activator gene reduces macrophage migration.
abstract: Tissue plasminogen activator (tPA) is an essential component of the proteolytic cascade that lyses blood clots. Various studies also suggest that tPA plays important roles in peripheral nerve regeneration. Here we show that disruption of tPA gene reduces macrophage migration after sciatic nerve injury in mice. Moreover, lack of tPA activity attenuates migrating ability of macrophages and affects MMP-9 expression and activity in macrophages in vitro. Addition of ethylenediaminetetraacetic acid (EDTA), which inhibits MMPs, abolished the differences of migration ability of macrophages between tPA(+/+) and tPA(-/-) mice. Axonal regeneration is correlated with the increase of macrophage migration, suggesting that tPA may help create a beneficial environment for axonal regeneration through promoting macrophage infiltration. This study shows that tPA may play a role in nerve regeneration through regulating the migration ability of macrophages. This function of tPA may depend on, at least in part, upregulating MMP-9 expression and activity in macrophages.
authors.affiliation: Department of Molecular Genetics and the Key Laboratory of Molecular Medicine, Ministry of Education, Fudan University, Shanghai 200032, PR China.
authors.forename: Changchun
authors.initials: C
authors.lastname: Ling
authors.forename: Tie
authors.initials: T
authors.lastname: Zou
authors.forename: Yao
authors.initials: Y
authors.lastname: Hsiao
authors.forename: Xianmei
authors.initials: X
authors.lastname: Tao
authors.forename: Zu-Lin
authors.initials: ZL
authors.lastname: Chen
authors.forename: Sidney
authors.initials: S
authors.lastname: Strickland
authors.forename: Houyan
authors.initials: H
authors.lastname: Song
mesh_terms: D000818:Animals; D002465:Cell Movement / Q000187:drug effects; D015536:Down-Regulation; D007962:Leukocytes / Q000166:cytology / Q000187:drug effects; D008264:Macrophages / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009186:Myelin Sheath / Q000378:metabolism; D009410:Nerve Degeneration / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D010959:Tissue Plasminogen Activator / Q000172:deficiency / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D010959:Tissue Plasminogen Activator; D020780:Matrix Metalloproteinase 9