title: Autocrine actions of matrix metalloproteinase (MMP)-2 counter the effects of MMP-9 to promote survival and prevent terminal differentiation of cultured human keratinocytes.
abstract: Cultured human keratinocytes produce matrix metalloproteinase (MMP)-2 and MMP-9. In this study, using small interfering RNA (siRNA) for MMP-2 or MMP-9, we investigated the functions of these two gelatinases in the regulation of survival by measuring growth, differentiation, apoptosis, and migration of cultured keratinocytes. MMP-2 siRNA treatment significantly decreased keratinocyte growth and migration, and stimulated apoptosis fourfold. In addition, MMP-2 siRNA caused a 70% reduction in keratin-14 (K14) and a fourfold increase in K10. In contrast, MMP-9 siRNA treatment exerted opposite effects on cell growth, apoptosis, and K10 expression. MMP-2 appears to act through the ERK MAP kinase and caspase-3 signaling pathways as evidenced by the 53% reduction in the level of phosphorylated ERK1/2 and threefold increase in phosphorylated p38 and stronger staining for active caspase-3 in response to MMP-2 siRNA. Dual fluorescent staining revealed that almost all cultured cells stained positive for MMP-2, with only a few scattered cells being positive for MMP-9. There were considerably more BrdU-positive cells following MMP-9 siRNA treatment, indicating that MMP-9 inhibited proliferation. In conclusion, MMP-2 stimulates keratinocyte survival whereas MMP-9 promotes terminal differentiation.
authors.affiliation: Sutton Arthritis Research Laboratories, Department of Rheumatology, Institute of Bone and Joint Research, The University of Sydney at Royal North Shore Hospital, St Leonards, New South Wales, Australia. Electronic address: mlxue@med.usyd.edu.au.
authors.forename: Meilang
authors.initials: M
authors.lastname: Xue
authors.affiliation: Sutton Arthritis Research Laboratories, Department of Rheumatology, Institute of Bone and Joint Research, The University of Sydney at Royal North Shore Hospital, St Leonards, New South Wales, Australia.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Jackson
mesh_terms: D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D066246:ErbB Receptors / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D006801:Humans; D015603:Keratinocytes / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology
chemical_list: D034741:RNA, Small Interfering; C512478:EGFR protein, human; D066246:ErbB Receptors; D048049:Extracellular Signal-Regulated MAP Kinases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9