OBJECTIVETo investigate the effects of chitosan on the biological activities of the fibroblasts derived from different tissues.

METHODSThe biological activities of the fibroblasts derived from different tissues were evaluated with a MTT method for fibroblast proliferation, photic and electronic microscope for morphologic and subcellular structure, 3H-proline uptake method for collagen secretion and ELISA box for the secretion of TGF-beta 1, FGF-AB, and IL-8.

RESULTSThis study showed that the chitosan inhabited the proliferation of the fibroblasts and the secretion of the TGF-beta 1, FGF-AB and collagen of the fibroblasts with a dose-depended manner in the normal skin, hypertrophic scar and keloid groups, but it stimulated the IL-8. However, there were no significant differences among the three groups (P > 0.05).

CONCLUSIONThe chitosan could inhibit the growth, proliferation, biosynthesis and secretion of the fibroblasts, and it may be used to treat different scars.

Adolescent ; Adult ; Cell Division ; drug effects ; Chitin ; analogs & derivatives ; pharmacology ; Chitosan ; Dose-Response Relationship, Drug ; Female ; Fibroblast Growth Factors ; secretion ; Fibroblasts ; drug effects ; metabolism ; ultrastructure ; Hemostatics ; pharmacology ; Humans ; Interleukin-8 ; secretion ; Male ; Microscopy, Electron ; Peptide Fragments ; secretion ; Transforming Growth Factor beta ; secretion

Cholesterol is one of major components of cell membrane and plays a role in vesicular trafficking and cellular signaling. We investigated the effects of cholesterol on matrix metalloproteinase-2 (MMP-2) activation in human dermal fibroblasts. We found that tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) expression and active form MMP-2 (64 kD) were dose-dependently increased by methyl-beta-cyclodextrin (MbetaCD), a cholesterol depletion agent. In contrast, cholesterol depletion-induced TIMP-2 expression and MMP-2 activation were suppressed by cholesterol repletion. Then we investigated the regulatory mechanism of TIMP-2 expression by cholesterol depletion. We found that the phosphorylation of JNK as well as ERK was significantly increased by cholesterol depletion. Moreover, cholesterol depletion-induced TIMP-2 expression and MMP-2 activation was significantly decreased by MEK inhibitor U0126, and JNK inhibitor SP600125, respectively. While a low dose of recombinant TIMP-2 (100 ng/ml) increased the level of active MMP-2 (64 kD), the high dose of TIMP-2 (> or = 200 ng/ml) decreased the level of active MMP-2 (64 kD). Taken together, we suggest that the induction of TIMP-2 by cholesterol depletion leads to the conversion of proMMP-2 (72 kD) into active MMP-2 (64 kD) in human dermal fibroblasts.
Anthracenes/pharmacology ; Butadienes/pharmacology ; Cells, Cultured ; Child ; Child, Preschool ; Cholesterol/metabolism/*physiology ; Cyclodextrins/pharmacology ; Enzyme Inhibitors/pharmacology ; Extracellular Signal-Regulated MAP Kinases/antagonists & inhibitors/physiology ; Fibroblasts/*drug effects/*metabolism/ultrastructure ; Humans ; Immunoblotting ; Immunoprecipitation ; JNK Mitogen-Activated Protein Kinases/antagonists & inhibitors/physiology ; Matrix Metalloproteinase 2/*metabolism ; Microscopy, Electron, Transmission ; Nitriles/pharmacology ; Tissue Inhibitor of Metalloproteinase-2/*metabolism