OBJECTIVE: To review the role of matrix metalloproteinase-1 (MMP-1) in the course of healing in wounded skin. METHODS: The recent literatures on MMP-1 in skin wound repair were reviewed, which gave the insight into the local effect of MMP-1 during re-epithelialization. RESULTS: Following injury, basal keratinocytes, moving from the wound edge and interact with dermal matrix proteins in the wound bed, were induced to express MMP-1 in a specific space-time pattern. MMP-1 cleaved the collagen, thereby altering its structure and affinity by which the keratinocytes binded it. MMP-1 served a beneficial role in wound healing by facilitating the proliferation and movement of keratinocytes over the collagen-rich wound bed during re-epithelialization. CONCLUSION: MMP-1 expression of migrating keratinocytes directly influences the re-epithelialization during the course of healing of the wounded skin.
Objective To investigate the proliferation inhibitory effect and to explore the molecular mechanism of curcumin on pulmonary fibroblasts. Methods Fibroblasts derived from lung tissue of patients with idiopathic pulmonary fibrosis ( IPF) was cultured in vitro and incubated with curcumin at different concentrations for different time. Fibroblasts were randomized into 5 groups, ie. a control group and 4 curcumin groups ( intervened by 5, 10, 20, 40 μmol / L curcumin, respectively) . MTT assay was used to determine the inhibitory rate of curcumin on the proliferation of pulmonary fibroblasts. Apoptosis and the Caspase-3 expression of pulmonary fibroblasts were identified by flow cytometry ( FCM) . Variables were compared with One-Way ANOVA. The correlations between variables were analyzed using Pearson’scorrelation coefficient. Results Curcumin inhibited pulmonary fibroblasts proliferation in a dose-dependent and time-dependent manner( r =0. 886, r = 0. 832, respectively, all P lt; 0. 01) . Apoptosis rate of pulmonary fibroblasts in 4 curcumin groups was ( 29. 58 ±2. 13) % , ( 64. 36 ±3. 92) %, ( 72. 98 ±4. 42) % , ( 83. 14 ±2. 51) % , respectively, which was significantly higher than that in the control group[ ( 3. 84 ±1. 88) % , P lt;0. 01] . The positive expression rate of apoptosis-regulating protein caspase-3 was ( 26. 24 ±3. 64) % ,( 44. 87 ±5. 31) % , ( 57. 44 ±4. 23) % , ( 73. 65 ±5. 01) % , respectively, which was significantly higher than that of the control group[ ( 4. 02 ±0. 62) % , P lt; 0. 01] . Conclusions In vitro, curcumin can significantly inhibit proliferation and induce apoptosis of pulmonary fibroblasts of patients with IPF. The mechanism maybe associated with up-regulating expression of Caspase-3.