Cell function in gingival tissue seems to be governed by the extracellular matrix and soluble factors in the local environment. Accordingly, in this study, the effect of extracellular matrix materials on oral mucosal keratinocyte (OMK) and oral mucosal fibroblast (OMF) proliferation, matrix synthesis, and the response to transforming growth factorβ (TGF-β) was investigated.
After culturing keratinocytes and fibroblasts on tissue culture dishes coated with type I collagen (CI), type IV collagen(C IV), laminin (LM), and fibronection (FN) for 4 days, the cells were counted with a CytoFluor II fluorescence multiplate reader. Ability to synthesize collagen-associated proteins and proteoglycans (PGs) was measured by the metabolic labeling method using
14C-proline and
35S-sulfate, and fluorograms were prepared and evaluated. All experiments were performed with and without the addition of TGF-β, and the results were as follows:
1. All four types of matrix material significantly promoted OMK proliferation. OMF proliferation, on the other hand, was significantly promoted by LM and FN.
2. TGF-β significantly inhibited OMK proliferation on all of the matrix materials, including plastic, but OMF proliferation was significantly inhibited on plastic alone.
3. Among the major collagen-associated proteins, C I,C IV and FN significantly promoted OMF synthesis of 190-kDa and 170-kDa proteins, and C I and C IV significantly inhibited OMF synthesis of 140-kDa and 120-kDa proteins. TGF-β significantly promoted the synthesis of 170-kDa protein on C IV, and synthesis of 140-kDa and 120-kDa proteins on C I.
4. PG synthesis by OMKs yielded only PG-1,and this was significantly promoted by C I and LM. TGF-β significantly inhibited PG synthesis only on CI.
5. OMFs were found to express PG-I and PG-II, and all of the matrix materials promoted the synthesis of PG-I and PG-II. TGF-β significantly promoted the synthesis of PG-I on LM only, and the synthesis of PG-II on C I, C IV, and LM.
The above results show that the four different types of extracellular matrix material examined alter keratinocyte and fibroblast proliferation and matrix synthesis. In a similar manner, differences in the characteristics of the extracellular matrix cause changes in the cell response to TGF-β.These results show that the components of the extracellular matrix have important effects on the growth and differentiation of OMKs and OMFs, and on the action of soluble factors, suggesting that determination of these distinctive properties will make it possible to apply them to a variety of biomaterials.
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