Downregulated gene expression in human palate fibroblasts after cyclosporin A treatment.

BACKGROUND

Cyclosporin A is a powerful immunosuppressive drug with considerable impact on transplants and is able to modify extracellular matrix (ECM) composition. It has recently been demonstrated that cyclosporin A stimulates the production of the cytokine family. Cytokines such as interleukin, transforming growth factor beta(1), and bone morphogenetic protein induce the deposition of glycosaminoglycans (GAGs), proteoglycans, and collagen fibers in the connective ECM. ECM composition is very important for normal tissue development and function. In this work, we examine the effects caused by cyclosporin A on cultures of normal human palate fibroblasts in order to evaluate interleukin, transforming growth factor beta II, and bone morphogenetic protein II membrane receptor induction and extracellular GAG changes such as hyaluronic acid, heparin sulfate, and chondroitin sulfate.

METHODS

Palate fibroblasts were maintained for 24 h in serum-free 199 medium containing 5 microg/mL (3)H glucosamine hydrochloride. After this time, TGF II and BMP II receptors were determined by microarray analysis and GAG classes by the biochemical method.

RESULTS

The results show that TGFbeta(1) II and BMP II membrane receptors are significantly inhibited in cyclosporin A-treated cultures as compared to controls, whereas IL-1R2 membrane receptors are stimulated. The behavior of total intra- and extracellular GAGs is significantly increased in cyclosporin A-treated cultures, whereas the ratio between non-sulfated/sulfated GAGs decreases (p <or=0.01) vis-à-vis controls.

CONCLUSIONS

Because they form a highly complicated macromolecular network in the ECM, which provides an indication of cell function and gene expression and modulates growth factor activities, GAG changes are related to modification of ECM functions. Our data show that cyclosporin A causes biochemical changes to ECM through alterations in cytokines and respective membrane receptor linkages.