[Mevastatin inhibits the differentiation of thyroid-associated ophthalmopathy derived orbital preadipocytes].

OBJECTIVE

To investigate the effect of mevastatin (Mev) on the expression of peroxisome-proliferator-activated receptor-gamma (PPAR-gamma) mRNA and differentiation of Thyroid-associated ophthalmopathy (TAO) derived orbital preadipocytes in vitro.

METHODS

Orbital adipose tissues were obtained from TAO patients undergoing orbital decompression surgery. The orbital preadipocytes cultured from the orbital adipose tissues were divided into Group A (a control group) and Group B (an intervention group). Group B was subdivided into Group B1-B5, all groups were stimulated to differentiate into mature adipocytes with cocktail differentiation medium.The entire course of differentiation was 10 d. The differentiation of orbital preadipocytes in Group A was induced with routine inducer,while at in Group B1,B2, and B3 was interfered with 5 micromol/L (B1), 10 micromol/L(B2),20 micromol/L (B3) mevastatin respectively during the whole process of differentiation. The differentiation of orbital preadipocytes in Group B4 and B5 was interfered with 10 micromol/L mevastatin day 4 (B4) or day 8 (B5) of the differentiation process until the entire course was over. Intracellular fat accumulation in differentiated adipocytes was determined by oil red O staining. The value of optical absorption was measured at 492 nm with enzyme-linked immunosorbent assay. The expression of PPAR-gamma mRNA was detected by reverse transcription polymerase chain reaction.

RESULTS

The light absorption value (A) and PPAR-gamma mRNA expression of differentiated cells in Group A,B1,B2,and B3 decreased successively,and there was significant difference in any of the 2 groups among Group A, B1 and B2, and B3 (P<0.05). The value A and PPAR-gamma mRNA expression of differentiated cells in Group A, B4, and B2 decreased successively, and the difference in any of the 2 groups among these 3 groups was significant. However, there were no significant difference between Group A and B5.

CONCLUSION

Mevastatin inhibits the differentiation of TAO derived orbital preadipocytes by blocking PPAR-gamma mRNA expression. The degree of inhibition is not only concentration-dependent but also associated with the stage of differentiation. The earlier the differentiation, the stronger the inhibition.