Evaluation of Osteopontin Gene Expression in Endometrium of Diabetic Rat Models Treated with Metformin and Pioglitazone

BACKGROUND: Osteopontin (Opn) is one of the co-factors involved in cell adhesion and invasion during the implanta- tion process. Several reports have shown Opn expression changes in diabetic condition in several tissues. In addition, an increased incidence of spontaneous abortion is reported in diabetic women. We, therefore, designed a study to eval- uate the effects of diabetes on Opn expression at implantation time after treatment with metformin and pioglitazone. MATERIALS AND METHODS: In this interventional and experimental study, 28 rats were randomly divided into four groups, namely control, diabetic, pioglitazone-treated diabetic rats and metformin-treated diabetic rats. Streptozo- tocin (STZ) and nicotinamide (NA) were used to induce type 2 diabetes (T2D). During the implantation window, the endometrium was removed and the expression of Opn was analysed by reverse transcription quantitative polymerase chain reaction (RT-qPCR). RESULTS: Opn expression was significantly higher (30.70 fold-changes) in the diabetic group in comparison with the control group (P=0.04). Furthermore, the expression of Opn was significantly lower in the diabetic group treated with pioglitazone when compared with the diabetic group (P=0.04). CONCLUSION: According to the high Opn expression and the possibility of increased adhesion of endometrial epithelial cells, the invasion of blastocyst may be affected and thus reduced. As pioglitazone significantly reversed the upregula- tion of Opn in diabetic rats, it may be considered as a therapeutic compound for treating T2D.