Taurine Transporter Gene Expression in Mononuclear Blood Cells of Type 1 Diabetes Patients.

Background. Taurine transporter gene expression (RNA-TauT) has a role in retinal cell function and is modulated in vitro and in vivo by hyperglycemia and/or oxidative stress. This study was aimed at testing whether RNA-TauT gene expression is modified in blood mononuclear peripheral cells (MPCs) of type 1 diabetic patients, is related to plasma markers of oxidative stress or endothelial dysfunction, or, finally, is related to presence of retinopathy. Methods. RNA-TauT was measured in MPCs by real-time PCR-analysis in 35 type 1 diabetic patients and in 33 age- and sex-matched controls, additionally measuring plasma and cell taurine and markers of oxidative stress and endothelial dysfunction. Results. RNA-TauT, expressed as , was significantly higher in MPCs of type 1 diabetic patients than in controls [median (interquartile range): 1.32(0.31) versus 1.00(0.15); ]. In diabetic patients RNA-TauT was related to HbA1c (; ) and inversely to plasma homocysteine (; ) being additionally significantly higher in MPCs of patients without retinopathy [(); 1.36(0.34)] compared to those with retinopathy [(); 1.16(0.20)], independently from HbA1c or diabetes duration. Conclusions. RNA-TauT gene expression is significantly upregulated in MPCs of type 1 diabetes patients and is related to HbA1c levels and inversely to plasma homocysteine. Finally, in diabetes patients, RNA-TauT upregulation seems to be blunted in patients with retinopathy independently of their metabolic control or longer diabetes duration.