Expression of exosomal miR-21 and miR-29 in serum of children and adolescents with T1DM and persistent microalbuminuria

Abstract Background Although microalbuminuria is the earliest marker for DN, its presence is not necessarily linked to DN diagnosis or progression in some patients. Therefore, the factors that play a role in the pathogenesis of DN must be clarified, especially in juvenile-onset T1DM patients. Aim of study We aimed to investigate expression of serum exosomal miR-21 and miR-29 in children and adolescents with T1DM and persistent microalbuminuria. Subjects and Methods Exosomal miR-21 and miR-29 were assayed in serum of 120 T1DM patients (60 with normoalbuminuria and 60 with persistent microalbuminuria) and 60 healthy subjects using quantitative reverse transcriptase PCR (qRT PCR). Results Expression of miR-21 and miR-29 was significantly elevated in patients with or without microalbuminuria than in controls (p = 0.02, 0.0 and 0.001, 0.006) with no significant difference in miR-21 level between the two patients' groups. Expression of miR-29 was significantly elevated in patients with microalbuminuria compared to patients without microalbuminuria (p = 0.003). Confirmation of association of miR-29 with T1DM and persistent microalbuminuria was done using regression analysis after adjustment of age, sex, BMI, disease duration, total cholesterol, triglycerides, HDL and LDL (p = 0.005, 0.01 respectively). ROC analysis showed miR-29 is a marker of persistent microalbuminuria (P = 0.003). Conclusion Elevated expression of miR-29 may play a role in pathogenesis of T1DM and associated DN and might represent a potential biomarker for early diagnosis of diabetic nephropathy in pediatric patients and a future target for therapy.