Expression of Exosomal Mir-21 and Mir-29 in Serum of Children and Adolescents with T1DM and Persistent Microalbuminuria

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.