Differential miRNA expression profiling of urinary exosomes from normo- and microalbuminuric type 1 diabetic patients

The aim of this study was to compare miRNA expression in urinary exosomes from type 1 diabetic patients with and without incipient diabetic nephropathy. Overnight urine collections were obtained from normo- and microalbuminuric type 1 diabetic patients. Urines were pre-cleared by both centrifugation and filtration, urinary exosomes were isolated by two consecutive ultracentrifugation steps and total RNA extracted. Differential miRNA profiling was performed using a Human TaqMan miRNA Array A on an 7900HT Fast Real-Time PCR System. Results showed that expression of 22 urinary exosomal miRNAs differed in incipient diabetic nephropathy. Differential qPCR miRNA profiling was performed on urinary exosomes from 2 pairs of micro/normoalbuminuric type 1 diabetic patients comparable for age, sex, diabetes duration, and tightly matched for HbA1c (1° pair: 8.1 vs. 8.1, 2° pair: 8.7 vs. 8.7). MiRNAs were considered differentially expressed if they exhibited greater than twofold expression differences in both pairs.