Recombinant dnase

Total RNA was extracted by RNeasy mini kit (QIAGEN) according to the manufacturer’s instructions. The integrity of the RNA was assessed by denaturing agarose gel electrophoresis (presence of sharp 28S, 18S, and 5S bands) and spectrophotometry (NanoDrop 2000, Thermo Scientific). Total RNA was purified to eliminate potentially contaminating genomic DNA using recombinant DNase (QIAGEN).

Brain and heart tissues were first pulverized and then split to extract DNA and RNA. DNA was extracted from liquid nitrogen–pulverized mouse tissues using DNeasy Blood & Tissue Kit (Qiagen, Hilden, Germany), according to the manufacturer’s instructions. The quality of DNA was checked using NanoDrop 2000 (Thermo Scientific). DNA was quantified using Qubit 2.0 Fluorometer with the dsDNA broad range assay kit (Invitrogen, Q32850). Total RNA from tissues was extracted using RNeasy mini kit (QIAGEN) following the manufacturer’s instructions. The integrity of the RNA was determined using NanoDrop 2000 (Thermo Scientific). Recombinant DNase (QIAGEN) was used to remove potentially contaminating genomic DNA.

For DNase treatment, 20 μL of cell free serum was incubated with 10 mU of recombinant DNase (Qiagen) for 30 min at 37 °C followed by detection with PicoGreen™ reagent. EVs from serum were isolated using the Total Exosome Isolation Kit from serum (Invitrogen, Carlsbad, CA, USA) according to the manufacturer’s recommendations.