Mouse il 1β

Ex vivo microglia were treated for 24 hours with 50 ng/mL of mouse IL‐1β or 30 ng/mL of mouse IL‐4 (Miltenyi, France) or 10 ng/mL of LPS‐EB Ultrapure (Sigma, France). Cells were incubated with 10 nM of 17(S)‐Rvd1 (Bertin Pharma, France) for 30 minutes before addition of LPS. Ex vivo microglia were first treated with 200 ng/mL of 3DNA Cy3 miR‐146b‐5p or 3DNA Cy3 scramble negative miRNA (miR SCR; Stock solutions 225 ng/uL 3DNA, 1.557uM siRNA, Genisphere, USA) for 6 hours and then stimulated for 24 hours with LPS or IL‐1β.
Mouse pups were injected by i.p. way at P0 and at P1 in the morning with either 3DNA Cy3 miR‐146b‐5p or 3DNA Cy3 miR SCR (200 ng/injection) along with either PBS or IL‐1β. At P3, animals were euthanized 2 hours after PBS or IL‐1β injections. For long‐term studies 3DNA co‐injection was also done at P3. To analyze uptake of 3DNA in the brain, animals were euthanized 4 hours after i.p. injection at P1. The 3DNA injected by i.p. way crossed the blood–brain‐barrier to target microglia.¹⁰

Mouse IL-1β was purchased from Miltenyi Biotech (Bergisch Gladbach, Germany). The peptide was dissolved in deionized sterile-filtered water and aliquots were stored at −20 °C. The final concentrations used were 1.4 nM (IL-1β). Chinese-hamster-ovary-derived recombinant mouse IFN-α from Hycultec GmbH (Beutelsbach, Germany) was used with a final concentration of 1000 IU ml⁻¹.