Male Dicer1fl/fl mice on a mixed 129S4, C57Bl/6 strain background30 (link) were crossed with C57Bl/6 Alb-Cre+/− mice31 (link) to generate Dicer1fl/fl, Alb-Cre+/− mice. To specifically investigate the impact of miRNAs on mature liver function, we initiated Cre recombinase expression in 8- to 10-week-old mice. For this purpose, we used a double-stranded AAV vector that affords more rapid and efficient transgene expression than conventional AAV vectors by bypassing the need for conversion from a single-stranded to a double-stranded state after transduction.32 (link) To restrict Cre expression to hepatocytes, we used a hepatocyte-specific transthyretin (Ttr) promoter and pseudotyped the vector genome with capsids from AAV8, a serotype that can transduce virtually all hepatocytes in vivo without causing toxicity.33 (link) The AAV8-Ttr-Cre vector is highly efficient and can delete the floxed Dicer1 sequences in all hepatocytes within 48 hours.
Male C57Bl/6 mice (8 weeks old) were maintained on an HFD (Open Source D12492) for 8 weeks. The mice were then divided into two groups; one group was treated with miR-24-ASO (anti-sense oligonucleotide) and the other was treated with miR-24-MM-ASO (control scramble) for 4 weeks. At the 12th week, the mice were anesthetized and blood was collected by way of cardiac puncture. Subsequently, the livers were harvested and immediately frozen in liquid nitrogen and stored at −80°C for further analysis.
Male C57Bl/6 mice (8 weeks old) were maintained on an HFD (Open Source D12492) for 8 weeks. The mice were then divided into two groups; one group was treated with miR-24-ASO (anti-sense oligonucleotide) and the other was treated with miR-24-MM-ASO (control scramble) for 4 weeks. At the 12th week, the mice were anesthetized and blood was collected by way of cardiac puncture. Subsequently, the livers were harvested and immediately frozen in liquid nitrogen and stored at −80°C for further analysis.