1. Micro-RNA: which role do they play in Structural and Electrical remodeling in Heart?

2. Micro-RNA: which role do they play in Structural and Electrical remodeling in Heart ? What is a micro-RNA (or miR) ? - Single stranded RNA molecules (20 to 23 nucleotides) - Regulatory molecules (30% of genes seem to be regulated by miR) - Multi-organism (C.Elegans, Drosophilae, mammalians, plants,…)

3. Where are miR coming from ? Micro-RNA: which role do they play in Structural and Electrical remodeling in Heart ? non coding DNA Primary transcripts pri-miR Stem-loop structured pre-miR P68/p72 DROSHA/DGCR8 miR DICER

4. Micro-RNA: which role do they play in Structural and Electrical remodeling in Heart ? How can we study miR ? With different models of Mice : With different tools like : Mouse knocked-out for Dicer Mouse with induced cardiac insufficiency Micro-array ship Comparison old mice and young mice (Aging Project) Q-PCR (Sybr-green, Taq-man)

5. Micro-RNA: which role do they play in Structural and Electrical remodeling in Heart ? Results for the aging project: Using 2 old mice (22 months) and two young (8 weeks) No variation in the pattern of expression of micro-RNAs

6. Micro-RNA: which role do they play in Structural and Electrical remodeling in Heart ? 1 st results for the KO-DICER project: Induction of the knock-out with Tamoxifen Specific to cardiomyocytes 1 st protocol used : - 0.5 mg of tamoxifen injected for 10 days. - 2 weeks of rest. - 1 mg of tamoxifen injected for 5 days. - 10 days of rest. miR up-regulated : miR21 miR 199 miR 195 miR down-regulated :miR 1 miR 133 (a,b) miR 30 Hypertrophy noticeable

7. Micro-RNA: which role do they play in Structural and Electrical remodeling in Heart ? 2 nd results for the KO-DICER project: Induction of the knock-out with Tamoxifen Specific to cardiomyocytes 2 nd protocol used : - 1 mg of tamoxifen injected for 5 days. - 2 days of rest. Hypertrophy no noticeable miR up-regulated : miR21 miR 199 miR down-regulated :miR 133 (a,b) miR 30

8. 3 rd results for the KO-DICER project: Induction of the knock-out with Tamoxifen Specific to cardiomyocytes 3 nd protocol used : - 1 mg of tamoxifen injected for 5 days. - 2 days of rest. -1 mg of tamoxifen for 5 days. - 3 weeks of rest. Micro-RNA: which role do they play in Structural and Electrical remodeling in Heart ? Hypertrophy no noticeable Only DICER looks to be reduced (by 2.3 times or 58 %). What happen to DICER ?