The Alzheimer's Disease Neuroimaging Initiative (ADNI) is a longitudinal multisite observational study of healthy elders, mild cognitive impairment (MCI), and Alzheimer's disease. Magnetic resonance imaging (MRI), (18F)-fluorodeoxyglucose positron emission tomography (FDG PET), urine serum, and cerebrospinal fluid (CSF) biomarkers, as well as clinical/psychometric assessments are acquiredat multiple time points. All data will be cross-linked and made available to the general scientific community. The purpose of this report is to describe the MRI methods employed in ADNI. The ADNI MRI core established specifications thatguided protocol development. A major effort was

SUMMARY Exercise induces physiological cardiac growth and protects the heart against pathological remodeling. Recent work suggests exercise also enhances the heart’s capacity for repair, which could be important for regenerative therapies. While microRNAs are important in certain cardiac pathologies, less is known about their functional roles in exercise-induced cardiac phenotypes. We profiled cardiac microRNA expression in two distinct models of exercise and found microRNA-222 (miR-222) was upregulated in both. Downstream miR-222 targets modulating cardiomyocyte phenotype were identified, including HIPK1 and Homeobox-1. Inhibition of miR-222 in vivo completely blocked cardiac and cardiomyocyte growth in response to exercise, while reducing markers of cardiomyocyte proliferation. Importantly, mice with inducible cardiomyocyte miR-222 expression were resistant to adverse cardiac remodeling and dysfunction after ischemic injury. These studies implicate miR-222 as necessary for exercise-induced cardiomyocyte growth and proliferation in the adult mammalian heart and show that it is sufficient to protect the heart against adverse remodeling.

Limited microRNAs (miRNAs, miRs) have been reported to be necessary for exercise-induced cardiac growth and essential for protection against pathological cardiac remodeling. Here we determined members of the miR-17-92 cluster and their passenger miRNAs expressions in two distinct murine exercise models and found that miR-17-3p was increased in both. miR-17-3p promoted cardiomyocyte hypertrophy, proliferation, and survival. TIMP-3 was identified as a direct target gene of miR-17-3p whereas PTEN was indirectly inhibited by miR-17-3p. Inhibition of miR-17-3p in vivo attenuated exercise-induced cardiac growth including cardiomyocyte hypertrophy and expression of markers of myocyte proliferation. Importantly, mice injected with miR-17-3p agomir were protected from adverse remodeling after cardiac ischemia/reperfusion injury. Collectively, these data suggest that miR-17-3p contributes to exercise-induced cardiac growth and protects against adverse ventricular remodeling. miR-17-3p may represent a novel therapeutic target to promote functional recovery after cardiac ischemia/reperfusion.