2/12/2014 Roberta A. Gottlieb, M.D. Roberta A. Gottlieb, M.D. - PDF document

2/12/2014 Roberta A. Gottlieb, M.D. Roberta A. Gottlieb, M.D. Cedars Cedars-Sinai Heart Institute Sinai Heart Institute Barbra Streisand Women’s Heart Center Barbra Streisand Women’s Heart Center February 7, 2014 February 7, 2014 AHA’s Go AHA’s Go Red Red for Women Day for Women Day • Caloric restriction and lifespan • Autophagy • Cellular housekeeping and aging • Organism vs organ vs cell vs organelle age • Heart and T-cells • Hungry mice • Prospects for the future and summary • Years of existence since birth • Turnover of cells in an organ • Turnover of organelles within a cell • Turnover of proteins within organelles, cells • Neutrophils live 1-2 days • Heart, brain, and T memory cells live decades • Cellular housekeeping is important! 1

2/12/2014 • Calorie restriction: 20-40% less than usual, but with optimal nutrition and vitamins • Normal may be 1500-2000 cal/day, so 40%CR would be 900-1200 cal/day • Studies in worms, flies, mice, rats, and rhesus monkeys show increase in lifespan from CR • Benefits due to lower risk of cancer and heart disease • 18 adults voluntarily adopted CR for ~6yr (ages 35-82 yr) • Weight and BMI decreased in first year (BMI: 24  19) • Cholesterol and triglycerides decreased to levels better than most 20-year-olds • Fatty streaks in arteries were minimal • Reduced abdominal fat and lower CRP • In severe CR: anemia, muscle loss, lethargy, depression • In moderate CR: Bone loss and decreased muscle mass but normalized by exercise 2

2/12/2014 • Increased risk of heart disease, high blood pressure, and stroke • Increased risk of type 2 diabetes • Increased risk of cancer (uterus, gallbladder, cervix, ovary, breast, colon, prostate) • Double the rate of developing osteoarthritis • Increased risk of Alzheimer’s • Induced by fasting, exercise, and CR • Suppressed by overnutrition, insulin excess, protein or carbohydrate excess • Breaks down proteins and organelles inside every cell (recycling) • Clears out cellular debris • Forces recycling of old organelles Pre-autophagosomal structure Mitochondrion Beclin-1 Atg5-Atg12 Phagophore Autophagolysosome p62 LC3 LC3 Autophagosome Lysosome Modified from T. Shintani et al., Science 306, 990 -995 (2004) 3

2/12/2014 • Alzheimer’s, Parkinson’s, and heart failure are characterized by accumulation of damaged mitochondria and protein aggregates • Genetic and protein analysis reveals defects in autophagy in these diseases • These conditions are accelerated in obese individuals 4

2/12/2014 PINK1 PINK1 accumulates Parkin Parkin translocates Signaling or stress and ubiquitinates ubiquitinates targets triggers mitochondrial depolarization p62 p62 translocates and recruits LC3/autophagosome LC3/autophagosome Adapted from Shirihai, based on Youle & Narendra, Nature Rev. Molec Cell Bio 12 , 9-14 80 Infarct Size (% Area at risk) 60 * 40 20 0 WT WT PKO PKO Statin - + - + Allen Andres, Genaro Hernandez, et al. Antioxidant and Redox Signaling 2013 Parkin KO PINK1 KO Mitophagy Overnutrition Age MitoROS ↓ ΔΨ m mtDNA NF k B NLRP3 Inflammatory cytokines TLR9 5

2/12/2014 10 Wild type (relative to non-ischemic zone) Parkin KO Fold Induction 5 0 TNF- α IL-1 β IL-6 Phyllis Linton, Chengqun Huang, unpublished data Excess insulin signaling and Impaired autophagy prevents cardioprotection via nutrient excess (amino acids, mitophagy, and results in accumulation of fats) suppress autophagy inefficient mitochondria that generate excess ROS Aging downregulates ROS signaling triggers NF k B autophagy gene expression translocation and assembly of mitochondria mitochondria the inflammasome, leading to cytokine production nucleus Inflammatory cytokines exacerbate acute and chronic ROS cardiomyocyte reperfusion injury through cardiomyocyte effects on immune cells, fibroblasts, endothelial cells, endothelial cells and cardiomyocytes inflammatory Impaired mitophagy, ROS, cells and inflammation exacerbate fibroblasts TNF a TNF postinfarction remodeling IL- IL -6 IL- IL -18 18 7mo 7mo 11mo 11mo 7mo 7mo WT WT+CQ KO KO+CQ KO KO+CQ LC3-I LC3-II Autophagic Flux in Liver Tissue 1.2 actin wt a ko a 1 0.8 LC3-II / actin 0.6 0.4 0.2 Mouse i.p. injections: n= n=6 n=3 n=6 0 Chloroquine (CQ): 50ug/g 3 cq- cq+ Saline: 10ul/g 6

2/12/2014 Mitochondrial Parkin Mitochondria normalized to Ctrl Pixel intensity 1.5 WT KO p<0.0025, n=5 1.0 Parkin ↓ ΔΨ 0.5 TOM70 0 WT KO CypD Cytosolic Parkin Cytosol normalized to Ctrl 3 Pixel intensity WT p<0.0025, n=5 KO 2 Parkin 1 GAPDH 0 WT KO Parkin CyD KO 1 CyD KO 2 WT 1 •16 month old C57BL/6 male CyD-/- and WT mice •100% (6/6) of CyD-/- mice developed liver tumors •No hepatic tumors detected in age-matched WT mice Master’s Degree thesis project: Xinghao Zhang 7