NIAID and NIDDK Workshop May 10 th, 2016

Transcription

1 Developing a Comprehensive Therapeutic Research Strategy for the Converging Epidemics of TB, T2DM, and HIV NIAID and NIDDK Workshop May 10 th, 2016 Metabolite-Induced ROS Overproduction Activates the Diverse Biochemical and Molecular Mechanisms Underlying Diabetic Complications Michael Brownlee, M.D. Anita and Jack Saltz Chair in Diabetes Research Associate Director for Biomedical Sciences, Einstein Diabetes Research Center Professor of Medicine and Pathology Albert Einstein College of Medicine New York

2 Physiologic ROS production is essential for normal intracellular signaling and cellular homeostasis Holmström, K.M. & Finkel, T. Nature Reviews Molecular Cell Biology 15, , 2014

3 Current view of ROS stress Nathan, C., and Cunningham-Bussel, A. Nat Rev Immunol 13: , 2013

4 The diabetic complications epidemic Leading cause of blindness in working age adults Diabetic Retinopathy Stroke 2- to 4- fold increase in stroke and dementia Diabetic Nephropathy Leading cause of end-stage renal disease 20-50% of T2D, 33% of T1D Increased risk of CVD and death CVD: 2/3 of heart attack pts. have diabetes or IGT Cardiovascular Disease Diabetic Neuropathy Leading cause of non-traumatic lower extremity amputations

5 Hyperglycemia- and FFA-induced overproduction of ROS activates all major pathways of diabetic cellular damage Cytoplasm Glucose/FFA ROS PARP GAPDH Nucleus Polyol PW flux Methylglyoxal RAGE & RAGE ligands AGE PKC Hexosamine PW flux NFκB Modified from Brownlee M., Nature, 2001; 4104:813-82

6 Superoxide also inhibits critical endothelial enzymes Zhao, H.J., et al. J. Am. Soc Nephrol 17: , 2006 ; Nasu, T., et al., Am J Phys Renal Phys 302:F1616-F1629, 2012 Endothelial nitric oxide synthase (enos) KD Prostacyclin synthase (PGI 2 ) KD

7 Recently described mechanisms of diabetic tissue damage activated by metabolite-induced overproduction of ROS Nuclear import of NFAT transcription factors Nuclear translocation of FOXO transcription factors PPARα nuclear receptor expression CaMKII activation/increased intracellular Ca ++ Decreased sirtuin 1, PGC1α, AMPK expression Downregulation and mismatching of specific mirnas NRLP3 inflammasome activation Neutrophil extracellular trap formation/mφ priming Shah, M.S., and Brownlee, M. Circ Res in press, 2016

8 Transgenic expression of the antioxidant enzyme superoxide dismutase prevents each complication in experimental diabetes Diabetic retinopathy Diabetic nephropathy Diabetic neuropathy Diabetic cardiomyopathy

9 Post-translational modifications of histones cause chromatin remodeling and changes in levels of gene expression

10 Hyperglycemia-induced ROS cause activating modifications of histone 3 lysine 4 and de-repressing modifications of histone 3 lysine 9 at the NFκB p65 proximal promoter El-Osta, A., et al. J Exp Med, 2008, 205:2409

11 In non-diabetic mice, transient hyperglycemia induces a long-term increase in H3K4me1 at the NFκB p65 promoter by recruiting the histone methyltransferase Set 7 qpcr for NFκB p65 promoter after LCM and cchip by H3K4me1 (Arbitrary Units) LG(6h) HG(6h) HG(6h)+LG(2d) HG(6h)+LG(4d) HG(6h)+LG(6d) LG(6d) * * * Treatment Group (clamped mice) * El-Osta, A., et al. J Exp Med, 2008, 205:2409

12 In non-diabetic mice, six hours of transient hyperglycemia causes a six DAY increase in NFκB expression, a master regulator of inflammatory genes El-Osta, A., et al. J Exp Med, 2008, 205:2409

13 After transient hyperglycemia, elevated mitochondrial ROS production persists for days 5mM glucose 25mM glucose 25mM glucose + 5mM glucose 010 ROS (noml/mg protein) * * * * h 6h 6h+vector 6h+MnSOD 6h+2d 6h+5d Ferdinando Giacco et al. Diabetes 2015;64:

14 Transient exposure to hyperglycemia above a critical threshold level activates a multi-component positive feedback loop Ferdinando Giacco et al. Diabetes 2015;64:

15 ROS-induced methylglyoxal adducts accumulate in TB lesions of patients Rachman H, Kim N, Ulrichs T, Baumann S, Pradl L, et al. (2006). PLoS ONE 1(1): e29. doi: /journal.pone

16 TNF-induced mitochondrial ROS in TB-infected macrophages increases killing of mycobacteria, but increases necroptosis and mycobacterial release into the extracellular milieu and bacterial dissemination Roca, F.J and Ramakrishnan, L. Cell 153: , 2013; Van Heijst, H.W.J, and Pamer, E.G. Cell 153: , 2013

17 Colleagues who contributed to the work presented today Brownlee Lab Anna Carratu Xueliang Du Diane Edelstein Ida Giardino Ferdinando Giacco Qida Ju Takeshi Matsumura Takeshi Nishikawa Manasi Shah Guanghi Sui Tetsuya Taguchi Collaborators Naila Ahmed Angelika Bierhaus Mark Cooper Stephanie Dimmeler Ajit S. Divakaruni Assam El-Osta Hans-Peter Hammes Anne N.Murphy Peter Nawrroth Alessandro Pocai Robert Roeder Vijay P. Sarthy Philip Scherer Guntram Suske Paul Thornalley Csabo Szabo Mark Yorek

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