Targeting intracellular arginine / asymmetric dimethylarginine (ADMA).

Transcription

1 Targeting intracellular arginine / asymmetric dimethylarginine (ADMA). From bench to practice: Novel anti-atherogenic strategies to improve endothelial function Rainer H. Böger, M.D. Institute of Clinical Pharmacology and Toxicology Center of Experimental Medicine

2 Declaration of interest: I have been named as inventor on patent appliations relating to analytical methods for analyzing ADMA and related compounds. I receive royalties from such patent licenses.

3 The endothelial L-arginine / NO Pathway CAT L-arginine NO-Synthase L-citrulline NO Vasodilation Anti-inflammatory effects Anti-proliferatory effects Anti-thrombogenic effects

4 Lancet 1992; 339: Dimethylarginines in human plasma (ADMA+SDMA): Healthy (n = 6) End-stage renal failure (n = 9) 1.15 ± 0.13 µmol/l 8.70 ± 0.70 µmol/l

5 Chemical Structures of L-Arginine and Methylarginines CH 3 CH 3 CH 3 HN NH 2 HN NH HN N CH 3 H C 3 N NH C C C C NH NH NH NH H 2 N C O H 2 N C O H 2 N C O H 2 N C O OH OH OH OH L-arginine N G -monomethyl- L-arginine (L-NMMA) N G, N G -dimethyl- L-arginine (ADMA) N G, N G`-dimethyl- L-arginine (SDMA) NOS substrate NOS inhibitor NOS inhibitor not a NOS inhibitor

6 ADMA and SDMA modulate endothelial NO production CAT SDMA ADMA L-arginine NO-Synthase L-citrulline NO Vasodilation Anti-inflammatory effects Anti-proliferatory effects Anti-thrombogenic effects

7 40 30 Formation of 15 NO 2 [nmol / µg protein] from [guanidino- 15 N 2 ]-L-arginine ADMA inhibits the conversion of [ 15 N 2 ]-L-arginine to NO in vitro * * * * * 0 Control * -3 ADMA [log M] Böger et al.; Circ. Res. 2000; 87:

8 Flow-induced vasodilation [%] ADMA plasma concentration inversely correlates with endothelium-dependent vasodilation R = p < ADMA [µmol/l] Böger et al., Circulation 1998, 98:

9 ADMA NO is is an a anti-atherogenic pro-atherogenic molecule LDL oxidation vasodilation platelet aggregation ADMA NO O 2 superoxide radical elaboration smooth muscle cell proliferation monocyte adhesion

10 Effects of systemic ADMA infusion in healthy humans Achan et al., Arterioscler. Thromb. Vasc. Biol. 2003; 23: Kielstein et al., Circulation 2004, 109:

11 ADMA regulates NO production and vascular function Cardounel et al., J. Biol. Chem. 2007; 282:

12 ADMA: metabolism and (patho-)physiology methionine L-arginine S-adenosyl-methionine N-methyltransferase(s) -CH 3 S-adenosyl-homocysteine L-arginine CH 3 CH 3 homocysteine proteolysis L-arginine ADMA NO synthase DDAH L-citrulline urine endothelial dysfunction R.H. Böger; Cardiovasc. Res. 2003; 59:

13 % change NOS activity % change Effects of DDAH overexpression in mice Increased DDAH activity leads to reduced ADMA levels and reduced systemic vascular resistance * * increased urinary nitrate excretion 0 20 SKM Cardiac Aorta HR CO MAP SVR Dayoub et al., Circulation 2003; 108:

14 Disruption of DDAH-1 impairs vascular function in mice Heterozygous knockout of DDAH-1 leads to elevated ADMA plasma level (by some 20%), reduced DDAH activity in kidney and liver, and increased blood pressure with compensatory increase in heart rate. impaired endothelium-dependent relaxation ex vivo Leiper et al.; Nat. Med. 2007; 13:

15 Endothelial DDAH-1 account for the major portion of total DDAH activity Homozygous knockout of DDAH-1 leads to Endothelial-specific knockout of DDAH-1 leads to Hu et al.; ATVB 2011; 31: Hu et al.; Circulation 2009; 120:

16 ADMA: metabolism and (patho-)physiology methionine L-arginine S-adenosyl-methionine N-methyltransferase(s) -CH 3 S-adenosyl-homocysteine L-arginine CH 3 CH 3 homocysteine proteolysis L-arginine ADMA NO synthase DDAH L-citrulline R.H. Böger; Cardiovasc. Res. 2003; 59: urine endothelial dysfunction? cardiovascular disease

17 ADMA is a predictor of total mortality in patients with end-stage renal failure All cause mortality ADMA percentiles Cumulative survival.8.7 < 50 th (<2.52 µmol/l).6 50 th -75 th ( µmol/l) > 75 th (>3.85 µmol/l) Time (months) Zoccali et al.; Lancet 2001; 358:

18 1,874 patients with stable coronary artery disease Follow-up 2.6 ± 1.2 years Schnabel et al.; Circ. Res. 2005; 97: e53-59

19 ADMA: A predictor of mortality in the Framingham Offspring Cohort 3,320 study participants from the general population in Framingham, MA Total mortality HR = 1.21 ( ) per SD increment (0.13 µmol/l) P = Multivariate model adjusted for established CV risk factors included in the FRS plus BNP, renin, Hcys, CRP, urinary albumin excretion. Böger et al. Circulation 2009

20 Genome-wide association study of ADMA reveals DDAH-1 as the most important regulatory gene for ADMA in humans Genome-wide association for ADMA (Framingham Heart Study, Gutenberg Health Study, KORA MONICA Study Ddah1

21 Upregulation of DDAH-1 protects from atherosclerotic vascular injury Control mice ADMA = 0.88 µm DDAH-1 tg mice ADMA = 0.45 µm Jacobi,, Böger. Am J Pathol 2010

22 Septic shock is correlated with ADMA levels ADMA was elevated more strongly in patients who had greater vasoconstrictor infusion requirements O`Riordan et al.; Crit. Care 2006; 10: R139 RH Böger; Crit. Care 2006; 10: 169

23 Targeting intracellular arginine / asymmetric dimethylarginine (ADMA) Summary Numerous epidemiological studies have provided evidence for a statistical association between ADMA and cardiovascular disease. Pathophysiological evidence suggests that ADMA may exert its effects by interfering with NO production in the endothelium, resulting in endothelial dysfunction and advanced atherosclerosis. Prospective clinical trials have shown that elevated ADMA predicts major adverse cardiovascular events and mortality throughout the cardiovascular continuum. DDAH-1 appears to be the most prominent regulator of endogenous ADMA. DDAH-1 might thus be a novel target for pharmacotherapeutic intervention in cardiovascular diseases.

24 Acknowledgments University Medical Center Hamburg-Eppendorf Edzard Schwedhelm Nicole Lüneburg Maike Anderssohn Doro Atzler Anna Steenpaß Mariola Kastner Sandra Maak Daniel Appel Ghainsom Kom Thomas Eschenhagen Karsten Sydow, Kardiologie Thomas Meinertz, Kardiologie Thomas Standl, Anästhesiologie Stanford University John P. Cooke Phil S. Tsao Patrick S. Lin Instituto die Fisiologia, Reggio, IT Carmine Zoccali University of Iowa Steven R. Lentz University of Ulm Wolfgang Koenig University of Erlangen Renke Maas Johannes Jacobi Boston University Vasan S. Ramachandran University of Minnesota Yingjie Chen