nNOS activation is involved in insulin-mediated CV effects in the NTS
1. nNOS activation is involved in insulin-mediated cardiovascular effects in the nucleus tractus solitarii of rats Chiang H.T. et al. 2009 Neuroscience I.F. = 3.556
2. Introduction › › › Generalization - Receptor tyrosine kinase (RTK) - Activation : insulin binding Location in CNS - Cerebellum - Olfactory bulb - Hippocampus - Hypothalamus - Cerebral cortex - Nucleus tractus solitarius CVS function - Heart rate - Arterial blood pressure 1 Unger J. W. et al. 1991. Prog Neurobiol. 36: 343-362; 2 Adamo M. et al. 1989. Mol Neurobiol . 3:71-100. The insulin receptor in the central nervous system (CNS) 1,2 Insulin receptor Generalization CVS function Location in CNS
3.
4. Introduction › › › The role of nucleus tractus solitarius (NTS) on cardiovascular function 1 Autonomic control of the cardiovascular system Arterial baroreceptor Chemoreceptor Cardiopulmonary receptor Visceral receptor Nucleus tractus solitarius Primary integrative center 1 Dampney R. A. 1994. Physiol Rev. 74: 323-363 Sympathetic nerve activity Heart rate (HR) Blood pressure (BP)
5.
6.
7. Introduction › › › The relationship between insulin-PI3K-Akt pathway and nNOS-derived NO in NTS 1,2 1 Huang H. N. et al. 2004. Circulation. 110: 2476-2483.; 2 Bredt D. S. et al. 1990. Nature. 347: 768-770 Control Control The relationship between insulin-PI3K-Akt signaling pathway and nNOS-derived NO in NTS is unclear
8. Hypothesis › › › nNOS phosphorylation is induced by insulin injection in the NTS via PI3K-Akt signaling pathway 1 nNOS is downstream factor in insulin-PI3K-Akt signaling pathway 2 The activation of nNOS-derived NO by insulin-PI3K-Akt signaling pathway participates in central cardiovascular regulation 3
9.
10.
11.
12.
13.
14.
15. Inhibitory effect of the nNOS inhibitor on insulin-mediated cardiovascular effect 1-5 1 Huang H. N. et al. 2004. Circulation. 110: 2476-2483; 2 Tseng C. J. et al. 1996. Hypertension. 2 7: 36-42; 3 Lo W. C. et al. 2004. Hypertension. 2 2: 36-42; 4 Ollerstam A. et al. 1997. J Clin Invest. 99 : 2212-2218; 5 Babu B. R. and Griffith O. W. 1998. J Biol Chem. 273: 8882-8889. Results and discussion › › › Insulin-induced insulin receptor activity 7-NI Vinyl-L-NIO nNOS-dependent nitric oxide Nucleus tractus solitarius function regulate Sympathetic nervous activity Baroreceptor reflex modulate Cardiovascular function
16.
17. nNOS phosphorylation at ser 1416 induced by insulin injection in the NTS 1-3 1 Huang H. N. et al. 2004. Circulation. 110: 2476-2483 2 Yuan Z.R. et al. 2004. Brain research. 1008: 1-10 3 Vlahos C. J. et al. 1994. J Biol Chem. 269: 5241-5248 Results and discussion › › › Insulin-induced insulin receptor activity PI3K-Akt signaling pathway LY294002 nNOS phosphorylation at Ser 1416
18.
19.
20.
21.
22. Summary › › › Insulin receptor (IR) Insulin nNOS activation is involved in insulin-mediated cardiovascular effect in the NTS P P P P IR substrate IR substrate PI3K P PI3K P PDK P PDK P Insulin-Pi3K-Akt pathway PIP 2 P P PIP 2 P P PIP 3 P P P PIP 3 P P P Ser 1416 P nNOS P nNOS-derived NO nNOS phosphorylation is induced by insulin injection in the NTS via PI3K-Akt signaling pathway 1 Akt P P Akt P P
23. Summary › › › nNOS activation is involved in insulin-mediated cardiovascular effect in the NTS nNOS is downstream factor in insulin-PI3K-Akt signaling pathway 2 Insulin receptor (IR) Insulin P P P P IR substrate IR substrate PI3K P PI3K P PDK P PDK P Insulin-Pi3K-Akt pathway PIP 2 P P PIP 2 P P PIP 3 P P P PIP 3 P P P Ser 1416 P nNOS P nNOS-derived NO Akt P P Akt P P
24. Summary › › › nNOS activation is involved in insulin-mediated cardiovascular effect in the NTS Hypotension Bradycardia ↓ Heart rate ↓ Arterial pressure The activation of nNOS-derived NO by insulin-PI3K-Akt signaling pathway participates in central cardiovascular regulation 3 Insulin receptor (IR) Insulin P P P P IR substrate IR substrate PI3K P PI3K P PDK P PDK P Insulin-Pi3K-Akt pathway PIP 2 P P PIP 2 P P PIP 3 P P P PIP 3 P P P Ser 1416 P nNOS P nNOS-derived NO Akt P P Akt P P
25. Summary › › › nNOS activation is involved in insulin-mediated cardiovascular effect in the NTS Hypertension Tachycardia ↑ Heart rate ↑ Arterial pressure Insulin receptor (IR) Insulin P P P P IR substrate IR substrate PI3K P PI3K P PDK P PDK P Insulin-Pi3K-Akt pathway PIP 2 P P PIP 2 P P PIP 3 P P P PIP 3 P P P Ser 1416 P nNOS P nNOS-derived NO Akt P P Akt P P The nNOS inhibitor and PI3K inhibitor reverse the cardiovascular responses of insulin 4 Vinyl-L-NIO 7-NI LY294002 LY294002
33. 1 Ravinder K. et al. 2006. GI Motility online. doi:10.1038/gimo14 Backup › › › The role of NTS on swallowing 1 Mechanism Sensory signal Dorsal vagal nucleus Nucleus ambiguus Nucleus tractus solitarius (NTS) Lower esophageal sphincter (LES) Crural diaphragm Relaxation Contraction
34.
35.
36. Backup › › › nNOS phosphorylation 1-4 1 Song T. et al. 2004. FEBS Letters . 570 :133–137 2 Rameau G. A. et al. 2004. J Biol Chem . 279(14): 14307-143014 3 Finocchietto P . et al. 2008. PLoS ONE. 3(3): e1749. doi:10.1371/journal.pone.0001749 4 Song T. et al. 2004. FEBS Letters . 570 :133–137 Enzyme Phosphorylate site of nNOS Effect on nNOS Ref. CaM-K I Ser 741 Inhibition 1 Cam-K II Ser 847 Inhibition 2 Akt Ser 1412 Activation 3 Akt Ser 1416 Activation 4
38. 1 Herring N. and Paterson D. J. 2001. J Physiol . 535: 507-18 2 Paton J. F. R. et al. 2002. TRENDS in Neuroscience . 25(12): 626-631 Backup › › › The role of nNOS-derived NO on heart rate 1, 2 (via G i protein )
39. 1 Toda N. and Ayajiki K. 2010. Alcohol and Alcoholism . 45 (4): 347-355 Backup › › › The role of nNOS-derived NO on blood pressure 1
40. Abbreviation: PIP 2 = Phosphatidylinositol (PI) 4,5-bisphosphate, PIP 3 = PI 3,4,5-triphosphate Structure and classification BackUp › › › Phosphatidylinositol 3-kinase (PI3K) 1,2,3 PIP 2 PIP 3 PI3K - Lipase kinase 1 Ito K. et al. 2007. Perspectives in Pharmacology . 321 (1): 1-8 2 Oudit G. Y. and Penninger J. M. 2009. Cardiovascular Research . 82: 250–260 3 Bader A. G. et al. 2005. Nature Reviews Cancer . 5(12): 921-929 Catalytic subunit Regulatory adaptor subunit SH2/SH3 domain
41.
42. Backup › › › 3-phosphoinositide dependent protein kinase (PDK) 1 1 Reuben J. et al. 2006. Nature. 441: 424-430 PDK1 PDK2 Akt Thr 308 Akt Ser 473 PDK
NTS is located along the length of the medulla (with a small portion in the lower pons ) Chemoreceptor มี 2 ประเภท คือ peripheral chemoreceptor (carotic กับ aortic body) และ central chemoreceptor (medulla) Baroreceptor อยู่ที่ carotic sinus และ aortic arch Inotrophy : contractility; chronotrophy : heart rate and Inotrophy : conduction velocity
7-NI interacts competitively at the substrate binding site and the co-factor tetrahydrobiopterin (BH4) in the NOS enzyme
Pacemaker cell ส่วนใหญเป็น sinoatrial (SA) node Muscarinic type 2 acetylcholine receptor ที่กระตุ้นการทำงานของ G i protein
Pacemaker cell ส่วนใหญเป็น sinoatrial (SA) node Muscarinic type 2 acetylcholine receptor ที่กระตุ้นการทำงานของ G i protein
The p85 subunit of PI3K contains SH2 and SH3 domain The SH2 domain binds phosphotyrosine residues
LY294002 is a morpholine derivative of quercetin (flavonoid) LY294002 is a cell-permeable compound LY294002 acts as a potent and selective inhibitor of PI3K
7-NI interacts competitively at the substrate binding site and the co-factor tetrahydrobiopterin (BH4) in the NOS enzyme