Enhanced activation of NAD(P)H: quinone oxidoreductase 1 attenuates spontaneous hypertension by improvement of endothelial nitric oxide synthase coupling via tumor suppressor kinase liver kinase B1/adenosine 5'-monophosphate-activated protein kinase-mediated guanosine 5'-triphosphate cyclohydrolase 1 preservation.
OBJECTIVE
Guanosine 5'-triphosphate cyclohydrolase-1 (GTPCH-1) is a rate-limiting enzyme in de-novo synthesis of tetrahydrobiopterin (BH4), an essential cofactor for endothelial nitric oxide synthase (eNOS) coupling. Adenosine 5'-monophosphate-activated protein kinase (AMPK) is crucial for GTPCH-1 preservation, and tumor suppressor kinase liver kinase B1 (LKB1), an upstream kinase of AMPK, is activated by NAD-dependent class III histone deacetylase sirtuin 1 (SIRT1)-mediated deacetylation. β-Lapachone has been shown to increase cellular NAD/NADH ratio via
quinone oxidoreductase 1 (NQO1) activation. In this study, we have evaluated whether β-lapachone-induced NQO1 activation modulates blood pressure (BP) through preservation of GTPCH-1 in a hypertensive animal model.


RESULTS
Spontaneously hypertensive rats (SHRs), primary aortic endothelial cells, and endothelial cell line were used to investigate the hypotensive effect of β-lapachone and its action mechanism. β-Lapachone treatment dramatically lowered BP and vascular tension in SHRs and induced eNOS activation in endothelial cells. Consistent with these effects, β-lapachone treatment also elevated levels of both aortic cGMP and plasma nitric oxide in SHRs. Meanwhile, β-lapachone-treated SHRs showed significantly increased levels of aortic NAD, LKB1 deacetylation, and AMPK Thr phosphorylation followed by increased GTPCH-1 and tetrahydrobiopterin/dihydrobiopterin ratio. In-vitro study revealed that AMPK inhibition by overexpression of dominant-negative AMPK nearly abolished GTPCH-1 protein conservation. Enhanced LKB1 deacetylation and AMPK activation were also elicited by β-lapachone in endothelial cells. However, inhibition of LKB1 deacetylation by blocking of NQO1 or SIRT1 blunted AMPK activation by β-lapachone.


CONCLUSIONS
This is the first study demonstrating that eNOS coupling can be regulated by NQO1 activation via LKB1/AMPK/GTPCH-1 modulation, which is possibly correlated with relieving hypertension. These findings provide strong evidence to suggest that NQO1 might be a new therapeutic target for hypertension.
aLaboratory Animal Center, Korea Research Institute of Bioscience and Biotechnology, Yuseong-gu, Daejeon bKorea Bioactive Natural Material Bank, College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul cDiabetes and Metabolic Disease Research Center, Lee Gil Ya Cancer & Diabetes Institute, Gachon University of Medicine, Incheon dKT&G Life Sciences Corporation/R&D Center, Suwon eHormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju fDepartment of Internal Medicine, Kyungpook National University School of Medicine, Daegu, South Korea.
Yong-Hoon
YH
Kim
Jung Hwan
JH
Hwang
Kyung-Shim
KS
Kim
Jung-Ran
JR
Noh
Gil-Tae
GT
Gang
Won Keun
WK
Oh
Kyeong-Hoon
KH
Jeong
Tae Hwan
TH
Kwak
Hueng-Sik
HS
Choi
In-Kyu
IK
Lee
Chul-Ho
CH
Lee
D055372:AMP-Activated Protein Kinases / Q000378:metabolism*; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology; D001011:Aorta / Q000187:drug effects / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D002460:Cell Line; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000187:drug effects / Q000201:enzymology; D004789:Enzyme Activation / Q000187:drug effects; D006136:GTP Cyclohydrolase / Q000378:metabolism*; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000201:enzymology* / Q000503:physiopathology*; D008297:Male; D051379:Mice; D009243:NAD / Q000378:metabolism; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009285:Naphthoquinones / Q000494:pharmacology; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D051381:Rats; D011918:Rats, Inbred SHR; D056564:Sirtuin 1 / Q000037:antagonists & inhibitors / Q000378:metabolism; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology
D000959:Antihypertensive Agents; D009285:Naphthoquinones; D009243:NAD; C014638:beta-lapachone; D052250:Nitric Oxide Synthase Type III; D016660:NAD(P)H Dehydrogenase (Quinone); D017346:Protein Serine-Threonine Kinases; D055372:AMP-Activated Protein Kinases; D056564:Sirtuin 1; D006136:GTP Cyclohydrolase