title: Enhancing eNOS activity with simultaneous inhibition of IKKβ restores vascular function in Ins2(Akita+/-) type-1 diabetic mice.
abstract: The balance of nitric oxide (NO) versus superoxide generation has a major role in the initiation and progression of endothelial dysfunction. Under conditions of high glucose, endothelial nitric oxide synthase (eNOS) functions as a chief source of superoxide rather than NO. In order to improve NO bioavailability within the vessel wall in type-1 diabetes, we investigated treatment strategies that improve eNOS phosphorylation and NO-dependent vasorelaxation. We evaluated methods to increase the eNOS activity by (1) feeding Ins2(Akita) spontaneously diabetic (type-1) mice with l-arginine in the presence of sepiapterin, a precursor of tetrahydrobiopterin; (2) preventing eNOS/NO deregulation by the inclusion of inhibitor kappa B kinase beta (IKKβ) inhibitor, salsalate, in the diet regimen in combination with l-arginine and sepiapterin; and (3) independently increasing eNOS expression to improve eNOS activity and associated NO production through generating Ins2(Akita) diabetic mice that overexpress human eNOS predominantly in vascular endothelial cells. Our results clearly demonstrated that diet supplementation with l-arginine, sepiapterin along with salsalate improved phosphorylation of eNOS and enhanced vasorelaxation of thoracic/abdominal aorta in type-1 diabetic mice. More interestingly, despite the overexpression of eNOS, the in-house generated transgenic eNOS-GFP (TgeNOS-GFP)-Ins2(Akita) cross mice showed an unanticipated effect of reduced eNOS phosphorylation and enhanced superoxide production. Our results demonstrate that enhancement of endogenous eNOS activity by nutritional modulation is more beneficial than increasing the endogenous expression of eNOS by gene therapy modalities.
authors.affiliation: Department of Pathology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
authors.forename: Manickam
authors.initials: M
authors.lastname: Krishnan
authors.affiliation: Department of Pathology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
authors.forename: Preethi
authors.initials: P
authors.lastname: Janardhanan
authors.affiliation: Department of Biochemistry, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
authors.forename: Linda
authors.initials: L
authors.lastname: Roman
authors.affiliation: Department of Pathology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Reddick
authors.affiliation: Department of Pathology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
authors.forename: Mohan
authors.initials: M
authors.lastname: Natarajan
authors.affiliation: Department of Cell Biology and Genetics, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Rien
authors.initials: R
authors.lastname: van Haperen
authors.affiliation: Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
authors.forename: Samy L
authors.initials: SL
authors.lastname: Habib
authors.affiliation: Department of Cell Biology and Genetics, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Rini
authors.initials: R
authors.lastname: de Crom
authors.affiliation: Department of Pathology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
authors.forename: Sumathy
authors.initials: S
authors.lastname: Mohan
mesh_terms: D000818:Animals; D001011:Aorta / Q000166:cytology / Q000378:metabolism / Q000503:physiopathology; D001120:Arginine / Q000378:metabolism / Q000627:therapeutic use; D002417:Cattle; D002478:Cells, Cultured; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control*; D019587:Dietary Supplements; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism* / Q000503:physiopathology; D005260:Female; D006579:Heterozygote; D006801:Humans; D007004:Hypoglycemic Agents / Q000378:metabolism / Q000627:therapeutic use*; D007328:Insulin / Q000235:genetics / Q000378:metabolism; D008297:Male; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D052250:Nitric Oxide Synthase Type III / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000378:metabolism / Q000627:therapeutic use*; D011499:Protein Processing, Post-Translational; D011622:Pterins / Q000378:metabolism / Q000627:therapeutic use; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D012459:Salicylates / Q000378:metabolism / Q000627:therapeutic use; D014886:Weaning
chemical_list: D007004:Hypoglycemic Agents; C561967:Ins2 protein, mouse; D007328:Insulin; D047428:Protein Kinase Inhibitors; D011622:Pterins; D011993:Recombinant Fusion Proteins; D012459:Salicylates; D001120:Arginine; C016727:sepiapterin; D052250:Nitric Oxide Synthase Type III; C014182:salicylsalicylic acid