D-glucose stimulation of L-arginine transport and nitric oxide synthesis results from activation of mitogen-activated protein kinases p42/44 and Smad2 requiring functional type II TGF-beta receptors in human umbilical vein endothelium.
Elevated extracellular D-glucose increases transforming growth factor beta1 (TGF-beta1) release from human umbilical vein endothelium (HUVEC). TGF-beta1, via TGF-beta receptors I (TbetaRI) and TbetaRII, activates Smad2 and mitogen-activated protein kinases p44 and p42 (p42/44(mapk)). We studied whether D-glucose-stimulation of L-arginine transport and nitric oxide synthesis involves TGF-beta1 in primary cultures of HUVEC. TGF-beta1 release was higher ( approximately 1.6-fold) in 25 mM (high) compared with 5 mM (normal) D-glucose. TGF-beta1 increases L-arginine transport (half maximal effect approximately 1.6 ng/ml) in normal D-glucose, but did not alter high D-glucose-increased L-arginine transport. TGF-beta1 and high D-glucose increased hCAT-1 mRNA expression ( approximately 8-fold) and maximal transport velocity (V(max)), L-[(3)H]citrulline formation from L-[(3)H]arginine (index of NO synthesis) and endothelial NO synthase (eNOS) protein abundance, but did not alter eNOS phosphorylation. TGF-beta1 and high D-glucose increased p42/44(mapk) and Smad2 phosphorylation, an effect blocked by PD-98059 (MEK1/2 inhibitor). However, TGF-beta1 and high D-glucose were ineffective in cells expressing a truncated, negative dominant TbetaRII. High D-glucose increases L-arginine transport and eNOS expression following TbetaRII activation by TGF-beta1 involving p42/44(mapk) and Smad2 in HUVEC. Thus, TGF-beta1 could play a crucial role under conditions of hyperglycemia, such as gestational diabetes mellitus, which is associated with fetal endothelial dysfunction.
Vásquez
Rodrigo
R
Cellular and Molecular Physiology Laboratory, Department of Obstetrics and Gynaecology, Medical Research Centre, School of Medicine, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile.
Farías
Marcelo
M
Vega
José Luis
JL
Martin
Rody San
RS
Vecchiola
Andrea
A
Casanello
Paola
P
Sobrevia
Luis
L
D000409:Alanine / Q000378:metabolism*; D019898:Autocrine Communication; D001692:Biological Transport; D027201:Cationic Amino Acid Transporter 1 / Q000096:biosynthesis / Q000235:genetics; D002478:Cells, Cultured; D002956:Citrulline / Q000378:metabolism; D042783:Endothelial Cells / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D004789:Enzyme Activation; D004790:Enzyme Induction; D005419:Flavonoids / Q000494:pharmacology; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009154:Mutation; D009569:Nitric Oxide / Q000096:biosynthesis*; D052250:Nitric Oxide Synthase Type III / Q000096:biosynthesis / Q000235:genetics; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D000077294:Receptor, Transforming Growth Factor-beta Type II; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D051899:Smad2 Protein / Q000378:metabolism*; D014161:Transduction, Genetic; D053773:Transforming Growth Factor beta1 / Q000378:metabolism*
D027201:Cationic Amino Acid Transporter 1; D005419:Flavonoids; D047428:Protein Kinase Inhibitors; D012333:RNA, Messenger; D018125:Receptors, Transforming Growth Factor beta; C420825:SLC7A1 protein, human; C497782:SMAD2 protein, human; D051899:Smad2 Protein; D053773:Transforming Growth Factor beta1; D002956:Citrulline; D009569:Nitric Oxide; C496314:NOS3 protein, human; D052250:Nitric Oxide Synthase Type III; D017346:Protein Serine-Threonine Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D000077294:Receptor, Transforming Growth Factor-beta Type II; D005947:Glucose; D000409:Alanine; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one