title: Changes in cultured endothelial cell glycosaminoglycans under hyperglycemic conditions and the effect of insulin and heparin.
abstract: BACKGROUND
  Heparan sulfate proteoglycans (HSPGs) contain glycosaminoglycan (GAG) chains made primarily of heparan sulfate (HS). Hyperglycemia in diabetes leads to endothelial injury and nephropathy, retinopathy and atherosclerosis. Decreased HSPG may contribute to diabetic endothelial injury. Decreased tissue HS in diabetes has been reported, however, endothelial HS changes are poorly studied.
  
  
  OBJECTIVE
  To determine total GAGs, including HS, in endothelium under hyperglycemic conditions and the protective effect of insulin and heparin.
  
  
  METHODS
  Confluent primary porcine aortic endothelial cells (PAECs) were divided into control, glucose (30 mM), insulin (0.01 unit/ml) and glucose plus insulin treatment groups for 24, 48 and 72 hours. Additionally, PAECs were treated with glucose, heparin (0.5 microg/ml) and glucose plus heparin for 72 hours. GAGs were isolated from cells and medium. GAG concentrations were determined by the carbazole assay and agarose gel electrophoresis.
  
  
  RESULTS
  GAGs were significantly increased only in control and glucose plus insulin groups at 72 versus 24 hours. Glucose decreased cell GAGs and increased medium GAGs, and insulin alone decreased cell GAGs at all times compared to control. In the glucose plus insulin group, cell GAGs were less than control at 24 hours, and greater than glucose or insulin alone at 48 and 72 hours while GAGs in medium were greater than control at all times and glucose at 72 hours. Heparin increased GAGs in glucose treated cells and medium.
  
  
  CONCLUSIONS
  High glucose and insulin alone reduces endothelial GAGs. In hyperglycemic conditions, heparin or insulin preserves GAGs which may protect cells from injury. Insulin is an effective diabetic therapy since it not only lowers blood glucose, but also protects endothelium.
authors.affiliation: Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B4, Canada. juh884@mail.usask.ca
authors.forename: Juying
authors.initials: J
authors.lastname: Han
authors.forename: Fuming
authors.initials: F
authors.lastname: Zhang
authors.forename: Jin
authors.initials: J
authors.lastname: Xie
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Linhardt
authors.forename: Linda M
authors.initials: LM
authors.lastname: Hiebert
mesh_terms: D000818:Animals; D002478:Cells, Cultured / Q000187:drug effects / Q000378:metabolism; D004347:Drug Interactions; D004587:Electrophoresis, Agar Gel; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism; D005947:Glucose / Q000494:pharmacology*; D006025:Glycosaminoglycans / Q000032:analysis / Q000378:metabolism*; D019812:Heparan Sulfate Proteoglycans / Q000032:analysis / Q000378:metabolism; D006493:Heparin / Q000494:pharmacology*; D006497:Heparan Sulfate / Q000032:analysis / Q000378:metabolism; D007328:Insulin / Q000494:pharmacology*; D034421:Sus scrofa; D013552:Swine; D053667:Syndecans / Q000032:analysis / Q000378:metabolism; D013997:Time Factors
chemical_list: D005947:Glucose; D006025:Glycosaminoglycans; D019812:Heparan Sulfate Proteoglycans; D006493:Heparin; D006497:Heparan Sulfate; D007328:Insulin; D053667:Syndecans; C071927:perlecan
references.citation: Kidney Int. 2000 Jun;57(6):2492-501
references.pmid: 10844618
references.citation: Exp Nephrol. 1997 May-Jun;5(3):180-8
references.pmid: 9208276
references.citation: J Vasc Res. 2001 Sep-Oct;38(5):415-22
references.pmid: 11561143
references.citation: J Biol Chem. 1987 Apr 5;262(10):4708-16
references.pmid: 2951371
references.citation: Annu Rev Cell Biol. 1992;8:365-93
references.pmid: 1335744
references.citation: Annu Rev Biochem. 1991;60:443-75
references.pmid: 1883201
references.citation: Diabetologia. 1989 Apr;32(4):219-26
references.pmid: 2668076
references.citation: J Surg Res. 1980 Jun;28(6):556-62
references.pmid: 6448319
references.citation: Biochim Biophys Acta. 2004 Apr 7;1672(1):36-45
references.pmid: 15056491
references.citation: Diabetologia. 1992 Feb;35(2):183-6
references.pmid: 1547925
references.citation: Kidney Int. 1995 Nov;48(5):1508-16
references.pmid: 8544408
references.citation: J Biol Chem. 2000 Jan 14;275(2):1463-70
references.pmid: 10625699
references.citation: Diabetes. 1983 Apr;32(4):337-42
references.pmid: 6219905
references.citation: Kidney Int. 2006 Dec;70(12):2100-8
references.pmid: 17051139
references.citation: Experientia. 1993 May 15;49(5):447-55
references.pmid: 8500599
references.citation: Biochem Soc Trans. 1997 Feb;25(1):220-4
references.pmid: 9056874
references.citation: Am J Pathol. 1981 May;103(2):271-82
references.pmid: 7195151
references.citation: Cardiovasc Diabetol. 2005 Aug 09;4:12
references.pmid: 16086844
references.citation: Arch Biochem Biophys. 1991 Mar;285(2):205-10
references.pmid: 1897927
references.citation: Experientia. 1995 Sep 29;51(9-10):863-72
references.pmid: 7556568
references.citation: Life Sci. 1984 Dec 24;35(26):2613-20
references.pmid: 6239964
references.citation: Arch Biochem Biophys. 1995 Apr 20;318(2):286-94
references.pmid: 7733656
references.citation: J Cell Physiol. 1989 Aug;140(2):305-10
references.pmid: 2745565
references.citation: J Lab Clin Med. 1990 Apr;115(4):422-32
references.pmid: 1691256
references.citation: Isr Med Assoc J. 2002 Nov;4(11):996-1002
references.pmid: 12489489
references.citation: N Engl J Med. 1983 Oct 27;309(17):1001-9
references.pmid: 6225948
references.citation: J Am Soc Nephrol. 1994 Mar;4(9):1683-9
references.pmid: 8011978
references.citation: Int J Biochem Cell Biol. 2000 Feb;32(2):115-20
references.pmid: 10687947
references.citation: Diabetes. 1982 May;31(5 Pt 1):418-25
references.pmid: 7152134
references.citation: Diabetologia. 1994 Mar;37(3):313-20
references.pmid: 8174847
references.citation: Exp Biol Med (Maywood). 2007 Jul;232(7):927-34
references.pmid: 17609509
references.citation: Semin Thromb Hemost. 1991;17 Suppl 1:47-56
references.pmid: 2068571
references.citation: Am J Cardiol. 1999 Jul 8;84(1A):21J-24J
references.pmid: 10418854
references.citation: Circulation. 2000 Apr 4;101(13):1539-45
references.pmid: 10747347
references.citation: J Biol Chem. 1983 Oct 10;258(19):11672-7
references.pmid: 6225778
references.citation: Arterioscler Thromb Vasc Biol. 2004 May;24(5):858-63
references.pmid: 15031130
references.citation: Diabetologia. 1993 Apr;36(4):316-22
references.pmid: 8477876
references.citation: Kidney Int. 1992 Aug;42(2):285-91
references.pmid: 1328749
references.citation: Eur J Nutr. 2006 Oct;45(7):369-75
references.pmid: 16810465
references.citation: Biochemistry. 2006 May 9;45(18):5703-11
references.pmid: 16669614
references.citation: J Clin Invest. 1997 Dec 1;100(11 Suppl):S67-75
references.pmid: 9413405
references.citation: Am J Med. 1988 Nov 28;85(5A):113-8
references.pmid: 3057888