title: Role of HSP-90 for increased nNOS-mediated vasodilation in mesenteric arteries in portal hypertension.
abstract: OBJECTIVE
  To explore the role of heat shock protein-90 (HSP-90) for nitrergic vasorelaxation in the splanchnic circulation in rats with and without portal hypertension.
  
  
  METHODS
  Neuronal nitric oxide synthase (nNOS) and HSP-90 were analyzed by immunofluorescence, western blotting and co-immunoprecipitation in the mesenteric vasculature and isolated nerves of portal-vein-ligated (PVL) rats and sham operated rats. In vitro perfused de-endothelialized mesenteric arterial vasculature was preconstricted with norepinephrine (EC(80)) and tested for nNOS-mediated vasorelaxation by periarterial nerve stimulation (PNS, 2-12 Hz, 45V) before and after incubation with geldanamycin (specific inhibitor of HSP-90 signalling, 3 microg/mL) or L-NAME (non-specific NOS-blocker, 10(-4) mol/L).
  
  
  RESULTS
  nNOS and HSP-90 expression was significantly increased in mesenteric nerves from PVL as compared to sham rats. Moreover, nNOS and HSP-90 were visualized in mesenteric nerves by immunofluorescence and immunoprecipitation of nNOS co-immunoprecipitated HSP-90 in sham and PVL rats. PNS induced a frequency-dependent vasorelaxation which was more pronounced in PVL as compared to sham rats. L-NAME and geldanamycin markedly reduced nNOS-mediated vasorelaxation abrogating differences between the study groups. The effect of L-NAME and geldanamycin on nNOS-mediated vasorelaxation was significantly greater in PVL than in sham animals. However, no difference in magnitude of effect between L-NAME and geldanamycin was noted.
  
  
  CONCLUSIONS
  HSP-90 acts as a signalling mediator of nNOS-dependent nerve mediated vascular responses in mesenteric arteries, and the increased nitrergic vasorelaxation observed in portal hypertension is mediated largely by HSP-90.
authors.affiliation: Department of Internal Medicine I, University Medical Center, D-93042 Regensburg, Germany.
authors.forename: Lukas
authors.initials: L
authors.lastname: Moleda
authors.forename: Lars
authors.initials: L
authors.lastname: Jurzik
authors.forename: Matthias
authors.initials: M
authors.lastname: Froh
authors.forename: Erwin
authors.initials: E
authors.lastname: Gäbele
authors.forename: Claus
authors.initials: C
authors.lastname: Hellerbrand
authors.forename: Rainer H
authors.initials: RH
authors.lastname: Straub
authors.forename: Jürgen
authors.initials: J
authors.lastname: Schölmerich
authors.forename: Reiner
authors.initials: R
authors.lastname: Wiest
mesh_terms: D000818:Animals; D016227:Benzoquinones / Q000494:pharmacology; D015153:Blotting, Western; D018841:HSP90 Heat-Shock Proteins / Q000378:metabolism*; D006975:Hypertension, Portal / Q000378:metabolism / Q000473:pathology*; D047468:Immunoprecipitation; D047029:Lactams, Macrocyclic / Q000494:pharmacology; D008297:Male; D008638:Mesenteric Arteries / Q000473:pathology*; D008856:Microscopy, Fluorescence / Q000379:methods; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D052248:Nitric Oxide Synthase Type I / Q000378:metabolism*; D010477:Perfusion; D051381:Rats; D017207:Rats, Sprague-Dawley; D014664:Vasodilation
chemical_list: D016227:Benzoquinones; D018841:HSP90 Heat-Shock Proteins; D047029:Lactams, Macrocyclic; D052248:Nitric Oxide Synthase Type I; D019331:NG-Nitroarginine Methyl Ester; C001277:geldanamycin
references.citation: J Hepatol. 1998 Jun;28(6):1031-6
references.pmid: 9672180
references.citation: Semin Liver Dis. 1986 Nov;6(4):287-98
references.pmid: 3544222
references.citation: Science. 1995 Jun 2;268(5215):1362-5
references.pmid: 7761857
references.citation: J Hepatol. 2001 Oct;35(4):452-6
references.pmid: 11682028
references.citation: J Hypertens. 1995 Oct;13(10):1163-8
references.pmid: 8586808
references.citation: Circ Res. 2002 May 3;90(8):866-73
references.pmid: 11988487
references.citation: Hepatology. 2003 Dec;38(6):1508-15
references.pmid: 14647062
references.citation: Pharmacol Toxicol. 1993 Mar;72(3):194-8
references.pmid: 8100066
references.citation: Am J Physiol. 1993 Apr;264(4 Pt 2):R738-46
references.pmid: 7682793
references.citation: Biochem J. 2001 Apr 15;355(Pt 2):357-60
references.pmid: 11284722
references.citation: Clin Exp Pharmacol Physiol. 1995 Aug;22(8):506-11
references.pmid: 7586705
references.citation: Hepatol Res. 2007 Jan;37(1):58-67
references.pmid: 17300699
references.citation: Am J Physiol. 1999 Apr;276(4):G1043-51
references.pmid: 10198349
references.citation: Gastroenterology. 2001 Mar;120(4):975-83
references.pmid: 11231951
references.citation: J Biol Chem. 2004 Jul 16;279(29):30252-8
references.pmid: 15155759
references.citation: Cardiovasc Res. 1999 Aug 15;43(3):509-20
references.pmid: 10690323
references.citation: J Hepatol. 2005 Aug;43(2):258-65
references.pmid: 15963596
references.citation: J Hepatol. 1997 Sep;27(3):588-91
references.pmid: 9314140
references.citation: Cell. 1997 Jul 11;90(1):65-75
references.pmid: 9230303
references.citation: Annu Rev Pharmacol Toxicol. 1997;37:297-326
references.pmid: 9131255
references.citation: Proc Natl Acad Sci U S A. 1994 Aug 30;91(18):8324-8
references.pmid: 8078881
references.citation: Annu Rev Physiol. 1995;57:737-69
references.pmid: 7539995
references.citation: J Clin Gastroenterol. 2005 Apr;39(4 Suppl 2):S125-30
references.pmid: 15758647
references.citation: Nature. 1998 Apr 23;392(6678):821-4
references.pmid: 9580552
references.citation: Adv Protein Chem. 2001;59:157-86
references.pmid: 11868271
references.citation: Hepatology. 1988 Sep-Oct;8(5):1151-7
references.pmid: 2971015
references.citation: Hepatology. 1994 Dec;20(6):1615-21
references.pmid: 7527007
references.citation: Semin Liver Dis. 1999;19(4):411-26
references.pmid: 10643626
references.citation: FEBS Lett. 1997 Feb 10;403(1):40-4
references.pmid: 9038357
references.citation: J Biol Chem. 2002 Jun 7;277(23):20504-9
references.pmid: 11923316
references.citation: Am J Physiol. 1999 Aug;277(2):G463-8
references.pmid: 10444461
references.citation: Gastroenterology. 2003 Aug;125(2):522-31
references.pmid: 12891555
references.citation: Gastroenterology. 1992 Dec;103(6):1909-15
references.pmid: 1451984
references.citation: Am J Physiol Cell Physiol. 2001 Dec;281(6):C1819-24
references.pmid: 11698240
references.citation: J Clin Invest. 1999 Nov;104(9):1223-33
references.pmid: 10545521
references.citation: Am J Physiol Renal Physiol. 2000 Dec;279(6):F1110-5
references.pmid: 11097630
references.citation: J Biol Chem. 2000 Jun 9;275(23):17407-11
references.pmid: 10751385
references.citation: Hepatology. 2002 Feb;35(2):478-91
references.pmid: 11826425
references.citation: Br J Pharmacol. 1992 Jan;105(1):184-90
references.pmid: 1596680
references.citation: Gastroenterology. 1992 Jul;103(1):235-9
references.pmid: 1612331
references.citation: World J Gastroenterol. 2003 Nov;9(11):2544-7
references.pmid: 14606093
references.citation: Gastroenterology. 1995 Nov;109(5):1624-30
references.pmid: 7557147
references.citation: J Biol Chem. 1997 Sep 19;272(38):23843-50
references.pmid: 9295332
references.citation: J Biol Chem. 1999 Jan 15;274(3):1472-8
references.pmid: 9880522