Direct angiotensin II type 2 receptor stimulation acts anti-inflammatory through epoxyeicosatrienoic acid and inhibition of nuclear factor kappaB.
Angiotensin II type 2 (AT(2)) receptors can be regarded as an endogenous repair system, because the AT(2) receptor is upregulated in tissue damage and mediates tissue protection. A potential therapeutic use of this system has only recently come within reach through synthesis of the first selective, orally active, nonpeptide AT(2) receptor agonist, compound 21 (C21; dissociation constant for AT(2) receptor: 0.4 nM; dissociation constant for angiotensin II type 1 receptor: >10,000 nM). This study tested AT(2) receptor stimulation with C21 as a potential future therapeutic approach for the inhibition of proinflammatory cytokines and of nuclear factor kappaB. C21 dose-dependently (1 nM to 1 micromol/L) reduced tumor necrosis factor-alpha-induced interleukin 6 levels in primary human and murine dermal fibroblasts. AT(2) receptor specificity was controlled for by inhibition with the AT(2) receptor antagonist PD123319 and by the absence of effects in AT(2) receptor-deficient cells. AT(2) receptor-coupled signaling leading to reduced interleukin 6 levels involved inhibition of nuclear factor kappaB, activation of protein phosphatases, and synthesis of epoxyeicosatrienoic acid. Inhibition of interleukin 6 promoter activity by C21 was comparable in strength to inhibition by hydrocortisone. C21 also reduced monocyte chemoattractant protein 1 and tumor necrosis factor-alpha in vitro and in bleomycin-induced toxic cutaneous inflammation in vivo. This study is the first to show the anti-inflammatory effects of direct AT(2) receptor stimulation in vitro and in vivo by the orally active, nonpeptide AT(2) receptor agonist C21. These data suggest that pharmacological AT(2) receptor stimulation may be an orally applicable future therapeutic approach in pathological settings requiring the reduction of interleukin 6 or inhibition of nuclear factor kappaB.
Center for Cardiovascular Research, Charité-Universitätsmedizin Berlin, Hessische Str 3-4, 10115 Berlin, Germany. ulrike.steckelings@charite.de
Franziska
F
Rompe
Metin
M
Artuc
Anders
A
Hallberg
Mathias
M
Alterman
Katja
K
Ströder
Christa
C
Thöne-Reineke
Anne
A
Reichenbach
Jens
J
Schacherl
Björn
B
Dahlöf
Michael
M
Bader
Natalia
N
Alenina
Markus
M
Schwaninger
Torsten
T
Zuberbier
Heiko
H
Funke-Kaiser
Cosima
C
Schmidt
Wolf-Hagen
WH
Schunck
Thomas
T
Unger
U Muscha
UM
Steckelings
D015126:8,11,14-Eicosatrienoic Acid / Q000378:metabolism*; D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000235:genetics / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005347:Fibroblasts / Q000166:cytology; D006801:Humans; D007249:Inflammation / Q000378:metabolism*; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D044139:Receptor, Angiotensin, Type 2 / Q000819:agonists* / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D013449:Sulfonamides / Q000494:pharmacology; D013876:Thiophenes / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism
D018932:Chemokine CCL2; D015850:Interleukin-6; C494557:N-butyloxycarbonyl-3-(4-imidazol-1-ylmethylphenyl)-5-isobutylthiophene-2-sulfonamide; D016328:NF-kappa B; D012333:RNA, Messenger; D044139:Receptor, Angiotensin, Type 2; D013449:Sulfonamides; D013876:Thiophenes; D014409:Tumor Necrosis Factor-alpha; D015126:8,11,14-Eicosatrienoic Acid