Divergent effects of corticotropin releasing hormone on endothelial cell nitric oxide synthase are associated with different expression of CRH type 1 and 2 receptors.
1. Endothelium is a target for an array of factors involved in inflammation. Endothelial cells express receptors for CRH, a neuropeptide produced during inflammation. We report both the concentration-dependent inhibitory effect of CRH upon cytokine-stimulated nitrite release by H5V murine endothelioma cells, and its stimulatory one in HUVEC cells. 2. Western blot analysis showed that CRH inhibits cytokine-stimulated iNOS protein in H5V cells, and, instead, potentiated it in HUVEC cells. 3. H5V cells expressed both CRH receptors (CRH-R1 and R2) mRNAs, whereas HUVEC cells expressed the CRH-R2 mRNA solely. 4. CRH increased medium nitrites and iNOS protein expression in H5V cells pretreated with the selective CRH-R1 antagonist CP 154,526. However, the selective CRH-R2 antagonist anti-Svg-30 failed to produce similar effects. In fact, anti-Svg-30 inhibited CRH-induced increase of nitrite release and iNOS expression in HUVEC cells. 5. Our results confirm the activating role of CRH on endothelial cells, although it suggests its possible inhibitory role in the late phase of the inflammatory response. NO-mediated effects of CRH on endothelial cells could be exploited in therapeutic strategies related to inflammatory and/or degenerative diseases.
Cantarella
G
G
Department of Experimental Pharmacology, University of Catania School of Medicine, I-95125 Catania, Italy.
Lempereur
L
L
Lombardo
G
G
Chiarenza
A
A
Pafumi
C
C
Zappalà
G
G
Bernardini
R
R
D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D002461:Cell Line, Transformed; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000187:drug effects* / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III; D009573:Nitrites / Q000378:metabolism; D010446:Peptide Fragments / Q000494:pharmacology; D020033:Protein Isoforms / Q000235:genetics; D011743:Pyrimidines / Q000494:pharmacology; D011758:Pyrroles / Q000494:pharmacology; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D018019:Receptors, Corticotropin-Releasing Hormone / Q000037:antagonists & inhibitors / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
C101628:CP 154526; D007375:Interleukin-1; D009573:Nitrites; D010446:Peptide Fragments; D020033:Protein Isoforms; D011743:Pyrimidines; D011758:Pyrroles; D012333:RNA, Messenger; D018019:Receptors, Corticotropin-Releasing Hormone; D014409:Tumor Necrosis Factor-alpha; C116607:antisauvagine 30; D003346:Corticotropin-Releasing Hormone; C496314:NOS3 protein, human; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III