The effect of erythropoietin on interleukin‐1β mediated increase in nitric oxide synthesis in vascular smooth muscle cells
作者:
Tetsu Akimoto,
Eiji Kusano,
Shigeaki Muto,
Nobuya Fujita,
Koji Okada,
Toshikazu Saito,
Norio Komatsu,
Shuichi Ono,
Satoru Ebata,
Yasuhiro Ando,
Sumiko Homma,
Yasushi Asano,
期刊:
Journal of Hypertension
(OVID Available online 1999)
卷期:
Volume 17,
issue 9
页码: 1249-1256
ISSN:0263-6352
年代: 1999
出版商: OVID
关键词: erythropoietin;erythropoietin receptor;protein kinase C;phospholipase-Cγ1;vascular smooth muscle cells;nitric oxide, nitric oxide synthase, interleukin-1β
数据来源: OVID
摘要:
ObjectiveRecently, we observed that recombinant human erythropoietin (rHuEPO) inhibits the interleukin (IL)-1β induced nitric oxide (NO) production and inducible NO synthase (iNOS) expression in cultured rat vascular smooth muscle cells (VSMC). The mechanisms of these inhibitory effects of rHuEPO were evaluated.MethodsReverse transcription-polymerase chain reaction (RT-PCR) was performed to identify a specific erythropoietin receptor (EpoR). Tyrosine phosphorylation of phospholipase C (PLC) was analyzed by combination of immunoprecipitation and Western blotting. Protein kinase C (PKC) activities were analyzed by phosphorylation assay of myelin basic protein (MBP4-14). VSMC were incubated with test agents for 24 h and nitrite as a stable NO metabolite was measured. iNOS mRNA and protein expression was analyzed by Northern and Western blotting, respectively.ResultsRT-PCR analysis revealed that EpoR m-RNA was expressed; furthermore, it might be alternatively spliced in VSMC. rHuEPO induced tyrosine phosphorylation of PLC-γ1 and activation of PKC. rHuEPO inhibited not only IL-1β induced nitrite production, but also the expression of iNOS mRNA and protein. These inhibitory effects of rHuEPO were reversed in the presence of PKC inhibitors, calphostin C (1 μmol/l) orstaurosporine (10 nmol=l). PKC activation by phorbol myristate acetate inhibited nitrite production. The inhibitory effect of rHuEPO on IL-1β induced nitrite production was also eliminated in PKC depleted cells or in the existence of anti-EpoR antibody.ConclusionrHuEPO inhibits IL-β induced NO production by suppressing iNOS mRNA and protein expressions through EpoR, and the PLC-γ1 and PKC pathway may be involved.
点击下载:
PDF
(351KB)
返 回