Cytokines decrease sGC in pulmonary artery smooth muscle cells via NO-dependent and NO-independent mechanisms.
Exposure of rat pulmonary artery smooth muscle cells (rPASMC) to cytokines leads to nitric oxide (NO) production by NO synthase 2 (NOS2). NO stimulates cGMP synthesis by soluble guanylate cyclase (sGC), a heterodimer composed of alpha(1)- and beta(1)-subunits. Prolonged exposure of rPASMC to NO decreases sGC subunit mRNA and protein levels. The objective of this study was to determine whether levels of NO produced endogenously by NOS2 are sufficient to decrease sGC expression in rPASMC. Interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) increased NOS2 mRNA levels and decreased sGC subunit mRNA levels. Exposure of rPASMC to IL-1beta and TNF-alpha for 24 h decreased sGC subunit protein levels and NO-stimulated sGC enzyme activity. L-N(6)-(1-iminoethyl)lysine (NOS2 inhibitor) or 1H-[1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one (sGC inhibitor) partially prevented the cytokine-mediated decrease in sGC subunit mRNA levels. However, cytokines also decreased sGC subunit mRNA levels in PASMC derived from NOS2-deficient mice. These results demonstrate that levels of NO and cGMP produced in cytokine-exposed PASMC are sufficient to decrease sGC subunit mRNA levels. In addition, cytokines can decrease sGC subunit mRNA levels via NO-independent mechanisms.
Takata
M
M
Cardiovascular Research Center and Arthritis Unit, Massachusetts General Hospital, and Departments of Medicine and Anesthesia, Harvard Medical School, Charlestown, Massachusetts 02129, USA.
Filippov
G
G
Liu
H
H
Ichinose
F
F
Janssens
S
S
Bloch
D B
DB
Bloch
K D
KD
D000818:Animals; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism* / Q000494:pharmacology; D004795:Enzyme Stability / Q000187:drug effects; D006162:Guanylate Cyclase / Q000235:genetics / Q000378:metabolism*; D007375:Interleukin-1 / Q000378:metabolism / Q000494:pharmacology; D051379:Mice; D018345:Mice, Knockout; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D021122:Protein Subunits; D011651:Pulmonary Artery / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012995:Solubility; D014158:Transcription, Genetic / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism / Q000494:pharmacology
D016207:Cytokines; D007375:Interleukin-1; D021122:Protein Subunits; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496317:Nos2 protein, mouse; C496318:Nos2 protein, rat; D006162:Guanylate Cyclase