YC-1 attenuates LPS-induced proinflammatory responses and activation of nuclear factor-kappaB in microglia.
OBJECTIVE
An inflammatory response in the central nervous system mediated by the activation of microglia is a key event in the early stages of the development of neurodegenerative diseases. LPS has been reported to cause marked microglia activation. It is very important to develop drugs that can inhibit microglia activation and neuroinflammation. Here, we investigated the inhibitory effect of YC-1, a known activator of soluble guanylyl cyclase, against LPS-induced inflammatory responses in microglia.


METHODS
To understand the inhibitory effects of YC-1 on LPS-induced neuroinflammation, primary cultures of rat microglia and the microglia cell line BV-2 were used. To examine the mechanism of action of YC-1, LPS-induced nitric oxide (NO) and prostaglandin E2 (PGE2) production, iNOS, COX-2 and cytokine expression were analyzed by Griess reaction, ELISA, Western blotting and RT-PCR, respectively. The effect of YC-1 on LPS-induced activation of nuclear factor kappa B (NF-kappaB) was studied by NF-kappaB reporter assay and immunofluorocytochemistry.


RESULTS
YC-1 inhibited LPS-induced production of NO and PGE2 in a concentration-dependent manner. The protein and mRNA expression of iNOS and COX-2 in response to LPS application were also decreased by YC-1. In addition, YC-1 effectively reduced LPS-induced expression of the mRNA for the proinflammatory cytokines, TNF-alpha and IL-1beta. Furthermore, YC-1 inhibited LPS-induced NF-kappaB activation in microglia.


CONCLUSIONS
YC-1 was able to inhibit LPS-induced iNOS and COX-2 expression and NF-kappaB activation, indicating that YC-1 may be developed as an anti-inflammatory neuroprotective agent.
Lu
D-Y
DY
College of Medicine, Pharmacological Institute, National Taiwan University, Taipei, Taiwan.
Tang
C-H
CH
Liou
H-C
HC
Teng
C-M
CM
Jeng
K-C G
KC
Kuo
S-C
SC
Lee
F-Y
FY
Fu
W-M
WM
D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000494:pharmacology; D017869:Cyclic GMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D015232:Dinoprostone / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D020536:Enzyme Activators / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D006162:Guanylate Cyclase / Q000037:antagonists & inhibitors; D007191:Indazoles / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D017628:Microglia / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism*; D009569:Nitric Oxide / Q000096:biosynthesis; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000378:metabolism; D010069:Oxadiazoles / Q000494:pharmacology; D011392:Proline / Q000031:analogs & derivatives / Q000494:pharmacology; D011810:Quinoxalines / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013859:Thiocarbamates / Q000494:pharmacology; D013873:Thionucleotides / Q000494:pharmacology
C095284:1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one; D020536:Enzyme Activators; D007191:Indazoles; D008070:Lipopolysaccharides; D016328:NF-kappa B; D010069:Oxadiazoles; D011810:Quinoxalines; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D013859:Thiocarbamates; D013873:Thionucleotides; C066229:prolinedithiocarbamate; C090937:3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole; C098740:8-bromo-beta-phenyl-1,N(2)-ethenoguanosine 3',5'-cyclic monophosphorothioate; D009569:Nitric Oxide; D011392:Proline; D008156:Luciferases; D052247:Nitric Oxide Synthase Type II; D051546:Cyclooxygenase 2; D017869:Cyclic GMP-Dependent Protein Kinases; D006162:Guanylate Cyclase; D006152:Cyclic GMP; D015232:Dinoprostone