RNA interference prevents lipopolysaccharide-induced preprotachykinin gene expression.
We showed previously that lipopolysaccharide (LPS) induces noncholinergic airway hyperreactivity to capsaicin via an upregulation of tachykinin synthesis. This study was designed to test whether double-stranded preprotachykinin (ds PPT) RNA, RNA interference (RNAi), prevents the LPS-induced alterations. First, cultured primary nodose ganglial cells of newborn Brown-Norway rats were divided into four groups: control; LPS; LPS+RNAi; and LPS+RNAi+liposome. Second, young Brown-Norway rats for the in vivo study were divided into three groups (control; LPS; and LPS+RNAi), and ds PPT RNA was microinjected bilaterally into the nodose ganglia in the LPS+RNAi group. Then, ganglial cells were collected from the culture whereas the nodose ganglia and lungs were sampled from the animals, and PPT mRNA and substance P (SP) levels were analyzed. Also, airway reactivity to capsaicin was performed in vivo. LPS induced significant increases in PPT mRNA and SP levels in vitro and in vivo and an increase in airway reactivity to capsaicin in vivo. However, ds PPT RNA, but not scrambled RNA, prevented all LPS-induced alterations. The effect of ds PPT RNA was not enhanced by liposome in vitro. Therefore, we demonstrated that the local application of RNAi prevents effectively the activation of the noncholinergic system modulating the lungs/airways.
Lai
Yih-Loong
YL
Department of Physiology, National Taiwan University College of Medicine, Taipei 100, Taiwan. tiger@ha.mc.ntu.edu.tw
Yu
Shu Chuan
SC
Chen
Mei-Jung
MJ
D000818:Animals; D000831:Animals, Newborn; D002211:Capsaicin / Q000378:metabolism; D002478:Cells, Cultured; D005541:Forced Expiratory Volume; D005786:Gene Expression Regulation / Q000502:physiology*; D007124:Immunoenzyme Techniques; D008070:Lipopolysaccharides / Q000037:antagonists & inhibitors* / Q000378:metabolism / Q000633:toxicity; D008081:Liposomes / Q000378:metabolism; D008171:Lung Diseases / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology*; D009620:Nodose Ganglion / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D011498:Protein Precursors / Q000096:biosynthesis* / Q000235:genetics; D012313:RNA / Q000737:chemistry / Q000235:genetics; D034622:RNA Interference / Q000502:physiology*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D011914:Rats, Inbred BN; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013373:Substance P / Q000378:metabolism; D015320:Tachykinins / Q000096:biosynthesis* / Q000235:genetics
D008070:Lipopolysaccharides; D008081:Liposomes; D011498:Protein Precursors; D012333:RNA, Messenger; D015320:Tachykinins; C044206:preprotachykinin; D013373:Substance P; D012313:RNA; D002211:Capsaicin