Knockdown of neurokinin-1 receptor expression by small interfering RNA prevents the development of allergic rhinitis in rats.
OBJECTIVE
This study is aimed at exploring the role of neurokinin-1 receptor (NK-1R) in the development of allergic rhinitis (AR) in rats.


METHODS
Sprague-Dawley rats were sensitized and challenged with ovalbumin to induce AR. The rats were treated intranasally with saline, control, or NK-1R-specific small interfering RNA (siRNA) before and during the challenge period. The numbers of sneezes and nose rubs and amount of nasal secretion in individual rats were measured. The levels of NK-1R expression in the nasal mucosal tissues after the last challenge were determined. The numbers of eosinophils in the collected nasal lavage fluid and the levels of serum interleukin (IL)-5 in individual rats were determined.


RESULTS
The levels of NK-1R expression in the nasal mucosal tissues of the AR rats that had been treated with saline or control siRNA were significantly higher than those in the healthy controls and the rats treated with NK-1R-specific siRNA, demonstrating NK-1R silencing. Furthermore, knockdown of NK-1R expression significantly reduced the amounts of sneezing, nose rubbing, and nasal secretions in AR rats. Knockdown of NK-1R expression also significantly eliminated eosinophil infiltration in the nasal tissues and reduced the levels of serum IL-5 in rats.


CONCLUSIONS
Knockdown of NK-1R expression decreased allergic inflammation in nasal mucosal tissues and alleviated the allergic rhinitis symptoms, suggesting that NK-1R may be a critical mediator of the development of AR.
Department of Otorhinolaryngology, Huadong Hospital, Shanghai Medical College, Fudan University, Shanghai, 200040, China.
Hong
H
Wang
Ruxin
R
Zhang
Jing
J
Wu
Hua
H
Hu
D000485:Allergens; D000818:Animals; D004804:Eosinophils / Q000166:cytology / Q000187:drug effects; D055785:Gene Knockdown Techniques; D015848:Interleukin-5 / Q000276:immunology; D007958:Leukocyte Count; D008297:Male; D017817:Nasal Lavage Fluid / Q000166:cytology; D010047:Ovalbumin; D034741:RNA, Small Interfering / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D018040:Receptors, Neurokinin-1 / Q000235:genetics*; D065631:Rhinitis, Allergic; D012221:Rhinitis, Allergic, Perennial / Q000276:immunology / Q000517:prevention & control*
D000485:Allergens; D015848:Interleukin-5; D034741:RNA, Small Interfering; D018040:Receptors, Neurokinin-1; D010047:Ovalbumin