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IL‐1β Participates in Sensitization of Bronchopulmonary C‐fibers Induced by Prenatal Nicotinic Exposure (PNE) in Rat Pups
Author(s) -
Zhao Lei,
Zhuang Jianguo,
Xu Fadi
Publication year - 2016
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.30.1_supplement.1261.10
Subject(s) - anesthesia , medicine , capsaicin , apnea , endocrinology , receptor
Maternal smoking during pregnancy has the highest risk for inducing sudden infant death syndrome (SIDS) characterized by cardiorespiratory failure including aggravated apnea. We recently found that PNE promoted hypoxia‐induced central apnea by sensitizing the bronchopulmonary C‐fibers (PFCs), i.e., prolonged PCF firing and apneic response to right atrial bolus injection of capsaicin, a selective stimulant to PCFs (Zhuang et al., AJP 2015), but the relevant mechanisms have not been fully understood. IL‐1β is a potent stimulant to PCFs and its concentration in serum is substantially increased in the majority of SIDS victims (Vennemann et al., Int J Legal Med. 2012). Thus we asked whether PNE increased IL‐1β release into the lungs and IL‐1 type I receptor (IL1R1) expression in nodose/jugular (N/J) ganglion, especially the vagal pulmonary C‐neurons, and if so, whether the prolonged apneic response to capsaicin by PNE would be shortened by pretreatment of IL‐1Ra (an IL1R1 antagonist). To this end, we collected BALF to detect gene and protein levels of IL‐1β released into the airways and lungs, harvested N/J ganglion for determining IL1R1 gene and protein expression, and extracted vagal pulmonary C‐neurons retrograde‐traced by DiI for analysis of IL1R1 mRNA. Subsequently, in anesthetized and spontaneously breathing pups, we compared the respiratory responses to atrial bolus injection of capsaicin before and after IL‐1R1 blockade. Our results showed that PNE obviously elevated IL‐1β in BALF, and upregulated IL1R1 gene and protein expression of N/J ganglion, particularly IL1R1 mRNA in pulmonary C neurons. Moreover, the PNE‐induced prolongation of the apneic response to capsaicin was significantly shortened by ~55% after IL‐1R1 blockade. Our results suggest that PNE promotes IL‐1β release into the lungs and IL1R1 expression in vagal pulmonary C‐neurons to sensitize PCFs, contributing to the prolongation of the PCF‐mediated apnea. Support or Funding Information Supported by HL119683 and HL107462