Effect of NF-κB signal pathway on mucus secretion induced by atmospheric PM2.5 in asthmatic rats

Ying Liu; Bo Zhang; Tianrong Zhang; Haodong Wang; Liping Peng; Liting Zhou

doi:10.1016/j.ecoenv.2019.110094

Effect of NF-κB signal pathway on mucus secretion induced by atmospheric PM_2.5 in asthmatic rats

Ecotoxicol Environ Saf. 2020 Mar 1:190:110094. doi: 10.1016/j.ecoenv.2019.110094. Epub 2019 Dec 20.

Authors

Ying Liu¹, Bo Zhang², Tianrong Zhang³, Haodong Wang⁴, Liping Peng⁵, Liting Zhou⁶

Affiliations

¹ Department of Respiratory Medicine, The First Hospital of Jilin University, Jilin University, Changchun, China.
² Department of Pediatric Neurology, The First Hospital of Jilin University, Jilin University, Changchun, China.
³ Department of Occupational and Environmental Health, School of Public Health, Jilin University, Changchun, China.
⁴ Department of Vascular Surgery, The First Hospital of Jilin University, Jilin University, Changchun, China.
⁵ Department of Respiratory Medicine, The First Hospital of Jilin University, Jilin University, Changchun, China. Electronic address: pengliping64@yahoo.cn.
⁶ Department of Respiratory Medicine, The First Hospital of Jilin University, Jilin University, Changchun, China; Department of Occupational and Environmental Health, School of Public Health, Jilin University, Changchun, China. Electronic address: zhoulttg@163.com.

PMID: 31869718
DOI: 10.1016/j.ecoenv.2019.110094

Abstract

Background: Exposure to PM_2.5 can stimulate the mucus secretion of airway, affecting the development of bronchial asthma. NF-κB signal pathway plays an important role in inflammation and dysimmunity, what may contribute to the mucus secretion. The present study was undertaken to explore the effect of NF-κB signal pathway on mucus secretion induced by PM_2.5 in rats with bronchial asthma.

Methods: Fifty rats (25 males and 25 females) were divided randomly into the control group, ovalbumin asthmatic model group, asthma low-, middle- and high-dose groups (n = 10, 5 males and 5 females each group). The control group, ovalbumin asthmatic model group received physiological saline; the asthma low-, middle- and high-dose groups received 1.5, 7.5 and 37.5 mg/kg PM_2.5 on saline, which instilled into the trachea at 2-day intervals for two doses. Lung histopathology was observed by HE staining. The mRNA levels of NF-κB family gens were detected with real time PCR. IκB-α protein expression levels were detected with Western blot. IL-1β, TNF-α and Muc5ac levels were detected by ELISA.

Results: Respiratory mucus secretion increased with increasing dose of PM_2.5. Compared with healthy rats, the protein expression levels of IκB-α were significantly lower in the lung of asthmatic rats (p < 0.05), while the relative mRNA expression levels of NF-κB family genes in tracheal tissue and in lung were significantly higher in the asthmatic rats (p < 0.05). Serum IL-1β levels were significantly higher in the high-dose group than in the control group. Muc5ac protein levels in the trachea were higher in the high-dose compared with the low-and middle-dose groups.

Conclusion: Short-term exposure to a high concentration of PM_2.5 could up-regulate the mRNA expression levels of NF-κB family genes, activate the NF-κB signal pathway, stimulate more IL-1β and mucus secretion in rats with bronchial asthma. NF-κB signal pathway may regulate the level of IL-1β, which could influence the mucus secretion induced by PM_2.5 in asthmatic rats.

Keywords: Bronchial asthma; Inflammation; Mucus secretion; NF-κB signaling pathway; PM(2.5).

MeSH terms

Air Pollutants / toxicity*
Animals
Asthma / immunology
Female
Inflammation / metabolism
Lung / drug effects
Male
Mucus / metabolism
NF-KappaB Inhibitor alpha / metabolism
NF-kappa B / metabolism*
Ovalbumin
Particulate Matter / toxicity*
Rats
Signal Transduction / drug effects
Tumor Necrosis Factor-alpha / metabolism

Substances

Air Pollutants
NF-kappa B
Particulate Matter
Tumor Necrosis Factor-alpha
NF-KappaB Inhibitor alpha
Ovalbumin