TRPV1 and TRPA1 in Lung Inflammation and Airway Hyperresponsiveness Induced by Fine Particulate Matter (PM2.5)

Oxid Med Cell Longev. 2019 Jun 2:2019:7450151. doi: 10.1155/2019/7450151. eCollection 2019.

Abstract

Exposure to fine particulate matter (PM2.5) has been associated with lung inflammation and airway hyperresponsiveness (AHR). Transient receptor potential (TRP) vanilloid 1 (TRPV1) and ankyrin 1 (TRPA1) both may play important roles in lung inflammation and AHR. We investigated whether PM2.5-induced lung inflammation and AHR could be prevented by blocking TRPV1 and TRPA1 channels. Mice were injected intraperitoneally with AMG9810 (30 mg/kg, a TRPV1 antagonist) or A967079 (30 mg/kg, a TRPA1 antagonist) or their combination or vehicle (PBS) one hour before intranasal instillation of PM2.5 (7.8 mg/kg) or vehicle (PBS) for two consecutive days, and then the mice were studied 24 h later. All pretreatments inhibited PM2.5-induced AHR and inflammatory infiltration in the lung tissue and decreased inflammatory cytokine levels in the bronchoalveolar lavage fluid, together with oxidant levels in the lung. AMG9810 inhibited MFF expression and increased MFN2 expression while A967079 inhibited DRP1 expression and increased OPA1 expression; combined pretreatment reduced MFF and DPR1 expression and increased MFN2 and OPA1 expression. All pretreatments inhibited the activation of the TLR4/NF-κB pathway, while A967079 alone, and combined with AMG9810 also reduced the activation of the NLRP3/caspase-1 pathway. Both TRPV1 and TRPA1 channels play an important role in PM2.5-induced lung inflammation and AHR. However, inhibition of the TRPA1 channel or combined inhibition of TRPA1 and TRPV1 channels resulted in greater inhibitory effect on PM2.5-induced lung injury through regulating the mitochondrial fission/fusion proteins and inhibiting the TLR4/NF-κB and NLRP3/caspase-1 pathways.

MeSH terms

  • Acrylamides / pharmacology
  • Animals
  • Bridged Bicyclo Compounds, Heterocyclic / pharmacology
  • Bronchoalveolar Lavage Fluid
  • Cytokines / metabolism
  • Disease Models, Animal
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mitochondrial Dynamics / drug effects
  • Oxidative Stress / drug effects
  • Oximes / pharmacology
  • Particle Size
  • Particulate Matter / toxicity*
  • Pneumonia / etiology*
  • Pneumonia / metabolism
  • Pneumonia / pathology
  • Respiratory Hypersensitivity / etiology*
  • Respiratory Hypersensitivity / metabolism
  • Respiratory Hypersensitivity / pathology
  • Signal Transduction / drug effects
  • TRPA1 Cation Channel / antagonists & inhibitors
  • TRPA1 Cation Channel / biosynthesis
  • TRPA1 Cation Channel / metabolism*
  • TRPV Cation Channels / antagonists & inhibitors
  • TRPV Cation Channels / biosynthesis
  • TRPV Cation Channels / metabolism*

Substances

  • 3-(4-t-butylphenyl)-N-(2,3-dihydrobenzo(b)(1,4)dioxin-6-yl)acrylamide
  • A 967079
  • Acrylamides
  • Bridged Bicyclo Compounds, Heterocyclic
  • Cytokines
  • Oximes
  • Particulate Matter
  • TRPA1 Cation Channel
  • TRPV Cation Channels
  • TRPV1 protein, mouse
  • Trpa1 protein, mouse