Objective: To investigate the mechanism of airway neurogenic inflammation by studying the expression of inducible nitric oxide synthase (iNOS) and substance P in C(7)-T(5) dorsal root ganglion sensory neuron cells induced by nerve growth factor (NGF) and the role of interferon regulatory factor-1 (IRF-1).
Methods: The dorsal root ganglia neuron (DRGn) cells were primary cultured, and then stimulated with or without NGF or NGF+interferon (IFN)-γ. Subsequently the DRGn cells were transinfected with or without green fluorescent protein (GFP)-IRF-1-vshRNA, and then stimulated with or without NGF. The expressions of iNOS and substance P were detected by real-time PCR.
Results: NGF induced the mRNA expression of iNOS and substance P in dorsal root ganglion sensory neuron cells, and IFN-γ increased NGF-induced iNOS mRNA expression. The expressions of iNOS and substance P in sensory neuron cells were decreased significantly at the mRNA level after IRF-1 was blocked down by IRF-1-vshRNA transinfection.
Conclusion: NGF is involved in the airway neurogenic inflammation by prompting the expression of iNOS and substance P through transcription factor IRF-1 in airway sensory neuron cells. IRF-1 may be a therapeutic target for airway neurogenic inflammation.