Stress induces substance P in vagal sensory neurons innervating the mouse airways.
Clin Exp Allergy
; 36(8): 1001-10, 2006 Aug.
Article
en En
| MEDLINE
| ID: mdl-16911356
ABSTRACT
BACKGROUND:
Tachykinins-like substance P (SP) have been shown to play an important role in initiating and perpetuating airway inflammation. Furthermore, they are supposed to be released into tissues in response to stress.OBJECTIVE:
The aim of this study was to investigate the effects of stress alone or in combination with allergic airway inflammation on SP expression in sensory neurons innervating the mouse airways.METHODS:
Balb/c mice were systemically sensitized to ovalbumin (OVA), followed by allergen aerosol exposure, and compared with non-sensitized controls. Additionally, OVA-sensitized and -challenged and non-sensitized mice were exposed to sound stress. SP expression in airway-specific and overall vagal sensory neurons of the jugular and nodose ganglion complex was analysed using retrograde neuronal tracing in combination with immunohistochemistry. Preprotachykinin A (PPT-A) mRNA, the precursor for SP, was quantified in lung tissue by real-time PCR. Bronchoalveolar lavage (BAL) fluid was obtained, and cell numbers and differentiation were determined.RESULTS:
Stress and/or allergic airway inflammation significantly increased SP expression in retrograde-labelled vagal sensory neurons from the mouse lower airways compared with controls [stress 15.7+/-0.8% (% of retrograde-labelled neurons, mean+/-SEM); allergen 17.9+/-0.4%; allergen/stress 13.1+/-0.7% vs. controls 6.3+/-0.3%]. Similarly, SP expression increased in overall vagal sensory neurons identified by the neuronal marker protein gene product (PGP) 9.5 [stress 9.3+/-0.6% (% of PGP 9.5-positive neurons, means+/-SEM); allergen 12.5+/-0.4%; allergen/stress 10.2+/-0.4% vs. controls 5.1+/-0.3%]. Furthermore, stress significantly increased PPT-A mRNA expression in lung tissue from OVA-sensitized and -challenged animals, and immune cells were identified as an additional source of SP in the lung by immunohistochemistry. Associated with enhanced neuronal SP expression, a significantly higher number of leucocytes were found in the BAL following allergen exposure. Further, stress significantly increased allergen-induced airway inflammation identified by increased leucocyte numbers in BAL fluids.CONCLUSION:
The central event of sound stress leads to the stimulation of SP expression in airway-specific neurons. However, in sensitized stressed mice an additional local source of SP (probably inflammatory cells) might enhance allergic airway inflammation.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Hipersensibilidad Respiratoria
/
Estrés Psicológico
/
Sustancia P
/
Pulmón
/
Neuronas Aferentes
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
Clin Exp Allergy
Asunto de la revista:
ALERGIA E IMUNOLOGIA
Año:
2006
Tipo del documento:
Article