Inflammatory cells as source of tachykinin-induced mucus secretion in chronic bronchitis

Regul Pept. 2005 Jan 15;124(1-3):195-201. doi: 10.1016/j.regpep.2004.07.017.

Abstract

Substance P and neurokinin A are regulatory peptides of the tachykinin family that influence many aspects of human airway function in health and diseases such as bronchial asthma or chronic obstructive pulmonary disease (COPD). Tachykinin-induced mucus secretion has been regarded as sensory nerve-dependent so far. We studied the distribution of tachykinin-mRNA and -peptide and its relation to NK-1 subtype-positive cells in human airway glands to assess if tachykinins may also be expressed in inflammatory cells. RT-PCR demonstrated the expression of tachykinin- and NK-1-mRNA in human airway tissues. In situ hybridisation resulted in preprotachykinin (PPT)-A mRNA-signal detection in inflammatory cells which were in close contact to myoepithelial cells of airway glands. NK-1 immunoreactivity was found in myoepithelial cells which were in direct contact to the PPT-A mRNA and tachykinin-positive cells. The present data directly demonstrate the presence of both PPT-A mRNA and tachykinin immunoreactivity in inflammatory airway cells which are in direct contact to NK-1 receptor positive glandular myoepithelium. Our findings indicate that besides neurally released tachykinins, also inflammatory cell-derived tachykinins may lead to glandular secretion via NK-1 receptor stimulation. This points to a major second source of these proinflammatory mediators in chronic inflammatory airway diseases such as COPD or asthma.

MeSH terms

  • Bronchitis, Chronic / genetics
  • Bronchitis, Chronic / metabolism*
  • Bronchitis, Chronic / pathology*
  • Humans
  • Immunohistochemistry
  • Mucus / metabolism*
  • Pneumonia / genetics
  • Pneumonia / metabolism*
  • Pneumonia / pathology*
  • Protein Precursors / genetics
  • Protein Precursors / metabolism
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Receptors, Neurokinin-1 / genetics
  • Receptors, Neurokinin-1 / metabolism
  • Respiratory System / metabolism
  • Respiratory System / pathology
  • Tachykinins / genetics
  • Tachykinins / metabolism*

Substances

  • Protein Precursors
  • RNA, Messenger
  • Receptors, Neurokinin-1
  • Tachykinins
  • preprotachykinin