Marked stem cell factor expression in the airways of lung transplant recipients.
BACKGROUND
Airways repair is critical to lung function following transplantation. We hypothesised that the stem cell factor (SCF) could play a role in this setting.


METHODS
We studied 9 lung transplant recipients (LTx recipients) during their first year postgraft, and evaluated SCF mRNA expression in bronchial biopsy specimens using on-line fluorescent PCR and SCF protein levels in bronchoalveolar lavage (BAL) and serum using ELISA. The expression of SCF receptor Kit was assessed using immunostaining of paraffin-embedded bronchial sections.


RESULTS
SCF mRNA was highly expressed during the early postgraft period [Month (M)1-M3] (300% increase vs controls: 356 vs 1.2 pg SCF/microg GAPDH cDNA, p < 0.001) and decreased thereafter (M4-M12: 187 pg/microg), although remaining at all times 10-100 times higher than in controls. While SCF protein levels in BAL were similar in LTx recipients and in controls, the SCF serum levels were at all times higher in LTx recipients than in controls (p < 0.05), with no relationship between these levels and the acute complications of the graft. Finally, Kit was strongly expressed by the mast cells as well as by the bronchial epithelium of LTx recipients.


CONCLUSIONS
SCF and Kit are expressed in bronchial biopsies from lung transplant recipients irrespective of the clinical status of the graft. A role for these factors in tissue repair following lung transplantation is hypothesised.
Da Silva
Carla A
CA
1EA 3771 Inflammation and environment in asthma, Faculté de Pharmacie, BP 60024, 67401 Illkirch Cedex, France. carla.dasilva@pharma.u-strasbg.fr
Adda
Mélanie
M
Stern
Marc
M
de Blay
Frédéric
F
Frossard
Nelly
N
Israel-Biet
Dominique
D
D000208:Acute Disease; D000328:Adult; D001706:Biopsy; D001980:Bronchi / Q000166:cytology / Q000502:physiology*; D001992:Bronchoalveolar Lavage Fluid; D005260:Female; D015870:Gene Expression / Q000502:physiology; D006801:Humans; D016040:Lung Transplantation / Q000502:physiology*; D008297:Male; D008407:Mast Cells / Q000502:physiology; D008875:Middle Aged; D011183:Postoperative Complications; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D020545:Respiratory Mucosa / Q000166:cytology / Q000502:physiology*; D012697:Serine Endopeptidases / Q000378:metabolism; D019089:Stem Cell Factor / Q000097:blood / Q000235:genetics*; D053802:Tryptases
D012333:RNA, Messenger; D019089:Stem Cell Factor; D019009:Proto-Oncogene Proteins c-kit; D012697:Serine Endopeptidases; D053802:Tryptases