Chymase-positive mast cells play a role in the vascular component of airway remodeling in asthma.
BACKGROUND
There is increasing evidence to support a role for total mast cells (MC(TOT)) in the vascular component of airway remodeling in asthma. On the contrary, up to now, no study has addressed the role of chymase-positive mast cells (MC(TC)) in microvasculature changes.


OBJECTIVE
We sought to assess the role of MC(TC) in the vascular component of airway remodeling in asthma.


METHODS
We recruited 8 patients with mild-to-moderate asthma and 8 healthy volunteers as a control group. Fiberoptic bronchoscopy with endobronchial biopsy was successfully performed in all subjects. Immunostaining was performed for quantification of vessels, vascular endothelial growth factor (VEGF)-positive cells, MC(TOT), and MC(TC).


RESULTS
Compared with those from healthy subjects, endobronchial biopsy specimens from asthmatic patients showed increased numbers of MC(TOT) and MC(TC) and VEGF(+) cells (P < .05). In asthmatic patients the number of vessels and the vascular area was also greater than in healthy subjects (P < .05). Additionally, in asthmatic patients the number of MC(TC) was significantly related to the vascular area (r(s) = 0.74, P < .01) and to the number of VEGF(+) cells (r(s) = 0.78, P < .01). Moreover, a colocalization study revealed that MC(TC) were a relevant cellular source of VEGF. Finally, a 6-week treatment with inhaled fluticasone propionate was able to reduce MC(TC) numbers.


CONCLUSIONS
MC(TC) can play a role in the vascular component of airway remodeling in asthma, possibly through induction of VEGF.


CONCLUSIONS
Specific targeting of MC(TC) might be a tool for treating vascular remodeling in asthma.
Zanini
Andrea
A
Salvatore Maugeri Foundation, Division of Pneumology, IRCCS Rehabilitation Institute of Tradate, Tradate, Italy. azanini@fsm.it
Chetta
Alfredo
A
Saetta
Marina
M
Baraldo
Simonetta
S
D'Ippolito
Raffaele
R
Castagnaro
Antonio
A
Neri
Margherita
M
Olivieri
Dario
D
D000328:Adult; D000730:Androstadienes / Q000008:administration & dosage / Q000627:therapeutic use; D001249:Asthma / Q000188:drug therapy / Q000473:pathology / Q000503:physiopathology*; D001808:Blood Vessels / Q000503:physiopathology; D001980:Bronchi / Q000098:blood supply* / Q000473:pathology / Q000503:physiopathology*; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000627:therapeutic use; D001999:Bronchoscopy; D002452:Cell Count; D053818:Chymases / Q000378:metabolism*; D004334:Drug Administration Schedule; D005260:Female; D005336:Fiber Optic Technology; D000068298:Fluticasone; D006801:Humans; D008297:Male; D008407:Mast Cells / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism / Q000473:pathology; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
D000730:Androstadienes; D001993:Bronchodilator Agents; D042461:Vascular Endothelial Growth Factor A; D000068298:Fluticasone; D053818:Chymases