Mast cell chymase expression in Helicobacter pylori-associated gastritis.
OBJECTIVE
To study the role of mast cell chymase in the inflammatory processes of human chronic gastritis. Experimental studies have shown that mast cell chymase stimulates inflammatory cell accumulation, and contributes to angiotensin II formation.


RESULTS
Tissue sections from human stomachs with Helicobacter pylori-associated gastritis (surgery/autopsy n = 20; biopsy n = 16) and normal stomachs (n = 10) were studied using immunohistochemical single and double labelling techniques. Monoclonal antibodies used were directed against mast cell chymase, tryptase, neutrophils (CD66b, elastase, and myeloperoxidase), macrophages, T-lymphocytes, and interleukin (IL)-4. The expression of angiotensin-converting enzyme and angiotensin II type 1 receptor was investigated using immunohistochemical analysis and the reverse transcription-polymerase chain reaction. The number of chymase-positive mast cells was significantly higher (P < 0.0001) in H. pylori-associated gastritis than in normal stomachs. Increased expression of chymase in inflamed mucosa was closely related to an increase in the accumulation of neutrophils, macrophages, T-lymphocytes, and IL-4-positive cells. The expression of angiotensin-converting enzyme and angiotensin II type 1 receptor was not altered in gastritis specimens.


CONCLUSIONS
These observations suggest that mast cell chymase may be an important mediator in the inflammatory processes of human H. pylori-associated gastritis.
Matsuo
T
T
Department of Pathology, Osaka City University Graduate School of Medicine, Japan.
Ikura
Y
Y
Ohsawa
M
M
Ogami
M
M
Kayo
S
S
Yoshimi
N
N
Hai
E
E
Naruko
T
T
Ohishi
M
M
Higuchi
K
K
Arakawa
T
T
Ueda
M
M
D002908:Chronic Disease; D053818:Chymases; D005753:Gastric Mucosa / Q000737:chemistry / Q000201:enzymology / Q000473:pathology; D005756:Gastritis / Q000150:complications / Q000201:enzymology* / Q000378:metabolism; D015870:Gene Expression; D016481:Helicobacter Infections / Q000150:complications* / Q000382:microbiology; D016480:Helicobacter pylori; D006801:Humans; D007150:Immunohistochemistry; D015847:Interleukin-4 / Q000032:analysis; D008407:Mast Cells / Q000201:enzymology* / Q000473:pathology; D007703:Peptidyl-Dipeptidase A / Q000032:analysis / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D044140:Receptor, Angiotensin, Type 1 / Q000032:analysis / Q000235:genetics; D012697:Serine Endopeptidases / Q000096:biosynthesis*
D012333:RNA, Messenger; D044140:Receptor, Angiotensin, Type 1; D015847:Interleukin-4; D007703:Peptidyl-Dipeptidase A; D012697:Serine Endopeptidases; D053818:Chymases