Dynamics and localization of activin A expression in rat gastric ulcers.
BACKGROUND
Activin A, the homodimer of the activin/inhibin betaA subunit, has been shown to participate in cutaneous wound healing. In this study we intended to determine its part in gastric ulceration.


METHODS
Activin A expression was studied by immunohistochemistry and in situ hybridization in acetic-acid-induced chronic gastric ulcers in rat. The dynamics of this process were also assessed by quantitative real time RT-PCR and RNase protection assays (RPA). The effects of different doses of this cytokine on epithelial and mesenchymal cell proliferation were quantitated in vitro.


RESULTS
Low amounts of activin A and its mRNA were expressed by epithelia, endothelia and fibroblasts in intact gastric tissue. Granulation tissue of gastric ulcers and gastric glands adjacent to the ulcer rim expressed markedly increased amounts of activin protein as well as activin/inhibin betaA mRNA. RPA and RT-PCR studies revealed a more than 3-fold increase in the relative abundance of this mRNA. Activin A did not affect the proliferation rate of fibroblasts and epithelial cells in vitro.


CONCLUSIONS
Activin A participates in gastric ulcer healing in a similar fashion as in cutaneous wounding. Its expression on protein and mRNA level is markedly increased in ulcer base and rim.
Dept. of Medicine B, Institute of Physiological Chemistry and Pathobiochemistry, University of Münster, Münster, Germany.
J C
JC
Becker
M
M
Hertel
A
A
Markmann
M
M
Shahin
S
S
Werner
W
W
Domschke
T
T
Pohle
D028341:Activins / Q000008:administration & dosage / Q000096:biosynthesis* / Q000235:genetics*; D000818:Animals; D015415:Biomarkers / Q000032:analysis; D002452:Cell Count; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology; D005753:Gastric Mucosa / Q000166:cytology / Q000378:metabolism; D015870:Gene Expression; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D028322:Inhibin-beta Subunits / Q000008:administration & dosage / Q000096:biosynthesis* / Q000235:genetics*; D008297:Male; D009092:Mucous Membrane / Q000166:cytology / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013276:Stomach Ulcer / Q000235:genetics* / Q000378:metabolism*; D013997:Time Factors
D015415:Biomarkers; D012333:RNA, Messenger; C422405:activin A; C103008:inhibin beta A subunit; D028341:Activins; D028322:Inhibin-beta Subunits