Disordered pancreatic inflammatory responses and inhibition of fibrosis in CD39-null mice.
OBJECTIVE
Extracellular nucleotides are released from injured cells and bind purinergic-type 2 receptors (P2-Rs) that modulate inflammatory responses. Ectonucleotidases, such as CD39/nucleoside triphosphate diphosphohydrolase-1, hydrolyze extracellular nucleotides to integrate purinergic signaling responses. Because the role of extracellular nucleotides and CD39 in mediating inflammation and fibrosis are understood poorly, we studied the impact of CD39 gene deletion in a model of pancreatic disease.


METHODS
Pancreatitis was induced by cyclosporine pretreatment, followed by cerulein injections (50 mug/kg, 6 intraperitoneal injections/day, 3 times/wk); mice were killed at day 2, week 3, and week 6. Experimental parameters were correlated with cytokine levels in blood, RNA, and protein expression of purinergic and fibrosis markers in tissues. Immunohistochemistry and pancreatic morphometry of fibrosis were performed in wild-type and CD39-null mice. Effects of CD39 deletion on proliferation of primary pancreatic stellate cells (PSCs) were investigated in vitro.


RESULTS
Wild-type mice developed morphologic features of pancreatitis with the anticipated development of parenchymal atrophy and fibrosis. CD39 and P2-R became overexpressed in vascular and adventitious wild-type tissues. In contrast, CD39-null mice had inflammatory reactions but developed only minor pancreatic atrophy and limited fibrosis. Interferon-gamma became significantly increased in tissues and plasma of CD39-null mice. Wild-type PSCs expressed high levels of CD39 and P2-R. CD39-null PSCs showed decreased rates of proliferation and the expression of procollagen-alpha1 was inhibited significantly in vitro (P < .03).


CONCLUSIONS
CD39 deletion decreases fibrogenesis in experimental pancreatitis. Our data implicate extracellular nucleotides as modulators of PSC proliferation and collagen production in pancreatitis.
Division of Gastroenterology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard University, Boston, Massachusetts, USA.
Beat M
BM
Künzli
Philipp
P
Nuhn
Keiichi
K
Enjyoji
Yara
Y
Banz
Rex N
RN
Smith
Eva
E
Csizmadia
Detlef
D
Schuppan
Pascal O
PO
Berberat
Helmut
H
Friess
Simon C
SC
Robson
D000818:Animals; D015703:Antigens, CD / Q000235:genetics* / Q000378:metabolism; D001081:Apyrase / Q000235:genetics* / Q000378:metabolism; D018929:Cell Culture Techniques; D049109:Cell Proliferation; D004195:Disease Models, Animal; D005355:Fibrosis / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D017353:Gene Deletion; D051379:Mice; D008810:Mice, Inbred C57BL; D010179:Pancreas / Q000378:metabolism / Q000473:pathology*; D010195:Pancreatitis / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*
D015703:Antigens, CD; D001081:Apyrase; C067869:CD39 antigen