[Expressions of early growth response 1 and tissue factor in caerulein-induced acute pancreatitis tissues in rats].
OBJECTIVE
To observe the expressions of early growth response 1 (Egr-1) and tissue factor (TF) in rat tissues of acute pancreatitis induced by caerulein and to explore their significance.


METHODS
Pancreatitis was induced in rats by high-dose intraabdominal caerulein injection. The changes of Egr-1 mRNA and protein in pancreas were measured by quantitative PCR and Western blotting, and the localization of Egr-1 protein in acinar cells was visualized by immunohistochemistry. TF mRNA levels were also measured by quantitative PCR. High-dose bombesin-stimulated rats served as the negative control.


RESULTS
Egr-1 mRNA was rapidly increased in the pancreas of rats stimulated by high-dose cearulein, and reached the peak level 30 min after the stimulation, whereas band for peak Egr-1 protein level was visualized by Western blotting till 2 h after stimulation. Immunohistochemistry showed that almost every acinar cell in the pancreas was Egr-1-positive, especially in the nucleus. In line with Egr-1 activation, TF mRNA was detected 1 h after the stimulation and increased steadily within the initial 4 h. Only a small quantity of Egr-1 mRNA expression was observed in bombesin-stimulated rats, in which no Egr-1 protein or TF mRNA were detected.


CONCLUSIONS
Egr-1 mRNA and protein were up-regulated in the early stage of pancreatitis. Egr-1, as a pro-inflammatory transcriptional factor, probably plays an important role in the initiation of acute pancreatitis, and its action might be partially mediated through the up-regulation of TF expression.
Chen
Xue-qing
XQ
Department of Gastroenterology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China. chenxq@bfbt.com
Jiang
Bo
B
Song
Yu-gang
YG
Zhi
Fa-chao
FC
Gong
Lan-bo
LB
D000818:Animals; D002108:Ceruletide; D051766:Early Growth Response Protein 1 / Q000096:biosynthesis* / Q000235:genetics; D008297:Male; D010179:Pancreas / Q000378:metabolism*; D010195:Pancreatitis / Q000139:chemically induced / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D013925:Thromboplastin / Q000096:biosynthesis* / Q000235:genetics
D051766:Early Growth Response Protein 1; D012333:RNA, Messenger; D002108:Ceruletide; D013925:Thromboplastin