Expression of alpha-smooth muscle actin, TGF-beta 1 and TGF-beta type II receptor during connective tissue contraction.
Closure of rat mesenteric perforation is considered to occur by connective tissue contraction, a process that has been shown to be stimulated by transforming growth factor-beta 1. In the present study, we assessed the expression of alpha-smooth muscle actin during closure by quantitative-reverse transcription-polymerase chain reaction and in situ hybridization. The expression of transforming growth factor-beta 1 and transforming growth factor-beta type II receptor was also estimated in mesenteric membranes and free peritoneal cells after wounding. A larger expression of alpha-smooth muscle actin was seen around the wound edges compared to unwounded tissue. Both alpha-smooth muscle actin and transforming growth factor-beta type II receptor were expressed during Days 0, 3, 5, 7, and 10. The expression of alpha-smooth muscle actin on Day 5 was > 100 times higher than on Day 0. Transforming growth factor-beta 1 was expressed in both membranes and free peritoneal cells of unoperated control animals but down-regulated after wounding, a finding that has not been reported previously. It reappeared on Days 7 and 10 in free peritoneal cells but not in perforated membranes. The enhanced expression of alpha-smooth muscle actin and down-regulation of transforming growth factor-beta 1 expression after wounding appears to be important phenomena in tissue contraction and repair.
Ghassemifar
M R
MR
Department of Pathology II, University Hospital, Linköping, Sweden.
Tarnuzzer
R W
RW
Chegini
N
N
Tarpila
E
E
Schultz
G S
GS
Franzen
L E
LE
D000199:Actins / Q000235:genetics*; D000818:Animals; D003238:Connective Tissue / Q000378:metabolism*; D015870:Gene Expression; D017403:In Situ Hybridization; D008297:Male; D008643:Mesentery / Q000293:injuries*; D009130:Muscle, Smooth / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D012194:RNA-Directed DNA Polymerase; D051381:Rats; D017207:Rats, Sprague-Dawley; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics*; D014945:Wound Healing
D000199:Actins; D012333:RNA, Messenger; D018125:Receptors, Transforming Growth Factor beta; D012194:RNA-Directed DNA Polymerase