Localization of postresection EGF receptor expression using laser capture microdissection.
OBJECTIVE
Epidermal growth factor (EGF) and its receptor (EGFR) are key components in the genesis of adaptation after small bowel resection (SBR). Within intestinal homogenates, EGFR expression is increased after SBR; however, the exact cells responsible for altered EGFR expression are unknown. In this study, laser capture microdissection (LCM) microscopy was used to elucidate the specific cellular compartment(s) responsible for postresection changes in EGFR expression.


METHODS
Male ICR mice underwent a 50% proximal SBR or sham operation. After 3 days, frozen sections were taken from the remnant ileum. Individual cells from villi, crypt, muscularis, and mesenchymal compartments were isolated by LCM. EGFR mRNA expression for each cell compartment was quantified using real-time polymerase chain reaction (PCR).


RESULTS
EGFR expression was increased after SBR within the crypt (2-fold) and muscularis compartments (3-fold). There were no changes detected after SBR in the villus tips or mesenchymal compartments.


CONCLUSIONS
Increased expression of EGFR in crypts directly correlates with the zone of cell proliferation and supports the hypothesis that EGFR signaling is crucial for the mitogenic stimulus for adaptation. The finding of increased EGFR expression in the muscular compartment is novel and may implicate a role for EGFR as a mediator of the muscular hyperplasia seen after massive SBR.
Knott
Andrew W
AW
Division of Pediatric Surgery, Cincinnati Children's Hospital Medical Center, and the Department of Surgery, University of Cincinnati College of Medicine, Cincinnati, Ohio 45229-3039, USA.
Erwin
Christopher R
CR
Profitt
Sherri A
SA
Juno
Russell J
RJ
Warner
Brad W
BW
D000222:Adaptation, Physiological; D000818:Animals; D002469:Cell Separation / Q000295:instrumentation / Q000379:methods*; D003199:Computer Systems; D066246:ErbB Receptors / Q000096:biosynthesis* / Q000235:genetics; D005629:Frozen Sections; D016591:Histocytological Preparation Techniques / Q000295:instrumentation; D007082:Ileum / Q000601:surgery* / Q000648:ultrastructure; D007413:Intestinal Mucosa / Q000737:chemistry / Q000648:ultrastructure; D007834:Lasers; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D008871:Microvilli / Q000737:chemistry / Q000648:ultrastructure; D009130:Muscle, Smooth / Q000737:chemistry / Q000648:ultrastructure; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000302:isolation & purification; D012778:Short Bowel Syndrome / Q000378:metabolism* / Q000473:pathology
D012333:RNA, Messenger; D066246:ErbB Receptors