Involvement of transforming growth factor-ß3 and betaglycan in the cytoarchitecture of postoperative omental adhesions.

ABSTRACT

BACKGROUND: Adhesions commonly appear in patients after abdominal surgery, with considerable individual variation in adhesion composition and severity of the repair process. Here, we address the influence of transforming growth factor (TGF)-ß3 and betaglycan in this response, in relation to TGF-ß1, in an adhesiogenic rabbit model. MATERIALS AND METHODS: Omental adhesions were recovered 3, 7, 14, and 90 d after the implantation of a polypropylene mesh on the parietal peritoneum in New Zealand White rabbits. Omentum from nonoperated animals served as control. Tissue specimens were examined for TGF-ß3 and TGF-ß1 (Western blotting, reverse transcription-polymerase chain reaction), and TGF-ß1TGF-ß3 messenger RNA and protein expression ratios were analyzed. Immunohistochemical detection of TGF-ß3 and betaglycan was performed. RESULTS: Injury to the omentum led to mobilization of TGF-ß3 and betaglycan-expressing cells from milky spots. Fibrous zones in adhesions were simultaneous to the presence of TGF-ß1 and the membrane-bound form of betaglycan (7-d adhesions), whereas soluble betaglycan appeared in TGF-ß1-positive areas showing limited fibrosis (3-d adhesions). The elevated expression of TGF-ß3 concurrent with the presence of membrane-bound form of betaglycan was observed in zones of adipose regeneration (14-d adhesions), whereas zones of fibrous consistency were negative for TGF-ß3. CONCLUSIONS: Milky spots on the omentum contain inflammatory/immune cells positive for TGF-ß3, TGF-ß1, and betaglycan, playing a role in the damaged omentum repair. Our observations support the contribution of TGF-ß3 to tissue repair through adipose tissue regeneration and the profibrotic role of TGF-ß1 and suggest that these effects on the local wound repair response could be driven by the expression of betaglycan in its soluble or membrane-bound form.