Preservation of peritoneal fibrinolysis owing to decreased transcription of plasminogen activator inhibitor-1 in peritoneal mesothelial cells suppresses postoperative adhesion formation in laparoscopic surgery
ABSTRACT BACKGROUND: Postoperative adhesion formation is regulated by peritoneal fibrinolysis, which is determined by tissue-type plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1). This study compared peritoneal fibrinolysis and adhesion formation after laparoscopic surgery (LAP) and open surgery (OP). METHODS: We divided 154 male rats into 3 groups after cecal cauterization: Control, no treatment; LAP, CO(2) pneumoperitoneum at 5 mmHg for 60 minutes; and OP, laparotomy for 60 minutes. Adhesions were quantified at day 7. The activity and mRNA level of tPA and PAI-1 were determined by enzyme-linked immunosorbent assay in plasma and peritoneal lavage and by real-time polymerase chain reaction in peritoneal mesothelial cells from omentum. We also examined peritoneal fibrinolysis in human gastric cancer patients treated with LAP (n = 14) or OP (n = 10). RESULTS: In the animal study, adhesion scores, PAI-1 activity in peritoneal lavage fluid, and PAI-1 mRNA levels in peritoneal mesothelium were significantly greater in the OP group than the control and LAP groups. In the human study, postoperative PAI-1 mRNA levels were significantly greater in the OP group than the LAP group. Additionally, PAI-1 mRNA levels and subsequent adhesion formation were induced by prolonged operative time in the OP group, but not the LAP group. CONCLUSION: Preservation of peritoneal fibrinolysis owing to decreased PAI-1 expression at the transcriptional level in peritoneal mesothelial cells is associated with suppression of postoperative adhesion formation in LAP. PAI-1 mRNA levels and subsequent adhesion formation were not induced by prolonged operative time in LAP. These results highlight the less invasiveness nature of LAP.
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ABSTRACT: Study rationale: Heparin is routinely administered postoperatively in abdominal surgery to prevent the formation of adhesions; however, there is no consensus in the literature indicating the effectiveness of such use. Objectives: This study sought to assess peritoneal fibrinolytic activity post-enterotomy of the small colon in equines treated with heparin. Methods: In the present study, 10 adult equines were divided into 2 groups of 5 animals each: the control group (CG) and treated group (TG). Both groups underwent laparotomy and enterotomy of the small colon through the right paralumbar fossa in quadrupedal position. In addition, the animals received combinations of flunixin meglumine, gentamicin and penicillin. The TG also received subcutaneous heparin (150 IU/kg, bwt q. 12 hours, 5 days). The animals were evaluated for the peritoneal concentrations of tissue plasminogen activator (tPA), plasminogen activator inhibitor type 1 (PAI-1) and D-dimer at the following time-points: prior to enterotomy (M0); 12 hours after (M1); 1 day after (M2); 2 days after (M3); 4 days after (M4); 6 days after (M5); 10 days after (M6) and 14 days after enterotomy (M7). Results: A significant difference in tPA level was observed between the groups when all time-points were combined, with a median value of 2.59 IU/mL for the CG and 2.03 IU/mL for the TG. Although no significant difference was observed when the groups were compared at different time-points, smaller tPA and D-dimer values were observed for the TG during heparin treatment. Conclusions: In addition to the finding that the TG showed a lower tPA concentration and reduced D-dimer formation, it was concluded that heparin treatment decreased the formation of fibrin clots and peritoneal fibrinolytic activity.Relevance: Because elevated D-dimer levels are directly related to a poor prognosis and high mortality rate, this study reinforced the relevance of the use of heparin in hypercoagulable states and following abdominal surgery.
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ABSTRACT: Peritoneal dissemination (PD) is the most frequent metastatic pattern of advanced gastric cancer (GC) and the main cause of death in GC patients. Human peritoneal mesothelial cell (HPMC) injury induced by gastric cancer cells (GCCs) and GCC outgrowths supported by peritoneal milky spot macrophages (PMSMs) are the key events during gastric cancer peritoneal dissemination (GCPD). In this study, we investigated whether PMSMs remodeled by GCC can induce HPMC injury and create a favorable microenvironment for GCPD. We established a tumor-associated macrophage (TAM) model using in vitro cell coculture. Normal macrophages cocultured with GCCs down-regulated expression of antigen-presenting surface molecules CD80, CD86, and MHC-II, but, notably, they up-regulated expression of phagocytic scavenger receptor CD206, which is similar to the M2 macrophage phenotype. In further experiments, various experimental methods were applied to detect the injurious effect of TAMs on HPMCs in another TAM-HPMC coculture. Our results showed that GCCs can induce HPMC apoptosis by unregulated apoptosis associated with cleaved caspase3, cleaved caspase9, and p21 proteins. HPMC growth ceased, and both early- and late-stage apoptosis were observed. Additionally, GCCs can induce HPMC fibrosis via increased expression of epithelial cell marker E-cadherin and decreased expression of mesenchymal cell marker α-SMA. Our results demonstrate that, in the GCPD process, PMSMs were remodeled by GCCs, resulting in phenotypic and functional transformation. In turn, this transformation induced HPMC injury and provided a favorable microenvironment for GCC anchorage and growth. These results may provide new insight into the mechanisms of GCPD.Biochemical and Biophysical Research Communications 08/2013; 439(3). DOI:10.1016/j.bbrc.2013.08.073 · 2.28 Impact Factor