system
Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, METHODS, RESULTS. Meshes: Animals, Escherichia coli Infections, Male, Peritonitis, Rats, Rats, Sprague-Dawley, Signal Transduction, Smad7 Protein, Transforming Growth Factor beta.
user
Does impaired TGF-beta signalling enhance peritoneal inflammation induced by E. coli in rats? Context: Peritonitis is a common and severe complication of peritoneal dialysis (PD). Although TGF-beta is a key mediator in peritoneal fibrosis with chronic PD, its role in acute peritoneal inflammation remains unclear. Potential role of TGF-beta signalling in acute peritonitis was investigated in a rat model by infecting peritoneum with E. coli and in primary culture of peritoneal mesothelial cells (PMC) by LPS. We found that a single infection of E. coli caused an acute, but transient peritonitis by a significant increase in ascites white blood cells (WBC), peritoneal CD45+ leukocytes, upregulation of TNFalpha, activation of NF-kappaB/p65 and impaired peritoneal function (all P < 0.01). Interestingly, spontaneous recovery of acute peritonitis occurred with upregulation of TGF-beta1 and activation of Smad2/3, suggesting a protective role of TGF-beta signalling in acute peritonitis. This was demonstrated by the finding that blockade of the TGF-beta signalling pathway with gene transfer of Smad7 inactivated peritoneal Smad2/3 but worsened E. coli-induced, NF-kappaB-dependent peritoneal inflammation and peritoneal dysfunction (all P < 0.01). Furthermore, studies in vitro also found that impaired TGF-beta signalling by overexpressing Smad7 in PMC were able to overcome the inhibitory effect of TGF-beta on LPS-induced, NF-kappaB-mediated peritoneal inflammation.
assistant
Results from this study demonstrate that TGF-beta signalling is essential in protection against acute peritoneal inflammation induced by bacterial infection. Final Decision: yes