Figure 5.

(A) Assessments of in vitro TNF-α mRNA stability in isolated tubules harvested after in vivo LPS injection. Proximal tubules from control (C) mice and LPS-PC mice (PC) were harvested 30 min after either LPS or vehicle injection, and they were incubated in vitro for 3 or 6 h with or without actinomycin D (AD). Tubules from PC mice that were rechallenged with LPS manifested decreased mRNA degradation, as assessed at either the 3- or 6-h time point. Conversely, neither preconditioning alone nor LPS injection alone altered TNF-α mRNA degradation rates. (B) Assessments of in vitro MCP-1 and HO-1 stability after intravenous LPS injection. LPS induced MCP-1 mRNA stability, whether the assessments were made at 30 min or 18 h (preconditioned mice) after LPS injection. Conversely, only a minimal increase in HO-1 mRNA stability was observed in response to LPS, and this was observed only in preconditioned tubules that were rechallenged with LPS (P < 0.01).