BackgroundInfection is a common cause of acute lung injury (ALI). This study was aimed to explore whether Toll-like receptors 4 (TLR4) of airway smooth muscle cells (ASMCs) play a role in lipopolysaccharide (LPS)-induced airway hyperresponsiveness and potential mechanisms.Methods In vivo: A sensitizing dose of LPS (50 µg) was administered i.p. to female mice before anesthesia with either 3% sevoflurane or phenobarbital i.p. After stabilization, the mice were challenged with 5 µg of intratracheal LPS to mimic inflammatory attack. The effects of sevoflurane were assessed by measurement of airway responsiveness to methacholine, histological examination, and IL-1, IL-6, TNF-α levels in bronchoalveolar lavage fluid (BALF). Protein and gene expression of TLR4 and NF-κB were also assessed. In vitro: After pre-sensitization of ASMCs and ASM segments for 24h, levels of TLR4 and NF-κB proteins in cultured ASMCs were measured after continuous LPS exposure for 1, 3, 5, 12 and 24h in presence or absence of sevoflurane. Constrictor and relaxant responsiveness of ASM was measured 24 h afterwards.ResultsThe mRNA and protein levels of NF-κB and TLR4 in ASM were increased and maintained at high level after LPS challenge throughout 24h observation period, both in vivo and in vitro. Sevoflurane reduced LPS-induced airway hyperresponsiveness, lung inflammatory cell infiltration and proinflammatory cytokines release in BALF as well as maximal isometric contractile force of ASM segments to acetylcholine, but it increased maximal relaxation response to isoproterenol. Treatment with specific NF-κB inhibitor produced similar protections as sevoflurane, including decreased expressions of TLR4 and NF-κB in cultured ASMCs and improved pharmacodynamic responsiveness of ASM to ACh and isoproterenol.ConclusionsThis study demonstrates the crucial role of TLR4 activation in ASMCs during ALI in response to LPS. Sevoflurane exerts direct relaxant and anti-inflammatory effects in vivo and in vitro via inhibition of TLR4/NF-κB pathway.

Targeting angiogenesis is considered an effective strategy for treating the expansion and metastasis of tumors. The aim of this study is to assess the effects of perifosine, an inhibitor of Akt, on cell proliferation, apoptosis, angiogenesis, and VEGF-induced cell migration in cultured human umbilical vein endothelial cells (HUVECs) in vitro. MTT and cell cycle analysis results indicated that perifosine inhibited the growth of HUVECs in a dose-dependent manner, arrested cell cycle progression at the G(2) phase with regulation the expression of p21 and cyclinB1. Apoptosis induced by the higher concentrations of perifosine in HUVECs was also observed. In addition, tube formation of HUVECs and VEGF-induced cell migration were markedly inhibited by perifosine. Western blotting analysis of cell signaling molecules indicated that perifosine inhibited ERK and p38 phosphorylation in HUVECs. These results suggest that perifosine exerts anti-angiogenic activity in HUVECs and is a promising agent for treatment of angiogenesis related-diseases.