Objective To explore whether lipoxin A4 (LXA4)could prevent lipopolysaccharide (LPS)-induced human umbilical vein endothelial cells (HUVEC) monolayer hyperpermeability and its possible mechanism. Methods Human umbilical cords were obtained from women with normal pregnancy immediately after delivery from Tongji Hospital Affiliated of Tongji Medical College. Primary HUVEC were isolated from umbilical veins and subcultured, then, HUVEC were divided into four groups:control group;LPS group (10 mg/L of LPS); LPS + LXA4 group(10 mg/L of LPS and 100 nmol/L of LXA4); LPS +LXA4 + BOC-2 group [10 μmol/L of BOC-2, an effective antagonist of formyl peptide receptor like 1 (FPRL-1)]. All expriments were performed after cells were treated for 24 hours. Endothelial permeability was measured by fluorescein isothiocyan-ate labelled bovine serum albumin (FITC-BSA) clearance across the monolayer; tumor necrosis factor α(TNF-o) mRNA and secretion were detected by reverse transcriplase (RT) -PCR and ELISA assay respectively, and nuclear factor κB(NF-κB) protein change was determined by western blot. Results (1) LPS induced a significant increase in the permeability [Pa value of LPS group was (183.1 ±1.7)%], while co-administrating with LXA4 obviously attenuated this LPS-induced hyperpermeability, Pa value of LPS + LXA4 group was (103.1 ±2.2)%, LPS + LXA4 + BOC-2 group was (162.2 ± 2.8)%, control group was 100%, the permeability of HUVEC monolayer was significantly increased by LPS which was (83.1 ± 1.7)% of control (P <0.01), however, it was notably inhibited by LXA4 (P<0.05); the blockade of FPRL-1 could attenuate the effect of LXA4, that is, there was no difference between the LPS + LXA4 + BOC-2 group and the LPS group. (2) After treatment with different concentration of LPS(0,0.1, 1,10 mg/L), the mRNA expressions of TNF-α were increased (1.11 ±0.11,1.27 ± 0.03, 1.60 ± 0.06, 1.82 ± 0. 04, respectively), compared with the control group, at the concentration of 1,10 mg/L LPS, the difference was statistically significant (P<0. 05). (3) The increased levels of NF-κB and inflammatory mediator TNF-α in the LPS group were both inhibited by LXA4. Levels of NF-κB protein and TNF-o mRNA secretion in LPS treated group (0.53 ±0.06 and 0.81 ±0.09 ,respectively)were both inhibited by LXA4 (0.19 ± 0.05 and 0.41 ± 0.07, respectively, and both had significant difference, P<0.05). (4) Levels of TNF-α in HUVEC culture medium of LPS group [(31.94 ±0.01)ng/L] was significantly higher than the control group [(18.17 ± 0.03) ng/L, P<0.05], LPS + LXA4 group [(15.72 ± 0.07) ng/L] was significantly lower than the LPS group (P<0.05). Conclusion Our findings demonstrated that LXA4 could prevent the endothelial cell hyperpermeability induced by LPS in HUVEC under which the possible mechanism was through inhibiting the expression of NF-κB and its related cytokines through receptor-dependent.

Preventive treatment of diseases is a traditional Chinese medicine (TCM) concept that conforms to the demand of modern healthcare emphasizing prevention. This concept, however, calls for close and orderly collaboration between general hospitals and primary community healthcare institutions, in order to encourage coordinated regional development. The authors described the new healthcare mode of " One Center, One Platform, and One Network" jointly built and run by Dongguan Municipal Health Bureau and Dongguan TCM Hospital. This practice has pioneered a full-range, closed-loop and one-stop service chain featuring preventive treatment. Such an innovative TCM health management system has realized information interconnection of preventive treatment, and upgraded the capacity and effectiveness of community medical services, hence expanding the number of beneficiaries.