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The effect of Lipoxin A4 on the interaction between macrophage and osteoblast: possible role in the treatment of aseptic loosening.

Li G, Wu P, Xu Y, Yu Y, Sun L, Zhu L, Ye D - BMC Musculoskelet Disord (2009)

Bottom Line: Exogenous 0-100 nM LXA4 presented an inhibitory effect on both generation of above cytokines and PMMA stimulated calvarial bone resorption with a dose-dependent manner.LXA4 in supernatant from neither rest macrophages nor macrophages cultured alone exposing to PMMA was detectable.In the present study, we demonstrated that LXA4 had a favorable inhibitory effect on PMMA-induced inflammation in a macrophage and OB co-culture system.

View Article: PubMed Central - HTML - PubMed

Affiliation: 1Department of surgery, Liyuan Hospital, Huazhong University of Science and Technology, Wuhan, PR China. lg30003000@yahoo.com.cn

ABSTRACT

Background: Aseptic loosening (AL) is the main problem of total joints replacement (TJR) by the implantation of permanently prosthetic components. In vitro and in vivo studies have clearly demonstrated that wear debris and its byproducts could trigger inflammation in the peri-implant tissue. Lipoxins (LXs) are endogenous eicosanoids synthesized locally from arachidonate acid (AA) at sites of inflammation and mediate pro-resolving activity. A number of studies have demonstrated the effect of LXA4 to counteract inflammation in different cell and animal models, but till now, no relative report about the role of LXs in progress or prevention of AL.

Methods: Murine RAW264.7 macrophage cell line and MC3T3-E1 osteoblasts (OB) cell line were purchased. Co-cultured model of these two cell lines was established. To explore the effect of exogenous Lipoxin A4 (LXA4) on polymethylmethacrylate (PMMA) induced inflammation, pro-inflammatory cytokines including TNF-alpha, IL-1beta, PGE2 and GM-CSF were measured by ELISA kits and bone resorption was quantified by measuring calcium release from 5-day-old mice calvaria in vitro. To determine further the endogenous effect of LXA4, cells were co-cultured and with or without 15-lipoxygease (15-LO) blocking by 15-LO siRNA. Both real-time PCR and western blotting were applied to confirm the inhibitory efficiency of 15-LO by siRNA.

Results: 0.1 mg/ml, 0.5 mg/ml and 1.0 mg/ml PMMA showed a time-dependent manner to trigger production of all the pro-inflammatory cytokines studied. Exogenous 0-100 nM LXA4 presented an inhibitory effect on both generation of above cytokines and PMMA stimulated calvarial bone resorption with a dose-dependent manner. LXA4 in supernatant from neither rest macrophages nor macrophages cultured alone exposing to PMMA was detectable. In co-cultured cells challenged by PMMA, LXA4 was increased significantly, while, this enhance could be partly inhibited by 15-LO siRNA. When LXA4 generation was blocked with 15-LO siRNA, the PMMA induced pro-inflammatory cytokines were elevated and bone resorption was accelerated.

Conclusion: In the present study, we demonstrated that LXA4 had a favorable inhibitory effect on PMMA-induced inflammation in a macrophage and OB co-culture system.

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Effect of endogenous LXA4 on PMMA induced bone resorption. **, P < 0.01 compared to Mφ group; #, P < 0.05 compared to Mφ+OB+PMMA group; ##, P < 0.05 compared to Mφ+PMMA group.
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Figure 6: Effect of endogenous LXA4 on PMMA induced bone resorption. **, P < 0.01 compared to Mφ group; #, P < 0.05 compared to Mφ+OB+PMMA group; ##, P < 0.05 compared to Mφ+PMMA group.

Mentions: Because increase of pro-inflammatory cytokines paralleled bone resorption in both AL patients and our above results[30], we next examined the contribution of endogenous LXA4 to PMMA induced bone resorption. The data showed that 15-LO siRNA significantly accelerated the bone resorption (Fig. 6, P < 0.05). Very interesting, we also found that after PMMA stimulation, media from co-cultured cells lead to obviously higher calcium content than media from macrophages cultured alone (Fig. 6, P < 0.05).


The effect of Lipoxin A4 on the interaction between macrophage and osteoblast: possible role in the treatment of aseptic loosening.

Li G, Wu P, Xu Y, Yu Y, Sun L, Zhu L, Ye D - BMC Musculoskelet Disord (2009)

Effect of endogenous LXA4 on PMMA induced bone resorption. **, P < 0.01 compared to Mφ group; #, P < 0.05 compared to Mφ+OB+PMMA group; ##, P < 0.05 compared to Mφ+PMMA group.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2698870&req=5

Figure 6: Effect of endogenous LXA4 on PMMA induced bone resorption. **, P < 0.01 compared to Mφ group; #, P < 0.05 compared to Mφ+OB+PMMA group; ##, P < 0.05 compared to Mφ+PMMA group.
Mentions: Because increase of pro-inflammatory cytokines paralleled bone resorption in both AL patients and our above results[30], we next examined the contribution of endogenous LXA4 to PMMA induced bone resorption. The data showed that 15-LO siRNA significantly accelerated the bone resorption (Fig. 6, P < 0.05). Very interesting, we also found that after PMMA stimulation, media from co-cultured cells lead to obviously higher calcium content than media from macrophages cultured alone (Fig. 6, P < 0.05).

Bottom Line: Exogenous 0-100 nM LXA4 presented an inhibitory effect on both generation of above cytokines and PMMA stimulated calvarial bone resorption with a dose-dependent manner.LXA4 in supernatant from neither rest macrophages nor macrophages cultured alone exposing to PMMA was detectable.In the present study, we demonstrated that LXA4 had a favorable inhibitory effect on PMMA-induced inflammation in a macrophage and OB co-culture system.

View Article: PubMed Central - HTML - PubMed

Affiliation: 1Department of surgery, Liyuan Hospital, Huazhong University of Science and Technology, Wuhan, PR China. lg30003000@yahoo.com.cn

ABSTRACT

Background: Aseptic loosening (AL) is the main problem of total joints replacement (TJR) by the implantation of permanently prosthetic components. In vitro and in vivo studies have clearly demonstrated that wear debris and its byproducts could trigger inflammation in the peri-implant tissue. Lipoxins (LXs) are endogenous eicosanoids synthesized locally from arachidonate acid (AA) at sites of inflammation and mediate pro-resolving activity. A number of studies have demonstrated the effect of LXA4 to counteract inflammation in different cell and animal models, but till now, no relative report about the role of LXs in progress or prevention of AL.

Methods: Murine RAW264.7 macrophage cell line and MC3T3-E1 osteoblasts (OB) cell line were purchased. Co-cultured model of these two cell lines was established. To explore the effect of exogenous Lipoxin A4 (LXA4) on polymethylmethacrylate (PMMA) induced inflammation, pro-inflammatory cytokines including TNF-alpha, IL-1beta, PGE2 and GM-CSF were measured by ELISA kits and bone resorption was quantified by measuring calcium release from 5-day-old mice calvaria in vitro. To determine further the endogenous effect of LXA4, cells were co-cultured and with or without 15-lipoxygease (15-LO) blocking by 15-LO siRNA. Both real-time PCR and western blotting were applied to confirm the inhibitory efficiency of 15-LO by siRNA.

Results: 0.1 mg/ml, 0.5 mg/ml and 1.0 mg/ml PMMA showed a time-dependent manner to trigger production of all the pro-inflammatory cytokines studied. Exogenous 0-100 nM LXA4 presented an inhibitory effect on both generation of above cytokines and PMMA stimulated calvarial bone resorption with a dose-dependent manner. LXA4 in supernatant from neither rest macrophages nor macrophages cultured alone exposing to PMMA was detectable. In co-cultured cells challenged by PMMA, LXA4 was increased significantly, while, this enhance could be partly inhibited by 15-LO siRNA. When LXA4 generation was blocked with 15-LO siRNA, the PMMA induced pro-inflammatory cytokines were elevated and bone resorption was accelerated.

Conclusion: In the present study, we demonstrated that LXA4 had a favorable inhibitory effect on PMMA-induced inflammation in a macrophage and OB co-culture system.

Show MeSH
Related in: MedlinePlus