Effect of lipopolysaccharide on Wallerian degeneration after peripheral nerve injury in rats
10.3969/j.issn.1005-4847.2017.02.018
- VernacularTitle:脂多糖干预对大鼠周围神经损伤后瓦勒变性的影响
- Author:
Le XIONG
;
Qian ZHANG
;
Ruowu SHEN
;
Honglin BIAN
;
Guangqiang SUN
;
Yi WANG
;
Fengyu ZHANG
;
Bei ZHANG
- Keywords:
Peripheral nerve;
Wallerian degeneration;
Lipopolysaccharide;
Myelin debris
- From:
Acta Laboratorium Animalis Scientia Sinica
2017;25(2):211-217
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the effects of lipopolysaccharide(LPS) on myelin phagocytosis during Wallerian degeneration after early peripheral nerve injury in rats.Methods Fifty male Wistar rats were recruited and randomly divided into LPS group(n=20),model group(n=20) and sham group(n=10).The right sciatic nerves of rats in the LPS and model groups were cut and sutured end-to-end,while the sciatic nerve of sham group rats were only exposed.Immediately after surgery,the rats in LPS group were given microinjections of LPS(2 g/L) into the surgical site in a final volume of 1 μL,and the rats in other two groups were injected with the same volume of saline.The sciatic nerves were taken at 1.5 h,24 h and 7d after surgery.Real-time quantitative PCR(qRT-PCR) was applied to detect the dynamic expressions of IL-1β mRNA and MCP-1 mRNA.Immunofluorescence staining was used to test the expression of CD68+ macrophages in sciatic nerves.HE staining was used to observe the pathological alterations of sciatic nerves tissue.ORO staining was used to observe sciatic nerves demyelination.LFB staining was used to detect the sciatic nerves myelin.Sciatic function index was used to evaluate the recovery of motor function in rats.Results Compared with the model group,qRT-PCR indicated that the expression of IL-1β and MCP-1 from LPS group were increased at 1.5 h and 24 h after surgery(P<0.001, P<0.001),respectively.Compared with the model group,the expression of CD68+ cells was increased significantly at 7th day after surgery(P<0.05).Histological examination showed that compared with the model group,a lot of inflammatory cells and Schwann cells were found at sciatic nerve stump in the LPS group at 7th day after operation.ORO staining showed that the degree of demyelination in the LPS group was higher than that in the model group.LFB staining showed that the sciatic nerve stump demyelination appeared in both model group and the LPS group at 7th day after operation,but compared with the model group,myelin debris clearance in the LPS group was significantly accelerated(P<0.05).Finally,compared with the model group,the SFI in the LPS group was increased significantly at 20 d after surgery(P<0.05).Conclusions The results confirm that LPS is possible to manipulate the innate immune response to accelerate myelin clearance during Wallerian degeneration after early peripheral nerve injury in rats.
