脂筏在GDNF与其受体相互作用中的意义

The role of lipid rafts in the interaction between GDNF and its receptors

目的:探讨脂筏对于GDNF与其膜受体相互作用的影响。方法:MN9D细胞和SD大鼠随机分成三组:GDNF组、PBS组、空白对照组。两种方式处理三组样品:破坏和不破坏细胞膜上的脂筏。通过免疫共沉淀和免疫印迹检测破坏脂筏前后GDNF及其配体结合受体GFRα1与四种膜受体(RET,NCAM140,integrinβ1和N-cadherin)之间的结合情况。结果:细胞膜上的脂筏未被破坏前,四种膜受体都能够与GDNF结合发生免疫共沉淀。脂筏被破坏后,GDNF只能与RET和N-cadherin结合发生免疫共沉淀,并且这种结合在GDNF组中最多;而GFRα1只能和RET结合发生免疫共沉淀。结论:膜受体介导的GDNF生物学作用均可发生在脂筏这一平台上,脂筏在GDNF与其受体相互作用中扮演着重要角色。

Objective： To investigate the effects of lipid rafts in the interaction between GDNF and its membrane recep- tors. Methods： MN9D cells and SD rats were randomly divided into three groups： GDNF group, PBS group, Control group. Samples of three groups were treated with two ways ： to disintegrate the lipid rafts on the cell membrane or not. Through co-immunoprecipitation and western blotting to detect the binding of GDNF or its ligand-binding receptor GFRα1 to four receptors （RET, NCAM140, integrinβ1, N-cadherin） before and after the lipid rafts were disintegrated. Results： Before the lipid rafts on the cell membrane were disintegrated, GDNF could bind to four receptors resulting in co-immuno- precipitation. After the lipid rafts were disintegrated, GDNF only could bind to RET and N-cadherin result in co-immuno- precipitation, which were highest of GDNF group. In addition, GFRα1 only could bind to RET resulting in co-immuno- precipitation. Conclusion： Our study strongly suggests the receptor-mediated biological effects of GDNF can take place on the platform of lipid rafts which play a substantial role in the interaction between GDNF and its receptors.