TGF-β 1 enhances neurite outgrowth via regulation of proteasome function and EFABP
TGF-β 1 enhances neurite outgrowth via regulation of proteasome function and EFABP
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DOI：
10.1016/j.nbd.2010.02.011
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发表时间：
2010-06-01
影响因子：
6.1
通讯作者：
Lingor, Paul
中科院分区：
文献类型：
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作者：
Knoeferle, Johanna;Ramljak, Sanja;Lingor, Paul
泛素-蛋白酶体系统的功能障碍已经被认为是聚集相关疾病（例如帕金森病）的发病机制中的致病因素。我们在这里表明，转化生长因子-β 1（TGF-β），多功能细胞因子和多巴胺能（DA能）神经元的营养因子调节蛋白酶体功能的主要中脑神经元。TGF-β差异抑制蛋白酶体亚活性，其中肽基-谷氨酰肽水解样亚活性和胰凝乳蛋白酶样亚活性的时间依赖性抑制最为显著。DA能亚群中蛋白酶体活性的调节可以特异性定量。蛋白质印迹分析揭示了TGF-β处理后泛素化蛋白的积累。通过2D-凝胶电泳和质谱进一步分析这些富集蛋白的身份。我们发现表皮脂肪酸结合蛋白（EFABP）强烈增加和泛素化后TGF-β治疗，并证实了这一发现的免疫共沉淀。虽然应用TGF-β增加了划痕损伤模型中的神经突再生，但siRNA下调EFABP显著降低了这种作用。因此，我们假设，蛋白酶体功能的差异调节，如TGF-β所示，可以导致蛋白质的富集，如EFABP，介导生理功能，如神经突再生。(C)2010年爱思唯尔公司All rights reserved.
Malfunction of the ubiquitin-proteasome system has been implicated as a causal factor in the pathogenesis of aggregation-related disorders, e.g. Parkinson's disease. We show here that Transforming growth factor-beta 1 (TGF-beta), a multifunctional cytokine and trophic factor for dopaminergic (DAergic) neurons modulates proteasome function in primary midbrain neurons. TGF-beta differentially inhibited proteasomal subactivities with a most pronounced time-dependent inhibition of the peptidyl-glutamyl peptide hydrolyzing-like and chymotrypsin-like subactivity. Regulation of proteasomal activity could be specifically quantified in the DAergic subpopulation. Protein blot analysis revealed an accumulation of ubiquitinated proteins after TGF-beta treatment. The identity of these enriched proteins was further analyzed by 2D-gel electrophoresis and mass spectrometry. We found epidermal fatty acid binding protein (EFABP) to be strongly increased and ubiquitinated after TGF-beta treatment and confirmed this finding by co-immunoprecipitation. While application of TGF-beta increased neurite regeneration in a scratch lesion model, downregulation of EFABP by siRNA significantly decreased this effect. We thus postulate that a differential regulation of proteasomal function, as demonstrated for TGF-beta, can result in an enrichment of proteins, such as EFABP, that mediate physiological functions, such as neurite regeneration. (C) 2010 Elsevier Inc. All rights reserved.