中国神经再生研究(英文版) ›› 2015, Vol. 10 ›› Issue (10): 1578-1580.doi: 10.4103/1673-5374.165228

• 观点:脑损伤修复保护与再生 • 上一篇    下一篇

转化生长因子β1对小胶质细胞中的抗炎效应

  

  • 收稿日期:2015-07-10 出版日期:2015-10-28 发布日期:2015-10-28

Transforming growth factor β1-mediated anti-inflammation slows progression of midbrain dopaminergic neurodegeneration in Parkinson’s disease?

Björn Spittau*   

  1. Institute of Anatomy and Cell Biology, Department of Molecular Embryology, Albert-Ludwigs-University Freiburg, Freiburg im Breisgau, Germany
  • Received:2015-07-10 Online:2015-10-28 Published:2015-10-28
  • Contact: Bj?rn Spittau, M.D.,bjoern.spittau@anat.uni-freiburg.de.

摘要:

大多数帕金森病例属于自发发展,尽管已有该方向的大量研究,但关于中脑多巴胺能神经元退变的分子机制仍未得到很好地解释。有趣的是,几乎所有帕金森病例的共同特征都是神经炎症响应,主要由小胶质细胞介导中枢神经系统固有免疫细胞的反应。在帕金森病的动物模型和人类病患中,小胶质细胞已表现出其采用活化和反应性表型特征的促炎性基因,这会进一步威胁和刺激中脑多巴胺能神经元,并驱动神经退变的进展。在能够调节小胶质细胞激活状态的内源性因素中,转化生长因子β1已被证明是体内和体外最有效的因素之一。在生理条件下,转化生长因子β1主要由神经元和胶质纤维酸性蛋白胶质细胞在整个中枢神经系统中进行较小程度上的表达。这种表达模式表明,神经元衍生的转化生长因子β1在生理条件下对保持小胶质细胞体内平衡或许是十分重要的。事实上,Butovsky和他的同事在2014年已有报道,如果中枢神经系统缺乏转化生长因子β1将会导致小胶质细胞的功能和形态损伤。目前仍有待建立神经元衍生的转化生长因子β1在小胶质保护中是否是必须的,以及转化生长因子β1缺失的造成的周围作用是否对小胶质细胞表型造成影响?

Abstract:

Parkinson´s disease (PD) is characterized by the progressive loss of midbrain dopaminergic (mDA) neurons and a subsequent decrease in striatal dopamine levels which cause the typical clinical motor symptoms such as muscle rigidity, bradykinesia and tremor. Although a subset of PD cases has been described to arise from inherited mutations of genes such as α-Synuclein or Lrkk2, the majority of PD cases develop spontaneously. Despite intensive research, the molecular mechanisms underlying degeneration of mDA neurons are only poorly understood. Interestingly, a common hallmark of virtually all PD cases is a neuroinflammatory response that is predominantly mediated by microglia - the resident immune cells of the central nervous system (CNS). Among the endogenous factors that are capable of regulating microglia activation states, Transforming growth factor β1 (TGFβ1) has been shown to be one of the most potent factors in vivo and in vitro. TGFβ1 immunoreactivity is detectable in midbrain neurons but not in microglia which extend their processes towards TGFβ1-positive midbrain neurons and are located in close proximity to these neurons. This expression pattern suggests, that neuron-derived TGFβ1 might be important to maintain microglia homeostasis under physiological conditions. Indeed, Butovsky and colleagues (2014) have reported that lack of TGFβ1 in the CNS resulted in functional and morphological impairment of microglia. However, it has to be mentioned that the authors used TGFβ1-deficient mice which were crossed to mice expressing TGFβ1 under the control of the IL2-promoter. This approach prevents the lethal postnatal phenotype of TGFβ1-/- mice, which die due to a systemic inflammation mediated by T cells. It remains to be established whether neuron-derived TGFβ1 is essential to mediate microglia maintenance or whether peripheral effects of TGFβ1-deletion are responsible for the microglia phenotype observed by Butovsky et al. (2014).