Dal Prà Ilaria, Chiarini Anna, Gui Li, Chakravarthy Balu, Pacchiana Raffaella, Gardenal Emanuela, Whitfield James F, Armato Ubaldo
Department of Life & Reproduction Sciences, The University of Verona Medical School, Verona, Italy.
Department of Neurology, Southwest Hospital, Third Military Medical University, Chongqing, China.
Neuroscientist. 2015 Feb;21(1):9-29. doi: 10.1177/1073858414529828. Epub 2014 Apr 16.
Evidence has begun emerging for the "contagious" and destructive Aβ42 (amyloid-beta42) oligomers and phosphorylated Tau oligomers as drivers of sporadic Alzheimer's disease (AD), which advances along a pathway starting from the brainstem or entorhinal cortex and leading to cognition-related upper cerebral cortex regions. Seemingly, Aβ42 oligomers trigger the events generating the neurotoxic Tau oligomers, which may even by themselves spread the characteristic AD neuropathology. It has been assumed that only neurons make and spread these toxic drivers, whereas their associated astrocytes are just janitorial bystanders/scavengers. But this view is likely to radically change since normal human astrocytes freshly isolated from adult cerebral cortex can be induced by exogenous Aβ25-35, an Aβ42 proxy, to make and secrete increased amounts of endogenous Aβ42. Thus, it would seem that the steady slow progression of AD neuropathology along specific cognition-relevant brain networks is driven by both Aβ42 and phosphorylated Tau oligomers that are variously released from increasing numbers of "contagion-stricken" members of tightly coupled neuron-astrocyte teams. Hence, we surmise that stopping the oversecretion and spread of the two kinds of "contagious" oligomers by such team members, perhaps via a specific CaSR (Ca(2+)-sensing receptor) antagonist like NPS 2143, might effectively treat AD.
有证据开始表明,具有“传染性”和破坏性的β淀粉样蛋白42(Aβ42)寡聚体和磷酸化Tau寡聚体是散发性阿尔茨海默病(AD)的驱动因素,AD沿着从脑干或内嗅皮质开始并通向与认知相关的大脑皮质上层区域的途径发展。似乎,Aβ42寡聚体引发了产生神经毒性Tau寡聚体的事件,而Tau寡聚体自身甚至可能传播AD的特征性神经病理学变化。一直以来人们认为只有神经元产生并传播这些毒性驱动因素,而与之相关的星形胶质细胞只是旁观者/清除者。但这种观点可能会发生根本性改变,因为从成人脑皮质新分离出的正常人类星形胶质细胞可被Aβ42的替代物外源性Aβ25 - 35诱导,从而产生并分泌更多内源性Aβ42。因此,AD神经病理学沿着特定认知相关脑网络的稳定缓慢进展似乎是由Aβ42和磷酸化Tau寡聚体共同驱动的,这些寡聚体从紧密耦合的神经元 - 星形胶质细胞团队中越来越多的“受感染”成员中以不同方式释放出来。因此,我们推测,通过这样的团队成员,或许借助像NPS 2143这样的特定钙敏感受体(CaSR,Ca(2 +)-sensing receptor)拮抗剂来阻止这两种“传染性”寡聚体的过度分泌和传播,可能会有效治疗AD。