YKL-40 (Chitinase 3-like I) is expressed in a subset of astrocytes in Alzheimer’s disease and other tauopathies

Journal of Neuroinflammation

Jordi Clarimon¹  Alberto Lleó¹  Jordi Pegueroles¹  Carla San Martín-Paniello¹  Juan Fortea¹  Marta Querol-Vilaseca¹  Martí Colom-Cadena¹  Olivia Belbin¹ 

[1] Memory Unit, Department of Neurology, Institut d’Investigacions Biomèdiques Sant Pau - Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona;

关键词: YKL-40;    Alzheimer’s disease;    Tauopathies;    Tau;    Astrocytes;    Neuroinflammation;   

DOI  :  10.1186/s12974-017-0893-7

来源: DOAJ

【 摘 要 】

Abstract Background The innate immune system is known to be involved early in the pathogenesis of Alzheimer’s disease (AD) and other neurodegenerative disorders. The inflammatory response in the central nervous system can be measured postmortem or through a series of inflammatory mediator surrogates. YKL-40 (also named Chitinase-3-like I) has been frequently investigated in body fluids as a surrogate marker of neuroinflammation in AD and other neurological disorders. However, the expression pattern of YKL-40 in the human brain with neurodegenerative pathology remains poorly investigated. Our aim was to study the cellular expression pattern of YKL-40 in the brain of patients with clinical and neuropathological criteria for AD (n = 11); three non-AD tauopathies: Pick’s disease (PiD; n = 8), corticobasal degeneration (CBD; n = 8) and progressive supranuclear palsy (PSP; n = 9) and a group of neurologically healthy controls (n = 6). Methods Semiquantitative neuropathological evaluation and quantitative confocal triple immunofluorescence studies were performed. An in-house algorithm was used to detect and quantify pathology burden of random regions of interest on a full tissue-section scan. Kruskal-Wallis and Dunn’s multiple comparison tests were performed for colocalization and quantification analyses. Results We found that brain YKL-40 immunoreactivity was observed in a subset of astrocytes in all four diseases and in controls. There was a strong colocalization between YKL-40 and the astroglial marker GFAP but not with neuronal nor microglial markers. Intriguingly, YKL-40-positive astrocytes were tau-negative in PSP, CBD and PiD. The number of YKL-40-positive astrocytes was increased in tauopathies compared with that in controls. A positive correlation was found between YKL-40 and tau immunoreactivities. Conclusions This study confirms that YKL-40 is expressed by a subset of astrocytes in AD and other tauopathies. YKL-40 expression is elevated in several neurodegenerative conditions and correlates with tau pathology.

【 授权许可】

Unknown