YKL-40 as a Potential Biomarker and a Possible Target in Therapeutic Strategies of Alzheimer's Disease.
BACKGROUND
Growing body of evidence suggests that the pathogenesis of Alzheimer's disease (AD), a progressing neurodegenerative condition, is not limited to the neuronal compartment, but also involves various immunological mechanisms. Insoluble Aβ aggregates in the brain can induce the activation of microglia, resulting in the synthesis of proinflammatory mediators, which further can stimulate astrocytic expression of YKL-40. Therefore, the aim of the current review is to present up-to-date data about the role of YKL-40 as a biomarker of AD as well as the possibility of therapeutic strategies targeting neuroinflammation.


OBJECTIVE
We searched PubMed articles for the terms "YKL-40", "neurodegeneration", "neuroinflammation" and "Alzheimer's disease", and included papers focusing on this review's scope.


RESULTS
Recent studies indicate that CSF concentrations of YKL-40 were significantly higher in AD patients than in cognitively normal individuals and correlated with dementia biomarkers, such as tau proteins and amyloid beta. Determination of YKL-40 CSF concentration may be also helpful in differentiation between types of dementia and in the distinction of patients in the stable phase of MCI from those who progressed to dementia. Moreover, significantly increased levels of YKL-40 mRNA were found in AD brains in comparison with non-demented controls. Additionally, it was suggested that anti-inflammatory treatment might relief the symptoms of AD and slow its progression.


CONCLUSIONS
Based on the recent knowledge, YKL-40 might be useful as a possible biomarker in the diagnosis and prognosis of AD. Modulation of risk factors and targeting of immune mechanisms, including systemic inflammation could lead to future preventive or therapeutic strategies for AD.
Department of Neurodegeneration Diagnostics, Medical University of Białystok, Białystok, Poland.
Paweł
P
Muszyński
Department of Biochemical Diagnostics, University Hospital in Białystok, Białystok, Poland.
Magdalena
M
Groblewska
Department of Neurodegeneration Diagnostics, Medical University of Białystok, Białystok, Poland.
Agnieszka
A
Kulczyńska-Przybik
Department of Neurology, Medical University of Białystok, Białystok, Poland.
Alina
A
Kułakowska
Department of Neurodegeneration Diagnostics, Medical University of Białystok, Białystok, Poland.
Barbara
B
Mroczko
D000544:Alzheimer Disease / Q000188:drug therapy* / Q000378:metabolism*; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D000071451:Chitinase-3-Like Protein 1 / Q000378:metabolism*; D006801:Humans
D015415:Biomarkers; D000071451:Chitinase-3-Like Protein 1
Alzheimer's disease; YKL-40; biomarkers; dementia; neurodegeneration; neuroinflammation