YKL-40 in the brain and cerebrospinal fluid of neurodegenerative dementias.

Abstract

BACKGROUND:

YKL-40 (also known as Chitinase 3-like 1) is a glycoprotein produced by inflammatory, cancer and stem cells. Its physiological role is not completely understood but YKL-40 is elevated in the brain and cerebrospinal fluid (CSF) in several neurological and neurodegenerative diseases associated with inflammatory processes. Yet the precise characterization of YKL-40 in dementia cases is missing.

METHODS:

In the present study, we comparatively analysed YKL-40 levels in the brain and CSF samples from neurodegenerative dementias of different aetiologies characterized by the presence of cortical pathology and disease-specific neuroinflammatory signatures.

RESULTS:

YKL-40 was normally expressed in fibrillar astrocytes in the white matter. Additionally YKL-40 was highly and widely expressed in reactive protoplasmic cortical and perivascular astrocytes, and fibrillar astrocytes in sporadic Creutzfeldt-Jakob disease (sCJD). Elevated YKL-40 levels were also detected in Alzheimer's disease (AD) but not in dementia with Lewy bodies (DLB). In AD, YKL-40-positive astrocytes were commonly found in clusters, often around β-amyloid plaques, and surrounding vessels with β-amyloid angiopathy; they were also distributed randomly in the cerebral cortex and white matter. YKL-40 overexpression appeared as a pre-clinical event as demonstrated in experimental models of prion diseases and AD pathology. CSF YKL-40 levels were measured in a cohort of 288 individuals, including neurological controls (NC) and patients diagnosed with different types of dementia. Compared to NC, increased YKL-40 levels were detected in sCJD (p < 0.001, AUC = 0.92) and AD (p < 0.001, AUC = 0.77) but not in vascular dementia (VaD) (p > 0.05, AUC = 0.71) or in DLB/Parkinson's disease dementia (PDD) (p > 0.05, AUC = 0.70). Further, two independent patient cohorts were used to validate the increased CSF YKL-40 levels in sCJD. Additionally, increased YKL-40 levels were found in genetic prion diseases associated with the PRNP-D178N (Fatal Familial Insomnia) and PRNP-E200K mutations.

CONCLUSIONS:

Our results unequivocally demonstrate that in neurodegenerative dementias, YKL-40 is a disease-specific marker of neuroinflammation showing its highest levels in prion diseases. Therefore, YKL-40 quantification might have a potential for application in the evaluation of therapeutic intervention in dementias with a neuroinflammatory component.

• Authors: Franc Llorens, Katrin Thüne, Waqas Tahir, Eirini Kanata, Daniela Diaz-Lucena, Konstantinos Xanthopoulos, Eleni Kovatsi, Catharina Pleschka, Paula Garcia-Esparcia, Matthias Schmitz, Duru Ozbay, Susana Correia, Ângela Correia, Ira Milosevic, Olivier Andréoletti, Natalia Fernández-Borges, Ina M Vorberg, Markus Glatzel, Theodoros Sklaviadis, Juan Maria Torres, Susanne Krasemann, Raquel Sánchez-Valle, Isidro Ferrer, Inga Zerr
• Journal: Molecular neurodegeneration (Mol Neurodegener) Vol. 12 Issue 1 Pg. 83 (Nov 10 2017) ISSN: 1750-1326 [Electronic] England
• PMID: 29126445 (Publication Type: Journal Article)

Chemical References

• Biomarkers
• CHI3L1 protein, human
• Chitinase-3-Like Protein 1

Topics

• Aged
• Animals
• Biomarkers (analysis)
• Brain (metabolism)
• Cerebrospinal Fluid (metabolism)
• Chitinase-3-Like Protein 1 (analysis, biosynthesis)
• Dementia (metabolism)
• Female
• Humans
• Male
• Mice
• Mice, Transgenic
• Middle Aged
• Neurodegenerative Diseases (metabolism)