CHI3L1 Gene

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CHI3L1 Gene

Introduction

<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">CHI3L1 Gene</th>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>CHI3L1</td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>Chitinase 3-Like 1</td>
</tr>
<tr>
<td class="label">Chromosomal Location</td>
<td>1q32.1</td>
</tr>
<tr>
<td class="label">NCBI Gene ID</td>
<td>1116</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>P36222</td>
</tr>
<tr>
<td class="label">Ensembl ID</td>
<td>ENSG00000133048</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">ALS</a>, <a href="/wiki/aging" style="color:#ef9a9a">Aging</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/alzheimer" style="color:#ef9a9a">Alzheimer</a>, <a href="/wiki/amyotrophic-lateral-sclerosis" style="color:#ef9a9a">Amyotrophic Lateral Sclerosis</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">178 edges</a></td>
</tr>
</table>

Chi3L1 Gene is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

Pathway Diagram

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CHI3L1 Gene

Introduction

Chi3L1 Gene is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

Pathway Diagram

Mermaid diagram (expand to render)

Knowledge graph relationships for CHI3L1 (321 total edges in KG)

Overview

CHI3L1 (Chitinase 3-Like 1) is a secreted glycoprotein that serves as a biomarker for neuroinflammation in neurodegenerative diseases. Also known as YKL-40, it is produced by activated [microglia](/cell-types/microglia-neuroinflammation), [astrocytes](/entities/astrocytes), and macrophages in response to inflammatory stimuli. [@cell]

Gene Information

Normal Function

CHI3L1 is a member of the glycosyl hydrolase family 18 but lacks enzymatic activity. It functions as:

Extracellular matrix remodeling - binds to chitin, heparin, and collagen
Cell proliferation and differentiation - modulates growth factor signaling
Inflammatory response regulator - enhances cytokine production by immune cells
Microglial activation marker - indicates neuroinflammatory states

Disease Associations

Alzheimer's Disease

Elevated CSF and plasma YKL-40 levels correlate with disease progression
Associated with [tau](/proteins/tau) pathology and cognitive decline
May predict conversion from MCI to AD
Studied as a complementary biomarker to amyloid and [tau](/proteins/tau)

Parkinson's Disease

Increased YKL-40 in CSF of PD patients
Correlates with disease severity and motor symptoms
Associated with neuroinflammatory processes in substantia nigra

Multiple Sclerosis

Strong marker for microglial activation
Associated with lesion load and disease progression
Different from classical inflammatory markers

Amyotrophic Lateral Sclerosis

Elevated in CSF and serum
Correlates with disease progression rate
May reflect non-neuronal (glial) involvement

Expression Pattern

Brain: Highly expressed in [hippocampus](/brain-regions/hippocampus), [cortex](/brain-regions/cortex), and basal ganglia
Cell Types: Primarily microglia and astrocytes
Induction: Pro-inflammatory cytokines (IL-1β, TNF-α, IFN-γ)

Therapeutic Implications

YKL-40 as a therapeutic target:

Anti-inflammatory strategies may reduce YKL-40-mediated inflammation
Monoclonal antibodies against YKL-40 in development
Biomarker utility for patient stratification and treatment monitoring

Key Publications

[YKL-40 in Alzheimer's disease](https://pubmed.gov/23467410) - Mathews et al., Neurology, 2013

[YKL-40 as neuroinflammation marker in Parkinson's disease](https://pubmed.gov/28761934) - Wu et al., J Neuroinflammation, 2017

[CSF YKL-40 in ALS patients](https://pubmed.gov/26961712) - Sjögren et al., Neurology, 2016

[YKL-40 in multiple sclerosis](https://pubmed.gov/22689767) - Cantó et al., Mult Scler, 2012

[YKL-40 and tau pathology](https://pubmed.gov/29348219) - Querol-Vilaseca et al., JAD, 2017

Cross-Links

[Alzheimer's Disease Biomarkers](/diseases/alzheimers-disease-biomarkers)
[Parkinson's Disease Biomarkers](/biomarkers/parkinsons-disease-biomarkers)
[Neuroinflammation Pathway](/mechanisms/neuroinflammation-pathway)
[Microglia](/cell-types/microglia)
[CSF Biomarkers](/biomarkers/csf-biomarkers)

Background

The study of Chi3L1 Gene has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.

Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.

External Links

[NCBI Gene: CHI3L1](https://www.ncbi.nlm.nih.gov/gene/1116)
[UniProt: P36222](https://www.uniprot.org/uniprot/P36222)
[GeneCards: CHI3L1](https://www.genecards.org/cgi-bin/carddisp.pl?gene=CHI3L1)

Expression Pattern

CHI3L1/YKL-40 shows cell-type and region-specific expression:

[Brain cells*: Primarily activated microglia and astrocytes](/cell-types/microglia)
Peripheral immune cells: Macrophages, neutrophils
[Brain regions*: Highest in hippocampus, basal ganglia, and white matter](/brain-regions)
[Disease states*: Expression increases dramatically in neuroinflammatory conditions](/genes/nfl)

CSF and plasma YKL-40 levels provide information about ongoing neuroinflammatory processes in the central nervous system.

Molecular Mechanisms

Despite lacking enzymatic activity, CHI3L1 exerts multiple functions:

[@ecm]: ECM Remodeling: Binds to chitin, heparin, and various collagen types
[@cell]: Cell Signaling: Interacts with IL-13Rα2 to activate MAPK and PI3K/Akt pathways
[@cella]: Cell Migration: Promotes migration of macrophages and astrocytes
[@angiogenesis]: Angiogenesis: Induces endothelial cell proliferation and tube formation
[@inflammation]: Inflammation: Modulates cytokine production and immune cell activation

Cellular sources in the CNS:

Microglia: Primary source in neurodegenerative diseases
Astrocytes: Particularly in reactive astrocytes surrounding plaques
Neurons: Limited expression, increases in stressed neurons

Therapeutic Implications

CHI3L1 as a biomarker and therapeutic target:

Biomarker utility: YKL-40 levels correlate with disease progression
Anti-YKL-40 antibodies: Being developed to neutralize YKL-40
Small molecule inhibitors: Targeting IL-13Rα2 signaling
Microglial modulation: Reducing CHI3L1-expressing microglia

Clinical applications:

Prognostic biomarker in AD and PD
Treatment response monitoring
Disease progression tracking

Animal Models

Chi3l1 knockout mice: Show altered inflammatory responses
Transgenic overexpression: Develop enhanced neuroinflammation
Mouse models of AD: YKL-40 correlates with plaque load
PD models: Increased YKL-40 in substantia nigra

Research Directions

Developing YKL-40-targeted therapeutics
Understanding CHI3L1's protective vs. pathogenic roles
Biomarker validation in large clinical cohorts
Multi-analyte biomarker panels including YKL-40

References

Pathway Diagram

The following diagram shows the key molecular relationships involving CHI3L1 Gene discovered through SciDEX knowledge graph analysis:

Mermaid diagram (expand to render)

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CHI3L1 Gene

CHI3L1 Gene

Introduction

Pathway Diagram

CHI3L1 Gene

Introduction

Pathway Diagram

Overview

Gene Information

Normal Function

Disease Associations

Alzheimer's Disease

Parkinson's Disease

Multiple Sclerosis

Amyotrophic Lateral Sclerosis

Expression Pattern

Therapeutic Implications

Key Publications

Cross-Links

Background

See Also

External Links

Expression Pattern

Molecular Mechanisms

Therapeutic Implications

Animal Models

Research Directions

References

Pathway Diagram