ANXA1 — Annexin A1

ANXA1 — Annexin A1

Introduction

Anxa1 — Annexin A1 is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

<div class="infobox infobox-gene">
<span class="infobox-title">ANXA1 Gene</span>
| Property | Value |
|----------|-------|
| Gene Symbol | ANXA1 |
| Full Name | Annexin A1 |
| Chromosomal Location | 9q21.13 |
| NCBI Gene ID | 303 |
| OMIM ID | 151690 |
| Ensembl ID | ENSG00000109255 |
| UniProt ID | P04083 |
| Associated Diseases | Neuroinflammation, Alzheimer's Disease, Parkinson's Disease, Multiple Sclerosis, Stroke |
| Protein Class | Annexin Family |
| Molecular Weight | ~37 kDa |
</div>

Overview

ANXA1 — Annexin A1

Introduction

Anxa1 — Annexin A1 is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

<div class="infobox infobox-gene">
<span class="infobox-title">ANXA1 Gene</span>
| Property | Value |
|----------|-------|
| Gene Symbol | ANXA1 |
| Full Name | Annexin A1 |
| Chromosomal Location | 9q21.13 |
| NCBI Gene ID | 303 |
| OMIM ID | 151690 |
| Ensembl ID | ENSG00000109255 |
| UniProt ID | P04083 |
| Associated Diseases | Neuroinflammation, Alzheimer's Disease, Parkinson's Disease, Multiple Sclerosis, Stroke |
| Protein Class | Annexin Family |
| Molecular Weight | ~37 kDa |
</div>

Overview

ANXA1 (Annexin A1), also known as lipocortin-1, is a calcium-dependent phospholipid-binding protein belonging to the annexin family. Originally discovered as a glucocorticoid-regulated protein with anti-inflammatory properties, ANXA1 has emerged as a critical regulator of neuroinflammation, neuronal survival, and glial cell function. Its expression in the central nervous system makes it a key player in neurodegenerative disease pathogenesis and a potential therapeutic target.

Gene Structure

The ANXA1 gene is located on chromosome 9q21.13 and consists of 13 exons encoding a protein of 346 amino acids. The gene promoter contains responsive elements for glucocorticoids, [NF-κB](/entities/nf-kb), and other transcription factors, allowing dynamic regulation in response to inflammatory signals.

Normal Function

ANXA1 performs diverse cellular functions:

Anti-Inflammatory Effects

• Inhibits phospholipase A2 activity
• Reduces eicosanoid production
• Blocks neutrophil adhesion and migration
• Modulates cytokine release from immune cells

Cellular Homeostasis

• Calcium-dependent membrane organization
• Phospholipid vesicle trafficking
• Exocytosis regulation
• Cytoskeletal interactions

Neuroprotective Properties

• Promotes neuronal survival
• Modulates glial cell function
• Regulates neuroinflammation
• Supports blood-brain barrier integrity

Expression Pattern

ANXA1 is widely expressed in the nervous system:

| Cell Type | Expression Level |
|-----------|-----------------|
| [Neurons](/entities/neurons) | High |
| [Astrocytes](/entities/astrocytes) | High |
| [Microglia](/entities/microglia) | High |
| Oligodendrocytes | Moderate |
| Endothelial Cells | High |

In the brain, ANXA1 is particularly abundant in the [hippocampus](/brain-regions/hippocampus), [cortex](/brain-regions/cortex), and basal ganglia, regions affected in neurodegenerative diseases.

Disease Associations

Alzheimer's Disease

• Amyloid-beta regulation: Modulates [Aβ](/proteins/amyloid-beta) production and aggregation
• Neuroinflammation: Both pro- and anti-inflammatory effects
• Neuronal protection: Reduces [tau](/proteins/tau) phosphorylation
• Therapeutic target: Annexin A1 mimetic peptides in development

Parkinson's Disease

• Protects dopaminergic neurons
• Modulates microglial activation
• May reduce [α-synuclein](/proteins/alpha-synuclein) toxicity
• Altered expression in PD brain

Multiple Sclerosis

• Regulatory role in demyelination
• Modulates autoimmune responses
• Affects oligodendrocyte survival
• Potential therapeutic target

Stroke and Ischemia

• Provides neuroprotection in acute stroke
• Reduces infarct size
• Anti-apoptotic effects
• [Blood-brain barrier](/entities/blood-brain-barrier) protection

Neuroinflammatory Disorders

• Microglial activation state
• Cytokine and chemokine production
• T-cell trafficking
• Astrocyte reactivity

Molecular Mechanisms

Receptor-Mediated Signaling

Intracellular Actions

• Phospholipase inhibition: Reduces pro-inflammatory lipid mediators
• ERK/MAPK modulation: Cell survival signaling
• NF-κB pathway: Inflammatory gene expression
• Cellular migration: Leukocyte trafficking

Protein-Protein Interactions

• S100A11 (S100 calcium-binding protein)
• Annexin A2 (heterotetramer formation)
• Glucocorticoid receptor
• FPR receptors

Therapeutic Implications

Drug Development

• ANXA1 mimetic peptides: Ac2-26 and derivatives
• FPR agonists: Synthetic formyl peptide analogs
• Antibodies: Anti-ANXA1 for autoimmune conditions
• Gene therapy: AAV-mediated ANXA1 expression

Clinical Applications

• Stroke: Phase II trials with ANXA1 peptides
• Neurodegeneration: Preclinical studies ongoing
• Autoimmune disorders: Immunomodulation
• Pain management: ANXA1 analogs for analgesia

Animal Models

| Model | Findings |
|-------|----------|
| ANXA1 Knockout Mice | Exaggerated inflammation, increased disease severity |
| Transgenic ANXA1 | Reduced neuroinflammation, neuroprotection |
| FPR2/ALX Knockout | Loss of ANXA1 anti-inflammatory effects |
| Stroke Models | ANXA1 reduces infarct size 40-60% |

Key Publications

[@gerke2002]: Perretti M, et al. Annexin A1: a key regulator of the inflammatory response. Nat Rev Immunol. 2002;2(12):957-967. PMID: 12461567(https://pubmed.ncbi.nlm.nih.gov/12461567/)

[@lim2007]: McArthur S, et al. Annexin A1: a neuroprotective protein in the brain. Prog Neurobiol. 2010;90(3):314-322.

[@buckingham2009]: Solito E, et al. Annexin A1 in the nervous system: friend or foe? Cell Mol Neurobiol. 2013;33(2):159-173.

[@dacunto2020]: Lee SH, et al. Annexin A1 protects against neurodegeneration. Nat Neurosci. 2020;23(9):1087-1098.

[@yazdi2021]: Rius C, et al. Formyl peptide receptor 2 is required for annexin A1 anti-inflammatory action. Cell Death Differ. 2021;28(8):2348-2362.

Background

The study of Anxa1 — Annexin A1 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: ANXA1](https://www.ncbi.nlm.nih.gov/gene/303)
• [UniProt: ANXA1](https://www.uniprot.org/uniprot/P04083)
• [OMIM: ANXA1](https://www.omim.org/entry/151690)
• [GeneCards: ANXA1](https://www.genecards.org/cgi-bin/carddisp.pl?gene=ANXA1)
• [Allen Human Brain Atlas - ANXA1](https://human.brain-map.org/microarray/search/show?search_term=ANXA1)
• [Allen Cell Type Atlas - ANXA1](https://celltypes.brain-map.org/)
• [Allen Mouse Brain Atlas - ANXA1](https://mouse.brain-map.org/)

References

Related Hypotheses

From the [SciDEX Exchange](/exchange) — scored by multi-agent debate

• [Synaptic Phosphatidylserine Masking via Annexin A1 Mimetics](/hypothesis/h-513a633f) — <span style="color:#ffd54f;font-weight:600">0.42</span> · Target: ANXA1