| ADAMTS13 Gene |
|---|
| Official Symbol | ADAMTS13 |
| Full Name | A Disintegrin And Metalloproteinase with Thrombospondin Motifs 13 |
| Chromosomal Location | 9q34.2 |
| NCBI Gene ID | https://www.ncbi.nlm.nih.gov/gene/11067 11067 |
| OMIM | https://www.omim.org/entry/607840 607840 |
| Ensembl ID | ENSG00000162825 |
| UniProt ID | https://www.uniprot.org/uniprot/Q76LX8 Q76LX8 |
| Associated Diseases | Thrombotic Thrombocytopenic Purpura (TTP), AD, stroke |
ADAMTS13 is a zinc-dependent metalloprotease that specifically cleaves von Willebrand factor (VWF) multimers into smaller, less pro-thrombotic units. This cleavage is essential for normal hemostasis, as it prevents the formation of unusually large VWF multimers that can cause platelet aggregation and microvascular thrombosis [1].
The protein consists of multiple domains including a propeptide, a metalloprotease domain, a disintegrin domain, multiple thrombospondin type 1 repeats (TSRs), a cysteine-rich domain, a spacer domain, and two CUB domains. The enzyme is primarily expressed in the liver, particularly by hepatic stellate cells and endothelial cells [2].
In the central nervous system, ADAMTS13 is expressed by microvascular endothelial cells and astrocytes. It plays a protective role in the blood-brain barrier (BBB) by regulating VWF-mediated platelet adhesion and preventing microthrombus formation in cerebral vasculature [3].
ADAMTS13 deficiency has been implicated in AD pathogenesis through multiple mechanisms:
- Increased VWF multimers in AD patients contribute to cerebral microvascular dysfunction
- Impaired clearance of VWF-Aβ complexes leads to accumulation of amyloid in cerebral vessels
- Microvascular inflammation and reduced cerebral blood flow [4]
- ADAMTS13 polymorphisms are associated with stroke risk
- Low ADAMTS13 activity predicts poor outcomes after ischemic stroke
- The enzyme provides neuroprotection by preventing thrombotic complications [5]
- Congenital or acquired ADAMTS13 deficiency causes TTP
- Neurological symptoms in TTP include stroke, transient ischemic attacks, and cognitive impairment
ADAMTS13 is expressed in:
- Liver: Primary site of synthesis (hepatocytes and hepatic stellate cells)
- Brain: Cerebral microvascular endothelial cells, astrocytes
- Kidney: Glomerular endothelial cells
- Plasma: Circulating enzyme at concentrations of ~1 μg/mL
In the brain, expression is highest in:
| Variant |
Effect |
Association |
| Q449E |
Reduced activity |
TTP risk |
| P618A |
Mild reduction |
Stroke risk |
| R7W |
Altered secretion |
TTP risk |
- Recombinant ADAMTS13: Being developed for congenital TTP; potential neuroprotective therapy
- ADAMTS13 agonists: Natural compounds that enhance ADAMTS13 activity may benefit AD
- Gene therapy: AAV-mediated ADAMTS13 expression under investigation
¶ Von Willebrand Factor and Amyloid-beta Interaction
The relationship between von Willebrand factor (VWF) and amyloid-beta (Aβ) represents a critical link between vascular dysfunction and neurodegeneration in AD:
- Aβ binds to VWF: Amyloid-beta peptides, particularly Aβ40 and Aβ42, can directly bind to VWF multimers
- Circulating complexes: VWF-Aβ complexes circulate in the plasma of AD patients
- Impaired clearance: These complexes are cleared less efficiently than either component alone
- Vascular deposition: Complexes may deposit in cerebral vessel walls, contributing to cerebral amyloid angiopathy (CAA)
ADAMTS13 provides neuroprotection through several mechanisms:
- VWF multimer regulation: By cleaving large VWF multimers, ADAMTS13 reduces the availability of VWF for Aβ binding
- Reduced complex formation: Less VWF means fewer VWF-Aβ complexes
- Enhanced clearance: Smaller VWF fragments are cleared more efficiently
- Reduced vascular deposition: Lower complex burden decreases CAA risk
ADAMTS13 plays a crucial role in maintaining blood-brain barrier (BBB) integrity:
- Endothelial cells: ADAMTS13 regulates VWF-mediated endothelial activation
- Tight junctions: VWF dysregulation disrupts tight junction proteins (claudin-5, occludin, ZO-1)
- Astrocyte end-feet: Perivascular astrocyte function is impaired by VWF deposits
- Pericyte coverage: Microvascular pericytes are affected by microthrombi
| Mechanism |
Effect on BBB |
| VWF cleavage |
Prevents microthrombus formation |
| Platelet regulation |
Reduces platelet-endothelial interaction |
| Inflammation reduction |
Decreases cytokine-mediated barrier disruption |
| Matrix preservation |
Maintains basement membrane integrity |
ADAMTS13 deficiency contributes to cerebral microvascular dysfunction in multiple ways:
- Large VWF multimers form microthrombi in cerebral capillaries
- These occlusions reduce cerebral blood flow (CBF)
- Chronic hypoperfusion contributes to cognitive decline
- Ischemic events accelerate neurodegeneration
- Elevated VWF indicates endothelial activation/dysfunction
- Pro-inflammatory state in cerebral vasculature
- Increased adhesion molecule expression (VCAM-1, ICAM-1)
- Enhanced leukocyte recruitment to brain parenchyma
| Marker |
Utility |
Evidence Level |
| Plasma ADAMTS13 activity |
AD diagnosis |
Moderate |
| VWF:ADAMTS13 ratio |
Disease severity |
Emerging |
| CSF ADAMTS13 |
BBB integrity |
Limited |
| Genetic variants |
Risk prediction |
Research stage |
- Early AD: Reduced ADAMTS13 activity may precede clinical symptoms
- Mild cognitive impairment: VWF:ADAMTS13 ratio correlates with conversion to AD
- Established AD: Activity levels correlate with cognitive decline rate
- Target: Congenital TTP; expanding to neuroprotection
- Delivery: Intravenous or subcutaneous administration
- Dosing: 40 IU/kg weekly in TTP; neuroprotective doses under investigation
- Blood-brain barrier penetration: Limited; may require intranasal or direct CNS delivery
Natural compounds that enhance ADAMTS13 activity:
- Curcumin: Shown to increase ADAMTS13 expression in endothelial cells
- Resveratrol: Modulates VWF and ADAMTS13 balance
- Omega-3 fatty acids: Reduce VWF while preserving ADAMTS13
- AAV vectors: Engineered to express ADAMTS13
- Target cells: Hepatocytes for systemic expression
- Challenges: Achieving therapeutic levels in CNS
- Elevated VWF:ADAMTS13 ratio
- Confirmed AD diagnosis (NIA-AA criteria)
- Stable anti-amyloid therapy if applicable
- No significant coagulopathy
- Cognitive batteries (ADAS-Cog, MoCA)
- Cerebral blood flow (ASL-MRI)
- Biomarker normalization (VWF, Aβ)
- Safety: bleeding risk, thrombotic events
| SNP |
Function |
Population Frequency |
Disease Association |
| Q449E |
Reduced activity |
~5% Caucasian |
TTP modifier |
| P618A |
Mild reduction |
~3% |
Stroke risk |
| R7W |
Altered secretion |
Rare |
TTP risk |
- Cardiovascular risk factors: Diabetes, hypertension modify ADAMTS13 function
- Smoking: Reduces ADAMTS13 activity
- Age: Natural decline in ADAMTS13 activity with age
- Inflammation: Pro-inflammatory states suppress ADAMTS13 expression
ADAMTS13 may complement anti-amyloid strategies:
- Anti-Aβ antibodies: Reduced VWF-Aβ complexes enhance antibody efficacy
- BACE1 inhibitors: Reduced Aβ production lessens VWF binding burden
- Gamma-secretase modulators: Altered Aβ profile affects VWF interactions
VWF dysfunction may accelerate tau pathology:
- Ischemia from microthrombi promotes tau phosphorylation
- Reduced cerebral blood flow affects tau clearance
- ADAMTS13 therapy may indirectly reduce tau pathology
ADAMTS13 deficiency contributes to neuroinflammation:
- Microvascular inflammation spreads to parenchyma
- Cytokine release from activated endothelium
- Enhanced microglia activation
- Astrocyte reactivity
- ** phenotype**: Elevated VWF multimers, reduced cerebral blood flow
- AD model cross: Accelerated Aβ deposition, worsened cognition
- Recovery: ADAMTS13 replacement improves outcomes
- 5xFAD mice: Reduced ADAMTS13 with disease progression
- APP/PS1 mice: VWF elevation precedes plaque deposition
- Therapeutic response: ADAMTS13 administration improves cerebral blood flow
ADAMTS13 represents a critical link between vascular function and neurodegeneration in Alzheimer's disease. Its role in cleaving von Willebrand factor multimers directly impacts cerebral microvascular health, blood-brain barrier integrity, and the formation of toxic VWF-Aβ complexes. Therapeutic strategies targeting ADAMTS13—through recombinant enzyme replacement, small molecule agonists, or gene therapy—offer promising approaches to address the vascular components of AD pathogenesis. The growing understanding of ADAMTS13's neuroprotective functions positions it as a valuable biomarker and therapeutic target for neurodegenerative disease intervention.