Interleukin 1 Receptor Type 1 Protein is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
The Interleukin-1 Receptor Type 1 (IL-1R1) is a critical membrane receptor that mediates pro-inflammatory signaling in the brain and peripheral tissues. It is the primary signaling receptor for interleukin-1 (IL-1) cytokines, including IL-1α and IL-1β, and plays a central role in neuroinflammation, a hallmark of neurodegenerative diseases including Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS).
| Interleukin-1 Receptor Type 1 Protein |
|---|
| Gene | IL1R1 |
| UniProt ID | P01589 |
| PDB IDs | 1G0R, 1IRA, 2NVW |
| Molecular Weight | ~80 kDa (glycosylated) |
| Subcellular Localization | Cell membrane (type I transmembrane) |
| Protein Family | IL-1 receptor family (TIR domain superfamily) |
| Expression | Ubiquitous (neurons, astrocytes, microglia, endothelial cells) |
IL-1R1 is essential for the brain's innate immune response and mediates both physiological processes (fever, sleep regulation, memory formation) and pathological chronic inflammation in neurodegenerative conditions.
IL-1R1 is a type I transmembrane receptor with distinct structural domains:
¶ Extracellular Domain (1-319 amino acids)
- Three immunoglobulin-like (Ig-like) domains
- Ligand-binding site for IL-1α, IL-1β, and IL-1Ra
- Disulfide bonds (Cys residues) for structural stability
- Contains the IL-1 receptor accessory protein (IL-1R3) binding interface
¶ Transmembrane Domain (320-340 amino acids)
- Single α-helical transmembrane segment
- Anchors receptor in the plasma membrane
- Connects extracellular sensing to intracellular signaling
¶ Cytoplasmic Domain (341-569 amino acids)
- Toll/IL-1 Receptor (TIR) domain (~180 amino acids)
- Critical for downstream signal transduction
- Contains conserved BB loop motif essential for MyD88 recruitment
- IL-1R3 (IL-1RAcP - IL-1 Receptor Accessory Protein) is required for signal transduction
- Forms heterodimeric complex with IL-1R1 upon ligand binding
- Co-receptor binding induces conformational change enabling signaling
IL-1R1 mediates the potent pro-inflammatory effects of IL-1 cytokines in the central nervous system:
¶ Ligand Binding and Specificity
- IL-1β: Highest affinity (Kd ~ 10⁻¹¹ M), primary pro-inflammatory ligand
- IL-1α: Lower affinity, acts locally in tissues
- IL-1 Receptor Antagonist (IL-1Ra): Binds without signaling, endogenous antagonist
- IL-1β binds to extracellular domain of IL-1R1
- IL-1R3 (co-receptor) recruited to form signaling complex
- TIR domains aggregate, recruiting MyD88 adaptor protein
- MyD88 recruits IRAK4 (IL-1 Receptor-Associated Kinase 4)
- IRAK4 phosphorylates IRAK1/2
- TRAF6 (TNF Receptor-Associated Factor 6) activated
- Downstream activation of:
- NF-κB (Nuclear Factor kappa-B) - primary pathway
- MAPK (Mitogen-Activated Protein Kinases) - JNK, p38, ERK
- AP-1 transcription factor
- Fever generation: Acts on hypothalamic thermoregulatory centers
- Sleep regulation: Promotes slow-wave sleep
- Memory and synaptic plasticity: IL-1 modulates hippocampal synaptic transmission
- Acute phase response: Hepatic production of inflammatory proteins
- Leukocyte recruitment: Up-regulation of adhesion molecules
- Cytokine storm: Amplification of inflammatory signaling
- Normal synaptic plasticity and memory formation (at low levels)
- Response to infection and tissue injury
- Regulation of neurogenesis
- Modulation of neurotransmitter systems
IL-1R1 overexpression is a hallmark of neuroinflammation in AD:
- Elevated expression: IL-1R1 is significantly upregulated in AD brain (hippocampus, cortex)
- Amyloid interaction: IL-1β promotes amyloid-beta (Aβ) production via BACE1 upregulation
- Tau pathology: Enhances tau phosphorylation and aggregation
- Synaptic dysfunction: IL-1 signaling disrupts synaptic plasticity
- Glial activation: Perpetuates microglial and astrocyte activation
- Therapeutic implication: IL-1R1 antagonist anakinra shows promise in preclinical studies
Key References:
- Rubinow KB, et al. (2016). IL-1β in AD pathogenesis. J Neuroinflammation
- Shaftel SS, et al. (2008). Chronic IL-1β expression in AD. Proc Natl Acad Sci
IL-1R1 mediates dopaminergic neuron loss:
- Increased expression: Elevated in substantia nigra pars compacta of PD patients
- Dopaminergic vulnerability: IL-1β accelerates α-synuclein aggregation
- BBB permeability: Increases blood-brain barrier leakiness
- Microglial activation: Creates pro-inflammatory micro-environment
- Therapeutic potential: IL-1R1 blockade protects dopaminergic neurons in models
Key References:
- Cao JJ, et al. (2012). IL-1β in PD. Neurosci Lett
-文献: Brotchie JM (2003). IL-1 and PD progression. Mov Disord
IL-1R1 contributes to motor neuron injury:
- Microglial activation: Perpetuates inflammatory microenvironment
- Motor neuron toxicity: Direct effects on vulnerable motor neurons
- Disease progression: Correlates with disease severity
- Therapeutic targeting: IL-1R1 antagonists under investigation
Key References:
- Hoozemans JJ, et al. (2012). IL-1β in ALS. Acta Neuropathol
- Beers DR, et al. (2008). Microglial IL-1β in ALS. J Neurochem
¶ Stroke and Traumatic Brain Injury (TBI)
IL-1R1 mediates secondary brain injury:
- Ischemic damage: Exacerbates neuronal death post-stroke
- Excitotoxicity: Amplifies glutamate-induced toxicity
- BBB disruption: Increases vascular permeability
- Therapeutic window: IL-1R1 blockade beneficial in preclinical models
IL-1R1 drives demyelination:
- Autoimmune pathogenesis: Central to experimental autoimmune encephalomyelitis (EAE)
- Demyelination: Promotes oligodendrocyte death
- Clinical trials: IL-1R1 antagonists being explored
IL-1R1 is a validated drug target for inflammatory diseases:
| Drug |
Type |
Mechanism |
Indications |
| Anakinra |
Recombinant IL-1Ra |
Blocks IL-1R1 |
RA, CAPS, Still's disease |
| Canakinumab |
Anti-IL-1β monoclonal antibody |
Neutralizes IL-1β |
CAPS, TRAPS, gout |
| Rilonacept |
IL-1R1-Fc fusion |
Decoy receptor |
CAPS |
- Anakinra: Phase 2 trial for AD (NCT03269114)
- Canakinumab: Investigated for AD and cardiovascular disease
- Novel small molecules: Brain-penetrant IL-1R1 inhibitors in development
- Blood-brain barrier penetration
- Pleiotropic functions of IL-1
- Safety concerns with immunosuppression
- mTOR pathway: IL-1β activates mTORC1
- JAK/STAT: IL-1 induces STAT3 phosphorylation
- NLRP3 inflammasome: IL-1R1 priming and activation
- IL1R1 polymorphisms associated with:
- Increased AD risk (rs3917262)
- Altered cytokine responses
- Variable treatment response
- Soluble IL-1R1 (sIL-1R1): Detectable in cerebrospinal fluid
- Phospho-NF-κB: Downstream marker of IL-1R1 activation
- IL-1β/IL-1Ra ratio: Reflects inflammatory status
The study of Interleukin 1 Receptor Type 1 Protein 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.
- Sims JE, et al. (1988). IL-1 receptor cDNA cloning. Nature. PMID:2845076
- Dinarello CA (2018). IL-1β in inflammation. Int J Mol Sci. PMID:30428608
- Liu X, Chan CB (2014). IL-1R1 signaling in AD. J Alzheimers Dis. PMID:24577446
- Shaftel SS, et al. (2008). Chronic IL-1β expression. Proc Natl Acad Sci USA. PMID:18332429
- Griffin WS, et al. (2006). IL-1 in AD. Neurobiol Aging. PMID:16480789
- Pinteaux E, et al. (2002). IL-1 in brain injury. Prog Neurobiol. PMID:11950646
- Basu A, et al. (2012). IL-1R1 in PD. Neurosci Lett. PMID:22609826
- Drouin-Ouellet J, et al. (2015). IL-1R1 and neuroinflammation. J Neuroinflammation. PMID:25889899