Casp1 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.
The CASP1 Gene encodes caspase-1, a cysteine-aspartic protease that plays a central role in the innate immune response by catalyzing the activation of inflammatory cytokines through the inflammasome. Caspase-1 is a key executor of pyroptosis, a form of programmed cell death that releases pro-inflammatory intracellular contents.
| CASP1 - Caspase 1 |
|---|
| Full Name | Caspase 1 |
| Chromosome | 11q22.3 |
| NCBI Gene ID | 842 |
| OMIM ID | 147678 |
| Ensembl ID | ENSG00000145629 |
| UniProt ID | P29465 |
| Associated Diseases | Alzheimer's Disease, Parkinson's Disease, ALS, Multiple Sclerosis, Stroke, Rheumatoid Arthritis |
Caspase-1 is synthesized as a zymogen (pro-caspase-1, ~45 kDa) consisting of:
- N-terminal CARD domain (~90 amino acids): Caspase recruitment domain for adaptor protein binding
- Linker region: Contains the autocleavage sites
- Large subunit (p20, ~20 kDa): Contains the catalytic cysteine residue
- Small subunit (p10, ~10 kDa): Completes the active site
The active enzyme is a heterotetramer consisting of two p20/p10 heterodimers that form a functional caspase-1 holoenzyme[1].
Caspase-1 is the central protease of the inflammasome complex:
Caspase-1 is activated by various pattern recognition receptors (PRRs):
- NLRP1, NLRP3, NLRC4: Cytosolic sensors for bacterial/viral components
- AIM2: DNA sensor for viral and microbial DNA
- Pyrin: Rho GTPase sensor for bacterial toxins
Upon activation, these sensors recruit the adaptor protein ASC (PYCARD) via PYD-PYD interactions, which then recruits pro-caspase-1 through CARD-CARD interactions, forming the canonical inflammasome complex.
Active caspase-1 cleaves pro-inflammatory cytokines:
- Pro-IL-1β (31 kDa) → mature IL-1β (17 kDa)[2]
- Pro-IL-18 (24 kDa) → mature IL-18 (18 kDa)[3]
- Pro-IL-33 (31 kDa) → mature IL-33 (25 kDa)[4]
These cytokines are secreted and propagate the inflammatory response.
Caspase-1 also cleaves:
- Gasdermin D: The executioner of pyroptotic cell death, creating membrane pores[5]
- MLKL: Connects necroptosis and pyroptosis pathways
- Caspase-1 activation in microglia contributes to chronic neuroinflammation[6]
- IL-1β promotes amyloid-beta plaque formation and tau phosphorylation
- NLRP3 inflammasome is activated by amyloid-beta aggregates[7]
- Caspase-1 cleaves tau, generating neurotoxic fragments
- Genetic variants in CASP1 associated with increased AD risk
- IL-18 contributes to synaptic dysfunction and memory impairment
- Caspase-1 mediates dopaminergic neuron death[8]
- Activated by alpha-synuclein aggregates via NLRP3
- IL-1β and IL-18 contribute to chronic neuroinflammation
- Inhibition of caspase-1 is neuroprotective in PD models
- Gasdermin D-mediated pyroptosis in microglia
- Caspase-1 activation in motor neurons and glia[9]
- Contributes to inflammation-driven disease progression
- TDP-43 aggregates activate the NLRP3 inflammasome
- SOD1 mutations trigger inflammasome activation
- Demyelination involves caspase-1-dependent inflammatory pathways[10]
- IL-1β promotes Th17 differentiation
- NLRP3 inflammasome activation in microglia
- Caspase-1 inhibition reduces disease severity in EAE
¶ Stroke and Brain Injury
- Ischemic injury triggers rapid NLRP3 inflammasome activation
- Caspase-1 mediates neuronal cell death after stroke
- IL-1β amplifies excitotoxic damage
Caspase-1 is expressed in various brain cell types:
| Cell Type |
Expression Level |
Notes |
| Neurons |
Moderate |
Increases in response to injury |
| Microglia |
High |
Constitutive in survey microglia |
| Astrocytes |
Low-Moderate |
Inducible upon activation |
| Oligodendrocytes |
Low |
Increases in demyelinating conditions |
Expression is induced by:
- Pro-inflammatory cytokines (TNF-α, IFN-γ)
- Pathogen-associated molecular patterns (LPS, flagellin)
- Damage-associated molecular patterns (ATP, ROS, uric acid crystals)
- Mitochondrial dysfunction and cellular stress
- VX-765/Belnacasan: Oral pro-drug, Phase II trials for psoriasis
- Pralnacasan (VX-740): Withdrawn from Phase II for liver toxicity
- Emricasan: Pan-caspase inhibitor, tested in liver disease
- NLRP3-specific inhibitors: Target upstream activation
- IL-1 receptor antagonists: Block downstream signaling (Anakinra, Canakinumab)
- Gasdermin D inhibitors: Block pyroptotic cell death
- ASC specks inhibitors: Block inflammasome assembly
- Canakinumab (anti-IL-1β) being explored in AD and PD
- NLRP3 inhibitors in early clinical development for neurodegenerative diseases
- Thornberry NA, et al. (1992). "A novel heterodimeric cysteine protease is required for interleukin-1β processing in monocytes". Nature. PMID:1537207[1]
- Martinon F, Burns K, Tschopp J. (2002). "The inflammasome: a molecular platform triggering activation of inflammatory caspases and processing of proIL-1β". Mol Cell. PMID:11897747[2]
- Gu Y, et al. (1997). "Activation of interferon-γ inducing factor by interleukin-1β and interleukin-18 in human peripheral blood mononuclear cells". J Exp Med. PMID:9271585[3]
- Luthi AU, et al. (2009). "Suppression of interleukin-33 bioactivity through proteolysis by active caspases". Immunity. PMID:19119088[4]
- Kayagaki N, et al. (2015). "Caspase-11 cleaves gasdermin D for non-canonical inflammasome signalling". Nature. PMID:26475259[5]
- Heneka MT, et al. (2013). "NLRP3 is activated in Alzheimer's disease and contributes to amyloid-β pathology". Nature. PMID:23307503[6]
- Zhang Y, et al. (2015). "NLRP3 inflammasome and Parkinson's disease". Mol Neurobiol. PMID:25981466[7]
- Wang W, et al. (2021). "Caspase-1-mediated pyroptosis in dopaminergic neurons". Cell Death Dis. PMID:33619259[8]</sup]
- de Rivero Vaccari JP, et al. (2016). "Therapeutic targeting of the inflammasome in ALS". J Neurochem. PMID:27113566[9]
- Mc Guire C, et al. (2013). "Caspase-1 deficiency in mice reduces experimental autoimmune encephalomyelitis". J Neuroimmunol. PMID:24055156[10]
- PAMPs/DAMPs activate PRRs (NLRP3, AIM2, etc.)
- PRRs recruit ASC adaptor protein
- ASC recruits pro-caspase-1 via CARD domain
- Pro-caspase-1 undergoes autocleavage
- Active caspase-1 releases mature cytokines
- Gasdermin D cleavage triggers pyroptosis
- Inflammatory cell death releases DAMPs
- Amplification of inflammatory response
- NF-κB pathway: Positive feedback for inflammasome activation
- MAPK pathways: Synergistic inflammatory signaling
- Type I interferon response: AIM2 inflammasome activation
- Apoptosis pathway: Caspase-1 independent cell death
The study of Casp1 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.
- Thornberry NA, et al. (1992). A novel heterodimeric cysteine protease is required for interleukin-1β processing in monocytes. Nature. 356:768-774. PMID:1537207
- Martinon F, Burns K, Tschopp J. (2002). The inflammasome: a molecular platform triggering activation of inflammatory caspases and processing of proIL-1β. Mol Cell. 10:417-426. PMID:11897747
- Gu Y, et al. (1997). Activation of interferon-γ inducing factor by interleukin-1β and interleukin-18 in human peripheral blood mononuclear cells. J Exp Med. 186:1757-1762. PMID:9271585
- Luthi AU, et al. (2009). Suppression of interleukin-33 bioactivity through proteolysis by active caspases. Immunity. 31:84-98. PMID:19119088
- Kayagaki N, et al. (2015). Caspase-11 cleaves gasdermin D for non-canonical inflammasome signalling. Nature. 526:666-671. PMID:26475259
- Heneka MT, et al. (2013). NLRP3 is activated in Alzheimer's disease and contributes to amyloid-β pathology. Nature. 493:674-678. PMID:23307503
- Zhang Y, et al. (2015). NLRP3 inflammasome and Parkinson's disease. Mol Neurobiol. 52:1304-1311. PMID:25981466
- Wang W, et al. (2021). Caspase-1-mediated pyroptosis in dopaminergic neurons. Cell Death Discov. 7:18. PMID:33619259
- de Rivero Vaccari JP, et al. (2016). Therapeutic targeting of the inflammasome in ALS. J Neurochem. 139:271-283. PMID:27113566
- Mc Guire C, et al. (2013). Caspase-1 deficiency in mice reduces experimental autoimmune encephalomyelitis. J Neuroimmunol. 263:83-89. PMID:24055156
- Li S, et al. (2019). Caspase-1 gasdermin D pathway in the pathogenesis of ALS. Front Cell Neurosci. 13:404. PMID:31474839
- Song L, et al. (2017). NLRP3 inflammasome in neurological diseases. Mol Neurobiol. 54:2837-2849. PMID:27083576