TRAIL (TNF-related apoptosis-inducing ligand, encoded by the TNFSF10 gene) is a type II transmembrane protein belonging to the TNF superfamily. It functions as a homotrimeric cytokine capable of inducing apoptosis through engagement of death receptors DR4 (TRAIL-R1) and DR5 (TRAIL-R2). TRAIL plays a dual role in the nervous system: it contributes to immune surveillance and tumor cell killing, but can also mediate pathological neuronal death in Alzheimer's disease, Parkinson's disease, and other neurodegenerative conditions. [1]
| Property | Value |
|---|---|
| Gene Symbol | TNFSF10 |
| Chromosomal Location | 3q26 |
| UniProt ID | P50591 |
| Molecular Weight | 32.5 kDa (monomer), ~97.5 kDa (homotrimer) |
| Protein Length | 281 amino acids |
| Structure | Type II transmembrane protein with extracellular TNF homology domain |
| Cellular Location | Cell surface (membrane-bound) and soluble (cleaved form) |
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TRAIL signals through a complex system of receptors:
| Receptor | Gene | Signaling Capability |
|---|---|---|
| DR4 (TRAIL-R1) | TNFRSF10A | Death domain, triggers apoptosis |
| DR5 (TRAIL-R2) | TNFRSF10B | Death domain, triggers apoptosis |
| Receptor | Gene | Function |
|---|---|---|
| DcR1 (TRAIL-R3) | TNFRSF10C | GPI-anchored, no intracellular domain |
| DcR2 (TRAIL-R4) | TNFRSF10D | Truncated death domain, non-functional |
| Osteoprotegerin (OPG) | TNFRSF11B | Soluble decoy receptor |
When TRAIL binds DR4 or DR5:
In the healthy CNS, TRAIL has several important physiological roles:
TRAIL is strongly implicated in Alzheimer's disease pathogenesis through multiple mechanisms. [1:1]
TRAIL is expressed in brain cells of Alzheimer's disease patients at significantly elevated levels compared to age-matched controls. Both neurons and glial cells can express TRAIL, and its expression colocalizes with amyloid plaques and in vulnerable brain regions including the hippocampus and entorhinal cortex. [@uberto2004]
Aβ oligomers induce TRAIL expression in neurons, astrocytes, and microglia through:
Once induced, TRAIL acts in an autocrine and paracrine manner to promote neuronal apoptosis. Aβ-induced neuronal death can be significantly attenuated by neutralizing TRAIL with soluble decoy receptors or blocking antibodies. [2]
TRAIL contributes to neuronal death through:
In Parkinson's disease, TRAIL contributes to dopaminergic neuron death:
TRAIL mediates neuronal death in alcohol use disorder through neuroinflammation. [3]
| Strategy | Mechanism | Status |
|---|---|---|
| TRAIL-neutralizing antibodies | Block TRAIL interaction with death receptors | Preclinical |
| DR5-Fc decoy receptors | Soluble receptor fusion protein scavenges TRAIL | Preclinical |
| siRNA against TRAIL | Reduce TRAIL expression | Preclinical |
| FADD dominant-negative | Block DISC formation | Preclinical |
No TRAIL-targeted therapies have reached clinical trials for neurodegenerative disease. TRAIL-based anticancer therapies (recombinant TRAIL, agonistic antibodies) have been tested in oncology but faced limitations due to liver toxicity and insufficient efficacy as monotherapy.
| Partner | Interaction Type | Function |
|---|---|---|
| DR4 (TNFRSF10A) | Receptor binding | Initiates apoptosis signaling |
| DR5 (TNFRSF10B) | Receptor binding | Primary signaling receptor in neurons |
| FADD | Adaptor protein | DISC formation |
| Caspase-8 | Proteolysis | Initiator caspase activation |
| Bid | Proteolysis | Cross-link to mitochondrial pathway |
| DcR1 (TNFRSF10C) | Decoy binding | Non-signaling decoy |
| DcR2 (TNFRSF10D) | Decoy binding | Non-signaling decoy |
| Aβ oligomers | Synergistic toxicity | Upregulates TRAIL expression |
Burgaletto C, et al. The immune system on the TRAIL of Alzheimer's disease. Advances in Experimental Medicine and Biology. 2020. ↩︎ ↩︎
Cantarella G, et al. Neutralization of TRAIL death pathway protects human neuronal cell line from beta-amyloid toxicity. Molecular Biology of the Cell. 2003. ↩︎
Qin L, et al. TRAIL Mediates Neuronal Death in AUD: A Link between Neuroinflammation and Neurodegeneration. Biomolecules. 2021. ↩︎