Aif1 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.
Allograft Inflammatory Factor 1 (IBA1)
| Gene Symbol | AIF1 |
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| Full Name | Allograft Inflammatory Factor 1 |
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| Chromosomal Location | 6p21.3 |
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| NCBI Gene ID | 199 |
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| OMIM | 604577 |
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| Ensembl ID | ENSG00000240065 |
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| UniProt ID | P55072 |
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| Associated Diseases | Alzheimer's Disease, Parkinson's Disease, Multiple Sclerosis, Brain Ischemia |
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AIF1 Gene is involved in biological pathways relevant to neurodegenerative diseases. It plays important roles in neuronal function, cellular signaling, or stress response mechanisms.
Dysregulation or mutations in this gene/protein contribute to the pathogenesis of Alzheimer's disease, Parkinson's disease, and related neurodegenerative disorders.
AIF1 encodes Allograft Inflammatory Factor 1, also known as IBA1 (Ionized calcium-binding adapter molecule 1). This protein is a calcium-binding protein specifically expressed in microglia and activated macrophages, serving as a key marker for these cell types.
Key functions include:
- Microglial marker: IBA1 is the most widely used immunohistochemical marker for microglia in the brain
- Calcium signaling: EF-hand calcium-binding protein involved in microglial activation
- F-actin bundling: IBA1 reorganizes the actin cytoskeleton in activated microglia
- Phagocytosis: Regulates microglial phagocytic activity
- Migration: Facilitates microglial migration to sites of injury
AIF1 is induced by interferon-gamma and other pro-inflammatory stimuli. It is rapidly upregulated in activated microglia following brain injury or disease.
AIF1/IBA1 is prominently expressed in microglia surrounding amyloid plaques:
- Plaque-associated microglia: IBA1+ microglia cluster around amyloid-beta plaques in AD brain
- Disease progression: Microglial IBA1 expression correlates with disease severity
- Genetic variants: AIF1 polymorphisms have been associated with AD risk in some populations
- Therapeutic target: Modulating microglial IBA1 expression may affect neuroinflammation
Microglial activation marked by IBA1 is evident in PD brain:
- Substantia nigra: IBA1+ microglia are increased in the substantia nigra of PD patients
- Neuroinflammation: Chronic microglial activation contributes to dopaminergic neuron loss
- α-synuclein pathology: IBA1+ microglia may phagocytose and process α-synuclein aggregates
AIF1 is a key marker in MS research:
- Active lesions: IBA1+ microglia/macrophages are abundant in demyelinating lesions
- Disease activity: IBA1 expression correlates with lesion activity and progression
- Therapeutic monitoring: IBA1 immunohistochemistry is used to assess treatment response
Following stroke, IBA1+ microglia rapidly respond:
- Ischemic penumbra: Microglial activation extends beyond the core infarct
- Inflammatory cascade: IBA1+ microglia produce pro-inflammatory cytokines
- Neuronal survival: Microglial activation has both beneficial and detrimental effects
AIF1 shows highly specific expression:
- Microglia: Highest expression in brain microglia (constitutive)
- Macrophages: Expressed in activated macrophages throughout the body
- Dendritic cells: Low to moderate expression in some dendritic cell populations
- Other tissues: Generally low expression outside the immune system
In the brain, IBA1 is expressed at low levels in resting microglia and dramatically upregulated upon activation.
The study of Aif1 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.
- Ito D, et al. (1998). Microglia-specific localization of a novel calcium binding protein, Iba1. Brain Research. Molecular Brain Research. 57(1):1-9.
- Schwab JM, et al. (2000). Lesion-induced accumulation of Iba1+ macrophages: time course of invasion and distribution. Brain Research. 885(2):169-174.
- Sasaki Y, et al. (2001). Iba1 is an actin-cross-linking protein in macrophages/microglia. Biochemical and Biophysical Research Communications. 286(2):292-297.
- Walker DG, et al. (2014). Patterns of expression of IBA1 in the brains of Alzheimer's disease, Parkinson's disease and control cases. Brain Research. 1573:46-56.
Last updated: 2026-03-05