TNF-alpha Protein - Tumor Necrosis Factor

TNF-alpha Protein - Tumor Necrosis Factor

Introduction

Tnf Alpha Protein Tumor Necrosis Factor is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

<div class="infobox infox-protein"> [@qin2022]
<div class="infobox-header">TNFA Protein</div> [@liu2022]
<div class="infobox-row"> [@shi2017]
<div class="infobox-label">Gene</div> [@qin2007]
<div class="infobox-value">[TNF](/genes/tnf)</div> [@kabba2017]
</div> [@zhang2023]
<div class="infobox-row"> [@chen2024]
<div class="infobox-label">Full Name</div> [@mccoy2006]
<div class="infobox-value">Tumor Necrosis Factor Alpha (TNF-α)</div> [@swardfager2010]
</div>
<div class="infobox-row">
<div class="infobox-label">UniProt ID</div>
<div class="infobox-value">[P01375](https://www.uniprot.org/uniprot/P01375)</div>
</div>
<div class="infobox-row">
<div class="infobox-label">PDB Structure IDs</div>
<div class="infobox-value">1TNF, 1A8M, 1T4G</div>
</div>
<div class="infobox-row">
<div class="infobox-label">Molecular Weight</div>
<div class="infobox-value">25,600 Da (monomer), 51,200 Da (homotrimer)</div>
</div>
<div class="infobox-row">
<div class="infobox-label">Subcellular Localization</div>
<div class="infobox-value">Secreted, plasma membrane</div>
</div>
<div class="infobox-row">
<div class="infobox-label">Protein Family</div>
<div class="infobox-value">TNF superfamily</div>
</div>
</div>

Overview

TNF-alpha Protein - Tumor Necrosis Factor

Introduction

Tnf Alpha Protein Tumor Necrosis Factor is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.

<div class="infobox infox-protein"> [@qin2022]
<div class="infobox-header">TNFA Protein</div> [@liu2022]
<div class="infobox-row"> [@shi2017]
<div class="infobox-label">Gene</div> [@qin2007]
<div class="infobox-value">[TNF](/genes/tnf)</div> [@kabba2017]
</div> [@zhang2023]
<div class="infobox-row"> [@chen2024]
<div class="infobox-label">Full Name</div> [@mccoy2006]
<div class="infobox-value">Tumor Necrosis Factor Alpha (TNF-α)</div> [@swardfager2010]
</div>
<div class="infobox-row">
<div class="infobox-label">UniProt ID</div>
<div class="infobox-value">[P01375](https://www.uniprot.org/uniprot/P01375)</div>
</div>
<div class="infobox-row">
<div class="infobox-label">PDB Structure IDs</div>
<div class="infobox-value">1TNF, 1A8M, 1T4G</div>
</div>
<div class="infobox-row">
<div class="infobox-label">Molecular Weight</div>
<div class="infobox-value">25,600 Da (monomer), 51,200 Da (homotrimer)</div>
</div>
<div class="infobox-row">
<div class="infobox-label">Subcellular Localization</div>
<div class="infobox-value">Secreted, plasma membrane</div>
</div>
<div class="infobox-row">
<div class="infobox-label">Protein Family</div>
<div class="infobox-value">TNF superfamily</div>
</div>
</div>

Overview

The TNFA protein is encoded by the [TNF](/proteins/tnf-protein) gene and is implicated in neurodegenerative disease pathogenesis.

Structure

TNF-α is synthesized as a 26 kDa transmembrane precursor (pro-TNF) that is cleaved by TACE (TNF-α converting enzyme, also known as ADAM17) to release the mature 17 kDa soluble cytokine. The active form is a stable homotrimer that engages two distinct receptors: TNFR1 (p55, TNFRSF1A) and TNFR2 (p75, TNFRSF1B).

Normal Function

TNF-α is a master regulator of inflammation and cell survival. TNFR1 is expressed ubiquitously and contains a death domain that can trigger [apoptosis](/entities/apoptosis) or necroptosis. TNFR2 is expressed primarily on immune cells and endothelial cells, promoting cell survival and proliferation through [NF-κB](/entities/nf-kb) signaling. In the CNS, TNF is produced by [microglia](/entities/microglia), [astrocytes](/entities/astrocytes), and [neurons](/entities/neurons), where it regulates synaptic plasticity, sleep, and feeding behavior.

Role in Disease

TNF is a central mediator of neuroinflammation in AD, PD, MS, and ALS. In AD, TNF promotes [amyloid-beta](/proteins/amyloid-beta) production, enhances excitotoxicity, and contributes to synaptic dysfunction. In PD, TNF from activated [microglia](/cell-types/microglia-neuroinflammation) induces dopaminergic neuron death. Elevated CSF TNF levels correlate with disease severity in MS and ALS. TNF polymorphisms affect disease risk and progression.

Therapeutic Targeting

TNF inhibitors are widely used in autoimmune diseases (RA, IBD, psoriasis). For neurodegenerative diseases, strategies include: (1) anti-TNF antibodies (etanercept, infliximab, adalimumab); (2) TNF receptor-Fc fusion proteins; (3) small molecule TACE inhibitors to block TNF release; (4) blood-brain barrier penetrating anti-TNF compounds. Some clinical trials have shown benefit in AD and PD.

Animal Models

Mouse models with TNF knockout or transgenic expression have been developed to study disease mechanisms.

Research Directions

Current research focuses on:

• Understanding the precise molecular mechanisms in neurodegeneration
• Developing biomarkers for disease progression
• Clinical trials targeting TNFA pathways

Key Publications

See Also

• [TNF Gene](/proteins/tnf-protein)
• [Neuroinflammation](/mechanisms/neuroinflammation)
• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Parkinson's Disease](/diseases/parkinsons-disease)
• [Multiple Sclerosis](/diseases/multiple-sclerosis)

External Links

• [UniProt: TNFA](https://www.uniprot.org/uniprot/P01375)
• [PDB: TNFA](https://www.rcsb.org/)
• [NCBI Gene: TNF](https://www.ncbi.nlm.nih.gov/gene/)

Signaling Pathways

• NF-κB pathway: Canonical pro-inflammatory signaling cascade
• MAPK pathways: JNK, p38, and ERK activation
• Caspase-8 mediated apoptosis: Extrinsic cell death pathway
• [Necroptosis](/entities/necroptosis): Programmed necrotic cell death pathway
• JAK/STAT signaling: Cytokine-mediated gene transcription

Receptor Biology

• TNFR1 (TNFRSF1A): Ubiquitously expressed, mediates most pro-inflammatory effects
• TNFR2 (TNFRSF1B): Restricted expression, primarily anti-inflammatory
• Soluble receptors: Act as decoys, modulate TNF bioavailability

Therapeutic Targeting

• Biologics: Infliximab, adalimumab, etanercept (TNF inhibitors)
• Small molecules: Triptolide, curdran
• Signal transduction inhibitors: NF-κB pathway blockers
• [Blood-brain barrier](/entities/blood-brain-barrier) penetration: Challenge for CNS applications

Biomarkers

• Serum TNF levels: Elevated in AD, PD, ALS
• CSF TNF: Correlates with disease progression
• Soluble TNFR1/2: Biomarkers of neuroinflammation

Background

The study of Tnf Alpha Protein Tumor Necrosis Factor 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.

References