Affinage

NTF3

Neurotrophin-3 · UniProt P20783

Length
257 aa
Mass
29.4 kDa
Annotated
2026-06-10
18 papers in source corpus 10 papers cited in narrative 10 extracted findings
Cross-family judge vs UniProt: Affinage preferred faithfulness: 6/6 claims corpus-supported (100%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

NTF3 (neurotrophin-3/NGF-2) is a secreted cysteine-knot neurotrophic factor that signals through the Trk family of receptor tyrosine kinases to control neuronal survival, fate, and synaptic integrity (PMID:1367285, PMID:39832740). It promotes survival of dorsal root ganglion and nodose ganglion sensory neurons, defining a neurotrophic activity distinct from NGF (PMID:1367285), and its functional output depends on Trk receptor engagement, as neutralizing anti-NTF3 antibodies that block receptor binding abolish its activity (PMID:39832740). In the developing neocortex NTF3 acts downstream of Sip1 (Zeb2) as a retrograde feedback signal from postmitotic neurons to progenitors, driving the switch from apical to basal progenitors and from deep-layer to upper-layer neuronal fate; gain of NTF3 expands basal progenitors while its loss increases layer VI neurons (PMID:25085976). Downstream signaling proceeds through PI3K/AKT, where AAV knockdown and pharmacological PI3K inhibition place NTF3 upstream of this axis in neuroprotection (PMID:39690816), and transcriptome analysis links it additionally to MAPK signaling (PMID:39828780). NTF3 transcription is directly driven by POU3F2 binding to its promoter during neuronal differentiation (PMID:29549646) and is induced by NF-κB during cell-suspension stress (PMID:23185507), while its message is post-transcriptionally repressed by miR-200c and miR-21 (PMID:23185507, PMID:39828780). In the cochlea NTF3 levels must be tightly balanced: gene transfer to deafened cochleae promotes regrowth of peripheral auditory fibers (PMID:25726967), whereas overexpression in normal cochleae disrupts inner-hair-cell synapses and shifts hearing thresholds (PMID:27525291).

Mechanistic history

Synthesis pass · year-by-year structured walk · 9 steps
  1. 1991 Medium

    Established that NTF3 is a bona fide neurotrophic factor with target specificity distinct from NGF, defining its core biological activity.

    Evidence In vitro survival assay of DRG and nodose ganglion neurons using conditioned medium from COS cells expressing human NGF-2 cDNA

    PMID:1367285

    Open questions at the time
    • Receptor responsible for survival not identified
    • No downstream signaling pathway dissected
    • Single lab, single method
  2. 2008 Low

    Connected NTF3/TrkC signaling to enteric nervous system development by identifying a candidate missense variant in Hirschsprung disease patients.

    Evidence Mutational screening of NTF3 (G76R) in HSCR patients vs controls with SNP association

    PMID:18639687

    Open questions at the time
    • No functional validation of the G76R variant in vitro or in vivo
    • Causality not established
    • Small patient sample
  3. 2012 Medium

    Revealed an NF-κB-driven transcriptional and miRNA-controlled circuit governing NTF3 expression, and showed NTF3 can activate TrkB to confer anoikis resistance in cancer.

    Evidence Luciferase reporter (miR-200c/NTF3 3'UTR), NF-κB inhibition, suspension-induced expression, anoikis assays in TNBC cells

    PMID:23185507

    Open questions at the time
    • TrkB activation shown functionally but direct binding not structurally resolved
    • Generality beyond TNBC unknown
  4. 2014 High

    Placed NTF3 as a retrograde feedback signal from neurons to progenitors controlling cortical fate-switching, positioning it within a developmental signaling hierarchy below Sip1.

    Evidence Genetic epistasis in mouse neocortex with conditional Ntf3 overexpression, knockout, and comparison to Sip1 mutants

    PMID:25085976

    Open questions at the time
    • Receptor on progenitors mediating the feedback not defined
    • Downstream effector pathway in progenitors unresolved
  5. 2015 Medium

    Demonstrated therapeutic potential of NTF3 gene transfer for auditory fiber regrowth while showing neurotrophin-specific differences in spiral ganglion preservation.

    Evidence In vivo AAV.Ntf3 vs AAV.BDNF delivery in deafened guinea pig cochlea with morphological assessment

    PMID:25726967

    Open questions at the time
    • Molecular basis of differential Ntf3 vs BDNF effects unresolved
    • Functional hearing recovery not assessed
  6. 2016 Medium

    Showed NTF3 dosage must be tightly regulated, as overexpression in healthy cochlea is itself pathogenic for synapses, refining the therapeutic window concept.

    Evidence Adeno/AAV Ntf3 inoculation into normal guinea pig cochlea with ABR and histology of synaptic ribbons

    PMID:27525291

    Open questions at the time
    • Mechanism by which excess NT-3 disrupts synapses unknown
    • Receptor signaling threshold not quantified
  7. 2018 High

    Identified POU3F2 as a direct transcriptional activator of NTF3 during neuronal differentiation, defining an upstream regulator of its expression.

    Evidence ChIP-seq, promoter mutagenesis luciferase reporter, siRNA knockdown, and recombinant NTF3 rescue in mouse neurons

    PMID:29549646

    Open questions at the time
    • Other promoter-binding regulators not mapped
    • In vivo relevance of POU3F2-NTF3 axis untested in animals
  8. 2024 Medium

    Placed NTF3 upstream of PI3K/AKT in neuroprotection, linking its activity to a defined intracellular survival pathway in CNS injury.

    Evidence Mouse ICH model with AAV NTF3 knockdown and PI3K inhibitor LY294002, with Western blot and transcriptomics

    PMID:39690816

    Open questions at the time
    • Receptor coupling NTF3 to PI3K/AKT in striatum not identified
    • Direct vs indirect pathway engagement unresolved
  9. 2025 Medium

    Provided structural confirmation that NTF3 is a cysteine-knot protein engaging Trk receptors and that receptor engagement is the functional mechanism, validated by neutralizing antibodies; separately linked NTF3 to PI3K-AKT and MAPK in cancer.

    Evidence X-ray crystallography of Fab/NTF3 complex with phage-display antibody isolation and functional inhibition; miR-21/NTF3 luciferase reporter with proliferation/migration/apoptosis assays and transcriptome KEGG/GO analysis

    PMID:39828780 PMID:39832740

    Open questions at the time
    • Crystal structure of NTF3 bound to a Trk receptor not reported
    • Receptor specificity (TrkC vs TrkB) in these contexts not resolved

Open questions

Synthesis pass · forward-looking unresolved questions
  • Which Trk receptor NTF3 engages in each tissue context and how receptor choice dictates the divergent outcomes (progenitor feedback, cochlear synapse maintenance, cancer survival vs suppression) remains unresolved.
  • No structure of an NTF3-Trk complex
  • Receptor identity in cortical feedback and cochlear contexts not defined
  • Context-dependent pro- vs anti-tumor roles mechanistically unexplained

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0048018 receptor ligand activity 2 GO:0060089 molecular transducer activity 2
Localization
GO:0005576 extracellular region 1
Pathway
R-HSA-162582 Signal Transduction 2 R-HSA-1266738 Developmental Biology 1
Partners
NTRK2NTRK3

Evidence

Reading pass · 10 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
1991 NTF3 (NGF-2) promotes survival of dorsal root ganglion (DRG) and nodose ganglion sensory neurons in vitro, demonstrating neurotrophic activity distinct from NGF; conditioned medium from COS cells expressing human NGF-2 cDNA was sufficient to support neuronal survival. In vitro neuronal survival assay using conditioned medium from COS cells transfected with human NGF-2 cDNA expression plasmid Research communications - Institute for Fermentation, Osaka Medium 1367285
2012 NTF3 activates TrkB to induce anoikis resistance in triple-negative breast cancer (TNBC) cells; NF-κB (via RelA and NF-κB1 subunits) transcriptionally up-regulates both TrkB and NTF3 upon cell suspension, and NTF3 is a direct post-transcriptional target of miR-200c. Luciferase reporter assay (miR-200c targeting NTF3 3'UTR), NF-κB inhibition experiments, suspension-induced expression analysis, functional anoikis assays PloS one Medium 23185507
2014 In developing mouse neocortex, Ntf3 acts downstream of Sip1 (Zeb2) as a feedback signal from postmitotic neurons to progenitors, promoting the switch from apical progenitors (AP) to basal progenitors (BP) and from deep-layer to upper-layer neuronal fate; Ntf3 overexpression in neurons increases BP production at the expense of APs, while Ntf3 loss increases layer VI neurons. Genetic epistasis in mouse neocortex: conditional Ntf3 overexpression in neurons, Ntf3 loss-of-function (knockout), comparison with Sip1 mutant phenotype Development (Cambridge, England) High 25085976
2015 AAV-delivered Ntf3 gene transfer to the deafened guinea pig cochlea promotes regrowth of peripheral auditory fibers (PAFs) in the basilar membrane area; however, BDNF was more effective than NT-3 in preserving spiral ganglion neurons (SGNs), indicating differential neurotrophin effects in the auditory system. In vivo AAV vector delivery (AAV.Ntf3 vs AAV.BDNF) in deafened guinea pig cochlea; morphological assessment of PAF regrowth and SGN counts at 3 months Scientific reports Medium 25726967
2016 Viral-mediated overexpression of Ntf3 in normal (non-deafened) guinea pig cochlea disrupts peripheral nerve endings and synaptic connections between inner hair cells and auditory nerve fibers, causing hearing threshold shifts, indicating that the level of NT-3 must be tightly regulated for normal cochlear synapse maintenance. Adenovirus and AAV Ntf3 vector inoculation into perilymph/endolymph of normal guinea pig cochlea; ABR threshold measurements and histological evaluation of hair cells, nerve endings, and synaptic ribbons Molecular therapy. Methods & clinical development Medium 27525291
2018 Transcription factor POU3F2 directly binds the NTF3 promoter and positively regulates its transcription during neuronal differentiation; POU3F2 knockdown downregulates NTF3, and recombinant NTF3 rescues neuronal viability and differentiation in both NTF3- and POU3F2-knockdown cells. ChIP-seq, promoter deletion/mutation luciferase reporter assay, siRNA knockdown, rescue with recombinant NTF3 protein, co-immunostaining in developing mouse neurons Molecular neurobiology High 29549646
2008 A novel missense variant G76R in NTF3, found in two HSCR patients but absent in controls, is postulated to disrupt the NTF3/TrkC signaling pathway required for proper enteric nervous system development; the NTF3/TrkC signaling axis is implicated in neural crest cell migration, proliferation, and differentiation for ENS formation. Mutational screening of NTF3 in HSCR patients and controls; SNP association analysis Journal of pediatric surgery Low 18639687
2025 X-ray crystal structure of NTF3 in complex with an anti-NTF3 Fab revealed that NTF3 contains a flexible loop that becomes ordered upon Fab binding; NTF3 is a cysteine-knot protein that engages the Trk family of receptor tyrosine kinases. Neutralizing antibodies that inhibit NTF3 functional activity were isolated, confirming receptor engagement as the functional mechanism. X-ray crystallography of Fab/NTF3 complex; phage display antibody isolation; functional inhibition assays SLAS discovery : advancing life sciences R & D Medium 39832740
2025 miR-21 directly targets NTF3 in cervical cancer cells, as confirmed by dual luciferase reporter assay; overexpression of NTF3 inhibits cell proliferation and migration while promoting apoptosis, and NTF3 involvement in PI3K-AKT and MAPK signaling pathways was identified by transcriptome analysis. Dual luciferase reporter assay (miR-21 targeting NTF3 3'UTR), NTF3 overexpression with viability/migration/apoptosis assays, transcriptome sequencing with KEGG/GO enrichment Scientific reports Medium 39828780
2024 Esketamine (ESK) treatment activates the NTF3/PI3K/AKT signaling pathway in a mouse intracerebral hemorrhage model; AAV-mediated knockdown of NTF3 in the striatum attenuated ESK neuroprotection, and pharmacological PI3K inhibition (LY294002) similarly blocked ESK therapeutic effects, placing NTF3 upstream of PI3K/AKT in ESK-mediated neurorepair. In vivo ICH mouse model; AAV-mediated NTF3 knockdown; PI3K inhibitor (LY294002); Western blotting, immunofluorescence, RNA transcriptome sequencing CNS neuroscience & therapeutics Medium 39690816

Source papers

Stage 0 corpus · 18 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2012 miR-200c targets a NF-κB up-regulated TrkB/NTF3 autocrine signaling loop to enhance anoikis sensitivity in triple negative breast cancer. PloS one 73 23185507
2014 Ntf3 acts downstream of Sip1 in cortical postmitotic neurons to control progenitor cell fate through feedback signaling. Development (Cambridge, England) 60 25085976
2015 Differential effects of AAV.BDNF and AAV.Ntf3 in the deafened adult guinea pig ear. Scientific reports 49 25726967
2018 NTF3 Is a Novel Target Gene of the Transcription Factor POU3F2 and Is Required for Neuronal Differentiation. Molecular neurobiology 35 29549646
2017 Lnc-NTF3-5 promotes osteogenic differentiation of maxillary sinus membrane stem cells via sponging miR-93-3p. Clinical implant dentistry and related research 29 29106055
2016 Viral-mediated Ntf3 overexpression disrupts innervation and hearing in nondeafened guinea pig cochleae. Molecular therapy. Methods & clinical development 25 27525291
2008 NTF-3, a gene involved in the enteric nervous system development, as a candidate gene for Hirschsprung disease. Journal of pediatric surgery 24 18639687
2004 The role of beta-catenin, TGF beta 3, NGF2, FGF2, IGFR2, and BMP4 in the pathogenesis of mesenteric sclerosis and angiopathy in midgut carcinoids. Human pathology 17 15188132
2017 5-Aza-2'-deoxycytidine in the medial prefrontal cortex regulates alcohol-related behavior and Ntf3-TrkC expression in rats. PloS one 14 28614398
2025 miR-21 promotes cervical cancer by regulating NTF3. Scientific reports 10 39828780
2024 Esketamine Provides Neuroprotection After Intracerebral Hemorrhage in Mice via the NTF3/PI3K/AKT Pathway. CNS neuroscience & therapeutics 7 39690816
2015 Polymorphisms of the neurotrophic factor-3 (NTF-3) in Alzheimer's disease: rs6332 associated with onset time and rs6489630 T allele exhibited a protective role. Journal of neurogenetics 7 26814132
2019 Regulation of Lnc-NTF3-5 on islet β-cell dysfunction in high glucose environment and related mechanisms. European review for medical and pharmacological sciences 6 31841205
2025 EDN1 and NTF3 in keloid pathogenesis: computational and experimental evidence as novel diagnostic biomarkers for fibrosis and inflammation. Frontiers in genetics 5 40051702
2025 Discovery metabolomics and genetic analysis reveal lipid pathway alterations associated with malignant phenotype acquisition in pleomorphic adenoma and a novel NTF3::ITPR2 fusion in carcinoma ex pleomorphic adenoma. Virchows Archiv : an international journal of pathology 1 41081890
2021 miRNAs regulating the expressions of NTF3, GNG2 and ITGA7 are involved in the pathogenesis of abdominal aortic aneurysm in mice. General physiology and biophysics 1 33655887
2025 Identification of unique binding mode anti-NTF3 antibodies from a novel long VH CDR3 phage display library. SLAS discovery : advancing life sciences R & D 0 39832740
1991 Effect of NGF-2 on the survival of chick sensory ganglion neurons in vitro. Research communications - Institute for Fermentation, Osaka 0 1367285

Missed literature

Know a paper Affinage missed for NTF3? Flag it for the maintainers and the community.

No submissions yet.