Component

Human U2OS/H4 starvation-induced autophagic flux

Context-specific entity; species, compartment and exposure are stated on each claim.

3 recorded relationships. Experimental role, claim status and evidence remain attached to each record.

Read recorded mechanisms Open recursive mind map

How nutrients influence it

Every nutrient with a recorded effect on this component, credited to the nutrient that acted rather than the chapter that recorded it. Open a nutrient to see the findings and the conditions they were measured under.

How nutrients reach it in more than one step

Chains of two or more recorded steps that end here, grouped by the nutrient they start from. Each step is a separate finding, so a chain is a route a mechanism could take, not proof that it does.

Tracing routes…

What it does

Every recorded relationship this component is part of, grouped by its role. Plain wording comes first; the technical statement follows.

Recorded relationships

What acts on it

  1. Three ODC1-directed siRNAs depleted polyamines and reduced starvation-induced autophagic flux.

    Human ornithine decarboxylase / ODC1 → Human U2OS/H4 starvation-induced autophagic flux source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    evidence_access
    Primary full text
    experimental_model
    Human U2OS cells.
    limitations
    ODC1 supplies several polyamines; depletion is not spermidine-specific.
    nutrient_topic
    Spermidine collection; molecular form, preparation, species, exposure and manipulation remain explicit. · Spermidine
    plain_language
    Genetic evidence complements the inhibitor experiment.
    primary_references
    Spermidine is essential for fasting-mediated autophagy and longevity. · 2024 · https://pubmed.ncbi.nlm.nih.gov/39117797/ · DOI 10.1038/s41556-024-01468-x
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    Spermidine: biosynthesis, hypusination, transport and cross-nutrient mechanisms (2026-09-19) · lines 198–204

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Human U2OS cells. · source_derived_draft · unverified_draft

    ## spermidine-fasting-knockdown Genetic evidence complements the inhibitor experiment. Three ODC1-directed siRNAs depleted polyamines and reduced starvation-induced autophagic flux. Model: Human U2OS cells. Limitations: ODC1 supplies several polyamines; depletion is not spermidine-specific. Evidence access: Primary full text Spermidine is essential for fasting-mediated autophagy and longevity. · 2024 · https://pubmed.ncbi.nlm.nih.gov/39117797/ · DOI 10.1038/s41556-024-01468-x
    Complete structured claim and evidence

  2. DFMO inhibition of ODC1 reduced starvation-induced autophagic flux in U2OS and H4 cells.

    Human ornithine decarboxylase / ODC1 → Human U2OS/H4 starvation-induced autophagic flux source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    evidence_access
    Primary full text
    experimental_model
    Human tumor cell lines; 100 micromolar DFMO pretreatment and short HBSS starvation.
    limitations
    Pharmacological depletion differs from ordinary low dietary intake.
    nutrient_topic
    Spermidine collection; molecular form, preparation, species, exposure and manipulation remain explicit. · Spermidine
    plain_language
    Blocking polyamine production can interrupt the fasting response.
    primary_references
    Spermidine is essential for fasting-mediated autophagy and longevity. · 2024 · https://pubmed.ncbi.nlm.nih.gov/39117797/ · DOI 10.1038/s41556-024-01468-x
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    Spermidine: biosynthesis, hypusination, transport and cross-nutrient mechanisms (2026-09-19) · lines 182–188

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Human tumor cell lines; 100 micromolar DFMO pretreatment and short HBSS starvation. · source_derived_draft · unverified_draft

    ## spermidine-fasting-odc Blocking polyamine production can interrupt the fasting response. DFMO inhibition of ODC1 reduced starvation-induced autophagic flux in U2OS and H4 cells. Model: Human tumor cell lines; 100 micromolar DFMO pretreatment and short HBSS starvation. Limitations: Pharmacological depletion differs from ordinary low dietary intake. Evidence access: Primary full text Spermidine is essential for fasting-mediated autophagy and longevity. · 2024 · https://pubmed.ncbi.nlm.nih.gov/39117797/ · DOI 10.1038/s41556-024-01468-x
    Complete structured claim and evidence

  3. Added spermidine rescued autophagic-flux suppression caused by DFMO during starvation.

    Spermidine → Human U2OS/H4 starvation-induced autophagic flux source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    evidence_access
    Primary full text
    experimental_model
    Human U2OS/H4 cells; 10 micromolar spermidine, with 1 mM aminoguanidine in rescue conditions.
    limitations
    Serum-oxidase control matters; supplementation did not further raise flux in already-starved intact U2OS cells.
    nutrient_topic
    Spermidine collection; molecular form, preparation, species, exposure and manipulation remain explicit. · Spermidine
    plain_language
    Replacing the missing metabolite restored a response.
    primary_references
    Spermidine is essential for fasting-mediated autophagy and longevity. · 2024 · https://pubmed.ncbi.nlm.nih.gov/39117797/ · DOI 10.1038/s41556-024-01468-x
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    Spermidine: biosynthesis, hypusination, transport and cross-nutrient mechanisms (2026-09-19) · lines 190–196

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Human U2OS/H4 cells; 10 micromolar spermidine, with 1 mM aminoguanidine in rescue conditions. · source_derived_draft · unverified_draft

    ## spermidine-fasting-rescue Replacing the missing metabolite restored a response. Added spermidine rescued autophagic-flux suppression caused by DFMO during starvation. Model: Human U2OS/H4 cells; 10 micromolar spermidine, with 1 mM aminoguanidine in rescue conditions. Limitations: Serum-oxidase control matters; supplementation did not further raise flux in already-starved intact U2OS cells. Evidence access: Primary full text Spermidine is essential for fasting-mediated autophagy and longevity. · 2024 · https://pubmed.ncbi.nlm.nih.gov/39117797/ · DOI 10.1038/s41556-024-01468-x
    Complete structured claim and evidence

In the sources

Preserved passages that mention this component, quoted exactly. Open one to read it in context.

    This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.

    Evidence, AI assistance and curation standards