Component
Intracellular NAD restoration from extracellular precursors in human cells
Context-specific entity; species, compartment and exposure are stated on each claim.
1 recorded relationships. Experimental role, claim status and evidence remain attached to each record.
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.
Other things that act on it
Enzymes, hormones, genes, and other components with a recorded effect. These are not nutrients, so they do not count toward the arrows above. Each finding names the chapter that recorded it.
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.
What acts on it
CD73 knockout did not prevent human cancer cells from using extracellular NAD+ or NMN to restore intracellular NAD+ under the tested conditions.
Experimental context and source evidence
- evidence_access
- Primary full text
- experimental_model
- Human cancer-cell CRISPR knockout and precursor supplementation.
- limitations
- Does not identify a universal alternative uptake route or prove intact NAD crossed the plasma membrane.
- nutrient_topic
- NAD+ collection; molecular form, preparation, species, exposure and manipulation remain explicit. · NAD+
- plain_language
- Cells could still use outside precursor material without CD73.
- primary_references
- Extracellular NAD+ enhances PARP-dependent DNA repair capacity independently of CD73 activity. · 2020 · https://pubmed.ncbi.nlm.nih.gov/31959836/ · DOI 10.1038/s41598-020-57506-9
NAD+: compartmental supply, consumption and cross-nutrient mechanisms (2026-09-19) · lines 244–250
AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Human cancer-cell CRISPR knockout and precursor supplementation. · source_derived_draft · unverified_draft
## nad-plus-cd73-knockout Cells could still use outside precursor material without CD73. CD73 knockout did not prevent human cancer cells from using extracellular NAD+ or NMN to restore intracellular NAD+ under the tested conditions. Model: Human cancer-cell CRISPR knockout and precursor supplementation. Limitations: Does not identify a universal alternative uptake route or prove intact NAD crossed the plasma membrane. Evidence access: Primary full text Extracellular NAD+ enhances PARP-dependent DNA repair capacity independently of CD73 activity. · 2020 · https://pubmed.ncbi.nlm.nih.gov/31959836/ · DOI 10.1038/s41598-020-57506-9
Complete structured claim and evidence
The events it takes part in
A mechanism often involves more than two components. These are the full events, with every participant and its role.
Situations it appears in
Low-supply and faulty-machinery situations recorded in the chapters where this component plays a part.
In the sources
Preserved passages that mention this component, quoted exactly. Open one to read it in context.
Open hypotheses
Proposed ideas that involve this component. They are labeled as hypotheses and do not change any recorded statement.
This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.