Component
ApoER2 / LRP8
Receptor involved in SELENOP uptake in brain and testis.
4 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 it acts on
ApoER2/LRP8-mediated SELENOP uptake contributes to preferential brain and testis selenium retention during dietary restriction in experimental models.
Experimental context and source evidence
- availability_state
- Dietary selenium availability declines.
- experimental_scope
- Tissue-selective distribution, largely from experimental models; relative retention differs from absolute protection.
- limitations
- There is no fixed human organ sacrifice sequence. Low circulating SELENOP can also reflect inflammation, and receptor disruption is a distinct machinery state.
- trigger_kind
- nutrient_deficiency
Selenium deficiency: a mechanism-first reference · lines 129–139
Supplied selenium deficiency reference · supports · Supplied reference; verify the primary study and experimental context. · source_derived_draft · unverified_draft
2.2 Tissue hierarchy Selenium distribution is also tissue-selective. Brain and testis can retain selenium relatively well during dietary restriction, in part through SELENOP receptor biology. ApoER2/LRP8 is important for SELENOP uptake in the brain and testis; megalin/LRP2 contributes to renal handling of filtered selenium-containing proteins. A safer conceptual map is: LESS RETENTION / EARLIER FALL STRONGER RETENTION IN MANY MODELS plasma, liver, skeletal muscle ───────────────► brain, testis tissue- and model-dependent The liver is a major producer of circulating SELENOP. Severe deficiency can produce cardiac and skeletal-muscle pathology, while the brain may be relatively protected in some experimental models. That does not establish one fixed organ-by-organ sacrifice order in humans.
Complete structured claim and evidenceApoER2 intracellular-domain mutant experiments separate selenium uptake from its Dab1-associated signaling requirement.
Experimental context and source evidence
- cell_type
- Brain and testis tissue
- experimental_model
- ApoER2 domain-mutant mice; brain/testis selenium assays
- limitations
- Does not rule out every possible cross-talk or competition mechanism.
- organism
- Mus musculus
Selenium: literature corrections and mechanism additions · lines 1468–1478
Metabolic Ledger literature curation, 17 September 2026; primary papers linked individually · supports · ApoER2 domain-mutant mice; brain/testis selenium assays · secondary_verified · secondary_verified
## lrp8-dab1-separation Sharing a receptor does not mean uptake requires the same signaling adaptor. ApoER2 intracellular-domain mutant experiments separate selenium uptake from its Dab1-associated signaling requirement. Organism: Mus musculus Cell type: Brain and testis tissue Experimental model: ApoER2 domain-mutant mice; brain/testis selenium assays Limitations: Does not rule out every possible cross-talk or competition mechanism. Primary reference: [Differential Functions of the Apoer2 Intracellular Domain in Selenium Uptake and Cell Signaling](https://pmc.ncbi.nlm.nih.gov/articles/PMC2642607/)
Complete structured claim and evidenceLRP8 loss caused GPX4 UGA-associated ribosome stalling in the tested cancer cells.
Experimental context and source evidence
- cell_type
- cancer cell lines
- experimental_model
- Genetic disruption and ribosome analyses
- limitations
- Tumor-cell result; GPX4 priority is context dependent.
- organism
- human
Selenium: literature corrections and mechanism additions · lines 594–604
Metabolic Ledger literature curation, 17 September 2026; primary papers linked individually · supports · Genetic disruption and ribosome analyses · secondary_verified · secondary_verified
## lrp8-loss-promotes-gpx4-stalling Disrupted selenium uptake hindered GPX4 production in these cancer cells. LRP8 loss caused GPX4 UGA-associated ribosome stalling in the tested cancer cells. Organism: human Cell type: cancer cell lines Experimental model: Genetic disruption and ribosome analyses Limitations: Tumor-cell result; GPX4 priority is context dependent. Primary reference: [Ribosome stalling during selenoprotein translation exposes a ferroptosis vulnerability](https://pubmed.ncbi.nlm.nih.gov/35637349/)
Complete structured claim and evidence
Where it participates (unsigned role)
An ApoER2 variant containing its O-linked glycosylation domain bound SELENOP with high affinity in the tested system.
Experimental context and source evidence
- cell_type
- Jurkat
- experimental_model
- Receptor-variant assays
- limitations
- Do not generalize to all LRP8 variants.
- organism
- human
Selenium: literature corrections and mechanism additions · lines 546–556
Metabolic Ledger literature curation, 17 September 2026; primary papers linked individually · supports · Receptor-variant assays · secondary_verified · secondary_verified
## lrp8-variant-binds-selenop A receptor variant improved SELENOP binding. An ApoER2 variant containing its O-linked glycosylation domain bound SELENOP with high affinity in the tested system. Organism: human Cell type: Jurkat Experimental model: Receptor-variant assays Limitations: Do not generalize to all LRP8 variants. Primary reference: [An efficient selenium transport pathway of selenoprotein P utilizing a high-affinity ApoER2 receptor variant and being independent of selenocysteine lyase](https://pubmed.ncbi.nlm.nih.gov/37406814/)
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.