Abstract 245: Intravenously Injected Human Apolipoprotein A-I Rapidly Enters the Central Nervous System via the Choroid Plexus in Mice
Bibliographic record
Abstract
Background: Lipoprotein metabolism in the brain is based on particles that resemble high-density lipoproteins (HDL) that use apolipoprotein (apo) E as opposed to apoA-I as their primary protein component. Although apoA-I is not synthesized by astrocytes or microglia, which secrete apoE, it is abundant in cerebrospinal fluid (CSF) and is readily detectable in brain tissue lysates.However, the mechanisms by which plasma apoA-I enters and is metabolized within the central nervous system (CNS) are unknown. Methods and Results: Western blot analysis shows that steady state levels of endogenous apoA-I in CSF and brain are approximately 0.01% and 10-15% of its levels in plasma and liver, respectively. Recombinant, fluorescently tagged, lipid-free human (h) apoA-I injected into the tail vein of wild-type mice localizes to the choroid plexus within 0.5h and accumulates in a saturable, dose-dependent manner in brain. hApoA-I accumulates in the brain for up to 2h, after which it is turned over with a half life of ~133 minutes, 3 times longer than the relatively quick turnover 40-45 minutes found in plasma, liver, and kidney. In vitro, hApoA-I is taken up and actively transported across confluent monolayers of primary human choroid epithelial cells. Conclusions: Following intravenous injection, hApoA-I rapidly and strongly localizes to the choroid plexus, suggesting it gains access to the CNS primarily via the blood CSF barrier. Further, apoA-I found in the CNS of mice is exclusively derived from the circulation as apoA-I mRNA is not detectable in murine brain. These results suggest that apoA-I based HDL may primarily play a role in CSF lipoprotein metabolism in addition to potentially impacting cerebrovasculature health and function from the lumen of the vessel.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.005 | 0.003 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".