Characterization of astrocytes derived from human NTera‐2/D1 embryonal carcinoma cells
Bibliographic record
Abstract
Astrocytes are the predominant cell type in the vicinity of glutamatergic synapses, where they monitor and maintain low levels of glutamate. Synaptic homeostasis of glutamate involves its removal from the synaptic cleft via high-affinity glutamate transporters, glutamate transporter-1 (GLT-1)/excitatory amino acid transporters (EAAT)2 and glutamate and aspartate transporter (GLAST)/EAAT1, and glutamate-catabolizing enzyme, glutamine synthase. Glutamate transporters have been mostly characterized in rodent astrocytes, due to the lack of a convenient human cell system. We report here that NTera-2 (NT2/D1, a cell line derived from a human teratocarcinoma and known to differentiate into neurons) can also be differentiated by a 4-week treatment with retinoic acid into functional astrocytes (NT2/A). Differentiation was accompanied by decreased cell proliferation and cell-cycle arrest, as measured by flow cytometry, immunostaining for Ki67 and incorporation of 5-bromo-2'deoxyuridine (BrdU). Immunocytochemistry and Western blot analysis showed that NT2/A expressed glial fibrillary acidic protein, vimentin and S100beta. Reverse transcription polymerase chain reaction (PCR) detected mRNA encoding glutamate transporters GLT-1/EAAT2 and GLAST/EAAT1. The expression level of GLAST/EAAT1 was higher than that of GLT-1/EAAT2, which is a typical expression pattern for primary astrocytes. Functionality of the transporters was demonstrated by the uptake of (3)H-glutamate. NT2/A also expressed active glutamine synthase, and treatment with glutamate (up to 1 mM for 24 hr) was non-toxic, suggesting that these cells were capable of converting it to non-toxic metabolites. NT2/A and NT2-derived neurons could be grown as mixed cultures and this may prove to be a useful experimental model to study molecular mechanisms underlying glutamate excitotoxicity.
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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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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".