p38 Stress Kinase Controls Late Apoptotic Events in L‐Glutamine‐deprived Sp2/0‐Ag14 Murine Hybridoma Cells
Bibliographic record
Abstract
L‐Glutamine (Gln) starvation triggers apoptosis in Sp2/0‐Ag14 (Sp2/0) murine hybridoma cells within 1 hour. Here we report on the role of p38, a stress‐signalling kinase, in this phenomenon. p38 activation occurred after key events necessary for commitment to apoptosis, such as caspase‐3 activation and mitochondrial dysfunction. Furthermore, inhibition of p38 with SB203580 prior to Gln starvation did not prevent caspase activation. On the other hand, SB203580 treatment reduced both nuclear condensation and apoptotic body formation, implicating p38 in modulating late apoptotic events. Gln withdrawal‐induced caspase activation and cell death were inhibited by Bcl‐xL overexpression or by pre‐incubation with Z‐VAD‐fmk. Interestingly, p38 activity was inhibited in Bcl‐xL expressing cells, but not by Z‐VAD‐fmk treatment, indicating that p38 activation is downstream of the mitochondria but independent of caspase activation. Moreover, N‐acetyl‐cysteine prevented p38 phosphorylation, indicating that p38 activation is triggered by an oxidative stress. Altogether, our findings indicate that p38 does not contribute to the induction of cell death in Gln starved Sp2/0 cells. Rather, Gln withdrawal leads to mitochondrial dysfunction, resulting in an oxidative stress and p38 activation. Activated p38 would then promote late apoptotic events. Research supported by NSERC‐Canada.
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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) | 0.001 | 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 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".