Gonadotropin-Releasing Hormone-I or -II Interacts with IGF-I/Akt But Not Connexin 43 in Human Granulosa Cell Apoptosis
Bibliographic record
Abstract
BACKGROUND: We have recently demonstrated that GnRH-I or -II can induce apoptosis in immortalized human granulosa cells by activating the caspase signaling cascade. Whether GnRH-I or -II can affect other regulators such as Bcl-2 family members, IGF-I, or gap junctions and the mechanisms involved are unknown. METHODS: Immortalized human granulosa cells were treated with GnRH-I, GnRH-II, IGF-I, or antide (a GnRH-I receptor antagonist), in various combinations. Cell proliferation and apoptotic changes were evaluated by cell counting, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and immunoblotting. Activated or total protein expression of IGF-I receptor, Akt, connexin 43 (Cx43), or caspase-3 with and without dominant-negative Akt (an Akt-suppressing vector), wortmannin (a phosphatidylinositol-3-kinase inhibitor), or Cx43 small interfering RNA transfection were assessed by immunoblotting. Gap junctional communication was determined by dye transfer assay. RESULTS: GnRH-I or -II inhibited cell proliferation, induced TUNEL-positive cells, and increased caspase-3 activities but had no effects on Bcl-2 family members. IGF-I increased cell proliferation, decreased TUNEL-positive cells and caspase-3 activities, and increased Akt activities, and these effects were attenuated by GnRH-I or -II. Effects of IGF-I on caspase-3 activities were attenuated by dominant-negative Akt or wortmannin. GnRH-I or -II decreased dye transfer, increased Cx43 phosphorylation, and increased caspases-3 activities even after Cx43 knockdown. CONCLUSION: GnRH-I or -II induces apoptosis in human granulosa cells through a caspase-3-dependent extrinsic pathway rather than a Bcl-2 family-dependent intrinsic pathway and attenuates the antiapoptotic action of IGF-I through Akt. Cx43-induced gap junctional changes do not initiate granulosa cell apoptosis but likely result from apoptosis induced by GnRH-I or -II.
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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 | 0.000 |
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".