Janus kinase 3 (JAK3) increases phosphorylation of signal transducers and activators of transcription 3 (STAT3) in reproductive cells
Bibliographic record
Abstract
JAK3 is a member of the membrane‐associated non‐receptor tyrosine kinase protein family and is considered predominantly expressed in hematopoietic cells. We previously identified JAK3 as a differentially expressed gene in granulosa cells (GC) of bovine preovulatory follicles. This study aimed to further investigate JAK3 mRNA and protein regulation and to identify its binding partners in GC of bovine dominant follicles. GC were obtained from small follicles (SF), dominant follicles at day 5 of the estrous cycle (DF), and ovulatory follicles, 24 hours following hCG injection (OF). RT‐PCR analyses showed greatest expression of JAK3 in GC of DF, while the weakest expression was in OF (P < 0.0001). There was a 5‐ and 20‐fold reduction of JAK3 steady‐state mRNA levels in follicular walls, respectively at 12 and 24 hours post‐hCG as compared to 0 hour (P < 0.05). These results were confirmed in western blot analysis showing weakest JAK3 protein levels in OF as compared to DF. Yeast two‐hybrid screening of a DF‐cDNA library resulted in the identification of 23 JAK3 partners in GC. Moreover, the amount of phosphorylated STAT3 in GC was greatest in SF and DF as compared to OF while the opposite was observed for non‐phosphorylated STAT3. In functional studies using bovine endometrial cells, we discovered that phosphorylation of STAT3 (pSTAT3) in a bovine endometrial cell line was increased by JAK3 while inhibition of JAK3 by JANEX‐1 decreased the amount of pSTAT3. In the same study, we showed that JAK3 increased endometrial cell proliferation as well. We found a similar effect of JAK3 on STAT3 phosphorylation using an immortalized murine granulosa cell line. These results support a physiologically relevant role of JAK3 in follicular development and provide insights into the mode of action and function of JAK3 in reproductive tissues. Support or Funding Information This work was supported in part by internal funds from Université de Montréal to KN and by a Discovery Grant from Natural Sciences and Engineering Research Council of Canada (NSERC) to JGL.
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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) | 0.002 | 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".