Protein tyrosine kinase and protein phosphatase signaling pathways regulate volume-sensitive chloride currents in a nonpigmented ciliary epithelial cell line.
Bibliographic record
Abstract
PURPOSE: To investigate whether signaling pathways that incorporate protein tyrosine kinases and phosphatases regulate PKC-sensitive, volume-sensitive Cl(-) currents (I(Cl,vol)) in cultured rabbit nonpigmented ciliary epithelial cells. METHODS: Activation of I(Cl,vol) in response to hyposmotic stimulation was recorded with whole-cell patch-clamp techniques in the presence of pharmacologic agents that activate or block kinases and phosphatases. RESULTS: I(Cl,vol) in rabbit nonpigmented ciliary epithelial cells was identified as a PKC-sensitive, volume-sensitive Cl(-) current, because current was downregulated during cell swelling by phorbol-12-dibutyrate, a PKC activator, and the PKC inhibitors, calphostin and chelerythrine, enhanced the current. Activation of c-Src tyrosine kinases, with an Src activator peptide (EPQ(pY)EEIPI), increased I(Cl,vol) after hyposmotic stimulation, whereas the protein tyrosine kinase inhibitor, genistein, but not its inactive analogue daidzein, inhibited the current. The phosphatidylinositol-3-kinase (PI3K) inhibitor, wortmannin, inhibited I(Cl,vol). Wortmannin did not further inhibit I(Cl,vol) in cells pretreated with the protein tyrosine kinase inhibitor, genistein, but blocked enhancement of I(Cl,vol) by PKC inhibitors. The serine-threonine protein phosphatase (PP) inhibitor, okadaic acid, blocked activation of I(Cl,vol), whereas insulin, which activates PI3K and PP-1, enhanced the current. The insulin-enhanced current was also blocked by okadaic acid. I(Cl,vol) was not activated under isosmotic conditions by the simultaneous inhibition of PKC with calphostin and activation of PP-1 by insulin. CONCLUSIONS: These data show that PKC-sensitive Cl(-) currents activated in response to cell swelling in nonpigmented ciliary epithelial cells are modulated by protein tyrosine kinase, PI3K, and PP signaling pathways. Activation of PP and PKC may involve the upstream intermediaries Src tyrosine kinase and PI3K.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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) | 0.000 | 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 teacher head, 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".