Hydrolysis of Phosphatidylcholine‐Isoprostanes (PtdCho‐IP) by Peripheral Human Group IIA, V and X Secretory Phospholipases A<sub>2</sub> (sPLA<sub>2</sub>)
Bibliographic record
Abstract
Abstract Biologically active F‐ and E/D‐type‐prostane ring isomers (F2‐IP and E2/D2‐IP, respectively) are produced in situ by non‐enzymatic peroxidation of arachidonic acid esterified to GroPCho (PtdCho‐IP) and are universally distributed in tissue lipoproteins and cell membranes. Previous work has shown that platelet‐activating factor acetylhydrolases (PAF‐AH) are the main endogenous PLA2 involved in degradation of PtdCho‐IP. The present study shows that the PtdCho‐IP are also subject to hydrolysis by group IIA, V and X secretory PLA2, which also have a wide peripheral tissue distribution. For this demonstration, we compared the LC/MS profiles of PtdCho‐IP of auto‐oxidized plasma lipoproteins after incubation for 1–4 h (37 °C) in the absence or presence of recombinant human sPLA2 (1–2.5 µg/ml). In the absence of exogenously added sPLA2 the total PtdCho‐IP level after 4 h incubation reached 15.9, 21.6 and 8.7 nmol/mg protein of LDL, HDL and HDL3, respectively. In the presence of group V or group X sPLA2 (2.5 µg/ml), the PtdCho‐IP was completely hydrolyzed in 1 h, while in the presence of group IIA sPLA2 (2.5 µg/ml) the hydrolysis was less than 25% in 4 h, although it was complete after 8–24 h incubation. This report provides the first demonstration that PtdCho‐IP are readily hydrolyzed by group IIA, V and X sPLA2. A co‐location of sPLA2 and the substrates in various tissues has been recorded. Thus, the initiation of interaction and production of isoprostanes in situ are highly probable.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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".