Development of an LC-MS/MS method for the analysis of Saccharomyces cerevisiae lipidome to determine the mechanism through which plant extract 21 delays aging by remodeling lipid composition
Bibliographic record
Abstract
Aging is a multifactorial process that occurs in all biological organisms. The biological aspects of aging are evolutionary conserved across eukaryotes. Saccharomyces cerevisiae being a unicellular eukaryote has been used as a model organism to study aging. This unicellular eukaryote has a short lifespan, a fully sequenced genome and it is easy to manipulate genetically to make changes in metabolic pathways. Hence, it has been historically used to identify genes, metabolic pathways and chemical compounds that have influence on aging process. An extract from white willow bark (which is called PE21) was discovered in Dr. Vladimir Titorenko’s lab as the plant extract capable of extending the chronological lifespan (CLS) of Saccharomyces cerevisiae. Previous studies in the lab have shown that PE21 considerably alters the lipid composition of Saccharomyces cerevisiae. Lipids play crucial roles in many important pathways related to cellular signaling network, energy storage, membrane trafficking, membrane dynamics and apoptosis. Lipidomics is a relatively new research field that aims at characterizing lipid profiles. The characterization of lipids is a difficult process because of their diverse chemical and physical properties and due to lack of sensitive tools to study them. Only with the advent of mass spectrometry it became possible to characterize individual lipid species of various lipid classes. Herein, I have developed an optimized LC-MS/MS method to successfully identify and quantify many individual species of 10 different lipid classes of Saccharomyces cerevisiae. The developed method was used to analyze the effects of PE21 on the lipid composition of Saccharomyces cerevisiae. Our findings support previous studies, which stipulate that PE21 alters the lipid composition of yeast cells. PE21 markedly decreases the concentration of free fatty acids, thus it has been hypothesized that PE21 increases the CLS of yeast cells by decreasing the rate of liponecrosis known to be induced by free fatty acids. To further test this hypothesis, four single gene-deletion mutant strains differently affected in the metabolism of free fatty acids have been studied. More specifically, the lipid compositions and viabilities of such mutant strains were analyzed in yeast cultured in the presence or absence of PE21, and the results were compared to the results for wild-type strain.
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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.002 |
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".