Identification of nascent cardiovascular proteomes by cell-type-specific metabolic labeling in experimental sepsis mouse model
Bibliographic record
Abstract
BACKGROUND – Sepsis is characterized by an overwhelming systemic inflammatory response to infection that may lead to multiple organ failure and death in over 20% of the estimated 49 million annual cases worldwide. Because sepsis-related inflammatory processes disturbing cardiac and endothelial cells homeostasis are still poorly understood, only few therapeutic strategies reached added-value efficacy in terms of mortality reduction in the critical care units. Using an innovative transgenic mouse line to detect the acute changes of newly synthetized proteins, we propose to assess the protein expression profile of cardiomyocytes and endothelial cells in a murine model of polymicrobial sepsis. METHODS – The Cre-recombinase mediated expression of mutant L274G-methionyl-tRNA synthetase (MetRS*) in transgenic mouse crosses enables the selective in vivo incorporation of azidonorleucine (ANL), a non-canonical methionine analog, in newly synthetized proteins. MetRS* mice expressing CDH5-creERT2 (CDH5, endothelial cells) or αMHC-MerCreMer (MCM, cardiomyocytes) underwent CLP (cecal ligation and puncture). The sepsis model was validated by echocardiography, inflammatory cytokine profiling and histology. Labeling efficiency of nascent proteins from MCM and CDH5 cells (heart and lung) were visualized by FUNCAT (Fluorescence non-canonical amino acid tagging) or purified by BONCAT (bioorthogonal non-canonical amino acid tagging) for mass spectrometry analysis. RESULTS – Significant elevation of circulating inflammatory cytokines proves the systemic inflammatory state of mice submitted to CLP compared to SHAM mice. Our experimental model also displays a significant impairment of the LV function at both systolic (reduced cardiac index) and diastolic levels (increased E/A and isovolumic relaxation time) confirming hemodynamics alteration related to sepsis. Metascape analysis showed expression changes for several proteins involved in the acute response to stress in both MCM and CDH5 samples. Overall, nascent protein synthesis is mainly reduced in MCM samples in sepsis (14 up/98 down), something not observed in CDH5 samples both in the heart (69 up/97 down) and in the lungs (137 up/43 down). Alterations in metabolic pathways such as pyruvate metabolism and glycolysis/gluconeogenesis were only observed in MCM samples while protein associated with focal adhesion, for example, was observed in heart and lungs CDH5 samples. CONCLUSIONS – The results of this study provide a better understanding of which proteins are altered in specific cell types in a sepsis model. We confirmed previously identified markers of inflammatory response in tissues, while identifying new protein candidates and signaling pathways that may contribute to key steps of sepsis detrimental effects and thus, offering potential new therapeutic avenues to curb the fatal outcomes of this disease. Supported by Canadian Institute of Health Research (CIHR) - Project Grants (399567) This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
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 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".