1193-P: Investigating the Role of Intestinal L-Cell Secretagogin in Circadian GLP-1 Secretion in a Mouse Model of Type 2 Diabetes
Bibliographic record
Abstract
The intestinal L-cell hormone Glucagon-like Peptide-1 (GLP-1) increases glucose-dependent insulin secretion and is thus used in the treatment of T2D. GLP-1 secretion from the L-cell exhibits a circadian pattern in rodents and varies by time-of-day in humans. We have shown that KD of the SNARE-regulatory protein, secretagogin (SCGN) prevents time-dependent GLP-1 release. SCGN KD in ß-cells also decreases insulin secretion and SCGN levels are reduced in T2D islets. We thus hypothesized that SCGN is decreased in the L-cell in T2D, causing alterations in the physiological pattern of GLP-1 secretion. High-fat diet, low-dose streptozotocin (HFD-STZ) mice, a model of T2D, exhibited increased fasting glucose (5.5 vs. 15.6 mmol/L; p<0.001) and decreased ß-cell area (by 75%, p<0.001). Unexpectedly, oral glucose tolerance tests conducted in 4-hour intervals through the 24-hr day showed that HFD-STZ mice exhibit a 10x increase in GLP-1 responses (400 vs. 4000 pg/ml*60 min, p<0.001) and exhibit an anti-phasic rhythm to controls. Basal GLP-1 levels remained unchanged between HFD-STZ and controls. Unexpectedly, insulin responses were not reduced in HFD-STZ mice, suggesting that increased GLP-1 levels could act as a compensatory mechanism. HFD-STZ mice also exhibited hyperglucagonemia compared to control, with increased glucagon secretion across timepoints following glucose administration (–243 vs. 800 pg/ml*60 min, p<0.001). RT-qPCR of intestinal mucosa showed an anti-phasic Scgn rhythm in the HFD-STZ model, with a 1.5-fold increase in average expression across timepoints (p<0.05), which could explain the drastically increased GLP-1 secretion. These data show that GLP-1 secretion is both increased and arrhythmic in a murine model of T2D, and that this occurs in association with an unanticipated increase in Scgn expression. Further investigation into the role of SGCN in the L-cell may serve as an avenue for therapeutics aimed at increasing endogenous GLP-1 release. Disclosure A. Biancolin: None. P. L. Brubaker: None. Funding Canadian Institutes of Health Research (PJT-15308)
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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) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.002 | 0.004 |
| Insufficient payload (model declined to judge) | 0.006 | 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".