A43 HIGH MUC2 MUCIN BIOSYNTHESIS BY GOBLET CELLS UNDER METABOLIC STRESS PRODUCE ELEVATED LEVELS OF PRO-INFLAMMATORY CYTOKINES
Bibliographic record
Abstract
Abstract Background The colonic mucus bilayer is an integral innate host defense mechanism that houses the commensal gut microbiota whilst protecting the underlying mucosa against harmful pathogens. This essential barrier is generated via a highly ER stressful mechanism by goblet cells that produce MUC2 mucin. Goblet cells also produce a variety of proteins and peptides as well as pro-inflammatory cytokines that interact with and activate other arms of the innate immune system. In ulcerative and infectious colitis, goblet cells hyper secrete mucus and become depleted of their mucin stores. However, it is not known if other proteins or pro-inflammatory responses are altered in mucin-depleted goblet cells. Here, we elucidated the molecular mechanisms that regulate pro-inflammatory responses in WT and CRISPR/Cas9 MUC2 KO human goblet cells. Aims Hypothesis: MUC2 biosynthesis and production augment pro-inflammatory responses in goblet cells. The specific aims are: 1. To determine the pro-inflammatory responses in WT and MUC2KO goblet cells 2. To determine if the MAPK signaling pathway is altered in WT and MUC2KO goblet cells Methods mRNA and protein expression of various pro-inflammatory chemokines/cytokines in WT and CRISPR/Cas9 MUC2KO LS174T goblet cells were analyzed by RT-qPCR and 15-plex Luminex array. IL-22 was used to alleviate ER stress, as quantified by the expression of stress proteins by Western blotting. To determine differences in pro-inflammatory cytokine release, cells were stimulated with phorbol myristate acetate (PMA, positive control), live Entamoeba histolytica (Eh), and lysed soluble amebic proteins (SAP). MAPK signaling was enumerated by specific pharmacological inhibitors and analyzed by Western blotting. Results Basally and in response to live Eh, WT goblet cells expressed high levels of the metabolic stress proteins, ATF4, GRP78, and CHOP as compared to MUC2KO cells. In response to PMA, live Eh, and SAP, WT cells expressed high levels of mRNA transcripts and secreted significant amounts of the pro-inflammatory chemokines, monocyte chemoattractant protein-1 (MCP-1), interleukin-8 (IL-8), and interleukin-13 (IL-13) as compared to MUC2KO cells. Reducing ER stress with IL-22 significantly augmented IL-8 protein release in both WT and MUC2KO cells. Signaling via the ERK MAPK pathway was elevated in WT whereas in MUC2KO goblet the response was delayed. Conclusions This study demonstrates that high MUC2 mucin biosynthesis regulates the expression and secretion of the pro-inflammatory cytokines MCP-1, IL-8, and IL-13. Mechanistically, MUC2 induced metabolic stress regulated MAPK activity for high output pro-inflammatory responses as compared to MUC2KO goblet cells. Funding Agencies CIHR
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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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| 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 | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
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".