A65 HNF4A IS A KEY REGULATOR OF THE EPITHELIAL STEM CELL NICHE.
Bibliographic record
Abstract
HNF4α is a transcriptional factor downregulated in intestinal bowel diseases (IBD). Epithelial deletion of HNF4α in the mouse intestine leads to spontaneous intestinal inflammation. Those observations suggest that HNF4α could play an important role in epithelial homeostasis. The intestinal crypt is the functional compartment responsible for the maintenance of this homeostasis. Proliferation of stem cells is essential for the mucosa healing following injuries, while Paneth cells are important regulators of this process through the secretion of stem cell niche factors including WNT3, a key activator of the canonical WNT/β-catenin pathway. We aimed to investigate if HNF4α could play an intrinsic role in stem and Paneth cells for the maintenance of the epithelial niche in intestinal crypts. Villin-Cre/HNF4αloxp/loxp and the hydroxytamoxifen (4OHT) inducible Villin-Cre ERT2/HNF4αloxp/loxp mouse models were used in this study. Isolated crypts were processed for protein and RNA isolation. Enteroids were derived from these models and used for RNAseq and qPCR experiments. Enteroids were derived from jejunal crypts of inducible Villin-Cre ERT2/HNF4αloxp/loxp mice. Induction of HNF4α deletion with 4OHT led to degeneration of these enteroids starting 5 days after the deletion, an observation reminiscent of enteroids derived from the Villin-Cre/HNF4αloxp/loxp mouse model. EdU incorporation assays showed a decrease in the proliferative rate of enteroids 4 days following HNF4α deletion. RNAseq was next performed on RNA isolated from enteroids induced for HNF4α deletion after 2 and 4 days in culture. Transcriptomic analysis identified more than a thousand of genes differentially expressed following the deletion of HNF4α under these conditions. A significant reduction of WNT3 was predicted, an observation that was further confirmed by qPCR and Western in jejunal crypts of HNF4α mutant mice. To measure the functional relevance of WNT3 reduction during enteroids degeneration, a rescue experiment was performed. WNT3A supplementation was able to maintain HNF4α deleted enteroids in culture. Transcriptomic analysis of WNT3A-treated enteroids showed rescue for 85% of the genes identified to be modulated in enteroids deleted for HNF4α. To further verify if HNF4α may contribute to Paneth cell differentiation, enteroids committed to differentiate into the Paneth lineage were deleted for HNF4α. Gene transcript expression of Paneth cell markers (Defa3, Defa5, Defa20, Defa21-22, Lyz and WNT3) were all downregulated in the absence of HNF4α as opposed to EpHB3, which was not significantly modulated. This study identifies HNF4α as a key regulator of Paneth cell function for maintenance of the epithelial stem cell niche. These observations provide a novel mechanistic loop for which the intestinal epithelial healing process could be dependent following stress-related injuries. CIHRCCC-Vertex
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 | 0.001 | 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".