The ESRP1-GPR137 axis contributes to intestinal pathogenesis
- University of Bern, Switzerland
- University Hospital Zurich, Switzerland
- Inselspital, Bern University Hospital, University of Bern, Switzerland
- University of Texas Southwestern Medical Center, United States
- The Scripps Research Institute, United States
Figures
Figure 1 with 1 supplement
Esrp1Triaka leads to altered mRNA splicing and reduced epithelial cell proliferation.
To quantify exon splicing, HEK-293 cells were co-transfected with a vector encoding Esrp1WT or Esrp1Triaka or an empty control (CTRL) vector and with an exon trap construct containing (A) Cd44 …
Figure 1—figure supplement 1
Mapping of the Triaka mutation.
(A) The Triaka mutation was mapped based on the hyperactivity and circling phenotype of the strain to proximal Chromosome 4, with a peak LOD score of 2.71 at D4Mit235. (B) The Triaka mutation causes …
Figure 2 with 1 supplement
Esrp1Triaka alters mRNA splicing patterns in colonic intestinal epithelial cells.
(A) RNA sequencing analysis was performed on colonic intestinal epithelial cells (cIECs) isolated from WT and Triaka mice. Dot plot indicating the relative difference in isoform usage for a given …
-
Figure 2—source data 1
Altered ratios of transcript isoforms in Triaka epithelial cells.
- https://doi.org/10.7554/eLife.28366.007
Figure 2—figure supplement 1
CD44 expression in Triaka and WT colons.
Immunohistochemistry was performed on colonic tissue of indicated mice to detect total CD44 (CD44t) or CD44v4. Representative pictures are shown. Scale bars: 50 µm (magnification of data shown in Fig…
Figure 3 with 3 supplements
Esrp1Triaka decreases the barrier function of the intestine.
(A) Representative flow cytometry plot of colonic single cells stained for EpCAM and CD45 (left panel). Representative histogram indicating surface E-cadherin expression on EpCAM+ epithelial cells …
-
Figure 3—source data 1
Gene expression and pathway analysis.
- https://doi.org/10.7554/eLife.28366.012
Figure 3—figure supplement 1
Esrp1Triaka alters the expression of genes associated with cell proliferation.
RNA sequencing data were used to perform a gene set enrichment analysis using the SetRank method. LogFC plots show genes that are differently expressed in Triaka versus WT colonic intestinal …
Figure 3—figure supplement 2
Normal colonic histomorphology in Triaka mice.
Intestinal sections of WT and Triaka mice. (A) Representative H&E-stained sections of the large intestine. (B) Colonic crypt depth was measured on H&E stained sections (n = 6 mice per group). (C) …
Figure 3—figure supplement 3
Normal small intestinal barrier integrity, fecal lipocalin-2 and albumin levels in Triaka mice.
(A) Barrier resistance in the small intestine tissue of WT and Triaka was measured using an Ussing chamber (n = 6 mice per group). Fecal pellets of WT and Triaka animals were collected to measure …
Figure 4 with 3 supplements
Esrp1Triaka modulates the course of experimental intestinal immunopathology.
(A) WT (n = 7) and Triaka (n = 4) mice were challenged with 2% DSS in the drinking water for 7 days. Weight loss was measured daily (left panel). One representative out of four different experiments …
Figure 4—figure supplement 1
Triaka mice show increased susceptibility to experimental colitis.
(A) WT and Triaka mice were treated with 2% DSS water and disease activity score was assessed at the indicated time points (n = 4–7 mice per group). (B) Colitis score was assessed by histological …
Figure 4—figure supplement 2
More aggressive molecular signature in Triaka intestinal tumors.
WT and Triaka mice were treated with AOM/DSS. Seventy days after the first AOM injection, tumors or adjacent tumor-free (healthy) colonic tissue were homogenized and the indicated proteins were …
Figure 4—figure supplement 3
Partial EMT signature in Triaka cIECs.
Quantitative PCR was applied to measure transcript levels of (A) Cdh1, (B) Zeb1, (C) Zeb2, and (D) Esrp1 in WT and Triaka cIECs, after normalization to Gapdh expression. n = 9–14 mice per group. …
Figure 5 with 3 supplements
GPR137 isoforms differentially activate Wnt/β-catenin signaling to modulate epithelial cell function.
(A) CMT-93 IECs were transduced with vectors encoding the indicated Gpr137 isoforms or a control vector (CTRL) and live cells were counted daily by microscopy. (B) Alternatively, monolayer …
Figure 5—figure supplement 1
Gpr137 is a splicing target of ESRP1.
To quantify exon splicing, HEK-293 cells were co-transfected with a vector encoding Esrp1WT or Esrp1Triaka or an empty control (CTRL) vector and with an exon trap construct containing Gpr137 exon 2 …
Figure 5—figure supplement 2
Gpr137 isoforms differently modulate the proliferation of epithelial cells.
CMT-93 IECs were transduced with vectors encoding the indicated Gpr137 isoforms and (A) cell proliferation relative to control vector-transduced cells was measured in a WST-1 assay. (B) Transcript …
Figure 5—figure supplement 3
Reduced Wnt/β-catenin signaling in Esrp1Triaka- compared with Esrp1WT-transduced cells.
CMT-93 cells were transduced with inducible lentiviral vectors encoding Esrp1Triaka or Esrp1WT and active β-catenin was measured by flow cytometry, after treatment with 4-hydroxytamoxifen. …
Figure 6 with 2 supplements
Expression of ESRP1 and ESRP1-dependent hGPR137 isoforms is down-regulated in the diseased intestine and predicts CRC patient survival.
(A) ESRP1 transcript levels were measured in inflamed versus matched, non-inflamed intestinal biopsies from Crohn’s disease (CD) patients and normalized to EPCAM expression. Normalized ESRP1 …
-
Figure 6—source data 1
Association of (nuclear) ESRP1 expression with clinicopathological features in 185 CRC patients.
- https://doi.org/10.7554/eLife.28366.025
-
Figure 6—source data 2
Univariate and multivariate survival analysis in 185 CRC patients.
- https://doi.org/10.7554/eLife.28366.026
-
Figure 6—source data 3
Correlation of hGPR137_Short with Wnt target genes.
- https://doi.org/10.7554/eLife.28366.027
Figure 6—figure supplement 1
Expression of GPR137 isoforms in the healthy and diseased intestine.
(A) Transcript levels of ESRP1 and hGPR137_Short were measured in normal human colon tissue (n = 10) and normalized to GAPDH expression. Expression of hGPR137_Short was assessed using primers …
Figure 6—figure supplement 2
ESRP1-dependent alternative mRNA splicing is required for epithelial integrity and intestinal homeostasis.
(A) (1) The Esrp1Triaka allele generates altered mRNA splicing events. (2) Perturbation in the distribution of specific isoforms or generation of aberrant protein isoforms in epithelial cells reduce …
Author response image 1
Expression analysis of selected genes with known function for intestinal barrier integrity.
(A) RNA sequencing was performed on colonic intestinal epithelial cells (cIECs) from Triaka and WT mice to assess expression of the indicated genes (n = 4 mice per group). (B) Quantitative PCR was …
Author response image 2
Expression analysis of selected genes with known function for post-translational modification of intestinal mucus.
RNA sequencing was performed on colonic intestinal epithelial cells (cIECs) from Triaka and WT mice (n = 4 mice per group) to assess expression of the indicated genes involved in (A) glycosylation …
Author response image 3
Analysis Mucin-2 (MUC2) layer.
(A) Immunofluorescence for MUC2 (in green) was performed on colon tissue of the indicated strains. Nuclei were visualized with DAPI. Representative pictures are shown (scale bar: 100µm). (B) …
Author response image 4
Partial EMT signature in Triaka cIECs.
(A) RNA sequencing was performed on colonic intestinal epithelial cells (cIECs) from Triaka and WT mice to assess expression of the indicated epithelial or mesenchymal marker genes (n = 4 mice per …
Author response image 5
Availability of target transcripts may determine the effect of the Esrp1Triaka mutation.
Fgfr2-IIIb expression levels were measured in EPCAM+-sorted colonic intestinal epithelial cells of the indicated strains and normalized to Gapdh expression.
Intestinal epithelial cells were isolated from mice at steady-state or from animals that underwent a short 3 day-treatment with dextran sodium sulfate (indicated as “Inflammatory conditions”) (n = 9 mice per group for steady-state conditions and n = 7 mice per group during inflammation conditions. Statistics: (B) Mann-Whitney test. *, P < 0.05.
Tables
Table 1
Bacterial translocation and serum anti-commensal antibodies.
https://doi.org/10.7554/eLife.28366.013| No. of WT mice | No. of Triaka mice | p-value | |
|---|---|---|---|
| Penetration of bacteria in mucus or mucosa | |||
| 16S rRNA | 0/9 | 6/8 | 0.0023 |
| Serum anti-commensal antibodies | |||
| IgG1 | 1/10 | 7/10 | 0.0198 |
| IgG2b | 1/10 | 8/10 | 0.0055 |
-
Statistics: Fisher's exact test was performed. This table relates to Figure 3.
Table 2
Gradual loss of nuclear ESRP1 expression is associated with CRC progression
https://doi.org/10.7554/eLife.28366.028| Tissue type | Number of cases | ESRP1 expression (%) | p-value | |
|---|---|---|---|---|
| Average | Median | |||
| Normal | 26 | 75 | 75 | <0.0001 |
| Adenoma | 42 | 56.8 | 60 | |
| Carcinoma | 185 | 26.5 | 15 | |
| Lymph node metastasis | 68 | 9.1 | 0 | |
-
Statistics: Kruskal-Wallis test was performed. This table relates to Figure 6.
Author response table 1
Unaltered barrier function or mucus production/modification pathways in Triaka cIECs.
https://doi.org/10.7554/eLife.28366.035| SetID | Database | Description | Change Triaka vs. WT |
|---|---|---|---|
| GO:0070254 | GOBP | mucus secretion | Not significant |
| GO:0070255 | GOBP | regulation of mucus secretion | Not significant |
| GO:0070256 | GOBP | negative regulation of mucus secretion | Not significant |
| GO:0070257 | GOBP | positive regulation of mucus secretion | Not significant |
| GO:0070701 | GOCC | mucus layer | Not significant |
| GO:0070702 | GOCC | inner mucus layer | Not significant |
| GO:0070703 | GOCC | outer mucus layer | Not significant |
| GO:0006486 | GOBP | protein glycosylation | Not significant |
| GO:0006487 | GOBP | protein N-linked glycosylation | Not significant |
| GO:0006493 | GOBP | protein O-linked glycosylation | Not significant |
| GO:0006517 | GOBP | protein deglycosylation | Not significant |
| GO:0018242 | GOBP | protein O-linked glycosylation via serine | Not significant |
| GO:0018243 | GOBP | protein O-linked glycosylation via threonine | Not significant |
| GO:0018279 | GOBP | protein N-linked glycosylation via asparagine | Not significant |
| GO:0033575 | GOBP | protein glycosylation at cell surface | Not significant |
| GO:0033577 | GOBP | protein glycosylation in endoplasmic reticulum | Not significant |
| GO:0033578 | GOBP | protein glycosylation in Golgi | Not significant |
| GO:0060049 | GOBP | regulation of protein glycosylation | Not significant |
| GO:0060050 | GOBP | positive regulation of protein glycosylation | Not significant |
| GO:0060051 | GOBP | negative regulation of protein glycosylation | Not significant |
| GO:0090283 | GOBP | regulation of protein glycosylation in Golgi | Not significant |
| GO:0090284 | GOBP | positive regulation of protein glycosylation in Golgi | Not significant |
| GO:0090285 | GOBP | negative regulation of protein glycosylation in Golgi | Not significant |
| 5894152 | Reactome | O-glycosylation of TSR domain-containing proteins | Not significant |
| GO:0070830 | GOBP | tight junction assembly | Not significant |
| GO:1902396 | GOBP | protein localization to tight junction | Not significant |
| GO:2000810 | GOBP | regulation of tight junction assembly | Not significant |
| GO:0005923 | GOCC | tight junction | Not significant |
| GO:0007045 | GOBP | cell-substrate adherens junction assembly | Not significant |
| GO:0034332 | GOBP | adherens junction organization | Not significant |
| GO:0034333 | GOBP | adherens junction assembly | Not significant |
| GO:0034334 | GOBP | adherens junction maintenance | Not significant |
| GO:0071896 | GOBP | protein localization to adherens junction | Not significant |
| GO:0005912 | GOCC | adherens junction | Not significant |
| GO:0005913 | GOCC | cell-cell adherens junction | Not significant |
| GO:0005914 | GOCC | spot adherens junction | Not significant |
| GO:0005924 | GOCC | cell-substrate adherens junction | Not significant |
Additional files
-
Supplementary file 1
Antibodies and conjugates used for flow cytometry analysis.
- https://doi.org/10.7554/eLife.28366.029
-
Supplementary file 2
Self-designed primers for qPCR analysis.
- https://doi.org/10.7554/eLife.28366.030
-
Transparent reporting form
- https://doi.org/10.7554/eLife.28366.031
