scholarly journals Differential regulation of β-catenin-mediated transcription via N- and C-terminal co-factors governs identity of murine intestinal epithelial stem cells

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Costanza Borrelli ◽  
Tomas Valenta ◽  
Kristina Handler ◽  
Karelia Vélez ◽  
Alessandra Gurtner ◽  
...  
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
Intestinal Epithelial ◽  
Epithelial Stem Cells ◽  
Unfolded Protein ◽  
Modulation Of Gene Expression ◽  
Protein Response ◽  
Transcriptional Output ◽  
Fine Tune ◽  
Stem Cell Pool

AbstractThe homeostasis of the gut epithelium relies upon continuous renewal and proliferation of crypt-resident intestinal epithelial stem cells (IESCs). Wnt/β-catenin signaling is required for IESC maintenance, however, it remains unclear how this pathway selectively governs the identity and proliferative decisions of IESCs. Here, we took advantage of knock-in mice harboring transgenic β-catenin alleles with mutations that specifically impair the recruitment of N- or C-terminal transcriptional co-factors. We show that C-terminally-recruited transcriptional co-factors of β-catenin act as all-or-nothing regulators of Wnt-target gene expression. Blocking their interactions with β-catenin rapidly induces loss of IESCs and intestinal homeostasis. Conversely, N-terminally recruited co-factors fine-tune β-catenin’s transcriptional output to ensure proper self-renewal and proliferative behaviour of IESCs. Impairment of N-terminal interactions triggers transient hyperproliferation of IESCs, eventually resulting in exhaustion of the self-renewing stem cell pool. IESC mis-differentiation, accompanied by unfolded protein response stress and immune infiltration, results in a process resembling aberrant “villisation” of intestinal crypts. Our data suggest that IESC-specific Wnt/β-catenin output requires selective modulation of gene expression by transcriptional co-factors.

scholarly journals Discrete regulation of β-catenin-mediated transcription governs identity of intestinal epithelial stem cells

2020 ◽  
Author(s):  
Costanza Borrelli ◽  
Tomas Valenta ◽  
Kristina Handler ◽  
Karelia Vélez ◽  
Giulia Moro ◽  
...  
Keyword(s):  
Stem Cells ◽  
Target Gene ◽  
Regulation Of Transcription ◽  
Intestinal Epithelial ◽  
Epithelial Stem Cells ◽  
Cell Pool ◽  
Gut Epithelium ◽  
Transcriptional Output ◽  
Fine Tune ◽  
Stem Cell Pool

AbstractThe homeostasis of the gut epithelium relies upon continuous renewal and proliferation of crypt-resident intestinal epithelial stem cells (IESCs). Wnt/β-catenin signaling is required for IESC maintenance, however, it remains unclear how this pathway selectively governs the identity and proliferative decisions of IESCs. Here, we demonstrate that C-terminally-recruited transcriptional co-factors of β-catenin act as all-or-nothing regulators of Wnt-target gene expression. Blocking their interactions with β-catenin rapidly induces loss of IESCs and intestinal homeostasis. Conversely, N-terminally recruited co-factors fine-tune β-catenin’s transcriptional output to ensure proper self-renewal and proliferative behaviour of IESCs. Impairment of N-terminal interactions triggers transient hyperproliferation of IESCs, eventually resulting in exhaustion of the self-renewing stem cell pool. IESC mis-differentiation, accompanied by intrinsic and extrinsic stress signalling results in a process resembling aberrant “villisation” of intestinal crypts. Our data suggest that IESC-specific Wnt/β-catenin output requires discrete regulation of transcription by transcriptional co-factors.

scholarly journals Transcriptome Analysis of Recombinant Protein Secretion by Aspergillus nidulans and the Unfolded-Protein Response In Vivo

2005 ◽  
Vol 71 (5) ◽  
pp. 2737-2747 ◽  
Author(s):  
Andrew H. Sims ◽  
Manda E. Gent ◽  
Karin Lanthaler ◽  
Nigel S. Dunn-Coleman ◽  
Stephen G. Oliver ◽  
...  
Keyword(s):  
Gene Expression ◽  
Recombinant Protein ◽  
Unfolded Protein Response ◽  
Aspergillus Nidulans ◽  
Filamentous Fungi ◽  
Protein Secretion ◽  
Unfolded Protein ◽  
The Unfolded Protein Response ◽  
Protein Response

ABSTRACT Filamentous fungi have a high capacity for producing large amounts of secreted proteins, a property that has been exploited for commercial production of recombinant proteins. However, the secretory pathway, which is key to the production of extracellular proteins, is rather poorly characterized in filamentous fungi compared to yeast. We report the effects of recombinant protein secretion on gene expression levels in Aspergillus nidulans by directly comparing a bovine chymosin-producing strain with its parental wild-type strain in continuous culture by using expressed sequence tag microarrays. This approach demonstrated more subtle and specific changes in gene expression than those observed when mimicking the effects of protein overproduction by using a secretion blocker. The impact of overexpressing a secreted recombinant protein more closely resembles the unfolded-protein response in vivo.

scholarly journals Enforced dimerization between XBP1s and ATF6f enhances the protective effects of the unfolded protein response (UPR) in models of neurodegeneration

2020 ◽  
Author(s):  
René L. Vidal ◽  
Denisse Sepulveda ◽  
Paulina Troncoso-Escudero ◽  
Paula Garcia-Huerta ◽  
Constanza Gonzalez ◽  
...  
Keyword(s):  
Gene Expression ◽  
Unfolded Protein Response ◽  
Target Genes ◽  
Cell Function ◽  
Alpha Synuclein ◽  
Protective Effects ◽  
Unfolded Protein ◽  
The Unfolded Protein Response ◽  
Protein Response

AbstractAlteration to endoplasmic reticulum (ER) proteostasis is observed on a variety of neurodegenerative diseases associated with abnormal protein aggregation. Activation of the unfolded protein response (UPR) enables an adaptive reaction to recover ER proteostasis and cell function. The UPR is initiated by specialized stress sensors that engage gene expression programs through the concerted action of the transcription factors ATF4, ATF6f, and XBP1s. Although UPR signaling is generally studied as unique linear signaling branches, correlative evidence suggests that ATF6f and XBP1s may physically interact to regulate a subset of UPR-target genes. Here, we designed an ATF6f-XBP1s fusion protein termed UPRplus that behaves as a heterodimer in terms of its selective transcriptional activity. Cell-based studies demonstrated that UPRplus has stronger an effect in reducing the abnormal aggregation of mutant huntingtin and alpha-synuclein when compared to XBP1s or ATF6 alone. We developed a gene transfer approach to deliver UPRplus into the brain using adeno-associated viruses (AAVs) and demonstrated potent neuroprotection in vivo in preclinical models of Parkinson’s and Huntington’s disease. These results support the concept where directing UPR-mediated gene expression toward specific adaptive programs may serve as a possible strategy to optimize the beneficial effects of the pathway in different disease conditions.

scholarly journals Unveiling role of Sphingosine-1-phosphate receptor 2 as a brake of epithelial stem cell proliferation and a tumor suppressor in colorectal cancer

2020 ◽  
Author(s):  
Luciana Petti ◽  
Giulia Rizzo ◽  
Federica Rubbino ◽  
Sudharshan Elangovan ◽  
Piergiuseppe Colombo ◽  
...  
Keyword(s):  
Stem Cells ◽  
Cell Proliferation ◽  
Normal Mucosa ◽  
Genetically Engineered ◽  
Colorectal Carcinogenesis ◽  
Intestinal Stem Cells ◽  
Cancer Information ◽  
Intestinal Epithelial ◽  
Epithelial Stem Cells ◽  
Mucosal Regeneration

Abstract BackgroundSphingosine-1-phosphate receptor 2 (S1PR2) mediates pleiotropic functions encompassing cell proliferation, survival, and migration, which become collectively de-regulated in cancer. Information onto whether S1PR2 participates in colorectal carcinogenesis/cancer is scanty, and we set out to fill the gap.MethodsWe screened expression changes of S1PR2 in human CRC and matched normal mucosa specimens [N = 76]. We compared CRC arising in inflammation-driven and genetically engineered models in wild-type (S1PR2+/+) and S1PR2 deficient (S1PR2−/−) mice. We reconstituted S1PR2 expression in RKO cells and assessed their growth in xenografts. Functionally, we mimicked ablation of S1PR2 in normal mucosa by treating S1PR2+/+ organoids with JTE013, and characterized intestinal epithelial stem cells isolated from S1PR2−/−Lgr5-EGFP- mice.ResultsS1PR2 expression was lost in 33% of CRC; in 55%, it was significantly decreased, only 12% retaining expression comparable to normal mucosa. Both colitis-induced and genetic Apc+/min mouse models of CRC showed a higher incidence in size and number of carcinomas and/or high-grade adenomas, with increased cell proliferation in S1PR2−/− mice compared to S1PR2+/+ controls. Loss of S1PR2 impaired mucosal regeneration, ultimately promoting the expansion of intestinal stem cells. Whereas its overexpression attenuated cell cycle progression, it reduced the phosphorylation of AKT and augmented the levels of PTEN.ConclusionsIn normal colonic crypts, S1PR2 gains expression along with intestinal epithelial cells differentiation, but not in intestinal stem cells, and contrasts intestinal tumorigenesis by promoting epithelial differentiation, preventing the expansion of stem cells and braking their malignant transformation. Targeting of S1PR2 may be of therapeutic benefit for CRC expressing high Lgr5.

scholarly journals Long non-coding RNA FAM83H-AS1 induced by adipose-derived stem cells promotes breast and pancreatic cancer cell proliferation and migration

2020 ◽  
Author(s):  
Jianing Tang ◽  
Qiuxia Cui ◽  
Dan Zhang ◽  
Xing Liao ◽  
Yan Gong ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Stem Cells ◽  
Cell Proliferation ◽  
Adipose Derived Stem Cells ◽  
Unfolded Protein ◽  
Pancreatic Cancer Cells ◽  
Cell Proliferation And Migration ◽  
And Migration ◽  
Protein Response ◽  
Proliferation And Migration

Abstract Background Stromal cells recruited to the tumor microenvironment and long non-coding RNAs (lncRNAs) in the tumor cells regulate cancer progression. However, their relationship is largely unknown. Methods In the current study, we identified the effects of lncRNA FAM83H-AS1, induced by adipose-derived stem cells (ADSCs) during tumor development, and explored the underlying mechanisms using a coculture cell model. Adipose tissues were obtained from healthy female donors, the expression of stromal markers on cell surface of expanded ADSCs were confirmed using immunofluorescence analysis. The breast and pancreatic cancer cells were cultured with or without ADSCs using 24-well transwell chamber systems with 8.0 µm pore size. Results Our results showed that FAM83H-AS1 was upregulated in breast and pancreatic cancers and associated with poor prognosis. ADSCs further induced FAM83H-AS1 and increased tumor cell proliferation via promoting G1/S transition through cyclin D1, CDK4 and CDK6. Wound healing, modified Boyden chamber and immunoblotting assays demonstrated that ADSCs induced epithelial-mesenchymal transition and migration of breast and pancreatic cancer cells in a FAM83H-AS1-dependent manner. And ADSC-induced FAM83H-AS1 increased unfolded protein response through AKT/XBP1 pathway. Conclusion In conclusion, our results indicated that ADSCs promoted breast and pancreatic cancer development via inducing cell proliferation and migration, as well as unfolded protein response through FAM83H-AS1.

scholarly journals IreA controls endoplasmic reticulum stress-induced autophagy and survival through homeostasis recovery

2018 ◽  
pp. MCB.00054-18 ◽  
Author(s):  
Eunice Domínguez-Martín ◽  
Laura Ongay-Larios ◽  
Laura Kawasaki ◽  
Olivier Vincent ◽  
Gerardo Coello ◽  
...  
Keyword(s):  
Gene Expression ◽  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Cell Survival ◽  
Eukaryotic Cell ◽  
Functional Link ◽  
Unfolded Protein ◽  
Transcriptional Changes ◽  
The Unfolded Protein Response ◽  
Protein Response

The Unfolded Protein Response (UPR) is an adaptive pathway that restores cellular homeostasis after endoplasmic reticulum (ER) stress. The ER-resident kinase/ribonuclease Ire1 is the only UPR sensor conserved during evolution. Autophagy, a lysosomal degradative pathway, also contributes to the recovery of cell homeostasis after ER-stress but the interplay between these two pathways is still poorly understood. We describe the Dictyostelium discoideum ER-stress response and characterize its single bonafide Ire1 orthologue, IreA. We found that tunicamycin (TN) triggers a gene-expression reprogramming that increases the protein folding capacity of the ER and alleviates ER protein load. Further, IreA is required for cell-survival after TN-induced ER-stress and is responsible for nearly 40% of the transcriptional changes induced by TN. The response of Dictyostelium cells to ER-stress involves the combined activation of an IreA-dependent gene expression program and the autophagy pathway. These two pathways are independently activated in response to ER-stress but, interestingly, autophagy requires IreA at a later stage for proper autophagosome formation. We propose that unresolved ER-stress in cells lacking IreA causes structural alterations of the ER, leading to a late-stage blockade of autophagy clearance. This unexpected functional link may critically affect eukaryotic cell survival under ER-stress.

Development and validation of an unfolded protein response-related gene signature to predict overall survival in HNSCC.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e18033-e18033
Author(s):  
Jun Chen ◽  
Bei Zhang
Keyword(s):  
Gene Expression ◽  
Overall Survival ◽  
Unfolded Protein Response ◽  
Cox Regression ◽  
Risk Group ◽  
Gene Signature ◽  
Related Gene ◽  
Hallmarks Of Cancer ◽  
Unfolded Protein ◽  
Protein Response

e18033 Background: Genomic expression profiles have enabled the classification of head and neck squamous cell carcinoma (HNSCC) into molecular sub-types and provide prognostic information, which have implications for the personalized treatment of HNSCC beyond clinical and pathological features. Methods: Gene-expression profiling was identified in TCGA- HNSCC (n = 492) and validated with the Gene Expression Ominibus (GEO) dataset(n = 270) for which RNA sequencing data and clinical covariates were available. A single-sample gene set enrichment analysis (ssGSEA) algorithm were used to quantified the levels of various hallmarks of cancer. And LASSO Cox regression model was used to screen robust prognostic biomarkers to identify the best set of survival-associated gene signatures in HNSCC. Statistical analyses were performed using R version 3.4.4. Results: We identified unfolded protein response as the primary risk factor for survival（cox coefficient = 17.4 [8.4-26.3], P < 0.001）among various hallmarks of cancer in TCGA- HNSCC. And unfolded protein response ssGESA scores were significantly elevated in patients who died during follow up (P = 0.009). Kaplan-Meier analysis showed that patients with low ssGSEA scores of unfolded protein response exhibited better OS (HR = 0.69, P = 0.008). And we established an unfolded protein response-related gene signature based on lasso cox. We then apply the unfolded protein response -related gene signature to classify patients into the high risk group and the low risk group with the cutoff of 0.18. Adjusted for stage，age，gender, our signature was an independent risk factor for overall survival in TCGA cohorts (HR = 0.39 [0.28-0.53],P = < 0.001). In external independent cohorts, similar results were observed. In the validation cohort GEO65858, the patients with high unfolded protein response score showed longer survival (HR = 0.62 [0.38-1.0], P = 0.049). And adjusted for stage，age，HPV state, the multivariate cox regression analysis showed that unfolded protein response-related gene signature exhibited an independent risk prediction for overall survival in 270 patients with HNSCC (HR = 0.57 [0.35-0.94], P = 0.026). Conclusions: By analyzing the gene-expression data with bioinformation approach, we developed and validated a risk prediction model with unfolded protein response -related expression scores in HNSCC, which have the potential to identify patients who could have better overall survival.

Abstract TMP33: Repair of Ischemic Intestinal Epithelial Stem Cells: Potential Therapy to Improve Stroke Outcomes

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Kathiresh Kumar Mani ◽  
Farida Sohrabji
Keyword(s):  
Stem Cells ◽  
Motor Function ◽  
Stroke Recovery ◽  
Female Rats ◽  
Stem Cell Marker ◽  
Left Middle Cerebral Artery ◽  
Intestinal Epithelial ◽  
Epithelial Stem Cells ◽  
Stroke Outcomes ◽  
Sensory Motor

Background: Nearly 50% of all stroke patients experience “leaky” gut, gut hemorrhage and gut epithelium damage. Gut leakiness may increase circulating inflammatory cytokines and other gut products such as endotoxins, which can impair stroke recovery. Here we tested the hypothesis that normalizing gut function via transplantation of intestinal epithelial stem cells (IESC) after stroke may stimulate repair of gut structures and improve stroke outcomes. Methods: Reproductive senescent female Sprague-Dawley rats used for this study and assigned to the following groups: Control (no stroke); stroke with sham transplant (vehicle); stroke with IESC transplantation. Rats were subjected to stereotaxic surgery to occlude the left middle cerebral artery by using Endothelin-1. Primary IECs were isolated from young female rats to prepare organoids cultures. Dissociated organoids were labeled with PKH26 and injected iv either once (48h after stroke) or 3 times (4h/24h/48h after stroke). Behavioral assays and saphenous blood draws were performed pre-stroke, 2d and 5d after stroke. Trunk blood, brain tissue and a segment of small intestine was collected at termination and processed for the expression of the stem cell marker Lgr5+, Na/K ATPase-α, and tight junction proteins. Results: Significant deterioration of the gut architecture was observed after stroke, including blunted or absent villi and irregular crypts. In animals that received PKH26-labeled organoid tranplants at 48h post stroke, labeled cells were seen in the center of the villus and a few organoid cells were immunositve for Lgr5+. Animals that received 3 organoid injections showed PKH26-labeled cells incorporated in both the villus and crypts. In these animals, villus were well formed and appeared no different from non-stroke controls. Sensory motor function assessed by adhesive removal test on the side contralateral to the infarction was severely impaired in the stroke/no transplant animals (120+secs/timed out), while this impairment was attenuated in the group that received 3 organoid injections (31±11 secs). Conclusion: These data suggest that transplantation of IESC after stroke may promote repair of gut villus and crypts, with a concomitant improvement in sensory motor function.

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