scholarly journals Wnt signaling rescues amyloid beta induced stem cell loss

2021 ◽  
Author(s):  
Prameet Kaur ◽  
Ellora Hui Zhen Chua ◽  
Wen Kin Lim ◽  
Nathan Harmston ◽  
Nicholas S. Tolwinski
Keyword(s):  
Gene Expression ◽  
Stem Cell ◽  
Protective Effect ◽  
Wnt Signaling ◽  
Amyloid Beta ◽  
Protein Misfolding ◽  
Lithium Treatment ◽  
Amyloid Β ◽  
Cell Loss ◽  
Distinct Disease

AbstractPreviously, we established an optogenetic model to induce Amyloid-β intracellular oligomerization to model distinct disease etiologies (Limet al. 2020). Here we examine the effect of Wnt signaling on Amyloid in this model. We observe that Wnt activation rescues the detrimental effects of Amyloid expression and oligomerization. We analyze the gene expression changes downstream of Wnt that contribute to this rescue and find changes in aging related genes, protein misfolding, metabolism and inflammation. We propose that Wnt expression reduces inflammation through repression of Toll activating factors and confirm that chronic Toll activation reduces lifespan. We propose that the protective effect observed for Lithium treatment functions at least in part through Wnt activation and inhibition of inflammation.

scholarly journals TCF7L2 Silencing Reprograms the 4D Nucleome of Colorectal Cancer Cells

2020 ◽  
Author(s):  
Markus A. Brown ◽  
Gabrielle A. Dotson ◽  
Scott Ronquist ◽  
Georg Emons ◽  
Indika Rajapakse ◽  
...  
Keyword(s):  
Gene Expression ◽  
Colorectal Cancer ◽  
Time Series ◽  
Stem Cell ◽  
Wnt Signaling ◽  
Cancer Cells ◽  
Rna Sequencing ◽  
Chromatin Structure ◽  
Cell Phenotype ◽  
Colorectal Cancer Cells

AbstractCanonical Wnt signaling is crucial for intestinal homeostasis as the major Wnt signaling effector in the intestines, TCF4, is required for stem cell maintenance. The capability of TCF4 to maintain the stem cell phenotype is contingent upon β-catenin, a potent transcriptional activator which interacts with histone acetyltransferases and chromatin remodeling complexes. In colorectal cancer, mutations result in high levels of nuclear β-catenin causing aberrant cell growth. Here, we used RNAi to explore the influence of TCF4 on chromatin structure (Hi-C) and gene expression (RNA sequencing) across a 72-hour time series in colorectal cancer. We found that TCF4 reduction results in a disproportionate upregulation of gene expression genome-wide, including a powerful induction of SOX2. Hi-C analysis revealed a general increase in chromatin compaction across the entire time series, though this did not influence gene expression. Analysis of local chromosome organization demonstrated a TAD boundary loss which influenced the expression of a cluster of CEACAM genes on chromosome 19. Four-dimensional nucleome (4DN) analysis, which integrates structural (Hi-C) and functional (RNA sequencing) data, identified EMT and E2F as the two most deregulated pathways and LUM, TMPO, and AURKA as highly influential genes in these networks. Results from gene expression, chromatin structure, and centrality analyses were then integrated to generate a list of candidate transcription factors for reprogramming of colorectal cancer cells to a vulnerable state. The top ranked transcription factor in our analysis was c-JUN, an oncoprotein known to interact with TCF4 and β-catenin.

scholarly journals P085 Expression profiling of Wnt pathway genes in colon biopsies of patients with Ulcerative Colitis

2021 ◽  
Vol 15 (Supplement_1) ◽  
pp. S186-S186
Author(s):  
C Lu ◽  
D Shah ◽  
A Wijnands ◽  
B Oldenburg ◽  
W C Yeh ◽  
...  
Keyword(s):  
Gene Expression ◽  
Stem Cell ◽  
Wnt Signaling ◽  
Wnt Pathway ◽  
Target Genes ◽  
Expression Patterns ◽  
Critical Role ◽  
Epithelial Regeneration ◽  
Pathway Gene ◽  
Wnt Signal

Abstract Background There is an increasing demand of agents that can promote mucosal healing in Inflammatory Bowel Disease (IBD). Wnt/β-catenin signaling plays a critical role in epithelial regeneration and repair, and stimulating regeneration in the damaged epithelium by modulating Wnt signaling has been suggested as a potential treatment option for IBD. To guide development of Wnt modulating therapeutic molecules for IBD, an understanding of how Wnt signaling may be altered in IBD tissues is required. While earlier work showed altered Wnt pathway gene expression in UC tissues, these studies failed to consider disease conditions (moderate vs severe) and patient treatment history on expression of the Wnt family genes. These previous studies utilized RT-qPCR or microarray and did not reveal how Wnt pathway gene expression might be affected specifically in the epithelium and in the adjacent stromal stem cell niche. Here we report our work investigating expression patterns of Wnt pathway genes in UC biopsies from 12 patients with moderate and severe disease. Patients had either received no anti-TNF treatment or had gone through anti-TNF treatment and partially responded to the treatment. Methods Expression of a set of Wnt pathway genes was assessed in UC colon and rectum biopsies by RNAscope in situ hybridization and compared to expression patterns in normal control colon. The genes included the Wnt target genes AXIN2, LGR5 and RNF43, Wnt ligands and the FZD5 and LRP6 receptors enriched in the intestinal epithelium as well as key Wnt signal modulators RSPO1-4. Results Expression of Wnt target genes were mildly reduced in the UC colon epithelium, while their expression in some crypts appeared much lower. Overall expression levels of Wnt pathway genes did not differ between moderate and severe UC colon and Wnt target gene expression was more affected in the anti-TNF treated colons, which may reflect more refractory disease. Expression of FZD5, LRP6 and the key niche factor RSPO2, was reduced in the UC colon. RSPOs are normally expressed in the stromal cells next to the crypt bottom stem cell compartment but this expression pattern was disrupted in the UC colon as a result of immune cell infiltration. Although expression of Wnts was induced in the UC colon tissues, the location of expression was altered due to tissue damage, potentially making the Wnts less accessible to the intestinal stem cells. Conclusion Reduced expression of Wnt receptors, RSPOs and Wnt target genes indicate insufficient Wnt signal induction in the damaged colon epithelium of UC patients. This suggests that repair of the damaged epithelium by Wnt agonist treatment may constitute a new mechanism of action and benefit patients with UC.

scholarly journals Involvement of WNT Signaling in the Regulation of Gestational Age-Dependent Umbilical Cord-Derived Mesenchymal Stem Cell Proliferation

2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
Sota Iwatani ◽  
Akemi Shono ◽  
Makiko Yoshida ◽  
Keiji Yamana ◽  
Khin Kyae Mon Thwin ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Proliferation ◽  
Stem Cell ◽  
Wnt Signaling ◽  
Umbilical Cord ◽  
Gestational Age ◽  
Functional Difference ◽  
Stem Cell Proliferation ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation

Mesenchymal stem cells (MSCs) are a heterogeneous cell population that is isolated initially from the bone marrow (BM) and subsequently almost all tissues including umbilical cord (UC). UC-derived MSCs (UC-MSCs) have attracted an increasing attention as a source for cell therapy against various degenerative diseases due to their vigorous proliferation and differentiation. Although the cell proliferation and differentiation of BM-derived MSCs is known to decline with age, the functional difference between preterm and term UC-MSCs is poorly characterized. In the present study, we isolated UC-MSCs from 23 infants delivered at 22–40 weeks of gestation and analyzed their gene expression and cell proliferation. Microarray analysis revealed that global gene expression in preterm UC-MSCs was distinct from term UC-MSCs. WNT signaling impacts on a variety of tissue stem cell proliferation and differentiation, and its pathway genes were enriched in differentially expressed genes between preterm and term UC-MSCs. Cell proliferation of preterm UC-MSCs was significantly enhanced compared to term UC-MSCs and counteracted by WNT signaling inhibitor XAV939. Furthermore, WNT2B expression in UC-MSCs showed a significant negative correlation with gestational age (GA). These results suggest that WNT signaling is involved in the regulation of GA-dependent UC-MSC proliferation.

scholarly journals Molecular Signatures of Tumor-Initiating Cells Unveil Wnt Pathway As a Therapeutic Target in Mantle Cell Lymphoma

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 2148-2148 ◽  
Author(s):  
Felipe Samaniego ◽  
Lalit Sehgal ◽  
Frank K Braun ◽  
Zuzana Berkova ◽  
Jorge E. Romaguera ◽  
...  
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Stem Cell ◽  
Wnt Signaling ◽  
Mantle Cell Lymphoma ◽  
Wnt Pathway ◽  
Cell Lymphoma ◽  
Rt Pcr ◽  
Mantle Cell

Abstract Introduction Mantle cell lymphoma (MCL) is an aggressive and incurable form of non-Hodgkin’s lymphoma. Despite initial responses to intense chemotherapy, up to 50% of cases of MCL relapse, often in a chemoresistant form. We hypothesized that the recently identified MCL-initiating cells (MCL-ICs) are the main reason for relapse and chemoresistance of MCL. Methods We isolated MCL-ICs from primary MCL cells on the basis of a defined marker expression pattern; CD34-CD3-CD45+CD19-. The MCL-ICs, MCL-non-ICs, and peripheral blood lymphocytes from healthy donors were analyzed for gene expression using the Arraystar platform. The differences in mRNA levels of genes of interest were confirmed by quantitative RT-PCR. The prominent differentially expressed transcripts were analyzed using the Ingenuity Platform. Primary MCL cells were co-culture with mesenchymal stem cells to assess the effects of chemotherapeutic agents such as vincristine, doxorubicin and the newly approved Burton tyrosine kinase inhibitor ibrutinib, and Wnt signaling inhibitors. Results Approximately 1% of primary MCL cells are MCL-ICs and they can be maintained in co-culture with mesenchymal stem cells. Comparison of gene expression profiles of MCL-ICs and MCL-non-ICs revealed activation of stem cell-specific pathways in MCL-ICs by expression of Wnt, Notch, and Hedgehog and enhanced expression of Nanog, Oct4, KLF4, ADH1, MT1b and ABCC3. Gene expression microarray data and RT-PCR data suggested predominant activation of the Wnt/Frizzled pathway. Indeed, MCL-ICs were particularly sensitive to Wnt pathway inhibitors. Targeting Wnt-dependent β-catenin‒TCF4 interaction with CCT036477, iCRT14, or PKF118-310 preferentially eliminated the MCL-ICs, reduced the expression of stem cell transcription factors (Myc, Nanog, Oct4, Klf4), and sensitized MCL cells to vincristine, doxorubicin, and ibrutinib. Interestingly, while vincristine, doxorubicin or ibrutinib did kill MCL cells, they did not reduce the percentage of MCL-ICs in treated co-culture. Conclusion MCL-ICs are present in primary MCL isolates and they show gene expression pattern of chemoresistant, stem cell-like cells with predominant activation of Wnt signaling. In order to produce durable remissions in MCL patients, treatment strategies should be directed to target MCL-ICs. Disclosures Wang: Pharmacyclics, Janssen: Honoraria, Research Funding.

Fisiopatología de la hidrocefália idiopática de presión normal (parte 3): sistemaa glinfático

2016 ◽  
Vol 21 (2) ◽  
pp. 28-37
Author(s):  
Oscar Solís-Salgado ◽  
José Luis López-Payares ◽  
Mauricio Ayala-González
Keyword(s):  
Amyloid Beta ◽  
Interstitial Fluid ◽  
Amyloid Β ◽  
Bulk Flow ◽  
Polyethylene Glycols ◽  
Brain Interstitial Fluid ◽  
El Sistema ◽  
Arterial Pulsation ◽  
The Brain

Las vías de drenaje solutos del sistema nervioso central (SNC) participan en el recambio de liquido intersticial con el líquido cefalorraquídeo (LIT-LCR), generando un estado de homeostasis. Las alteraciones dentro de este sistema homeostático afectará la eliminación de solutos del espacio intersticial (EIT) como el péptido βa y proteína tau, los cuales son sustancias neurotóxicas para el SNC. Se han utilizado técnicas experimentales para poder analizar el intercambio LIT-LCR, las cuales revelan que este intercambio tiene una estructura bien organizada. La eliminación de solutos del SNC no tiene una estructura anatómica propiamente, se han descubierto vías de eliminación de solutos a través de marcadores florecentes en el espacio subaracnoideo, cisternas de la base y sistema ventricular que nos permiten observar una serie de vías ampliamente distribuidas en el cerebro. El LCR muestra que tiene una función linfática debido a su recambio con el LIT a lo largo de rutas paravasculares. Estos espacios que rodean la superficie arterial así como los espacios de Virchow-Robin y el pie astrocitico junto con la AQP-4, facilitan la entrada de LCR para-arterial y el aclaramiento de LIT para-venoso dentro del cerebro. El flujo y dirección que toma el LCR por estas estructuras, es conducido por la pulsación arterial. Esta función será la que finalmente llevara a la eliminación de estas sustancias neurotóxicas. En base a la dependencia de este flujo para la eliminación de sustancias se propone que el sistema sea llamado “ la Vía Glinfática”. La bibliografía así como las limitaciones que se encuentran en esta revisión están dadas por la metodología de búsqueda que ha sido realizada principalmente en PubMed utilizando los siguientes términos Mesh: Cerebral Arterial Pulsation, the brain via paravascular, drainage of amyloid-beta, bulk flow of brain interstitial fluid, radiolabeled polyethylene glycols and albumin, amyloid-β, the perivascular astroglial sheath, Brain Glymphatic Transport.

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