scholarly journals Overexpression of Notch Signaling Induces Hyperosteogeny in Zebrafish

2019 ◽  
Vol 20 (15) ◽  
pp. 3613 ◽  
Author(s):  
Sung-Tzu Liang ◽  
Jung-Ren Chen ◽  
Jhih-Jie Tsai ◽  
Yu-Heng Lai ◽  
Chung-Der Hsiao

Notch signaling is one of the evolutionarily conserved signaling pathways in multicellular organisms. It plays an important role in embryonic development. During skeletal development of vertebrates, it regulates bone homeostasis by manipulating both osteoblastogenesis and osteoclastogenesis through different mechanisms. However, due to the different nature of Notch signaling in mesenchymal stem cell and osteoblast, regulation of Notch signaling in bone-related diseases remains unsettled. Previous studies by cell culture and mouse models showed contradictory results regarding the role of Notch signaling in bone homeostasis. To clarify the role of Notch signaling in osteogenesis, we established a zebrafish model, in which Notch1a intracellular domain (N1aICD) was specifically expressed in the osteoblasts. We found that overexpression of N1aICD in osteoblasts caused hyperosteogeny in the column region of zebrafish with the morphology of narrowed neural/hemal canals. Moreover, increased metabolic activity of osteoblasts instead of augmenting osteoblast number led to hyperosteogeny in N1aICD-overexpressed zebrafish. In summary, we successfully established a transgenic zebrafish line overexpressing N1aICD to clarify the in-vivo function of Notch signaling during osteoblastogenesis. In the future, this fish line can serve as a valuable tool to test the therapeutic drugs for hyperosteogeny.

2020 ◽  
Author(s):  
Cong-Jie Sun ◽  
Rong-Yin Hu ◽  
Zhi-Cao Li ◽  
Lu Jin ◽  
Chuan Ye ◽  
...  

AbstractMultidrug resistance (MDR) represents the major cause of unsatisfaction in the application of chemotherapy for cancer treatment. So far, an in vivo robust high-throughput screening system for anti-tumor drug MDR is still lacking and the molecular mechanisms for MDR still remain elusive. Given a myriad of merits of zebrafish relative to other animal models, we aimed to establish MDR system in zebrafish stably expressing ATP-binding cassette (ATP-cassette) superfamily transporters and study the potential regulatory mechanism. We first constructed a Tg(abcb4:EGFP) transgenic zebrafish stably expressing both Abcb4 and EGFP using Tol2-mediated approach. The expression level of Abcb4 and EGFP was significantly induced when Tg(abcb4:EGFP) transgenic zebrafish embryos were exposed to doxorubicin (DOX) or vincristine (VCR), accompany with a marked decrease in rhodamine B (RhB) accumulation in embryos, which indicates a remarkable increase in drug efflux upon the exposure to DOX or VCR. Mechanistically, AKT and ERK signaling were activated when treated with DOX or VCR. With the application of AKT and ERK inhibitors, the drug resistance phenomena could be reversed with differential responsive effects. Of note, downstream NF-κB played a central role in the regulation of Abcb4-mediated drug resistance. Taken together, the engineered Tg(abcb4:EGFP) transgenic zebrafish model provides a new platform for drug resistance screening in vivo, which could facilitate and accelerate the process of drug development.


Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 445
Author(s):  
Daniela Zizioli ◽  
Simona Bernardi ◽  
Marco Varinelli ◽  
Mirko Farina ◽  
Luca Mignani ◽  
...  

Zebrafish has proven to be a versatile and reliable experimental in vivo tool to study human hematopoiesis and model hematological malignancies. Transgenic technologies enable the generation of specific leukemia types by the expression of human oncogenes under specific promoters. Using this technology, a variety of myeloid and lymphoid malignancies zebrafish models have been described. Chronic myeloid leukemia (CML) is a clonal myeloproliferative neoplasia characterized by the BCR-ABL1 fusion gene, derived from the t (9;22) translocation causing the Philadelphia Chromosome (Ph). The BCR-ABL1 protein is a constitutively activated tyrosine kinas inducing the leukemogenesis and resulting in an accumulation of immature leukemic cells into bone marrow and peripheral blood. To model Ph+ CML, a transgenic zebrafish line expressing the human BCR-ABL1 was generated by the Gal4/UAS system, and then crossed with the hsp70-Gal4 transgenic line. The new line named (BCR-ABL1pUAS:CFP/hsp70-Gal4), presented altered expression of hematopoietic markers during embryonic development compared to controls and transgenic larvae showed proliferating hematopoietic cells in the caudal hematopoietic tissue (CHT). The present transgenic zebrafish would be a robust CML model and a high-throughput drug screening tool.


2010 ◽  
Vol 298 (1) ◽  
pp. L45-L56 ◽  
Author(s):  
Keli Xu ◽  
Erica Nieuwenhuis ◽  
Brenda L. Cohen ◽  
Wei Wang ◽  
Angelo J. Canty ◽  
...  

Distal lung development occurs through coordinated induction of myofibroblasts, epithelial cells, and capillaries. Lunatic Fringe ( Lfng) is a β1–3 N-acetylglucosamine transferase that modifies Notch receptors to facilitate their activation by Delta-like (Dll1/4) ligands. Lfng is expressed in the distal lung during saccular development, and deletion of this gene impairs myofibroblast differentiation and alveogenesis in this context. A similar defect was observed in Notch2 β-geo/+ Notch3 β-geo/β-geo compound mutant mice but not in Notch2 β-geo/+ or Notch3 β-geo/β-geo single mutants. Finally, to directly test for the role of Notch signaling in myofibroblast differentiation in vivo, we used ROSA26-rtTA/+; tetO-CRE/+; RBPJκflox/flox inducible mutant mice to show that disruption of canonical Notch signaling during late embryonic development prevents induction of smooth muscle actin in mesenchymal cells of the distal lung. In sum, these results demonstrate that Lfng functions to enhance Notch signaling in myofibroblast precursor cells and thereby to coordinate differentiation and mobilization of myofibroblasts required for alveolar septation.


Blood ◽  
2012 ◽  
Vol 120 (11) ◽  
pp. 2167-2173 ◽  
Author(s):  
Luke H. Hoeppner ◽  
Kathryn N. Phoenix ◽  
Karl J. Clark ◽  
Resham Bhattacharya ◽  
Xun Gong ◽  
...  

AbstractVEGF induces vascular permeability (VP) in ischemic diseases and cancer, leading to many pathophysiological consequences. The molecular mechanisms by which VEGF acts to induce hyperpermeability are poorly understood and in vivo models that easily facilitate real-time, genetic studies of VP do not exist. In the present study, we report a heat-inducible VEGF transgenic zebrafish (Danio rerio) model through which VP can be monitored in real time. Using this approach with morpholino-mediated gene knock-down and knockout mice, we describe a novel role of phospholipase Cβ3 as a negative regulator of VEGF-mediated VP by regulating intracellular Ca2+ release. Our results suggest an important effect of PLCβ3 on VP and provide a new model with which to identify genetic regulators of VP crucial to several disease processes.


2018 ◽  
Vol 55 (10) ◽  
pp. 675-684 ◽  
Author(s):  
Kun Wang ◽  
Sen Zhao ◽  
Bowen Liu ◽  
Qianqian Zhang ◽  
Yaqi Li ◽  
...  

BackgroundBrain arteriovenous malformations (BAVM) represent a congenital anomaly of the cerebral vessels with a prevalence of 10–18/100 000. BAVM is the leading aetiology of intracranial haemorrhage in children. Our objective was to identify gene variants potentially contributing to disease and to better define the molecular aetiology underlying non-syndromic sporadic BAVM.MethodsWe performed whole-exome trio sequencing of 100 unrelated families with a clinically uniform BAVM phenotype. Pathogenic variants were then studied in vivo using a transgenic zebrafish model.ResultsWe identified four pathogenic heterozygous variants in four patients, including one in the established BAVM-related gene, ENG, and three damaging variants in novel candidate genes: PITPNM3, SARS and LEMD3, which we then functionally validated in zebrafish. In addition, eight likely pathogenic heterozygous variants (TIMP3, SCUBE2, MAP4K4, CDH2, IL17RD, PREX2, ZFYVE16 and EGFR) were identified in eight patients, and 16 patients carried one or more variants of uncertain significance. Potential oligogenic inheritance (MAP4K4 with ENG, RASA1 with TIMP3 and SCUBE2 with ENG) was identified in three patients. Regulation of sma- and mad-related proteins (SMADs) (involved in bone morphogenic protein (BMP)/transforming growth factor beta (TGF-β) signalling) and vascular endothelial growth factor (VEGF)/vascular endotheliual growth factor recepter 2 (VEGFR2) binding and activity (affecting the VEGF signalling pathway) were the most significantly affected biological process involved in the pathogenesis of BAVM.ConclusionsOur study highlights the specific role of BMP/TGF-β and VEGF/VEGFR signalling in the aetiology of BAVM and the efficiency of intensive parallel sequencing in the challenging context of genetically heterogeneous paradigm.


Blood ◽  
2010 ◽  
Vol 116 (15) ◽  
pp. 2803-2811 ◽  
Author(s):  
Kevin B. Walters ◽  
Julie M. Green ◽  
Jill C. Surfus ◽  
Sa Kan Yoo ◽  
Anna Huttenlocher

Abstract CXCR4 is a G protein–coupled chemokine receptor that has been implicated in the pathogenesis of primary immunodeficiency disorders and cancer. Autosomal dominant gain-of-function truncations of CXCR4 are associated with warts, hypo-gammaglobulinemia, infections, and myelokathexis (WHIM) syndrome, a primary immunodeficiency disorder characterized by neutropenia and recurrent infections. Recent progress has implicated CXCR4-SDF1 (stromal cell-derived factor 1) signaling in regulating neutrophil homeostasis, but the precise role of CXCR4-SDF1 interactions in regulating neutrophil motility in vivo is not known. Here, we use the optical transparency of zebrafish to visualize neutrophil trafficking in vivo in a zebrafish model of WHIM syndrome. We demonstrate that expression of WHIM mutations in zebrafish neutrophils induces neutrophil retention in hematopoietic tissue, impairing neutrophil motility and wound recruitment. The neutrophil retention signal induced by WHIM truncation mutations is SDF1 dependent, because depletion of SDF1 with the use of morpholino oligonucleotides restores neutrophil chemotaxis to wounds. Moreover, localized activation of a genetically encoded, photoactivatable Rac guanosine triphosphatase is sufficient to direct migration of neutrophils that express the WHIM mutation. The findings suggest that this transgenic zebrafish model of WHIM syndrome may provide a valuable tool to screen for agents that modify CXCR4-SDF1 retention signals.


Endocrinology ◽  
2012 ◽  
Vol 153 (7) ◽  
pp. 3537-3548 ◽  
Author(s):  
J. H. Duncan Bassett ◽  
John G. Logan ◽  
Alan Boyde ◽  
Moira S. Cheung ◽  
Holly Evans ◽  
...  

Calcineurin-nuclear factor of activated T cells signaling controls the differentiation and function of osteoclasts and osteoblasts, and regulator of calcineurin-2 (Rcan2) is a physiological inhibitor of this pathway. Rcan2 expression is regulated by T3, which also has a central role in skeletal development and bone turnover. To investigate the role of Rcan2 in bone development and maintenance, we characterized Rcan2−/− mice and determined its skeletal expression in T3 receptor (TR) knockout and thyroid-manipulated mice. Rcan2−/− mice had normal linear growth but displayed delayed intramembranous ossification, impaired cortical bone formation, and reduced bone mineral accrual during development as well as increased mineralization of adult bone. These abnormalities resulted from an isolated defect in osteoblast function and are similar to skeletal phenotypes of mice lacking the type 2 deiodinase thyroid hormone activating enzyme or with dominant-negative mutations of TRα, the predominant TR isoform in bone. Rcan2 mRNA was expressed in primary osteoclasts and osteoblasts, and its expression in bone was differentially regulated in TRα and TRβ knockout and thyroid-manipulated mice. However, in primary osteoblast cultures, T3 treatment did not affect Rcan2 mRNA expression or nuclear factor of activated T cells c1 expression and phosphorylation. Overall, these studies establish that Rcan2 regulates osteoblast function and its expression in bone is regulated by thyroid status in vivo.


2018 ◽  
Author(s):  
Laura Andrés-Delgado ◽  
Alexander Ernst ◽  
María Galardi-Castilla ◽  
David Bazaga ◽  
Marina Peralta ◽  
...  

ABSTRACTThe epicardium, the outer mesothelial layer enclosing the myocardium, plays key roles in heart development and regeneration. During embryogenesis it arises from the proepicardium (PE), a cell cluster that appears in the dorsal pericardium close to the venous pole of the heart. Little is known about how the PE emerges from the pericardial mesothelium. Using the zebrafish model and a combination of genetic tools, pharmacological agents and quantitative in vivo imaging we reveal that a coordinated collective movement of the dorsal pericardium drives PE formation. We found that PE cells are apically extruded in response to actomyosin activity. Our results reveal that the coordinated action of Notch/Bmp pathways is critically needed for apical extrusion of PE cells. More generally, by comparison to cell extrusion for the elimination of unfit cells from epithelia, our results describe a unique mechanism where extruded cell viability is maintained.


2017 ◽  
Author(s):  
Kentaro Ohkuni ◽  
Reuben Levy-Myers ◽  
Jack Warren ◽  
Wei-Chun Au ◽  
Yoshimitsu Takahashi ◽  
...  

AbstractStringent regulation of cellular levels of evolutionarily conserved centromeric histone H3 variant (CENP-A in humans, CID in flies, Cse4 in yeast) prevents its mislocalization to non-centromeric chromatin. Overexpression and mislocalization of CENP-A has been observed in cancers and leads to aneuploidy in yeast, flies, and human cells. Ubiquitin-mediated proteolysis of Cse4 by E3 ligases such as Psh1 and Sumo-Targeted Ubiquitin Ligase (STUbL) Slx5 prevent mislocalization of Cse4. Previously, we identified Siz1 and Siz2 as the major E3 ligases for sumoylation of Cse4. In this study, we identify lysine 65 (K65) in Cse4 as a SUMO site and show that sumoylation of Cse4 K65 regulates its ubiquitin-mediated proteolysis by Slx5. Strains expressing cse4 K65R exhibit reduced levels of sumoylated and ubiquitinated Cse4 in vivo. Furthermore, co-immunoprecipitation experiments reveal reduced interaction of cse4 K65R with Slx5. Defects in sumoylation of cse4 K65R contribute to increased stability and mislocalization of cse4 K65R under normal physiological conditions. Based on the increased stability of cse4 K65R in psh1∆ strains but not in slx5∆ strains, we conclude that Slx5 targets sumoylated Cse4 K65 for ubiquitination-mediated proteolysis independent of Psh1. In summary, we have identified and characterized the physiological role of Cse4 sumoylation and determined that sumoylation of Cse4 K65 regulates ubiquitin-mediated proteolysis and prevents mislocalization of Cse4 which is required for genome stability.


2020 ◽  
Author(s):  
Hai-Xiong Xia ◽  
Yan-Hua Zhou ◽  
Yuan-Yuan Tuo ◽  
Ping-Ping Ren ◽  
Jin Song ◽  
...  

AbstractGlucose-6-phosphate dehydrogenase (G6PD) deficiency, the most common genetic defect and enzymopathy with a wide distribution and increased public health concern, predisposes subjects succumb to oxidative stress. G6PD deficiency has been associated with hemolysis. Clinically, G6PD deficiency is asymptomatic and the clinical manifestations occur with the exposure to certain agents. Due to the lack of suitable animal models that can predict the clinical hemolytic potential of drugs, it needs an appropriate research model to fully recapitulate the manifestations of G6PD deficiency in clinic, to optimize the malaria therapy and promote anti-malarias development. The present study has displayed a stable transgenic Tg(zgata1-g6pdM118-144-egfp) zebrafish model with G6PD deficiency which mimics the clinical features of G6PD deficiency phenotypically and functionally. The findings showed that there was an inadequate level of reduced GSH in the transgenic Tg(zgata1-g6pdM118-144-egfp) zebrafish line in the presence or absence of α-naphthol, compared to the wildtype zebrafish, indicating an attenuation of g6pd activity in the transgenic zebrafish line. In addition, the observations show that there is a less abundance of g6pd in the transgenic Tg(zgata1-g6pdM118-144-egfp) zebrafish line. On the other hand, there is no morphological abnormality in the transgenic Tg(zgata1-g6pdM118-144-egfp) zebrafish line. Taken together, our work has delivered a novel stable transgenic zebrafish model of G6PD deficiency that will facilitate the mechanistic and functional elucidation for the role of G6PD in erythrocytic pathophysiology. This model will promote the translational research for the drug development, in particular, for anti-malarias development.


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