scholarly journals Hox13 genes are required for mesoderm formation and axis elongation during early zebrafish development

Development ◽  
2020 ◽  
Vol 147 (22) ◽  
pp. dev185298
Author(s):  
Zhi Ye ◽  
David Kimelman
Keyword(s):  
Retinoic Acid ◽  
Essential Role ◽  
Vertebrate Development ◽  
Loss Of Function ◽  
The People ◽  
Vertebrate Embryo ◽  
Mesoderm Formation ◽  
Axis Elongation ◽  
Null Mutants

ABSTRACTThe early vertebrate embryo extends from anterior to posterior due to the addition of neural and mesodermal cells from a neuromesodermal progenitor (NMp) population located at the most posterior end of the embryo. In order to produce mesoderm throughout this time, the NMps produce their own niche, which is high in Wnt and low in retinoic acid. Using a loss-of-function approach, we demonstrate here that the two most abundant Hox13 genes in zebrafish have a novel role in providing robustness to the NMp niche by working in concert with the niche-establishing factor Brachyury to allow mesoderm formation. Mutants lacking both hoxa13b and hoxd13a in combination with reduced Brachyury activity have synergistic posterior body defects, in the strongest case producing embryos with severe mesodermal defects that phenocopy brachyury null mutants. Our results provide a new way of understanding the essential role of the Hox13 genes in early vertebrate development.This article has an associated ‘The people behind the papers’ interview.

scholarly journals The essential role of the transporter ABCG2 in the pathophysiology of erythropoietic protoporphyria

2019 ◽  
Vol 5 (9) ◽  
pp. eaaw6127 ◽  
Author(s):  
Pengcheng Wang ◽  
Madhav Sachar ◽  
Jie Lu ◽  
Amina I. Shehu ◽  
Junjie Zhu ◽  
...  
Keyword(s):  
Essential Role ◽  
Protoporphyrin Ix ◽  
Heme Biosynthesis ◽  
Biosynthesis Pathway ◽  
Efflux Transporter ◽  
Inherited Disease ◽  
Loss Of Function ◽  
Erythropoietic Protoporphyria

Erythropoietic protoporphyria (EPP) is an inherited disease caused by loss-of-function mutations of ferrochelatase, an enzyme in the heme biosynthesis pathway that converts protoporphyrin IX (PPIX) into heme. PPIX accumulation in patients with EPP leads to phototoxicity and hepatotoxicity, and there is no cure. Here, we demonstrated that the PPIX efflux transporter ABCG2 (also called BCRP) determines EPP-associated phototoxicity and hepatotoxicity. We found that ABCG2 deficiency decreases PPIX distribution to the skin and therefore prevents EPP-associated phototoxicity. We also found that ABCG2 deficiency protects against EPP-associated hepatotoxicity by modulating PPIX distribution, metabolism, and excretion. In summary, our work has uncovered an essential role of ABCG2 in the pathophysiology of EPP, which suggests the potential for novel strategies in the development of therapy for EPP.

scholarly journals RES complex is associated with intron definition and required for zebrafish early embryogenesis

2017 ◽  
Author(s):  
Juan P. Fernandez ◽  
Miguel A. Moreno-Mateos ◽  
Andre Gohr ◽  
Shun Hang Chan ◽  
Manuel Irimia ◽  
...  
Keyword(s):  
Rna Binding ◽  
Rna Binding Proteins ◽  
Mrna Splicing ◽  
Vertebrate Development ◽  
Loss Of Function ◽  
Recognition Elements ◽  
Splicing Patterns ◽  
The Brain ◽  
Intron Definition

AbstractPre-mRNA splicing is a critical step of gene expression in eukaryotes. Transcriptome-wide splicing patterns are complex and primarily regulated by a diverse set of recognition elements and associated RNA-binding proteins. The retention and splicing (RES) complex is formed by three different proteins (Bud13p, Pml1p and Snu17p) and is involved in splicing in yeast. However, the importance of the RES complex for vertebrate splicing, the intronic features associated with its activity, and its role in development are unknown. In this study, we have generated loss-of-function mutants for the three components of the RES complex in zebrafish and showed that they are required during early development. The mutants showed a marked neural phenotype with increased cell death in the brain and a decrease in differentiated neurons. Transcriptomic analysis of bud13, snip1 (pml1) and rbmx2 (snu17) mutants revealed a global defect in intron splicing, with strong mis-splicing of a subset of introns. We found these RES-dependent introns were short, rich in GC and flanked by GC depleted exons, all of which are features associated with intron definition. Using these features we developed a predictive model that classifies RES dependent introns. Altogether, our study uncovers the essential role of the RES complex during vertebrate development and provides new insights into its function during splicing.

scholarly journals Brain and Breast Cancer Cells with PTEN Loss of Function Demonstrate Enhanced Durotaxis and RHOB Dependent Amoeboid Migration Using 3D Printed Scaffolds and Aligned Microfiber Tracts

2021 ◽  
Author(s):  
Annalena Wieland ◽  
Pamela L. Strissel ◽  
Hannah Schorle ◽  
Ezgi Bakirci ◽  
Dieter Janzen ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Morphology ◽  
Live Cell Imaging ◽  
Essential Role ◽  
Cell Imaging ◽  
Loss Of Function ◽  
Pten Loss ◽  
3D Printed ◽  
And Migration

Abstract Background: Glioblastoma multiforme (GBM) and triple-negative breast cancer (TNBC) with PTEN mutations often lead to brain dissemination with very poor patient outcomes. GBM uses axons and vessels as migratory cues to disseminate, however it is not known, if TNBC shares the same behavior. There is a need to understand brain tumor cell spreading and if GBM and TNBC have similar migration properties involving the signaling pathway RHOB-ROCK-PTEN. We tested for durotaxis, adherence and migration of GBM and TNBC using live-cell imaging and performed molecular analyses on three-dimensional (3D) structures.Methods: Aligned 3D printed scaffolds and microfibers were designed to mimic brain axon tracts and vessels for migration. GBM and TNBC cell lines, each with opposing PTEN genotypes, were analysed with RHO, ROCK and PTEN inhibitors and rescuing PTEN function using live-cell imaging. RNA-sequencing and qPCR of tumor cells in 3D with microfibers were performed, while SEM, confocal microscopy and cell tracking addressed cell morphology. Results: GBM and TNBC with homozygote PTEN loss of function and RHOB high expression were amoeboid shaped and demonstrated enhanced durotaxis, adhesion and migration on 3D microfibers, in contrast to PTEN wildtype GBM and TNBC showing elongated cells and low RHOB. RNA-sequencing exhibited that RHOB was significantly the highest expressed gene in GBM PTEN loss of function cells. Pathway inhibitors and PTEN rescue of function verified an essential role of RHOB-ROCK-PTEN signaling for durotaxis, adhesion, migration, cell morphology and plasticity using 3D printed microfibers. Conclusions: This study validates a significant role of a PTEN genotype for cellular properties including durotaxis, adhesion and migration. GBM and TNBC cells with PTEN loss of function have a greater affinity for stiffer brain structures promoting metastasis. We propose the significance of PTEN and RHOB in cellular oncology not only for primary tumors, but also for metastasizing tumors, where RHOB inhibitors could play an essential role for improved therapy.

scholarly journals MondoA regulates gene expression in cholesterol biosynthesis-associated pathways required for zebrafish epiboly

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Meltem Weger ◽  
Benjamin D Weger ◽  
Andrea Schink ◽  
Masanari Takamiya ◽  
Johannes Stegmaier ◽  
...  
Keyword(s):  
Cholesterol Biosynthesis ◽  
Glucose Sensing ◽  
Embryonic Cell ◽  
Vertebrate Development ◽  
Downregulated Gene ◽  
Loss Of Function ◽  
Hormone Metabolism ◽  
Metabolic Genes ◽  
Expression Of Genes

The glucose-sensing Mondo pathway regulates expression of metabolic genes in mammals. Here, we characterized its function in the zebrafish and revealed an unexpected role of this pathway in vertebrate embryonic development. We showed that knockdown of mondoa impaired the early morphogenetic movement of epiboly in zebrafish embryos and caused microtubule defects. Expression of genes in the terpenoid backbone and sterol biosynthesis pathways upstream of pregnenolone synthesis was coordinately downregulated in these embryos, including the most downregulated gene nsdhl. Loss of Nsdhl function likewise impaired epiboly, similar to MondoA loss of function. Both epiboly and microtubule defects were partially restored by pregnenolone treatment. Maternal-zygotic mutants of mondoa showed perturbed epiboly with low penetrance and compensatory changes in the expression of terpenoid/sterol/steroid metabolism genes. Collectively, our results show a novel role for MondoA in the regulation of early vertebrate development, connecting glucose, cholesterol and steroid hormone metabolism with early embryonic cell movements.

scholarly journals The essential role of PRAK in tumor metastasis and its therapeutic potential

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yuqing Wang ◽  
Wei Wang ◽  
Haoming Wu ◽  
Yu Zhou ◽  
Xiaodan Qin ◽  
...  
Keyword(s):  
Tumor Metastasis ◽  
Essential Role ◽  
Therapeutic Potential ◽  
Lung Metastases ◽  
Breast Cancers ◽  
Loss Of Function ◽  
Apparent Effect ◽  
Metastatic Risk ◽  
Pronounced Inhibition

AbstractMetastasis is the leading cause of cancer-related death. Despite the recent advancements in cancer treatment, there is currently no approved therapy for metastasis. The present study reveals a potent and selective activity of PRAK in the regulation of tumor metastasis. While showing no apparent effect on the growth of primary breast cancers or subcutaneously inoculated tumor lines, Prak deficiency abrogates lung metastases in PyMT mice or mice receiving intravenous injection of tumor cells. Consistently, PRAK expression is closely associated with metastatic risk in human cancers. Further analysis indicates that loss of function of PRAK leads to a pronounced inhibition of HIF-1α protein synthesis, possibly due to reduced mTORC1 activities. Notably, pharmacological inactivation of PRAK with a clinically relevant inhibitor recapitulates the anti-metastatic effect of Prak depletion, highlighting the therapeutic potential of targeting PRAK in the control of metastasis.

scholarly journals Amnion signals are essential for mesoderm formation in primates

2020 ◽  
Author(s):  
Ran Yang ◽  
Alexander Goedel ◽  
Yu Kang ◽  
Chenyang Si ◽  
Chu Chu ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Embryonic Stem ◽  
Cellular Level ◽  
Model Systems ◽  
Loss Of Function ◽  
Primate Model ◽  
Mesoderm Formation ◽  
Human Primate

AbstractEssential genes for murine embryonic development can demonstrate a disparate phenotype in human cohorts. By generating a transcriptional atlas containing >30,000 cells from postimplantation non-human primate embryos, we discovered that ISL1, a gene with a well-established role in cardiogenesis, controls a gene regulatory network in primate amnion. CRISPR/Cas9-targeting of ISL1 resulted in non-human primate embryos which did not yield viable offspring, demonstrating that ISL1 is critically required in primate embryogenesis. On a cellular level, mutant ISL1 embryos displayed a failure in mesoderm formation due to reduced BMP4 signaling from the amnion. Via loss of function and rescue studies in human embryonic stem cells we confirmed a similar role of ISL1 in human in vitro derived amnion. This study highlights the importance of the amnion as a signaling center during primate mesoderm formation and demonstrates the potential of in vitro primate model systems to dissect the genetics of early human embryonic development.

scholarly journals Amnion signals are essential for mesoderm formation in primates

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ran Yang ◽  
Alexander Goedel ◽  
Yu Kang ◽  
Chenyang Si ◽  
Chu Chu ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Embryonic Stem ◽  
Cellular Level ◽  
Model Systems ◽  
Loss Of Function ◽  
Primate Model ◽  
Mesoderm Formation ◽  
Human Primate

AbstractEmbryonic development is largely conserved among mammals. However, certain genes show divergent functions. By generating a transcriptional atlas containing >30,000 cells from post-implantation non-human primate embryos, we uncover that ISL1, a gene with a well-established role in cardiogenesis, controls a gene regulatory network in primate amnion. CRISPR/Cas9-targeting of ISL1 results in non-human primate embryos which do not yield viable offspring, demonstrating that ISL1 is critically required in primate embryogenesis. On a cellular level, mutant ISL1 embryos display a failure in mesoderm formation due to reduced BMP4 signaling from the amnion. Via loss of function and rescue studies in human embryonic stem cells we confirm a similar role of ISL1 in human in vitro derived amnion. This study highlights the importance of the amnion as a signaling center during primate mesoderm formation and demonstrates the potential of in vitro primate model systems to dissect the genetics of early human embryonic development.

scholarly journals Cardiac Differentiation of Human Pluripotent Stem Cells Using Defined Extracellular Matrix Proteins Reveals Essential Role of Fibronectin

2021 ◽  
Author(s):  
Jianhua Zhang ◽  
Ran Tao ◽  
Pratik A. Lalit ◽  
Juliana L Carvalho ◽  
Yogananda Markandeya ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Pluripotent Stem Cells ◽  
Essential Role ◽  
Early Stage ◽  
Cardiac Differentiation ◽  
Matrix Proteins ◽  
Downstream Signaling ◽  
Mesoderm Formation ◽  
Integrin Linked Kinase

Research and therapeutic applications using human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) require robust differentiation strategies. Efforts to improve hPSC-CM differentiation have largely overlooked the role of extracellular matrix (ECM). The present study investigates the ability of defined ECM proteins to promote hPSC cardiac differentiation. Fibronectin, laminin-111, and laminin-521 enabled hPSCs to attach and expand; however, fibronectin ECM either endogenously produced or exogenously added promoted, while laminins inhibited, cardiac differentiation in response to growth factors Activin A, BMP4, and bFGF. Inducible shRNA knockdown of fibronectin prevented Brachyury+ mesoderm formation and subsequent hPSC-CM differentiation. Antibodies blocking fibronectin binding to integrin β1, but not α5, inhibited cardiac differentiation. Furthermore, inhibition of integrin-linked kinase blocked cardiac differentiation. These results identify fibronectin, laminin-111 and laminin-521 as defined substrates enabling cardiac differentiation of hPSCs and uncover the essential role of fibronectin and downstream signaling pathways in the early stage of hPSC-CM differentiation.

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