scholarly journals Cessation of contraction induces cardiomyocyte remodeling during zebrafish cardiogenesis

2014 ◽  
Vol 306 (3) ◽  
pp. H382-H395 ◽  
Author(s):  
Jingchun Yang ◽  
Katherine A. Hartjes ◽  
Timothy J. Nelson ◽  
Xiaolei Xu
Keyword(s):  
Signaling Pathways ◽  
Heart Development ◽  
Myosin Ii ◽  
Cardiac Contraction ◽  
Zebrafish Embryos ◽  
Mechanical Forces ◽  
In Vivo Animal Model ◽  
Lateral Fusion ◽  
Phosphoinositide 3 Kinase

Contraction regulates heart development via a complex mechanotransduction process controlled by various mechanical forces. Here, we exploit zebrafish embryos as an in vivo animal model to discern the contribution from different mechanical forces and identify the underlying mechanotransductive signaling pathways of cardiogenesis. We treated 2 days postfertilization zebrafish embryos with Blebbistatin, a myosin II inhibitor, to stop cardiac contraction, which induces a response termed cessation of contraction-induced cardiomyocyte (CM) enlargement (CCE). Accompanying the CCE, lateral fusion of myofibrils was attenuated within CMs. The CCE can be blunted by loss of blood in tail-docked zebrafish but not in cloche mutant fish, suggesting that transmural pressure rather than shear stress is accountable for the chamber enlargement. By screening a panel of small molecule inhibitors, our data suggested essential functions of phosphoinositide 3-kinase signaling and protein synthesis in CCE, which are independent of the sarcomere integrity. In summary, we defined a unique CCE response in genetically tractable zebrafish embryos. A panel of assays was established to verify the contribution from extrinsic forces and interrogate underlying signaling pathways.

scholarly journals Celecoxib Impairs Heart Development via  Inhibiting Cyclooxygenase-2 Activity in Zebrafish Embryos

2011 ◽  
Vol 114 (2) ◽  
pp. 391-400 ◽  
Author(s):  
Dao-jie Xu ◽  
Ji-wen Bu ◽  
Shan-ye Gu ◽  
Yi-meng Xia ◽  
Jiu-lin Du ◽  
...  
Keyword(s):  
Myosin Heavy Chain ◽  
Heart Valve ◽  
Heavy Chain ◽  
Heart Development ◽  
Heart Defects ◽  
Cyclooxygenase 2 ◽  
Confocal Imaging ◽  
Marker Genes ◽  
Zebrafish Embryos

Background Celecoxib, a cyclooxygenase-2 inhibitor, is a commonly ingested drug that is used by some women during pregnancy. Although use of celecoxib is associated with increased cardiovascular risk in adults, its effect on fetal heart development remains unknown. Methods Zebrafish embryos were exposed to celecoxib or other relevant drugs from tailbud stage (10.3-72 h postfertilization). Heart looping and valve formation were examined at different developmental stages by in vivo confocal imaging. In addition, whole mount in situ hybridization was performed to examine drug-induced changes in the expression of heart valve marker genes. Results In celecoxib-treated zebrafish embryos, the heart failed to undergo normal looping and the heart valve was absent, causing serious blood regurgitation. Furthermore, celecoxib treatment disturbed the restricted expression of the heart valve markers bone morphogenetic protein 4 and versican-but not the cardiac chamber markers cardiac myosin light chain 2, ventricular myosin heavy chain, and atrial myosin heavy chain. These defects in heart development were markedly relieved by treatment with the cyclooxygenase-2 downstream product prostaglandin E2, and mimicked by the cyclooxygenase-2 inhibitor NS398, implying that celecoxib-induced heart defects were caused by the inhibition of cyclooxygenase-2 activity. Conclusions These findings provide the first in vivo evidence that celecoxib exposure impairs heart development in zebrafish embryos by inhibiting cyclooxygenase-2 activity.

Microarray profiling revealsCXCR4ais downregulated by blood flow in vivo and mediates collateral formation in zebrafish embryos

2009 ◽  
Vol 38 (3) ◽  
pp. 319-327 ◽  
Author(s):  
Ian M. Packham ◽  
Caroline Gray ◽  
Paul R. Heath ◽  
Paul G. Hellewell ◽  
Philip W. Ingham ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cardiac Contraction ◽  
Zebrafish Embryos ◽  
Knock Down ◽  
Transcriptional Effect ◽  
Vessel Development ◽  
Hemodynamic Force ◽  
Collateral Vessels ◽  
And Control

The response to hemodynamic force is implicated in a number of pathologies including collateral vessel development. However, the transcriptional effect of hemodynamic force is extremely challenging to examine in vivo in mammals without also detecting confounding processes such as hypoxia and ischemia. We therefore serially examined the transcriptional effect of preventing cardiac contraction in zebrafish embryos which can be deprived of circulation without experiencing hypoxia since they obtain sufficient oxygenation by diffusion. Morpholino antisense knock-down of cardiac troponin T2 ( tnnt2) prevented cardiac contraction without affecting vascular development. Gene expression in whole embryo RNA from tnnt2 or control morphants at 36, 48, and 60 h postfertilization (hpf) was assessed using Affymetrix GeneChip Zebrafish Genome Arrays (>14,900 transcripts). We identified 308 differentially expressed genes between tnnt2 and control morphants. One such ( CXCR4a) was significantly more highly expressed in tnnt2 morphants at 48 and 60 hpf than controls. In situ hybridization localized CXCR4a upregulation to endothelium of both tnnt2 morphants and gridlock mutants (which have an occluded aorta preventing distal blood flow). This upregulation appears to be of functional significance as either CXCR4a knock-down or pharmacologic inhibition impaired the ability of gridlock mutants to recover blood flow via collateral vessels. We conclude absence of hemodynamic force induces endothelial CXCR4a upregulation that promotes recovery of blood flow.

scholarly journals Overexpression of Lifeact-GFP Disrupts F-Actin Organization in Cardiomyocytes and Impairs Cardiac Function

2021 ◽  
Vol 9 ◽  
Author(s):  
Rui Xu ◽  
Shaojun Du
Keyword(s):  
Actin Filament ◽  
Heart Development ◽  
Molecular Probe ◽  
Actin Dynamics ◽  
Transgenic Zebrafish ◽  
Zebrafish Embryos ◽  
Gfp Expression ◽  
Actin Organization ◽  
Cardiac Muscles

Lifeact-GFP is a frequently used molecular probe to study F-actin structure and dynamic assembly in living cells. In this study, we generated transgenic zebrafish models expressing Lifeact-GFP specifically in cardiac muscles to investigate the effect of Lifeact-GFP on heart development and its application to study cardiomyopathy. The data showed that transgenic zebrafish with low to moderate levels of Lifeact-GFP expression could be used as a good model to study contractile dynamics of actin filaments in cardiac muscles in vivo. Using this model, we demonstrated that loss of Smyd1b, a lysine methyltransferase, disrupted F-actin filament organization in cardiomyocytes of zebrafish embryos. Our studies, however, also demonstrated that strong Lifeact-GFP expression in cardiomyocytes was detrimental to actin filament organization in cardiomyocytes that led to pericardial edema and early embryonic lethality of zebrafish embryos. Collectively, these data suggest that although Lifeact-GFP is a good probe for visualizing F-actin dynamics, transgenic models need to be carefully evaluated to avoid artifacts induced by Lifeact-GFP overexpression.

scholarly journals Small Molecule Screening in Zebrafish Embryos Identifies Signaling Pathways Regulating Early Thyroid Development

2019 ◽  
Author(s):  
Benoit Haerlingen ◽  
Robert Opitz ◽  
Isabelle Vandernoot ◽  
Achim Trubiroha ◽  
Pierre Gillotay ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Small Molecule ◽  
Molecular Mechanisms ◽  
Model Organisms ◽  
Thyroid Cell ◽  
Zebrafish Embryos ◽  
Cardiovascular Development ◽  
Drug Induced ◽  
Thyroid Development

AbstractBackgroundDefects in embryonic development of the thyroid gland are a major cause for congenital hypothyroidism in human newborns but the underlying molecular mechanisms are still poorly understood. Organ development relies on a tightly regulated interplay between extrinsic signaling cues and cell intrinsic factors. At present, however, there is limited knowledge about the specific extrinsic signaling cues that regulate foregut endoderm patterning, thyroid cell specification and subsequent morphogenetic processes in thyroid development.MethodsTo begin to address this problem in a systematic way, we used zebrafish embryos to perform a series of in vivo phenotype-driven chemical genetic screens to identify signaling cues regulating early thyroid development. For this purpose, we treated zebrafish embryos during different developmental periods with a panel of small molecule compounds known to manipulate the activity of major signaling pathways and scored phenotypic deviations in thyroid, endoderm and cardiovascular development using whole mount in situ hybridization and transgenic fluorescent reporter models.ResultsSystematic assessment of drugged embryos recovered a range of thyroid phenotypes including expansion, reduction or lack of the early thyroid anlage, defective thyroid budding as well as hypoplastic, enlarged or overtly disorganized presentation of the thyroid primordium after budding. Our pharmacological screening identified BMP and FGF signaling as key factors for thyroid specification and early thyroid organogenesis, highlight the importance of low Wnt activities during early development for thyroid specification and implicate drug-induced cardiac and vascular anomalies as likely indirect mechanisms causing various forms of thyroid dysgenesis.ConclusionsBy integrating the outcome of our screening efforts with previously available information from other model organisms including Xenopus, chicken and mouse, we conclude that signaling cues regulating thyroid development appear broadly conserved across vertebrates. We therefore expect that observations made in zebrafish can inform mammalian models of thyroid organogenesis to further our understanding of the molecular mechanisms of congenital thyroid diseases.

Abstract 291: In Vitro Matured Human Embryonic Stem Cell-derived Cardiomyocytes Form Grafts With Enhanced Structure and Improved Electromechanical Integration in Injured Hearts

2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Wahiba Dhahri ◽  
Tamilla Sadikov Valdman ◽  
Beiping Qiang ◽  
Hassan Masoudpour ◽  
Eylul Ceylan ◽  
...  
Keyword(s):  
Stem Cell ◽  
Embryonic Stem Cell ◽  
Heart Development ◽  
Human Embryonic Stem Cell ◽  
Ex Vivo ◽  
Embryonic Stem ◽  
Cardiac Contraction ◽  
Structural And Functional Properties

Human embryonic stem cell-derived cardiomyocytes (hESC-CMs) have tremendous promise for application in cardiac repair, but their immature phenotype greatly limits their translational potential. The present study was designed to two hypotheses: 1) that previously reported methods to promote the maturation of hESC-CMs by culture on soft polydimethylsiloxane (PDMS) substrates can be upscaled to the quantities required for transplantation studies; and 2) that PDMS-matured hESC-CMs will stably engraft in injured hearts and form graft myocardium with enhanced structural and functional properties. First, we cultured hESC-CMs on either PDMS or tissue culture plastic (TCP) for 20 and 40 days, then phenotyped the resultant populations. All hESC-CMs were engineered to express the fluorescent voltage-sensitive protein ASAP1 to facilitate in vitro and in vivo electrophysiological studies. Relative to their counterparts on TCP, hESC-CMs on PDMS at both time-points exhibited increased cardiac gene expression as well as a more mature structural and electrophysiological phenotype in vitro. Single-cell transcriptomics confirmed enrichment of cardiac maturation markers including gene pathways involved in cardiac contraction, extracellular matrix organization, sarcomerogenesis, and adult heart development in PDMS versus TCP cultures. Next, we transplanted day 20 or 40 TCP vs PDMS ASAP1+ hESC-CMs into injured guinea pig hearts. Recipient hearts were later analyzed by ex vivo optical voltage mapping studies and histology. While CMs from both substrates showed similar capacity for engraftment, grafts formed with PDMS-matured myocytes had more mature structural properties including enhanced alignment, sarcomere lengths and maturation marker expression. Most importantly, graft formed with PDMS-matured myocytes showed improved electrophysiological properties including better host-graft electromechanical integration and more rapid and uniform propagation. We conclude that large quantities of matured hESC-CMs can indeed be economically produced by these methods. Moreover, PDMS-matured myocytes form large intramyocardial grafts with enhanced cardiac structure and electrical function, thereby establishing that maturation prior to transplantation meaningfully improves outcomes in vivo.

scholarly journals Lnk Inhibits Tpo–mpl Signaling and Tpo-mediated Megakaryocytopoiesis

2004 ◽  
Vol 200 (5) ◽  
pp. 569-580 ◽  
Author(s):  
Wei Tong ◽  
Harvey F. Lodish
Keyword(s):  
Signaling Pathways ◽  
Adaptor Protein ◽  
Mapk Signaling ◽  
Mitogen Activated Protein Kinase ◽  
Pleckstrin Homology Domain ◽  
Inhibitory Function ◽  
Enhanced Sensitivity ◽  
Mitogen Activated Protein ◽  
Phosphoinositide 3 Kinase

Thrombopoietin (Tpo) is the primary cytokine regulating megakaryocyte development and platelet production. Tpo signaling through its receptor, c-mpl, activates multiple pathways including signal transducer and activator of transcription (STAT)3, STAT5, phosphoinositide 3-kinase–Akt, and p42/44 mitogen-activated protein kinase (MAPK). The adaptor protein Lnk is implicated in cytokine receptor and immunoreceptor signaling. Here, we show that Lnk overexpression negatively regulates Tpo-mediated cell proliferation and endomitosis in hematopoietic cell lines and primary hematopoietic cells. Lnk attenuates Tpo-induced S-phase progression in 32D cells expressing mpl, and Lnk decreases Tpo-dependent megakaryocyte growth in bone marrow (BM)–derived megakaryocyte culture. Consistent with this result, we found that in both BM and spleen, Lnk-deficient mice exhibited increased numbers of megakaryocytes with increased ploidy compared with wild-type mice. In addition, Lnk-deficient megakaryocytes derived from BM and spleen showed enhanced sensitivity to Tpo during culture. The absence of Lnk caused enhanced and prolonged Tpo induction of STAT3, STAT5, Akt, and MAPK signaling pathways in CD41+ megakaryocytes. Furthermore, the Src homology 2 domain of Lnk is essential for Lnk's inhibitory function. In contrast, the conserved tyrosine near the COOH terminus is dispensable and the pleckstrin homology domain of Lnk contributes to, but is not essential for, inhibiting Tpo-dependent 32D cell growth or megakaryocyte development. Thus, Lnk negatively modulates mpl signaling pathways and is important for Tpo-mediated megakaryocytopoiesis in vivo.

scholarly journals Anti-Melanogenesis Activity of 6-O-Isobutyrylbritannilactone from Inula britannica on B16F10 Melanocytes and In Vivo Zebrafish Models

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3887
Author(s):  
Dae Kil Jang ◽  
Chau Ha Pham ◽  
Ik Soo Lee ◽  
Seung-Hyun Jung ◽  
Ji Hye Jeong ◽  
...  
Keyword(s):  
Zebrafish Embryos ◽  
Mrna Levels ◽  
Dependent Manner ◽  
B16f10 Cells ◽  
Inula Britannica ◽  
Phosphoinositide 3 Kinase ◽  
Related Proteins ◽  
Dose Dependent ◽  
Tyrosinase Expression

A potential natural melanogenesis inhibitor was discovered in the form of a sesquiterpene isolated from the flowers of Inula britannica, specifically 6-O-isobutyrylbritannilactone (IBL). We evaluated the antimelanogenesis effects of IBL on B16F10 melanocytes and zebrafish embryos. As a result, we found that 3-isobutyl-1-methylxanthine (IBMX)-induced melanin production was reduced in a dose-dependent manner in B16F10 cells by IBL. We also analyzed B16F10 cells that were and were not treated with IBMX, investigating the melanin concentration, tyrosinase activity, mRNA levels. We also studied the protein expressions of microphthalmia-associated transcription factor (MITF), tyrosinase, and tyrosinase-related proteins (TRP1, and TRP2). Furthermore, we found that melanin synthesis and tyrosinase expression were also inhibited by IBL through the modulation of the following signaling pathways: ERK, phosphoinositide 3-kinase (PI3K)/AKT, and CREB. In addition, we studied antimelanogenic activity using zebrafish embryos and found that the embryos had significantly reduced pigmentation in the IBL-treated specimens compared to the untreated controls.

scholarly journals Axenfeld-Rieger syndrome-associated mutants of the transcription factor FOXC1 abnormally regulate NKX2-5 in model zebrafish embryos

2020 ◽  
Vol 295 (33) ◽  
pp. 11902-11913
Author(s):  
Qinxin Zhang ◽  
Dong Liang ◽  
Yunyun Yue ◽  
Luqingqing He ◽  
Nan Li ◽  
...  
Keyword(s):  
Heart Development ◽  
Heart Defects ◽  
Proximal Promoter ◽  
Abnormal Development ◽  
Zebrafish Embryos ◽  
Dependent Manner ◽  
Rieger Syndrome ◽  
Dominant Disease ◽  
Direct Binding

FOXC1 is a member of the forkhead family of transcription factors, and whose function is poorly understood. A variety of FOXC1 mutants have been identified in patients diagnosed with the autosomal dominant disease Axenfeld-Rieger syndrome, which is mainly characterized by abnormal development of the eyes, particularly those who also have accompanying congenital heart defects (CHD). However, the role of FOXC1 in CHD, and how these mutations might impact FOXC1 function, remains elusive. Our previous work provided one clue to possible function, demonstrating that zebrafish foxc1a, an orthologue of human FOXC1 essential for heart development, directly regulates the expression of nkx2.5, encoding a transcriptional regulator of cardiac progenitor cells. Abnormal expression of Nkx2-5 leads to CHD in mice and is also associated with CHD patients. Whether this link extends to the human system, however, requires investigation. In this study, we demonstrate that FOXC1 does regulate human NKX2-5 expression in a dose-dependent manner via direct binding to its proximal promoter. A comparison of FOXC1 mutant function in the rat cardiac cell line H9c2 and zebrafish embryos suggested that the zebrafish embryos might serve as a more representative model system than the H9c2 cells. Finally, we noted that three of the Axenfeld-Rieger syndrome FOXC1 mutations tested increased, whereas a fourth repressed the expression of NKX2-5. These results imply that mutant FOXC1s might play etiological roles in CHD by abnormally regulating NKX2-5 in the patients. And zebrafish embryos can serve as a useful in vivo platform for rapidly evaluating disease-causing roles of mutated genes.

Identification osteogenic signaling pathways following mechanical stimulation: A systematic review

2021 ◽  
Vol 16 ◽  
Author(s):  
Hanieh Nokhbatolfoghahaei ◽  
Maryam Rezai Rad ◽  
Zahrasadat Paknejad ◽  
Abdolreza Ardeshirylajimi ◽  
Arash Khojasteh
Keyword(s):  
Signaling Pathways ◽  
Wnt Pathway ◽  
Mechanical Forces ◽  
Mechanical Stimuli ◽  
Electronic Search ◽  
Meta Analyses ◽  
Almost All ◽  
Osteogenic Signaling

Introduction: It has been shown that mechanical forces can induce or promote osteogenic differentiation as well as remodeling of the new created bone tissues. To apply this characteristic in bone tissue engineering, it is important to know which mechanical stimuli through which signaling pathway has a more significant impact on osteogenesis. Methods: In this systematic study, an electronic search was conducted using PubMed and Google Scholar databases. This study has been prepared and organized according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Included studies were first categorized according to the in vivo and in vitro studies. Results: Six types of mechanical stresses were used in these articles and the most commonly used mechanical force and cell source were tension and bone marrow-derived mesenchymal stem cells (BMMSCs), respectively. These forces were able to trigger twelve signaling pathways in which Wnt pathway was so prominent. Conclusion: 1) Although specific signaling pathways are induced through specific mechanical forces, Wnt signaling pathways are predominantly activated by almost all types of force/stimulation, 2) All signaling pathways regulate expression of RUNX2, which is known as a master regulator of osteogenesis, 3) In Tension force, the mode of force administration, i.e, continuous or non-continuous tension is more important than the percentage of elongation.

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