Abstract 3937: Generation and Analysis of Neural Crest- and Endothelial-specific Mutant Mice for Foxc1

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Seungwoon Seo ◽  
Hisaki Hayashi ◽  
Tsutomu Kume
Keyword(s):  
Neural Crest ◽  
Corneal Stroma ◽  
Cell Types ◽  
Mutant Mice ◽  
Specific Cell ◽  
Cardiovascular Development ◽  
Forkhead Transcription Factor ◽  
Vascular Abnormalities ◽  
Autonomous Function ◽  
Conditional Mutant

The forkhead transcription factor Foxc1 has been implicated in craniofacial, ocular and cardiovascular development. Foxc1 is expressed in mesoderm- and neural crest (NC)-derived cells, including endothelial cells (ECs) of the heart and blood vessels and vascular smooth muscle cells. However, the precise role of Foxc1 in specific cell types still remains unclear. Therefore, to define the distinct function of Foxc1 in NC and EC, we have generated conditional mutant mice for Foxc1 crossed with either Tie2-Cre or Wnt1-Cre mice. EC-specific Foxc1 mutants survive until adulthood with no apparent embryonic defects, although they show vascular abnormalities in the adult. By contrast, NC-specific Foxc1 mutants die perinately with haemorrhagic hydrocephalus, rudimentary frontal bones, and abnormal patterning of the aortic arch. NC-derived cells also give rise to the stroma and endothelium of the cornea, an avascular organ whose transparency is critical for vision. Importantly, we found that NC-specific Foxc1 mutants show failure of the formation of the anterior chamber and corneal endothelium in the eye. Mutant corneal stroma is much thicker than normal with increased cell proliferation. Most Intriguingly, NC-specific Foxc1 mutants exhibit ectopic neovascularization in the cornea with significant upregulation of Mmp9, sFlt1, Flt1 and Tek at E15.5, while Vegfa and Fgf expression is not changed. By contrast, the cornea of EC-specific Foxc1 mutants is normally formed and avascular. These data suggest that the cell-autonomous function of Foxc1 in the neural crest is essential for craniofacial and cardiovascular development and that Foxc1 plays an important role in inhibition of vascular formation in the cornea.

scholarly journals Conditional deletion of the Bcl-x gene from erythroid cells results in hemolytic anemia and profound splenomegaly

Development ◽  
2000 ◽  
Vol 127 (22) ◽  
pp. 4949-4958 ◽  
Author(s):  
K.U. Wagner ◽  
E. Claudio ◽  
E.B. Rucker ◽  
G. Riedlinger ◽  
C. Broussard ◽  
...  
Keyword(s):  
Hemolytic Anemia ◽  
Cell Types ◽  
Mutant Mice ◽  
Erythroid Cells ◽  
Bcl2 Family ◽  
Conditional Deletion ◽  
Recombination System ◽  
Conditional Mutant ◽  
X Gene ◽  
Mmtv Ltr

Bcl-x is a member of the Bcl2 family and has been suggested to be important for the survival and maturation of various cell types including the erythroid lineage. To define the consequences of Bcl-x loss in erythroid cells and other adult tissues, we have generated mice conditionally deficient in the Bcl-x gene using the Cre-loxP recombination system. The temporal and spatial excision of the floxed Bcl-x locus was achieved by expressing the Cre recombinase gene under control of the MMTV-LTR. By the age of five weeks, Bcl-x conditional mutant mice exhibited hyperproliferation of megakaryocytes and a decline in the number of circulating platelets. Three-month-old animals suffered from severe hemolytic anemia, hyperplasia of immature erythroid cells and profound enlargement of the spleen. We demonstrate that Bcl-x is only required for the survival of erythroid cells at the end of maturation, which includes enucleated reticulocytes in circulation. The extensive proliferation of immature erythroid cells in the spleen and bone marrow might be the result of a fast turnover of late red blood cell precursors and accelerated erythropoiesis in response to tissue hypoxia. The increase in cell death of late erythroid cells is independent from the proapoptotic factor Bax, as demonstrated in conditional double mutant mice for Bcl-x and Bax. Mice conditionally deficient in Bcl-x permitted us for the first time to study the effects of Bcl-x deficiency on cell proliferation, maturation and survival under physiological conditions in an adult animal.

scholarly journals DAF-16/FoxO and DAF-12/VDR control cellular plasticity both cell-autonomously and via interorgan signaling

PLoS Biology ◽  
2021 ◽  
Vol 19 (4) ◽  
pp. e3001204
Author(s):  
Ulkar Aghayeva ◽  
Abhishek Bhattacharya ◽  
Surojit Sural ◽  
Eliza Jaeger ◽  
Matthew Churgin ◽  
...  
Keyword(s):  
Nervous System ◽  
Tissue Remodeling ◽  
Cell Types ◽  
Nuclear Hormone Receptor ◽  
Specific Cell ◽  
Signaling Systems ◽  
Autonomous Function ◽  
Insulin Dependent ◽  
Adverse Environmental Conditions ◽  
Temporal Focus

Many cell types display the remarkable ability to alter their cellular phenotype in response to specific external or internal signals. Such phenotypic plasticity is apparent in the nematodeCaenorhabditis eleganswhen adverse environmental conditions trigger entry into the dauer diapause stage. This entry is accompanied by structural, molecular, and functional remodeling of a number of distinct tissue types of the animal, including its nervous system. The transcription factor (TF) effectors of 3 different hormonal signaling systems, the insulin-responsive DAF-16/FoxO TF, the TGFβ-responsive DAF-3/SMAD TF, and the steroid nuclear hormone receptor, DAF-12/VDR, a homolog of the vitamin D receptor (VDR), were previously shown to be required for entering the dauer arrest stage, but their cellular and temporal focus of action for the underlying cellular remodeling processes remained incompletely understood. Through the generation of conditional alleles that allowed us to spatially and temporally control gene activity, we show here that all 3 TFs are not only required to initiate tissue remodeling upon entry into the dauer stage, as shown before, but are also continuously required to maintain the remodeled state. We show that DAF-3/SMAD is required in sensory neurons to promote and then maintain animal-wide tissue remodeling events. In contrast, DAF-16/FoxO or DAF-12/VDR act cell-autonomously to control anatomical, molecular, and behavioral remodeling events in specific cell types. Intriguingly, we also uncover non-cell autonomous function of DAF-16/FoxO and DAF-12/VDR in nervous system remodeling, indicating the presence of several insulin-dependent interorgan signaling axes. Our findings provide novel perspectives into how hormonal systems control tissue remodeling.

The zebrafish colourless gene regulates development of non-ectomesenchymal neural crest derivatives

Development ◽  
2000 ◽  
Vol 127 (3) ◽  
pp. 515-525 ◽  
Author(s):  
R.N. Kelsh ◽  
J.S. Eisen
Keyword(s):  
Nervous System ◽  
Neural Crest ◽  
Cell Types ◽  
Pigment Cells ◽  
Specific Cell ◽  
Zebrafish Embryos ◽  
Craniofacial Skeleton ◽  
Cell Fates ◽  
Peripheral Neurons ◽  
Neural Crest Development

Neural crest forms four major categories of derivatives: pigment cells, peripheral neurons, peripheral glia, and ectomesenchymal cells. Some early neural crest cells generate progeny of several fates. How specific cell fates become specified is still poorly understood. Here we show that zebrafish embryos with mutations in the colourless gene have severe defects in most crest-derived cell types, including pigment cells, neurons and specific glia. In contrast, craniofacial skeleton and medial fin mesenchyme are normal. These observations suggest that colourless has a key role in development of non-ectomesenchymal neural crest fates, but not in development of ectomesenchymal fates. Thus, the cls mutant phenotype reveals a segregation of ectomesenchymal and non-ectomesenchymal fates during zebrafish neural crest development. The combination of pigmentation and enteric nervous system defects makes colourless mutations a model for two human neurocristopathies, Waardenburg-Shah syndrome and Hirschsprung's disease.

scholarly journals CCN2/CTGF promotor activity in the developing and adult mouse eye

2021 ◽  
Author(s):  
Andrea E. Dillinger ◽  
Sabrina Kuespert ◽  
Franziska Froemel ◽  
Ernst R. Tamm ◽  
Rudolf Fuchshofer
Keyword(s):  
Optic Nerve ◽  
Neural Crest ◽  
Optic Nerve Head ◽  
Trabecular Meshwork ◽  
Adult Mouse ◽  
Transforming Growth Factor ◽  
Amacrine Cells ◽  
Cell Types ◽  
Matricellular Protein ◽  
Specific Cell

AbstractCCN2/CTGF is a matricellular protein that is known to enhance transforming growth factor-β signaling and to induce a myofibroblast-like phenotype in a variety of cell types. Here, we investigated Ccn2/Ctgf promotor activity during development and in the adult mouse eye, using CTGFLacZ/+ mice in which the β-galactosidase reporter gene LacZ had been inserted into the open reading frame of Ccn2/Ctgf. Promotor activity was assessed by staining for β-galactosidase activity and by immunolabeling using antibodies against β-galactosidase. Co-immunostaining using antibodies against glutamine synthetase, glial fibrillary acidic protein, choline acetyltransferase, and CD31 was applied to identify specific cell types. Ccn2/Ctgf promotor activity was intense in neural crest-derived cells differentiating to corneal stroma and endothelium, and to the stroma of choroid, iris, ciliary body, and the trabecular meshwork during development. In the adult eye, a persistent and very strong promotor activity was present in the trabecular meshwork outflow pathways. In addition, endothelial cells of Schlemm’s canal, and of retinal and choroidal vessels, retinal astrocytes, Müller glia, and starburst amacrine cells were stained. Very strong promoter activity was seen in the astrocytes of the glial lamina at the optic nerve head. We conclude that CCN2/CTGF signaling is involved in the processes that govern neural crest morphogenesis during ocular development. In the adult eye, CCN2/CTGF likely plays an important role for the trabecular meshwork outflow pathways and the glial lamina of the optic nerve head.

The acellular stroma of the chick cornea inhibits melanogenesis of the neural-crest-derived cells that colonize it.

Development ◽  
1985 ◽  
Vol 86 (1) ◽  
pp. 143-154
Author(s):  
Steven Campbell ◽  
Jonathan B. L. Bard
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Extracellular Matrix ◽  
Neural Crest ◽  
Corneal Stroma ◽  
Cell Types ◽  
Brown Pigment ◽  
Transmission Electron ◽  
Wide Range

Neural crest (NC) cells from the periorbital mesenchyme (POM) invade the acellular stroma of the chick cornea at stage 27 of development (∼6 days). The invading cells become collagenproducing fibroblasts while the NC cells remaining in the POM differentiate into a wide range of cell types, the most easily recognizable of which is the pigment-producing melanocyte. In this paper, we report observations on the differentiation in vitro of cells within and migrating from explants of corneal stroma and compare their behaviour with that of cells within and migrating from explants of the POM. In ∼70% of cases, POM explants produced black, eumelanin pigmentation within 2–3 days in culture and gave rise to a mixed outgrowth of fibroblasts and melanoblasts that produced brown pigment. In no case, however, did a corneal explant produce black pigment (so demonstrating that any POM contamination was negligible). However, in 28% of cultures from stage-27 and -28 corneas, some of the cells in the outgrowth contained brown pigment indistinguishable from that produced by the POM control, although the majority of the cells in each case were fibroblasts. Two lines of investigation demonstrated that this pigment was melanin: first, transmission electron microscopy showed that the pigment organelles were incompletely melanized, granular melanosomes; second, tests designed to demonstrate the presence of lipofuscin, an alternative pigment, proved negative. Migrating cells from older corneas, in contrast, showed no evidence of even the first stages of melanogenesis. These results show, first, that some of the NC cells that invade the cornea are at least bipotent and hence representative of the POM population rather than being a unique subgroup and, second, that the acellular stroma of the cornea determines the state of differentiation of the NC cells that colonize it. The results thus provide an unequivocal demonstration that extracellular matrix can induce postmigratory NC cells to differentiate into fibroblasts.

Correlative transmission and high-resolution scanning electron microscopic studies on pituitary cells

1990 ◽  
Vol 48 (3) ◽  
pp. 20-21
Author(s):  
S. Tai
Keyword(s):  
Cell Types ◽  
Depth Of Field ◽  
Secretory Cells ◽  
Specific Cell ◽  
Pituitary Cells ◽  
Electron Microscopic ◽  
3 Dimensional ◽  
Microscopic Studies ◽  
Structure And Activity ◽  
Intracellular Structure

Extensive cytological and histological research, correlated with physiological experimental analysis, have been done on the anterior pituitaries of many different vertebrates which have provided the knowledge to create the concept that specific cell types synthesize, store and release their specific hormones. These hormones are stored in or associated with granules. Nevertheless, there are still many doubts - that need further studies, specially on the ultrastructure and physiology of these endocrine cells during the process of synthesis, transport and secretion, whereas some new methods may provide the information about the intracellular structure and activity in detail.In the present work, ultrastructural study of the hormone-secretory cells of chicken pituitaries have been done by using TEM as well as HR-SEM, to correlate the informations obtained from 2-dimensional TEM micrography with the 3-dimensional SEM topographic images, which have a continous surface with larger depth of field that - offers the adventage to interpretate some intracellular structures which were not possible to see using TEM.

Nanotheranostic agents for neurodegenerative diseases

2020 ◽  
Vol 4 (6) ◽  
pp. 645-675
Author(s):  
Parasuraman Padmanabhan ◽  
Mathangi Palanivel ◽  
Ajay Kumar ◽  
Domokos Máthé ◽  
George K. Radda ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Neurodegenerative Diseases ◽  
Cell Types ◽  
Specific Cell ◽  
Ageing Population ◽  
Target Tissue ◽  
Therapeutic Approaches ◽  
Surface Receptors ◽  
Theranostic Agents ◽  
Preclinical Animal Models

Neurodegenerative diseases (NDDs), including Alzheimer's disease (AD) and Parkinson's disease (PD), affect the ageing population worldwide and while severely impairing the quality of life of millions, they also cause a massive economic burden to countries with progressively ageing populations. Parallel with the search for biomarkers for early detection and prediction, the pursuit for therapeutic approaches has become growingly intensive in recent years. Various prospective therapeutic approaches have been explored with an emphasis on early prevention and protection, including, but not limited to, gene therapy, stem cell therapy, immunotherapy and radiotherapy. Many pharmacological interventions have proved to be promising novel avenues, but successful applications are often hampered by the poor delivery of the therapeutics across the blood-brain-barrier (BBB). To overcome this challenge, nanoparticle (NP)-mediated drug delivery has been considered as a promising option, as NP-based drug delivery systems can be functionalized to target specific cell surface receptors and to achieve controlled and long-term release of therapeutics to the target tissue. The usefulness of NPs for loading and delivering of drugs has been extensively studied in the context of NDDs, and their biological efficacy has been demonstrated in numerous preclinical animal models. Efforts have also been made towards the development of NPs which can be used for targeting the BBB and various cell types in the brain. The main focus of this review is to briefly discuss the advantages of functionalized NPs as promising theranostic agents for the diagnosis and therapy of NDDs. We also summarize the results of diverse studies that specifically investigated the usage of different NPs for the treatment of NDDs, with a specific emphasis on AD and PD, and the associated pathophysiological changes. Finally, we offer perspectives on the existing challenges of using NPs as theranostic agents and possible futuristic approaches to improve them.

Epithelial Organotypic Cultures: A Viable Model to Address Mechanisms of Carcinogenesis by Epitheliotropic Viruses

2018 ◽  
Vol 18 (4) ◽  
pp. 246-255 ◽  
Author(s):  
Lara Termini ◽  
Enrique Boccardo
Keyword(s):  
Three Dimensional ◽  
Cell Types ◽  
Experimental Models ◽  
Biological Research ◽  
Specific Gene ◽  
Specific Cell ◽  
Organotypic Cultures ◽  
Skin Physiology

In vitro culture of primary or established cell lines is one of the leading techniques in many areas of basic biological research. The use of pure or highly enriched cultures of specific cell types obtained from different tissues and genetics backgrounds has greatly contributed to our current understanding of normal and pathological cellular processes. Cells in culture are easily propagated generating an almost endless source of material for experimentation. Besides, they can be manipulated to achieve gene silencing, gene overexpression and genome editing turning possible the dissection of specific gene functions and signaling pathways. However, monolayer and suspension cultures of cells do not reproduce the cell type diversity, cell-cell contacts, cell-matrix interactions and differentiation pathways typical of the three-dimensional environment of tissues and organs from where they were originated. Therefore, different experimental animal models have been developed and applied to address these and other complex issues in vivo. However, these systems are costly and time consuming. Most importantly the use of animals in scientific research poses moral and ethical concerns facing a steadily increasing opposition from different sectors of the society. Therefore, there is an urgent need for the development of alternative in vitro experimental models that accurately reproduce the events observed in vivo to reduce the use of animals. Organotypic cultures combine the flexibility of traditional culture systems with the possibility of culturing different cell types in a 3D environment that reproduces both the structure and the physiology of the parental organ. Here we present a summarized description of the use of epithelial organotypic for the study of skin physiology, human papillomavirus biology and associated tumorigenesis.

par-4, a gene required for cytoplasmic localization and determination of specific cell types in Caenorhabditis elegans embryogenesis.

Genetics ◽  
1992 ◽  
Vol 130 (4) ◽  
pp. 771-790 ◽  
Author(s):  
D G Morton ◽  
J M Roos ◽  
K J Kemphues
Keyword(s):  
Caenorhabditis Elegans ◽  
Cell Types ◽  
Intestinal Cells ◽  
Specific Cell ◽  
Cytoplasmic Localization ◽  
Loss Of Function ◽  
Embryo Viability ◽  
Cell Stage ◽  
Maternal Genome

Abstract Specification of some cell fates in the early Caenorhabditis elegans embryo is mediated by cytoplasmic localization under control of the maternal genome. Using nine newly isolated mutations, and two existing mutations, we have analyzed the role of the maternally expressed gene par-4 in cytoplasmic localization. We recovered seven new par-4 alleles in screens for maternal effect lethal mutations that result in failure to differentiate intestinal cells. Two additional par-4 mutations were identified in noncomplementation screens using strains with a high frequency of transposon mobility. All 11 mutations cause defects early in development of embryos produced by homozygous mutant mothers. Analysis with a deficiency in the region indicates that it33 is a strong loss-of-function mutation. par-4(it33) terminal stage embryos contain many cells, but show no morphogenesis, and are lacking intestinal cells. Temperature shifts with the it57ts allele suggest that the critical period for both intestinal differentiation and embryo viability begins during oogenesis, about 1.5 hr before fertilization, and ends before the four-cell stage. We propose that the primary function of the par-4 gene is to act as part of a maternally encoded system for cytoplasmic localization in the first cell cycle, with par-4 playing a particularly important role in the determination of intestine. Analysis of a par-4; par-2 double mutant suggests that par-4 and par-2 gene products interact in this system.

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