scholarly journals Hedgehog Signaling in Pancreas Epithelium Regulates Embryonic Organ Formation and Adult  -Cell Function

Diabetes ◽  
2010 ◽  
Vol 59 (5) ◽  
pp. 1211-1221 ◽  
Author(s):  
J. Lau ◽  
M. Hebrok
Keyword(s):  
Hedgehog Signaling ◽  
Cell Function ◽  
Organ Formation ◽  
Adult Cell ◽  
Embryonic Organ

scholarly journals Hedgehog Signaling Is Dispensable for Adult Hematopoietic Stem Cell Function

2009 ◽  
Vol 4 (6) ◽  
pp. 548-558 ◽  
Author(s):  
Jie Gao ◽  
Stephanie Graves ◽  
Ute Koch ◽  
Suqing Liu ◽  
Vladimir Jankovic ◽  
...  
Keyword(s):  
Stem Cell ◽  
Hematopoietic Stem Cell ◽  
Hedgehog Signaling ◽  
Cell Function ◽  
Hematopoietic Stem

scholarly journals Transcriptional regulation of atonal required for Drosophila larval eye development by concerted action of eyes absent, sine oculis and hedgehog signaling independent of fused kinase and cubitus interruptus

Development ◽  
2000 ◽  
Vol 127 (7) ◽  
pp. 1531-1540 ◽  
Author(s):  
T. Suzuki ◽  
K. Saigo
Keyword(s):  
Hedgehog Signaling ◽  
Specific Antigen ◽  
Photoreceptor Cells ◽  
Organ Development ◽  
Cubitus Interruptus ◽  
Eyes Absent ◽  
Organ Formation ◽  
Sine Oculis ◽  
Founder Cells ◽  
Bolwig's Organ

Bolwig's organ is the larval light-sensing system consisting of 12 photoreceptors and its development requires atonal activity. Here, we showed that Bolwig's organ formation and atonal expression are controlled by the concerted function of hedgehog, eyes absent and sine oculis. Bolwig's organ primordium was first detected as a cluster of about 14 Atonal-positive cells at the posterior edge of the ocular segment in embryos and hence, atonal expression may define the region from which a few Atonal-positive founder cells (future primary photoreceptor cells) are generated by lateral specification. In Bolwig's organ development, neural differentiation precedes photoreceptor specification, since Elav, a neuron-specific antigen, whose expression is under the control of atonal, is expressed in virtually all early-Atonal-positive cells prior to the establishment of founder cells. Neither Atonal expression nor Bolwig's organ formation occurred in the absence of hedgehog, eyes absent or sine oculis activity. Genetic and histochemical analyses indicated that (1) responsible Hedgehog signals derive from the ocular segment, (2) Eyes absent and Sine oculis act downstream of or in parallel with Hedgehog signaling and (3) the Hedgehog signaling pathway required for Bolwig's organ development is a new type and lacks Fused kinase and Cubitus interruptus as downstream components.

scholarly journals Mathematical model of the neonatal mouse ventricular action potential

2008 ◽  
Vol 294 (6) ◽  
pp. H2565-H2575 ◽  
Author(s):  
Linda J. Wang ◽  
Eric A. Sobie
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Action Potential ◽  
Cell Function ◽  
Cell Model ◽  
Delayed Rectifier ◽  
Heart Cell ◽  
New Model ◽  
Adult Cell ◽  
Quantitative Understanding

Therapies for heart disease are based largely on our understanding of the adult myocardium. The dramatic differences in action potential (AP) shape between neonatal and adult cardiac myocytes, however, indicate that a different set of molecular interactions in neonatal myocytes necessitates different treatment for newborns. Computational modeling is useful for synthesizing data to determine how interactions between components lead to systems-level behavior, but this technique has not been used extensively to study neonatal heart cell function. We created a mathematical model of the neonatal ( day 1) mouse myocyte by modifying, on the basis of experimental data, the densities and/or formulations of ion transport mechanisms in an adult cell model. The new model reproduces the characteristic AP shape of neonatal cells, with a brief plateau phase and longer duration than the adult (action potential duration at 80% repolarization = 60.1 vs. 12.6 ms). The simulation results are consistent with experimental data, including 1) decreased density and altered inactivation of transient outward K+ currents, 2) increased delayed rectifier K+ currents, 3) Ca2+ entry through T-type as well as L-type Ca2+ channels, 4) increased Ca2+ influx through Na+/Ca2+ exchange, and 5) Ca2+ transients resulting from transmembrane Ca2+ entry rather than release from the sarcoplasmic reticulum (SR). Simulations performed with the model generated novel predictions, including increased SR Ca2+ leak and elevated intracellular Na+ concentration in neonatal compared with adult myocytes. This new model can therefore be used for testing hypotheses and obtaining a better quantitative understanding of differences between neonatal and adult physiology.

scholarly journals Hedgehog Signaling Is Dispensable for Adult Murine Hematopoietic Stem Cell Function and Hematopoiesis

2009 ◽  
Vol 4 (6) ◽  
pp. 559-567 ◽  
Author(s):  
Inga Hofmann ◽  
Elizabeth H. Stover ◽  
Dana E. Cullen ◽  
Junhao Mao ◽  
Kelly J. Morgan ◽  
...  
Keyword(s):  
Stem Cell ◽  
Hematopoietic Stem Cell ◽  
Hedgehog Signaling ◽  
Cell Function ◽  
Hematopoietic Stem ◽  
Murine Hematopoietic Stem Cell

scholarly journals ENKD1 is a centrosomal and ciliary microtubule-associated protein important for primary cilium assembly and Hedgehog signaling

2021 ◽  
Author(s):  
Fatmanur Tiryaki ◽  
Jovana Deretic ◽  
Elif Nur Firat-Karalar
Keyword(s):  
Primary Cilium ◽  
Mammalian Cells ◽  
Hedgehog Signaling ◽  
Developmental Disorders ◽  
Cell Function ◽  
Microtubule Organization ◽  
Regulatory Relationship ◽  
Cellular Assays ◽  
And Function

Centrioles and cilia are conserved, microtubule-based structures critical for cell function and development. Their structural and functional defects cause cancer and developmental disorders. How microtubules are organized into ordered structures by microtubule-associated proteins (MAPs) and tubulin modifications is best understood during mitosis but is largely unexplored for the centrioles and the ciliary axoneme, which are composed of remarkably stable microtubules that maintain their length at steady state. In particular, we know little about the identity of the centriolar and ciliary MAPs and how they work together during the assembly and maintenance of the cilium and centriole. Here, we identified Enkurin domain containing 1 (ENKD1) as a component of the centriole wall and the axoneme in mammalian cells, and showed that it has extensive proximity interactions with these compartments and MAPs. Using in vitro and cellular assays, we found that ENKD1 is a new MAP that promotes microtubule polymerization and regulates microtubule organization and stability. Consistently, overexpression of ENKD1 increased tubulin polymerization and acetylation and disrupted microtubule organization. Cells depleted for ENKD1 were defective in ciliary length and content regulation and failed to respond to Hedgehog pathway activation. Together, our results establish ENKD1 as a new centriolar and ciliary MAP that regulate primary cilium structure and function, and advances our understanding of the functional and regulatory relationship between MAPs and the primary cilium.

scholarly journals Regulation of murine normal and stress-induced erythropoiesis by Desert Hedgehog

Blood ◽  
2012 ◽  
Vol 119 (20) ◽  
pp. 4741-4751 ◽  
Author(s):  
Ching-in Lau ◽  
Susan V. Outram ◽  
José Ignacio Saldaña ◽  
Anna L. Furmanski ◽  
Johannes T. Dessens ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Hedgehog Signaling ◽  
Cell Function ◽  
Ex Vivo ◽  
Experimental Systems ◽  
Myeloid Progenitor ◽  
Mature Granulocyte ◽  
Desert Hedgehog ◽  
Deficient Mice

Abstract The function of Hedgehog signaling in hematopoiesis is controversial, with different experimental systems giving opposing results. Here we examined the role of Desert Hedgehog (Dhh) in the regulation of murine erythropoiesis. Dhh is one of 3 mammalian Hedgehog family proteins. Dhh is essential for testis development and Schwann cell function. We show, by analysis of Dhh-deficient mice, that Dhh negatively regulates multiple stages of erythrocyte differentiation. In Dhh-deficient bone marrow, the common myeloid progenitor (CMP) population was increased, but differentiation from CMP to granulocyte/macrophage progenitor was decreased, and the mature granulocyte population was decreased, compared with wild-type (WT). In contrast, differentiation from CMP to megakaryocyte/erythrocyte progenitor was increased, and the megakaryocyte/erythrocyte progenitor population was increased. In addition, we found that erythroblast populations were Dhh-responsive in vitro and ex vivo and that Dhh negatively regulated erythroblast differentiation. In Dhh-deficient spleen and bone marrow, BFU-Es and erythroblast populations were increased compared with WT. During recovery of hematopoiesis after irradiation, and under conditions of stress-induced erythropoiesis, erythrocyte differentiation was accelerated in both spleen and bone marrow of Dhh-deficient mice compared with WT.

scholarly journals Molecular analysis of coordinated bladder and urogenital organ formation by Hedgehog signaling

Development ◽  
2006 ◽  
Vol 134 (3) ◽  
pp. 525-533 ◽  
Author(s):  
R. Haraguchi ◽  
J. Motoyama ◽  
H. Sasaki ◽  
Y. Satoh ◽  
S. Miyagawa ◽  
...  
Keyword(s):  
Molecular Analysis ◽  
Hedgehog Signaling ◽  
Organ Formation

Freeze-substitution of rye grass and ragweed pollen grains

1990 ◽  
Vol 48 (3) ◽  
pp. 686-687
Author(s):  
Liza B. Martinez ◽  
Susan M. Wick
Keyword(s):  
Cell Function ◽  
Pollen Grains ◽  
Freeze Substitution ◽  
Cell Types ◽  
Rapid Freezing ◽  
Rye Grass ◽  
Acrylic Resins ◽  
Allergenic Proteins ◽  
Cold Embedding ◽  
Structural Preservation

Rapid freezing and freeze-substitution have been employed as alternatives to chemical fixation because of the improved structural preservation obtained in various cell types. This has been attributed to biomolecular immobilization derived from the extremely rapid arrest of cell function. These methods allow the elimination of conventionally used fixatives, which may have denaturing or “masking” effects on proteins. Thus, this makes them ideal techniques for immunocytochemistry, in which preservation of both ultrastructure and antigenicity are important. These procedures are also compatible with cold embedding acrylic resins which are known to increase sensitivity in immunolabelling.This study reveals how rapid freezing and freeze-substitution may prove to be useful in the study of the mobile allergenic proteins of rye grass and ragweed. Most studies have relied on the use of osmium tetroxide to achieve the necessary ultrastructural detail in pollen whereas those that omitted it have had to contend with poor overall preservation.

Confocal imaging of calcium in intact ventricular muscle provides a new view of excitation-contraction coupling

1996 ◽  
Vol 54 ◽  
pp. 738-739
Author(s):  
W.G. Wier
Keyword(s):  
Local Control ◽  
Cardiac Tissue ◽  
Cell Function ◽  
Isolated Heart ◽  
Cardiac Cells ◽  
Confocal Imaging ◽  
Ion Concentration ◽  
Heart Cell ◽  
Free Calcium ◽  
Heart Cells

A fundamentally new understanding of cardiac excitation-contraction (E-C) coupling is being developed from recent experimental work using confocal microscopy of single isolated heart cells. In particular, the transient change in intracellular free calcium ion concentration ([Ca2+]i transient) that activates muscle contraction is now viewed as resulting from the spatial and temporal summation of small (∼ 8 μm3), subcellular, stereotyped ‘local [Ca2+]i-transients' or, as they have been called, ‘calcium sparks'. This new understanding may be called ‘local control of E-C coupling'. The relevance to normal heart cell function of ‘local control, theory and the recent confocal data on spontaneous Ca2+ ‘sparks', and on electrically evoked local [Ca2+]i-transients has been unknown however, because the previous studies were all conducted on slack, internally perfused, single, enzymatically dissociated cardiac cells, at room temperature, usually with Cs+ replacing K+, and often in the presence of Ca2-channel blockers. The present work was undertaken to establish whether or not the concepts derived from these studies are in fact relevant to normal cardiac tissue under physiological conditions, by attempting to record local [Ca2+]i-transients, sparks (and Ca2+ waves) in intact, multi-cellular cardiac tissue.

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