Selective disruption of neuregulin-1 function in vertebrate embryos using ribozyme-tRNA transgenes

Development ◽  
1998 ◽  
Vol 125 (10) ◽  
pp. 1899-1907 ◽  
Author(s):  
J.J. Zhao ◽  
G. Lemke
Keyword(s):  
Growth Factors ◽  
Cell Types ◽  
Erbb Receptors ◽  
Retinal Ganglion ◽  
Hammerhead Ribozymes ◽  
Neuregulin 1 ◽  
Polypeptide Growth Factors ◽  
Developing Heart ◽  
The Central Nervous System

The products of the neuregulin-1 gene constitute a set of polypeptide growth factors whose signalling through the ErbB receptors is essential to the growth and differentiation of many cell types in culture. Although studies with neuregulin-1 mutant mice have demonstrated that these growth factors are also essential regulators of cellular differentiation in vivo, the mid-embryonic death of these mutants precludes an analysis of hypothesized neuregulin-1 roles in later aspects of development. To circumvent this early lethality, we have pursued a ribozyme-based strategy for the perturbation of neuregulin-1 function in developing chick embryos. Early administration of a retrovirus carrying neuregulin-1 hammerhead-type ribozymes to blastoderm-stage embryos leads to an embryonic lethal phenotype that results from the failure of ventricular trabeculation in the developing heart, a faithful phenocopy of the mouse neuregulin-1 mutations. Later, more localized delivery of the ribozyme to the developing retina inhibits both the differentiation of retinal ganglion cell neurons and the proliferation of the neuroepithelial cells from which they derive. These results suggest that neuregulin-1 promotes both muscle cell differentiation in the heart and neuronal differentiation in the central nervous system. In addition, they demonstrate the utility of hammerhead ribozymes as a simple, effective and easily adaptable method of conditional gene inactivation in vertebrates.

scholarly journals Spatial receptive field properties of rat retinal ganglion cells

2011 ◽  
Vol 28 (5) ◽  
pp. 403-417 ◽  
Author(s):  
WALTER F. HEINE ◽  
CHRISTOPHER L. PASSAGLIA
Keyword(s):  
Receptive Field ◽  
Ganglion Cell ◽  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Cell Types ◽  
Quantitative Information ◽  
Retinal Ganglion ◽  
X And Y Cells ◽  
Y Cells

AbstractThe rat is a popular animal model for vision research, yet there is little quantitative information about the physiological properties of the cells that provide its brain with visual input, the retinal ganglion cells. It is not clear whether rats even possess the full complement of ganglion cell types found in other mammals. Since such information is important for evaluating rodent models of visual disease and elucidating the function of homologous and heterologous cells in different animals, we recorded from rat ganglion cells in vivo and systematically measured their spatial receptive field (RF) properties using spot, annulus, and grating patterns. Most of the recorded cells bore likeness to cat X and Y cells, exhibiting brisk responses, center-surround RFs, and linear or nonlinear spatial summation. The others resembled various types of mammalian W cell, including local-edge-detector cells, suppressed-by-contrast cells, and an unusual type with an ON–OFF surround. They generally exhibited sluggish responses, larger RFs, and lower responsiveness. The peak responsivity of brisk-nonlinear (Y-type) cells was around twice that of brisk-linear (X-type) cells and several fold that of sluggish cells. The RF size of brisk-linear and brisk-nonlinear cells was indistinguishable, with average center and surround diameters of 5.6 ± 1.3 and 26.4 ± 11.3 deg, respectively. In contrast, the center diameter of recorded sluggish cells averaged 12.8 ± 7.9 deg. The homogeneous RF size of rat brisk cells is unlike that of cat X and Y cells, and its implication regarding the putative roles of these two ganglion cell types in visual signaling is discussed.

Heparin stimulates the proliferation of intestinal epithelial cells in primary culture

1994 ◽  
Vol 107 (2) ◽  
pp. 401-411
Author(s):  
N. Flint ◽  
F.L. Cove ◽  
G.S. Evans
Keyword(s):  
Growth Factors ◽  
Heparan Sulphate ◽  
Primary Cultures ◽  
Cell Types ◽  
Heparin Binding ◽  
Epithelial Proliferation ◽  
Inhibition Of Proliferation ◽  
Trophic Effect ◽  
Heparin Binding Growth Factors

Heparin is a sulphated glycosaminoglycan derived from mast cells and has a number of functions including the inhibition of proliferation in several cell types and interactions with a range of heparin-binding growth factors. We report that heparin is a trophic factor in primary cultures of rat small intestinal epithelium. Heparin elicits a dose-dependent increase in epithelial proliferation and inhibits the growth of associated mesenchyme. The trophic effect of this molecule is not reproduced by other glycosaminoglycans including heparan sulphate but is dependent upon extensive molecular sulphation. Highly sulphated polysaccharides that are structurally unrelated to heparin (e.g. dextran sulphate and pentosan polysulphate) also stimulate epithelial proliferation in primary cultures. Heparin may act by the potentiation of mesenchyme-derived heparin-binding growth factors and these data suggest an in vivo role for mast cell-derived heparin in mucosal wound regeneration.

scholarly journals Intranasal Borna Disease Virus (BoDV-1) Infection: Insights into Initial Steps and Potential Contagiosity

2019 ◽  
Vol 20 (6) ◽  
pp. 1318 ◽  
Author(s):  
Alexandra Kupke ◽  
Sabrina Becker ◽  
Konstantin Wewetzer ◽  
Barbara Ahlemeyer ◽  
Markus Eickmann ◽  
...  
Keyword(s):  
Viral Infections ◽  
Cell Types ◽  
Nerve Fibers ◽  
Olfactory Pathway ◽  
Adult Rats ◽  
The Central Nervous System ◽  
Receptor Neurons

Mammalian Bornavirus (BoDV-1) typically causes a fatal neurologic disorder in horses and sheep, and was recently shown to cause fatal encephalitis in humans with and without transplant reception. It has been suggested that BoDV-1 enters the central nervous system (CNS) via the olfactory pathway. However, (I) susceptible cell types that replicate the virus for successful spread, and (II) the role of olfactory ensheathing cells (OECs), remained unclear. To address this, we studied the intranasal infection of adult rats with BoDV-1 in vivo and in vitro, using olfactory mucosal (OM) cell cultures and the cultures of purified OECs. Strikingly, in vitro and in vivo, viral antigen and mRNA were present from four days post infection (dpi) onwards in the olfactory receptor neurons (ORNs), but also in all other cell types of the OM, and constantly in the OECs. In contrast, in vivo, BoDV-1 genomic RNA was only detectable in adult and juvenile ORNs, nerve fibers, and in OECs from 7 dpi on. In vitro, the rate of infection of OECs was significantly higher than that of the OM cells, pointing to a crucial role of OECs for infection via the olfactory pathway. Thus, this study provides important insights into the transmission of neurotropic viral infections with a zoonotic potential.

scholarly journals Decreased TNF Levels and Improved Retinal Ganglion Cell Survival in MMP-2 Null Mice Suggest a Role for MMP-2 as TNF Sheddase

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Lies De Groef ◽  
Manuel Salinas-Navarro ◽  
Griet Van Imschoot ◽  
Claude Libert ◽  
Roosmarijn E. Vandenbroucke ◽  
...  
Keyword(s):  
Ganglion Cell ◽  
Retinal Ganglion Cell ◽  
Retinal Ganglion ◽  
Spatiotemporal Expression ◽  
Retinal Ganglion Cell Death ◽  
The Central Nervous System ◽  
Retinal Ganglion Cell Survival ◽  
Ganglion Cell Death

Matrix metalloproteinases (MMPs) have been designated as both friend and foe in the central nervous system (CNS): while being involved in many neurodegenerative and neuroinflammatory diseases, their actions appear to be indispensable to a healthy CNS. Pathological conditions in the CNS are therefore often related to imbalanced MMP activities and disturbances of the complex MMP-dependent protease network. Likewise, in the retina, various studies in animal models and human patients suggested MMPs to be involved in glaucoma. In this study, we sought to determine the spatiotemporal expression profile of MMP-2 in the excitotoxic retina and to unravel its role during glaucoma pathogenesis. We reveal that intravitreal NMDA injection induces MMP-2 expression to be upregulated in the Müller glia. Moreover, MMP-2 null mice display attenuated retinal ganglion cell death upon excitotoxic insult to the retina, which is accompanied by normal glial reactivity, yet reduced TNF levels. Hence, we propose a novelin vivofunction for MMP-2, as an activating sheddase of tumor necrosis factor (TNF). Given the pivotal role of TNF as a proinflammatory cytokine and neurodegeneration-exacerbating mediator, these findings generate important novel insights into the pathological processes contributing to glaucomatous neurodegeneration and into the interplay of neuroinflammation and neurodegeneration in the CNS.

scholarly journals A projection specific logic to sampling visual inputs in mouse superior colliculus

2018 ◽  
Author(s):  
Katja Reinhard ◽  
Chen Li ◽  
Quan Do ◽  
Emily Burke ◽  
Steven Heynderickx ◽  
...  
Keyword(s):  
Superior Colliculus ◽  
Ganglion Cells ◽  
Ex Vivo ◽  
Sensory Information ◽  
Cell Types ◽  
Brain Regions ◽  
Visual Response ◽  
Retinal Ganglion ◽  
Parabigeminal Nucleus

AbstractUsing sensory information to trigger different behaviours relies on circuits that pass-through brain regions. However, the rules by which parallel inputs are routed to different downstream targets is poorly understood. The superior colliculus mediates a set of innate behaviours, receiving input from ~30 retinal ganglion cell types and projecting to behaviourally important targets including the pulvinar and parabigeminal nucleus. Combining transsynaptic circuit tracing with in-vivo and ex-vivo electrophysiological recordings we observed a projection specific logic where each collicular output pathway sampled a distinct set of retinal inputs. Neurons projecting to the pulvinar or parabigeminal nucleus uniquely sampled 4 and 7 cell types, respectively. Four others innervated both pathways. The visual response properties of retinal ganglion cells correlated well with those of their disynaptic targets. These findings suggest that projection specific sampling of retinal inputs forms a mechanistic basis for the selective triggering of visually guided behaviours by the superior colliculus.

scholarly journals Single-cell profiles of retinal neurons differing in resilience to injury reveal neuroprotective genes

2019 ◽  
Author(s):  
Nicholas M. Tran ◽  
Karthik Shekhar ◽  
Irene E. Whitney ◽  
Anne Jacobi ◽  
Inbal Benhar ◽  
...  
Keyword(s):  
Single Cell ◽  
Ganglion Cells ◽  
Morphological Changes ◽  
Retinal Ganglion ◽  
Nerve Crush ◽  
Adult Retina ◽  
Neuronal Types ◽  
The Central Nervous System ◽  
Differential Gene

SummaryNeuronal types in the central nervous system differ dramatically in their resilience to injury or insults. Here we studied the selective resilience of mouse retinal ganglion cells (RGCs) following optic nerve crush (ONC), which severs their axons and leads to death of ~80% of RGCs within 2 weeks. To identify expression programs associated with differential resilience, we first used single-cell RNA-seq (scRNA-seq) to generate a comprehensive molecular atlas of 46 RGC types in adult retina. We then tracked their survival after ONC, characterized transcriptomic, physiological, and morphological changes that preceded degeneration, and identified genes selectively expressed by each type. Finally, using loss- and gain-of-function assays in vivo, we showed that manipulating some of these genes improved neuronal survival and axon regeneration following ONC. This study provides a systematic framework for parsing type-specific responses to injury, and demonstrates that differential gene expression can be used to reveal molecular targets for intervention.

scholarly journals A projection specific logic to sampling visual inputs in mouse superior colliculus

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Katja Reinhard ◽  
Chen Li ◽  
Quan Do ◽  
Emily G Burke ◽  
Steven Heynderickx ◽  
...  
Keyword(s):  
Superior Colliculus ◽  
Ex Vivo ◽  
Sensory Information ◽  
Cell Types ◽  
Brain Regions ◽  
Biased Sampling ◽  
Visual Response ◽  
Retinal Ganglion ◽  
Parabigeminal Nucleus

Using sensory information to trigger different behaviors relies on circuits that pass through brain regions. The rules by which parallel inputs are routed to downstream targets are poorly understood. The superior colliculus mediates a set of innate behaviors, receiving input from >30 retinal ganglion cell types and projecting to behaviorally important targets including the pulvinar and parabigeminal nucleus. Combining transsynaptic circuit tracing with in vivo and ex vivo electrophysiological recordings, we observed a projection-specific logic where each collicular output pathway sampled a distinct set of retinal inputs. Neurons projecting to the pulvinar or the parabigeminal nucleus showed strongly biased sampling from four cell types each, while six others innervated both pathways. The visual response properties of retinal ganglion cells correlated well with those of their disynaptic targets. These findings open the possibility that projection-specific sampling of retinal inputs forms a basis for the selective triggering of behaviors by the superior colliculus.

scholarly journals The potential roles of neurotrophins in male reproduction

Reproduction ◽  
2013 ◽  
Vol 145 (4) ◽  
pp. R89-R95 ◽  
Author(s):  
Chunjin Li ◽  
Xu Zhou
Keyword(s):  
Growth Factors ◽  
Cell Growth ◽  
Cell Types ◽  
Male Reproduction ◽  
Testicular Development ◽  
Cellular Distribution ◽  
Polypeptide Growth Factors ◽  
Growing Body ◽  
Neuronal Tissues ◽  
Existing Data

Neurotrophins are a family of polypeptide growth factors that are required for the proliferation, differentiation, survival, and death of neuronal cells. A growing body of evidence suggests that they may have broader physiological roles in various non-neuronal tissues. The testicles are complex non-neuronal organs in which diverse cell types interact to achieve correct spermatogenesis. Both neurotrophins and their receptors have been detected in various cell types from mammalian testes, suggesting that neurotrophins may regulate or mediate intercellular communication within this organ. This review summarizes the existing data on the cellular distribution and possible biological roles of neurotrophins in the testes. The data reported in the literature indicate that neurotrophins affect somatic cell growth and spermatogenesis and imply that they play a role in regulating testicular development and male reproduction.

Heterozygous knockout of neuregulin-1 gene in mice exacerbates doxorubicin-induced heart failure

2005 ◽  
Vol 289 (2) ◽  
pp. H660-H666 ◽  
Author(s):  
Fen-Fen Liu ◽  
James R. Stone ◽  
Adam J. T. Schuldt ◽  
Katashi Okoshi ◽  
Marina P. Okoshi ◽  
...  
Keyword(s):  
Cardiac Development ◽  
Cardiac Injury ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Erbb Receptors ◽  
Lv Function ◽  
Neuregulin 1 ◽  
Protein Levels ◽  
Kaplan Meier

Neuregulins and their erbB receptors are essential for cardiac development and postulated to be cardioprotective in the presence of injury in the postnatal heart. We tested the hypothesis that the development of doxorubicin-induced cardiotoxicity in vivo is more severe in mice with heterozygous knockout of the neuregulin-1 gene (NRG-1+/−) compared with wild-type mice (WT). Three-month old NRG-1+/− and WT mice were injected with a single dose of doxorubicin (20 mg/kg ip). Survival was analyzed by the Kaplan-Meier approach. Left ventricular (LV) function and signaling pathways were analyzed 4 days after treatment. Fifteen days after treatment, survival was significantly lower in doxorubicin-treated NRG-1+/− mice (NRG-1+/−-Dox) compared with doxorubicin-treated WT mice (WT-Dox) (15% vs. 33%, P < 0.01). LV mass was significantly lower in NRG-1+/−-Dox but not in WT-Dox compared with nontreated animals. LV systolic pressure and LV midwall fractional shortening were significantly lower in NRG-1+/−-Dox compared with WT-Dox mice. LV protein levels of NRG-1, erbB2, and erbB4 receptors were similar in WT-Dox and NRG-1+/−-Dox mice. However, levels of phosphorylated erbB2, Akt, and ERK-1/2 were significantly decreased in NRG-1+/−-Dox compared with WT-Dox mice. A significant decrease in phosphorylated P70S6K levels was also observed in NRG-1+/−-Dox compared with nontreated NRG-1+/− mice. These results demonstrate that heterozygous knockout of the neuregulin-1 gene worsens survival and LV function in the presence of doxorubicin-induced cardiac injury in vivo. This is associated with the depression of activation of the erbB2 receptor as well as Akt, p70S6K, and ERK-1/2 pathways.

scholarly journals Chemokines and chemokine receptors in the brain: implication in neuroendocrine regulation

2007 ◽  
Vol 38 (3) ◽  
pp. 355-363 ◽  
Author(s):  
Céline Callewaere ◽  
Ghazal Banisadr ◽  
William Rostène ◽  
Stéphane Mélik Parsadaniantz
Keyword(s):  
Chemokine Receptors ◽  
Cell Types ◽  
Normal Brain ◽  
Ability To Act ◽  
The Central Nervous System ◽  
Neuronal Functions ◽  
The Brain ◽  
Neuroendocrine Functions

Chemokines are small secreted proteins that chemoattract and activate immune and non-immune cells both in vivo and in vitro. In addition to their well-established role in the immune system, several recent reports have suggested that chemokines and their receptors may also play a role in the central nervous system (CNS). The best known central action is their ability to act as immunoinflammatory mediators. Indeed, these proteins regulate leukocyte infiltration in the brain during inflammatory and infectious diseases. However, we and others recently demonstrated that they are expressed not only in neuroinflammatory conditions, but also constitutively by different cell types including neurons in the normal brain, suggesting that they may act as modulators of neuronal functions. The goal of this review is to highlight the role of chemokines in the control of neuroendocrine functions. First, we will focus on the expression of chemokines and their receptors in the CNS, with the main spotlight on the neuronal expression in the hypothalamo–pituitary system. Secondly, we will discuss the role – we can now suspect – of chemokines and their receptors in the regulation of neuroendocrine functions. In conclusion, we propose that chemokines can be added to the well-described neuroendocrine regulatory mechanisms, providing an additional fine modulatory tuning system in physiological conditions.

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