scholarly journals Targeted Ablation and Reorganization of the Principal Preplate Neurons and Their Neuroblasts Identified by Golli Promoter Transgene Expression in the Neocortex of Mice

ASN NEURO ◽  
2009 ◽  
Vol 1 (4) ◽  
pp. AN20090038 ◽  
Author(s):  
Yuan-Yun Xie ◽  
Erin Jacobs ◽  
Robin Fisher
Keyword(s):  
Fluorescent Protein ◽  
Ventricular Zone ◽  
Vertical Gradient ◽  
Prenatal Development ◽  
Specific Cell ◽  
Genetic Ablation ◽  
Developing Neocortex ◽  
Total Complement ◽  
Green Fluorescent ◽  
Simplex Virus

The present study delineates the cellular responses of dorsal pallium to targeted genetic ablation of the principal preplate neurons of the neocortex. Ganciclovir treatment during prenatal development (E11-E13; where E is embryonic day) of mice selectively killed cells with shared S-phase vulnerability and targeted expression of a GPT [golli promoter transgene, linked to HSV-TK (herpes simplex virus-thymidine kinase), τ-eGFP (τ-enhanced green fluorescent protein) and lacZ (lacZ galactosidase) reporters] localized in preplate neurons. Morphogenetic fates of attacked neurons and neuroblasts, and their successors, were assessed by multiple labelling in time-series comparisons between ablated (HSV-TK+/0) and control (HSV-TK0/0) littermates. During ablation generation, neocortical growth was suppressed, and compensatory reorganization of non-GPT ventricular zone progenitors of dorsal pallium produced replacements for killed GPT neuroblasts. Replacement and surviving GPT neuroblasts then produced replacements for killed GPT neurons. Near-normal restoration of their complement delayed the settlement of GPT neurons into the reconstituted preplate, which curtailed the outgrowth of pioneer corticofugal axons. Based on this evidence, we conclude that specific cell killing in ablated mice can eliminate a major fraction of GPT neurons, with insignificant bystander killing. Also, replacement GPT neurons in ablated mice originate exclusively by proliferation from intermediate progenitor GPT neuroblasts, whose complement is maintained by non-GPT progenitors for inductive regulation of the total complement of GPT neurons. Finally, GPT neurons in both normal and ablated mice meet all morphogenetic criteria, including the ‘outside-in’ vertical gradient of settlement, presently used to identify principal preplate neurons. In ablated mice, delayed organization of these neurons desynchronizes and isolates developing neocortex from the rest of the brain, and permanently impairs its connectivity.

scholarly journals Myofibroblast Development Is Characterized by Specific Cell-Cell Adherens Junctions

2004 ◽  
Vol 15 (9) ◽  
pp. 4310-4320 ◽  
Author(s):  
B. Hinz ◽  
P. Pittet ◽  
J. Smith-Clerc ◽  
C. Chaponnier ◽  
J.-J. Meister
Keyword(s):  
Fluorescent Protein ◽  
Contractile Activity ◽  
Adherens Junctions ◽  
Smooth Muscle Actin ◽  
Flow Chamber ◽  
Dermal Fibroblasts ◽  
Mechanical Resistance ◽  
Specific Cell ◽  
Collagen Gels ◽  
Green Fluorescent

Myofibroblasts of wound granulation tissue, in contrast to dermal fibroblasts, join stress fibers at sites of cadherin-type intercellular adherens junctions (AJs). However, the function of myofibroblast AJs, their molecular composition, and the mechanisms of their formation are largely unknown. We demonstrate that fibroblasts change cadherin expression from N-cadherin in early wounds to OB-cadherin in contractile wounds, populated with α-smooth muscle actin (α-SMA)-positive myofibroblasts. A similar shift occurs during myofibroblast differentiation in culture and seems to be responsible for the homotypic segregation of α-SMA-positive and -negative fibroblasts in suspension. AJs of plated myofibroblasts are reinforced by α-SMA–mediated contractile activity, resulting in high mechanical resistance as demonstrated by subjecting cell pairs to hydrodynamic forces in a flow chamber. A peptide that inhibits α-SMA–mediated contractile force causes the reorganization of large stripe-like AJs to belt-like contacts as shown for enhanced green fluorescent protein-α–catenin-transfected cells and is associated with a reduced mechanical resistance. Anti-OB-cadherin but not anti-N-cadherin peptides reduce the contraction of myofibroblast-populated collagen gels, suggesting that AJs are instrumental for myofibroblast contractile activity.

scholarly journals Live-Cell Analysis of a Green Fluorescent Protein-Tagged Herpes Simplex Virus Infection

1999 ◽  
Vol 73 (5) ◽  
pp. 4110-4119 ◽  
Author(s):  
Gillian Elliott ◽  
Peter O’Hare
Keyword(s):  
Herpes Simplex Virus ◽  
Green Fluorescent Protein ◽  
Herpes Simplex ◽  
Fluorescent Protein ◽  
Time Lapse ◽  
Live Cell ◽  
Cell Periphery ◽  
Green Fluorescent ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACT Many stages of the herpes simplex virus maturation pathway have not yet been defined. In particular, little is known about the assembly of the virion tegument compartment and its subsequent incorporation into maturing virus particles. Here we describe the construction of a herpes simplex virus type 1 (HSV-1) recombinant in which we have replaced the gene encoding a major tegument protein, VP22, with a gene expressing a green fluorescent protein (GFP)-VP22 fusion protein (GFP-22). We show that this virus has growth properties identical to those of the parental virus and that newly synthesized GFP-22 is detectable in live cells as early as 3 h postinfection. Moreover, we show that GFP-22 is incorporated into the HSV-1 virion as efficiently as VP22, resulting in particles which are visible by fluorescence microscopy. Consequently, we have used time lapse confocal microscopy to monitor GFP-22 in live-cell infection, and we present time lapse animations of GFP-22 localization throughout the virus life cycle. These animations demonstrate that GFP-22 is present in a diffuse cytoplasmic location when it is initially expressed but evolves into particulate material which travels through an exclusively cytoplasmic pathway to the cell periphery. In this way, we have for the first time visualized the trafficking of a herpesvirus structural component within live, infected cells.

scholarly journals Complexes between Herpes Simplex Virus Glycoproteins gD, gB, and gH Detected in Cells by Complementation of Split Enhanced Green Fluorescent Protein

2007 ◽  
Vol 81 (20) ◽  
pp. 11532-11537 ◽  
Author(s):  
Elisa Avitabile ◽  
Cristina Forghieri ◽  
Gabriella Campadelli-Fiume
Keyword(s):  
Herpes Simplex Virus ◽  
Green Fluorescent Protein ◽  
Herpes Simplex ◽  
Enhanced Green Fluorescent Protein ◽  
Fluorescent Protein ◽  
Split Egfp ◽  
Green Fluorescent ◽  
Simplex Virus ◽  
In Cells

ABSTRACT The interactions between herpes simplex virus gD and its nectin1 receptor or between gD, gB, and gH were analyzed by complementation of the N and C portions of split enhanced green fluorescent protein (EGFP) fused to the glycoproteins. The gDN-NectC complex was readily detected; the gDN-gCC complex was undetectable, highlighting the specificity of the assay. Split EGFP complementation was detected between proteins designated gDN+gHC, gDN+gBC, and gHN+gBC+wtgD (gB was deleted of endocytosis motifs), both in cells transfected with two-tree glycoproteins and in syncytia. The in situ assay provides evidence that gD interacts with gH and gB independently of each other and supports a model whereby gH and gB in complex exert their activities to gD.

scholarly journals Temporal cAMP Signaling Selectivity by Natural and Synthetic MC4R Agonists

2015 ◽  
Vol 29 (11) ◽  
pp. 1619-1633 ◽  
Author(s):  
Brent M. Molden ◽  
Kimberly A. Cooney ◽  
Kirk West ◽  
Lex H. T. Van Der Ploeg ◽  
Giulia Baldini
Keyword(s):  
Fluorescent Protein ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Camp Signaling ◽  
Intracellular Camp ◽  
Specific Cell ◽  
Melanocortin 4 Receptor ◽  
Green Fluorescent ◽  
Camp Induction ◽  
Agouti Related Protein

Abstract The melanocortin-4 receptor (MC4R) is a G protein-coupled receptor expressed in the brain, where it controls energy balance through pathways including α-melanocyte-stimulating hormone (α-MSH)-dependent signaling. We have reported that the MC4R can exist in an active conformation that signals constitutively by increasing cAMP levels in the absence of receptor desensitization. We asked whether synthetic MC4R agonists differ in their ability to increase intracellular cAMP over time in Neuro2A cells expressing endogenous MC4R and exogenous, epitope-tagged hemagglutinin-MC4R-green fluorescent protein. By analyzing intracellular cAMP in a temporally resolved Förster resonance energy transfer assay, we show that withdrawal of α-MSH leads to a quick reversal of cAMP induction. By contrast, the synthetic agonist melanotan II (MTII) induces a cAMP signal that persists for at least 1 hour after removal of MTII from the medium and cannot be antagonized by agouti related protein. Similarly, in mHypoE-42 immortalized hypothalamic neurons, MTII, but not α-MSH, induced persistent AMP kinase signal, which occurs downstream of increased cAMP. By using a fluorescence recovery after photobleaching assay, it appears that the receptor exposed to MTII continues to signal after being internalized. Similar to MTII, the synthetic MC4R agonists, THIQ and BIM-22511, but not LY2112688, induced prolonged cAMP signaling after agonist withdrawal. However, agonist-exposed MC4R desensitized to the same extent, regardless of the ligand used and regardless of differences in receptor intracellular retention kinetics. In conclusion, α-MSH and LY2112688, when compared with MTII, THIQ, and BIM-22511, vary in the duration of the acute cAMP response, showing distinct temporal signaling selectivity, possibly linked to specific cell compartments from which cAMP signals may originate.

scholarly journals Relaxed Repression of Herpes Simplex Virus Type 1 Genomes in Murine Trigeminal Neurons

2007 ◽  
Vol 81 (22) ◽  
pp. 12394-12405 ◽  
Author(s):  
Tracy Terry-Allison ◽  
Colton A. Smith ◽  
Neal A. DeLuca
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Fluorescent Protein ◽  
Cultured Cells ◽  
Trichostatin A ◽  
Cell Types ◽  
Immediate Early ◽  
Green Fluorescent ◽  
Simplex Virus

ABSTRACT The expression of herpes simplex virus (HSV) genomes in the absence of viral regulatory proteins in sensory neurons is poorly understood. Previously, our group reported an HSV immediate early (IE) mutant (d109) unable to express any of the five IE genes and encoding a model human cytomegalovirus immediate early promoter-green fluorescent protein (GFP) transgene. In cultured cells, GFP expressed from this mutant was observed in only a subset of infected cells. The subset exhibited cell type dependence, as the fractions of GFP-expressing cells varied widely among the cell types examined. Herein, we characterize this mutant in murine embryonic trigeminal ganglion (TG) cultures. We found that d109 was nontoxic to neural cultures and persisted in the cultures throughout their life spans. Unlike with some of the cultured cell lines and strains, expression of the GFP transgene was observed in a surprisingly large subset of neurons. However, very few nonneuronal cells expressed GFP. The abilities of ICP0 and an inhibitor of histone deacetylase, trichostatin A (TSA), to activate GFP expression from nonexpressing cells were also compared. The provision of ICP0 by infection with d105 reactivated quiescent genomes in nearly every cell, whereas reactivation by TSA was much more limited and restricted to the previously nonexpressing neurons. Moreover, we found that d109, which does not express ICP0, consistently reactivated HSV type 1 (KOS) in latently infected adult TG cultures. These results suggest that the state of persisting HSV genomes in some TG neurons may be more dynamic and more easily activated than has been observed with nonneuronal cells.

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