scholarly journals Ependymoma associated protein Zfta is expressed in immature ependymal cells but is not essential for ependymal development in mice

2021 ◽  
Author(s):  
Vicente Herranz-Pérez ◽  
Jin Nakatani ◽  
Masaki Ishii ◽  
Toshiaki Katada ◽  
Jose Manuel García-Verdugo ◽  
...  
Keyword(s):  
Cultured Cells ◽  
Luciferase Activity ◽  
Ependymal Cells ◽  
Upstream Sequence ◽  
Embryonic Brain ◽  
Developmental Defects ◽  
Ciliary Beating ◽  
Supratentorial Ependymoma ◽  
Beating Frequency ◽  
Lateral Walls

Abstract The fusion protein of uncharacterised zinc finger translocation associated (ZFTA) and effector transcription factor of tumorigenic NF-kB signalling, RELA (ZFTA-RELA), is expressed in more than two-thirds of supratentorial ependymoma (ST-EPN-RELA), but ZFTA’s expression profile and functional analysis in multiciliated ependymal (E1) cells have not been examined. Here, we showed the mRNA expression of mouse Zfta peaks on embryonic day (E) 17.5 in the wholemount of the lateral walls of the lateral ventricle. Zfta was expressed in the nuclei of FoxJ1-positive immature E1 (pre-E1) cells in E18.5 mouse embryonic brain. Interestingly, the transcription factors promoting ciliogenesis (ciliary TFs) (e.g., multicilin) and ZFTA-RELA upregulated luciferase activity using a 5’ upstream sequence of ZFTA in cultured cells. Zftatm1/tm1 knock-in mice did not show developmental defects or abnormal fertility. In the Zftatm1/tm1 E1 cells, morphology, gene expression, ciliary beating frequency and ependymal flow were unaffected. These results suggest that Zfta is expressed in pre-E1 cells, possibly under the control of ciliary TFs, but is not essential for ependymal development or flow. This study sheds light on the mechanism of the ZFTA-RELA expression in the pathogenesis of ST-EPN-RELA: Ciliary TFs initiate ZFTA-RELA expression in pre-E1 cells, and ZFTA-RELA enhances its own expression using positive feedback.

Spectral characterization of ciliary beating: variations of frequency with time

1985 ◽  
Vol 249 (1) ◽  
pp. C160-C165 ◽  
Author(s):  
D. Eshel ◽  
Y. Grossman ◽  
Z. Priel
Keyword(s):  
Mathematical Model ◽  
Power Spectra ◽  
Ciliary Beating ◽  
Isolated Lung ◽  
Ciliary Cell ◽  
The Mathematical Model ◽  
Beating Frequency ◽  
Over Time ◽  
Dominant Frequencies

Ciliary beating frequency in tissue culture from frog palate and isolated lung was optically examined using instrumentation that was adjusted to measure a fraction of the surface area of a single ciliary cell. Consecutive 1-s segments of the analogue signal were fast Fourier transformed (FFT) to obtain a power spectrum. At room temperature, these power spectra changed over time from 1 s to the next. Each spectrum contained several dominant frequencies of similar intensities. Cooling the preparation resulted in a single-peak spectrum that was constant over time. A mathematical model is proposed to simulate these findings. The results and the mathematical model support the hypothesis that ciliary beating frequency fluctuates over short periods of time.

scholarly journals Intracellular pathways regulating ciliary beating of rat brain ependymal cells

2001 ◽  
Vol 531 (1) ◽  
pp. 131-140 ◽  
Author(s):  
Thien Nguyen ◽  
Wei‐Chun Chin ◽  
Jennifer A. O'Brien ◽  
Pedro Verdugo ◽  
Albert J. Berger
Keyword(s):  
Rat Brain ◽  
Ependymal Cells ◽  
Ciliary Beating ◽  
Intracellular Pathways

Effect of pH, Viscosity and Ionic-Strength Changes on Ciliary Beating Frequency of Human Bronchial Explants

1983 ◽  
Vol 64 (4) ◽  
pp. 449-451 ◽  
Author(s):  
Chun Ka Luk ◽  
Mauricio J. Dulfano
Keyword(s):  
Ionic Strength ◽  
Marked Reduction ◽  
Beat Frequency ◽  
Ciliary Beat Frequency ◽  
Ciliary Activity ◽  
Rapid Loss ◽  
Significant Drop ◽  
Ciliary Beating ◽  
Beating Frequency

1. Ciliary activity is significantly influenced by chemical and physical properties of the liquid medium in which the cilia beat. 2. We studied the effect of changes in pH, ionic strength and viscosity on the ciliary beat frequency (CBF) of explants of human respiratory mucosa. 3. Optimal CBF was elicited at pH 7.0-9.0, with a marked reduction of CBF outside these limits. The CBF was well preserved at NaCl concentrations between 5 g/l (80 mmol/l) and 12 g/l (200 mmol/l), but there was rapid loss at concentrations below 0.5 gA (10 mmol/l). The cilia beat best at viscosities below 1.0 centipoises (1 mN s m−2). Increase of the viscosity gradually decreases CBF with a significant drop at viscosities above 87 millipoises. 4. It is concluded that the above limits may fairly accurately indicate the actual physical characteristics of the periciliary environment (‘sol layer’) in vivo.

scholarly journals Groucho Oligomerization Is Required for Repression In Vivo

2004 ◽  
Vol 24 (10) ◽  
pp. 4341-4350 ◽  
Author(s):  
Haiyun Song ◽  
Peleg Hasson ◽  
Ze’ev Paroush ◽  
Albert J. Courey
Keyword(s):  
Target Genes ◽  
Cultured Cells ◽  
Coiled Coil ◽  
S2 Cells ◽  
Wild Type ◽  
Developmental Defects ◽  
Conserved Domain ◽  
Wing Disk ◽  
Single Motif

ABSTRACT Drosophila Groucho (Gro) is a member of a family of metazoan corepressors with widespread roles in development. Previous studies indicated that a conserved domain in Gro, termed the Q domain, was required for repression in cultured cells and mediated homotetramerization. Evidence presented here suggests that the Q domain contains two coiled-coil motifs required for oligomerization and repression in vivo. Mutagenesis of the putative hydrophobic faces of these motifs, but not of the hydrophilic faces, prevents the formation of both tetramers and higher order oligomers. Mutagenesis of the hydrophobic faces of both coiled-coil motifs in the context of a Gal4-Gro fusion protein prevents repression of a Gal4-responsive reporter in S2 cells, while mutagenesis of a single motif weakens repression. The finding that the repression directed by the single mutants depends on endogenous wild-type Gro further supports the idea that oligomerization plays a role in repression. Overexpression in the fly of forms of Gro able to oligomerize, but not of a form of Gro unable to oligomerize, results in developmental defects and ectopic repression of Gro target genes in the wing disk. Although the function of several corepressors is suspected to involve oligomerization, these studies represent one of the first direct links between corepressor oligomerization and repression in vivo.

scholarly journals Ectopic Expression of SPARC in Xenopus Embryos Interferes with Tissue Morphogenesis: Identification of a Bioactive Sequence in the C-terminal EF Hand

1997 ◽  
Vol 45 (5) ◽  
pp. 643-655 ◽  
Author(s):  
Sashko Damjanovski ◽  
Xantha Karp ◽  
Sarah Funk ◽  
E. Helene Sage ◽  
Maurice J. Ringuette
Keyword(s):  
Cultured Cells ◽  
Ectopic Expression ◽  
Copper Binding ◽  
Tissue Morphogenesis ◽  
Obvious Effect ◽  
Developmental Defects ◽  
Xenopus Embryos ◽  
Axial Defects

SPARC is a matricellular Ca2+-binding glycoprotein that exhibits both counteradhesive and antiproliferative effects on cultured cells. It is secreted by cells of various tissues as a consequence of morphogenesis, response to injury, and cyclic renewal and/or repair. In an earlier study with Xenopus embryos we had shown a highly specific and regulated pattern of SPARC expression. We now show that ectopic expression of SPARC before its normal embryonic activation produces severe anomalies, some of which are consistent with the functions of SPARC proposed from studies in vitro. Microinjection of SPARC RNA, protein, and peptides into Xenopus embryos before endogenous embryonic expression generated different but overlapping phenotypes. (a) Injection of SPARC RNA into one cell of a two-cell embryo resulted in a range of unilateral defects. (b) Precocious exposure of embryos to SPARC by microinjection of protein into the blastocoel cavity was associated with certain axial defects comparable to those obtained with SPARC RNA. (c) SPARC peptides containing follistatin-like and copper-binding sequences were without obvious effect, whereas SPARC peptide 4.2, corresponding to a disulfide-bonded, Ca2+-binding domain, was associated with a reduction in axial structures that led eventually to complete ventralization of the embryos. Histological analysis of ventralized embryos indicated that the morphogenetic events associated with gastrulation might have been inhibited. Microinjection of other Ca2+-binding glycoproteins, such as osteopontin and bone sialoprotein, resulted in phenotypes that were unique. We probed further the structural correlates of this region of SPARC in the context of tissue development. Co-injection of peptide 4.2 with Ca2+ or EGTA, and injection of peptide 4.2K (containing a mutated consensus Ca2+-binding sequence), demonstrated that the developmental defects associated with peptide 4.2 were independent of Ca2+. However, the disulfide bridge in this region of SPARC was found to be critical, as injection of peptide 4.2AA, a mutant lacking the cystine, generated no axial defects. We have therefore shown for the first time in vivo that the temporally inappropriate presence of SPARC is associated with perturbations in tissue morphogenesis. Moreover, we have identified at least one bioactive region of SPARC as the C-terminal disulfide-bonded, Ca2+-binding loop that was previously shown to be both counteradhesive and growth-inhibitory.

Analysis of ciliary beating frequency under voltage clamp control of the membrane

Cell Motility ◽  
1982 ◽  
Vol 2 (S1) ◽  
pp. 205-210 ◽  
Author(s):  
Hans Machemer ◽  
Jacques E. de Peyer
Keyword(s):  
Voltage Clamp ◽  
Ciliary Beating ◽  
Beating Frequency
Sign in / Sign up

Export Citation Format

Share Document