scholarly journals Excess Glutamate May Cause Dilation of Retinal Blood Vessels in Glutamate/Aspartate Transporter-Deficient Mice

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Takayuki Gonome ◽  
Yuting Xie ◽  
Saeko Arai ◽  
Kodai Yamauchi ◽  
Natsuki Maeda-Monai ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Outer Nuclear Layer ◽  
Mouse Retina ◽  
Ganglion Cell Complex ◽  
Wild Type ◽  
Time Points ◽  
Retinal Blood Vessels ◽  
In The Wild ◽  
First Time ◽  
Sd Oct

Purpose. To investigate the longitudinal findings of fundus features and spectral-domain optical coherence tomography (SD-OCT) to characterize the morphologic features in a mouse model of defective glutamate/aspartate transporter (GLAST−/− mice). Materials and Methods. The fundus findings and SD-OCT images were longitudinally recorded at five time points from postnatal (P) 22 to P156 in GLAST−/− mice. As a control wild type, age-matched C57BL/6J mice were employed. The mouse retina was subdivided into five layers, and the thickness of each layer was longitudinally measured by InSight® using SD-OCT pictures. The SD-OCT findings were compared with the histologic appearances. The diameter of the retinal blood vessels was measured by the ImageJ® software program using SD-OCT images. The data were statistically compared between both age-matched mouse groups. Results. The retinal blood vessels appeared more dilated in GLAST−/− mice than in wild-type mice. This tendency was statistically significant at all time points after P44 by analyses using SD-OCT images. The ganglion cell complex (GCC) and outer nuclear layer (ONL) were significantly thinner in GLAST−/− mice at all time points after P80 than in the wild-type mice. This tendency was more clearly indicated by SD-OCT than histologic sections. Discussion. In the present study, we found for the first time the dilation of the retinal blood vessels and the thinning of the ONL in GLAST−/− mice, in addition to the thinning of the GCC.

scholarly journals Role of Acinetobacter baylyi Crc in Catabolite Repression of Enzymes for Aromatic Compound Catabolism

2009 ◽  
Vol 191 (8) ◽  
pp. 2834-2842 ◽  
Author(s):  
Tina Zimmermann ◽  
Tobias Sorg ◽  
Simone Yasmin Siehler ◽  
Ulrike Gerischer
Keyword(s):  
Catabolite Repression ◽  
Carbon Sources ◽  
Transcript Abundance ◽  
Growth Conditions ◽  
Wild Type ◽  
Acinetobacter Baylyi ◽  
Transcript Stability ◽  
Key Enzyme ◽  
In The Wild ◽  
First Time

ABSTRACT Here, we describe for the first time the Crc (catabolite repression control) protein from the soil bacterium Acinetobacter baylyi. Expression of A. baylyi crc varied according to the growth conditions. A strain with a disrupted crc gene showed the same growth as the wild type on a number of carbon sources. Carbon catabolite repression by acetate and succinate of protocatechuate 3,4-dioxygenase, the key enzyme of protocatechuate breakdown, was strongly reduced in the crc strain, whereas in the wild-type strain it underwent strong catabolite repression. This strong effect was not based on transcriptional regulation because the transcription pattern of the pca-qui operon (encoding protocatechuate 3,4-dioxygenase) did not reflect the derepression in the absence of Crc. pca-qui transcript abundance was slightly increased in the crc strain. Lack of Crc dramatically increased the mRNA stability of the pca-qui transcript (up to 14-fold), whereas two other transcripts (pobA and catA) remained unaffected. p-Hydroxybenzoate hydroxylase activity, encoded by pobA, was not significantly different in the absence of Crc, as protocatechuate 3,4-dioxygenase was. It is proposed that A. baylyi Crc is involved in the determination of the transcript stability of the pca-qui operon and thereby effects catabolite repression.

scholarly journals Correlations between ERG, OCT, and Anatomical Findings in therd10Mouse

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Sarah Rösch ◽  
Sandra Johnen ◽  
Frank Müller ◽  
Christiane Pfarrer ◽  
Peter Walter
Keyword(s):  
Optical Coherence Tomography ◽  
Light Intensity ◽  
Outer Nuclear Layer ◽  
Age Group ◽  
Wild Type ◽  
Full Field ◽  
Histological Staining ◽  
Microscopic Findings ◽  
Sd Oct

Background. To evaluate the correlation between ERG, OCT, and microscopic findings in therd10mouse.Methods. C57BL/6J wild type mice andrd10mice were compared at the age of 2, 3, 5, 7, 9, 12, 24, and 48 weeks (each age groupn=3) using full-field electroretinography (ERG), spectral domain Optical Coherence Tomography (sd-OCT), fluorescein angiography (FA), Hematoxylin & Eosin histology (HE), and immunohistology (IH).Results. While in wild type mice, the amplitude of a- and b-wave increased with light intensity and with the age of the animals, therd10mice showed extinction of the ERG beginning with the age of 5 weeks. In OCT recordings, the thickness of the retina decreased up to 9 weeks of age, mainly based on the degradation of the outer nuclear layer (ONL). Afterwards, the ONL was no longer visible in the OCT. HE staining and immunohistological findings confirmed thein vivodata.Conclusion. ERG and OCT are useful methods to evaluate the retinal function and structurein vivo. The retinal changes seen in the OCT closely match those observed in histological staining.

scholarly journals Comparison of phase-resolved Doppler optical coherence tomography and optical coherence tomography angiography for measuring retinal blood vessels size

2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Zohreh Hosseinaee ◽  
Bingyao Tan ◽  
Kostadinka Bizheva
Keyword(s):  
Optical Coherence Tomography ◽  
Blood Vessels ◽  
Optical Coherence ◽  
Acquisition Rate ◽  
Doppler Oct ◽  
Retinal Blood Vessels ◽  
Significant Difference ◽  
Arteries And Veins ◽  
System Operating ◽  
Sd Oct

The goal of this study was to compare two OCT-based methods for measuring retinal blood vessels size: Phase-resolved Doppler OCT (DOCT) and OCT angiography (OCTA). The study was conducted in rats (n= 6) using a SD-OCT system operating at 1060 nm with 92 kHz image acquisition rate. Arteries and veins were separated by the phase polarity. Results from this study showed that the venal diameters are significantly larger than the arterial diameters, and there is no significant difference in the vessel diameters measured by both methods.

scholarly journals Targeted Disruption of Outer Limiting Membrane Junctional Proteins (Crb1 and ZO-1) Increases Integration of Transplanted Photoreceptor Precursors into the Adult Wild-Type and Degenerating Retina

2010 ◽  
Vol 19 (4) ◽  
pp. 487-503 ◽  
Author(s):  
R. A. Pearson ◽  
A. C. Barber ◽  
E. L. West ◽  
R. E. Maclaren ◽  
Y. Duran ◽  
...  
Keyword(s):  
Retinitis Pigmentosa ◽  
Adherens Junctions ◽  
Outer Nuclear Layer ◽  
Donor Cell ◽  
Adaptor Proteins ◽  
Wild Type ◽  
Targeted Disruption ◽  
Stage Of Development ◽  
Junctional Proteins ◽  
In The Wild

Diseases culminating in photoreceptor loss are a major cause of untreatable blindness. Transplantation of rod photoreceptors is feasible, provided donor cells are at an appropriate stage of development when transplanted. Nevertheless, the proportion of cells that integrate into the recipient outer nuclear layer (ONL) is low. The outer limiting membrane (OLM), formed by adherens junctions between Müller glia and photoreceptors, may impede transplanted cells from migrating into the recipient ONL. Adaptor proteins such as Crumbs homologue 1 (Crb1) and zona occludins (ZO-1) are essential for localization of the OLM adherens junctions. We investigated whether targeted disruption of these proteins enhances donor cell integration. Transplantation of rod precursors in wild-type mice achieved 949 ± 141 integrated cells. By contrast, integration is significantly higher when rod precursors are transplanted into Crb1rd8/rd8 mice, a model of retinitis pigmentosa and Lebers congenital amaurosis that lacks functional CRB1 protein and displays disruption of the OLM (7,819 ± 1,297; maximum 15,721 cells). We next used small interfering (si)RNA to transiently reduce the expression of ZO-1 and generate a reversible disruption of the OLM. ZO-1 knockdown resulted in similar, significantly improved, integration of transplanted cells in wild-type mice (7,037 ± 1,293; maximum 11,965 cells). Finally, as the OLM remains largely intact in many retinal disorders, we tested whether transient ZO-1 knockdown increased integration in a model of retinitis pigmentosa, the rho-/- mouse; donor cell integration was significantly increased from 313 ± 58 cells without treatment to 919 ± 198 cells after ZO-1 knockdown. This study shows that targeted disruption of OLM junctional proteins enhances integration in the wild-type and degenerating retina and may be a useful approach for developing photoreceptor transplantation strategies.

scholarly journals Plasticity of TRPM1 expression and localization in the wild type and degenerating mouse retina

2010 ◽  
Vol 50 (23) ◽  
pp. 2460-2465 ◽  
Author(s):  
David Križaj ◽  
Wei Huang ◽  
Takahisa Furukawa ◽  
Claudio Punzo ◽  
Wei Xing
Keyword(s):  
Mouse Retina ◽  
Wild Type ◽  
In The Wild

scholarly journals Discovery of an Unusual Fatty Acid Amide from the ndgRyo Gene Mutant of Marine-Derived Streptomyces youssoufiensis

Marine Drugs ◽  
2018 ◽  
Vol 17 (1) ◽  
pp. 12
Author(s):  
Jing Hou ◽  
Jing Liu ◽  
Lu Yang ◽  
Zengzhi Liu ◽  
Huayue Li ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Target Gene ◽  
Acid Amide ◽  
Wild Type ◽  
Spectroscopic Analyses ◽  
Gene Mutant ◽  
Mutant Strains ◽  
In The Wild ◽  
First Time ◽  
Fatty Acid Amide

NdgRyo, an IclR-like regulator, was selected as the target gene to activate new secondary metabolites in the marine-derived Streptomyces youssoufiensis OUC6819. Inactivation of the ndgRyo gene in S. youssoufiensis OUC6819 led to the accumulation of a new fatty acid amide (1), with an unusual 3-amino-butyl acid as the amine component. Moreover, its parent fatty acid (2) was also discovered both in the wild-type and ΔndgRyo mutant strains, which was for the first time isolated from a natural source. The structures of compounds 1 and 2 were elucidated by combination of LC-MS and NMR spectroscopic analyses. This study demonstrated that the ndgRyo homologs might serve as a target for new compound activation in Streptomyces strains.

scholarly journals RNAi-mediated gene knockdown of progesterone 5β-reductases in Digitalis lanata reduces 5β-cardenolide content

2021 ◽  
Author(s):  
Jan Klein ◽  
Elisa Horn ◽  
Mona Ernst ◽  
Tim Leykauf ◽  
Tamara Leupold ◽  
...  
Keyword(s):  
Experimental Evidence ◽  
Direct Evidence ◽  
Shoot Culture ◽  
Buthionine Sulfoximine ◽  
Wild Type ◽  
Crucial Step ◽  
Methyl Vinyl ◽  
Digitalis Lanata ◽  
In The Wild ◽  
First Time

Abstract Key message Studying RNAi-mediated DlP5βR1 and DlP5βR2 knockdown shoot culture lines of Digitalis lanata, we here provide direct evidence for the participation of PRISEs (progesterone 5β-reductase/iridoid synthase-like enzymes) in 5β-cardenolide formation. Abstract Progesterone 5β-reductases (P5βR) are assumed to catalyze the reduction of progesterone to 5β-pregnane-3,20-dione, which is a crucial step in the biosynthesis of the 5β-cardenolides. P5βRs are encoded by VEP1-like genes occurring ubiquitously in embryophytes. P5βRs are substrate-promiscuous enone-1,4-reductases recently termed PRISEs (progesterone 5β-reductase/iridoid synthase-like enzymes). Two PRISE genes, termed DlP5βR1 (AY585867.1) and DlP5βR2 (HM210089.1) were isolated from Digitalis lanata. To give experimental evidence for the participation of PRISEs in 5β-cardenolide formation, we here established several RNAi-mediated DlP5βR1 and DlP5βR2 knockdown shoot culture lines of D. lanata. Cardenolide contents were lower in D. lanata P5βR-RNAi lines than in wild-type shoots. We considered that the gene knockdowns may have had pleiotropic effects such as an increase in glutathione (GSH) which is known to inhibit cardenolide formation. GSH levels and expression of glutathione reductase (GR) were measured. Both were higher in the Dl P5βR-RNAi lines than in the wild-type shoots. Cardenolide biosynthesis was restored by buthionine sulfoximine (BSO) treatment in Dl P5βR2-RNAi lines but not in Dl P5βR1-RNAi lines. Since progesterone is a precursor of cardenolides but can also act as a reactive electrophile species (RES), we here discriminated between these by comparing the effects of progesterone and methyl vinyl ketone, a small RES but not a precursor of cardenolides. To the best of our knowledge, we here demonstrated for the first time that P5βR1 is involved in cardenolide formation. We also provide further evidence that PRISEs are also important for plants dealing with stress by detoxifying reactive electrophile species (RES).

The pigmentary system of developing axolotls

Development ◽  
1986 ◽  
Vol 92 (1) ◽  
pp. 255-268
Author(s):  
S. K. Frost ◽  
L. G. Epp ◽  
S. J. Robinson
Keyword(s):  
Developmental Stages ◽  
Structural Characteristics ◽  
Cell Types ◽  
Ambystoma Mexicanum ◽  
Pigment Cells ◽  
Wild Type ◽  
Transmission Electron ◽  
In The Wild ◽  
Yellow Pigments ◽  
First Time

The albino mutant in the Mexican axolotl (Ambystoma mexicanum) is analysed with respect to the differentiation of pigment cells. Pigment cells were observed with the transmission electron microscope in order to determine any unusual structural characteristics and to determine what happens to each of the cell types as development proceeds. Chemical analyses of pteridine pigments were also carried out, and the pattern of pteridines in albino animals was found to be more complex than, and quantitatively enhanced (at all developmental stages examined) over, the pattern observed in comparable wild-type axolotls. The golden colour of albino axolotls is due primarily to sepiapterin (a yellow pteridine) and secondarily to riboflavin (and other flavins). Coincident with enhanced levels of yellow pigments, xanthophore pigment organelles (pterinosomes) in albino skin reach a mature state earlier than they do in wild-type axolotl skin. This morphology is conserved throughout development in albino animals whereas it is gradually lost in the wild type. Unpigmented melanophores from albino axolotls are illustrated for the first time, and in larval albino axolotls the morphology of these cells is shown to be very similar to xanthophore morphology. In older albino animals xanthophores are easily distinguished from unpigmented melanophores. Iridophores seem to appear in albino skin at an earlier stage than they have been observed in wild-type skin. Morphologically, wild-type and albino iridophores are identical.

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