scholarly journals Fluorescent detection of PARP activity in unfixed tissue

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245369
Author(s):  
Soumaya Belhadj ◽  
Andreas Rentsch ◽  
Frank Schwede ◽  
François Paquet-Durand
Keyword(s):  
Retinal Degeneration ◽  
Specific Inhibitor ◽  
Photoreceptor Cells ◽  
Fluorescent Detection ◽  
Activity Assay ◽  
Dna Breaks ◽  
Enzyme Activity Assay ◽  
Specific Signal ◽  
Parp Activity

Poly-ADP-ribose-polymerase (PARP) relates to a family of enzymes that can detect DNA breaks and initiate DNA repair. While this activity is generally seen as promoting cell survival, PARP enzymes are also known to be involved in cell death in numerous pathologies, including in inherited retinal degeneration. This ambiguous role of PARP makes it attractive to have a simple and fast enzyme activity assay, that allows resolving its enzymatic activity in situ, in individual cells, within complex tissues. A previously published two-step PARP activity assay uses biotinylated NAD+ and streptavidin labelling for this purpose. Here, we used the fluorescent NAD+ analogues ε-NAD+ and 6-Fluo-10-NAD+ to assess PARP activity directly on unfixed tissue sections obtained from wild-type and retinal degeneration-1 (rd1) mutant retina. In standard UV microscopy ε-NAD+ incubation did not reveal PARP specific signal. In contrast, 6-Fluo-10-NAD+ resulted in reliable detection of in situ PARP activity in rd1 retina, especially in the degenerating photoreceptor cells. When the 6-Fluo-10-NAD+ based PARP activity assay was performed in the presence of the PARP specific inhibitor olaparib, the activity signal was completely abolished, attesting to the specificity of the assay. The incubation of live organotypic retinal explant cultures with 6-Fluo-10-NAD+, did not produce PARP specific signal, indicating that the fluorescent marker may not be sufficiently membrane-permeable to label living cells. In summary, we present a new, rapid, and simple to use fluorescence assay for the cellular resolution of PARP activity on unfixed tissue, for instance in complex neuronal tissues such as the retina.

Expression and Enzyme Activity Assay of pfu with Molecular Chaperone

2010 ◽  
Vol 31 (6) ◽  
pp. 499-503
Author(s):  
Hai-Jun ZHANG ◽  
Jun YANG ◽  
Xiao-Guang LIU ◽  
Xiang-Yang HU
Keyword(s):  
Enzyme Activity ◽  
Molecular Chaperone ◽  
Activity Assay ◽  
Enzyme Activity Assay

scholarly journals Nutraceutical Supplementation Ameliorates Visual Function, Retinal Degeneration, and Redox Status in rd10 Mice

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1033
Author(s):  
Lorena Olivares-González ◽  
Sheyla Velasco ◽  
Isabel Campillo ◽  
David Salom ◽  
Emilio González-García ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Retinal Degeneration ◽  
Antioxidant Properties ◽  
Photoreceptor Cells ◽  
Redox Status ◽  
Inherited Retinal Dystrophies ◽  
Stress Markers ◽  
Retinal Dystrophies ◽  
Progressive Degeneration ◽  
Light Stimuli

Background: Retinitis pigmentosa (RP) is a group of inherited retinal dystrophies characterized by progressive degeneration of photoreceptor cells. Ocular redox status is altered in RP suggesting oxidative stress could contribute to their progression. In this study, we investigated the effect of a mixture of nutraceuticals with antioxidant properties (NUT) on retinal degeneration in rd10 mice, a model of RP. Methods: NUT was orally administered to rd10 mice from postnatal day (PD) 9 to PD18. At PD18 retinal function and morphology were examined by electroretinography (ERG) and histology including TUNEL assay, immunolabeling of microglia, Müller cells, and poly ADP ribose polymers. Retinal redox status was determined by measuring the activity of antioxidant enzymes and some oxidative stress markers. Gene expression of the cytokines IL-6, TNFα, and IL-1β was assessed by real-time PCR. Results: NUT treatment delayed the loss of photoreceptors in rd10 mice partially preserving their electrical responses to light stimuli. Moreover, it ameliorated redox status and reduced inflammation including microglia activation, upregulation of cytokines, reactive gliosis, and PARP overactivation. Conclusions: NUT ameliorated retinal functionality and morphology at early stages of RP in rd10 mice. This formulation could be useful as a neuroprotective approach for patients with RP in the future.

scholarly journals A new method to detect apoptosis in paraffin sections: in situ end-labeling of fragmented DNA.

1993 ◽  
Vol 41 (1) ◽  
pp. 7-12 ◽  
Author(s):  
J H Wijsman ◽  
R R Jonker ◽  
R Keijzer ◽  
C J van de Velde ◽  
C J Cornelisse ◽  
...  
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Staining Method ◽  
Morphological Characteristics ◽  
Image Cytometry ◽  
Apoptotic Cells ◽  
Dna Breaks ◽  
Paraffin Sections ◽  
Tissue Sections

Apoptosis (programmed cell death) can be difficult to detect in routine histological sections. Since extensive DNA fragmentation is an important characteristic of this process, visualization of DNA breaks could greatly facilitate the identification of apoptotic cells. We describe a new staining method for formalin-fixed, paraffin-embedded tissue sections that involves an in situ end-labeling (ISEL) procedure. After protease treatment to permeate the tissue sections, biotinylated nucleotides are in situ incorporated into DNA breaks by polymerase and subsequently stained with DAB via peroxidase-conjugated avidin. Staining of cells with the morphological characteristics of apoptosis was demonstrated in tissues known to exhibit programmed cell death, i.e., prostate and uterus after castration, tumors, lymph node follicles, and embryos. Apoptotic cells could be discriminated morphologically from areas of labeled necrotic cells, in which DNA degradation also occurs. Because apoptosis is relatively easily recognized in H&E-stained sections of involuting prostates of castrated rats, we used this model system to validate the ISEL method for the quantification of apoptotic cells. A high correlation was found between the fractions of ISEL-labeled cells and the fractions of apoptotic cells that were morphologically determined in adjacent sections. We conclude that ISEL is a useful technique for quantification of apoptosis in paraffin sections, especially for those tissues in which morphological determination is difficult. Furthermore, this new staining method enables the use of automated image cytometry for evaluating apoptosis.

scholarly journals The rhodopsin-retinochrome system for retinal re-isomerization predates the origin of cephalopod eyes

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Oliver Vöcking ◽  
Lucas Leclère ◽  
Harald Hausen
Keyword(s):  
In Situ Hybridization ◽  
Photoreceptor Cells ◽  
Visual Cycle ◽  
Phylogenetic Distribution ◽  
Enzymatic Process ◽  
Antibody Staining ◽  
The Individual ◽  
Functional Components ◽  
Visual Rhodopsin

Abstract Background The process of photoreception in most animals depends on the light induced isomerization of the chromophore retinal, bound to rhodopsin. To re-use retinal, the all-trans-retinal form needs to be re-isomerized to 11-cis-retinal, which can be achieved in different ways. In vertebrates, this mostly includes a stepwise enzymatic process called the visual cycle. The best studied re-isomerization system in protostomes is the rhodopsin-retinochrome system of cephalopods, which consists of rhodopsin, the photoisomerase retinochrome and the protein RALBP functioning as shuttle for retinal. In this study we investigate the expression of the rhodopsin-retinochrome system and functional components of the vertebrate visual cycle in a polyplacophoran mollusk, Leptochiton asellus, and examine the phylogenetic distribution of the individual components in other protostome animals. Results Tree-based orthology assignments revealed that orthologs of the cephalopod retinochrome and RALBP are present in mollusks outside of cephalopods. By mining our dataset for vertebrate visual cycle components, we also found orthologs of the retinoid binding protein RLBP1, in polyplacophoran mollusks, cephalopods and a phoronid. In situ hybridization and antibody staining revealed that L. asellus retinochrome is co-expressed in the larval chiton photoreceptor cells (PRCs) with the visual rhodopsin, RALBP and RLBP1. In addition, multiple retinal dehydrogenases are expressed in the PRCs, which might also contribute to the rhodopsin-retinochrome system. Conclusions We conclude that the rhodopsin-retinochrome system is a common feature of mollusk PRCs and predates the origin of cephalopod eyes. Our results show that this system has to be extended by adding further components, which surprisingly, are shared with vertebrates.

scholarly journals Author Correction: An in situ activity assay for lysyl oxidases

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Huilei Wang ◽  
Alan Poe ◽  
Lydia Pak ◽  
Kavitha Nandakumar ◽  
Sandeep Jandu ◽  
...  
Keyword(s):  
Activity Assay ◽  
Lysyl Oxidases

scholarly journals PbLAC4-like, activated by PbMYB26, related to the degradation of anthocyanin during color fading in pear

2021 ◽  
Author(s):  
Guangping Zhao ◽  
Fangxin Xiang ◽  
Shichao Zhang ◽  
Junxing Song ◽  
Xieyu Li ◽  
...  
Keyword(s):  
Prokaryotic Expression ◽  
Degradation Mechanism ◽  
Vital Role ◽  
Luciferase Assay ◽  
Activity Assay ◽  
Enzyme Activity Assay ◽  
Red Color ◽  
Color Fading ◽  
Degradation Ability ◽  
Anthocyanin Degradation

Abstract Background Anthocyanin degradation results in the loss of red color in leaves, petals and receptacles during development. But the degradation mechanism is not fully investigated. It is vital to study the degradation mechanism of anthocyanin in pear for promoting the accumulation of anthocyanin and inhibiting the red fading in pear. Results Here, we reported that laccase encoded by PbLAC4-like was associated with anthocyanin degradation in pear. The expression pattern of PbLAC4-like was negatively correlated with the content of anthocyanin during the color fading process of pear leaves, petals and receptacles. Phylogenetic analysis and sequence alignment revealed that PbLAC4-like played a vital role in anthocyanin degradation. Thus, the degradation of anthocyanin induced by PbLAC4-like was further verified by transient assays and prokaryotic expression. More than 80% of anthocyanin compounds were degraded by transiently over-expressed PbLAC4-like in pear fruitlet peel. The activity of crude enzyme to degrade anthocyanin in leaves at different stages was basically consistent with the expression of PbLAC4-like. The anthocyanin degradation ability of prokaryotic induced PbLAC4-like protein was also verified by enzyme activity assay. Besides, we also identified PbMYB26 as a positive regulator of PbLAC4-like. Yeast one-hybrid and dual luciferase assay results showed that PbMYB26 activated PbLAC4-like expression by directly binding to the PbLAC4-like promoter. Conclusions Taken together, the PbLAC4-like activated by PbMYB26, was involved in the degradation of anthocyanin, resulting in the redness fading in different pear tissues.

Impact of enzyme activity assay on indication in liver transplantation for ornithine transcarbamylase deficiency

2012 ◽  
Vol 105 (3) ◽  
pp. 404-407 ◽  
Author(s):  
Taiichi Wakiya ◽  
Yukihiro Sanada ◽  
Taizen Urahashi ◽  
Yoshiyuki Ihara ◽  
Naoya Yamada ◽  
...  
Keyword(s):  
Liver Transplantation ◽  
Enzyme Activity ◽  
Ornithine Transcarbamylase ◽  
Ornithine Transcarbamylase Deficiency ◽  
Activity Assay ◽  
Enzyme Activity Assay
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