scholarly journals Genetically encoded thiol redox-sensors in the zebrafish model: lessons for embryonic development and regeneration

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Oksana Breus ◽  
Thomas Dickmeis
Keyword(s):  
Embryonic Development ◽  
Tissue Injury ◽  
Zebrafish Model ◽  
Research Fields ◽  
Open Questions ◽  
Downstream Effects ◽  
Imaging Results ◽  
Redox Sensors ◽  
Thiol Redox

AbstractImportant roles for reactive oxygen species (ROS) and redox signaling in embryonic development and regenerative processes are increasingly recognized. However, it is difficult to obtain information on spatiotemporal dynamics of ROS production and signaling in vivo. The zebrafish is an excellent model for in vivo bioimaging and possesses a remarkable regenerative capacity upon tissue injury. Here, we review data obtained in this model system with genetically encoded redox-sensors targeting H2O2 and glutathione redox potential. We describe how such observations have prompted insight into regulation and downstream effects of redox alterations during tissue differentiation, morphogenesis and regeneration. We also discuss the properties of the different sensors and their consequences for the interpretation of in vivo imaging results. Finally, we highlight open questions and additional research fields that may benefit from further application of such sensor systems in zebrafish models of development, regeneration and disease.

scholarly journals Methylenetetrahydrofolate Reductase Deficiency Reduces Brain Microglia in Zebrafish During Embryonic Development and Is Not Corrected by Folic Acid

2021 ◽  
Vol 5 (Supplement_2) ◽  
pp. 925-925
Author(s):  
Rebecca Simonian ◽  
Emanuela Pannia ◽  
Rola Hammoud ◽  
Xiucheng Cui ◽  
Ruslan Kubant ◽  
...  
Keyword(s):  
Folic Acid ◽  
Embryonic Development ◽  
Methylenetetrahydrofolate Reductase ◽  
Fetal Brain ◽  
Neutral Red ◽  
High Dose ◽  
Head Region ◽  
Zebrafish Model ◽  
Mthfr Deficiency

Abstract Objectives Neuronal development and function is dependent on the interaction between the central nervous system and immune system. Microglia are resident macrophages of the brain critical for regulating neuronal activity during embryonic development. 5-methyltetrahydrofolate (5MTHF), the bioactive folate form, is essential for fetal brain development and immune function. Common variants in methylenetetrahydrofolate reductase (MTHFR), required for conversion of folic acid (FA) to 5-MTHF, limits its production. High dose FA supplementation is recommended but high FA may have the converse effect of reducing MTHFR activity. The objective of this study was to determine the effects of mthfr deficiency and its interaction with FA during embryonic development on microglia in a zebrafish model. Methods The mthfr gene in zebrafish was disrupted using two CRISPR mutagenesis methods. A set of 4 guide RNAs (gRNAs) + cas9 protein or cas9 alone (control) were injected to assay F0 zebrafish, or 2 gRNAs + cas9 mRNA were used to induce a germline mutation. To visualize macrophages at 4 days post fertilization (dpf) in live zebrafish, the transgenic mpeg1: mcherry line was used. In a subset of embryos, FA was added at 0, 50, 75, or 100- μM from 0–4dpf. At 4dpf, live neutral red staining for microglia was performed and the number in the optic tectum was quantified. 5MTHF, s-adenosylmethionine (SAM) and s-adenosylhomocysteine (SAH) were assayed in whole zebrafish at 5dpf. Results In vivo imaging revealed a reduction in macrophage number (∼30%, P < 0.001) in the head region of mthfr disrupted zebrafish, but not in the periphery. mthfr zebrafish also had less microglia compared to controls (15%, P < 0.001). These changes were associated with lower 5MTHF (90%, P < 0.0001) and SAM: SAH (∼50%, P < 0.001) at 5dpf indicative of lower methylation potential. Exposure with FA did not correct the phenotype and at 100µM FA, control zebrafish also showed a decrease in microglia similar to mthfr zebrafish, confirming inhibitory effects of the high FA dose. Conclusions mthfr deficiency reduces microglia in zebrafish but supplementation with FA does not prevent and may exacerbate the negative effects. The 5MTHF form of folate may be a better alternative to FA for brain health in patients with underlying genetic conditions. Funding Sources Supported by CIHR-INMD.

scholarly journals Lipid Metabolism in Bovine Oocytes and Early Embryos under In Vivo, In Vitro, and Stress Conditions

2021 ◽  
Vol 22 (7) ◽  
pp. 3421
Author(s):  
Fabiana de Andrade Melo-Sterza ◽  
Ralf Poehland
Keyword(s):  
Lipid Metabolism ◽  
Embryonic Development ◽  
Stress Conditions ◽  
Developmental Competence ◽  
Additional Stress ◽  
Developmental Potential ◽  
Open Questions ◽  
Potential Reservoir

Lipids are a potential reservoir of energy for initial embryonic development before activation of the embryonic genome and are involved in plasma membrane biosynthesis. Excessive lipid droplet formation is detrimental to cryotolerance and is related to alterations in mitochondrial function, which likely affects lipid metabolism. Increased lipid accumulation in in vitro produced embryos is a consequence of the stress during in vitro embryonic development process. There are several open questions concerning embryo lipid metabolism and developmental potential. Oocyte maturation and embryo development in vivo and in vitro may vary if the donors are subjected to any type of stress before follicle puncture because crucial changes in oocyte/embryonic metabolism occur in response to stress. However, little is known about lipid metabolism under additional stress (such as heat stress). Therefore, in this review, we aimed to update the information regarding the energy metabolism of oocytes and early bovine embryos exhibiting developmental competence, focusing on lipid metabolic pathways observed under in vivo, in vitro, and stress conditions.

scholarly journals PGE2 production at sites of tissue injury promotes an anti-inflammatory neutrophil phenotype and determines the outcome of inflammation resolution in vivo

2017 ◽  
Author(s):  
Catherine A. Loynes ◽  
Jou A. Lee ◽  
Anne L. Robertson ◽  
Michael JG. Steel ◽  
Felix Ellett ◽  
...  
Keyword(s):  
Tissue Injury ◽  
Neutrophil Migration ◽  
Chronic Inflammatory Disease ◽  
Lipid Mediator ◽  
Prostaglandin E ◽  
Zebrafish Model ◽  
Reverse Migration ◽  
Anti Inflammatory ◽  
Inflammation Resolution

AbstractNeutrophils are the first immune cells recruited to a site of injury or infection, where they perform many functions. Having completed their role, neutrophils must be removed from the inflammatory site - either by apoptosis and efferocytosis or by reverse migration away from the wound - for restoration of normal tissue homeostasis. Disruption of these tightly controlled physiological processes of neutrophil removal can lead to a range of inflammatory diseases. We used an in vivo zebrafish model to understand the role of lipid mediator production in neutrophil removal. Following tailfin amputation in the absence of macrophages, neutrophillic inflammation does not resolve. This is due to loss of macrophage-dependent production of eicosanoid prostaglandin E2, which drives neutrophil removal via promotion of reverse migration. Knockdown of endogenous prostaglandin E synthase gene reveals PGE2 as essential for neutrophil inflammation resolution. Furthermore, PGE2 is able to signal through EP4 receptors to enhance Alox15 production, causing a switch towards anti-inflammatory eicosanoid signalling, specifically Lipoxin A4. Our data confirm regulation of neutrophil migration by PGE2 and LXA4 in an in vivo model of inflammation resolution. This pathway may contain therapeutic targets for driving inflammation resolution in chronic inflammatory disease.

1108: Treatment Strategy Improves the in Vivo Stone Comminution Efficiency and Reduces Renal Tissue Injury During Shock Wave Lithotripsy

2005 ◽  
Vol 173 (4S) ◽  
pp. 300-301
Author(s):  
Michaella E. Maloney ◽  
Pei Zhong ◽  
Charles G. Marguet ◽  
Yufeng F. Zhou ◽  
Jeffrey C. Sung ◽  
...  
Keyword(s):  
Shock Wave ◽  
Treatment Strategy ◽  
Shock Wave Lithotripsy ◽  
Tissue Injury ◽  
Renal Tissue

Factors Influencing Leukocyte Adherence in Microvessels

1977 ◽  
Vol 38 (04) ◽  
pp. 0823-0830 ◽  
Author(s):  
Mayrovttz N. Harvey ◽  
Wiedeman P. Mary ◽  
Ronald F. Tuma
Keyword(s):  
Blood Flow ◽  
Shear Stress ◽  
Tissue Injury ◽  
Threshold Value ◽  
In Vivo Studies ◽  
Leukocyte Adherence ◽  
Rolling Velocity ◽  
Subsequent Behavior ◽  
Flow Stasis

SummaryIn vivo studies of the microcirculation of an untraumatized and unanesthetized animal preparation has shown that leukocyte adherence to vascular endothelium is an extremely rare occurrence. Induction of leukocyte adherence can be produced in a variety of ways including direct trauma to the vessels, remote tissue injury via laser irradiation, and denuding the epithelium overlying the observed vessels. The role of blood flow and local hemodynamics on the leukocyte adherence process is quite complex and still not fully understood. From the results reported it may be concluded that blood flow stasis will not produce leukocyte adherence but will augment pre-existing adherence. Studies using 2 quantitative measures of adherence, leukocyte flux and leukocyte velocity have shown these parameters to be affected differently by local hemodynamics. Initial adherence appears to be critically dependent on the magnitude of the blood shear stress at the vessel wall as evidenced by the lack of observable leukocyte flux above some threshold value. Subsequent behavior of the leukocytes as characterized by their average rolling velocity shows no apparent relationship to shear stress but, for low velocities, may be related to the linear blood velocity.

Healing effects of curcumin nanoparticles in deep tissue injury mouse model.

2020 ◽  
Vol 18 ◽  
Author(s):  
Zirui Zhang ◽  
Shangcong Han ◽  
Panpan Liu ◽  
Xu Yang ◽  
Jing Han ◽  
...  
Keyword(s):  
Wound Healing ◽  
Mrna Expression ◽  
Tissue Injury ◽  
Inflammatory Cells ◽  
Pcr Analysis ◽  
Protective Effects ◽  
Deep Tissue ◽  
Deep Tissue Injury

Background: Chronic inflammation and lack of angiogenesis are the important pathological mechanisms in deep tissue injury (DTI). Curcumin is a well-known anti-inflammatory and antioxidant agent. However, curcumin is unstable under acidic and alkaline conditions, and can be rapidly metabolized and excreted in the bile, which shortens its bioactivity and efficacy. Objective: This study aimed to prepare curcumin-loaded poly (lactic-co-glycolic acid) nanoparticles (CPNPs) and to elucidate the protective effects and underlying mechanisms of wound healing in DTI models. Methods: CPNPs were evaluated for particle size, biocompatibility, in vitro drug release and their effect on in vivo wound healing. Results : The results of in vivo wound closure analysis revealed that CPNP treatments significantly improved wound contraction rates (p<0.01) at a faster rate than other three treatment groups. H&E staining revealed that CPNP treatments resulted in complete epithelialization and thick granulation tissue formation, whereas control groups resulted in a lack of compact epithelialization and persistence of inflammatory cells within the wound sites. Quantitative real-time PCR analysis showed that treatment with CPNPs suppressed IL-6 and TNF-α mRNA expression, and up-regulated TGF-β, VEGF-A and IL-10 mRNA expression. Western blot analysis showed up-regulated protein expression of TGF-β, VEGF-A and phosphorylatedSTAT3. Conclusion: Our results showed that CPNPs enhanced wound healing in DTI models, through modulation of the JAK2/STAT3 signalling pathway and subsequent upregulation of pro-healing factors.

scholarly journals Stamina-Enhancing Effects of Human Adipose-Derived Stem Cells

2021 ◽  
Vol 30 ◽  
pp. 096368972110354
Author(s):  
Eun-Jung Yoon ◽  
Hye Rim Seong ◽  
Jangbeen Kyung ◽  
Dajeong Kim ◽  
Sangryong Park ◽  
...  
Keyword(s):  
Physical Activity ◽  
Stem Cells ◽  
Locomotor Activity ◽  
Tissue Injury ◽  
Male Rats ◽  
Adipose Derived Stem Cells ◽  
Sprague Dawley ◽  
Serum Triglycerides

Stamina-enhancing effects of human adipose derived stem cells (hADSCs) were investigated in young Sprague-Dawley rats. Ten-day-old male rats were transplanted intravenously (IV) or intracerebroventricularly (ICV) with hADSCs (1 × 106 cells/rat), and physical activity was measured by locomotor activity and rota-rod performance at post-natal day (PND) 14, 20, 30, and 40, as well as a forced swimming test at PND 41. hADSCs injection increased the moving time in locomotor activity, the latency in rota-rod performance, and the maximum swimming time. For the improvement of physical activity, ICV transplantation was superior to IV injection. In biochemical analyses, ICV transplantation of hADSCs markedly reduced serum creatine phosphokinase, lactate dehydrogenase, alanine transaminase, and muscular lipid peroxidation, the markers for muscular and hepatic injuries, despite the reduction in muscular glycogen and serum triglycerides as energy sources. Notably, hADSCs secreted brain-derived neurotrophic factor (BDNF) and nerve growth factor in vitro, and increased the level of BDNF in the brain and muscles in vivo. The results indicate that hADSCs enhance physical activity including stamina not only by attenuating tissue injury, but also by strengthening the muscles via production of BDNF.

scholarly journals Fractional diffusion models of cardiac electrical propagation: role of structural heterogeneity in dispersion of repolarization

2014 ◽  
Vol 11 (97) ◽  
pp. 20140352 ◽  
Author(s):  
Alfonso Bueno-Orovio ◽  
David Kay ◽  
Vicente Grau ◽  
Blanca Rodriguez ◽  
Kevin Burrage
Keyword(s):  
Structural Heterogeneity ◽  
Biological Tissues ◽  
Tissue Level ◽  
Fractional Diffusion ◽  
Diffusion Models ◽  
Excitable Media ◽  
Research Fields ◽  
Dispersion Of Repolarization ◽  
Electrical Propagation

Impulse propagation in biological tissues is known to be modulated by structural heterogeneity. In cardiac muscle, improved understanding on how this heterogeneity influences electrical spread is key to advancing our interpretation of dispersion of repolarization. We propose fractional diffusion models as a novel mathematical description of structurally heterogeneous excitable media, as a means of representing the modulation of the total electric field by the secondary electrical sources associated with tissue inhomogeneities. Our results, analysed against in vivo human recordings and experimental data of different animal species, indicate that structural heterogeneity underlies relevant characteristics of cardiac electrical propagation at tissue level. These include conduction effects on action potential (AP) morphology, the shortening of AP duration along the activation pathway and the progressive modulation by premature beats of spatial patterns of dispersion of repolarization. The proposed approach may also have important implications in other research fields involving excitable complex media.

Further studies on free-radical pathology in the major central nervous system disorders: effect of very high doses of methylprednisolone on the functional outcome, morphology, and chemistry of experimental spinal cord impact injury

1982 ◽  
Vol 60 (11) ◽  
pp. 1415-1424 ◽  
Author(s):  
H. B. Demopoulos ◽  
E. S. Flamm ◽  
M. L. Seligman ◽  
D. D. Pietronigro ◽  
J. Tomasula ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Free Radical ◽  
Tissue Injury ◽  
Functional Restoration ◽  
Radical Reactions ◽  
Free Radical Reactions ◽  
Cord Injury

The hypothesis that pathologic free-radical reactions are initiated and catalyzed in the major central nervous system (CNS) disorders has been further supported by the current acute spinal cord injury work that has demonstrated the appearance of specific, cholesterol free-radical oxidation products. The significance of these products is suggested by the fact that: (i) they increase with time after injury; (ii) their production is curtailed with a steroidal antioxidant; (iii) high antioxidant doses of the steroidal antioxidant which curtail the development of free-radical product prevent tissue degeneration and permit functional restoration. The role of pathologic free-radical reactions is also inferred from the loss of ascorbic acid, a principal CNS antioxidant, and of extractable cholesterol. These losses are also prevented by the steroidal antioxidant. This model system is among others in the CNS which offer distinctive opportunities to study, in vivo, the onset and progression of membrane damaging free-radical reactions within well-defined parameters of time, extent of tissue injury, correlation with changes in membrane enzymes, and correlation with readily measurable in vivo functions.

scholarly journals Ways into Understanding HIF Inhibition

Cancers ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 159
Author(s):  
Tina Schönberger ◽  
Joachim Fandrey ◽  
Katrin Prost-Fingerle
Keyword(s):  
Protein Interactions ◽  
Target Genes ◽  
Protein Protein Interactions ◽  
Low Oxygen ◽  
Drug Candidates ◽  
Open Questions ◽  
Wide Range ◽  
Hif Pathway

Hypoxia is a key characteristic of tumor tissue. Cancer cells adapt to low oxygen by activating hypoxia-inducible factors (HIFs), ensuring their survival and continued growth despite this hostile environment. Therefore, the inhibition of HIFs and their target genes is a promising and emerging field of cancer research. Several drug candidates target protein–protein interactions or transcription mechanisms of the HIF pathway in order to interfere with activation of this pathway, which is deregulated in a wide range of solid and liquid cancers. Although some inhibitors are already in clinical trials, open questions remain with respect to their modes of action. New imaging technologies using luminescent and fluorescent methods or nanobodies to complement widely used approaches such as chromatin immunoprecipitation may help to answer some of these questions. In this review, we aim to summarize current inhibitor classes targeting the HIF pathway and to provide an overview of in vitro and in vivo techniques that could improve the understanding of inhibitor mechanisms. Unravelling the distinct principles regarding how inhibitors work is an indispensable step for efficient clinical applications and safety of anticancer compounds.

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