scholarly journals Tissue-specific modification of cellular bioelectrical activities using the chemogenetic tool, DREADD, in zebrafish

2021 ◽  
Author(s):  
Martin R. Silic ◽  
GuangJun Zhang

Cellular electronic activity plays an essential role in neuronal communication. Manipulation and visualization of cellular membrane potential remain essential tasks in order to study electrical signaling in living organisms. Light-controlled optogenetic and designed chemical-controlled chemogenetic tools were developed to manipulate cellular electric activities for neuroscience research. One of the most common chemogenetic tools is DREADD (designer receptors exclusively activated by designer drugs). It has been extensively utilized due to its convenience and long-lasting effects in murine and primate models, but not in zebrafish, a leading model organism in various research fields. Here, we first establish multiple tissue-specific transgenic zebrafish lines that express two different DREADDs with a genetically encoded voltage indicator, ASAP2s. We observed voltage changes in zebrafish melanophores, epidermis, and neurons by hM4DGi or rM3DGs receptors measured by ASAP2s fluorescence intensity. Alteration to melanophore bioelectricity by DREADD generated dynamic electric signals and resulted in morphological alterations to pigment cells. We also tested a few agonists and found that the latest generation performs better than clozapine N-oxide (CNO). Collectively, our experiments demonstrate that DREADD can be utilized to manipulate cell-specific membrane potential in the zebrafish model. The availability of this tool in zebrafish will offer a new resource for a variety of bioelectricity research fields such as neuroscience, cardiology, and developmental biology.

Dose-Response ◽  
2020 ◽  
Vol 18 (3) ◽  
pp. 155932582093854 ◽  
Author(s):  
Mingming Zhang ◽  
Wei Sun ◽  
Jianan Du ◽  
Yawei Gou ◽  
Lingling Liu ◽  
...  

Purpose: We found in previous study that metformin could treat sepsis myocarditis in a mouse model. We employed the zebrafish model organism to investigate the effect of metformin on sepsis myocarditis. Methods and Results: Wild-type zebrafish was used to establish a sepsis myocarditis model and combined with image software analysis and cytokine detection, the protective dose of metformin was determined. The results showed that immersion with Escherichia coli could cause 75% mortality in zebrafish and make larvae appear as characteristics of severe sepsis myocarditis. Pretreatment with 10 mM metformin for 3 hours could effectively reduce heart congestion and swelling in zebrafish with sepsis myocarditis and increased the heart rate. It could reduce the mortality and prolong the survival time of zebrafish with sepsis myocarditis; Tg(mpx: EGFP) transgenic zebrafish were adopted to explore the number of neutrophils in zebrafish heart before and after metformin protection, and metformin could maintain the number of neutrophils in zebrafish heart; quantitative real-time reverse transcription–polymerase chain reaction showed that metformin could reduce the expression of pro-inflammatory factors, tumor necrosis factor-α and interleukin (IL)-6, and could promote the anti-inflammatory factor, transforming growth factor-β and IL-10 expression. Conclusion: We established a zebrafish sepsis myocarditis model and applied metformin in advance to provide a protective effect on the zebrafish heart.


Cancers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 940
Author(s):  
Chi-Yu Lai ◽  
Kun-Yun Yeh ◽  
Chiu-Ya Lin ◽  
Yang-Wen Hsieh ◽  
Hsin-Hung Lai ◽  
...  

MicroRNA-21 (miR-21) is one of the most frequently upregulated miRNAs in liver diseases such as nonalcoholic fatty liver disease (NAFLD) and hepatocellular carcinoma (HCC). However, mechanistic pathways that connect NAFLD and HCC remain elusive. We developed a doxycycline (Dox)-inducible transgenic zebrafish model (LmiR21) which exhibited an upregulation of miR-21 in the liver, which in turn induced the full spectrum of NAFLD, including steatosis, inflammation, fibrosis, and HCC, in the LmiR21 fish. Diethylnitrosamine (DEN) treatment led to accelerated liver tumor formation and exacerbated their aggressiveness. Moreover, prolonged miR-21 expression for up to ten months induced nonalcoholic steatohepatitis (NASH)-related HCC (NAHCC). Immunoblotting and immunostaining confirmed the presence of miR-21 regulatory proteins (i.e., PTEN, SMAD7, p-AKT, p-SMAD3, and p-STAT3) in human nonviral HCC tissues and LmiR21 models. Thus, we demonstrated that miR-21 can induce NAHCC via at least three mechanisms: First, the occurrence of hepatic steatosis increases with the decrease of ptenb, pparaa, and activation of the PI3K/AKT pathway; second, miR-21 induces hepatic inflammation (or NASH) through an increase in inflammatory gene expression via STAT3 signaling pathways, and induces liver fibrosis through hepatic stellate cell (HSC) activation and collagen deposition via TGF-β/Smad3/Smad7 signaling pathways; finally, oncogenic activation of Smad3/Stat3 signaling pathways induces HCC. Our LmiR21 models showed similar molecular pathology to the human cancer samples in terms of initiation of lipid metabolism disorder, inflammation, fibrosis and activation of the PI3K/AKT, TGF-β/SMADs and STAT3 (PTS) oncogenic signaling pathways. Our findings indicate that miR-21 plays critical roles in the mechanistic perspectives of NAHCC development via the PTS signaling networks.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohamed Helal ◽  
Chuan Yan ◽  
Zhiyuan Gong

An amendment to this paper has been published and can be accessed via a link at the top of the paper.


2021 ◽  
Vol 22 (5) ◽  
pp. 2536
Author(s):  
Rong-Jane Chen ◽  
Chiao-Ching Huang ◽  
Rosita Pranata ◽  
Yu-Hsuan Lee ◽  
Yu-Ying Chen ◽  
...  

Silver nanoparticles pose a potential risk to ecosystems and living organisms due to their widespread use in various fields and subsequent gradual release into the environment. Only a few studies have investigated the effects of silver nanoparticles (AgNPs) toxicity on immunological functions. Furthermore, these toxic effects have not been fully explored. Recent studies have indicated that zebrafish are considered a good alternative model for testing toxicity and for evaluating immunological toxicity. Therefore, the purpose of this study was to investigate the toxicity effects of AgNPs on innate immunity using a zebrafish model and to investigate whether the natural compound pterostilbene (PTE) could provide protection against AgNPs-induced immunotoxicity. Wild type and neutrophil- and macrophage-transgenic zebrafish lines were used in the experiments. The results indicated that the exposure to AgNPs induced toxic effects including death, malformation and the innate immune toxicity of zebrafish. In addition, AgNPs affect the number and function of neutrophils and macrophages. The expression of immune-related cytokines and chemokines was also affected. Notably, the addition of PTE could activate immune cells and promote their accumulation in injured areas in zebrafish, thereby reducing the damage caused by AgNPs. In conclusion, AgNPs may induce innate immune toxicity and PTE could ameliorate this toxicity.


Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 445
Author(s):  
Daniela Zizioli ◽  
Simona Bernardi ◽  
Marco Varinelli ◽  
Mirko Farina ◽  
Luca Mignani ◽  
...  

Zebrafish has proven to be a versatile and reliable experimental in vivo tool to study human hematopoiesis and model hematological malignancies. Transgenic technologies enable the generation of specific leukemia types by the expression of human oncogenes under specific promoters. Using this technology, a variety of myeloid and lymphoid malignancies zebrafish models have been described. Chronic myeloid leukemia (CML) is a clonal myeloproliferative neoplasia characterized by the BCR-ABL1 fusion gene, derived from the t (9;22) translocation causing the Philadelphia Chromosome (Ph). The BCR-ABL1 protein is a constitutively activated tyrosine kinas inducing the leukemogenesis and resulting in an accumulation of immature leukemic cells into bone marrow and peripheral blood. To model Ph+ CML, a transgenic zebrafish line expressing the human BCR-ABL1 was generated by the Gal4/UAS system, and then crossed with the hsp70-Gal4 transgenic line. The new line named (BCR-ABL1pUAS:CFP/hsp70-Gal4), presented altered expression of hematopoietic markers during embryonic development compared to controls and transgenic larvae showed proliferating hematopoietic cells in the caudal hematopoietic tissue (CHT). The present transgenic zebrafish would be a robust CML model and a high-throughput drug screening tool.


2006 ◽  
Vol 103 (41) ◽  
pp. 15166-15171 ◽  
Author(s):  
H. E. Sabaawy ◽  
M. Azuma ◽  
L. J. Embree ◽  
H.-J. Tsai ◽  
M. F. Starost ◽  
...  

genesis ◽  
2015 ◽  
Vol 53 (8) ◽  
pp. 498-509 ◽  
Author(s):  
Leyla Ruzicka ◽  
Yvonne M. Bradford ◽  
Ken Frazer ◽  
Douglas G. Howe ◽  
Holly Paddock ◽  
...  

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2551 ◽  
Author(s):  
Sathyadevi Palanisamy ◽  
Yu-Liang Wang ◽  
Yu-Jen Chen ◽  
Chiao-Yun Chen ◽  
Fu-Te Tsai ◽  
...  

Nitroxyl (HNO) plays a critical role in many physiological processes which includes vasorelaxation in heart failure, neuroregulation, and myocardial contractility. Powerful imaging tools are required to obtain information for understanding the mechanisms involved in these in vivo processes. In order to develop a rapid and high sensitive probe for HNO detection in living cells and the zebrafish model organism, 2-((2-(benzothiazole-2yl)benzylidene) amino)benzoic acid (AbTCA) as a ligand, and its corresponding copper(II) complex Cu(II)-AbTCA were synthesized. The reaction results of Cu(II)-AbTCA with Angeli’s salt showed that Cu(II)-AbTCA could detect HNO quantitatively in a range of 40–360 µM with a detection limit of 9.05 µM. Furthermore, Cu(II)-AbTCA is more selective towards HNO over other biological species including thiols, reactive nitrogen, and reactive oxygen species. Importantly, Cu(II)-AbTCA was successfully applied to detect HNO in living cells and zebrafish. The collective data reveals that Cu(II)-AbTCA could be used as a potential probe for HNO detection in living systems.


2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Gauri Khandekar ◽  
Seongcheol Kim ◽  
Pudur Jagadeeswaran

Platelets play an important role in mammalian hemostasis. Thrombocytes of early vertebrates are functionally equivalent to mammalian platelets. A substantial amount of research has been done to study platelet function in humans as well as in animal models. However, to date only limited functional genomic studies of platelets have been performed but are low throughput and are not cost-effective. Keeping this in mind we introduced zebrafish, a vertebrate genetic model to study platelet function. We characterized zebrafish thrombocytes and established functional assays study not only their hemostatic function but to also their production. We identified a few genes which play a role in their function and production. Since we introduced the zebrafish model for the study of hemostasis and thrombosis, other groups have adapted this model to study genes that are associated with thrombocyte function and a few novel genes have also been identified. Furthermore, transgenic zebrafish with GFP-tagged thrombocytes have been developed which helped to study the production of thrombocytes and their precursors as well as their functional roles not only in hemostasis but also hematopoiesis. This paper integrates the information available on zebrafish thrombocyte function and its formation.


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