PUBLICATION

Brain Ventricular Microinjections of Lipopolysaccharide into Larval Zebrafish to Assess Neuroinflammation and Neurotoxicity

Authors
He, Y., Lee, S.M.Y.
ID
ZDB-PUB-220914-14
Date
2022
Source
Journal of visualized experiments : JoVE   (186): (Journal)
Registered Authors
Keywords
none
MeSH Terms
  • Animals
  • Brain/pathology
  • Humans
  • Inflammation/chemically induced
  • Inflammation/metabolism
  • Interleukin-6
  • Larva/metabolism
  • Lipopolysaccharides*/immunology
  • Microinjections
  • Neuroinflammatory Diseases
  • Neurotoxicity Syndromes*/pathology
  • Nitric Oxide/therapeutic use
  • RNA, Messenger/therapeutic use
  • Tumor Necrosis Factor-alpha/metabolism
  • Zebrafish/metabolism
PubMed
36094271 Full text @ J. Vis. Exp.
Abstract
Neuroinflammation is a key player in various neurological disorders, including neurodegenerative diseases. Therefore, it is of great interest to research and develop alternative in vivo neuroinflammation models to understand the role of neuroinflammation in neurodegeneration. In this study, a larval zebrafish model of neuroinflammation mediated by ventricular microinjection of lipopolysaccharide (LPS) to induce an immune response and neurotoxicity was developed and validated. The transgenic zebrafish lines elavl3:mCherry, ETvmat2:GFP, and mpo:EGFP were used for real-time quantification of brain neuron viability by fluorescence live imaging integrated with fluorescence intensity analysis. The locomotor behavior of zebrafish larvae was recorded automatically using a video-tracking recorder. The content of nitric oxide (NO), and the mRNA expression levels of inflammatory cytokines including interleukin-6 (IL-6), interleukin-1β (IL-1β), and human tumor necrosis factor α (TNF-α) were investigated to assess the LPS-induced immune response in the larval zebrafish head. At 24 h after the brain ventricular injection of LPS, loss of neurons and locomotion deficiency were observed in zebrafish larvae. In addition, LPS-induced neuroinflammation increased NO release and the mRNA expression of IL-6, IL-1β, and TNF-α in the head of 6 days post fertilization (dpf) zebrafish larvae, and resulted in the recruitment of neutrophils in the zebrafish brain. In this study, injection of zebrafish with LPS at a concentration of 2.5-5 mg/mL at 5 dpf was determined as the optimum condition for this pharmacological neuroinflammation assay. This protocol presents a new, quick, and efficient methodology for brain ventricle microinjection of LPS to induce LPS-mediated neuroinflammation and neurotoxicity in a zebrafish larva, which is useful for studying neuroinflammation and could also be used as a high-throughput in vivo drug screening assay.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping