Targeted Knockdown of Genes in the Choroid Plexus
June 16th, 2023
Here, we describe a method to selectively alter gene expressions in the choroid plexus while avoiding any impact in other brain areas.
The objective of this research is to investigate the techniques for manipulating gene expression in the choroid plexus. Our study has introduced two methods that allow for technique exclusively in the choroid plexus without any discernible impact on other regions. Our findings can potentially enhance future function studies of the choroid plexus in neuroscience.
Our research has reviewed that inhibiting T-cell infiltration across the choroid plexus through selective lockdown of adenosine to a receptor is sufficient to protect mice from EAE pathology. This finding supports the notion that detecting gateway activity in the choroid plexus could present a promising new strategy for treating multiple sclerosis. This study presents two alternative methods for gene expression manipulation in the choroid plexus.
ICV injection of Cre recombinase into those transgenic mice or ICV injection of AAV2/5, or it's targeted SHI in the WT mice. These methods overcome issues with promoting specificity and transgenetic mouse breeding. To begin, place the anesthetized mice on the surgical platform.
After trimming the hair, apply eye ointment down both eyes to prevent them from drying. Then fix the mice onto a stereotaxic apparatus for immobilization. Make a small incision under a microscope to fully expose the skull.
Prepare two 10 microliter syringes, one containing AAV2/5 adenosine 2A receptor shRNA, and the other containing AAV2/5 scramble. Then use the microscope to locate the bregma and lambda, and set the coordinate point on the 10 microliter syringe based on the mouse brain stereotaxic atlas. Drill a small hole in the skull at the established coordinate point.
Inject two microliters of AAV2/5 adenosine 2A receptor shRNA virus into the brain ventricle via lateral injection at a steady rate of 100 nanoliters per minute. Keep the needle in place for 10 minutes before withdrawing. Seal the injured skin promptly using medical bio fibrin glue to prevent virus loss.
Place the mouse on a heating pad, maintaining its body temperature approximately at 37 degrees Celsius to facilitate recovery. Inject two microliters of CRE-TAT Recombinase into each lateral ventricle of a Rosa-LDL-td Tomato mouse for the experimental group, and two microliters of sterile PBS for the control group. Two weeks after the CRE-TAT recombinase injection, prepare frozen tissue sections, perform nuclear staining, and prepare the slide for imaging.
Knocking down adenosine 2A receptor in the choroid plexus in homozygous adenosine 2A receptor floxed mouse using CRE-TAT led to decreased EAE clinical scores. Similarly, knocking down choroid plexus and adenosine 2A receptor wild-type mice using AAV2/5-shRNA decreased EAE clinical scores. The QPCR analysis showed that the mRNA levels of adenosine 2A receptor decreased in the AAV2/5-shRNA and CRE-TAT groups compared to each control.
Silencing adenosine 2A receptor specifically in the choroid plexus reduced immune cell infiltration into the spinal cord.
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Overview
This research explores techniques for selectively altering gene expressions in the choroid plexus without affecting other brain areas. The study introduces two methods to manipulate gene expression specifically within this region, potentially providing insights into its function and implications for diseases like multiple sclerosis.
Key Study Components
Area of Science
- Neuroscience
- Gene expression manipulation
- Multiple sclerosis research
Background
- The choroid plexus plays a critical role in brain homeostasis and immune responses.
- Understanding its function can provide insights into neurological diseases.
- Previous studies indicate its involvement in conditions like EAE pathology.
- Specific gene manipulation methods are crucial for targeted research.
Purpose of Study
- To investigate methods for targeted gene expression alteration in the choroid plexus.
- To develop techniques that minimize off-target effects in other brain regions.
- To explore the therapeutic potential of modulating immune responses in neurological conditions.
Methods Used
- The study utilized intracerebroventricular (ICV) injections for gene delivery.
- Mouse models, including transgenic and wild-type, were employed to assess gene manipulation.
- Key methods involved the use of Cre recombinase and AAV2/5 vectors.
- Experimental protocols included surgical procedures for anesthetized mice and subsequent tissue analysis.
- Following treatment, QPCR analysis was conducted to evaluate gene expression changes.
Main Results
- Targeted knockdown of the adenosine 2A receptor in the choroid plexus reduced clinical scores in EAE models.
- Gene silencing specifically decreased immune cell infiltration into the spinal cord.
- QPCR results demonstrated a significant reduction in mRNA levels of the adenosine 2A receptor.
- Both methods successfully demonstrated specificity in gene manipulation.
Conclusions
- This study demonstrates that specific gene expression manipulation in the choroid plexus can influence immune responses in neurological diseases.
- Findings suggest a potential new therapeutic strategy for treating conditions like multiple sclerosis.
- This work enhances understanding of immune regulation within the central nervous system.
Frequently Asked Questions
Executive Industry Relevance
Selective gene knockdown in the choroid plexus (ChP) enables precise interrogation of CNS immune gateway mechanisms, addressing a critical challenge in neuroimmunology target validation. This approach enhances predictive confidence for target engagement and mechanistic de-risking in early-stage CNS disorder pipelines. The method supports portfolio decisions by enabling functional studies of ChP-specific gene roles without confounding effects from other brain regions.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Enables functional validation of ChP-specific targets implicated in CNS immune regulation.
- Supports mechanistic de-risking by isolating gene function within a disease-relevant CNS gateway.
- Facilitates hypothesis-driven interrogation of immune cell infiltration pathways in neuroinflammation models.
Screening & Assay Development
- Provides a validated system for quantifying gene knockdown effects on immune cell trafficking.
- Enables reproducible measurement of mRNA levels and clinical phenotypes post-intervention.
- Supports assay standardization for downstream compound screening targeting ChP-mediated pathways.
Translational & Preclinical Research
- Aligns with disease-relevant models of neuroinflammation, such as EAE, for translational biomarker development.
- Enables continuity from genetic manipulation to preclinical efficacy readouts in CNS immune modulation.
- Supports risk-adjusted advancement of ChP-targeted therapeutic hypotheses.
Pipeline & Workflow Integration
This gene knockdown method integrates at the interface of early discovery and preclinical validation for CNS immune targets.
- Discovery Biology: Supports hypothesis testing of ChP-mediated immune cell entry and target function.
- Screening: Provides quantitative mRNA and clinical score outputs for comparative analysis.
- Analytics: Enables QPCR-based measurement of gene silencing and immune infiltration endpoints.
- Translational Research: Bridges mechanistic studies to disease-relevant preclinical models of neuroinflammation.
- Enterprise Reuse: Establishes a reusable platform for ChP-targeted gene modulation across CNS indications.
Operational & Enterprise Impact
- Scientific Value: Increases predictive confidence in ChP target validation and reduces mechanistic ambiguity in CNS immune studies.
- Operational Value: Delivers standardized, reproducible gene knockdown with minimal off-target effects.
- Strategic Value: Informs go/no-go decisions for ChP-targeted programs and optimizes resource allocation.
- Portfolio Impact: Enables risk-adjusted prioritization of CNS immune modulation assets.
Implementation Considerations
- Requires expertise in stereotaxic surgery and CNS-targeted gene delivery.
- Demands access to AAV vector production or Cre recombinase reagents and QPCR analytics.
- Necessitates cross-team standardization of injection coordinates and tissue processing.
- Adaptation may be needed for different mouse strains or CNS disease models.
- Potential limitations include delivery efficiency and variability in gene knockdown across subjects.
