Precision Cut Lung Slices as an Efficient Tool for Ex vivo Pulmonary Vessel Structure and Contractility Studies
May 24th, 2021
6.2K views
Presented here is a protocol for preserving the vascular contractility of PCLS murine lung tissue, resulting in a sophisticated three-dimensional image of the pulmonary vasculature and airway, which can be preserved for up to 10 days that is susceptible to numerous procedures.
Overview
This article details the preparation and application of precision-cut lung slices (PCLS) from murine models to study pulmonary structure, cellular composition, and vessel contractility. The PCLS method preserves three-dimensional lung architecture and enables live imaging, contractility assays, and molecular analyses, providing a robust ex vivo platform for investigating pulmonary vascular and airway diseases.
Key Study Components
Area of Science
- Pulmonary biology
- Ex vivo tissue modeling
- Vascular physiology
Background
- Traditional lung tissue visualization faces challenges in preserving physiological vessel structure and cellular architecture.
- Standard in vitro contractility assays do not replicate the complex lung environment.
- PCLS offers unbiased, three-dimensional tissue preservation for up to 10 days.
- PCLS enables visualization of genetically labeled cells and assessment of functional responses.
Purpose of Study
- To establish a reproducible protocol for preparing murine PCLS that maintains lung structure and function.
- To demonstrate the utility of PCLS for live imaging and contractility assays.
- To enable downstream molecular analyses such as western blot and RNA extraction from lung slices.
Methods Used
- Dissection and inflation of murine lungs with agarose via tracheal cannulation.
- Preparation of 300 μm lung slices using a vibratome under cold conditions.
- Live imaging of vessel contractility in response to vasoconstrictors (e.g., potassium chloride, endothelin-1) using phase contrast microscopy and time-lapse recording.
- Viability assessment via colorimetric changes and absorbance measurements.
- RNA and protein extraction from frozen, powdered lung slices for molecular analysis.
Main Results
- PCLS maintained viability for up to 10 days, as indicated by colorimetric assays.
- Vessel contractility in response to vasoconstrictors was preserved and visualized in real time.
- Endogenous tdTomato-labeled cells remained detectable in PCLS up to one week post-labeling.
- PCLS enabled successful extraction of RNA and protein for downstream analyses.
Conclusions
- PCLS is a robust ex vivo model that preserves lung structure and function for extended studies.
- The method allows for integrated imaging, functional assays, and molecular analyses.
- PCLS can be adapted for studies of both vascular and airway diseases, and potentially for human lung tissue research.
Frequently Asked Questions
What are the main advantages of using precision-cut lung slices (PCLS)?
PCLS preserves the three-dimensional structure and cellular composition of lung tissue, enabling live imaging, functional assays, and molecular analyses in a physiologically relevant ex vivo environment.
How is lung viability assessed in PCLS preparations?
Viability is monitored by colorimetric changes in the culture medium and absorbance measurements at specific wavelengths, indicating metabolic activity over time.
What types of functional assays can be performed with PCLS?
PCLS allows for vessel and airway contractility assays in response to pharmacological agents, with real-time imaging and time-lapse recording of tissue responses.
Can PCLS be used for molecular analyses?
Yes, RNA and protein can be extracted from PCLS for downstream applications such as western blotting and gene expression analysis.
How are genetically labeled cells visualized in PCLS?
Endogenous fluorescent reporters, such as tdTomato, can be visualized in PCLS using confocal microscopy, allowing for spatial localization of specific cell populations.
What are critical steps for successful PCLS preparation?
Proper lung inflation with agarose and thorough removal of blood are essential for maintaining tissue integrity and enabling high-quality imaging and functional assays.
Can this method be applied to human lung tissue?
Yes, the PCLS technique can be adapted for use with human lung tissue, making it relevant for translational and clinically oriented research.
Executive Industry Relevance
Precision-cut lung slices (PCLS) provide a physiologically relevant ex vivo platform for evaluating pulmonary vessel structure and contractility, addressing key challenges in preserving native tissue architecture and function. This method enables integrated imaging, functional assays, and molecular analyses, supporting predictive confidence in early-stage pulmonary drug discovery. PCLS enhances translational continuity and de-risking for portfolio decisions in pulmonary vascular and airway disease research.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Enables interrogation of pulmonary vessel contractility and signaling pathways in a preserved tissue context.
- Supports biological de-risking by maintaining three-dimensional lung architecture and cellular composition.
- Facilitates functional target validation through live imaging and response to vasoconstrictors.
- Improves predictive confidence for advancing pulmonary targets in the discovery pipeline.
Screening & Assay Development
- Provides validated ex vivo lung tissue for reproducible contractility and viability assays.
- Enables quantitative measurement of vessel responses to pharmacological agents using time-lapse imaging.
- Supports assay standardization and scalability for compound evaluation in pulmonary research.
- Allows for integration with molecular analyses such as RNA and protein extraction.
Translational & Preclinical Research
- Aligns with disease-relevant models for studying pulmonary vascular and airway pathophysiology.
- Maintains translational biomarker continuity by enabling visualization of genetically labeled cells.
- Facilitates risk-adjusted advancement decisions through comprehensive functional and molecular readouts.
- Supports adaptation to human lung tissue for clinically relevant research scenarios.
Pipeline & Workflow Integration
PCLS fits within the discovery continuum from early target validation through preclinical research, enabling integrated functional and molecular analyses of pulmonary tissues.
- Discovery Biology: Supports hypothesis testing and pathway clarification in a physiologically relevant lung model.
- Screening: Delivers reproducible, quantitative contractility and viability outputs for compound assessment.
- Analytics: Provides real-time imaging, absorbance measurements, and molecular data for robust condition comparison.
- Translational Research: Bridges discovery and preclinical validation with disease-relevant tissue and biomarker alignment.
- Enterprise Reuse: Offers a reusable ex vivo platform adaptable to various pulmonary research needs.
Operational & Enterprise Impact
- Scientific Value: Increases predictive confidence and reduces mechanistic ambiguity in pulmonary target validation.
- Operational Value: Enhances standardization, reproducibility, and scalability of lung tissue assays.
- Strategic Value: Improves go/no-go decisions and capital efficiency by providing comprehensive functional and molecular data.
- Portfolio Impact: Enables risk-adjusted prioritization and advancement of pulmonary disease programs.
Implementation Considerations
- Requires expertise in murine lung dissection, tissue handling, and vibratome operation.
- Needs access to confocal microscopy, time-lapse imaging, and molecular analysis infrastructure.
- Demands cross-team standardization for tissue preparation and assay protocols.
- Adaptable to both murine and human lung tissues for broader translational relevance.
- Dependent on precise lung inflation and blood removal for optimal imaging and assay quality.
Biopharma FAQs
Why does null hypothesis testing matter for PCLS-based contractility assays?
Null hypothesis testing in PCLS contractility assays ensures that observed vessel responses to vasoconstrictors are statistically significant and not due to random variation, supporting robust target validation. This approach strengthens confidence in functional readouts for early-stage pulmonary drug discovery. Reliable statistical analysis underpins decision-making for advancing targets in the pipeline.
How does independent variable isolation fit PCLS vessel response studies?
Isolating independent variables, such as specific vasoconstrictors, in PCLS studies allows for precise attribution of contractile responses to defined stimuli. This clarity is essential for mechanistic de-risking and supports the identification of actionable targets in pulmonary research workflows. Controlled variable manipulation enhances reproducibility and interpretability of results.
What do quantitative dependent variable measurements enable in PCLS imaging?
Quantitative measurements, such as vessel diameter changes and absorbance shifts, enable objective assessment of tissue viability and contractility in PCLS imaging. These outputs provide actionable data for comparing compound effects and optimizing assay conditions. Quantitative readouts support data-driven advancement decisions in R&D pipelines.
Why are replication requirements critical for cross-functional PCLS studies?
Replication ensures that PCLS-based findings are consistent and reproducible across different teams and experimental runs, facilitating cross-functional collaboration. Standardized replication builds confidence in assay robustness and supports enterprise-wide adoption of the platform. Reliable replication is key for portfolio-level decision-making and risk management.
What statistical analysis capabilities are needed before PCLS implementation?
Robust statistical analysis capabilities, including significance testing and quantitative comparison of contractility and viability data, are essential before implementing PCLS in R&D workflows. These analyses validate assay performance and ensure that observed effects are meaningful for target evaluation. Statistical rigor underpins the translational value of PCLS-derived data.
Chapters in this video
0:04
Introduction
0:49
Extraction of Mouse Lung
3:34
Precision Cut Lung Slices (PCLS)
5:35
Vasoconstrictor Experiment
6:20
Preparing the Tissue for RNA or Protein Lysis on PCLS
7:26
Results: Ex Vivo Pulmonary Vessel Structure and Contractility Studies of PCLS
8:32
Conclusion
