Screening for Chemical Toxicity Using Cryopreserved Precision Cut Lung Slices

Area of Science:

• Toxicology
• Cell Biology
• Organotypic Assays

Background:

• Current high-throughput screening (HTS) assays for chemical toxicity often use in vitro cell cultures.
• These assays lack the complex in vivo organ microenvironment, leading to discrepancies in results.
• There is a need for more accurate HTS methods that better mimic native organ complexity.

Purpose of the Study:

• To develop and validate a cryopreserved organotypic assay for HTS in predictive toxicology.
• To assess the feasibility of using frozen-thawed precision cut lung slices (PCLS) for HTS.
• To evaluate the correlation between PCLS responses and in vivo lung injury markers.

Main Methods:

• Developed a cryopreserved precision cut lung slice (PCLS) assay.
• Miniaturized the assay into a 96-well plate format for HTS capacity.
• Assessed cell viability, mitochondrial integrity, and glutathione activity in response to zinc chloride (ZnCl2).
• Correlated PCLS responses with lung injury markers from intratracheal instillation studies in rats.

Main Results:

• Frozen-thawed PCLS maintained viability and metabolic activity comparable to other cryopreserved tissues.
• No significant differences were observed in cell viability, mitochondrial integrity, or glutathione activity between fresh and frozen PCLS when exposed to ZnCl2.
• The assay was successfully miniaturized for HTS in a 96-well plate format.
• PCLS responses to ZnCl2 correlated with established markers of lung injury observed in vivo.

Conclusions:

• Cryopreserved PCLS are a feasible and effective model for HTS in predictive toxicology.
• This organotypic assay provides a more accurate representation of in vivo organ responses compared to traditional cell cultures.
• The cryopreserved PCLS assay holds promise for advancing chemical safety assessments.