Background: The development of accurate and time-efficient preclinical tools predicting the safety and efficacy of new drug candidates is critically important in reducing the cost and duration of pharmaceutical development. Here, we present precision-cut lung slices (PCLS) from preterm rabbit lungs as a screening model for inflammatory drugs in the context of bronchopulmonary dysplasia (BPD), as a time-efficient alternative model sidestepping some of the limitations of using animal models. Compared to in vivo models, PCLS are less expensive and less time-consuming, while still possessing many of the lung-specific features of untouched lungs such as polarity and cellular architecture, small airways, immune cells population and connective tissue. Objective: We aimed to assess the ability of PCLS derived from preterm rabbit lungs to elicit an inflammatory and immune responses after exposing them to either lipopolysaccharide (LPS) or recombinant human Interleukin-1 (rhIL-1). Design/Methods: Preterm rabbits were delivered by C-section after 28 days of gestation and immediately scarified. The lungs were isolated and 20 PCLS were obtained from each lung pair. PCLS were cultured in DMEM-F12 media with antibiotics and antimycotic. To investigate whether cultured PCLS remained functional, either LPS or rh-IL1b were used as a target stimulating compounds. Budesonide, that has been successfully used both in the clinic and in the preterm rabbit model to prevent BPD, was employed as a reference drug to evaluate the modulation of inflammation in the PCLS and to validate this model. TNF-, IL-1, IL-6 and MMP-9 were assessed with qPCR or ELISA, as appropriate. Results: PCLS remained viable, structurally undamaged and able to elicit functional inflammatory responses up to 24h in culture. After 4h incubation with both inflammatory stimuli (LPS or rhIL-1), PCLS expressed a set of pro-inflammatory cytokines, including TNF-, IL-1, IL-6 and MMP-9, which were significantly above baseline levels. Furthermore, cultured PCLS were shown to be capable of generating re-call immune responses, characterized by cytokine production and release into the media. Budesonide treatment significantly reduced the inflammatory status of PCLS at 4 and 24h, thus validating the PCLS set-up as an ex vivo model for anti-inflammatory drug screening.
Conclusion(s): PCLS represent a promising, high-throughput alternative ex vivo tool to evaluate the potential efficacy and toxicity of anti-inflammatory drugs in the context of BPD.
