Object orientated automated image analysis: quantitative and qualitative estimation of inflammation in mouse lung

Historically, histopathology evaluation is performed by a pathologist generating a qualitative assessment on thin tissue sections on glass slides. In the past decade, there has been a growing interest for tools able to reduce human subjectivity and improve workload. Whole slide scanning technology combined with object orientated image analysis can offer the capacity of generating fast and reliable results. In the present study, we combined the use of these emerging technologies to characterise a mouse model for chronic asthma. We monitored the inflammatory changes over five weeks by measuring the number of neutrophils and eosinophils present in the tissue, as well as, the bronchiolar associated lymphoid tissue (BALT) area on whole lungs sections. We showed that inflammation assessment could be automated efficiently and reliably. In comparison to human evaluation performed on the same set of sections, computer generated data was more descriptive and fully quantitative. Moreover optimisation of our detection parameters allowed us to be to more sensitive and to generate data in a larger dynamic range to traditional experimental evaluation, such as bronchiolar lavage (BAL) inflammatory cell counts obtained by flow cytometry. We also took advantage of the fact that we could increase the number of samples to be analysed within a day. Such optimisation allowed us to determine the best study design and experimental conditions in order to increase statistical significance between groups. In conclusion, we showed that combination of whole slide digital scanning and image analysis could be fully automated and deliver more descriptive and biologically relevant data over traditional methods evaluating histopathological pulmonary changes observed in this mouse model of chronic asthma

Metabolism

Background: Cardiovascular disease is the leading cause of deaths in nonalcoholic steatohepatitis (NASH) patients. Mouse models, while widely used for drug development, do not fully replicate human NASH nor integrate the associated cardiac dysfunction, i.e. heart failure with preserved ejection fraction (HFpEF). To overcome these limitations, we established a nutritional hamster model developing both NASH and HFpEF. We then evaluated the effects of the dual peroxisome proliferator activated receptor alpha/delta agonist elafibranor developed for the treatment of NASH patients. Methods: Male Golden Syrian hamsters were fed for 10 to 20 weeks with a free choice diet, which presents hamsters with a choice between control chow diet with normal drinking water or a high fat/high cholesterol diet with 10% fructose enriched drinking water. Biochemistry, histology and echocardiography analysis were performed to characterize NASH and HFpEF. Once the model was validated, elafibranor was evaluated at 15 mg/kg/day orally QD for 5 weeks. Results: Hamsters fed a free choice diet for up to 20 weeks developed NASH, including hepatocyte ballooning (as confirmed with cytokeratin-18 immunostaining), bridging fibrosis, and a severe diastolic dysfunction with restrictive profile, but preserved ejection fraction. Elafibranor resolved NASH, with significant reduction in ballooning and fibrosis scores, and improved diastolic dysfunction with significant reduction in E/A and E/E' ratios. Conclusion: Our data demonstrate that the free choice diet induced NASH hamster model replicates the human phenotype and will be useful for validating novel drug candidates for the treatment of NASH and associated HfpEF