Assessing acute pancreatitis: A novel method combining live cell imaging with tissue damage evaluation

Acute pancreatitis (AP) is a sudden inflammation of the exocrine part of the pancreas, resulting in self-digestion and destruction of exocrine tissue. The intricate relationship between exocrine and endocrine functions is pivotal, as damage to acinar cells can affect endocrine cell function and vice versa. However, our understanding of these interactions remains limited. An effective strategy for investigating pancreatic cells involves the utilization of live in-situ acute mouse pancreas tissue slice preparations, combined with noninvasive fluorescent calcium labeling of endocrine or exocrine cells, and subsequent analysis using confocal laser scanning microscopy. Nevertheless, this approach encounters inherent conflicts with conventional methodologies employed to histologically assess the severity of tissue damage due to AP in the model. Traditional methods involve fixing and staining tissue samples with hematoxylin and eosin, thereby precluding live-cell imaging. In this study, our objective was to introduce an innovative method utilizing a commercial fluorescence Live/Dead assay that enables calcium imaging and tissue damage assessment in the same sample. This approach was validated against the classical histological grading of AP severity, and we found a good correlation between the classical histological grading method and the in-situ approach employing the Live/Dead assay. The primary advantage of our novel approach lies in its capacity to enable timely and efficient live-cell imaging together with damage assessment in the same tissue, thereby enabling the study of functional consequences of structural damage at the cellular level and reducing the number of animals required for experimentation.