SOCE induced calcium overload regulates autophagy in acute pancreatitis via calcineurin activation

Acute pancreatitis (AP) is an acute inflammatory process of the pancreas that is characterized by inflammation, edema, vacuolization and necrosis, which has significant morbidity and lethality. The pathogenesis of AP has not been established completely. An early and critical feature of AP is the aberrant signaling of Calcium (Ca²⁺) within the pancreatic acinar cell, termed Ca²⁺ overload. Store-operated Ca²⁺ (SOC) channels are the principal Ca²⁺ influx channels that contribute to Ca²⁺ overload in pancreatic acinar cells. Store-operated Ca²⁺ entry (SOCE) has been proved to be a key pathogenic step in AP development that leads to trypsin activation, inflammation and vacuolization. However, the molecular mechanisms are still poorly understood. By establishing Ca²⁺ overload model and mouse AP model using caerulein, we found that caerulein triggered SOCE via inducing interaction between STIM1 and Orai1, which activated calcineurin (CaN); CaN activated the nuclear factor of activated T cells (NFAT) and transcription factor EB (TFEB), thus promoting the transcriptional activation of multiple chemokines genes and autophagy-associated genes respectively. To the best of our knowledge, this is the first evidence showing that SOCE activates TFEB via CaN activation, which may have noticeable longer-term effects on autophagy and vacuolization in AP development. Our findings reveal the role for SOCE/CaN in AP development and provide potential targets for AP treatment.