Molecular and cellular mechanisms of pancreatic injury

Abstract

This review focuses on studies from the past year that highlight molecular and cellular mechanisms of pancreatic injury arising from acute and chronic pancreatitis. Factors that induce or ameliorate injury as well as cellular pathways involved have been examined. Causative or sensitizing factors include refluxed bile acids, hypercalcemia, ethanol, hypertriglyceridemia, and acidosis. In addition, the diabetes drug exendin-4 has been associated with pancreatitis, whereas other drugs may reduce pancreatic injury. The intracellular events that influence disease severity are better understood. Cathepsin-L promotes injury through an antiapoptotic effect, rather than by trypsinogen activation. In addition, specific trypsinogen mutations lead to trypsinogen misfolding, endoplasmic reticulum stress, and injury. Endogenous trypsin inhibitors and upregulation of proteins including Bcl-2, fibroblast growth factor 21, and activated protein C can reduce injury. Immune cells, however, have been shown to increase injury via an antiapoptotic effect. The current findings are critical to understanding how causative factors initiate downstream cellular events resulting in pancreatic injury. Such knowledge will aid in the development of targeted treatments for pancreatitis. This review will first discuss factors influencing pancreatic injury, and then conclude with studies detailing the cellular mechanisms involved.