ABSTRACT
Neutrophil extracellular traps (NETs) are formed when neutrophils expel their DNA, histones and intracellular proteins into the extracellular space or circulation. NET formation is dependent on autophagy and is mediated by citrullination of histones to allow for the unwinding and subsequent expulsion of DNA. NETs have an important role in the pathogenesis of several sterile inflammatory diseases, including malignancy, therefore we investigated the role of NETs in the setting of pancreatic ductal adenocarcinoma (PDA). Neutrophils isolated from two distinct animal models of PDA had an increased propensity to form NETs following stimulation with platelet activating factor (PAF). Serum DNA, a marker of circulating NET formation, was elevated in tumor bearing animals as well as in patients with PDA. Citrullinated histone H3 expression, a marker of NET formation, was observed in pancreatic tumors obtained from murine models and patients with PDA. Inhibition of autophagy with chloroquine or genetic ablation of receptor for advanced glycation end products (RAGE) resulted in decreased propensity for NET formation, decreased serum DNA and decreased citrullinated histone H3 expression in the pancreatic tumor microenvironment. We conclude that NETs are upregulated in pancreatic cancer through RAGE-dependent/autophagy mediated pathways.
Subject(s)
Autophagy , Carcinoma, Pancreatic Ductal/physiopathology , Extracellular Traps/physiology , Neutrophils/physiology , Pancreatic Neoplasms/physiopathology , Receptor for Advanced Glycation End Products/physiology , Animals , Carcinoma, Pancreatic Ductal/immunology , Female , Humans , Mice , Mice, Knockout , Pancreatic Neoplasms/immunology , Receptor for Advanced Glycation End Products/geneticsABSTRACT
Gene therapy is an attractive method for the treatment of cardiovascular disease. However, using current strategies, induction of gene expression at therapeutic levels is often inefficient. In this study, we show a novel electroporation (EP) method to enhance the delivery of a plasmid expressing an angiogenic growth factor (vascular endothelial growth factor, VEGF), which is a molecule previously documented to stimulate revascularization in coronary artery disease. DNA expression plasmids were delivered in vivo to the porcine heart with or without coadministered EP to determine the potential effect of electrically mediated delivery. The results showed that plasmid delivery through EP significantly increased cardiac expression of VEGF compared with injection of plasmid alone. This is the first report showing successful intracardiac delivery, through in vivo EP, of a protein expressing plasmid in a large animal.
