In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field

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Inflammation and cell death are critical to pathogenesis of acute pancreatitis. Here we show that transcription factor nuclear factor-κB (NF-κB), which regulates these processes, is activated and plays a role in rat cerulein pancreatitis. NF-κB was strongly activated in the pancreas within 30 min of cerulein infusion; a second phase of NF-κB activation was prominent at 3–6 h. This biphasic kinetics could result from observed transient degradation of the inhibitory protein IκBα and slower but sustained degradation of IκBβ. The hormone also caused NF-κB translocation and IκB degradation in vitro in dispersed pancreatic acini. Both p65/p50 and p50/p50, but not c-Rel, NF-κB complexes were manifest in pancreatitis and in isolated acini. Coinfusion of CCK JMV-180, which abolishes pancreatitis, prevented cerulein-induced NF-κB activation. The second but not early phase of NF-κB activation was inhibited by a neutralizing tumor necrosis factor-α antibody. Antioxidant N-acetylcysteine (NAC) blocked NF-κB activation and significantly improved parameters of pancreatitis. In particular, NAC inhibited intrapancreatic trypsin activation and mRNA expression of cytokines interleukin-6 and KC, which were dramatically induced by cerulein. The results suggest that NF-κB activation is an important early event that may contribute to inflammatory and cell death responses in acute pancreatitis.

The aim of this study was to determine whether tumor necrosis factor-␣ (TNF ␣ )

One reason why pancreatic cancer is so aggressive and unresponsive to treatments is its resistance to apoptosis. We report here that reactive oxygen species (ROS) are a prosurvival, antiapoptotic factor in pancreatic cancer cells. Human pancreatic adenocarcinoma MIA PaCa-2 and PANC-1 cells generated ROS, which was stimulated by growth factors (serum, insulin-like growth factor I, or fibroblast growth factor-2). Growth factors also stimulated membrane NAD(P)H oxidase activity in these cells. Both intracellular ROS and NAD(P)H oxidase activity were inhibited by antioxidants tiron and N-acetylcysteine and the inhibitor of flavoprotein-dependent oxidases, diphenylene iodo- Pancreatic adenocarcinoma is an aggressive malignancy resistant to chemotherapy and radiotherapy (1). One mechanism mediating pancreatic cancer aggressiveness and unresponsiveness to treatment is its resistance to apoptosis. Constitutive activation of antiapoptotic proteins such as transcription factors NF-B (2) and signal transducers and activators of transcription (3), heat shock proteins (4), or phosphatidylinositide 3-kinase (5) is thought to contribute to pancreatic cancer resistance to apoptosis. We hypothesized that a key factor mediating this resistance is ROS 1 generated in pancreatic cancer cells. Although ROS have long been thought to promote cell death (6 -8), recent data (9 -12) suggest that they may also play a prosurvival role. ROS can activate the above mentioned antiapoptotic signaling pathways. In this regard, we recently showed (13) (12, 19 -21). Furthermore, functional components of the phagocytic NAD(P)H oxidase have been found to mediate superoxide production in some nonphagocytic cells (22,23). Other ROS-generating enzymes are xanthine oxidase, nitric-oxide synthase (NOS), phospholipase A 2 (PLA 2 ), and lipoxygenases (14). A growing body of evidence indicates that ROS play signaling roles in physiologic and pathophysiologic processes, including proliferation (24), adhesion (25), and hypertension (17, 26). In particular, growth factors are known to stimulate ROS in a variety of cell types through receptor-transducing pathways,

Inflammation and autophagy are cellular defense mechanisms. When these processes are deregulated (deficient or overactivated) they produce pathologic effects, such as oxidative stress, metabolic impairments, and cell death. Unresolved inflammation and disrupted regulation of autophagy are common features of pancreatitis and pancreatic cancer. Furthermore, obesity, a risk factor for pancreatitis and pancreatic cancer, promotes inflammation and inhibits or deregulates autophagy, creating an environment that facilitates the induction and progression of pancreatic diseases. However, little is known about how inflammation, autophagy, and obesity interact to promote exocrine pancreatic disorders. We review the roles of inflammation and autophagy, and their deregulation by obesity, in pancreatic diseases. We discuss the connections among disordered pathways and important areas for future research.

The pathogenic mechanisms underlying acute pancreatitis are not clear. Two key pathologic acinar cell responses of this disease are vacuole accumulation and trypsinogen activation. We show here that both result from defective autophagy, by comparing the autophagic responses in rodent models of acute pancreatitis to physiologic autophagy triggered by fasting. Pancreatitis-induced vacuoles in acinar cells were greater in number and much larger than those induced with fasting. Degradation of long-lived proteins, a measure of autophagic efficiency, was markedly inhibited in in vitro pancreatitis, while it was stimulated by acinar cell starvation. Further, processing of the lysosomal proteases cathepsin L (CatL) and CatB into their fully active, mature forms was reduced in pancreatitis, as were their activities in the lysosome-enriched subcellular fraction. These findings indicate that autophagy is retarded in pancreatitis due to deficient lysosomal degradation caused by impaired cathepsin processing. Trypsinogen activation occurred in pancreatitis but not with fasting and was prevented by inhibiting autophagy. A marker of trypsinogen activation partially localized to autophagic vacuoles, and pharmacologic inhibition of CatL increased the amount of active trypsin in acinar cells. The results suggest that retarded autophagy is associated with an imbalance between CatL, which degrades trypsinogen and trypsin, and CatB, which converts trypsinogen into trypsin, resulting in intra-acinar accumulation of active trypsin in pancreatitis. Thus, deficient lysosomal degradation may be a dominant mechanism for increased intra-acinar trypsin in pancreatitis.

In different animal models, we find a central role for mitochondrial dysfunction, and for impaired autophagy as its principal downstream effector, in development of AP. In particular, the pathway involving enhanced interaction of cyclophilin D with ATP synthase mediates L-arginine-induced pancreatitis, a model of severe AP the pathogenesis of which has remained unknown. Strategies to restore mitochondrial and/or autophagic function might be developed for treatment of AP.