The intracellular sensor NOD1 has important host defense functions relating to a variety of pathogens. In studies antecedent to the present study we showed that this molecule also participated in the induction of a non-infectious pancreatitis via its response to commensal organisms. In particular, we showed first that pancreatitis induced by high-dose cerulein (a cholecystokinin receptor agonist) administration depends on NOD1 stimulation by gut microflora. We then analyzed this NOD1 activity using a model of pancreatitis wherein the latter is induced by the simultaneous administration of low-dose of cerulein (that does not itself induce pancreatitis) and FK156, an activator of NOD1 that mimics the effect of gut bacteria that have breached the mucosal barrier. We found that such low-dose cerulein pancreatitis was dependent on acinar cell production of the chemokine MCP-1 and the intra-pancreatic influx of CCR2+ inflammatory cells. Moreover, we established that MCP-1 production involved activation of the transcription factors NF-kappaB and STAT3, each requiring complementary NOD1 and cerulein signaling. These studies thus established that gut commensals enable non-infectious pancreatic inflammation via NOD1 signaling in pancreatic acinar cells. On the basis of these findings we postulate that initial dysruption of pancreatic acinar cells by a variety of stimuli (in this case cerulein) leads to altered gut permeability and the entry of gut bacteria into the circulation. Such bacteria then stimulates NOD1 in acinar cells and the induction of chemokine production that draws inflammatory cells into the pancreas and initiates the pancreatic inflammation. In more recent studies of the relation of NOD1 to pancreatitis we established a chronic pancreatitis model induced by repeated dosing of mice with low dose cerulein and NOD1 ligand. Using this model we established the importance of NOD1 induction of type I interferon in the pathogenesis of chronic pancreatitits via its effect on acinar cell production of IL-33 and down-stream production of IL-13, the latter a cytokine that mediates fibrosis. These new studies emphasize that blockade of NOD1 signaling in the context of pancreatic inflammation is a feasible approach to the treatment of chronic pancreatitis as well as acute pancreatitis. In the light of the above studies showing that NOD1 can be a factor in the induction of an inflammatory state (in this case pancreatitis), it became of interest to try to identify inhibitors of NOD1 that could conceivable prevent experimental pancreatitis and thus ultimately find use as an agent that would be use of treatment of NOD1-dependent human inflammatory disease. Recently, Correa et al (Correa RG Chem Biol 2011, 18:825-832)employed high through-put screening of an NIH library containing >300,000 compounds to identify such NOD1 inhibitors using HEK cells containing an NF-kappaB reporter construct. Using this approach, a 2-aminobenzimidazole compound designated Nodinitib-1 (ML130) has been identified as a potent and specific NOD1 inhibitor that acts by inhibiting the ability of NOD1 to induce intra-cellular trafficking. It should be noted, however, that such inhibition has only been demonstrated by in vitro testing not in the whole animal. We have entered into an M-CRADA with the Sanford-Burnham Medical Research Institute, the sponsors of the above described screening study, to obtain ML130 for use in studies of the ability of ML130 to prevent experimental pancreatitis. This M-CRADA is now fully executed and sufficient M130 has been sent to us for appropriate studies. The latter consists of administration of high dose cerulein or low dose cerulein plus NOD1 ligand together with ML130 to determine if the latter can prevent high dose and low dose cerulein pancreatitis respectively. To facilitate these studies we have so far utilized mice with permanently implaced intravenous catheters so that we can monitor the effects of ML130 on pancreatitis development by measuring blood levels of amylase and MCP-1 (as well as other cytokines and chemokines). In studies conducted so far, we have induced cerulein-pancreatitis using a standard protocol in which pancreatitis is induced by IV administration of cerulein at hourly intervals (X7) followed by assessment of pancreatitis at 8 hours. The capacity of ML130 to prevent development of such pancreatitis was determined in parallel studies in which mice were co-administered cerulein and ML-30 at the initial cerulein injection and at the one hour cerulein injection. We found that ML130 did inhibit pancreatitis development as assessed by serum amylase levels and IL-6 levels in the circulation at one hour after cessation of cerulein administration. This inhibition was statistlcally significant. In addition, we have conducted additional studies in which we explored the potential of ML130 to inhibit cerulein-pancreatitis when given in various doses; we found that even when ML140 was given at a single dose at the initiation of the pancreatitis by cerulein injection it was effective in inhibition of the pancreatitis. The use of mice with permanently implaced intravenous catheters facilitates these studies; however, these mice are expensive and not readily available. This has impeded the full panoply of studies we think are necessary.
| Arai, Yasuyuki; Yamashita, Kouhei; Kuriyama, Katsutoshi et al. (2015) Plasmacytoid Dendritic Cell Activation and IFN-? Production Are Prominent Features of Murine Autoimmune Pancreatitis and Human IgG4-Related Autoimmune Pancreatitis. J Immunol 195:3033-44 |
| Fichtner-Feigl, Stefan; Kesselring, Rebecca; Strober, Warren (2015) Chronic inflammation and the development of malignancy in the GI tract. Trends Immunol 36:451-9 |
| Strober, Warren; Asano, Naoki; Fuss, Ivan et al. (2014) Cellular and molecular mechanisms underlying NOD2 risk-associated polymorphisms in Crohn's disease. Immunol Rev 260:249-60 |
| Strober, Warren (2013) Impact of the gut microbiome on mucosal inflammation. Trends Immunol 34:423-30 |
| Tsuji, Yoshihisa; Watanabe, Tomohiro; Kudo, Masatoshi et al. (2012) Sensing of commensal organisms by the intracellular sensor NOD1 mediates experimental pancreatitis. Immunity 37:326-38 |
