BACKGROUND:Current reference standards for measuring gastric emptying and motility are not considered optimal due to the time required, ionizing radiation, invasiveness, and spatial resolution. PURPOSE:To assess gastric motility using novel real-time dynamic magnetic resonance imaging in combination with static measurements for gastric emptying and training of an automated deep-learning-based segmentation pipeline. STUDY TYPE:Prospective. PARTICIPANTS:The study included 36 healthy volunteers (20 female, mean 24 ± 3 years) and three patients with diagnosed Crohn's disease. FIELD STRENGTH/SEQUENCES:Participants ingested water to assess fasting motility and pineapple juice for the postprandial state. 3 T, 3D spoiled gradient echo (GRE) sequence and real-time spoiled GRE. ASSESSMENT:Gastric emptying was measured by using the gastric volume, while motility was analyzed by tracking changes in the antrum's cross-sectional area and applying Fast Fourier Transformation. Segmentations were performed using a trained semantic segmentation model. STATISTICAL TESTS:Linear Mixed Model with continuous dependent variables and fixed effects. Models included a random intercept for participants. Statistical significance was defined as p = 0.05. RESULTS:The method enabled volumetric analysis of gastric content from 3D breath-hold static acquisition and time-resolved quantification of peristaltic parameters from real-time FLASH2 imaging at high temporal resolution (here 6.24 fps). Water emptied rapidly and exponentially (t1/2 = 14.77 ± 10.55 min), while juice showed slower emptying (t1/2 = 64.24 ± 11.87 min). Contraction frequencies (fasted: 2.76 ± 0.43 cpm, fed: 2.89 ± 0.43 cpm) and velocities (fasted: 1.67 ± 0.38 mm/s, fed: 1.72 ± 0.37 mm/s) were within physiological ranges, with fasting conditions characterized by stronger occlusion compared to the fed. Measurements taken from three patients proved that the workflow could be used in a clinical context. DATA CONCLUSION:Real-time MRI with AI-based analysis enabled quantitative assessment of gastric emptying and motility, revealing physiological peristaltic parameters and state-dependent differences in occlusion. EVIDENCE LEVEL:2. TECHNICAL EFFICACY:Stage 1.

BackgroundIn patients with pancreatic disease, exocrine insufficiency facilitates sarcopenia. Here, we investigated whether impaired exocrine function in the asymptomatic general population is also associated with sarcopenia.MethodsWe pooled data from two independent cohorts of 5,598 participants without history of pancreatic disease enrolled in the Study of Health in Pomerania. The association between impaired exocrine pancreatic function (fecal elastase ≤ 200 μg/g) and sarcopenia was determined by cross-sectional, univariable and multivariable regression analyses. The relation between baseline fecal elastase levels and incident sarcopenia was tested in a subgroup of 1,587 persons with available 5-years follow-up data.ResultsWe found a baseline prevalence of 4.1% and 9.1% for sarcopenia and impaired exocrine pancreatic function, respectively. While there was no association in persons with age ≥ 65 years, impaired exocrine pancreatic function was associated with the risk of sarcopenia only in younger subjects (OR [95% CI]: 2.52 [1.40; 4.54]). These crude results remained robust in the multivariable models (OR [95% CI]: 2.41 [1.26; 4.61]). Longitudinal analyses did not show an association between exocrine pancreatic function and incident sarcopenia. However, reduced fecal elastase concentration at baseline was associated with muscle mass decline during follow-up. This relation was age-dependent with a significant inverse association only among younger (β [95% CI]: −0.23 [−0.39; −0.08]) but not older study participants (β [95% CI]: 0.04 [−0.31; 0.39]).ConclusionImpaired exocrine pancreatic function is associated with sarcopenia in younger individuals of the general population. Studies are called for testing the effect of pancreatic enzyme replacement therapy in asymptomatic patients with impaired exocrine pancreatic function.

Acute pancreatitis is caused by a premature activation of digestive proteases. One hypothesis is based on the proteolytic activation of the serine protease trypsinogen by the lysosomal enzyme cathepsin B (CTSB) after co-localization in the same subcellular compartment. The ER-cargo receptor protein CLN8 (ceroid lipofuscinosis, neuronal) mediates cathepsin transport from the endoplasmic reticulum (ER), the site of enzyme synthesis, to the trans-Golgi system, from which they are distributed to their final destinations. The aim of this study is to investigate the role of CLN8 in acute pancreatitis and intracellular cathepsin trafficking by using isolated pancreatic acinar cells, a CLN8-deficient (Cln8mnd/MsrJ) mouse model, and 266-6 mouse pancreatic acinar tumor cells in which the Cln8 gene was inactivated by CRISPR/Cas9. Loss of CLN8 mitigated the early phase of acute pancreatitis but did not prevent it completely. We still observed CTSB expression in the endo-lysosomal and secretory compartment albeit enzyme activation was decreased. At later disease stages pancreatic injury increased along with an upregulation of ER-phagy shown by an overexpression of LC3B and the ER-phagy receptor FAM134B as well as autophagolysosome formation and increased ER stress. In summary, our data show that acute pancreatitis still occurs despite disruption of the EGRESS (ER-to-Golgi relaying of enzymes of the lysosomal system) complex implicating alternative intracellular enzyme delivery routes. They also illustrate that ER-stress and ER-phagy aggravate severity at later course of pancreatitis.

BACKGROUND:There is a high malnutrition risk in patients with gastrointestinal tumors. Yet it is unknown when malnutrition manifests and how changes in nutritional status are related to quality of life and fatigue at different stages of oncologic therapy. PATIENTS AND METHODS:In a prospective observational study, we recruited patients with initial diagnosis of any gastrointestinal tumor requiring systemic therapy and respective patients already receiving treatment. Subjects underwent comprehensive nutritional assessment at enrollment and after 3 months. In addition, patients reported data on physical activity (IPAQ-SF), quality of life (SF-12), and fatigue (EORTC QLQ-FA12). Besides baseline associations, relations between changes in nutritional status and patient-reported outcomes during treatment were analyzed. RESULTS:We included 66 patients (mean(±SD) age: 62.1(±10.6) yrs.; 68% male), of which 29 had received initial diagnosis and 37 were already undergoing treatment. Baseline clinical characteristics and nutritional status were comparable between groups. With 88% of patients, GLIM-defined malnutrition was highly prevalent at baseline and associated with fatigue, reduced physical activity, and quality of life (P < .01, respectively). Among 36 study completers, only minor fat mass (P = .033) and progressed weight loss (P = .025) indicated further nutritional deterioration. Development of cachexia, but not malnutrition or sarcopenia, during treatment was associated with impaired patient-reported outcomes, ie, higher fatigue (rho = 0.400; P = .019) and lowered physical activity (rho=-0.423; P = .013). CONCLUSION:Most patients with gastrointestinal cancer are malnourished already at diagnosis. Impaired nutritional status is closely linked with reduced quality of life and fatigue, especially their physical components. Trials are warranted to test whether optimized nutrition support can halt further aggravation during treatment.

BACKGROUND:Pancreatic main duct dilation (PMDD) may indicate an increased risk of developing pancreatic cancer. Little is known about the prevalence and natural course of PMDD in the general population. Therefore, this study aimed to analyse PMDD using magnet resonance imaging (MRI). METHODS:Longitudinal MRI combined with magnetic resonance cholangiopancreatography was performed between 2008 and 2021 as part of the prospective population-based Study of Health in Pomerania (SHIP), with 2,2 ± 0,6 MRI per participant on average performed within an average of 10,8 ± 1,2 yrs. PMDD was defined as ≥ 5 mm, and was correlated with clinical and epidemiological data. RESULTS:The prevalence of PMDD was 81/2985 individuals (2.7%). The mean age of these was 55.1 ± 13.2 yrs. Cumulative 5 yr-incidence of newly developed PMDD was 1.1% (22/1935) and 3.0% (15/496) after 10 yrs. Poisson regression analysis revealed strong associated factors of PMDD: active smoking (PR 2.93), diabetes (PR 2.58) and frequent alcohol abuse (PR 1.78) After a median follow-up period of 4.5 years, pancreatic cancer and chronic pancreatitis were diagnosed more frequently in the PMDD group: 2/81 (2.5%) vs. 24/2904 (0.8%) and 8/81 (9.9%) vs. 46/2904 (1.6%). Pancreatic cancer-specific survival was lower in cases of PMDD (HR = 4.96 (95% CI 1.31-18.84)). CONCLUSION:A PMDD ≥5 mm is a frequent incidental MRI finding in the general population (2.7%). The risk of malignant transformation was higher with PMDD (2.5%) than without (0.8%). Chronic pancreatitis was diagnosed four times as often than pancreatic cancer in follow-up.

Die hereditäre Pankreatitis ist eine seltene Erkrankung. Sie ist v. a. auf Mutationen im kationischen Trypsinogen-Gen (PRSS1 [„serine protease 1“]) zurückzuführen, die autosomal-dominant und mit hoher Penetranz vererbt werden. Zusätzlich prädisponieren zahlreiche Varianten in Genen, die für verschiedene in Azinuszellen und duktalen Zellen exprimierte Proteine kodieren, entweder in Kombination mit weiteren genetischen Faktoren, anatomischen Besonderheiten oder bestimmten Umweltfaktoren für eine chronische Pankreatitis (CP). Man nimmt an, dass bei der idiopathischen CP zu einem erheblichen Anteil Varianten von Risikogenen für eine Pankreatitis zugrunde liegen. Zu den wesentlichen zu einer Pankreatitis führenden pathophysiologischen Mechanismen zählen eine gesteigerte Verdauungsenzymaktivierung infolge einer Dysbalance zwischen den Enzymen und ihren Inhibitoren, ein erhöhter ER(endoplasmatisches Retikulum)-Stress und eine gestörte Bikarbonatsekretion. Eine genetische Testung sollte bei familiärer Häufung einer Pankreatitis und nicht geklärter akuter rekurrierender Pankreatitis oder CP angestrebt werden. Eine adäquate genetische Beratung ist bei diesen Individuen essenziell.

Acute pancreatitis (AP) is characterised by self-digestion of the pancreas by its own proteases. This pathophysiological initiating event in AP occurs inside pancreatic acinar cells where intrapancreatic trypsinogen becomes prematurely activated by cathepsin B (CTSB), and induces the digestive protease cascade, while cathepsin L (CTSL) degrades trypsin and trypsinogen and therefore prevents the development of AP. These proteases are located in the secretory compartment of acinar cells together with cystatin C (CST3), an endogenous inhibitor of CTSB and CTSL. The results are based on detailed biochemical analysis, site-directed mutagenesis and molecular dynamics simulations in combination with an experimental disease model of AP using CST3 deficient mice. This identifies that CST3 is a critical regulator of CTSB and CTSL activity during AP. CST3 deficient mice show a higher intracellular CTSB activity resulting in elevated trypsinogen activation accompanied by an increased disease severity. This reveals that CST3 can be cleaved by trypsin disabling the inhibition of CTSB, but not of CTSL. Furthermore, dimerised CST3 enhances the CTSB activity by binding to an allosteric pocket specific to the CTSB structure. CST3 shifts from an inhibitor to an activator of CTSB and therefore fuels the intrapancreatic protease cascade during the onset of AP.

BACKGROUND & AIMS:Fatigue is a prevalent and debilitating symptom in patients with liver cirrhosis (LC), characterized by persistent exhaustion that impairs both physical and mental function. Despite its significant impact fatigue is often overlooked in clinical practice due to its complex and subjective nature. Emerging evidence suggests central mechanisms underlying fatigue in LC, with potential links to malnutrition and sarcopenia. This study aimed to determine the prevalence of fatigue in LC patients, investigate its associations with malnutrition and sarcopenia, and identify independent indicators to aid in recognizing high-risk individuals. Additionally, the study explored the trajectory of fatigue in a structured nutritional intervention in malnourished LC patients. METHODS:In a multicentric cross-sectional study, 91 LC patients and 92 matched healthy controls were recruited. Analysis focused on 56 LC patients, assessing both central and peripheral fatigue with the Fatigue Severity Scale (FSS), along with anxiety and depression (Hospital Anxiety and Depression Scale, HADS), and loneliness (De Jong Gierveld Scale). Body composition, malnutrition, and sarcopenia were evaluated using bioelectrical impedance, Global Leadership Initiative on Malnutrition (GLIM) and European Working Group on Sarcopenia in Older People (EWGSOP) II criteria. Laboratory parameters and waist circumference as indicator for ascites were assessed. Functional status was measured via handgrip strength (Jamar Dynamometer) and gait speed, and physical activity levels were assessed using the International Physical Activity Questionnaire short form (IPAQ SF). Dietary intake was evaluated with a validated Food Frequency Questionnaire (FFQ). The course of fatigue was investigated in a single-arm exploratory, intensified three-month nutritional intervention study with a 6-month follow-up in malnourished LC patients. RESULTS:Fatigue, affecting 68 % of LC patients, was more common than in controls and linked to both central and peripheral symptoms. LC patients also experienced higher rates of anxiety, depression, and mild loneliness. While 59 % had malnutrition and 23 % sarcopenia, neither were related to fatigue, nor anemia markers like hemoglobin or hematocrit. Fatigue was linked to increased use of proton pump inhibitors and antibiotics. Fatigue severity was correlated with increased anxiety, depression, loneliness, increased waist circumference, and lower gait speed and physical activity. Regression analysis showed increased waist circumference and reduced gait speed as independent predictors of fatigue. Nutritional intervention in malnourished LC patients led to improvements in fatigue, anxiety, and depression. CONCLUSION:Ascites and gait speed are practical clinical indicators of fatigue in LC patients. Nutritional therapy shows promise in alleviating fatigue and malnutrition in LC patients, offering a potential therapeutic approach. GERMAN REGISTER OF CLINICAL STUDIES:DRKS00021124, DRKS00021181.

INTRODUCTION:The exocrine pancreas is an important determinant of the intestinal microbiome composition and stability. Although chronic pancreatitis (CP) is known to severely affect the bacterial community, its impact on the intestinal mycobiome is currently unknown. METHODS:A total of 93 patients with clinical and imaging evidence of CP were prospectively recruited and compared with 2 equally sized matched control cohorts. One control group was matched for age, sex, body mass index, and smoking (Con-1), and the other additionally for exocrine pancreatic function (stool elastase) and diabetes (Con-2). Fecal samples were collected from all 279 individuals to determine the fecal mycobiome by internal transcribed spacer 2 sequencing. RESULTS:In CP patients, fungal reads were increased (3.7-fold and 2.0-fold) as compared with Con-1 and Con-2. In comparison with Con-1, CP patients demonstrated higher total abundance of Candida (4.5-fold, q = 0.009) and higher mean relative abundance (11.4% vs 1.0%, q = 0.014) and presence (25.8% vs 9.7%, q = 0.025) of Nakaseomyces . In contrast to Con-2, CP patients showed higher Candida total abundance (1.9-fold, P = 0.016) which was, however, not significant after correction for multiple testing ( q = 0.056). DISCUSSION:Not only the microbiome but also the mycobiome in CP patients is characterized by distinct changes, with higher abundances of Candida or Nakaseomyces . Exocrine pancreatic dysfunction in CP patients likely contributes to this observation. This may result in increased rates of fungal infections, chronic inflammation, and could be contributing to the development of pancreatic cancer.

Background The investigation of prevalence trends of metabolic cardiovascular risk factors is important for appropriate planning of future health programs aiming to prevent cardiovascular morbidity and mortality. In a previous study, we demonstrated an increase in the prevalence of type 2 diabetes (T2D) between 2000 and 2010 in Northeast Germany. The purpose of this study is to investigate prevalence trends of T2D treatment, dyslipidemia and hepatic steatosis in Northeast Germany. Methods The baseline examinations of the first Study of Health in Pomerania (SHIP) project were carried out from 1997 to 2001 (SHIP-START-0, 4308 subjects). A second, independent random sample of the same region was enrolled between 2008 and 2012 (SHIP-TREND-0, 4420 subjects). All data were standardized with post-stratification weighting derived from the adult population of the German federal state of Mecklenburg-West Pomerania. Results The prevalence of metformin intake increased from 2.1% to 4.1% and insulin use from 2.0% to 2.8%. While the prevalence of statin intake increased from 6.8% to 12.2%, the prevalence of dyslipidemia decreased slightly from 49.0% in SHIP-START-0 to 45.5% in SHIP-TREND-0. The prevalence of hepatic steatosis increased from 29.7% to 37.3%. This increase was most prominently observed in women and younger age groups. Conclusions T2D, dyslipidemia and hepatic steatosis are common and increasing health problems among adults in Northeast Germany. Reassuring healthy diet and controlling obesity may result in prevention of above-mentioned health problems.

An uncontrolled activity of neutrophil serine proteases (NSPs) contributes to inflammatory diseases. Cathepsin C (CatC) is known to activate NSPs during neutrophilic differentiation and represents a promising pharmacological target in NSP-mediated diseases. In humans, Papillon-Lefèvre syndrome (PLS) patients have mutations in theirCTSC gene, resulting in the complete absence of CatC activity. Despite this, low residual NSP activities are detected in PLS neutrophils (<10% vs healthy individuals), suggesting the involvement of CatC-independent proteolytic pathway(s) in the activation of proNSPs. This prompted us to characterize CatC-independent NSP activation pathways by blocking proCatC maturation. In this study, we show that inhibition of intracellular CatS almost completely blocked CatC maturation in human promyeloid HL-60 cells. Despite this, NSP activation was not significantly reduced, confirming the presence of a CatC-independent activation pathway involving a CatC-like protease that we termed NSPs-AAP-1. Similarly, when human CD34+ progenitor cells were treated with CatS inhibitors during neutrophilic differentiation in vitro, CatC activity was nearly abrogated but ∼30% NSP activities remained, further supporting the existence of NSPs-AAP-1. Our data indicate that NSPs-AAP-1 is a cysteine protease that is inhibited by reversible nitrile compounds designed for CatC inhibition. We further established a proof of concept for the indirect, although incomplete, inhibition of NSPs by pharmacological targeting of CatC maturation using CatS inhibitors. This emphasizes the potential of CatS as a therapeutic target for inflammatory diseases. Thus, preventing proNSP maturation using a CatS inhibitor, alone or in combination with a CatC/NSPs-AAP-1 inhibitor, represents a promising approach to efficiently control the extent of tissue injury in neutrophil-mediated inflammatory diseases.

Abstract Background Antimicrobial autoantigenic glycoprotein 2 (GP2) is an important component of the innate immune system which originates from the exocrine pancreas as well as from the small intestines. The relationship of GP2 with the intestinal microbiome as well as the systemic implications of increased fecal GP2 levels are, however, still unclear. Therefore, fecal samples from 2,812 individuals of the Study of Health in Pomerania (SHIP) were collected to determine GP2 levels (enzyme-linked immunosorbent assay) and gut microbiota profiles (16 S rRNA gene sequencing). These data were correlated and associated with highly standardised and comprehensive phenotypic data of the study participants. Results Fecal GP2 levels were increased in individuals with higher body mass index and smokers, whereas lower levels were found in case of preserved exocrine pancreatic function, female sex or a healthier diet. Moreover, higher GP2 levels were associated with increased serum levels of high-sensitivity C-reactive protein, loss of gut microbial diversity and an increase of potentially detrimental bacteria (Streptococcus, Haemophilus, Clostridium XIVa, or Collinsella). At the same time, predicted microbial pathways for the biosynthesis of beneficial short-chain fatty acids or lactic acid were depleted in individuals with high fecal GP2. Of note, GP2 exhibited a stronger association to overall microbiome variation than calprotectin. Conclusion Fecal GP2 is a biomarker of gut microbiota dysbiosis and associated with increased systemic inflammation. The intestines may be more important as origin for GP2 than pancreatic acinar cells. Future studies need to investigate the potential clinical value in disease specific patient cohorts.

Cathepsin C (CatC, syn. Dipeptidyl peptidase I) is a lysosomal cysteine proteinase expressed in several tissues including inflammatory cells. This enzyme is important for maintaining multiple cellular functions and for processing immune cell-derived proteases. While mutations in the CatC gene were reported in Papillon-Lefèvre syndrome, a rare autosomal recessive disorder featuring hyperkeratosis and periodontitis, evidence from clinical and preclinical studies points toward pro-inflammatory effects of CatC in various disease processes that are mainly mediated by the activation of neutrophil serine proteinases. Moreover, tumor-promoting effects were ascribed to CatC. The aim of this review is to highlight current knowledge of the CatC as a potential therapeutic target in inflammatory disorders.

BackgroundDevelopment of pancreatic necroses or pseudocysts are typical complications of pancreatitis and may require endoscopic drainage therapy using metal or plastic stents. Microbial infection of these lesions poses a major challenge. So far, the composition and significance of the microbial colonization on drainage stents are largely unknown although it may impact outcomes during endoscopic drainage therapy.MethodsA total of 26 stents used for drainage of pancreatic lesions were retrieved and the stent microbiome was determined by 16S rRNA gene sequencing. Additional analysis included comparison of the stent microbiome to the intracavitary necrosis microbiome as well as scanning electron microscopy (SEM) and micro-computed tomography (μCT) imaging of selected metal or plastic stents.ResultsThe stent microbiome comprises a large proportion of opportunistic enteric pathogens such as Enterococcus (14.4%) or Escherichia (6.1%) as well as oral bacteria like Streptococcus (13.1%). Increased levels of opportunistic enteric pathogens were associated with a prolonged hospital stay (r = 0.77, p = 3e−06) and the occurrence of adverse events during drainage therapy (p = 0.011). Higher levels of oral bacteria were associated (r = −0.62, p = 8e-04) with shorter durations of inpatient treatment. SEM and μCT investigations revealed complex biofilm networks on the stent surface.ConclusionThe composition of the stent microbiome is associated with prolonged hospital stays and adverse events during endoscopic drainage therapy, highlighting the need for effective infection control to improve patient outcomes. In addition to systemic antibiotic therapy, antimicrobial stent coatings could be a conceivable option to influence the stent microbiome and possibly enhance control of the necrotic microflora.

The exocrine pancreas is the main source of digestive enzymes which are released from secretory vesicles of acinar cells into the small intestine. Enzymes, including amylases, proteases and lipases, degrade the ingested food and thus determine the nutritional substrate for the gut microbiota. Acute (AP) and chronic pancreatitis (CP) are associated with a transitional or progressive exocrine pancreatic dysfunction, we analysed in the present study how an experimental induction of pancreatitis in mouse models affects the colonic and duodenal microbiome composition. Evaluation by 16 S rRNA gene sequencing revealed specific microbiome changes in colonic as well as in duodenal samples in different models of AP and CP. Mild acute pancreatitis, which is associated with a transient impairment of pancreatic secretion showed only minor changes in microbial composition, comparable to the ones seen in progressive dysfunctional mouse models of CP. The strongest changes were observed in a mouse model of severe AP, which suggest a direct effect of the immune response on gut microbiome in addition to a pancreatic dysfunction. Our data indicate that highly dysbiotic microbiome changes during pancreatitis are more associated with the inflammatory reaction than with a disturbed pancreatic secretion.

Malnutrition is a common complication of chronic pancreatitis (CP) and liver cirrhosis (LC). Inadequate food intake is considered a relevant driver of malnutrition in both entities. However, the contribution of habitual diet to impaired nutritional status is unclear. In a prospective, multicenter cross-sectional study, we recruited patients with confirmed CP or LC and healthy volunteers as a control group. Malnutrition was diagnosed according to the Global Leadership Initiative on Malnutrition criteria. We comprehensively investigated habitual dietary intake on nutrient, food group, and dietary pattern level applying two validated food frequency questionnaires. We included 144 patients (CP: n = 66; LC: n = 78) and 94 control subjects. Malnutrition was prevalent in 64% and 62% of patients with CP or LC, respectively. In both CP and LC, despite slightly altered food group consumption in malnourished and non-malnourished patients there were no differences in energy or nutrient intake as well as dietary quality. Compared to controls patients showed distinct dietary food group habits. Patients consumed less alcohol but also lower quantities of fruits and vegetables as well as whole grain products (p < 0.001, respectively). Nevertheless, overall dietary quality was comparable between patients and healthy controls. Nutritional status in CP and LC patients is rather related to disease than habitual dietary intake supporting the relevance of other etiologic factors for malnutrition such as malassimilation or chronic inflammation. Despite distinct disease-related differences, overall dietary quality in patients with CP or LC was comparable to healthy subjects, which suggests susceptibility to dietary counselling and the benefits of nutrition therapy in these entities.

Acetaminophen (APAP) overdosing is a major cause of acute liver failure worldwide and an established model for drug-induced acute liver injury (ALI). While studying gene expression during murine APAP-induced ALI by 3'mRNA sequencing (massive analysis of cDNA ends, MACE), we observed splenic mRNA accumulation encoding for the neutrophil serine proteases cathepsin G, neutrophil elastase, and proteinase-3 - all are hierarchically activated by cathepsin C (CtsC). This, along with increased serum levels of these proteases in diseased mice, concurs with the established phenomenon of myeloid cell mobilization during APAP intoxication. Objective: In order to functionally characterize CtsC in murine APAP-induced ALI, effects of its genetic or pharmacological inhibition were investigated. Methods and Results: We report on substantially reduced APAP toxicity in CtsC deficient mice. Alleviation of disease was likewise observed by treating mice with the CtsC inhibitor AZD7986, both in short-term prophylactic and therapeutic protocols. This latter observation indicates a mode of action beyond inhibition of granule-associated serine proteases. Protection in CtsC knockout or AZD7986-treated wildtype mice was unrelated to APAP metabolization but, as revealed by MACE, realtime PCR, or ELISA, associated with impaired expression of inflammatory genes with proven pathogenic roles in ALI. Genes consistently downregulated in protocols tested herein included cxcl2, mmp9, and angpt2. Moreover, ptpn22, a positive regulator of the toll-like receptor/interferon-axis, was reduced by targeting CtsC. Conclusions: This work suggests CtsC as promising therapeutic target for the treatment of ALI, among others paradigmatic APAP-induced ALI. Being also currently evaluated in phase III clinical trials for bronchiectasis, successful application of AZD7986 in experimental APAP intoxication emphasizes the translational potential of this latter therapeutic approach.