Pancreatic endosonographic findings and clinical correlation in Crohn's disease

Fusobacterium nucleatum promotes the development of acute liver failure by inhibiting the NAD+ salvage metabolic pathway

BACKGROUND

Acute liver failure (ALF) patients are often accompanied by severe energy metabolism abnormalities and intestinal microecological imbalance. The intestinal mucosal barrier is severely damaged. Intestinal endotoxin can induce intestinal endotoxemia through the "Gut-Liver axis". More and more evidence shows that members of the gut microbiota, especially Fusobacterium nucleatum (F. nucleatum), are related to inflammatory bowel disease, but whether F. nucleatum is involved in the development of ALF and whether it affects the liver energy metabolism is unclear.

METHODS

This study first detected the abundance of F. nucleatum and its effect on ALF disease, and explored whether F. nucleatum aggravated liver inflammation in vitro and in vivo.

RESULTS

Our data showed that liver tissues of ALF patients contained different abundances of F. nucleatum, which were related to the degree of liver inflammation. In addition, we found that F. nucleatum infection affected the energy metabolism of the liver during the development of ALF, inhibited the synthesis pathway of nicotinamide adenine dinucleotide (NAD⁺)'s salvage metabolism, and promoted inflammatory damage in the liver. In terms of mechanism, F. nucleatum inhibited NAD⁺ and the NAD⁺-dependent SIRT1/AMPK signaling pathway, and promoted liver damage of ALF.

CONCLUSIONS

Fusobacterium nucleatum coordinates a molecular network including NAD⁺ and SIRT1 to control the progress of ALF. Detection and targeting of F. nucleatum and its related pathways may provide valuable insights for the treatment of ALF.

Fusobacterium nucleatum Activates Endoplasmic Reticulum Stress to Promote Crohn's Disease Development via the Upregulation of CARD3 Expression

There is increasing evidence that members of the gut microbiota, especially Fusobacterium nucleatum (F. nucleatum), are associated with Crohn’s disease (CD), but the specific mechanism by which F. nucleatum promotes CD development is unclear. Here, we first examined the abundance of F. nucleatum and its effects on CD disease activity and explored whether F. nucleatum aggravated intestinal inflammation and promoted intestinal mucosal barrier damage in vitro and in vivo. Our data showed that F. nucleatum was enriched in 41.21% of CD tissues from patients and was correlated with the clinical course, clinical activity, and refractory behavior of CD (P < 0.05). In addition, we found that F. nucleatum infection is involved in activating the endoplasmic reticulum stress (ERS) pathway during CD development to promote intestinal mucosal barrier destruction. Mechanistically, F. nucleatum targeted caspase activation and recruitment domain 3 (CARD3) to activate the ERS pathway and promote F. nucleatum-mediated mucosal barrier damage in vivo and in vitro. Thus, F. nucleatum coordinates a molecular network involving CARD3 and ERS to control the CD process. Measuring and targeting F. nucleatum and its associated pathways will provide valuable insight into the prevention and treatment of CD.

Pancreatic exocrine insufficiency and Crohn's disease

BACKGROUND

According to the European evidence-based consensus, published by European Crohn's and Colitis Organization (ECCO), diseases of the pancreas are included as extra-intestinal manifestations in IBD in the forms of acute pancreatitis (AP), chronic pancreatitis (CP), autoimmune pancreatitis (AIP), pancreatic duct abnormalities and pancreatic exocrine insufficiency (PEI). Presence of pancreatic autoantibodies directed against the exocrine of the pancreas has been reported in about one-third of CD. However, association between CD and PEI is not fully elucidated.

METHODS

Patients with a diagnosis of CD were recruited at the Department for Digestive Diseases at Karolinska University Hospital in Stockholm, Sweden. Demographic, clinical and laboratory data were analyzed. Fecal elastase-1 (FE-1) measurements were performed using the enzyme-linked immunosorbent assay (ELISA) method.

RESULTS

There were 20 patients included in the study, 13 (65%) males and 7 (35%) females, mean age 48.3±1.4 years (range 29-67 years). Mean duration of CD was 15.7±2.1 years (range 1-40 years). There were 11 (55%) patients without history of bowel surgery and 9 (45%) patients after ileocecal resection. FE-1 test was normal in all patients, among them 15 (75%) patients with the values of FE-1>500.

CONCLUSIONS

Fecal elastase-1 level was normal in all patients with CD strongly indicated absence of PEI in this group of patients.