Role of conventional therapies in the era of biological treatment in Crohn’s disease

Hyperoxidation of ether-linked phospholipids accelerates neutrophil extracellular trap formation

Because neutrophil extracellular trap (NET) formation is involved in the pathology of a wide variety of diseases, NET-regulating compounds are expected to be useful for the therapies of these diseases. In this study, we identified sulfasalazine (SSZ) as a potent enhancer of NET formation both in vitro and in vivo. Although SSZ did not increase the amount of ROS generated, it accelerated the generation of ether-linked oxidized phospholipids, such as PE (18;1e/15-HETE) and PC (16;0e/13-HODE). Trolox, but not 2-ME, effectively suppressed lipid oxidation and NET formation that were induced by SSZ. SSZ is known as a potent inducer of ferroptosis in cancer cells by inhibiting xCT, a component of the cystine transporter. However, we found that SSZ accelerated NET formation in an xCT-independent manner. Structure-activity relationship studies revealed that the sulfapyridine moiety of SSZ plays a central role in enhancing NET formation. Furthermore, we found that two additional sulfonamide and sulfone derivatives possess NET-inducing activity by accelerating lipid oxidation. These results indicate that the hyperoxidation of ether-linked phospholipids is a key mechanism for accelerating NET formation.

Coagulation state in patients with Crohn's disease: the effect of infliximab therapy

BACKGROUND

Growing evidence has shown that coagulation processes play an important role in disease pathogenesis and/or disease progression in patients with inflammatory bowel disease. However, no study has ever focused on the possible influence of infliximab (IFX) therapy on the coagulation status in patients with Crohn's disease (CD).

OBJECTIVE

To investigate the difference in the coagulation biomarkers between the CD patients and the control participants, and evaluate the impact of IFX usage on the coagulation status of CD patients.

PATIENTS AND METHODS

A retrospective study that included a case-control study and a self-control study was designed. The medical records of CD patients and control participants were evaluated according to the inclusion and exclusion criteria. The results of laboratory tests including blood routine, coagulation, D-dimer, C-reactive protein, and erythrocyte sedimentation rate were retrieved to assess the coagulation state.

RESULTS

In the case-control study, almost all the parameters showed a statistically significant difference between the CD patients and the control participants, except for activated partial thromboplastin time and thrombin time (the P value ranged from 0.000 to 0.002). Most of the values of the parameters reverted to normal over time during IFX therapy in the self-control study. Moreover, the fibrinogen concentration decreased obviously after IFX infusion (P=0.000) and the D-dimer concentration also decreased obviously by about half of the start value after IFX usage (P=0.018).

CONCLUSION

IFX therapy could ameliorate the hypercoagulable state in patients with CD.

Select a suitable treatment strategy for Crohn's disease: step-up or top-down

Crohn's Disease (CD) is a chronic immune-mediated disorder with progressive and destructive course. Current guidelines on the treatment strategy still recommend a step-up approach with sequential prescription of corticosteroids and immunosuppressives. However, mounting evidences manifested that top-down therapy with early administration of anti-TNF or combination of immunosuppressives can achieve more rapid and higher rate of mucosal healing and has the potential of modifying the natural course of disease. Therefore, who is suitable to accept and when to start anti-TNF therapy have attracted the attention of gastroenterologists. And what benefit/risk can be expected from the two strategies should be carefully taken into account by clinicians. Age stratification, special patients, disease location and extension, genetic and serologic testing are predictors of disease progression and complication and thus guide a personalized treatment approach in CD. A definition of early CD has been proposed to select an algorithm for treatment of moderate-to-severe CD with a suitable strategy. To date mucosal healing has been widely used, the Lémann score, which assesses the extent and severity of bowel damage at a specific time-point and over time, and is a new disability index for patients with CD, will be considered as a new endpoint for future studies of treatment strategies. Besides medicines of the two strategies, surgery, vaccine, Leukocytapheresis and stem cell therapy are all effective therapeutic approaches which lead to another thinking about what should they be putted in the conditional pyramid. However, we are trying to answer these questions.

Colicin-like bacteriocins as novel therapeutic agents for the treatment of chronic biofilm-mediated infection

The emergence of pan-resistant strains of Gram-negative pathogens and the ability of many bacteria to form multidrug-resistant biofilms during chronic infection poses the grave threat of bacterial infections that are truly untreatable with our current armoury of antibiotics. Despite obvious clinical need, few new antibiotics have entered clinical practice in recent years. For 'difficult to treat' Gram-negative bacteria such as Pseudomonas aeruginosa and Escherichia coli, where the presence of outer membrane and multidrug-efflux pumps severely limit the effectiveness of whole classes of antibiotics, the need is particularly pressing. An alternative approach to antimicrobial treatment is to use the well-characterized species-specific colicin-like bacteriocins which are produced by a wide range of Gram-negative bacteria, including Pseudomonas aeruginosa and Escherichia coli. Our current work on colicin-like bacteriocins aims to determine whether these potent antimicrobial agents are effective at killing bacteria growing in the biofilm state and during infection.

Intestinal alkaline phosphatase in the colonic mucosa of children with inflammatory bowel disease

AIM: To investigate intestinal alkaline phosphatase (iAP) in the intestinal mucosa of children with inflammatory bowel disease (IBD).

METHODS: Colonic biopsy samples were taken from 15 newly diagnosed IBD patients and from 10 healthy controls. In IBD patients, specimens were obtained both from inflamed and non-inflamed areas. The iAP mRNA and protein expression was determined by reverse transcription-polymerase chain reaction and Western blotting analysis, respectively. Tissue localization of iAP and Toll-like receptor (TLR) 4 was investigated by immunofluorescent staining.

RESULTS: The iAP protein level in the inflamed mucosa of children with Crohn’s disease (CD) and ulcerative colitis (UC) was significantly decreased when compared with controls (both P < 0.05). Similarly, we found a significantly decreased level of iAP protein in the inflamed mucosa in CD compared with non-inflamed mucosa in CD (P < 0.05). In addition, the iAP protein level in inflamed colonic mucosa in patients with UC was decreased compared with non-inflamed mucosa in patients with CD (P < 0.05). iAP protein levels in the non-inflamed mucosa of patients with CD were similar to controls. iAP mRNA expression in inflamed colonic mucosa of children with CD and UC was not significantly different from that in non-inflamed colonic mucosa with CD. Expression of iAP mRNA in patients with non-inflamed mucosa and in controls were similar. Co-localization of iAP with TLR4 showed intense staining with a dotted-like pattern. iAP was present in the inflamed and non-inflamed mucosa of patients with CD, UC, and in control biopsy specimens, irrespective of whether it was present in the terminal ileum or in the colon. However, the fluorescent signal of TLR4 was more pronounced in the colon compared with the terminal ileum in all groups studied.

CONCLUSION: Lower than normal iAP protein levels in inflamed mucosa of IBD patients may indicate a role for iAP in inflammatory lesions in IBD. Based on our results, administration of exogenous iAP enzyme to patients with the active form of IBD may be a therapeutic option.