Genetic and environmental factors drive personalized medicine for Crohn's disease

Oral Macrocystis pyrifera Fucoidan Administration Exhibits Anti-Inflammatory and Antioxidant Properties and Improves DSS-Induced Colitis in C57BL/6J Mice

Inflammatory bowel disease (IBD) is a complex and multifactorial disorder characterised by relapsing and remitting inflammation of the intestinal tract. Oxidative stress (OS) is the result of an imbalance between production and accumulation of reactive oxygen species (ROS), which has been associated with inflammatory responses and implicated in the exacerbation of IBD. Fucoidan, a sulfated polysaccharide from brown seaweed, is a well-known anti-inflammatory agent and emerging evidence indicates that fucoidan extracts from Macrocystis pyrifera (MPF and DP-MPF) may also modulate oxidative stress. This study investigated the impact of fucoidan extracts, MPF and DP-MPF in a dextran sodium sulphate (DSS)-induced mouse model of acute colitis. 3% DSS was administered in C57BL/6J male mice over a period of 7 days, and MPF and DP-MPF were co-administered orally at a dose of 400 mg/kg body weight. Our results indicated that MPF and DP-MPF significantly prevented body weight loss, improved the disease activity index (DAI), restored colon lengths, reduced the wet colon weight, reduced spleen enlargement, and improved the overall histopathological score. Consistent with the reported anti-inflammatory functions, fucoidan extracts, MPF and DP-MPF significantly reduced the colonic levels of myeloperoxidase (MPO), nitric oxide (NO), malondialdehyde (MDA) and increased the levels of antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT). In addition, MPF and DP-MPF significantly inhibited levels of pro-inflammatory cytokines in colon-derived tissues. Collectively, our results indicate that MPF and DP-MPF exhibited anti-inflammatory and antioxidant effects representing a promising therapeutic strategy for the cure of IBD.

The roles and functions of Paneth cells in Crohn's disease: A critical review

Paneth cells (PCs) are located at the base of small intestinal crypts and secrete the α‐defensins, human α‐defensin 5 (HD‐5) and human α‐defensin 6 (HD‐6) in response to bacterial, cholinergic and other stimuli. The α‐defensins are broad‐spectrum microbicides that play critical roles in controlling gut microbiota and maintaining intestinal homeostasis. Inflammatory bowel disease, including ulcerative colitis and Crohn's disease (CD), is a complicated autoimmune disorder. The pathogenesis of CD involves genetic factors, environmental factors and microflora. Surprisingly, with regard to genetic factors, many susceptible genes and pathogenic pathways of CD, including nucleotide‐binding oligomerization domain 2 (NOD2), autophagy‐related 16‐like 1 (ATG16L1), immunity‐related guanosine triphosphatase family M (IRGM), wingless‐related integration site (Wnt), leucine‐rich repeat kinase 2 (LRRK2), histone deacetylases (HDACs), caspase‐8 (Casp8) and X‐box‐binding protein‐1 (XBP1), are relevant to PCs. As the underlying mechanisms are being unravelled, PCs are identified as the central element of CD pathogenesis, integrating factors among microbiota, intestinal epithelial barrier dysfunction and the immune system. In the present review, we demonstrate how these genes and pathways regulate CD pathogenesis via their action on PCs and what treatment modalities can be applied to deal with these PC‐mediated pathogenic processes.

Development of a clinical model to predict secondary non-response of infliximab treatment in Crohn's disease

PURPOSE

Secondary non-response to infliximab (IFX) in patients with Crohn's disease (CD) is so common that prediction of non-response is required to adopt the optimal therapy for an individual patient.

METHODS

The clinical model was constructed in a training cohort. Clinical features, serological parameters, and genetic biomarkers at week 14 IFX therapy were obtained as predictors. Secondary non-response was defined at week 54. Univariate analysis was first performed to eliminate irrelevant predictors with non-response. Then, a logistic regression model was developed by using predictors with P < 0.1 in a univariate analysis. Finally, the model was validated with reference to its discrimination, calibration, and decision curve analysis (DCA).

RESULTS

In a univariate analysis, erythrocyte sedimentation rate (ESR), the previous surgery, disease location, C-reactive protein (CRP), and TNFRSF1B (676 T>G) were found associated with secondary non-response to IFX. Logistic regression analysis with stepwise backward selection P < 0.05 then identified that ESR, the previous surgery, CRP, and TNFRSF1B (676 T>G) could serve as independent predictors, and a clinical model was developed based on the above predictors. Model 2 with TNFRSF1B (676 T>G) incorporated demonstrated more satisfactory discrimination (P = 0.029), better calibration (U P2 > 0.05), and higher clinical value in the validation cohort.

CONCLUSIONS

The study presents a model to predict non-response to IFX in CD, which incorporates previous surgery, ESR, CRP, and TNFRSF1B (676 T>G). This model can be used to help clinicians adjust the therapeutic strategy and CD patients avoid unnecessary exposure to IFX.

Introducing GATA3 as a prominent player in Crohn's disease

AIM

This study was aimed at gene assessment of Crohn's disease (CD) through protein-protein interaction (PPI) network analysis to find crucial genes.

BACKGROUND

CD is a major subtype of inflammatory bowel diseases (IBD), which affects gastrointestinal tract. PPI network analysis is a suitable tool to clarify a critical gene as a drug target or diagnostic biomarker for these types of diseases.

METHODS

Gene expression profile GSE126124 of 20 CD patients and 20 healthy controls was obtained from the Gene Expression Omnibus (GEO) database. RNA profile of peripheral blood mononuclear cells (PBMCs) and colon biopsy samples of the studied groups was investigated. Crucial genes were selected and analyzed via the PPI network by Cytoscape software. Gene ontology enrichment for the hubs, bottlenecks, and hub-bottlenecks was performed via CluGO plugin of Cytoscape software.

RESULTS

Eighty-one differentially expressed genes (DEGs) among 250 initial DEGs were highlighted as significant by FC>2 and p-value ≤ 0.05, and 69 significant DEGs were used for PPI network construction. The network was characterized by poor connections, so 20 top neighbors were added to form a scale-free network. The main connected component included 39 query DEGs and 20 added first neighbors. Three clusters of biological processes associated with crucial genes were identified and discussed.

CONCLUSION

The results of this study indicated that GATA3 has a key role in CD pathogenesis and could be a possible drug target or diagnostic biomarker for Crohn's disease.