Follow up on atopy and the gastrointestinal tract - a review of a common association 2018

Network pharmacology integrated with molecular docking and molecular dynamics simulations to explore the mechanism of Shaoyao Gancao Tang in the treatment of asthma and irritable bowel syndrome

BACKGROUND

Numerous studies have demonstrated a correlation between asthma and irritable bowel syndrome (IBS). The Chinese herbal compound Shaoyao Gancao Tang (SYGCT) has been found to have therapeutic effects on both asthma and IBS, but the underlying mechanisms are not yet fully understood. This study aims to explore the key components, key targets, and potential mechanisms of SYGCT in treating asthma with IBS by using network pharmacology, molecular docking techniques and molecular dynamics simulation.

METHODS

The major chemical components and potential target genes of SYGCT were screened by bioinformatics. The key targets of Asthma-IBS comorbidity were identified based on network modules. The intersection of the drug targets and disease targets was identified as the potential targets of SYGCT in treating asthma-IBS. Gene Ontology functional annotation and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis were performed to identify the biological processes and signaling pathways involved in these potential targets. A protein-protein interaction network was constructed to identify hub targets, while a drug-compound-target topological network was built to screen key compounds. Molecular docking was used to verify the affinity between the hub targets and key compounds. Molecular dynamics analysis was utilized to assess the binding stability of these interactions.

RESULTS

Network pharmacology analysis revealed that the therapeutic effect of SYGCT on asthma-IBS involved multiple biological processes and signaling pathways. It may exert therapeutic effects primarily through signaling pathways such as IL-17, TNF, and Th17 cell differentiation. The possible targets of SYGCT in the treatment of asthma-IBS could be IL6, TNF, JUN, PTGS2, STAT3, IL1B, CASP3, NFKBIA, IL10, and PPARG. Molecular docking verification showed that the predicted targets had good binding affinity with the compounds, among which PTGS2, CASP3, and PPARG had higher binding energy. Molecular dynamics simulation revealed that PTGS2, CASP3, and PPARG proteins had good stability and high binding strength with the compounds 2-[(3R)-8,8-dimethyl-3,4-dihydro-2H-pyrano[6,5-f]chromen-3-yl]-5-methoxyphenol and shinpterocarpin.

CONCLUSION

SYGCT plays a therapeutic role in asthma and IBS through multiple targets and pathways, providing a theoretical basis for explaining the mechanism and clinical application of SYGCT in treating different diseases with the same treatment in asthma and IBS.

Type 2 and type 17 effector cells are increased in the duodenal mucosa but not peripheral blood of patients with functional dyspepsia

Background

Functional dyspepsia is characterised by chronic symptoms of post-prandial distress or epigastric pain not associated with defined structural pathology. Increased peripheral gut-homing T cells have been previously identified in patients. To date, it is unknown if these T cells were antigen-experienced, or if a specific phenotype was associated with FD.

Objective

This study aimed to characterise T cell populations in the blood and duodenal mucosa of FD patients that may be implicated in disease pathophysiology.

Methods

We identified duodenal T cell populations from 23 controls and 49 Rome III FD patients by flow cytometry using a surface marker antibody panel. We also analysed T cell populations in peripheral blood from 37 controls and 61 patients. Where available, we examined the number of duodenal eosinophils in patients and controls.

Results

There was a shift in the duodenal T helper cell balance in FD patients compared to controls. For example, patients had increased duodenal mucosal Th2 populations in the effector (13.03 ± 16.11, 19.84 ± 15.51, p=0.038), central memory (23.75 ± 18.97, 37.52 ± 17.51, p=0.007) and effector memory (9.80±10.50 vs 20.53±14.15, p=0.001) populations. Th17 populations were also increased in the effector (31.74±24.73 vs 45.57±23.75, p=0.03) and effector memory (11.95±8.42 vs 18.44±15.63, p=0.027) subsets. Peripheral T cell populations were unchanged between FD and control.

Conclusion

Our findings identify an association between lymphocyte populations and FD, specifically a Th2 and Th17 signature in the duodenal mucosa. The presence of effector and memory cells suggest that the microinflammation in FD is antigen driven.

Physiological mechanisms of unexplained (functional) gastrointestinal disorders

Functional gastrointestinal disorders (FGIDs) encompass a range of complex conditions with similar clinical characteristics and no overt pathology. Recent recognition of sub-clinical pathologies in FGIDs, in conjunction with physiological and biochemical abnormalities including increased intestinal permeability, microbial profile alterations, differences in metabolites and extra-intestinal manifestations of disease, call into question the designation of these conditions as 'functional'. This is despite significant heterogeneity in both symptom profile and specifics of reported physiological abnormalities hampering efforts to determine defined mechanisms that drive onset and chronicity of symptoms. Instead, the literature demonstrates these conditions are disorders of homeostatic imbalance, with disruptions in both host and microbial function and metabolism. This imbalance is also associated with extraintestinal abnormalities including psychological comorbidities and fatigue that may be a consequence of gastrointestinal disruption. Given the exploitation of such abnormalities will be crucial for improved therapeutic selection, an enhanced understanding of the relationship between alterations in function of the gastrointestinal tract and the response of the immune system is of interest in identifying mechanisms that drive FGID onset and chronicity. Considerations for future research should include the role of sex hormones in regulating physiological functions and treatment responses in patients, as well as the importance of high-level phenotyping of clinical, immune, microbial and physiological parameters in study cohorts. There is opportunity to examine the functional contribution of the microbiota and associated metabolites as a source of mechanistic insight and targets for therapeutic modulation.

Epigenetic studies and pediatric research

The 2020 Annual Review Issue, "Preventing Disease in the 21st Century" was selected by the Editors-in-Chief of Pediatric Research to include a variety of disease entities that confront health-care practitioners entrusted to the care of infants and children. In keeping with this mandate, this article reviews the subject of epigenetics, which impacts pediatric research from bench to bedside. Epigenetic mechanisms exert their effects through the interaction of environment, various susceptibility genes, and immunologic development and include: (1) DNA methylation; (2) posttranslational modifications of histone proteins through acetylation and methylation, and (3) RNA-mediated gene silencing by microRNA (miRNA) regulation. The effects of epigenetics during fetal life and early periods of development are first reviewed together with clinical applications of cardiovascular and metabolic disorders in later life. The relationships of epigenetics to the allergic and autoimmune diseases and cancer are next reviewed. A specific focus of the article is directed to the recent recognition that many of these disorders are driven by aberrant immune responses in which immunoregulatory events are often poorly functioning and where through interventive epigenetic measures prevention may be possible by alterations in programming of DNA during fetal and early periods as well as in later life.