Comparison of Cytokine and Efflux Transporter Expression in Pediatric Versus Adult-onset Ulcerative Colitis

Inflammation Induces Changes in the Functional Expression of P-gp, BCRP, and MRP2: An Overview of Different Models and Consequences for Drug Disposition

The ATP-binding cassette (ABC) transporters play a key role in drug pharmacokinetics. These membrane transporters expressed within physiological barriers can be a source of pharmacokinetic variability. Changes in ABC transporter expression and functionality may consequently affect the disposition of substrate drugs, resulting in different drug exposure. Inflammation, present in several acute and chronic diseases, has been identified as a source of modulation in drug transporter expression leading to variability in drug response. Its regulation may be particularly dangerous for drugs with a narrow therapeutic index. In this context, numerous in vitro and in vivo models have shown up- or downregulation in the expression and functionality of ABC transporters under inflammatory conditions. Nevertheless, the existence of contradictory data and the lack of standardization for the models used have led to a less conclusive interpretation of these data.

Identifying Hub Genes, Key Pathways and Immune Cell Infiltration Characteristics in Pediatric and Adult Ulcerative Colitis by Integrated Bioinformatic Analysis

BACKGROUND AND AIMS

In the present study, we investigated the differentially expressed genes (DEGs), pathways and immune cell infiltration characteristics of pediatric and adult ulcerative colitis (UC).

METHODS

We conducted DEG analysis using the microarray dataset GSE87473 containing 19 pediatric and 87 adult UC samples downloaded from the Gene Expression Omnibus. Gene ontology and pathway enrichment analyses were conducted using Metascape. We constructed the protein-protein interaction (PPI) network and the drug-target interaction network of DEGs and identified hub modules and genes using Cytoscape and analyzed immune cell infiltration in pediatric and adult UC using CIBERSORT.

RESULTS

In total, 1700 DEGs were screened from the dataset. These genes were enriched mainly in inter-cellular items relating to cell junctions, cell adhesion, actin cytoskeleton and transmembrane receptor signaling pathways and intra-cellular items relating to the splicing, metabolism and localization of RNA. CDC42, POLR2A, RAC1, PIK3R1, MAPK1 and SRC were identified as hub DEGs. Immune cell infiltration analysis revealed higher proportions of naive B cells, resting memory T helper cells, regulatory T cells, monocytes, M0 macrophages and activated mast cells in pediatric UC, along with lower proportions of memory B cells, follicular helper T cells, γδ T cells, M2 macrophages, and activated dendritic cells.

CONCLUSIONS

Our study suggested that hub genes CDC42, POLR2A, RAC1, PIK3R1, MAPK1 and SRC and immune cells including B cells, T cells, monocytes, macrophages and mast cells play vital roles in the pathological differences between pediatric and adult UC and may serve as potential biomarkers in the diagnosis and treatment of UC.

Pediatric Crohn disease is characterized by Th1 in the terminal ileum and Th1/Th17 immune response in the colon

The aim of this study was to assess the expression of inflammatory mediators in the affected terminal ileum and colon in pediatric Crohn disease (CD) patients with different stages of disease. Additionally, we assessed the role of efflux transporters in disease pathogenesis and their correlation with immune response. The study included 26 CD patients (10 newly diagnosed (CD-new), 8 CD-treated, and 8 CD-remission) and 15 control subjects. The terminal ileum IFN-γ, IL-6, and IL-1β were elevated in CD-new, while in the colon, the IFN-γ, IL-17A, and IL-6 were elevated in both CD-new and CD-treated subgroups. SOCS3 expression was elevated in both subgroups with active inflammation at both ileum and colon, while SOCS1 was elevated only in CD-new ileum and CD-treated colon. MDR1 expression in ileum was reduced in both subgroups with active inflammation, while BCRP was reduced only in CD-new subgroup.

CONCLUSION

New onset pediatric CD is characterized by Th1 response in ileum and mixed Th1/Th17 response in the colon, with elevated expressions of innate IL-6 and IL-1β. SOCS1/SOCS3 expressions seem to be insufficient for the regulation of the immune response. The reduction in MDR1 expression points to its role in the disease pathogenesis. What is Known: • CD is characterized by an aberrant immune response What is New: • The immune response in new onset pediatric CD differs between terminal ileum and colon • MDR1 expression is downregulated at both terminal ileum and colon irrespective of the disease activity.