High-Throughput Sequencing of microRNAs in Glucocorticoid Sensitive Paediatric Inflammatory Bowel Disease Patients

Abstract

The aim of this research was the identification of novel pharmacogenomic biomarkers for better understanding the complex gene regulation mechanisms underpinning glucocorticoid (GC) action in paediatric inflammatory bowel disease (IBD). This goal was achieved by evaluating high-throughput microRNA (miRNA) profiles during GC treatment, integrated with the assessment of expression changes in GC receptor (GR) heterocomplex genes. Furthermore, we tested the hypothesis that differentially expressed miRNAs could be directly regulated by GCs through investigating the presence of GC responsive elements (GREs) in their gene promoters. Ten IBD paediatric patients responding to GCs were enrolled. Peripheral blood was obtained at diagnosis (T0) and after four weeks of steroid treatment (T4). MicroRNA profiles were analyzed using next generation sequencing, and selected significantly differentially expressed miRNAs were validated by quantitative reverse transcription-polymerase chain reaction. In detail, 18 miRNAs were differentially expressed from T0 to T4, 16 of which were upregulated and 2 of which were downregulated. Out of these, three miRNAs (miR-144, miR-142, and miR-96) could putatively recognize the 3’UTR of the GR gene and three miRNAs (miR-363, miR-96, miR-142) contained GREs sequences, thereby potentially enabling direct regulation by the GR. In conclusion, we identified miRNAs differently expressed during GC treatment and miRNAs which could be directly regulated by GCs in blood cells of young IBD patients. These results could represent a first step towards their translation as pharmacogenomic biomarkers.

Azathioprine Biotransformation in Young Patients with Inflammatory Bowel Disease: Contribution of Glutathione-S Transferase M1 and A1 Variants

“…However, when the analysis was extended to young adults (age less than 30 years), the correlation between age and the TGN/dose ratio was lost. This may be related to environmental factors, including epigenetic determinants, even if more studies are needed to elucidate the mechanisms underlying these observations [27].…”

NGS study of glucocorticoids response genes in inflammatory bowel disease patients

“…Thus, in the next step, we are planning to correlate these SNVs with clinical data concerning the GC effect. The especially high importance of non-exonic variants was proved by de Iudicibus et al in recent research, because of binding sites for microRNA [38]. Moreover, it should be taken into account that for personalized glucocorticoid treatment in IBD, a comprehensive approach integrating both genome and transcriptome research, including coding and non-coding RNA, will be necessary [39].…”

Inflammatory Bowel Disease: A Personalized Approach

“…′ untranslated region of the GR gene (41). Thiopurine drug monitoring is a successful paradigm of personalized treatment.…”

“…Next-generation sequencing performed in leucocytes of children with IBD at diagnosis and 4 weeks following introduction of CS showed significantly altered expression of 18 micro-RNAs; three of these micro-RNAs contained glucocorticoid-responsive elements in their gene promoters and could be putatively directly regulated by the GC receptor, while others recognized 3′ untranslated region of the GR gene ( 41 ).…”