Marianna Lucafò1*, Letizia Pugnetti2, Debora Curci2, Carlotta Bidoli1, Marco Gerdol1, Fulvio Celsi2, Sara Renzo3, Monica Paci3, Sara Lega2, Paolo Lionetti3, Alberto Pallavicini1, Giuliana Decorti2,4, Gabriele Stocco2,4, Matteo Bramuzzo2
1Department of Life Sciences, University of Trieste, Trieste, 34127, Italy
2Institute for Maternal and Child Health, IRCCS “Burlo Garofolo”, Trieste, 34137, Italy
3Gastroenterology and Nutrition Unit, Meyer Children’s Hospital IRCSS, Florence, 50139, Italy
4Department of Medicine, Surgery and Health Sciences, University of Trieste, Italy
mlucafo [at] units.it
Abstract
Thalidomide has emerged as an effective immunomodulator in the treatment of pediatric patients with inflammatory bowel disease (IBD) refractory to standard therapies. Cereblon, a component of E3 protein ligase complex that mediates ubiquitination and proteasomal degradation of target proteins, has been identified as the primary target of thalidomide. Cereblon plays a crucial role in thalidomide teratogenicity, however it is unclear whether it is also involved in the therapeutic effects in IBD patients. This study aimed at identifying the mechanisms underpinning thalidomide action in pediatric IBD. Ten IBD pediatric patients clinically responsive to thalidomide were prospectively enrolled. RNA-sequencing and functional enrichment analysis was carried out on peripheral blood mononuclear cells obtained before and after treatment with thalidomide. RNA-sequencing analysis revealed 378 differentially expressed genes after treatment with thalidomide. The most deregulated pathways were cytosolic calcium ion concentration, cAMP-mediated signaling, eicosanoid signaling and inhibition of matrix metalloproteinases. Neuronal signaling mechanisms such as CREB signaling in neurons and axonal guidance signaling also emerged. Connectivity Map analysis revealed that thalidomide gene expression changes were similar to those induced by MLN4924, an inhibitor of NEDD8 activating enzyme, suggesting that thalidomide exerts its immunomodulatory effects by acting on the ubiquitin-proteasome pathway.
In vitro experiments on cell lines confirmed the effect of thalidomide on altered candidate pathways observed in patients. These results represent a unique resource for enhanced understanding of thalidomide mechanism in patients with IBD, providing novel potential targets associated with drug response.
Keywords: RNA-sequencing, thalidomide, pediatric, Crohn’s disease, ulcerative colitis
Acknowledgement: This work was supported by the Italian Ministry of Health, through the contribution given to the Institute for Maternal and Child Health IRCCS Burlo Garofolo, Trieste, Italy, grant NET-2013-02355002 and RC 10/19.
