Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract characterized by inflammation and ulceration of the intestinal mucosa, represented by Crohn's disease (CD) and ulcerative colitis (UC). The aim of this study is to investigate the relationship between the Ring Finger Protein 186 (RNF186) rs3806308 variant and IBD, as well as to determine whether zonulin levels are associated with IBD.

Ninety-nine patients with inflammatory bowel disease were included in the study. The real-time PCR method was used to detect RNF186 gene polymorphism. Also serum zonulin levels were determined by using Enzyme Linked Immunosorbent Assay (ELISA) technique.

No difference was found between the groups in terms of RNF186 genotype and allele distributions (p > 0.05). CC genotype was associated with high levels of C-reactive protein (CRP) in total patients and CD compared to CT (p < 0.05).

The present study is the first study conducted in our country in terms of examining RNF 186 gene polymorphism and serum zonulin levels.

Background/Objectives: Vitamin D (VD) has immunoregulatory properties, generating interest in its potential to influence therapeutic outcomes in inflammatory bowel disease (IBD), other than affecting the expression of genes encoding enzymes and transporters involved in drug metabolism and transport. This study investigated VD-related single nucleotide polymorphisms (SNPs) as predictors of clinical responses in patients with Crohn's disease (CD) and ulcerative colitis (UC) treated with vedolizumab (VDZ) or ustekinumab (UST) after 3 (T3) and 12 months (T12), as well as the achievement of fecal calprotectin (FC) levels < 250 mg/kg, a marker of mucosal healing. Methods: In this prospective study, 103 patients (67 CD, 36 UC) were enrolled, 40 receiving VDZ and 63 receiving UST. SNPs in the genes CYP24A1, GC, CYP27B1, and VD receptor (VDR) were analyzed via polymerase chain reaction (PCR) and associated with clinical and laboratory outcomes. Results: UST therapy demonstrated a higher clinical response rate at T12 compared to VDZ (p = 0.03). A correlation was found between response at T3 and T12 (p = 0.0002). GC 1296 AC polymorphism negatively predicted response at T12, with 63.6% of non-responders carrying this genotype. CYP24A1 8620 AG was a negative predictor for achieving FC < 250 mg/kg (p = 0.045). CYP24A1 22776 CT and VDR Cdx2 GG increased the likelihood of presenting CD over UC (OR 3.40, p = 0.009 and OR 3.74, p = 0.047, respectively). Additionally, CYP27B1 -1260 GT and +2838 CT increased the likelihood of non-ileal CD (OR 3.13, p = 0.054; OR 7.02, p = 0.01). Conclusions: This study reveals associations between VD-SNPs, clinical response to VDZ and UST, and IBD phenotype and localization, supporting the development of personalized IBD treatment and warranting further validation.

Ulcerative colitis (UC) is a chronic immune-mediated inflammation of the colorectum, for which infliximab (IFX) is currently the mainstay of treatment. However, one-third of patients with UC still fail to benefit from the IFX therapy, and early exposure to IFX impairs the efficacy of other subsequent biologics. Therefore, personalized therapeutic system is urgently needed to assist in clinical decision-making and precision treatment.

Four microarray datasets of colonic biopsies from UC patients treated with IFX were obtained from the GEO database to form the Training Cohort and Validation Cohort. Differentially expressed genes (DEGs) in Training Cohort were identified and enriched for GO, KEGG and immune cell infiltration analysis. A prediction model for IFX efficacy was developed based on the LASSO and Logistic regression. The predictive accuracy of the model was verified by the Validation Cohort, and the model-genes/proteins were validated by immunohistochemistry. Gene-drug, gene-ncRNA interaction analysis were performed to identify drugs or non-coding RNAs (ncRNAs) that potentially interacted with the model-genes. Homology Modeling and Molecular Docking were conducted to filter the optimal candidate as the subsequent adjuvant or alternative for IFX in predicted non-responders. At last, the down-regulation of the key model-gene/protein CYP24A1 by the drug candidate Deferasirox was verified by Western Blot and qRT-PCR Assay based on cellular experiments.

A total of 113 DEGs were identified in the Training Cohort, mainly enriched in inflammatory cell chemotaxis, migration, and response to molecules derived from intestinal microbiota. Activated pro-inflammatory innate immune cells, including neutrophils, M1 macrophages, activated dendritic cells and mast cells, were significantly enriched in colons of non-responders. The prediction model based on three model-genes (IFI44L, CYP24A1, and RGS1) exhibited strong predictive efficacy, with AUC values of 0.901 and 0.80 in the Training and Validation Cohorts, respectively. Higher expression of the three model-genes/proteins in colons of non-responders to IFX was confirmed by clinical colonic mucosal biopsies. 4 Drugs (Calcitriol, Lunacalcipol, Deferasirox, Telaprevir), 15 miRNAs and 66 corresponding lnRNAs interacting with model-genes were identified. The protein 3D structure of the key model-gene/protein (human-derived CYP24A1) was developed. Through the Molecular Docking and cellular experimental validation, Deferasirox, which significantly down-regulated both the RNA and protein expression of CYP24A1, was identified as the optimal adjuvant or alternative for IFX in predicted non-responders with UC.

This study developed a novel prediction model for pre-assessing the efficacy of IFX in patients with UC, as the first step towards personalized therapy. Meanwhile, drugs and non-coding RNAs were provided as potential candidates to develop the next-step precise treatment for the predicted non-responders. In particular, Defeasirox appears to hold promise as an adjuvant or alternative to IFX for the optimization of UC therapy.

The vitamin D receptor (VDR), binding to the active form of the vitamin, promotes the transcription of numerous genes involved in the proliferation of immune cells, cytokine production and lymphocyte activation. It is known that vitamin D deficiency can influence the risk of developing rheumatoid arthritis (RA) or modulate its disease activity. The aim of this study was to investigate a possible association between the rs11568820 (C > T) polymorphism in the promoter region of VDR gene and the response to therapy with anti-TNF drugs in patients with RA. A total of 178 consecutive Italian patients with RA treated with anti-TNF, naïve for biological therapy, were recruited. Disease activity data were evaluated using specific indices such as DAS28, CDAI and SDAI, measured at the start of therapy and subsequently at 22, 52, 104 and 240 weeks. A statistically significant association emerged between the rs11568820 variant allele of VDR gene and failure to remission assessed by CDAI and SDAI at 52 weeks, and by DAS28, CDAI and SDAI at 104 weeks of follow-up. Furthermore, the variant allele of this polymorphism was observed more frequently in patients who did not undergo sustained remission calculated by CDAI and SDAI. The variant T allele of rs11568820 in VDR gene is associated with a reduced remission rate with anti-TNFα drugs. These data suggest the role of VDR genetic variability in the response to therapy and in the achievement of remission.