Pharmacological Activation of the Bile Acid Nuclear Farnesoid X Receptor Is Feasible in Patients with Quiescent Crohn's Colitis

<div><h3>Background</h3><p>The bile acid-activated nuclear receptor Farnesoid X Receptor (FXR) is critical in maintaining intestinal barrier integrity and preventing bacterial overgrowth. Patients with Crohn's colitis (CC) exhibit reduced ileal FXR target gene expression. FXR agonists have been shown to ameliorate inflammation in murine colitis models. We here explore the feasibility of pharmacological FXR activation in CC.</p> <h3>Methods</h3><p>Nine patients with quiescent CC and 12 disease controls were treated with the FXR ligand chenodeoxycholic acid (CDCA; 15 mg/kg/day) for 8 days. Ileal FXR activation was assessed in the fasting state during 6 hrs after the first CDCA dose and on day 8, by quantification of serum levels of fibroblast growth factor (FGF) 19. Since FGF19 induces gallbladder (GB) refilling in murine models, we also determined concurrent GB volumes by ultrasound. On day 8 ileal and cecal biopsies were obtained and FXR target gene expression was determined.</p> <h3>Results</h3><p>At baseline, FGF19 levels were not different between CC and disease controls. After the first CDCA dose, there were progressive increases of FGF19 levels and GB volumes during the next 6 hours in CC patients and disease controls (FGF19: 576 resp. 537% of basal; GB volumes: 190 resp. 178% of basal) without differences between both groups, and a further increase at day 8. In comparison with a separate untreated control group, CDCA affected FXR target gene expression in both CC and disease controls, without differences between both groups.</p> <h3>Conclusions</h3><p>Pharmacological activation of FXR is feasible in patients with CC. These data provide a rationale to explore the anti-inflammatory properties of pharmacological activation of FXR in these patients.</p> <h3>Trial Registration</h3><p>TrialRegister.nl <a href="http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2009">NTR2009</a></p> </div

Disease characte.ristics of patients with Crohn's colitis at previous investigations and current investigation.

<p>Data presented as numbers (% of group).</p><p>Disease extent was divided in more or less than 50% colonic involvement; disease extent of more than 50% was defined as involvement of three or more anatomical parts of the colon;</p>*<p>disease behavior according to the Montreal Classification <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0049706#pone.0049706-Satsangi1" target="_blank">[24]</a>.</p

Plasma FGF19 levels (SEM) as a function of time after ingestion of chenodeoxycholic acid in patients with Crohn's colitis and disease controls.

<p>FGF19 levels progressively rise in all patients (p = 0.00) without differences between both groups Crohn's patients; Disease controls.</p

Gallbladder dynamics in patients with Crohn's colitis and disease controls during the first 6 hours after CDCA ingestion and after 8 days of CDCA ingestion.

<p>Values are in means ± SD; CDCA, chenodeoxycholic acid; <i>V0</i>, baseline fasting gallbladder volume (mean of 3 measurements);<i>V_min</i> (mL), minimal gallbladder volume; <i>V_min</i> (%), minimal gallbladder volume as percentage of V0; <i>ΔV_min</i> (mL), difference between Vmin and V0; <i>ΔV_min</i> (%), percentual difference between Vmin and V0; <i>Time V_min</i> (hours), time to minimal gallbladder volume from t0; <i>V_max</i> (mL), maximal gallbladder volume; <i>V_max</i> (%), maximal gallbladder volume as percentage of V0; <i>ΔV_max</i> (mL), difference between Vmax and V0; <i>ΔV_max</i> (%), percentual difference between Vmax and V0; <i>Time V_max</i> (hours), time to maximal gallbladder volume from t0; <i>AUC</i> (mL*360 min), area under the curve of change of gallbladder volume during 360 minutes; <i>AUC</i> (percent*360 min), area under the curve of percentual change of gallbladder volume during 360 minutes; <i>V_t8</i> (mL), gallbladder volume after 8 days of CDCA ingestion; <i>V_t8</i> (%), <i>V_t8</i> as percentage of V0; <i>ΔV_t8</i> (mL), difference between V_t8 and V0; <i>ΔV_t8</i> (%), percentage difference between V_t8 and V0.</p

Ileal mRNA expression levels of FXR and FXR target genes in patients with Crohn's colitis and disease controls after CDCA stimulation.

<p>Data in median [range]; p-values according to Mann-Whitney-U test.</p><p>Expression levels are given as fold change compared to a separate group of disease controls without CDCA stimulation (see text).</p

FGF19 dynamics in patients with Crohn's colitis and disease controls during the first 6 hours after CDCA ingestion and after 8 days of CDCA ingestion.

<p>Values are in means ± SD; CDCA, chenodeoxycholic acid; <i>FGF19_t0,</i> baseline fasting FGF19 level; <i>FGF19_min</i> (ng/mL), minimal FGF19 level in ng/mL; <i>FGF19_min</i> (%), minimal FGF19 level as percentage of FGF_t0; <i>ΔFGF19_min</i> (ng/mL), difference between FGFmin and FGF_t0; <i>ΔFGF19_min</i> (%), percentage difference between FGFmin and FGF_t0; <i>Time FGF19_min</i> (hours), time to minimal FGF19 level from t0; <i>FGF19_max</i> (ng/mL), maximal FGF19 level; <i>FGF19_max</i> (%), maximal FGF19 level as percentage of FGF_t0; <i>ΔFGF19_max</i> (ng/mL), difference between FGFmax and FGF_t0; <i>ΔFGF19_max</i> (%), percentual difference between FGFmax and FGF_t0; <i>Time FGF19_max</i> (hours), time to maximal FGF19 level from t0; <i>AUC</i> (ng/mL*360 min), area under the curve of change of FGF19 level during 360 minutes; <i>AUC</i> (percent*360 min), area under the curve of percentage change of FGF19 level during 360 minutes; <i>FGF19_t8</i> (ng/mL), FGF19 level after 8 days of CDCA ingestion; <i>FGF19_t8</i> (%) FGF_t8 as percentage of FGF_t0; <i>ΔFGF19_t8</i> (ng/mL), difference between FGF19_t8 and FGF19_t0; <i>ΔFGF19_t8</i> (%), percentage difference between FGF19_t8 and FGF19_t0.</p

Gallbladder volume as a function of time after ingestion of chenodeoxycholic acid in patients with Crohn's colitis and disease controls.

<p>Gallbladder volumes progressively rise in all patients (p = 0.00) without differences between both groups Crohn's patients; Disease controls.</p

Overview of the screening and replication strategy for rare variants.

<p>Phase I: a) targeted re-sequencing of 122 genes was performed in a pooled design of 790 Dutch UC cases. Five hundred healthy individuals sequenced by the Genome of the Netherlands Project were used as a control cohort. After quality control, 2562 high-confidence variants were further prioritized based on allele frequency and likely pathogenicity. In total 188 SNVs were selected for replication phase 1 (Phase II), of which 171 passed the design of five Agena Biosience iPlexes. (<a href="http://agenabio.com" target="_blank">http://agenabio.com</a>) b) Phase II: genotyping of 171 variants was performed in 1021 Dutch UC cases and 1166 controls. c) Phase III: after association and gene-based analyses, genotyping of 19 variants was performed in 1026 German UC cases and 3532 healthy German controls.</p

Predicted loss of function variants identified by pooled sequencing (Phase I), and genotyped in replication phase 1 (Phase II).

<p>Predicted loss of function variants identified by pooled sequencing (Phase I), and genotyped in replication phase 1 (Phase II).</p

Significant SNVs in Replication phase 1 (Phase II) and replication phase 2 (Phase III).

<p>Significant SNVs in Replication phase 1 (Phase II) and replication phase 2 (Phase III).</p