Healing In Colitis Research Articles

Claudin-2: A marker for a better evaluation of histological mucosal healing in inflammatory bowel diseases

BackgroundHistological mucosal healing has become a paramount target goal to achieve in the treatment of inflammatory bowel diseases. However, there is still a lack of agreement on the best way to reach this goal, since numerous histological scores are available worldwide. AimsWe investigated whether claudin-2, a member of claudin family involved in the regulation of intestinal tight junctions, might be useful to assess the presence of active disease in patients with inflammatory bowel diseases. MethodsBiopsies from 123 patients with ulcerative colitis, Crohn's disease, infectious colitides and irritable bowel syndrome patients where tested with immunohistochemistry for claudin-2. ResultsClaudin-2 appeared to be a very sensitive marker of disease activity in inflammatory bowel diseases, but was negative in the other kinds of patients. In addition, immunohistochemistry for claudin-2 showed good reproducibility by different pathologists. ConclusionsShould these findings be confirmed in more numerous cohorts of patients, and especially in those with minimal or focal residual disease activity, this simple assessment could be useful in the routine daily practice to facilitate the task of pathologists and clinicians in the diagnosis and management of patients with inflammatory bowel diseases.

Fecal calprotectin and endoscopic scores: The cornerstones in clinical practice for evaluating mucosal healing in inflammatory bowel disease

Managing inflammatory bowel disease (IBD) is becoming increasingly complex and personalized, considering the advent of new advanced therapies with distinct mechanisms of action. Achieving mucosal healing (MH) is a pivotal therapeutic goal in IBD management and can prevent IBD progression and reduce flares, hospitalization, surgery, intestinal damage, and colorectal cancer. Employing proactive disease and therapy assessment is essential to achieve better control of intestinal inflammation, even if subclinical, to alter the natural course of IBD. Periodic monitoring of fecal calprotectin (FC) levels and interval endoscopic evaluations are cornerstones for evaluating response/remission to advanced therapies targeting IBD, assessing MH, and detecting subclinical recurrence. Here, we comment on the article by Ishida et al Moreover, this editorial aimed to review the role of FC and endoscopic scores in predicting MH in patients with IBD. Furthermore, we intend to present some evidence on the role of these markers in future targets, such as histological and transmural healing. Additional prospective multicenter studies with a stricter MH criterion, standardized endoscopic and histopathological analyses, and virtual chromoscopy, potentially including artificial intelligence and other biomarkers, are desired.

Rapamycin promotes the intestinal barrier repair in ulcerative colitis via the mTOR/PBLD/AMOT signaling pathway

Intestinal barrier dysfunction characterized by the functional loss of the intestinal epithelium's tight junction (TJ) barrier is a key factor in the pathogenesis of ulcerative colitis (UC). Although rapamycin, an mTOR (mechanistic target of rapamycin) inhibitor, has shown promise in inducing clinical remission and mucosal healing in inflammatory bowel disease, its underlying mechanism remains elusive. Thus, this study investigated the role of the mTOR pathway in regulating the intestinal barrier. To investigate the molecular mechanism regulating the intestinal barrier, specific intestinal epithelial phenazine biosynthesis-like domain-containing protein (PBLD)-deficient (PBLDIEC−/−) mice and control wild-type (WT) mice were intraperitoneally injected with rapamycin or MHY1485. To determine the relevance of the findings for UC, we analyzed transcriptome data and single-cell expression profiles from public databases and intestinal mucosal tissues obtained from patients with active UC or colon cancer. We observed that mTOR activation in the intestinal epithelium of patients with active UC. Moreover, in vivo, rapamycin markedly increased the expressions of PBLD and TJ proteins and reduced intestinal inflammation in mice with dextran sulfate sodium-induced enteritis. However, the therapeutic efficacy of rapamycin was notably reduced in PBLDIEC−/− mice. In vitro, rapamycin influenced PBLD expression by modulating the nuclear transcription of transcription factor EB (TFEB). Angiomotin (AMOT) could directly bind to PBLD, and rapamycin could not effectively increase the expression of TJ proteins after the knockdown of PBLD or AMOT. In summary, the administration of rapamycin is a potential treatment for UC, and targeting the mTOR/PBLD/AMOT axis is a potential novel approach for UC treatment.

Aloe emodin promotes mucosal healing by modifying the differentiation fate of enteroendocrine cells via regulating cellular free fatty acid sensitivity

The proper differentiation and reorganization of the intestinal epithelial cell population is critical to mucosal regeneration post injury. Label retaining cells (LRCs) expressing SRY-box transcription factor 9 (SOX9) promote epithelial repair by replenishing LGR5+ intestinal stem cells (ISCs). While, LRCs are also considered precursor cells for enteroendocrine cells (EECs) which exacerbate mucosal damage in inflammatory bowel disease (IBD). The factors that determine LRC-EEC differentiation and the effect of intervening in LRC-EEC differentiation on IBD remain unclear. In this study, we investigated the effects of a natural anthraquinone called aloe emodin (derived from the Chinese herb rhubarb) on mucosal healing in IBD models. Our findings demonstrated that aloe emodin effectively interfered with the differentiation to EECs and preserved a higher number of SOX9+ LRCs, thereby promoting mucosal healing. Furthermore, we discovered that aloe emodin acted as an antagonist of free fatty acid receptors (FFAR1), suppressing the FFAR1-mediated Gβγ/serine/threonine-protein kinase (AKT) pathway and promoting the translocation of forkhead box protein O1 (FOXO1) into the nucleus, ultimately resulting in the intervention of differentiation fate. These findings reveal the effect of free fatty acid accessibility on EEC differentiation and introduce a strategy for promoting mucosal healing in IBD by regulating the FFAR1/AKT/FOXO1 signaling pathway.

Exploring microbial engineering for enhanced mucosal healing in inflammatory bowel disease

Exploring microbial engineering for enhanced mucosal healing in inflammatory bowel disease

REPRESSED MITOCHONDRIAL FUNCTION LIMITS CRYPT FISSIONING IN INFLAMMATORY BOWEL DISEASE

Abstract BACKGROUND Mucosal healing in inflammatory bowel disease (IBD) is a predictor of remission. Unfortunately, many IBD patients remain refractory or lose responsiveness to therapies leading to persistent mucosal ulceration. Prospective pediatric studies suggest that reduced mitochondrial gene expression associates with unfavorable clinical outcomes in ulcerative colitis (UC) and Crohn’s disease (CD). In this study, we postulate that in diverticulitis (DvC) patients, moderate-to-severe level of tissue inflammation induces fissioning of crypts with normal level of mitochondria. By comparison, in UC and CD, moderate-to-severe tissue inflammation induces lesser crypt fissioning in part due to lower level of mitochondria in crypt intestinal epithelial cells (IECs). We posit that the inability to restore epithelial mitochondrial respiration attenuates crypt fissioning in IBD compared to DvC. METHODS Surgical resections were collected from patients with colonic DvC (n=39), active Crohn’s disease (CD; n=27), ulcerative colitis (UC; n=21) and uninvolved areas of colorectal cancer patients (normal control, nc). Formalin-fixed paraffin-embedded tissues were H&E-stained to allow examination of crypt architecture, branching and fissioning along with extent of inflammation scored by blinded GI-pathologist. Immunohistochemical (IHC) staining was performed for marker of mitochondrial complex-IV (MTCO1). RESULTS Histological investigations revealed higher number fissioning crypts per 100 crypts in DvC (4.778±2.9) as compared to UC (3.469±1.79) or CD (3.604±1.3) patients. This represents 37.7% and 32.6% higher crypt fissioning in DvC vs UC (**p<0.01) and DvC vs CD (*p<0.05), respectively. Alternate analysis of fissioning crypts per 100μm colonic length showed 83.9±24.8% and 22.8±9.6% more crypt fissioning in DvC compared to UC and CD, respectively. Further, IHC showed higher MTCO1 expression (area %) in DvC (14.32±3.3) compared to UC (6.6±4.85) and CD (9.25±5.9). Interestingly, all three inflammatory conditions (DvC, UC, CD) showed reduction in MTCO1 expression compared to normal control (DvC/nc: 27%; p<0.067, UC/nc: 71%; **p<0.01, CD/nc: 60.3%; **p<0.01), although the MTCO1 suppression in more pronounced in UC and CD. Crypt-specific MTCO1 expression revealed 2.16-fold and 1.55-fold higher MTCO1 levels in DvC compared to UC and CD, respectively. Furthermore, detailed examination of fissioning crypts in DvC, CD and UC patients revealed significantly higher expression of complex-IV protein (MTCO1) compared to non-fissioning crypts. CONCLUSION Overall, our findings suggest that lack of adequate mitochondrial function is associated with perturbed crypt fissioning in IBD patients, in contrast to DvC with comparatively higher mitochondrial complex levels. Thus, mitochondria-targeted therapy may provide an alternative treatment approach for severe chronic IBD patients.

P171 Rescuing Intestinal Stem Cells via TMEM219 inhibition promotes mucosal healing in Crohn’s disease

Abstract Background Intestinal mucosa regeneration is disrupted in inflammatory bowel disease as Chron’s disease, but whether this relies on a defect in intestinal stem cells remains to be established. Methods Transcriptome and receptome profile in Crohn’s disease bioptic samples demonstrated a defect in intestinal stem cells (ISCs). The TMEM219 knockout mouse, in which TMEM219 expression is abrogated on ISCs was tested in dextran sulfate sodium (DSS) acute colitis model. DSS-induced chronic colitis was also used to confirm in vivo relevance for TMEM219 blockade in mucosal recovery. Results An increased intestinal stem cells death and dysfunction in colonic samples obtained from patients with Crohn’s disease was observed, which is controlled through the death factor TMEM219. Based on a receptome analysis, we documented large alterations in the expression of the death receptor TMEM219 in patients with Crohn’s disease, particularly in those with refractory disease and/or non responders to conventional therapy, which were paralleled by altered peripheral levels of the TMEM219 ligand, insulin-like growth factor binding protein 3 (IGFBP3). Pharmacological blockade of the IGFBP3/TMEM219 axis restored the self-renewal abilities of mini-guts generated from patients with Crohn’s disease in vitro, ameliorated DSS-induced colitis in vivo and favored mucosal healing. Genetic deletion of TMEM219 in intestinal stem cells in newly generated TMEM219flflLGR5cre mice restored mucosal regenerative abilities both in vitro and in vivo. Conclusion Our findings demonstrate that genetic and pharmacological TMEM219 blockade re-establishes intestinal self-renewal properties and offers a therapeutic opportunity for mucosal healing in inflammatory bowel disease.

P138 Novel serum markers for predicting disease activity in ulcerative colitis: results from a retrospective case-control study

Abstract Background Commonly used serum or faecal markers, such as C-reactive protein (CRP) and feacal calprotectin have several limitations and do not always correlate well with the degree of mucosal inflammation in the intestine as established by endoscopy. The aim of the current study was to evaluate the utility of a panel of serum markers (Visfatin, serum amyloid, LRG1, MMP-1, MMP-2, TFF3, Lipocalin-2 (NGAL), IL-6, IL-4, IL-7, IL-17) in predicting mucosal inflammation in ulcerative colitis(UC) patients. Methods We conducted an unmatched case-control retrospective study. Patients were selected consecutively, based on their enrollement date, from a prospective IBD cohort. We selected two groups of UC patients, each of them with active disease at baseline and different outcomes during follow-up: mucosal healing and persistant disease activity, as resulted from clinical and endoscopic evaluation. Inflammatory burden was investigated using the C-reactive protein and endoscopic activity was reported using the Mayo endoscopic score. Quality of life was also evaluated at each visit using The Short Inflammatory Bowel Disease Questionnaire (SIBDQ). Clinical disease activity was quantified using the partial Mayo score. Clinical remission was defined as a partial Mayo score < 2. Endoscopic activity was assessed using the Mayo endoscopic score[i] . Mucosal healing was defined as Mayo endoscopic score of 0. The selection of investigated biomarkers was based on the results of a systematic review previously published by the research team [i] State M, Negreanu L, Voiosu T, Voiosu A, Balanescu P, Mateescu RB. Surrogate markers of mucosal healing in inflammatory bowel disease: A systematic review. World J Gastroenterol. 2021 Apr 28;27(16):1828-1840. doi: 10.3748/wjg.v27.i16.1828. Results 84 serum samples from 42 patients were retrospectively analyzed (21 patients with mucosal healing and 21 patients with persistant activity during follow-up). Lipocalin proved to be a reliable marker for the noninvasive assessment of endoscopic activity, with 90% sensitivity and 95% specificity at a cut-off level of 0,421μg/ml (AUROC 0,677). The combination of lipocalin, age, gender and BMI (Figure 1) is a good predictor of persistant activity during follow-up (AUROC 0.87, 95% CI, 0.762-0.979). Conclusion Our findings provide support for the use of lipocalin as a surrogate marker for mucosal inflammation. The combination of lipocalin, age, gender and BMI might be useful for guiding treatment and monitoring decisions.

Emerging strategy towards mucosal healing in inflammatory bowel disease: what the future holds?

For decades, the therapeutic goal of conventional treatment among inflammatory bowel disease (IBD) patients is alleviating exacerbations in acute phase, maintaining remission, reducing recurrence, preventing complications, and increasing quality of life. However, the persistent mucosal/submucosal inflammation tends to cause irreversible changes in the intestinal structure, which can barely be redressed by conventional treatment. In the late 1990s, monoclonal biologics, mainly anti-TNF (tumor necrosis factor) drugs, were proven significantly helpful in inhibiting mucosal inflammation and improving prognosis in clinical trials. Meanwhile, mucosal healing (MH), as a key endoscopic and histological measurement closely associated with the severity of symptoms, has been proposed as primary outcome measures. With deeper comprehension of the mucosal microenvironment, stem cell niche, and underlying mucosal repair mechanisms, diverse potential strategies apart from monoclonal antibodies have been arising or undergoing clinical trials. Herein, we elucidate key steps or targets during the course of MH and review some promising treatment strategies capable of promoting MH in IBD.

Faecalibacterium prausnitzii promotes intestinal epithelial IL-18 production through activation of the HIF1α pathway.

Intestinal epithelial cells produce interleukin-18 (IL-18), a key factor in promoting epithelial barrier integrity. Here, we analyzed the potential role of gut bacteria and the hypoxia-inducible factor 1α (HIF1α) pathway in regulating mucosal IL18 expression in inflammatory bowel disease (IBD). Mucosal samples from patients with IBD (n = 760) were analyzed for bacterial composition, IL18 levels and HIF1α pathway activation. Wild-type Caco-2 and CRISPR/Cas9-engineered Caco-2-HIF1A-null cells were cocultured with Faecalibacterium prausnitzii in a "Human oxygen-Bacteria anaerobic" in vitro system and analyzed by RNA sequencing. Mucosal IL18 mRNA levels correlated positively with the abundance of mucosal-associated butyrate-producing bacteria, in particular F. prausnitzii, and with HIF1α pathway activation in patients with IBD. HIF1α-mediated expression of IL18, either by a pharmacological agonist (dimethyloxallyl glycine) or F. prausnitzii, was abrogated in Caco-2-HIF1A-null cells. Butyrate-producing gut bacteria like F. prausnitzii regulate mucosal IL18 expression in a HIF1α-dependent manner that may aid in mucosal healing in IBD.

Ischemia-modified albumin: a novel blood marker of endoscopic mucosal healing in inflammatory bowel disease.

The achievement of endoscopic remission is an important therapeutic goal in the treatment of inflammatory bowel diseases (IBD). We aimed to evaluate the role of fecal calprotectin (FCP) and ischemia-modified albumin (IMA) as biomarkers for evaluating IBD disease activity. A total of 48 patients with IBD (20 with ulcerative colitis and 28 with Crohn's disease) were included in this study. FCP and serum C-reactive protein levels, erythrocyte sedimentation rate, and IMA were measured in patients with IBD and compared with endoscopic findings. Elevated FCP and serum IMA levels were significantly associated with endoscopic non-mucosal healing. The correlation between FCP and IMA was not significant. Analysis of the receiver operating characteristic curve showed that both FCP and IMA had diagnostic value in predicting non-mucosal healing. When the Ln(FCP)+IMA/10 value was calculated using both factors, the predictive value for non-mucosal healing increased; however, no significant difference was observed. IMA could be a candidate serum biomarker for predicting endoscopic mucosal healing in IBD.

Higher Adalimumab Trough Levels Are Associated with Histologic Remission and Mucosal Healing in Inflammatory Bowel Disease.

(1) Many patients with inflammatory bowel disease (IBD) in endoscopic remission have persistent histologic activity, which is associated with worse outcomes. There are limited data on the association between adalimumab drug concentrations and histologic outcomes using validated histologic indices. We aimed to assess the relationship between adalimumab concentrations and the Robarts Histopathology Index (RHI). (2) Patients from a tertiary IBD center from 2013 to 2020 with serum adalimumab (ADA) trough concentrations measured during maintenance therapy (≥14 weeks) and a colonoscopy or flexible sigmoidoscopy with biopsies performed within 90 days of drug level were included. Blinded histologic scoring using the RHI was performed. Primary analysis assessed the relationship between adalimumab drug concentrations and histologic remission using receiver operating characteristic curve analysis. (3) In 36 patients (26 Crohn's Disease, 9 ulcerative colitis, 1 indeterminate), median adalimumab concentrations were higher (17.3 ug/mL, 12.2-24.0) in patients with histologic remission compared to those without (10.3 ug/mL, 6.8-13.9, p = 0.008). The optimal ADA concentration identified using the Youden threshold was ≥16.3 ug/mL (sensitivity 70%, specificity 90%). Patients with ADA ≥ 16.3 ug/mL had higher histologic remission rates (78%) compared to lower ADA concentrations (14%, p= 0.002), as well as higher mucosal healing rates (86%) compared to lower levels (12%, p = 0.001). Symptoms correlated weakly and non-significantly with both histologic (RHI) scores (r = 0.25, p = 0.2) and adalimumab concentrations (r = 0.05, p = 0.8). (4) The current study demonstrated that higher serum adalimumab concentrations (≥16.3 ug/mL) are needed for histologic remission and mucosal healing assessed using the RHI.

The Role of Adipose Tissue Mesenchymal Stem Cells in Colonic Anastomosis Healing in Inflammatory Bowel Disease: Experimental Study in Rats.

(1) Background: A surgical operation on an inflamed bowel is, diachronically, a challenge for the surgeon, especially for patients with inflammatory bowel disease. Adipose tissue-derived mesenchymal stromal cells are already in use in clinical settings for their anti-inflammatory properties. The rationale of the current study was to use AdMSCs in high-risk anastomoses to monitor if they attenuate inflammation and prevent anastomotic leak. (2) Methods: a total of 4 groups of rats were subjected to a surgical transection of the large intestine and primary anastomosis. In two groups, DSS 5% was administered for 7 days prior to the procedure, to induce acute intestinal inflammation. After the anastomosis, 5 × 106 autologous AdMSCs or an acellular solution was injected locally. Macroscopic evaluation, bursting pressure, hydroxyproline, and inflammatory cytokine expression were the parameters measured on the 8th post-operative day. (3) Results: Significantly less intra-abdominal complications, higher bursting pressures, and a decrease in pro-inflammatory markers were found in the groups that received AdMSCs. No difference in VEGF expression was observed on the 8th post-operative day. (4) Conclusions: AdMSCs attenuate inflammation in cases of acutely inflamed anastomosis.

Long-term disease course, cost and prognosis of inflammatory bowel disease: epidemiological studies of a European and a Danish inception cohort.

Long-term disease course, cost and prognosis of inflammatory bowel disease: epidemiological studies of a European and a Danish inception cohort.

Claudin Barriers on the Brink: How Conflicting Tissue and Cellular Priorities Drive IBD Pathogenesis.

Inflammatory bowel diseases (IBDs) are characterized by acute or chronic recurring inflammation of the intestinal mucosa, often with increasing severity over time. Life-long morbidities and diminishing quality of life for IBD patients compel a search for a better understanding of the molecular contributors to disease progression. One unifying feature of IBDs is the failure of the gut to form an effective barrier, a core role for intercellular complexes called tight junctions. In this review, the claudin family of tight junction proteins are discussed as they are a fundamental component of intestinal barriers. Importantly, claudin expression and/or protein localization is altered in IBD, leading to the supposition that intestinal barrier dysfunction exacerbates immune hyperactivity and disease. Claudins are a large family of transmembrane structural proteins that constrain the passage of ions, water, or substances between cells. However, growing evidence suggests non-canonical claudin functions during mucosal homeostasis and healing after injury. Therefore, whether claudins participate in adaptive or pathological IBD responses remains an open question. By reviewing current studies, the possibility is assessed that with claudins, a jack-of-all-trades is master of none. Potentially, a robust claudin barrier and wound restitution involve conflicting biophysical phenomena, exposing barrier vulnerabilities and a tissue-wide frailty during healing in IBD.

The Influence of Apremilast-Induced Macrophage Polarization on Intestinal Wound Healing.

There is compelling evidence suggesting a pivotal role played by macrophages in orchestrating intestinal wound healing. Since macrophages display significant plasticity and heterogeneity, exhibiting an either classically activated (M1-like) or alternatively activated (M2-like) phenotype, they can aggravate or attenuate intestinal wound healing. Growing evidence also demonstrates a causal link between impaired mucosal healing in inflammatory bowel disease (IBD) and defects in the polarization of pro-resolving macrophages. By targeting the switch from M1 to M2 macrophages, the phosphodiesterase-4 inhibitor Apremilast has gained recent attention as a potential IBD drug. However, there is a gap in our current knowledge regarding the impact of Apremilast-induced macrophages' polarization on intestinal wound healing. The THP-1 cells were differentiated and polarized into M1 and M2 macrophages, and subsequently treated with Apremilast. Gene expression analysis was performed to characterize macrophage M1 and M2 phenotypes, and to identify possible target genes of Apremilast and the involved pathways. Next, intestinal fibroblast (CCD-18) and epithelial (CaCo-2) cell lines were scratch-wounded and exposed to a conditioned medium of Apremilast-treated macrophages. Apremilast had a clear effect on macrophage polarization, inducing an M1 to M2 phenotype switch, which was associated with NF-κB signaling. In addition, the wound-healing assays revealed an indirect influence of Apremilast on fibroblast migration. Our results support the hypothesis of Apremilast acting through the NF-κB-pathway and provide new insights into the interaction with fibroblast during intestinal wound healing.

HucMSC-Exo Promote Mucosal Healing in Experimental Colitis by Accelerating Intestinal Stem Cells and Epithelium Regeneration via Wnt Signaling Pathway.

Mucosal healing has emerged as a crucial therapeutic goal for inflammatory bowel diseases (IBD). Exosomes (Exo) as a potential acellular candidate for stem cell therapy might be competent to promote mucosal healing, while its mechanism remains unexplored. Exosomes derived from human umbilical cord mesenchymal stem cells (hucMSCs) were subjected to experimental colitis mice intraperitoneally to estimate the role in mucosal healing and the regeneration of intestinal stem cells (ISCs) and epithelium. The intestinal organoid model of IBD was constructed utilizing tumor necrosis factor (TNF)-α for subsequent function analysis in vitro. Transcriptome sequencing was performed to decipher the underlying mechanism and Wnt-C59, an oral Wnt inhibitor, was used to confirm that further. Finally, the potential specific components of hucMSC‑exo were investigated based on several existing miRNA expression datasets. HucMSC-exo showed striking potential for mucosal healing in colitis mice, characterized by decreased histopathological injuries and neutrophil infiltration as well as improved epithelial integrity. HucMSC-exo up-regulated the expression of leucine-rich repeat-containing G-protein coupled receptor 5 (Lgr5), a specific marker for ISCs and accelerated the proliferation of intestinal epithelium. HucMSC-exo endowed intestinal organoids with more excellent capacity to grow and bud under TNF-α stimulation. More than that, the fact that hucMSC-exo activated the canonical Wnt signaling pathway to promote mucosal healing was uncovered by not only RNA-sequencing but also relevant experimental data. Finally, bioinformatics analysis of the existing miRNA expression datasets indicated that several miRNAs abundant in hucMSC-exo involved widely in regeneration or repair related biological processes and Wnt signaling pathway might be one of the most important signal transduction pathways. Our results suggested that hucMSC-exo could facilitate mucosal healing in experimental colitis by accelerating ISCs and intestinal epithelium regeneration via transferring key miRNAs, which was dependent on the activation of Wnt/β-catenin signaling pathway.

An Improved Score for the Evaluation of Mucosal Healing in Inflammatory Bowel Disease-A Pilot Study.

Inflammatory bowel diseases are chronic conditions characterized by periods of remission, alternating with episodes of exacerbation, in which the primary therapeutic target is mucosal healing. Although colonoscopy is currently considered the gold standard for assessing disease activity, it presents a significant number of disadvantages. Over time, various inflammatory biomarkers have been proposed to detect disease activation, but current biomarkers have many limitations. Our study aimed to analyze the most commonly used biomarkers for patient monitoring and follow-up both independently and taken together as a group, in order to propose an improved activity score that more accurately reflects the changes occurring at the intestinal level, in order to limit the number of colonoscopic interventions. By applying logistic regression as a method of statistical analysis to the retrospectively collected data, we obtained an easy-to-calculate improved score that quantifies the chance that a given patient may be in remission or in a period of endoscopic activity. To achieve a widely accessible score that is easily accessible in clinical practice, we have included only the most commonly used clinical and biological parameters.

P648 Effectiveness of Biologic Therapies in Decreasing Risk of Hospitalization and Surgery, Maintaining Steroid Free Remission and Achieving Mucosal Healing in Inflammatory Bowel Disease; Real World Data.

Abstract Background Several biologic therapies are currently available for the management of inflammatory bowel disease (IBD) rendering the choice and sequencing between them as a first line under question. In our study, we evaluated the effectiveness of biologic therapies in achieving important clinical and endoscopic outcomes in biologic naïve patients with IBD. Methods Electronic medical records of patients with moderate to severe IBD, who were previously naïve to biologics, were reviewed and evaluated retrospectively in a tertiary care gastroenterology center, Haya Alhabib Center. Patients who were on infliximab, adalimumab, ustekinumab and vedolizumab for 12 months were included. The primary end points were percentage of hospitalization, surgery, steroid free remission, and mucosal healing, defined as Mayo score less than 1 in ulcerative colitis and SES-CD score less than 3 in Crohn’s disease. Descriptive analysis was performed to measure outcomes. Results A total of 335 biologic naïve patients with IBD were included; 262 (78.2%) patients with ulcerative colitis and 73 (21.8%) patients with Crohn’s disease. Regarding hospitalization, 25 (14.7%) out of 170 on adalimumab,12 (10.7%) out of 112 on infliximab, and one (6.25%) on vedolizumab were hospitalized. None of the patients on ustekinumab were hospitalized. 9 out of 171 (4.7%) patients on adalimumab underwent surgery, while none of the patients on the other biologics underwent IBD related surgery. Regarding steroid free remission, 29 (16.9%) out of 171 patients on adalimumab received steroid courses, 15 (13.3%) out of 113 patients on infliximab, 4 (11.4%) out of 35 patients on ustekinumab, and 1 (6.3%) out of 16 patients on vedolizumab. A total of 159 out of 171 patients (93.0%) on adalimumab achieved mucosal healing. While 100 out of 113 patients (88.5%) on infliximab, 26 out of 35 patients (74.3%) on ustekinumab, and 7 out of 16 patients (43.8%) on vedolizumab achieved mucosal healing. Conclusion Adalimumab, infliximab, and ustekinumab and vedolizumab were all effective in inducing steroid free remission. However, patients on vedolizumab had numerically lower percentages of mucosal healing than other biologics. Percentage of hospitalizations and IBD related surgeries were higher in patients on infliximab and adalimumab. Future Larger prospective comparative studies are needed.

EPITHELIAL CELLS OF ULCERATIVE COLITIS PATIENTS REQUIRE NORMAL LEVELS OF MITOCHONDRIA AND BETA-CATENIN TO UTILIZE BUTYRATE METABOLISM AND PROMOTE ULCER HEALING

Abstract BACKGROUND Under normal conditions butyrate produced by obligate anaerobes (e.g. firmicutes) provides the dominant energy source for colonocytes via β-oxidation and the tricarboxylic acid cycle. Ulcerative Colitis (UC) is an inflammatory bowel disease (IBD) characterized by reduced butyrate metabolism and intestinal epithelial cell (IEC) mitochondria (needed for β-oxidation). Given that nonhealing ulcers in UC are associated with reduced crypt fissioning and branching, we asked whether there was a relationship between mitochondrial deficiency and butyrate-induced crypt branching using colonoid cultures grown from human biopsies. METHODS IECs from biopsies taken from active and uninvolved areas of the same UC patient were grown in colonoid cultures. After the second passage, the colonoids with crypt branching were quantified. In separate studies, we modeled mitochondrial deficiency by shRNA knockdown of transcription mitochondrial factor A (Tfam) in human colonoids, a gene responsible for mitochondrial DNA stability and transcription. Both shControl and shTfam colonoids were treated with 5mM of Na-butyrate overnight. NCM460 cells were also treated with 5mM of butyrate overnight, and both ATP levels and TCF/LEF (b-catenin transcriptional activity) were examined. RESULTS Colonoids from active UC segments demonstrated 27% less crypt branching than uninvolved areas. These areas also displayed reduced mitochondria complex levels by WB of IEC. To directly examine the role of mitochondria in these effects, crypt branching was examined in shTFAM-treated colonoids where crypt branching levels were 31% less than shCont-treated colonoids (Fig. 1). Butyrate treatment of both shCont and shTfam colonoids increased crypt formation by 11% and 8%, respectively compared to untreated groups. In addition, butyrate increased levels of ATP by 55% and b-catenin transcriptional activity (TCF-LEF) by >600%. CONCLUSION This data was consistent with the notion that the failure to heal ulceration in UC patients involves both 1) reduction in butyrate availability from the microbiome (ie reduced stimulation) and 2) reduced mitochondria needed to metabolize butyrate. Upon effective anti-inflammatory treatment, we believe butyrate levels and IEC mitochondrial metabolism increase which contributes to IEC b-catenin signaling and enhanced crypt fissioning/branching needed for effective ulcer healing. We believe this data provide a potential mechanism for how enhanced mitochondrial function contributes to ulcer healing in IBD.