Multigene analysis unveils distinctive expression profiles of helper T-cell-related genes in the intestinal mucosa that discriminate between ulcerative colitis and Crohn's disease

Short noncoding RNAs as predictive biomarkers for the development from inflammatory bowel disease unclassified to Crohn's disease or ulcerative colitis

Numerous pathogenic processes are mediated by short noncoding RNAs (sncRNA). Twenty percent of inflammatory bowel disease (IBD) patients are labelled as IBD unclassified (IBDU) at disease onset. Most IBDU patients are reclassified as Crohn's disease (CD) or ulcerative colitis (UC) within few years. Since the therapeutic methods for CD and UC differ, biomarkers that can forecast the categorization of IBDU into CD or UC are highly desired. Here, we investigated whether sncRNAs can predict CD or UC among IBDU patients. 35 IBDU patients who were initially diagnosed with IBDU were included in this retrospective investigation; of them, 12, 15, and 8 were reclassified into CD (IBDU-CD), UC (IBDU-UC), or remained as IBDU (IBDU-IBDU), respectively. Eight IBD patients, were included as references. SncRNA profiling on RNA from mucosal biopsies were performed using Affymetrix miRNA 4.0 array. Selected probe sets were validated using RT-qPCR. Among all patients and only adults, 306 and 499 probe sets respectively were differentially expressed between IBDU-CD and IBDU-UC. Six of the probe sets were evaluated by RT-qPCR, of which miR-182-5p, miR-451a and ENSG00000239080 (snoU13) together with age and sex resulted in an AUC of 78.6% (95% CI: 60-97) in discriminating IBDU-CD from IBDU-UC. Based on the three sncRNAs profile it is possible to predict if IBDU patients within 3 years will be reclassified as CD or UC. We showed that the expression profile of IBDU patients differ from that of definite CD or UC, suggesting that a subgroup of IBDU patients may compose a third unique IBD subtype.

The Metabolites of Lactobacillus fermentum F-B9-1 Relieved Dextran Sulfate Sodium-Induced Experimental Ulcerative Colitis in Mice

Because of the increased incidence and prevalence, ulcerative colitis (UC) has become a global health issue in the world. Current therapies for UC are not totally effective which result in persistent and recurrent symptom of many patients. Lactobacillus with anti-inflammatory effects might be beneficial to the prevention or treatment for UC. Here, we examined the ameliorative effects of the metabolites of Lactobacillus fermentum F-B9-1 (MLF) in Caco-2 cells and dextran sodium sulfate (DSS)-induced UC model mice. MLF displayed intestinal barrier-protective activities in Caco-2 cells by increasing the expression of Occludin and ZO-1. They also showed anti-inflammatory potential in interleukin (IL)-1β and IL-6. In order to further examine the in vivo anti-inflammatory effect of MLF, the MLF was gavaged in the DSS-induced UC model mice. The intragastric administration of MLF effectively alleviated colitis symptoms of weight loss, diarrhea, colon shortening, and histopathological scores, protected intestinal barrier function by increasing Occludin and ZO-1, and attenuated colonic and systemic inflammation by suppressing production of IL-1β and IL-6. Finally, the use of MLF remodeled the diversity of the gut microbiota and increased the number of beneficial microorganisms. Overall, the results demonstrated that MLF relieved DSS-induced UC in mice. And MLF might be an effective therapy method to UC in the clinic in the future.

Molecular and Histological Profiling Reveals an Innate-Shaped Immune Microenvironment in Solitary Juvenile Polyps

INTRODUCTION

Solitary juvenile polyps (JP) are characterized by a benign disease course with low recurrence rate but present with signs of intestinal inflammation. To better understand the underlying pathogenesis, we performed histological and molecular evaluation targeting distinct immune mechanisms.

METHODS

Pediatric patients with JP (n = 12), with treatment-naïve inflammatory bowel disease (IBD; [n = 41]) as inflammatory control, and non-IBD controls (n = 14) were investigated. For a comparative analysis of infiltrating immune cells, a next-generation tissue microarray of biopsies was assembled, immunostained, and scored. Targeted transcriptional profiling was performed using a customized immunology panel.

RESULTS

In JP, a predominant accumulation of neutrophils and eosinophils was observed. RNA expression profiles revealed increased levels of CXCL8, CXCL5, and CCL11 transcripts in JP, indicating an enhanced recruitment of neutrophils and eosinophils. Moreover, messenger RNA levels of the proinflammatory cytokine IL1b and the inflammation-amplifying receptor TREM1 were higher in JP, whereas we could not find signs of a functionally polarized Tcell response in JP when compared with IBD.

DISCUSSION

Patients with JP and patients with treatment-naïve IBD have distinct cell infiltrates during active disease. The ample presence of eosinophils in JP supports neutrophil accumulation, which is responsible for the elevated release of calprotectin. Intriguingly, however, we were not able to identify a functionally polarized T-cell response in JP, which indicates that during the acute onset of inflammation in JP, a potent adaptive immune memory is not established. This may explain the low reoccurrence rate of JP.

Discriminant equation using mucosally expressed cytokines and transcription factor for making definite diagnosis of inflammatory bowel disease unclassified

Background

The pathological conditions of UC and CD involved in inflammatory bowel disease-unclassified (IBD-U), UC with primary sclerosing cholangitis (PSC-UC), and UC with autoimmune pancreatitis type 2 (AIP-UC) remain unclear. Therefore, it is difficult to decide the appropriate treatments for these subtypes of UC. Our aim was to examine whether the discriminant equation using the mucosally expressed mediators designed as our previous study for IBD, could characterize IBD-U, PSC-UC, or AIP-UC.

Methods

A total of 56 patients including UC (n = 24), CD (n = 15), IBD-U (n = 10), PSC-UC (n = 4), and AIP-UC (n = 3), along with 9 control patients were enrolled in this study. Mucosally expressed inflammatory mediators related to Th1, Th2, Th17, and Treg were measured using quantitative PCR in endoscopic biopsies from the inflamed intestines of the patients. The IBD-U, PSC-UC or AIP-UC were characterized using discriminant analysis and principle component analysis.

Results

Through discriminant analyses, combinations of 3 to 7 inflammatory mediators were used to discriminate between UC and CD. Moreover, the identified 3 markers could diagnose patients with IBD-U as UC or CD with high accuracy. The distribution graph of inflammatory mediators using the principal component analysis revealed that PSC-UC and AIP-UC exhibited CD-like and UC-like features, respectively.

Conclusions

The discriminant equation using mucosally expressed mediators of IL-13, IL-21 and T-bet can be used as a universal diagnostic tool not only for IBD-U but also to assess pathological conditions in PSC-UC and AIP-UC.

Role of the IL-23-T-bet/GATA3 Axis for the Pathogenesis of Ulcerative Colitis

Ulcerative colitis (UC) has been considered a Th2- and Th17-related disease. However, anti-IL-12/23 p40 antibody, which blocks Th1 and Th17 cell induction and maintenance, has shown efficacy in treating UC, suggesting that UC might not be a prototypical Th2 and Th17 cell-mediated autoimmune disease. To verify how the immune responses in UC patients interact with each other, we analyzed the cytokine expression and transcription factors involved in the Th1, Th2, and Th17 responses. The mucosal expression of 19 cytokines and transcription factors related to Th1, Th2, and Th17 cells, as well as Tregs, were measured by quantitative polymerase chain reaction using endoscopic biopsy specimens from inflamed colons of UC patients. A correlation analysis between the cytokines and transcription factors was conducted. The characteristic cytokine profile in UC patients has two immune response clusters: Th17-related responses and Th1-/Th2-related responses. IL-23 showed a weaker association with Th17 cell-related cytokines and transcription factor RORC and a much stronger correlation with T-bet and GATA3. In the high-IL-23-expression group, the rate of chronic continuous type was higher and the remission rate lower than in the low-IL-23-expression group. IL-23 may be a very important cytokine for evaluating the UC disease condition, as the expression of IL-23 is associated with certain clinical characteristics of UC patients. A unique association between IL-23 and T-bet/GATA3 might play a key role in the pathogenesis of UC.

Interplay between Cytokine Circuitry and Transcriptional Regulation Shaping Helper T Cell Pathogenicity and Plasticity in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic disorder manifested as Crohn’s disease (CD) and ulcerative colitis (UC) characterized by intestinal inflammation and involves a dysregulated immune response against commensal microbiota through the activation of CD4 T helper cells. T helper cell differentiation to effector or regulatory phenotypes is controlled by cytokine networks and transcriptional regulators. Distinct polarized T helper cells are able to alter their phenotypes to adapt to diverse and fluctuating physiological environments. T helper cells exhibit intrinsic instability and flexibility to express cytokines of other lineages or transdifferentiate from one T helper cell type to another in response to various perturbations from physiological cytokine milieu as a means of promoting local immunity in response to injury or ensure tissue homeostasis. Furthermore, functional plasticity and diversity of T helper cells are associated with pathogenicity and are critical for immune homeostasis and prevention of autoimmunity. In this review, we provide deeper insights into the combinatorial extrinsic and intrinsic signals that control plasticity and transdifferentiation of T helper cells and also highlight the potential of exploiting the genetic reprogramming plasticity of T helper cells in the treatment of IBD.

I_MDS: an inflammatory bowel disease molecular activity score to classify patients with differing disease-driving pathways and therapeutic response to anti-TNF treatment

Crohn’s disease and ulcerative colitis are driven by both common and distinct underlying mechanisms of pathobiology. Both diseases, exhibit heterogeneity underscored by the variable clinical responses to therapeutic interventions.

We aimed to identify disease-driving pathways and classify individuals into subpopulations that differ in their pathobiology and response to treatment.

We applied hierarchical clustering of enrichment scores derived from gene set variation analysis of signatures representative of various immunological processes and activated cell types, to a colonic biopsy dataset that included healthy volunteers, Crohn’s disease and ulcerative colitis patients. Patient stratification at baseline or after anti-TNF treatment in clinical responders and non-responders was queried. Signatures with significantly different enrichment scores were identified using a general linear model. Comparisons to healthy controls were made at baseline in all participants and then separately in responders and non-responders. Fifty-nine percent of the signatures were commonly enriched in both conditions at baseline, supporting the notion of a disease continuum within ulcerative colitis and Crohn’s disease. Signatures included T cells, macrophages, neutrophil activation and poly:IC signatures, representing acute inflammation and a complex mix of potential disease-driving biology. Collectively, identification of significantly enriched signatures allowed establishment of an inflammatory bowel disease molecular activity score which uses biopsy transcriptomics as a surrogate marker to accurately track disease severity. This score separated diseased from healthy samples, enabled discrimination of clinical responders and non-responders at baseline with 100% specificity and 78.8% sensitivity, and was validated in an independent data set that showed comparable classification. Comparing responders and non-responders separately at baseline to controls, 43% and 70% of signatures were enriched, respectively, suggesting greater molecular dysregulation in TNF non-responders at baseline. This methodological approach could facilitate better targeted design of clinical studies to test therapeutics, concentrating on patient subsets sharing similar underlying pathobiology, therefore increasing the likelihood of clinical response.

Patients exhibiting similar phenotypical characteristics, diagnosed with the same disease, exhibit variable response to therapeutics. This is a major health care issue, due to the increased patient suffering and the socioeconomical burden that occurs. Crohn’s disease and ulcerative colitis constitute good examples of inflammatory conditions, with sufferers responding differentially to existent therapeutics. Here, we identified disease-driving pathways and classified individuals into subpopulations that differ in their pathobiology and response to treatment. We utilized gene set variation analysis and transcriptomic data from inflammatory bowel disease sufferers to stratify patients at baseline or after anti-TNF treatment in clinical responders and non-responders. We explored gene signatures obtained from the literature, relevant to immune processes, which were significantly enriched in disease compared to healthy controls, as well as before and after treatment. Using these signatures, we established an inflammatory bowel disease molecular activity score, which allowed us to separate clinical responders and non-responders at baseline with high specificity and sensitivity. We validated the proposed approach in an independent data set, demonstrating comparable classification. This methodological approach may lead to better targeted design of clinical studies, allowing the selection of patient sharing similar underlying pathobiology, thus increasing the likelihood of clinical response to treatment.

A molecular biomarker for prediction of clinical outcome in children with ASD, constipation, and intestinal inflammation

In children with autism spectrum disorder (ASD) who present to the gastroenterologist with chronic constipation on a background of colonic inflammation, we have identified two distinct clinical subtypes: (1) patients who experience a sustained state of GI symptomatic remission while on maintenance anti-inflammatory therapy (fast responders) and, (2) those with recurrent right-sided fecal loading requiring regular colon cleanouts during treatment for enterocolitis (slow responders). We hypothesized that a detailed molecular analysis of tissue from the affected region of the colon would provide mechanistic insights regarding the fast versus slow response to anti-inflammatory therapy. To test this, ascending colon biopsy tissues from 35 children with ASD (20 slow responders and 15 fast responders) were analyzed by RNAseq. Hierarchical cluster analysis was performed to assign samples to clusters and gene expression analysis was performed to identify differentially expressed transcripts (DETs) between samples within the clusters. Significant differences were found between the two clusters with fast responder-predominant cluster showing an upregulation of transcripts involved in the activation of immune and inflammatory response and the slow responder-predominant cluster showing significant over-representation of pathways impacting colonic motility (e.g. genes involved in tryptophan and serotonin degradation and mitochondrial dysfunction). Regression analysis identified a single long non-coding RNA that could predict cluster assignment with a high specificity (0.88), sensitivity (0.89) and accuracy (0.89). Comparison of gene expression profiles in the ascending colon from a subset of patients with ASD, chronic right-sided fecal loading constipation and a slow versus fast response to therapy has identified molecular mechanisms that likely contribute to this differential response following the primary therapeutic intervention (i.e. treatment for colonic inflammation with brief induction immunosuppression followed by maintenance non-steroidal anti-inflammatory therapy). Importantly, we have identified a transcript that, if validated, may provide a biomarker that can predict from the outset which patients will be slow responders who would benefit from an alternate therapeutic strategy in treating their constipation.

Mucosally Expressed Cytokines are Associated with the Esophageal Motility Function

BACKGROUND AND AIM

Although basic research has shown that certain cytokines affect gastrointestinal motility, the clinical evidence is lacking. The objective of this study was to explore the association between mucosally expressed cytokines and the esophageal motility function in humans.

METHODS

We enrolled a total of 57 patients with suspected esophageal motility disorders (EMDs) who underwent high-resolution manometry.

RESULTS

The diagnoses of the patients were as follows: normal esophageal motility (n = 25), ineffective esophageal motility (n = 5), esophagogastric junction outflow obstruction (EGJOO; n = 10), distal esophageal spasm (n = 5), achalasia (n = 10), absent contractility (n = 1), and jackhammer esophagus (n = 1). The expression of tumor necrosis factor (TNF)-α in the esophagogastric junction (EGJ) was significantly higher in EGJOO (14.6, 14.0-15.8, n = 10) than in normal esophageal motility (13.3, 12.8-14.1, n = 25); however, there was no difference in the expression of TNF-α between achalasia (13.4, 13.0-14.1, n = 10) and normal esophageal motility (13.3, 12.8-14.1, n = 25). EGJOO was discriminated from achalasia/normal by a linear discriminant analysis (AUC = 0.917). A multivariable regression analysis revealed that interleukin (IL)-13 and IL-23A were predictive of the distal contractile integral, whereas TNF-α and IL-6 were predictive of the basal EGJ pressure.

CONCLUSIONS

The esophageal motility was associated with mucosally expressed cytokines in humans; these cytokines could be useful targets for the diagnosis and treatment of EMDs.

Diagnostic Potential of Systemic Eosinophil-Associated Cytokines and Growth Factors in IBD

Despite the acknowledged contribution of eosinophils to the disease pathogenesis, available data on cytokines closely related to the peripheral eosinophils in inflammatory bowel disease (IBD) are scattered. We assessed the concentrations of eosinophil-associated cytokines and growth factors in the group of 277 individuals (101 patients with Crohn's disease (CD), 77 with ulcerative colitis (UC), 16 with irritable bowel syndrome (IBS), and 83 healthy controls) and referred to IBD activity and the levels of hsCRP. As compared to IBS patients or healthy controls, patients with CD had significantly higher levels of IL5, IL8, IL12(p70), GM-CSF, and TNFα and patients with UC, the levels of eotaxin, IL4, IL5, IL8, IL12(p70), IL13, GM-CSF, and TNFα were also higher. As compared to CD patients, patients with UC had significantly higher levels of eotaxin, IL4, IL5, IL8, and IL1. In turn, the concentrations of hsCRP were significantly higher in CD than UC. Except for IL13, all cytokines and hsCRP positively correlated with CDAI. In UC, a positive correlation with MDAI was observed for hsCRP, GM-CSF, IL12(p70), and IFNγ and a negative one for IL8. The concentrations of hsCRP, GM-CSF, IFNγ, IL12(p70), and RANTES were higher in UC patients with active than inactive disease whereas those of IL8 and TNFα were significantly lower. Eotaxin, determined individually or in a panel with IFNγ and hsCRP, showed fair accuracy in differentiating CD from UC. If confirmed on a larger representation of IBS patients, IL8 might support differential diagnosis of organic and functional conditions of the bowel. GM-CSF, in turn, demonstrated to be an excellent indicator of bowel inflammation and may be taken into consideration as a noninvasive marker of mucosal healing. In summary, eosinophil-associated cytokines are elevated in IBD, more pronouncedly in UC, and may support the differential diagnosis of IBD and aid in monitoring of mucosal healing.

Dietary quercetin ameliorates experimental colitis in mouse by remodeling the function of colonic macrophages via a heme oxygenase-1-dependent pathway

Inflammatory bowel disease (IBD) results from a chronic intestinal inflammation and tissue destruction via an aberrant immune-driven inflammatory response towards an altered gut microbiota. Dietary intervention is becoming an attractive avenue for the therapy of colitis because diet is a key determinant of the mucosal immune response. Quercetin (QCN) is the most common in nature and the major representative of dietary antioxidant flavonoids, which has been demonstrated to influence the progression of colitis. However, the underlying mechanism of QCN on intestinal immunomodulation remains unclear. Here, our study demonstrated dietary QCN could ameliorate experimental colitis in part by modulating the anti-inflammatory effects and bactericidal capacity of macrophages via Heme oxygenase-1 (Hmox1, HO-1) dependent pathway. It suggested that QCN might restore the proper intestinal host-microbe relationship to ameliorate the colitis via rebalancing the pro-inflammatory, anti-inflammatory and bactericidal function of enteric macrophages. Hence, modulating the function of intestinal macrophages with dietary administration of QCN to restore the immunological hemostasis and rebalance the enteric commensal flora is a potential and promising strategy for IBD therapy.

Indigo Naturalis Ameliorates Oxazolone-Induced Dermatitis but Aggravates Colitis by Changing the Composition of Gut Microflora

BACKGROUND

Indigo naturalis (IND) is an herbal medicine that has been used as an anti-inflammatory agent to treat diseases including dermatitis and inflammatory bowel disease in China. However, the mechanism by which IND exerts its immunomodulatory effect is not well understood.

METHODS

A murine model of dermatitis and inflammatory bowel disease, both induced by oxazolone (OXA), was treated with IND. The severity of dermatitis was evaluated based on ear thickness measurements and histological scoring. The severity of colitis was evaluated by measuring body weight, histological scoring, and endoscopic scoring. The expression of inflammatory cytokines in ear and colon tissue was evaluated using real-time PCR. 16S rRNA DNA sequencing of feces from OXA-induced colitis mice was performed before and after IND treatment. The effects of IND on OXA-induced colitis were also evaluated after depleting the gut flora with antibiotics to test whether alteration of the gut flora by IND influenced the course of intestinal inflammation in this model.

RESULTS

IND treatment ameliorated OXA dermatitis with a reduction in IL-4 and eosinophil recruitment. However, OXA colitis was significantly aggravated in spite of a reduction in intestinal IL-13, a pivotal cytokine in the induction of the colitis. It was found that IND dramatically altered the gut flora and IND no longer exacerbated colitis when colitis was induced after gut flora depletion.

CONCLUSIONS

Our data suggest that IND could modify the inflammatory immune response in multiple ways, either directly (i.e., modification of the allergic immune cell activity) or indirectly (i.e., alteration of commensal compositions).

Increased IL-17A/IL-17F expression ratio represents the key mucosal T helper/regulatory cell-related gene signature paralleling disease activity in ulcerative colitis

BACKGROUND

T helper (T_h) and regulatory T (T_reg) cell-related cytokines are implicated in inflammatory bowel diseases, including ulcerative colitis (UC). While these cytokines are generally upregulated in inflamed mucosae, the key cytokine profile explaining disease severity has not been determined.

METHODS

The Rachmilewitz endoscopic index (REI) was assessed in 61 UC patients undergoing colonoscopy. Biopsies obtained from inflamed (REI 3-12) and noninflamed (REI 0-2) areas were analyzed by quantitative PCR for expression of mRNAs encoding cytokines and transcription factors related to Th1 (TNF-α, IFN-γ, IL-12p35, IL-12p40, and T-bet), Th2 (IL-4, IL-13, IL-33, and GATA3), Th17 (IL-17A, IL-17F, IL-21, IL-22, IL-23p19, IL-6, and RORC), Th9 (IL-9, IRF4, and PU.1), and Treg (TGF-β and Foxp3). Expression patterns associated with higher REI were determined by univariate and multivariate analyses.

RESULTS

Despite general upregulation, none of these mRNAs showed univariate correlation with REI in inflamed samples. Multiple regression analysis, however, found that joint expression of IL-17A, IL-17F, IL-21, RORC, and TGF-β was significantly predictive of REI (P < 0.0002, R² = 0.380), with major individual contributions by IL-17A (P < 0.0001) and IL-17F (P < 0.0001), which were associated with increased and decreased REI, respectively. Partial correlation analysis, validating this model, indicated differences between IL-17A and IL-17F in correlating with other targets. The IL-17A/IL-17F ratio showed a significant correlation with REI (r = 0.5124, P < 0.0001), whereas no other mRNAs were essentially predictive of REI.

CONCLUSIONS

Mucosal IL-17A/IL-17F ratio significantly correlates with endoscopic score in UC patients, accompanied by their disparate interactions with other T_h/T_reg-related genes.

The Role of T-Cell Subsets in Chronic Inflammation in Celiac Disease and Inflammatory Bowel Disease Patients: More Common Mechanisms or More Differences?

Background

Chronic intestinal inflammation due to noninfectious causes represents a growing health issue all over the world. Celiac disease as well as inflammatory bowel diseases (IBD) like Crohn's disease and ulcerative and microscopic colitis involve uncontrolled T-cell activation and T-cell-mediated damage as common denominators. Therefore, diagnosis and treatment decisions clearly benefit from the knowledge of the intricacies of the systemic and the local T-cell activity.

Summary

Depending on the cytokine milieu, CD4⁺ T cells can differentiate into proinflammatory T helper 1 (Th1), anti-inflammatory Th2, antimicrobial Th17, pleiotropic Th9, tissue-instructing Th22 cells, and in the regulatory compartment forkhead box protein 3⁺ Treg, suppressive Tr1 or Th3 cells. Additionally, follicular Th cells provide B-cell help in antibody class switching; cytotoxic CD8⁺ T cells target virus-infected or tumor cells. This review discusses our current knowledge on the contribution of defined T-cell subpopulations to establishing and maintaining chronic intestinal inflammation in either of the above entities. It also puts emphasis on the differences in the prevalence of these diseases between Eastern and Western countries.

Key Messages

In celiac disease, the driving role of T cells in the lamina propria and in the epithelium mainly specific for two defined antigens is well established. Differences in genetics and lifestyle between Western and Eastern countries were instrumental in understanding underlying mechanisms. In IBD, the vast amount of potential antigens and the corresponding antigen-specific T cells makes it unlikely to find universal triggers. Increased mucosal CD4⁺ regulatory T cells in all four entities fail to control or abrogate local inflammatory processes. Thus, prevailing differences in the functional T-cell subtypes driving chronic intestinal inflammation in celiac disease and IBD at best allow some overlap in the treatment options for either disease.

Up-regulation of the human-specific CHRFAM7A gene in inflammatory bowel disease

Background: The α7-subunit of the α7-nicotinic acetylcholine receptor (α7-nAChR) is an obligatory intermediate for the anti-inflammatory effects of the vagus nerve. But in humans, there exists a second gene called CHRFAM7A that encodes a dominant negative α7-nAChR inhibitor. Here, we investigated whether their expression was altered in inflammatory bowel disease (IBD) and colon cancer.

Methods: Quantitative RT-PCR measured gene expression of human α7-nAChR gene (CHRNA7), CHRFAM7A, TBC3D1, and actin in biopsies of normal large and small intestine, and compared to their expression in biopsies of ulcerative colitis, Crohn's disease, and colon cancer.

Results: qRT-PCR showed that CHRFAM7A and CHRNA7 gene expression was significantly (p < .02) up-regulated in IBD (N = 64). Gene expression was unchanged in colon cancer. Further analyses revealed that there were differences in ulcerative colitis and Crohn's Disease. Colon biopsies of ulcerative colitis (N = 33) confirmed increased expression of CHRFAM7A and decreased in CHRNA7 expression (p < 0.001). Biopsies of Crohn's disease (N = 31), however, showed only small changes in CHRFAM7A expression (p < 0.04) and no change in CHRNA7. When segregated by tissue source, both CHRFAM7A up-regulation (p < 0.02) and CHRNA7 down-regulation (p < 0.001) were measured in colon, but not in small intestine.

Conclusion: The human-specific CHRFAM7A gene is up-regulated, and its target, CHRNA7, down-regulated, in IBD. Differences between ulcerative colitis and Crohn's disease tie to location of disease.

Significance: The appearance of IBD in modern humans may be consequent to the emergence of CHRFAM7A, a human-specific α7-nAChR antagonist. CHRFAM7A could present a new, unrecognized target for development of IBD therapeutics.

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CHRFAM7A is a pro-inflammatory and human-specific gene not found in other species.

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CHRFAM7A expression is elevated in certain IBD, but its target CHRNA7 decreased.

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Changes in CHRFAM7A and CHRNA7 expression are disease- and tissue site specific.

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Some IBDs may be examples of “off-target disease sequelae” of human evolution.

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Animal modeling of human disease do not test contributions of human-specific genes.

Characterization of Serum Cytokine Profile in Predominantly Colonic Inflammatory Bowel Disease to Delineate Ulcerative and Crohn's Colitides

BACKGROUND

As accessible diagnostic approaches fail to differentiate between ulcerative colitis (UC) and Crohn’s colitis (CC) in one-third of patients with predominantly colonic inflammatory bowel disease (IBD), leading to inappropriate therapy, we aim to investigate the serum cytokine levels in these patients in search of molecular biometric markers delineating UC from CC.

METHODS

We measured 38 cytokines, chemokines, and growth factors using magnetic-bead-based multiplex immunoassay in 25 UC patients, 28 CC patients, and 30 controls. Our results are compared with those from a review of current literature regarding advances in serum cytokine profiles and associated challenges preventing their use for diagnostic/prognostic purposes.

RESULTS

Univariate analysis showed statistically significant increases of eotaxin, GRO, and TNF-α in UC patients compared to controls (Ctrl); interferon γ, interleukin (IL)-6, and IL-7 in CC group compared to Ctrl; and IL-8 in both UC and CC versus Ctrl. No cytokines were found to be different between UC and CC. A generalized linear model identified combinations of cytokines, allowing the identification of UC and CC patients, with area under the curve (AUC) = 0.936, as determined with receiver operating characteristic (ROC) analysis.

CONCLUSIONS

The current knowledge available about circulating cytokines in IBD is often contradictory. The development of an evidence-based tool using cytokines for diagnostic accuracy is still preliminary.