Single Nucleotide Polymorphisms in Selected Genes in Inflammatory Bowel Disease

The Effect of Serotonin Transmission on Depressive and Insomnia Symptoms in Inflammatory Bowel Diseases

The serotonergic pathway may impact the pathogenesis and the course of inflammatory bowel diseases (IBDs). The aim of this study was to investigate the relationship between 5-HT, the serotonin transporter (SERT), and the clinical course of the disease with the occurrence of sleep and mood disorders. Participants completed sleep questionnaires and the Beck Depression Inventory (BDI). Serum 5-HT, SERT protein expression, and mRNA levels were quantified. Additionally, patients treated with anti-TNF therapy were examined before and after treatment. In this study, 77 patients with IBD and 41 healthy controls (HCs) were enrolled and 24 of them were treated with anti-TNF therapy. Patients with IBD had higher 5-HT levels and SERT protein expression than the HCs, but not mRNA SERT levels (p = 0.015, p = 0.001, p = 0.069, respectively). Similar results were obtained for patients in the active state of the disease compared to the non-active state. There was a positive relationship between insomnia severity and SERT protein expression. BDI did not correlate with serotonin or SERT. After anti-TNF therapy, only 5-HT levels were decreased. 5-HT and SERT protein are overexpressed in active IBD and may represent a candidate for novel disease activity biomarkers. The correlation between the SERT protein level and the severity of insomnia symptoms might be among the underlying biochemical factors of sleep disturbances. Anti-TNF treatment might contribute to the reduction in 5-HT levels.

Protective role of flavonoids quercetin and silymarin in the viral-associated inflammatory bowel disease: an updated review

Inflammatory bowel disease (IBD) is a chronic recurrent inflammation of the gastrointestinal tract (GIT). IBD patients are susceptible to various infections such as viral infections due to the long-term consumption of immunosuppressive drugs and biologics. The antiviral and IBD protective traits of flavonoids have not been entirely investigated. This study objective included an overview of the protective role of flavonoids quercetin and silymarin in viral-associated IBD. Several viral agents such as cytomegalovirus (CMV), Epstein-Barr virus (EBV), varicella zoster virus (VZV) and enteric viruses can be reactivated and thus develop or exacerbate the IBD conditions or eventually facilitate the disease remission. Flavonoids such as quercetin and silymarin are non-toxic and safe bioactive compounds with remarkable anti-oxidant, anti-inflammatory and anti-viral effects. Mechanisms of anti-inflammatory and antiviral effects of silymarin and quercetin mainly include immune modulation and inhibition of caspase enzymes, viral binding and replication, RNA synthesis, viral proteases and viral assembly. In the nutraceutical sector, natural flavonoids low bioavailability and solubility necessitate the application of delivery systems to enhance their efficacy. This review study provided an updated understanding of the protective role of quercetin and silymarin against viral-associated IBD.

Association between inflammatory bowel diseases and Parkinson's disease: systematic review and meta-analysis

Growing evidence suggests that there are similar pathological mechanisms and closely related pathogenic risk factors for inflammatory bowel disease (IBD) and Parkinson's disease (PD). However, the epidemiological features of these two diseases are different. This review systematically evaluated the relationship between inflammatory bowel diseases and Parkinson's disease risk. We searched PubMed, Embase, and Cochrane databases to retrieve observational studies of IBD and PD published from inception to October 2019. Nine observational studies, involving 12,177,520 patients, were included in the final analysis. None of the studies had Newcastle–Ottawa Scale scores that suggested a high risk of bias. After adjusting for confounders and excluding heterogeneous studies, the overall risk of PD was significantly higher in IBD patients than in the general population (adjusted risk ratio [RR] = 1.24, 95% confidence interval [CI]: 1.15–1.34, P < 0.001). A meta-analysis of the temporal relationship revealed that the incidence of IBD was significantly increased before (adjusted hazard ratio [HR] = 1.26, 95% CI: 1.18–1.35, P < 0.001) and after (adjusted RR = 1.40, 95% CI: 1.20–1.80, P < 0.001) PD diagnosis. After excluding a heterogeneous study, the pooled risk of PD development in patients with ulcerative colitis (adjusted HR = 1.25, 95% CI: 1.13–1.38, P < 0.001) or Crohn's disease (adjusted HR = 1.33, 95% CI: 1.21–1.45, P < 0.01) was significantly increased. Subgroup analysis revealed no significant differences in risk between men (adjusted HR = 1.23, 95% CI: 1.10–1.39) and women (adjusted HR = 1.26, 95% CI: 1.10–1.43); however, older (> 65 years old) IBD patients (adjusted HR = 1.32, 95% CI: 1.17–1.48) may have a higher risk than younger (≤ 65 years old) patients (adjusted HR = 1.24, 95% CI: 1.08–1.42). Patients with IBD who were not treated with anti-tumor necrosis factor-α or azathioprine had significantly higher PD risk (adjusted HR = 1.6, 95% CI: 1.2–2.2). Thus, our meta-analysis indicates a certain correlation between IBD and PD, and suggests that IBD may moderately increase PD risk regardless of sex, especially in patients over 65 years of age. Moreover, early anti-inflammatory therapies for IBD might reduce the risk of developing PD. Our findings suggest an urgent need for an individualized screening strategy for patients with IBD. However, most studies included in this paper were observational, and more randomized controlled trials are needed to confirm the precise association between IBD and PD.

Influence of the Treatment Used in Inflammatory Bowel Disease on the Protease Activities

Introduction

There is growing evidence that intestinal proteases have a role in the pathogenesis of gastrointestinal inflammatory diseases. Inflammatory bowel disease (IBD), which includes Crohn’s disease (CD) and ulcerative colitis (UC), has an additional source of proteases represented by infiltrated and activated inflammatory cells. The aim of our study was to determine proteolytic system activity in patients with CD and UC. We limited the number of proteases tested by determining proteases active in acidic, neutral and alkaline pH.

Materials and Methods

The study included 40 patients with IBD – 20 CD patients and 20 UC patients. The control group consisted of 20 healthy subjects. Among the 20 CD patients, 17 were treated with aminosalicylates, 14 with azathioprine, and 4 with corticosteroids, while 8 patients were undergoing biological treatment. Among the 20 UC patients, 19 were treated with aminosalicylates, 8 with azathioprine, and 3 with corticosteroids. The total protein concentration was assayed by the Lowry method. The optimal pH was assayed in pH from 2.2 to 12.8, separated by 0.2 intervals. Proteolytic activities were determined against different substrates (gelatine, haemoglobin, ovalbumin, albumin, cytochrome C, and casein), and haemoglobin was the optimal substrate. Protease activities were determined according to Anson method. Determination of the activities of natural inhibitors of acidic, neutral and alkaline proteases is based on the Lee and Lin method.

Results

Decreases were observed in the activities of acid proteases (pH 5), alkaline proteases (pH 7), and neutral proteases (pH 7.6 and 8.6) in the groups of CD patients in remission in comparison with the active phase. In the group of patients with biologically treated CD patients, acid protease activity (pH 5.0) was lower than in CD patients not receiving biological treatment. Activities of neutral (pH 7.0) and alkaline (pH 7.6 and 8.6) proteases in the plasma of patients with UC in remission were lower in comparison to the active phase. Activities of acid (pH 5.0) and alkaline (8.6) protease inhibitors were higher in CD patients in the active phase in comparison to remission. In UC patients with exacerbation of the disease, the activity of alkaline (pH 8.6) protease inhibitors was increased compared to remission.

Conclusion

1. Our research may suggest that the immunomodulatory treatment used in IBD, aimed at reducing the level of leukocytes and reduction of inflammation, may contribute to a reduction in protease activity. 2. The decrease of protease activities in patients with CD and UC in remission may be a marker suggesting the patients’ response to the treatment.

Inflammatory bowel disease: Therapeutic limitations and prospective of the stem cell therapy

Inflammatory bowel disease (IBD), consisting primarily of ulcerative colitis and Crohn’s disease, is a group of debilitating auto-immune disorders, which also increases the risk of colitis-associated cancer. However, due to the chronic nature of the disease and inconsistent treatment outcomes of current anti-IBD drugs (e.g., approximately 30% non-responders to anti-TNFα agents), and related serious side effects, about half of all IBD patients (in millions) turn to alternative treatment options. In this regard, mucosal healing is gaining acceptance as a measure of disease activity in IBD patients as recent studies have correlated the success of mucosal healing with improved prognosis. However, despite the increasing clinical realization of the significance of the concept of mucosal healing, its regulation and means of therapeutic targeting remain largely unclear. Here, stem-cell therapy, which uses hematopoietic stem cells or mesenchymal stem cells, remains a promising option. Stem cells are the pluripotent cells with ability to differentiate into the epithelial and/or immune-modulatory cells. The over-reaching concept is that the stem cells can migrate to the damaged areas of the intestine to provide curative help in the mucosal healing process. Moreover, by differentiating into the mature intestinal epithelial cells, the stem cells also help in restoring the barrier integrity of the intestinal lining and hence prevent the immunomodulatory induction, the root cause of the IBD. In this article, we elaborate upon the current status of the clinical management of IBD and potential role of the stem cell therapy in improving IBD therapy and patient’s quality of life.

Increased expression of kynurenine aminotransferases mRNA in lymphocytes of patients with inflammatory bowel disease

BACKGROUND

Complex interaction of genetic defects with environmental factors seems to play a substantial role in the pathogenesis of inflammatory bowel disease (IBD). Accumulating data implicate a potential role of disturbed tryptophan metabolism in IBD. Kynurenic acid (KYNA), a derivative of tryptophan (TRP) along the kynurenine (KYN) pathway, displays cytoprotective and immunomodulating properties, whereas 3-OH-KYN is a cytotoxic compound, generating free radicals.

METHODS

The expression of lymphocytic mRNA encoding enzymes synthesizing KYNA (KAT I-III) and serum levels of TRP and its metabolites were evaluated in 55 patients with IBD, during remission or relapse [27 patients with ulcerative colitis (UC) and 28 patients with Crohn's disease (CD)] and in 50 control individuals.

RESULTS

The increased expression of KAT1 and KAT3 mRNA characterized the entire cohorts of patients with UC and CD, as well as relapse-remission subsets. Expression of KAT2 mRNA was enhanced in patients with UC and in patients with CD in remission. In the entire cohorts of UC or CD, TRP levels were lower, whereas KYN, KYNA and 3-OH-KYN were not altered. When analysed in subsets of patients with UC and CD (active phase-remission), KYNA level was significantly lower during remission than relapse, yet not versus control. Functionally, in the whole groups of patients with UC or CD, the TRP/KYN ratio has been lower than control, whereas KYN/KYNA and KYNA/3-OH-KYN ratios were not altered. The ratio KYN/3-OH-KYN increased approximately two-fold among all patients with CD; furthermore, patients with CD with relapse, manifested a significantly higher KYNA/3-OH-KYN ratio than patients in remission.

CONCLUSION

The presented data indicate that IBD is associated with an enhanced expression of genes encoding KYNA biosynthetic enzymes in lymphocytes; however, additional mechanisms appear to influence KYNA levels. Higher metabolic conversion of serum TRP in IBD seems to be followed by the functional shift of KYN pathway towards the arm producing KYNA during exacerbation. We propose that KYNA, possibly via interaction with aryl hydrocarbon receptor or G-protein-coupled orphan receptor 35, may serve as a counter-regulatory mechanism, decreasing cytotoxicity and inflammation in IBD. Further longitudinal studies evaluating the individual dynamics of TRP and KYN pathway in patients with IBD, as well as the nature of precise mechanisms regulating KYNA synthesis, should be helpful in better understanding the processes underlying the observed changes.