Diminished circulating concentration of interleukin-35 in Helicobacter pylori-infected patients with peptic ulcer: Its association with FOXP3 gene polymorphism, bacterial virulence factor CagA, and gender of patients

Exploring Cytokines as Potential Target in Peptic Ulcer Disease: A Systematic Update

Peptic ulcer disease (PUD) is a widespread condition that affects millions of people each year, with an incidence rate of 0.1%-1.5%, and has a significant impact on human health. A range of stimuli, such as Helicobacter pylori, non-steroidal anti-inflammatory drugs, hyperacidity, stress, alcohol, smoking, and idiopathic disease states, can produce a sore in the gastrointestinal mucosal layer. For individuals infected with H. pylori, 2%-3% remain asymptomatic throughout their life. Although PUD treatments are available, genetic variations occurring in individuals because of geographical dissimilarity and antibiotic resistance pose limitations. Specifically, inflammatory cytokine gene polymorphisms have received immense attention in recent years because they appear to affect the severity and duration of stomach inflammation, which is induced by H. pylori infection, contributing to the initiation of PUD. In such a context, in-depth knowledge of interleukins may aid in the discovery of new targets and provide precautionary approaches for the treatment of PUD. This review aims to give insights into the importance of several interleukins that cognate with PUD and contribute to ulcer progression or healing by activating or dampening the host immunity. Furthermore, the available targets with clinical evidence have been explored in this review.

The role of toll-like receptors in peptic ulcer disease

Helicobacter pylori (HP) is the primary etiologic factor that induces events in the immune system that lead to peptic ulcers. Toll-like receptors (TLRs) are an important part of the innate immune system, as they play pivotal roles in pathogen-associated molecular pattern (PAMP) recognition of HP as well host-associated damage-associated molecular patterns (DAMPs). Recent advancements such as COX-2 production, LPS recognition through TLR2, CagL, and CagY protein of HP activating TLR5, TLR9 activation via type IV secretion system (T4SS) using DNA transfer, TLR polymorphisms, their adaptor molecules, cytokines, and other factors play a significant role in PUD. Thus, some novel PUD treatments including Chuyou Yuyang granules, function by TLR4/NF-κB signaling pathway suppression and TNF-α and IL-18 inhibition also rely on TLR signaling. Similarly glycyrrhetinic acid (GA) treatment activates TLR-4 in Ana-1 cells not via TRIF, but via MYD88 expression, which is significantly upregulated to cure PUD. Therefore, understanding TLR signaling complexity and its resultant immune modulation after host-pathogen interactions is pivotal to drug and vaccine development for other diseases as well including cancer and recent pandemic COVID-19. In this review, we summarize the TLRs and HP interaction; its pathophysiology-related signaling pathways, polymorphisms, and pharmaceutical approaches toward PUD.

The Relationship Between Serum Concentration of Interleukin-35 and FoxP3 Polymorphism in Patients Undergoing Coronary Artery Bypass Graft Surgery

Objective

To investigate the association between interleukin-35 (IL-35) levels and single nucleotide polymorphisms (rs3761548, rs3761547) of the FoxP3 gene in coronary artery bypass grafting (CABG) patients.

Methods

We conducted a prospective study including 140 patients, who were scheduled for elective isolated on-pump CABG with cardiopulmonary bypass (CPB) from January 2017 to September 2018 in the Jorjani heart center. Blood samples were collected before and 12 hours after the operation. Serum levels of IL-35 were measured by enzyme-linked immunosorbent assay and the pattern of genetic variations was assessed using single specific primer-polymerase chain reaction.

Results

The serum concentrations of IL-35 after surgery were significantly higher than pre-surgery levels (18.4±8.3 vs. 9.89±3.2, respectively, P=0.002). There was no significant association between genotype frequencies of rs3761548 and rs3761547 and elevated IL-35 levels (P>0.05). There were significant associations between IL-35 levels and preoperative variables, including age (r=-0.34, P=0.047) and body mass index (r=-0.41, P=0.045), and intraoperative variables, including CPB time (r=0.4, P=0.02) and mean arterial pressure (r=-0.38, P=0.046), in carriers of the rs3761548 AA genotype.

Conclusion

Serum IL-35 concentrations were significantly increased in CPB patients, which may contribute to the post-CPB compensatory anti-inflammatory response syndrome. IL-35 increased levels were not influenced by FoxP3 promoter polymorphisms (rs3761548, rs3761547).

The important role played by chemokines influence the clinical outcome of Helicobacter pylori infection

The extended infection with Helicobacter pylori (H. pylori), one of the most frequent infectious agents in humans, may cause gastritis, peptic ulcers, gastric mucosa-associated lymphoid tissue (MALT) lymphoma, and gastric cancer. During H. pylori infection, different kinds of inflammatory cells such as dendritic cells, macrophages, neutrophils, mast cells, eosinophils, T cells and B cells are accumulated into the stomach. The interactions between chemokines and their respective receptors recruit particular types of the leukocytes that ultimately determine the nature of immune response and therefore, have a main influence on the consequence of infection. The suitable production of chemokines especially in the early stages of H. pylori infection shapes appropriate immune responses that contribute to the H. pylori elimination. The unbalanced expression of the chemokines can contribute in the induction of inappropriate responses that result in the tissue damage or malignancy. Thus, chemokines and their receptors may be promising potential targets for designing the therapeutic strategies against various types H. pylori-related gastrointestinal disorders. In this review, a comprehensive explanation regarding the roles played by chemokines in H. pylori-mediated peptic ulcer, gastritis and gastric malignancies was provided while presenting the potential utilization of these chemoattractants as therapeutic elements.

Melatonin mediated Foxp3-downregulation decreases cytokines production via the TLR2 and TLR4 pathways in H. pylori infected mice

Melatonin has important immuno-regulatory effects in inflammatory disorders but its specific role in Helicobacter pylori induced gastritis remains unclear. The aim of our study was to analyze the activity of melatonin against H. pylori induced gastritis in vivo, and explore the underlying mechanisms. The H. pylori infected mice showed extensive inflammatory cell infiltration in the gastric mucosa and submucosa, along with significantly reduced spleen and thymus weight. However, 2 and 6 weeks of treatment with 25 and 50 mg/kg melatonin restored the thymus weights relative to that of the untreated mice. TLR2 was upregulated in the gastric mucosa of the infected mice, which was restored to normal levels after 2 and 6 weeks of melatonin treatment. In contrast, TLR4 levels were similar between the treated and untreated mice. Furthermore, melatonin treatment restored spleen Foxp3 and serum TGF-β1 levels that were respectively increased and decreased in the infected mice. H. pylori infected mice also showed a decrease in the serum levels of IL-2, IL-6, IL-10, IL-17, IFN-γ and TFN-α following 2 and 6 weeks of melatonin treatment compared to the untreated mice. Melatonin treatment also resulted in decreased CD4+CD25+Foxp3+ Treg cell count in the spleen. The expression of TLR2, MyD88, p-ERK, p-p38, p65, p50 and Foxp3 in the gastric tissues were lower in the untreated mice compared to mice treated with melatonin for 2 weeks. However, the expression levels evened out after 6 weeks of treatment. Taken together, melatonin alleviates H. pylori induced gastritis by regulating TGF-β1 and Foxp3 expression via the TLR2 and TLR4 pathways.