Serum and mucosal S100 proteins, calprotectin (S100A8/S100A9) and S100A12, are elevated at diagnosis in children with inflammatory bowel disease

MiR-146a alleviates inflammatory bowel disease in mice through systematic regulation of multiple genetic networks

Introduction

Inflammatory bowel disease (IBD) is a chronic disease involving multiple genes, and the current available targeted drugs for IBD only deliver moderate efficacy. Whether there is a single gene that systematically regulates IBD is not yet known. MiR-146a plays a pivotal role in repression of innate immunity, but its function in the intestinal inflammation is sort of controversy, and the genetic regulatory networks regulated by miR-146a in IBD has not been revealed.

Methods

RT-qPCR was employed to detect the expression of miR-146a in IBD patients and in a mouse IBD model induced by dextran sulfate sodium (DSS), and then we generated a miR-146a knock-out mouse line with C57/Bl6N background. The disease activity index was scored in DSS-treated miR-146a deficiency mice and their wild type (WT) littermates. Bulk RNA-sequencing, RT-qPCR and immunostaining were done to illustrate the downstream genetic regulatory networks of miR-146a in flamed colon. Finally, the modified miR-146a mimics were used to treat DSS-induced IBD in miR-146a knock-out and WT IBD mice.

Results

We showed that the expression of miR-146a in the colon was elevated in dextran sulfate sodium (DSS)-induced IBD mice and patients with IBD. DSS induced dramatic body weight loss and more significant rectal bleeding, shorter colon length, and colitis in miR-146a knock-out mice than WT mice. The miR-146a mimics alleviated DSS-induced symptoms in both miR-146a-/- and WT mice. Further RNA sequencing illustrated that the deficiency of miR-146a de-repressed majority of DSS-induced IBD-related genes that cover multiple genetic regulatory networks in IBD, and supplementation with miR-146a mimics inhibited the expression of many IBD-related genes. Quantitative RT-PCR or immunostaining confirmed that Ccl3, Saa3, Csf3, Lcn2, Serpine1, Serpine2, MMP3, MMP8, MMP10, IL1A, IL1B, IL6, CXCL2, CXCL3, S100A8, S100A9, TRAF6, P65, p-P65, and IRAK1 were regulated by miR-146a in DSS induced IBD. Among them, MMP3, MMP10, IL6, IL1B, S100A8, S100A9, SERPINE1, CSF3, and IL1A were involved in the active stage of IBD in humans.

Discussion

Our date demonstrated that miR-146a acts as a top regulator in C57/BL6N mice to systematically repress multiple genetic regulatory networks involved in immune response of intestine to environment factors, and combinatory treatment with miR-146a-5p and miR-146a-3p mimics attenuates DSS-induced IBD in mice through down-regulating multiple genetic regulatory networks which were increased in colon tissue from IBD patients. Our findings suggests that miR-146a is a top inhibitor of IBD, and that miR-146a-5p and miR-146a-3p mimics might be potential drug for IBD.

Serum Calprotectin in the Evaluation of Gastrointestinal Diseases: An Ace up Your Sleeve?

Background: Calprotectin (CP) is a calcium- and zinc-binding protein that plays a key role in innate immunity and in the recruitment of inflammatory cells. CP can be detected both in serum and in fecal samples. Serum CP (sCP) is more specific for autoimmune diseases, while fecal CP (fCP) has been well investigated for gastrointestinal diseases. Few studies have shown the clinical effectiveness of sCP as an acute-phase biomarker for gastrointestinal diseases. Aim: The aim of this narrative review is to discuss the role of sCP as a useful alternative biomarker of the acute-phase activity of gastrointestinal diseases and as a possible tool for screening and monitoring these diseases. Material and Methods: We searched original articles, abstracts, reviews, case reports, and clinical trials on PubMed®, Up-to-Date®, and Medscape® in the last ten years. Conclusion: We found that sCP could represent a useful biomarker in the evaluation of the inflammatory stage in patients with immune-mediated gastrointestinal diseases, but more studies are needed to promote its routine use in clinical practice as a diagnostic and prognostic biomarker as a replacement for fCP.

S100A12 protein as a porcine health status biomarker when quantified in saliva samples

The S100A12 protein was validated as a biomarker of health status in porcine saliva samples using a semi-quantitative approach based on Western blotting in four healthy and sixteen diseased animals, and in four animals with severe respiratory disease during three days of antibiotic therapy. Afterwards, a non-competitive sandwich immunoassay was then developed, validated, and used to quantify S100A12 in clinical porcine samples, using 14 healthy and 25 diseased pigs. Finally, the S100A12 concentrations in the saliva of ten pigs with respiratory disease were monitored during antibiotic therapy. Diseased animals showed higher concentrations of S100A12 than healthy animals, and the high concentrations of S100A12 in pigs with respiratory distress were reduced after antimicrobial therapy. The assay developed showed good precision and accuracy, as well as a low limit of detection of 3.19 ng/mL. It was possible to store saliva samples at -20 °C, or even at 4 °C, for two weeks before analysis without losing the validity of the results. The concentrations of S100A12 observed in serum and saliva samples showed a moderately positive association with a correlation coefficient of 0.48. The concentrations of the new validated biomarker S100A12 are highly associated with the novel salivary biomarker of inflammation, adenosine deaminase, and moderately to highly associated with the total oxidant status. The results reported in this study provide a new way of evaluating inflammatory diseases in pigs using saliva samples, which should be further explored for disease prevention and monitoring in the field.

Serum/Faecal S100A12, CRP and lactoferrin can be used to distinguish ınfectious and non-ınfectious canine diarrhoea

OBJECTIVES

This study aimed to evaluate the diagnostic efficacies of selected inflammatory and intestinal biomarkers in cases of infectious and non-infectious diarrhoea in dogs.

METHODS

A total of 60 dogs, 12 healthy (Control Group) and 48 with diarrhoea were used. Viral, Bacterial, Parasitic (infectious) and Nutritional diarrhoea (non-infectious) subgroups (n: 12) were formed according to the aetiology, on the basis of clinical and laboratory examinations. Selected inflammatory and intestinal biomarkers (Calgranulin, S100A12; Lactoferrin, LCTF; C-reactive protein, CRP) were measured both in serum and faecal samples.

RESULTS

Compared to the Control and Nutritional Diarrhoea groups, the infectious diarrhoea groups had higher serum S100A12, LCTF, CRP, blood urea nitrogen, creatinine (CR), alanine transaminase and alkaline phosphatase, and lower glucose (GLU), sodium (Na) and potassium (K) concentrations (p < 0.05); Viral and Parasitic Diarrhoea groups had lower serum albumin (ALB) and total protein (TP) concentrations (p < 0.05). Faecal S100A12, LCTF and CRP concentrations were higher in infectious diarrhoea groups compared to the Control and Nutritional Diarrhoea groups (p < 0.05). Faecal LCTF and CRP concentrations were higher in the Bacterial Diarrhoea group than in the Viral and Parasitic Diarrhoea groups (p < 0.05).

CLINICAL SIGNIFICANCE

It was determined that serum (area under curve, AUC: 0.842 and 0.956) and faecal (AUC: 0.975 and 0.786) S100A12 and CRP concentrations in viral diarrhoea; serum (AUC: 0.956) and faecal (AUC: 0.992) LCTF concentrations in bacterial diarrhoea have diagnostic values in the diagnosis of the presence of intestinal inflammation and damage and can be used in the differential diagnosis of infectious and non-infectious diarrhoea.

Determination of the relationships between serum amyloid A, serum calprotectin and fecal calprotectin in healthy and infectious diarrheic calves and their diagnostic significances as inflammatory markers

In this study, serum amyloid A (SAA), serum calprotectin (SCalp) and fecal calprotectin (FCalp) levels were investigated in neonatal calves with infectious diarrhea. Total of 70 calves were divided into E. coli, C. parvum, C. parvum + viral, viral and control groups. Clinical parameters were recorded on days 0 and 7, post treatment. On these days, blood and stool samples were also taken. SAA, SCalp and FCalp levels were measured with commercial ELISA kits. Mean SAA levels on day 0 were measured as 0.54 (0.16-2.18) ng/ml and 38.40 (8.28-83.96) ng/ml for the diarrhea and healthy group, respectively (P < 0.001). Statistically significant difference was also obtained between the diarrhea [68.02 ng/ml 46.66-101.67] and control [24.05 ng/ml 11.92-56] groups in terms of SCalp levels on day 0 (P < 0.001). Cut-off value of SCalp to distinguish E. coli originated diarrhea from viral diarrhea was found to be 70.969 ng/ml (Sens: 94%). FCalp levels on day 0 were 93.08 (22.17-122.88) ng/ml and 87.01 ± 3.33 ng/ml in the diarrhea and healthy groups, respectively (P = 0.04). Cut-off concentration of FCalp was found to be 91.804 ng/ml (P = 0.0057). In addition, as a result of the logistic regression analysis, FCalp's ability to identify animals with diarrhea was found to be 6.316 times (P = 0.009) higher. The highest levels of SCalp and FCalp measured on day 0 were found among E. coli group. As a result, the importance of FCalp and SCalp in diagnosing the status of infectious diarrhea in calves for the first time in the veterinary literature is emphasized.

Changes in S100A8/A9 and S100A12 and Their Comparison with Other Analytes in the Saliva of Pigs with Diarrhea Due to E. coli

The family of calgranulins includes S100A8 (calgranulin A), S100A9 (calgranulin B), which can appear as a heterodimer known as S100A8/A9 or calprotectin, and S100A12 (calgranulin C). These proteins are related to different inflammatory conditions, immune-mediated diseases, and sepsis and are considered biomarkers of potential interest. This study aims to evaluate if S100A8/A9 and A12 could change in pigs with diarrhea due to E. coli and to compare the changes of S100A8/A9 and A12 with other analytes in order to explore the possible causes or mechanisms involved. For this purpose, a panel integrated by analytes related to inflammation (haptoglobin, inter-alpha trypsin inhibitor 4 (ITIH4), and total protein); immune system (adenosine deaminase, ADA); stress (alpha-amylase); tissue damage (lactate and lactate dehydrogenase (LDH)); sepsis (aldolase) and redox status (ferric-reducing ability of saliva (FRAS) and advanced oxidation protein products (AOPP)) was evaluated. S100A8/A9 and A12 and the other analytes measured in this study showed increases in the saliva of pigs with diarrhea due to E. coli. S100A8/A9 and/or A12 showed a significant correlation of different magnitude with some of the other analytes evaluated. Further studies should be conducted to gain knowledge about the possible practical applications as biomarkers of the measurements of S100A8/A9 and A12 in the saliva of pigs.

S-100 Proteins: Basics and Applications as Biomarkers in Animals with Special Focus on Calgranulins (S100A8, A9, and A12)

S100 proteins are a group of calcium-binding proteins which received this name because of their solubility in a 100% saturated solution of ammonium sulphate. They have a similar molecular mass of 10-12 KDa and share 25-65% similarity in their amino acid sequence. They are expressed in many tissues, and to date 25 different types of S100 proteins have been identified. This review aims to provide updated information about S100 proteins and their use as biomarkers in veterinary science, with special emphasis on the family of calgranulins that includes S100A8 (calgranulin A; myeloid-related protein 8, MRP8), S100A9 (calgranulin B; MRP14), and S100A12 (calgranulin C). The proteins SA100A8 and S100A9 can be linked, forming a heterodimer which is known as calprotectin. Calgranulins are related to the activation of inflammation and the immune system and increase in gastrointestinal diseases, inflammation and sepsis, immunomediated diseases, and obesity and endocrine disorders in different animal species. This review reflects the current knowledge about calgranulins in veterinary science, which should increase in the future to clarify their role in different diseases and potential as biomarkers and therapeutic targets, as well as the practical use of their measurement in non-invasive samples such as saliva or feces.

The use of calgranulin-C (S100A12) and fecal zonulin as possible non-invasive markers in children with inflammatory bowel disease: a clinical study

Calgranulin-C (S100A12) and zonulin are considered markers of intestinal inflammation. Our aim was to evaluate fecal S100A12 (f-S100A12) and fecal zonulin (f-zonulin) in children with inflammatory bowel disease (IBD), compared to fecal calprotectin (FC) and serum inflammatory markers. We enrolled children with a previous diagnosis of Crohn's disease (CD) and ulcerative colitis (UC). F-S100A12, f-zonulin, and FC were determined by enzyme-linked immunosorbent assay (ELISA). Endoscopic examination was considered in the patients who underwent ileocolonoscopy within 2 weeks from the enrollment. One hundred seventeen children, 39.3% with CD and 60.7% with UC were enrolled. In both CD and UC, there was a significant direct correlation between FC and f-S100A12 levels. In children with CD and UC, both FC and f-S100A12 correlated with markers of serum inflammation. We found difference in FC and f-S100A12 levels between patients in clinical relapse and remission (FC: mean 1027 ± 818 mcg/ml vs 580 ± 695 mcg/ml respectively, p = 0.028; f-S100A12: mean 66.4 ± 48.2 mcg/ml vs 42.7 ± 40 mcg/ml, respectively p = 0.02). Moreover, we found difference in FC between children with endoscopic inflammation and remission (mean 825 ± 779 mcg/ml vs 473.3 ± 492 mcg/ml, respectively p = 0.048), as well as for f-S100A12 (53 ± 43 mcg/ml vs mean 31 ± 33 mcg/ml vs, respectively p = 0.019). No significant results were found for f-zonulin.

CONCLUSION

Our data suggest that f-S100A12 and FC are both useful non-invasive biomarkers in the management of pediatric IBD in follow up and in monitoring endoscopic and clinical relapse.

WHAT IS KNOWN

• Fecal calprotectin (FC), fecal S100A12 (f- S100A12), and fecal zonulin represent potential noninvasive markers of gut inflammation. • Since S100A12 is predominantly expressed by granulocytes, high levels of f-S100A12 should be more specific for inflammation than FC.

WHAT IS NEW

• FC and f-S100A12 were correlated to each other and despite the lack of correlation with disease location, they were associated with endoscopic inflammation and clinical relapse in children with IBD. • No significant correlations were found between f-zonulin and the inflammatory parameters.

Advanced Glycation End-Products and Their Effects on Gut Health

Dietary advanced glycation end-products (AGEs) are a heterogeneous group of compounds formed when reducing sugars are heated with proteins, amino acids, or lipids at high temperatures for a prolonged period. The presence and accumulation of AGEs in numerous cell types and tissues are known to be prevalent in the pathology of many diseases. Modern diets, which contain a high proportion of processed foods and therefore a high level of AGE, cause deleterious effects leading to a multitude of unregulated intracellular and extracellular signalling and inflammatory pathways. Currently, many studies focus on investigating the chemical and structural aspects of AGEs and how they affect the metabolism and the cardiovascular and renal systems. Studies have also shown that AGEs affect the digestive system. However, there is no complete picture of the implication of AGEs in this area. The gastrointestinal tract is not only the first and principal site for the digestion and absorption of dietary AGEs but also one of the most susceptible organs to AGEs, which may exert many local and systemic effects. In this review, we summarise the current evidence of the association between a high-AGE diet and poor health outcomes, with a special focus on the relationship between dietary AGEs and alterations in the gastrointestinal structure, modifications in enteric neurons, and microbiota reshaping.

Identification and validation of the common pathogenesis and hub biomarkers in Hirschsprung disease complicated with Crohn’s disease

Background

Although increasing evidence has supported that Hirschsprung disease (HSCR) is the risk factor for children developing Crohn’s disease (CD), the common mechanism of its co-occurrence remains unknown. The purpose of this study is to further explore the underlying mechanism and biomarkers for the co-occurrence of HSCR and CD.

Methods

The Gene Expression Omnibus (GEO) database was used to obtain gene expression profiles for CD (GSE95095) and HSCR (GSE98502). Following the identification of the shared differentially expressed genes (DEGs) of CD and HSCR, functional annotation, protein–protein interaction (PPI) network creation, and module assembly were performed to discover hub genes. RT-qPCR was performed to validate the expression of the hub genes in HSCR samples. The receiver operating characteristic (ROC) curve was utilized to assess the accuracy of the hub genes as biomarkers in predicting CD in both the training dataset and test dataset.

Results

A total of 103 common DEGs (50 downregulated genes and 53 upregulated genes) were chosen for further investigation. The importance of chemokines and cytokines in these two disorders is highlighted by functional analysis. MCODE plug identified three important modules, which functionally enriched the immune system process. Finally, nine hub genes were identified using cytoHubba, including IL1B, IL10, CXCL10, ICAM1, EGR1, FCGR3A, S100A12, S100A9, and FPR1. The nine hub genes were mainly enriched in immune- and inflammation-related pathways. External data profiles and RT-qPCR confirmed the expression of the nine hub genes in HSCR and CD. ROC analysis revealed that the nine hub genes had a strong diagnostic value.

Conclusion

Our study reveals the common pathogenesis of HSCR and CD. These hub genes and diagnostic models may provide novel insight for the diagnosis and treatment of HSCR complicated with CD.

Intestinal S100/Calgranulin Expression in Cats with Chronic Inflammatory Enteropathy and Intestinal Lymphoma

Simple Summary

Intestinal diseases in cats are complicated diseases in which intestinal inflammation is difficult to distinguish from lymphoma, which is a neoplasm. In this study, the expression of the proteins S100A8/A9 and S100A12 (also called calgranulins) in the intestine is investigated in both diseases and for potential correlations with microscopically visible changes in the intestine or the clinical severity of the disease. Only small differences were seen between healthy and diseased animals, and there were no differences between cats with intestinal inflammation and lymphoma. However, several correlations of cells staining positive for calgranulins and inflammatory changes at the microscopic level and clinical disease severity were shown. This indicates that calgranulins play a role in both gastrointestinal lymphoma and inflammation and would support the recent theory that these two diseases might not be separate disease entities but instead are related. Further insights into the role of the calgranulins in these feline diseases will lead to a better understanding of the disease pathogenesis and, thus, potentially novel diagnostics and treatment avenues.

Abstract

Diagnosing chronic inflammatory enteropathies (CIE) in cats and differentiation from intestinal lymphoma (IL) using currently available diagnostics is challenging. Intestinally expressed S100/calgranulins, measured in fecal samples, appear to be useful non-invasive biomarkers for canine CIE but have not been evaluated in cats. We hypothesized S100/calgranulins to play a role in the pathogenesis of feline chronic enteropathies (FCE) and to correlate with clinical and/or histologic disease severity. This retrospective case-control study included patient data and gastrointestinal (GI) tissues from 16 cats with CIE, 8 cats with IL, and 16 controls with no clinical signs of GI disease. GI tissue biopsies were immunohistochemically stained using polyclonal α-S100A8/A9 and α-S100A12 antibodies. S100A8/A9⁺ and S100A12⁺ cells were detected in all GI segments, with few significant differences between CIE, IL, and controls and no difference between diseased groups. Segmental inflammatory lesions were moderately to strongly correlated with increased S100/calgranulin-positive cell counts. Clinical disease severity correlated with S100A12⁺ cell counts in cats with IL (ρ = 0.69, p = 0.042) and more severe diarrhea with colonic lamina propria S100A12⁺ cells with CIE (ρ = 0.78, p = 0.021) and duodenal S100A8/A9⁺ cells with IL (ρ = 0.71, p = 0.032). These findings suggest a role of the S100/calgranulins in the pathogenesis of the spectrum of FCE, including CIE and IL.

Morbid Obesity in Women Is Associated with an Altered Intestinal Expression of Genes Related to Cancer Risk and Immune, Defensive, and Antimicrobial Response

Background: Little is known about the relation between morbid obesity and duodenal transcriptomic changes. We aimed to identify intestinal genes that may be associated with the development of obesity regardless of the degree of insulin resistance (IR) of patients. Material and Methods: Duodenal samples were assessed by microarray in three groups of women: non-obese women and women with morbid obesity with low and high IR. Results: We identified differentially expressed genes (DEGs) associated with morbid obesity, regardless of IR degree, related to digestion and lipid metabolism, defense response and inflammatory processes, maintenance of the gastrointestinal epithelium, wound healing and homeostasis, and the development of gastrointestinal cancer. However, other DEGs depended on the IR degree. We mainly found an upregulation of genes involved in the response to external organisms, hypoxia, and wound healing functions in women with morbid obesity and low IR. Conclusions: Regardless of the degree of IR, morbid obesity is associated with an altered expression of genes related to intestinal defenses, antimicrobial and immune responses, and gastrointestinal cancer. Our data also suggest a deficient duodenal immune and antimicrobial response in women with high IR.

Intramucosal Calprotectin Expression in Inflammatory Bowel Disease (IBD) and Non-IBD Colorectal Inflammation

BACKGROUND: Inflammatory bowel disease (IBD) diagnosis remains a challenge accompanied with high numbers of misdiagnosis causing suboptimal management. Tons of trials have been conducted to improve the diagnostic accuracy, one of which is the use of biomarker such as calprotectin. Calprotectin can be detected in tissue (intramucosal) and is becoming a potential marker of IBD. AIM: This study aims to determine intramucosal calprotectin expression in IBD, non-IBD colitis, and control. METHODS: This analytic retrospective study included consecutively sampled IBD and non-IBD colitis colorectal biopsy specimens, and control group obtained from Cipto Mangunkusumo Hospital registered from 2017 to 2019. Cases were included in the study if specimens were indicative of IBD and non-IBD clinically and histopathologically and no abnormality were found histopathologically in the control group. Specimens with non-adequate data from the hospital medical records or with missing tissue slides were excluded from the study. Calprotectin immunostaining was conducted to evaluate mean intramucosal calprotectin expression (cell/HPF) in each group. RESULTS: Most of the samples from IBD and non-IBD group (45 samples each) showed mild active inflammation. Mucosal calprotectin expression in aforementioned groups was higher than that of control group (p < 0.001). Subjects with active inflammation showed higher calprotectin expression compared to those with inactive inflammation (p < 0.001). Calprotectin expression was also related to activity grade. CONCLUSION: Higher calprotectin expression showed significant association with the presence of inflammation and disease activity. However, the application of intramucosal calprotectin immunohistochemistry test to determine inflammatory etiology (IBD vs. non-IBD) still needs to be further evaluated.

Gut Microbiota Is a Potential Biomarker in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn's disease (CD), is characterized by relapse and remission alternately. It remains a great challenge to diagnose and assess disease activity during IBD due to the lack of specific markers. While traditional biomarkers from plasma and stool, such as C-reactive protein (CRP), fecal calprotectin (FC), and S100A12, can be used to measure inflammation, they are not specific to IBD and difficult to determine an effective cut-off value. There is consensus that gut microbiota is crucial for intestinal dysbiosis is closely associated with IBD etiopathology and pathogenesis. Multiple studies have documented differences in the composition of gut microbiota between patients with IBD and healthy individuals, particularly regarding microbial diversity and relative abundance of specific bacteria. Patients with IBD have higher levels of Proteobacteria and lower amounts of Bacteroides, Eubacterium, and Faecalibacterium than healthy individuals. This review summarizes the pros and cons of using traditional and microbiota biomarkers to assess disease severity and treatment outcomes and addresses the possibility of using microbiota-focused interventions during IBD treatment. Understanding the role of microbial biomarkers in the assessment of disease activity and treatment outcomes has the potential to change clinical practice and lead to the development of more personalized therapies.

DSS-induced inflammation in the colon drives a proinflammatory signature in the brain that is ameliorated by prophylactic treatment with the S100A9 inhibitor paquinimod

Background

Inflammatory bowel disease (IBD) is established to drive pathological sequelae in organ systems outside the intestine, including the central nervous system (CNS). Many patients exhibit cognitive deficits, particularly during disease flare. The connection between colonic inflammation and neuroinflammation remains unclear and characterization of the neuroinflammatory phenotype in the brain during colitis is ill-defined.

Methods

Transgenic mice expressing a bioluminescent reporter of active caspase-1 were treated with 2% dextran sodium sulfate (DSS) for 7 days to induce acute colitis, and colonic, systemic and neuroinflammation were assessed. In some experiments, mice were prophylactically treated with paquinimod (ABR-215757) to inhibit S100A9 inflammatory signaling. As a positive control for peripheral-induced neuroinflammation, mice were injected with lipopolysaccharide (LPS). Colonic, systemic and brain inflammatory cytokines and chemokines were measured by cytokine bead array (CBA) and Proteome profiler mouse cytokine array. Bioluminescence was quantified in the brain and caspase activation was confirmed by immunoblot. Immune cell infiltration into the CNS was measured by flow cytometry, while light sheet microscopy was used to monitor changes in resident microglia localization in intact brains during DSS or LPS-induced neuroinflammation. RNA sequencing was performed to identify transcriptomic changes occurring in the CNS of DSS-treated mice. Expression of inflammatory biomarkers were quantified in the brain and serum by qRT-PCR, ELISA and WB.

Results

DSS-treated mice exhibited clinical hallmarks of colitis, including weight loss, colonic shortening and inflammation in the colon. We also detected a significant increase in inflammatory cytokines in the serum and brain, as well as caspase and microglia activation in the brain of mice with ongoing colitis. RNA sequencing of brains isolated from DSS-treated mice revealed differential expression of genes involved in the regulation of inflammatory responses. This inflammatory phenotype was similar to the signature detected in LPS-treated mice, albeit less robust and transient, as inflammatory gene expression returned to baseline following cessation of DSS. Pharmacological inhibition of S100A9, one of the transcripts identified by RNA sequencing, attenuated colitis severity and systemic and neuroinflammation.

Conclusions

Our findings suggest that local inflammation in the colon drives systemic inflammation and neuroinflammation, and this can be ameliorated by inhibition of the S100 alarmin, S100A9.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-021-02317-6.

Calprotectin: from biomarker to biological function

The incidence of inflammatory bowel diseases (IBD) emerged with Westernisation of dietary habits worldwide. Crohn's disease and ulcerative colitis are chronic debilitating conditions that afflict individuals with substantial morbidity and challenge healthcare systems across the globe. Since identification and characterisation of calprotectin (CP) in the 1980s, faecal CP emerged as significantly validated, non-invasive biomarker that allows evaluation of gut inflammation. Faecal CP discriminates between inflammatory and non-inflammatory diseases of the gut and portraits the disease course of human IBD. Recent studies revealed insights into biological functions of the CP subunits S100A8 and S100A9 during orchestration of an inflammatory response at mucosal surfaces across organ systems. In this review, we summarise longitudinal evidence for the evolution of CP from biomarker to rheostat of mucosal inflammation and suggest an algorithm for the interpretation of faecal CP in daily clinical practice. We propose that mechanistic insights into the biological function of CP in the gut and beyond may facilitate interpretation of current assays and guide patient-tailored medical therapy in IBD, a concept warranting controlled clinical trials.

Immunological Traits of Patients with Coexistent Inflammatory Bowel Disease and Periodontal Disease: A Systematic Review

This systematic review assessed studies that evaluated the immunological traits of patients with both inflammatory bowel disease (IBD) and periodontal disease. An electronic search for literature was conducted on PubMed, Embase, Scopus, Cochrane and Web of Science. Studies that evaluated the immunological response in patients with IBD and periodontal disease were considered eligible for inclusion. A total of 6 cross-sectional studies of 275 patients were included. Immunological analyses were performed in gingival crevicular fluid, saliva, serum, intestinal and gingival biopsies. Four studies identified that the presence of IBD and periodontal disease was associated with higher levels of prostaglandin E2, aMMP8, IL-18 and S100A12, respectively, when compared to patients without the coexistence of both diseases. Furthermore, another study identified higher aMMP-8 levels with increasing severity of periodontitis in Crohn’s disease patients. The quality of overall evidence ranged from high to low due to the observational nature of contributing studies. The coexistence of IBD and periodontal disease seems to be associated with a more responsive inflammatory reaction compared with individuals having one or the other. More randomized controlled studies evaluating the coexistence of IBD and periodontitis are required to better explore the immunological interplay between them.

In Vitro Inhibitory Effect of Recombinant Human Calprotectin on Nalm6 Leukemia Cell Line

BACKGROUND & PURPOSE

In evaluating new drugs for the treatment of various types of cancer, investigations have been made to discover a variety of anti-tumor compounds with less side effects on normal cells. Investigations have shown that the heterodimers S100A8 and S100A9 inhibit the enzyme casein kinase 2 and then prevent the activation of the E7 oncoprotein. Therefore, the aim of this study was to evaluate the effect of calprotectin as an antitumor compound on the Nalm6 (B cell precursor leukemia cell line).

MATERIALS & METHODS

Transformation of genes encoding S100A8 and S100A9 human, designed in the pQE32 plasmid, was performed by the thermal shock method into E. coli M15 bacteria. After bacterial growth in LB medium, the expression of two S100A8 and S100A9 subunits, the solubility of the protein by SDS-PAGE method was determined. Finally, the S100A8 / A9 complex was equally placed in the microtube. In the next step, the cytotoxic effects of calprotectin produced on the Nalm6 cell line were evaluated using the wst1 test. Then, the apoptosis in these cells was measured using flow cytometry methods with Annexin-V coloration.

RESULTS

In the current study, the results showed that the cytotoxic effects of Calprotectin are time and concentration- dependent. Therefore, it can reduce the tumor expression and had a beneficial effect by induced apoptosis in Nalm6 cell line.

CONCLUSION

Calprotectin has an anti-tumor effect on the Nalm6 cell line by increasing apoptosis.

Differential expression and role of S100 proteins in chronic rhinosinusitis

PURPOSE OF REVIEW

Immune system modulators have been under investigation to help elucidate the underlying pathophysiologies of chronic rhinosinusitis (CRS). Psoriasin (S100A7) and calgranulins (S100A8, S100A9, and S100A12) are S100 proteins that have been studied for their immune-mediating responses to pathogens within the context of CRS. This review highlights the expression patterns and proposed roles of S100 proteins in CRS with (CRSwNP) and without (CRSsNP) nasal polyps.

RECENT FINDINGS

Elevated levels of S100A7 and S100A12 were measured in the sinonasal tissues of patients with CRSsNP compared with CRSwNP and controls. S100A12 expression in CRSsNP was significantly correlated to disease severity. Contrastingly, increased S100A8, S100A9, and S100A8/A9 levels were demonstrated in the nasal polyp tissues of patients with CRSwNP compared with those in inferior turbinate and uncinate tissues of patients with CRSsNP and controls.

SUMMARY

The reported differential expression patterns and activities of psoriasin and calgranulins suggest that S100 proteins exert unique and concerted roles in mediating immunity in different subtypes of CRS. These studies will enable further investigations focused on understanding the immune-modulating mechanisms of S100 proteins in different inflammatory signaling pathways and disease phenotypes of CRS toward the pursuit of identifying new biomarkers and targets for improved outcomes.

The Close Interplay of Nitro-Oxidative Stress, Advanced Glycation end Products and Inflammation in Inflammatory Bowel Diseases

BACKGROUND

Inflammatory Bowel Disease (IBD) exhibits no defined aetiology. However, factors such as genetic and nitro-oxidative stress are associated with chronic inflammation and IBD progression to Colorectal Cancer (CRC). The present review discusses the association of nitro-oxidative stress, inflammation and Advanced Glycation End products (AGE) and their corresponding receptor (RAGE) in IBD and examines the connection between these factors and nuclear factors, such as Nuclear Factor Kappa B (NF-κB), factorerythroid 2-related factor-2 (Nrf2), and p53 Mutant (p53M).

METHODS

We searched the PubMed, ScienceDirect and Web of Science databases using a combination of the following terms: IBD, CRC, oxidative stress, inflammation, NF-κB, Nrf2, p53M, AGE and RAGE.

RESULTS

Oxidative stress and inflammation activated two cellular pathways, the nuclear expression of pro-inflammatory, pro-oxidant and pro-oncogenic genes based on NF-κB and p53M, which is associated with NF-κB activation, Deoxyribonucleic acid (DNA) damage and the expression of pro-oncogenic genes. Nrf2 stimulates the nuclear expression of enzymatic and non-enzymatic antioxidant systems and anti-inflammatory genes, and is inhibited by chronic oxidative stress, NF-κB and p53M. AGE/RAGE are involved in inflammation progression because RAGE polymorphisms and increased RAGE levels are found in IBD patients. Alterations of these pathways in combination with oxidative damage are responsible for IBD symptoms and the progression to CRC.

CONCLUSION

IBD is an inflammatory and nitro-oxidative stress-based bowel disease. Achieving a molecular understanding of the biochemical events and their complicated interactions will impact basic and applied research, animal models, and clinical trials.

Value of S100A12 in predicting in-stent restenosis in patients with coronary drug-eluting stent implantation

In-stent restenosis (ISR) after drug-eluting stent (DES) placement has recently emerged as a major concern for cardiologists. Identification of biomarkers to predict ISR may be invaluable for tailored management strategies. The present study aimed to evaluate the prognostic utility of circulating S100 calcium-binding protein A12 (S100A12) for ISR. Out of 2,443 patients with DES-based percutaneous coronary intervention (PCI) and follow-up angiography at ~1 year after DES-based PCI, 258 patients were diagnosed with ISR and 258 patients without ISR were randomly selected as controls. Serum S100A12 levels were determined in the two subsets on admission. The association between ISR and the circulating levels of S100A12 was determined by constructing two multivariate stepwise logistic regression models. In addition, S100A12 was assessed for its ability to predict ISR using receiver operating characteristic (ROC) curve analysis. The serum levels of S100A12 at baseline were significantly elevated in patients in the ISR group compared with those in the non-ISR group (P<0.001). In the multivariate logistic regression analysis, after adjusting for conventional cardiovascular risk factors, laboratory parameters and medication after the procedure, the S100A12 level was revealed to be independently associated with ISR. When a cut-off for serum S100A12 levels of 34.75 ng/ml was used, the ROC curve was able to predict ISR with 72.8% sensitivity and 79.1% specificity, and the area under the ROC curve was 0.796 (95% CI: 0.757 to 0.834, P<0.001). Furthermore, addition of S100A12 to established risk factors significantly improved the predictive power of reference models for ISR. S100A12 may serve as an independent marker to predict ISR in patients undergoing coronary DES implantation.

Serum S100A8/A9 as a Potentially Sensitive Biomarker for Inflammatory Bowel Disease

BACKGROUND

The clinical significance of human S100A8/A9 (h-S100A8/A9) in patients with inflammatory bowel disease (IBD) is poorly understood.

OBJECTIVE

To clarify whether serum S100A8/A9 is a sensitive biomarker for IBD.

METHODS

Serum specimens from outpatients with IBD (n = 101) and healthy volunteers (HVs) (n = 101) were used in this study. Enzyme-linked immunosorbent assays for h-S100A8/A9 and inflammatory cytokines were performed using these specimens. Further, correlation analysis was performed to investigate the significance of h-S100A8/A9 fluctuation in patients with IBD.

RESULTS

The average of serum h-S100A8/A9 concentration in outpatients with IBD was significantly higher than that in HVs. The concentration of h-S100A8/A9 in patients with IBD was barely correlated with that of CRP and inflammatory cytokines. Despite that finding, the serum level of h-S100A8/A9 in patients with ulcerative colitis (UC) was correlated with the severity of IBD, compared with other inflammatory proteins.

CONCLUSION

Serum h-S100A8/A9 is superior to CRP as a sensitive biomarker for IBD.

S100 family proteins in inflammation and beyond

The S100 family proteins possess a variety of intracellular and extracellular functions. They interact with multiple receptors and signal transducers to regulate pathways that govern inflammation, cell differentiation, proliferation, energy metabolism, apoptosis, calcium homeostasis, cell cytoskeleton and microbial resistance. S100 proteins are also emerging as novel diagnostic markers for identifying and monitoring various diseases. Strategies aimed at targeting S100-mediated signaling pathways hold a great potential in developing novel therapeutics for multiple diseases. In this chapter, we aim to summarize the current knowledge about the role of S100 family proteins in health and disease with a major focus on their role in inflammatory conditions.

Plasma calprotectin is superior to serum calprotectin as a biomarker of intestinal inflammation in ulcerative Colitis

Background and aims: Despite promising results, only a few studies have been published on serum calprotectin as a biomarker in IBD. Recently, plasma measurements of calprotectin have been shown to be more reliable than serum measurements. In this study, we aim to assess plasma and serum calprotectin measurements as biomarkers of disease activity in paediatric and adult ulcerative colitis.Methods: Paediatric (5-18 years) and adult (>18 years) patients scheduled for colonoscopy due to suspected or confirmed ulcerative colitis were included prospectively. Stool and blood samples were collected at time of colonoscopy and patient symptom scores were recorded. At colonoscopy the Ulcerative Colitis Endoscopic Index of Severity was recorded. Histology was graded according to the Geboes score.Results: 84 patients where included; 30 paediatric and 54 adult patients. Plasma calprotectin had a stronger correlation to all outcome variables than serum calprotectin. Plasma calprotectin correlated positively to disease extent (Rho = 0.53, p < .0001), symptoms scores (Rho = 0.54, p = .002, only in the paediatric cohort), endoscopic scores (Rho = 0.39, p = .0003), histological scores (Rho 0.28, p = .01) and, when using endoscopic assessment of severity as reference, could discriminate active disease from patients in remission (p = .03).Conclusions: While more studies are needed to assess if plasma calprotectin can discriminate healthy individuals from ulcerative colitis, this study indicates that plasma calprotectin can be used as a biomarker of disease activity, especially in cases where faecal calprotectin measurements are cumbersome either due to patient compliance or logistical requirements.

Exosome-Induced Regulation in Inflammatory Bowel Disease

An exosome (30-150 nm size) is a cell-derived vesicle. Exosome-induced regulation in inflammatory bowel disease (IBD) is becoming increasingly popular due to their potential functions of exosomal pathways. Exosomes, which are involved in the regulation of IBD, can be released from various cell types, or found in many physiological fluids, and plants. The specific functions of exosomes in IBD primarily depend on the internal functional components, including RNAs, proteins, and other substances. However, exosome-induced transport mechanisms involving cell-cell communications or cell-environment interactions are also very important. Recent studies have revealed that exosome crosstalk mechanisms may influence major IBD-related pathways, such as immune responses, barrier functions, and intestinal flora. This review highlights the advancements in the biology of exosome secretions and their regulation in IBD. The functional roles of exosomal components, including nucleic acids, proteins, and some other components, are the main focus of this review. More animal and clinical research is needed to study the functions of exosomes on IBD. Designing new drug dosage form using exosome-like-structure may provide new insights into IBD treatment. This review suggests a potential significance for exosomes in IBD diagnosis and treatment.

Ca2+-Binding Proteins of the EF-Hand Superfamily: Diagnostic and Prognostic Biomarkers and Novel Therapeutic Targets

A multitude of Ca²⁺-sensor proteins containing the specific Ca²⁺-binding motif (helix-loop-helix, called EF-hand) are of major clinical relevance in a many human diseases. Measurements of troponin, the first intracellular Ca-sensor protein to be discovered, is nowadays the "gold standard" in the diagnosis of patients with acute coronary syndrome (ACS). Mutations have been identified in calmodulin and linked to inherited ventricular tachycardia and in patients affected by severe cardiac arrhythmias. Parvalbumin, when introduced into the diseased heart by gene therapy to increase contraction and relaxation speed, is considered to be a novel therapeutic strategy to combat heart failure. S100 proteins, the largest subgroup with the EF-hand protein family, are closely associated with cardiovascular diseases, various types of cancer, inflammation, and autoimmune pathologies. The intention of this review is to summarize the clinical importance of this protein family and their use as biomarkers and potential drug targets, which could help to improve the diagnosis of human diseases and identification of more selective therapeutic interventions.

Mucosal expression of S100A12 (calgranulin C) and S100A8/A9 (calprotectin) and correlation with serum and fecal concentrations in dogs with chronic inflammatory enteropathy

S100A12 and S100A8/A9 (calprotectin) are released from activated mononuclear cells and belong to the group of damage associated molecular patterns. Fecal S100A12 and S100A8/A9 concentrations have been suggested as biomarkers of intestinal inflammation in dogs with chronic inflammatory enteropathies (CIE). However, the mucosal cellular infiltrate in dogs with CIE is primarily lymphocytic-plasmacytic. Whether fecal S100A12 and S100A8/A9 levels reflect the number and/or activity of intestinal mucosal mononuclear cells, or whether these proteins are also produced by other cells has not been investigated. Thus, the aim of this study was to evaluate intestinal mucosal S100A12 and S100A8/A9 positivity and a potential relationship with the respective protein concentrations in serum and fecal samples in dogs with CIE. Serum (single sample), fecal samples (from 3 consecutive days), and gastrointestinal tissue biopsies (i.e., stomach, duodenum, ileum, and colon) were evaluated from 21 dogs with CIE. Serum and fecal S100A12 and S100A8/A9 concentrations were measured by analytically validated in-house ELISAs. Tissue biopsies underwent routine histopathology and immunohistochemical evaluation for S100A12 and S100A8/A9 positivity (S100A12⁺ and S100A8/A9⁺, each recorded as positive cells/mm²). S100A12⁺ and S100A8/A9⁺ cells were identified in all segments of the gastrointestinal tract, but were predominantly localized in the lamina propria (LP). Duodenal LP S100A12 positivity correlated statistically significantly with that in the stomach and ileum (ρ = 0.66 and 0.69, both p < 0.01), but was inversely correlated with the severity of macrophage infiltration in the duodenum (ρ=-0.47, p = 0.042). Ileal LP S100A8/A9 positivity correlated positively with the extent of ileal neutrophil and macrophage infiltration (ρ=0.61, p = 0.047). Fecal S100A12 concentrations strongly correlated with the number of S100A12⁺ cells along the entire gastrointestinal tract (ρ = 0.76, p = 0.028), whereas serum S100A12 concentrations were inversely correlated to colonic S100A12⁺ cell counts (ρ=-0.50, p = 0.043). Mucosal S100A8/A9⁺ cell counts were not associated with the corresponding fecal or serum S100A8/A9 concentrations. These results suggest that the intestinal mucosa in dogs with CIE contains an increased number of activated (pro-inflammatory) phagocytes expressing and secreting the S100A12 protein, but the macrophage population seen on routine histopathology is predominantly mature (anti-inflammatory) with a reduced or absent expression of S100A12 and a normal or increased expression of S100A8/A9. However, the distribution of intestinal S100A8/A9 expression requires further study.

Serum Calprotectin in Adolescents With Inflammatory Bowel Disease-A Pilot Investigation

OBJECTIVES

Fecal calprotectin (FC) is a well-integrated parameter in the monitoring of adolescent patients with inflammatory bowel disease (IBD). However, measurement of FC is limited by day-to-day-variation and by the feces consistency. Furthermore, adolescents are often noncompliant to deliver fecal sampling leading to suboptimal monitoring. Consequently, we see the need of a substitute biomarker whenever measurement of FC fails and aimed to investigate serum calprotectin (SC) in adolescents with IBD.

METHODS

In cross sectional data from 19 ulcerative colitis (UC) patients <18 years old, a Spearman correlation was used to analyze the correlation between SC, FC, C-reactive protein (CRP) and endoscopic and symptom scores. In longitudinal data collected from 20 UC and Crohn disease (CD) patients (10-17 years old), Mixed Effect Models (MEM) were used to analyze the association between SC, FC, CRP, and symptom scores.

RESULTS

We found positive correlations between SC (19 samples) and the endoscopic score, symptom score, and CRP (r = 0.56, P = 0.01; r = 0.64, P = 0.003; r = 0.97, P < 0.0001). We found no significant correlation between SC and FC. In 27 samples from UC patients, the association of SC with FC and CRP were positive and significant (P = 0.004, estimate = 0.32; P = 0.0001, estimate = 0.002). The association between SC and symptom score was insignificant. In 49 samples from CD patients, the association between SC and CRP was significant (P = 0.02, estimate = 0.002) whereas associations between SC and FC and symptom score were insignificant.

CONCLUSIONS

In the current pilot study, we found a correlation between SC and the endoscopically assessed inflammation in UC. SC may have the potential to improve disease monitoring of adolescent patients.

Observational study on Swedish plaque psoriasis patients receiving narrowband-UVB treatment show decreased S100A8/A9 protein and gene expression levels in lesional psoriasis skin but no effect on S100A8/A9 protein levels in serum

S100A8 and S100A9 proteins are highly upregulated in patients with psoriasis and have been proposed as potential biomarkers for psoriasis. The present study was designed to analyze the effect of narrowband ultraviolet B therapy on these proteins.

S100A8, S100A9 gene expression and S100A8/A9 heterocomplex protein levels were analyzed in lesional and non-lesional skin before and after narrowband-UVB treatment in patients with chronic plaque type psoriasis. In addition, disease severity was measured by psoriasis area and severity index (PASI) and serum protein levels of S100A8/A9 were repeatedly analyzed. Narrowband-UVB treatment significantly reduced S100A8, S100A9 gene expression and S100A8/A9 protein levels in lesional skin while serum levels showed no significant change. No correlation between PASI and serum S100A8/A9 protein levels was found. These results implicate a role of S100A8/A9 in the anti-inflammatory effect of narrowband-UVB. Serum S100A8/A9 levels do not respond to treatment suggesting that serum S100A8/A9 does not originate from psoriasis skin keratinocytes. Serum S100A8/A9 levels do not correlate with PASI questioning serum S100A8/A9 as a biomarker for psoriasis skin activity.

Trial Registration: DRKS 00014817.

Zinc source influences the gene expression of zinc transporters in jejunum and cecal tonsils during broiler challenge with Eimeria maxima and Clostridium perfringens

The objective of this experiment was to study the effects of dietary zinc (Zn) source on gene expression of Zn transporters (metallothionein [MT], ZIP 3, 5, 8, 9, 10, 11, 13, and 14, and ZnT 1, 4, 5, 6, 7, 9, and 10) in the jejunum and cecal tonsils of broilers challenged with coccidia or coccidia plus Clostridium perfringens. A 2 × 2 factorial design was used with 2 Zn sources (90 mg Zn/kg from either ZnSO4 or an organic Zn, Bioplex® Zn) and challenged with approximately 5,000 oocysts of Eimeria maxima at 14 d of age with or without C. perfringens (108 CFU/bird) at 18, 19, and 20 d of age (8 pens per treatment and 8 birds per pen) after which 1 bird/pen was sampled at 21 d of age. In the jejunum, co-infection resulted in higher ZnT 5 and 6 gene expression, while organic Zn fed birds had lower ZIP 5 and 11, and higher ZnT1. Additionally, an interaction of challenge by Zn source was noted wherein ZnT10 was unaffected by the C. perfringens in the organic Zn treatment but was 2.7-fold lower in the co-infected ZnSO4 fed birds. S100A9 gene expression, a biomarker of inflammatory response in necrotic enteritis, increased 2 and 2.8-fold in the cecal tonsils and jejunum with the co-infection, respectively. Supplementation with organic Zn lowered S100A9 by 1.9 and 4.4-fold in the cecal tonsils and jejunum, respectively, when birds were supplemented with ZnSO4. Notably, MT, ZIP 3, 8, 9, 10, 13, or 14, and ZnT 4, 7, and 9 were unaffected by Zn source and/or method of challenge. An interaction of challenge by Zn source was also noted for serum Zn concentration, which was reduced when birds were challenged with C. perfringens and fed ZnSO4 but no difference between challenge method when birds were fed organic Zn. Based on the expression of ZnT and ZIP genes, more Zn trafficking due to treatment occured in the jejunum than cecal tonsils, but further studies are needed to ascertain how Zn source regulates intracellular free Zn concentrations and whole-body Zn status during an enteric challenge.

The RAGE signaling pathway is involved in intestinal inflammation and represents a promising therapeutic target for Inflammatory Bowel Diseases

Inflammatory Bowel Diseases (IBD) are chronic inflammatory conditions of the intestinal tract. IBD are believed to result from an inappropriate immune response against the intestinal flora in genetically predisposed patients. The precise etiology of these diseases is not fully understood, therefore treatments rely on the dampening of symptoms, essentially inflammation, rather than on the cure of the disease. Despite the availability of biologics, such as anti-TNF antibodies, some patients remain in therapeutic failure and new treatments are thus needed. The multiligand receptor for advanced glycation end-products (RAGE) is a pattern recognition receptor implicated in inflammatory reactions and immune system activation. Here, we investigated the role of RAGE in intestinal inflammation and its potential as a therapeutic target in IBD. We showed that RAGE was upregulated in inflamed tissues from IBD patients compared to controls. Rage^-/- mice were less susceptible to intestinal and colonic inflammation development than WT mice. WT mice treated with the RAGE-specific inhibitor FPS-ZM1 experienced less severe enteritis and colitis. We demonstrated that RAGE could induce intestinal inflammation by promoting oxidative stress and endothelial activation which were diminished by FPS-ZM1 treatment. Our results revealed the RAGE signaling pathway as a promising therapeutic target for IBD patients.

Damage-associated molecular patterns in inflammatory bowel disease: From biomarkers to therapeutic targets

The chronic inflammatory process underlying inflammatory bowel disease (IBD), comprising Crohn’s disease and ulcerative colitis, derives from the interplay of several components in a genetically susceptible host. These components include environmental elements and gut microbiota a dysbiosis. For decades, immune abnormalities have been investigated as critically important in IBD pathogenesis, and attempts to develop effective therapies have predominantly targeted the immune system. Nevertheless, immune events represent only one of the constituents contributing to IBD pathogenesis within the context of the complex cellular and molecular network underlying chronic intestinal inflammation. These factors need to be appreciated within the milieu of non-immune components. Damage-associated molecular patterns (DAMPs), which are essentially endogenous stress proteins expressed or released as a result of cell or tissue damage, have been shown to act as direct pro-inflammatory mediators. Excessive or persistent signalling mediated by such molecules can underlie several chronic inflammatory disorders, including IBD. The release of endogenous DAMPs amplifies the inflammatory response driven by immune and non-immune cells and promotes epigenetic reprogramming in IBD. The effects determine pathologic changes, which may sustain chronic intestinal inflammation and also underlie specific disease phenotypes. In addition to highlighting the potential use of DAMPs such as calprotectin as biomarkers, research on DAMPs may reveal novel mechanistic associations in IBD pathogenesis and is expected to uncover putative therapeutic targets.

Expression patterns common and unique to ulcerative colitis and celiac disease

Autoimmune diseases like celiac disease (CeD) and ulcerative colitis (UC) show a common genetic background defined by the existence of shared susceptibility loci. We aimed to go deeper into this common genetic background through performing a cross-disease study based on gene expression. We measured the expression of 21 genes located in 13 CeD-UC susceptibility regions, and 10 genes in five CeD risk regions. Determinations were carried out in colon/rectum samples from 13 UC patients (inflamed and uninflamed tissue) and four colon samples from controls. Duodenal samples from 19 CeD patients and 12 controls were used for comparisons. Differences were analyzed using the Bayesian method. The shared chromosomal regions containing TNFAIP3, PTPN2, ICOSLG, C1orf106, and IL21 showed similar results in both diseases. FASLG, PLEK, CCR4, and TAGAP, all located in CeD risk loci, were up-regulated in both CeD and UC patients. Finally, ZFP36L1, ZMIZ1, PUS10, UBE2L3, and BACH2 showed opposite results in CeD and UC. A high complexity underlies autoimmune common susceptibility loci, as the expression pattern of the studied genes does not always correlate with the one expected attending to the apparent genetic background. Differentially expressed genes such as ZFP36L1, ZMIZ1, PUS10, and BACH2 deserve further research in autoimmune diseases.

Microbiota-sensitive epigenetic signature predicts inflammation in Crohn's disease

Altered response to the intestinal microbiota strongly associates with inflammatory bowel disease (IBD); however, how commensal microbial cues are integrated by the host during the pathogenesis of IBD is not understood. Epigenetics represents a potential mechanism that could enable intestinal microbes to modulate transcriptional output during the development of IBD. Here, we reveal a histone methylation signature of intestinal epithelial cells isolated from the terminal ilea of newly diagnosed pediatric IBD patients. Genes characterized by significant alterations in histone H3-lysine 4 trimethylation (H3K4me3) showed differential enrichment in pathways involving immunoregulation, cell survival and signaling, and metabolism. Interestingly, a large subset of these genes was epigenetically regulated by microbiota in mice and several microbiota-sensitive epigenetic targets demonstrated altered expression in IBD patients. Remarkably though, a substantial proportion of these genes exhibited H3K4me3 levels that correlated with the severity of intestinal inflammation in IBD, despite lacking significant differential expression. Collectively, these data uncover a previously unrecognized epigenetic profile of IBD that can be primed by commensal microbes and indicate sensitive targets in the epithelium that may underlie how microbiota predispose to subsequent intestinal inflammation and disease.

Local S100A8 Levels Correlate With Recurrence of Experimental Autoimmune Uveitis and Promote Pathogenic T Cell Activity

Purpose

To investigate the role of damage-associated molecular patterns (DAMPs) in recurrent experimental autoimmune uveitis (EAU).

Methods

Recurrent EAU was induced in Lewis rats by interphotoreceptor retinoid-binding protein (IRBP) R16-peptide specific T cells (tEAU). Aqueous humor and serum samples were kinetically collected and DAMPs examined by quantitative proteomics, Western blot analysis, and ELISA. tEAU rats were treated with S100 inhibitor paquinimod followed by disease evaluation. The functions of T effector cells and T regulatory cells (Tregs) were compared between treated and nontreated groups. The expression of costimulatory molecules on antigen-presenting cells was examined by flow cytometry.

Results

S100A8, but not high mobility group box 1 (HMGB1), in the eye was found to be correlated with intraocular inflammatory episodes. Administration of paquinimod significantly protected tEAU rats from recurrence. Treated tEAU rats had fewer R16-specific Th1 and Th17 cells, but increased numbers of Tregs. R16-specific T cells from treated tEAU rats into naïve recipients prevented induction of tEAU by R16-specific T cells from nontreated tEAU rats. Moreover, APCs from treated tEAU rats expressed higher levels of a negative costimulatory molecule, CD200R, and lower levels of CD80, CD86, and MHC class II molecules compared to APCs from nontreated tEAU rats. An opposite pattern of expression of these molecules was observed on APCs incubated in vitro with recombinant S100A8.

Conclusions

Our data demonstrate a link between local expression of DAMPs and autoimmune responses, and suggest that complete S100A8/A9 blockade may be a new therapeutic target in recurrent autoimmune uveitis.

Calgranulin C (S100A12) Is Differentially Expressed in Subtypes of Chronic Rhinosinusitis

Background Calgranulin C (S100A12) is an innate immune peptide at the air-mucosal interface associated with neutrophil involvement, which when overexpressed has been implicated as a biomarker of inflammatory diseases. Decreased epithelial expression of certain innate immune peptides has been reported in chronic rhinosinusitis (CRS). We hypothesized that S100A12 is differentially expressed in the sinonasal mucosa of patients with CRS compared to controls and that S100A12 is a potential biomarker of CRS-specific quality of life (QOL) and disease severity. Methods A prospective observational study was conducted which included 70 patients: 17 controls, 28 having CRS without (CRSsNP), and 25 with (CRSwNP) nasal polyps. The expression of S100A12 and human neutrophil elastase (HNE) was assessed in the anterior ethmoid tissues from all patients using enzyme-linked immunosorbent assay (ELISA) and immunohistochemical (IHC) analyses. Disease-specific QOL (Rhinosinusitis Disability Index) and disease severity (computed tomography [CT] and endoscopy) were evaluated and correlated to the expression levels of S100A12. Results S100A12 and HNE were significantly elevated in patients with CRSsNP compared to normal controls ( P < .05 and P < .001, respectively) and patients with CRSwNP ( P < .05 and P < .001, respectively), as measured by ELISA and IHC analyses. Patients with CRS exhibited worse CRS-specific disease severity compared to normal controls ( P < .05), and the increased protein levels of S100A12 were significantly correlated to disease severity, represented by CT scores ( P < .05). Conclusions S100A12 is differentially expressed in CRS subtypes and is significantly elevated in patients with CRSsNP and associated with CRS-specific disease severity.

HBx-induced S100A9 in NF-κB dependent manner promotes growth and metastasis of hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is associated with hepatitis B virus (HBV) infection. Myeloid-specific S100 proteins (S100s), namely, S100A8, S100A9 and S100A12, have been recently recognized as newly discovered damage-associated molecular patterns (DAMPs) that are correlated with progression in pathogen of infectious diseases. However, whether S100s are regulated by HBV and involved in HBV-related hepatocarcinogenesis are still unclear. Here, we found that all expression levels of myeloid-specific S100s (S100A8, S100A9 and S10012) were elevated in serum and tissue samples from HCC patients. Expression of S100A9 but not S100A8 and S10012 were also higher in blood serum and tissue samples from HBV-positive HCC patients than that in HBV-negative HCC patients. High levels of intracellular and extracellular S100A9 were also confirmed in HepG2 cells expressing 1.3-fold HBV genome or HBV-encoded X protein (HBx) as well as in a stable HBV-producing cell line HepG2.2.15. HBx was shown to facilitate translocation of NF-κB from the cytoplasm to the nucleus, and NF-κB bound to the promoter of S100A9 to enhance its transcription. Silencing S100A9 expression partially blocked HBx-induced growth and metastasis of HepG2 cells both in vitro and in vivo. Further, serum S100A9 levels were found to correlate with TNM stage, extrahepatic metastasis status and HBV DNA load in HBV-related HCC and also had a better diagnostic value for identifying extrahepatic metastasis. Our these data demonstrate that S100A9 plays a pivotal role in HBx-induced growth and metastasis of HCC and may serve as a potential diagnostic marker for extrahepatic metastasis.

The Host Antimicrobial Protein Calgranulin C Participates in the Control of Campylobacter jejuni Growth via Zinc Sequestration

Campylobacter jejuni is a leading cause of bacterially derived gastroenteritis worldwide. Campylobacter is most commonly acquired through the consumption of undercooked poultry meat or through drinking contaminated water. Following ingestion, Campylobacter adheres to the intestinal epithelium and mucus layer, causing toxin-mediated inflammation and inhibition of fluid reabsorption. Currently, the human response to infection is relatively unknown, and animal hosts that model these responses are rare. As such, we examined patient fecal samples for the accumulation of the neutrophil protein calgranulin C during infection with Campylobacter jejuni In response to infection, calgranulin C was significantly increased in the feces of humans. To determine whether calgranulin C accumulation occurs in an animal model, we examined disease in ferrets. Ferrets were effectively infected by C. jejuni, with peak fecal loads observed at day 3 postinfection and full resolution by day 12. Serum levels of interleukin-10 (IL-10) and tumor necrosis factor alpha (TNF-α) significantly increased in response to infection, which resulted in leukocyte trafficking to the colon. As a result, calgranulin C increased in the feces of ferrets at the time when C. jejuni loads decreased. Further, the addition of purified calgranulin C to C. jejuni cultures was found to inhibit growth in a zinc-dependent manner. These results suggest that upon infection with C. jejuni, leukocytes trafficked to the intestine release calgranulin C as a mechanism for inhibiting C. jejuni growth.

S100A12 concentrations and myeloperoxidase activities are increased in the intestinal mucosa of dogs with chronic enteropathies

Background

Intestinal mucosal S100A12 and myeloperoxidase (MPO) are inflammatory biomarkers in humans with inflammatory bowel disease (IBD). However, these biomarkers have not been studied in the intestinal mucosa of dogs with chronic enteropathies (CE), even though dogs with CE have increased S100A12 concentrations in feces and serum. This study investigated mucosal S100A12 concentrations and MPO activities in both dogs with CE and healthy Beagles. ELISA (S100A12 concentrations) and spectrophotometric methods (MPO activity) were used. The associations of both biomarkers with canine IBD activity index (CIBDAI), histopathologic findings, clinical outcome, and serum albumin concentrations were also investigated. We studied intestinal mucosal samples originating from different intestinal regions of 40 dogs with CE and 18 healthy Beagle dogs (duodenum, ileum, colon, and cecum).

Results

Compared with healthy Beagles, mucosal S100A12 concentrations in dogs with CE were significantly higher in the duodenum (p < 0.0001) and colon (p = 0.0011), but not in the ileum (p = 0.2725) and cecum (p = 0.2194). Mucosal MPO activity of dogs with CE was significantly higher in the duodenum (p < 0.0001), ileum (p = 0.0083), colon (p < 0.0001), and cecum (p = 0.0474). Mucosal S100A12 concentrations in the duodenum were significantly higher if the inflammatory infiltrate consisted mainly of neutrophils (p = 0.0439) or macrophages (p = 0.037). Mucosal S100A12 concentrations also showed a significant association with the severity of total histopathological injury and epithelial injury in the colon (p < 0.05). Mucosal MPO activity showed a significant association (p < 0.05) with the severity of total histopathological injury, epithelial injury, and eosinophil infiltration in the duodenum. There was no significant association of both biomarkers with CIBDAI or clinical outcome.

Conclusions

This study showed that both mucosal S100A12 concentrations and MPO activities are significantly increased in the duodenum and colon of dogs with CE; mucosal MPO was also increased in the ileum and cecum. Future research should focus on assessing the clinical utility of S100A12 and MPO as diagnostic markers in dogs with CE.

Association between serum S100A9 levels and liver necroinflammation in chronic hepatitis B

BACKGROUND

S100A9 protein, which is recently classified as a novel damage associated molecular pattern, is released from stressed cells undergoing necrosis or secreted by living cells undergoing a stress that act as endogenous danger signal associated with infection, tissue damage and cancer. Here, we evaluated the relationship of serum S100A9 with viral replication and liver necroinflammation in patients with chronic hepatitis B (CHB) infection.

METHODS

A total of one hundred and eighty-three recruited patients with CHB infection underwent liver biopsy for grading of necroinflammation (G) and staging of fibrosis (S). Forty-nine healthy individuals were included as healthy controls (HCs). Serum S100A9 levels were determined by enzyme-linked immunosorbent assay. Correlations of serum S100A9 with viral replication and liver necroinflammation were analyzed. The receiver operating characteristic curve was used to assess the discriminating power of serum S100A9 to grade liver necroinflammation (G). Liver normal L02 cells were transfected with a HBV plasmid, and S100A9 levels were determined.

RESULTS

Serum S100A9 levels were increased in CHB patients compared to HCs. Intrahepatic immunoreactivity for S100A9 was enhanced in liver sample from CHB patients. Infection of HBV also resulted in an elevated S100A9 expression in L02 cells. Serum S100A9 was correlated with the serum HBV DNA levels. CHB patients with moderate-to-severe liver necroinflammation (G ≥ 2) showed significantly higher serum S100A9 levels than those without or with mild necroinflammation (G < 2). In patients with normal ALT levels, the area under the curve (AUC) of S100A9 for discriminating patients with moderate-to-severe necroinflammation (G ≥ 2) was 0.791 [95% confidence interval (CI), 0.670-0.913] with 91.7% sensitivity, 65.0% specificity and 78.3% accuracy. In patients with an alanine aminotransferase (ALT) < 2 upper limit of normal, the AUC of S100A9 for discriminating patients with moderate-to-severe necroinflammation (G ≥ 2) was 0.826 (95% CI, 0.729-0.923) with 87.9% sensitivity, 72.5% specificity and 80.2% accuracy.

CONCLUSIONS

HBV infection may enhance S100A9 expression. Serum S100A9 levels are correlated with viral load. Serum S100A9 has potential to discriminate the grades of liver necroinflammation, particularly in CHB patients with normal or mildly increased ALT levels.

Identification of potential serum biomarkers of acute paraquat poisoning in humans using an iTRAQ quantitative proteomic

Paraquat (PQ) poisoning has high mortality rates in many countries. Due to it readily being absorbed through the gastrointestinal tract and rapidly excreted in the urine, few biomarkers possess satisfactory specificity and sensitivity in diagnostic and forensic practices. To investigate serum biomarkers in patients with PQ poisoning, pooled sera was analyzed using a proteomic approach based on iTRAQ coupled LC-MS/MS. Of the 413 proteins identified with high confidence, 81 were found to be differentially expressed (1.5-fold change) in the sera of patients with PQ poisoning. The differential expression pattern of 4 of these proteins was validated by enzyme-linked immunosorbent assay (ELISA) in clinical samples. A sera sample from a PQ poisoning patient has shown relatively increased abundance of S100A8 and S100A9. The overexpression of S100A8 and S100A9 was further validated in the lung tissue of PQ-treated rat associated with lung damage. Meanwhile, we identified another two down-expressed proteins, transferrin receptor protein 1 (TfR1) and serum amyloid P-component (SAP), which may be also practicable in human clinical samples as PQ poisoning serum biomarkers. Furthermore, receiver operating characteristic curve analysis confirmed that the expression levels of S100 alarmins, TfR1 and SAP in patient serum could provide a discriminatory diagnostic test for predicting PQ poisoning in patients. Therefore, our results suggest that increased serum levels of S100 alarmins and decreased serum levels of TfR1 and SAP may constitute potential biomarkers for the prediction of PQ poisoning in humans, and might be novel therapeutic targets in PQ poisoning.

Coevolution of the Toll-Like Receptor 4 Complex with Calgranulins and Lipopolysaccharide

Toll-like receptor 4 (TLR4) induces inflammation in response to both pathogen- and host-derived molecules. Lipopolysaccharide (LPS) recognition by TLR4 has been shown to occur across the amniotes, but endogenous signaling through TLR4 has not been validated outside of placental mammals. To determine whether endogenous danger signaling is also shared across amniotes, we studied the evolution of TLR4-activation by the calgranulin proteins (S100A8, S100A9, and S100A12), a clade of host molecules that potently activate TLR4 in placental mammals. We performed phylogenetic and syntenic analysis and found MRP-126—a gene in birds and reptiles—is likely orthologous to the mammalian calgranulins. We then used an ex vivo TLR4 activation assay to establish that calgranulin pro-inflammatory activity is not specific to placental mammals, but is also exhibited by representative marsupial and sauropsid species. This activity is strongly dependent on the cofactors CD14 and MD-2 for all species studied, suggesting a conserved mode of activation across the amniotes. Ortholog complementation experiments between the calgranulins, TLR4, CD14, and MD-2 revealed extensive lineage specific-coevolution and multi-way interactions between components that are necessary for the activation of NF-κB signaling by calgranulins and LPS. Our work demonstrates that calgranulin activation of TLR4 evolved at least ~320 million years ago and has been conserved in the amniote innate immune system.

S100A9 gene silencing inhibits the release of pro-inflammatory cytokines by blocking the IL-17 signalling pathway in mice with acute pancreatitis

The study aimed to investigate whether S100A9 gene silencing mediating the IL‐17 pathway affected the release of pro‐inflammatory cytokines in acute pancreatitis (AP). Kunming mice were assigned to the normal, AP, AP + negative control (NC), AP + shRNA, AP + IgG and AP + anti IL‐17 groups. ELISA was applied to measure expressions of AMY, LDH, CRP, TNF‐α, IL‐6 and IL‐8. The cells were distributed into the control, blank, NC, shRNA1 and shRNA2 groups. MTT assay, flow cytometry, RT‐qPCR and Western blotting were used to evaluate cell proliferation, cell cycle and apoptosis, and expressions of S100A9, TLR4, RAGE, IL‐17, HMGB1 and S100A12 in tissues and cells. Compared with the normal group, the AP group displayed increased expressions of AMY, LDH, CRP, TNFα, IL‐6, IL‐8, S100A9, TLR4, RAGE, IL‐17, HMGB1 and S100A12. The AP + shRNA and AP + anti IL‐17 groups exhibited an opposite trend. The in vivo results: Compare with the control group, the blank, NC, shRNA1 and shRNA2 groups demonstrated increased expressions of S100A9, TLR4, RAGE, IL‐17, HMGB1 and S100A12, as well as cell apoptosis and cells at the G1 phase, with reduced proliferation. Compared with the blank and NC groups, the shRNA1 and shRNA2 groups had declined expressions of S100A9, TLR4, RAGE, IL‐17, HMGB1 and S100A12, as well as cell apoptosis and cells at the G1 phase, with elevated proliferation. The results indicated that S100A9 gene silencing suppressed the release of pro‐inflammatory cytokines through blocking of the IL‐17 pathway in AP.

Detection of calprotectin in inflammatory bowel disease: Fecal and serum levels and immunohistochemical localization

The aim of the present study was to quantify calprotectin levels using an enzyme-linked immunosorbent assay (ELISA) and a point-of-care test (POCT) in patients with inflammatory bowel disease. Overall, 113 patients with ulcerative colitis (UC; 51 men and 62 women) and 42 patients with Crohn's disease (CD; 29 men and 13 women), who were scheduled to undergo a colonoscopy, were prospectively enrolled and scored endoscopically and clinically. An additional 96 healthy, age-matched subjects served as the normal controls. Feces and blood samples from the patients with UC and CD, and the normal controls were analyzed. These patients had received adequate medical treatment. The tissue distribution of calprotectin was investigated using immunohistochemistry. The fecal calprotectin levels, as measured using an ELISA, were correlated with the endoscopic and clinical disease activities and laboratory parameters, including serum levels of hemoglobin (Hb), albumin and C-reactive protein, and erythrocyte sedimentation rate, particularly among the patients with UC. The fecal Hb level was close to that of the fecal calprotectin level (r=0.57; P<0.0001). The fecal calprotectin level measured using an ELISA was well-correlated with the fecal calprotectin level measured using the POCT (r=0.81; P<0.0001), but was not correlated with the serum calprotectin level (r=0.1013; P=0.47). An immunohistochemical investigation revealed that patients with both UC and CD had higher neutrophil and monocyte/macrophage calprotectin-positive cell expression levels, compared with those in the normal controls. Fecal calprotectin was considered a reliable marker for disease activity, and the assessment of fecal calprotectin via POCT showed potential as a rapid and simple measurement in clinical settings.

Clinical significance of fecal calprotectin for the early diagnosis of abdominal type of Henoch-Schonlein purpura in children

The objective of this study is to explore the value of fecal calprotectin (FC) for early screening of the abdominal type of Henoch-Schonlein purpura (AHSP) in children. The study cohort included 40 children with AHSP treated at Shengjing Hospital of China Medical University from November 2014 to November 2015, and 40 children hospitalized in the Division of Pediatric Orthopedics in the corresponding period were selected as a control group. Fresh fecal samples were collected in the acute phase of the first visit (FC1), 3 days after treatment (FC2), and 7 days after treatment (FC3) from the AHSP group and the control group. Calprotectin levels in the fecal samples were measured using an enzyme-linked immunosorbent assay. At the same time, gastrointestinal performance and the laboratory examination indicators white blood cell (WBC) count and C-reactive protein (CRP) level were recorded. The median levels of FC1 (3053 μg/g) and FC2 (2778.3 μg/g) were higher than in the control group (102.5 μg/g), with significant differences among the three groups (p < 0.001). FC levels gradually decreased in remission, and the level of FC3 on day 7 was close to that of the control samples (p > 0.05). When the optimal cut-off was 264.5 μg/g, the area under the receiver operating characteristic (ROC) curve of FC for diagnosis of AHSP was 0.961 with a corresponding sensitivity and specificity of 93.1 and 87.5%, respectively. The levels of FC in children with AHSP were positively correlated with WBC count (r _s = 0.688) and CRP value (r _s = 0.513). The area under the ROC curve of WBC count for screening AHSP was 0.785 when the optimal cut-off value was 11.1 × 10⁹/L with a corresponding sensitivity and specificity of 81.5 and 62.5%, respectively. The area under the ROC curve of CRP was 0.963 when the optimal cut-off value was 5.72 mg/dL with a corresponding sensitivity and specificity of 88.9 and 100%, respectively. Comparisons of FC, WBC count, and CRP level as diagnostic indicators of AHSP showed that the sensitivity of FC was higher than that of the WBC count and CRP level, and its diagnostic value was better than that of the WBC count. The levels of FC began to increase in the early stages of AHSP, showing a decreasing tendency in remission and tending to be within a normal range after a week or so. For the early diagnosis of AHSP, FC with a cut-off level of 264.5 μg/g has good sensitivity and specificity. The sensitivity of FC is better than that of the traditional inflammation indicators CRP and WBC count, and its diagnostic performance is better than WBC count; FC can be suitable as a new marker for the early diagnosis of AHSP.