ADAM proteases involved in inflammation are differentially altered in patients with gastritis or ulcer

Glycosylated, Lipid-Binding, CDR-Like Domains of SARS-CoV-2 ORF8 Indicate Unique Sites of Immune Regulation

The outbreak of the novel coronavirus SARS-CoV-2 has posed a significant threat to human health and the global economy since the end of 2019. Unfortunately, due to the virus's rapid evolution, preventingand controlling the epidemic remains challenging. The ORF8 protein is a unique accessory protein in SARS-CoV-2 that plays a crucial role in immune regulation, but its molecular details are still largely unknown. In this study, we successfully expressed SARS-CoV-2 ORF8 in mammalian cells and determined its structure using X-ray crystallography at a resolution of 2.3 Å. Our findings reveal several novel features of ORF8. We found that four pairs of disulfide bonds and glycosylation at residue N78 are essential for stabilizing ORF8's protein structure. Additionally, we identified a lipid-binding pocket and three functional loops that tend to form CDR-like domains that may interact with immune-related proteins to regulate the host immune system. On cellular experiments also demonstrated that glycosylation at N78 regulats of ORF8's ability to bind to monocytes cells. These novel features of ORF8 provide structural insights to into its immune-related function and may serve as new targets for developing ORF8-mediated immune regulation inhibitors. IMPORTANCE COVID-19, caused by the novel coronavirus SARS-CoV-2 virus, has triggered a global outbreak. The virus's continuous mutation increases its infectivity and may be directly related to the immune escape response of viral proteins. In this study, we used X-ray crystallography to determine the structure of SARS-CoV-2 ORF8 protein, a unique accessory protein expressed in mammalian cells, at a resolution of 2.3 Å. Our novel structure reveals important structure details that shed light on ORF8's involvement in immune regulation, including conservation disulfide bonds, a glycosylation site at N78, a lipid-binding pocket, and three functional loops that tend to form CDR-like domains that may interact with immune-related proteins to modulate the host immune system. We also conducted preliminary validation experiments on immune cells. These new insights into ORF8's structure and function provide potential targets for developing inhibitors to block the ORF8-mediated immune regulation between viral protein and host, ultimately contributing to the development of novel therapeutics for COVID-19.

Expression analysis of miRNA-155 level in Helicobacter pylori related inflammation and chronic gastritis

Background and Objectives

Helicobacter pylori, is a major etiologic agent associated with gastritis. There is more evidence of noncoding microRNAs (miRs) dysregulation in gastrointestinal diseases, including inflammation caused by Helicobacter pylori. Also, the classification of gastrointestinal malignancies using the miRs profile is better than the protein profile. MiRNA-155(miRNA-155) among other miRs plays an important role in control of inflammation and gastric malignancy, so it can be remarkable prognosis marker of gastric cancer in the phase of chronic gastritis. The aim of this study was to compare the expression of miRNA-155 in gastric biopsy and serum samples of adult patients with chronic gastritis.

Materials and Methods

Biopsy and blood samples were collected from endoscopy candidates at Taleghani hospital, Tehran, during 2019. H. pylori infection was detected using histology, culture and molecular PCR methods. Based on cagA and vacA genotyping, the toxicity of H. pylori isolates were determined. After RNA extraction, the expression rate of miRNA-155 was evaluated by real-time polymerase chain reaction (RT-PCR) in gastric tissue and serum of adults infected by H. pylori (n = 30) compared with control group without infection (n = 20). RNU6 housekeeping miRNA were used as endogenous control and statistical analyses were performed using SPSS, ANOVA and Student's t-test.

Results

miRNA-155 expression in H. pylori infected adult patients increased significantly by 5.61 and 10.11 fold in serum and tissue respectively, compared to that observed in the control group. Evaluation of miRNA-155 expression pattern in relation to bacterial virulence factors showed that the increase in miRNA-155 expression is independent of CagA and VacA toxins.

Conclusion

According to the differential expression patterns of miRNA-155 in serum samples of the infected adult patients, miRNA-155 has the potential to evaluate as chronic gastritis marker.

Helicobacter pylori Infection Mediates Inflammation and Tumorigenesis-Associated Genes Through miR-155-5p: An Integrative Omics and Bioinformatics-Based Investigation

Helicobacter pylori (H. pylori) is a major human pathogenic bacterium that survives in the gastric mucosa. The aim of this study is to evaluate the expression of the target gene network of miR-155-5p in H. pylori-related gastritis using a combination of public gene expression datasets and web-based platforms. To evaluate the expression of genes related to gastritis, we used two datasets from Gene Expression Omnibus (GEO) database. Then, we determined the overlaps between the predicted miR-155-5p target genes and gastritis-dysregulated GEO datasets genes; in the next step, we identified the possible miR-155-5p target-DEGs (Target-Differentially Expressed Genes). Also, we performed multiple bioinformatics analyses to identify the most important targets and downstream pathways associated with this miRNA. Using the UCSC cancer genomic browser analysis tool, we investigated the expression of hub genes in relation to gastric cancer and H. pylori infection, as well as the potential role of hub genes in gastritis, inflammation, and cancer. In this regard, 28 differentially expressed target genes of miR-155-5p were identified. Most of the captured target genes were correlated with the host immune response and inflammation. Based on the specific patterns of expression in gastritis and cancer, CD9, MST1R, and ADAM10 were candidates for the most probable targets of miR-155-5p. Although the focus of this study is primarily on bioinformatics, we think that our findings should be experimentally validated before they can be used as potential therapeutic and diagnostic tools.

Protective effect of snail secretion filtrate against ethanol-induced gastric ulcer in mice

Gastric ulcer or peptic ulcer is a common disease worldwide. Basically, it develops when there is an imbalance between the protective and aggressive factors, especially at the luminal surface of epithelial cells. Thus, there is a constant interest in research new drugs for treatment of gastric ulcer. The snail secretion is a dense mucous, that covers the external surface of the snails, with important functions for the survival of snails. The biological proprieties of snail Helix Aspersa Muller mucus it has been known for centuries to treat human disorders in particular for skin disease. Recently the use of snail mucus has seen a worldwide increase, as a component in cosmetic product and it has been used in particular for the management of wound and skin disorders. In this study we use a murine model of ethanol intragastric administration which has been widely used to test the drugs efficacies and to explore the underlying mechanism for gastric ulcer development. The intragastric ethanol administration causes several mucosal damages and an induction of a severe inflammatory response. Our results show a significant protective effect of snail secretion filtrate in reducing macroscopic and histological lesions, as well the protective effect on mucus content, oxidative stress and inflammatory response. In conclusion this study demonstrate the protective effect of intragastrical snail secretion filtrate, in a model of ethanol-induced gastric ulcer in mice, suggesting its possible useful use in the treatment or prevention of gastric ulcer.

Gingival Crevicular Fluid Zinc- and Aspartyl-Binding Protease Profile of Individuals with Moderate/Severe Atopic Dermatitis

Atopic dermatitis (AD) is a protease-modulated chronic disorder with heterogenous clinical manifestations which may lead to an imprecise diagnosis. To date, there are no diagnostic protease tests for AD. We explored the gingival crevicular fluid (GCF) protease profile of individuals with moderate/severe AD compared to healthy controls. An exploratory case-control study was conducted. AD patients (n = 23) and controls (n = 21) were enrolled at the International Center for Clinical Studies, Santiago, Chile. Complete dermatological and periodontal evaluations (involving the collection of GCF samples) were made. The levels of 35 proteases were analyzed using a human protease antibody array in matching AD patients (n = 6) and controls (n = 6) with healthy periodontium. The GCF levels of zinc-binding ADAM8, ADAM9, MMP8, Neprilysin/CD10, aspartyl-binding Cathepsin E, serin-binding Protein convertase9, and uPA/Urokinase proteases were lower in moderate/severe AD patients compared to controls (p < 0.05). No inter-group differences in the levels of the other 28 proteases were found. MMP8, Cathepsin E, and ADAM9 were the biomarkers with the highest sensitivity and specificity regarding the detection of AD (p < 0.05). The area under receiver operating characteristic (ROC) curve for MMP8 was 0.83 and MMP8 + ADAMP9 was 0.90, with no significant differences (p = 0.132). A combined model of MMP8, Cathepsin E, and ADAM9 was not considered since it did not converge. Then, levels of MMP8 in GCF were determined using a multiplex bead immunoassay in 23 subjects with AD and 21 healthy subjects. Lower levels of MMP8 in the GCF from the AD group versus healthy group (p = 0.029) were found. This difference remained significant after adjustment by periodontitis (p = 0.042). MMP8 revealed the diagnostic potential to identify AD patients versus healthy controls, (ROC area = 0.672, p < 0.05). In conclusion, differences in the protease profile between AD and control patients were associated with MMP8, Cathepsin E, and ADAM9. Based on the multiplex assay results, MMP8 was lower in AD patients than controls, suggesting that MMP8 may be a diagnostic biomarker candidate.

Involvement of Klotho, TNF‑&alpha; and ADAMs in radiation‑induced senescence of renal epithelial cells

While radiation nephropathy is a major problem associated with radiotherapy, the exact mechanisms underlying its pathogenesis and the mediators involved in kidney deterioration remain to be elucidated. In view of the finding that senescence is typically increased post‑irradiation, the present study examined whether ionizing radiation may cause kidney injury by enhancing premature senescence. The present study explored the relevance of the aging suppressor, Klotho, which has anti‑aging activity and is highly expressed in murine renal cells/kidney tissues, under irradiation conditions. Firstly, the effects of radiation on mouse inner medullary collecting duct‑3 (mIMCD‑3) cells and kidney tissues of mice were assessed. Subsequently, the mRNA expression levels of Klotho, TNF‑α and ADAM metallopeptidase domain (ADAM)9/10/17 were analyzed by reverse transcription‑quantitative PCR following exposure to radiation. In addition, the levels of these proteins were measured by western blotting or ELISA. The results revealed that irradiation of mIMCD‑3 cells clearly triggered cellular senescence. Notably, Klotho gene expression was considerably decreased in radiation‑exposed mIMCD‑3 cells and in the kidney tissues of irradiated BALB/c mice, and the corresponding translated protein was consistently expressed following radiation exposure. Moreover, expression of TNF‑α, a negative regulator of Klotho, was significantly increased, whereas ADAM9/10/17, an ectodomain shedding enzyme of Klotho, was decreased in irradiated mIMCD‑3 cells and in the kidney tissues of BALB/c mice. Collectively, these data suggested that TNF‑α‑mediated inhibition of Klotho expression and blockage of soluble Klotho formation via decreased ADAM expression following irradiation may contribute to the development of renal dysfunction through acceleration of radiation‑induced cellular senescence.

A Functional Polymorphism-Mediated Disruption of EGR1/ADAM10 Pathway Confers the Risk of Sepsis Progression

Increasing evidence has indicated that single nucleotide polymorphisms (SNPs) are related to the susceptibility of sepsis and might provide potential evidence for the mechanisms of sepsis. Our recent preliminary study showed that the ADAM10 genetic polymorphism was clinically associated with the development of sepsis, and little is known about the underlying mechanism. The aim of this study was to confirm the association between the ADAM10 promoter rs653765 G→A polymorphism and the progression of sepsis and to discover the underlying mechanism. Clinical data showed that the rs653765 G→A polymorphism was positively correlated with the development of sepsis, as evidenced by a multiple-center case-control association study with a large sample size, and showed that EGR1 and ADAM10 levels were associated well with the different subtypes of sepsis patients. In vitro results demonstrated that the rs653765 G→A variants could functionally modulate ADAM10 promoter activity by altering the binding of the EGR1 transcription factor (TF) to the ADAM10 promoter, affecting the transcription and translation of the ADAM10 gene. Electrophoretic mobility shift assay (EMSA) followed by chromatin immunoprecipitation (ChIP) assay indicated the direct interaction. Functional studies further identified that the EGR1/ADAM10 pathway is important for the inflammatory response. EGR1 intervention in vivo decreased host proinflammatory cytokine secretion and rescued the survival and tissue injury of the mouse endotoxemia model.IMPORTANCE Sepsis is characterized as life-threatening organ dysfunction, with unacceptably high mortality. Evidence has indicated that functional SNPs within inflammatory genes are associated with susceptibility, progression, and prognosis of sepsis. These mechanisms on which these susceptible sites depended often suggest the key pathogenesis and potential targets in sepsis. In the present study, we confirmed that a functional variant acts as an important genetic factor that confers the progression of sepsis in a large sample size and in multiple centers and revealed that the variants modulate the EGR1/ADAM10 pathway and influence the severity of sepsis. We believe that we provide an important insight into this new pathway involving the regulation of inflammatory process of sepsis based on the clinical genetic evidence, which will enhance the understanding of nosogenesis of sepsis and provide the potential target for inflammation-related diseases.

Andrographolide attenuates imbalance of gastric vascular homeostasis induced by ethanol through glycolysis pathway

Different kinds of factors contribute to gastric ulcer development which characterized by damaging gastric mucosal layer. However, gastric vascular homeostasis is not well defined and whether andrographolide has a protective function is largely unknown. The goal of this study is to investigate the potential function roles and underlying mechanism by which andrographolide regulates gastric vascular homeostasis in vivo and in vitro. Gastric ulcer animal model induced on andrographolide pretreated C57/BL6 mouse by ethanol intragastric administration. Hematoxylin and Eosin Stain, Masson’s trichrome stain and Immunohistochemistry stain performed to observe gastric vascular homeostasis, which associated hemorrhage, extracellular matrix deposition and macrophage infiltration. The activity of vascular endothelial cells were associated with the proliferation and migration, which were detected using cell counting, MTS, and wound scratch healing assay. The underlying endothelial glycolytic mechanism investigated in vivo and in vitro. Andrographolide pretreatment dramatically attenuates ethanol intragastric administration induced imbalance of gastric vascular homeostasis which characterized by severe hemorrhage, increase extracellular matrix deposition and augment macrophage infiltration. Andrographolide treatment conspicuous inhibits HUVEC-C activity characterized by suppressing proliferation and migration of endothelial cells. Mechanically, andrographolide treatment significant suppresses the expression of glycolytic genes, especially decrease PFKFB3 expression. The treatment with PFKFB3 inhibitor, 3-PO, exacerbates the inhibitory function of andrographolide on vascular endothelial cell proliferation and migration. Those data Suggests that andrographolide contributes to maintain gastric vascular homeostasis, at least partially, by inhibiting PFKFB3 mediated glycolysis pathway. Andrographolide plays a crucial role in maintaining gastric vascular homeostasis during gastric ulcer development through regulating vascular endothelial cell glycolytic pathway.