The Role of Angiogenesis Factors in the Formation of Vascular Changes in Scleroderma by Assessment of the Concentrations of VEGF and sVEGFR2 in Blood Serum and Tear FluidRead the full article
Mediators of Inflammation publishes papers on all types of inflammatory mediators, including cytokines, histamine, bradykinin, prostaglandins, leukotrienes, PAF, biological response modifiers and the family of cell adhesion-promoting molecules
Chief Editor, Professor Agrawal, is an Assistant Clinical Professor of the Division of Basic and Clinical Immunology. Dr. Agrawal's research focuses on the dendritic cells of the immune system in the context of aging and autoimmunity.
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miR-10a in Peripheral Blood Mononuclear Cells Is a Biomarker for Sepsis and Has Anti-Inflammatory Function
Background. Recent literature has reported the use of circulating microRNAs (miRNAs) as biomarkers for sepsis. Immune cells play an essential role in the pathophysiology of sepsis. The aim of this prospective study was to identify miRNAs in peripheral blood mononuclear cells (PBMC) that could differentiate between sepsis and infection based on Sepsis-3 definition. Methods. A total of 62 patients (41 with sepsis and 21 with infection suffering from pneumonia but without sepsis) and 20 healthy controls were enrolled into the study. PBMC at admission were examined for a panel of 4 miRNAs (miR-10a, miR-17, miR-27a, and miR-125b), which have been documented to participate in inflammatory response in immune cells, via qRT-PCR. Data were validated in a mouse model of sepsis induced via cecal ligation and puncture (CLP) and THP-1 monocytes. Results. miR-10a levels in PBMC at admission were significantly lower in sepsis patients compared with patients with infection and healthy controls. miR-10a levels were negatively correlated with disease severity scores as well as levels for c-reactive protein and procalcitonin. In addition, low miR-10a expression had a diagnostic value for sepsis and a prognostic value for 28-day mortality in receiving operating characteristic analysis. Compared with infection patients and healthy controls, PBMC from sepsis patients also had higher levels of mitogen-activated kinase kinase kinase 7 (MAP3K7), a known target protein of miR-10a and an activator of the NF-κB pathway. In the mouse model of CLP-induced sepsis, miR-10a levels in PBMC were significantly decreased as early as 8 h after CLP. Overexpression of miR-10a in THP-1 cells significantly reduced the expression of MAP3K7 and proinflammatory cytokines including IL-6, TNF-α, and MCP-1. Conclusions. PBMC miR-10a levels are decreased in sepsis and negatively correlated with the disease severity. Levels of miR-10a could distinguish between sepsis and infection and predict 28-day mortality. miR-10a plays an anti-inflammatory role in the pathogenesis of sepsis.
MEG3 Alleviated LPS-Induced Intestinal Injury in Sepsis by Modulating miR-129-5p and Surfactant Protein D
Sepsis and intestinal injury triggered by sepsis are common in intensive care units, which can contribute to a high mortality. lncRNAs can modulate gene expression, and they are closely involved in multiple diseases, including sepsis. In our present study, we investigated the biological function of MEG3 in sepsis, especially during the intestinal injury. Currently, we observed that in LPS-induced sepsis mouse models, the intestinal injury was triggered. Meanwhile, we reported that MEG3 was greatly decreased in vivo, with an increase of miR-129-5p and inhibition of SP-D. Then, MEG3 was overexpressed, and we found that its overexpression repressed the intestinal injury via downregulating miR-129-5p in sepsis mice. Moreover, TNF-α and IL-6 expression was elevated in intestinal tissues compared to the control groups. MEG3 restrained the activation of TNF-α and IL-6, in sepsis models. Subsequently, to induce the inflammatory injury of sepsis, human colorectal Caco2 cells were treated with 10 ng/ml LPS. 10 ng/ml LPS significantly inhibited Caco2 cell proliferation and increased the apoptosis. Additionally, MEG3 was decreased whereas miR-129-5p was obviously increased in Caco2 cells incubated with LPS. Interestingly, we showed that MEG3 repressed cell apoptosis partly and enhanced Caco2 cell proliferation. miR-129-5p overexpression could reverse the effect of MEG3 in vitro. Previously, we proved SP-D was reduced in sepsis and it depressed the intestinal injury in vivo. Finally, the correlation among MEG3, miR-129-5p, and SP-D was predicted and confirmed in our investigation. These findings indicated that MEG3 might be a potential target for intestinal damage caused by sepsis via regulating miR-129-5p and SP-D.
Salvianolic Acid D Alleviates Cerebral Ischemia-Reperfusion Injury by Suppressing the Cytoplasmic Translocation and Release of HMGB1-Triggered NF-κB Activation to Inhibit Inflammatory Response
Inflammatory response participates in the overall pathophysiological process of stroke. It is a promising strategy to develop antistroke drugs targeting inflammation. This study is aimed at investigating the therapeutic effect and anti-inflammatory mechanism of salvianolic acid D (SalD) against cerebral ischemia/reperfusion (I/R) injury. A rat middle cerebral artery occlusion/reperfusion (MCAO/R) injury model was established, and an oxygen-glucose deprivation/reoxygenation (OGD/R) injury model was established in PC12 cells. Neurological deficit score, cerebral infarction, and edema were studied in vivo. Cell viability was achieved using the MTT method in vitro. The Bax, Bcl-2, cytochrome c, HMGB1, TLR4, TRAF6, NF-κB p65, p-NF-κB p65, and cleaved caspase-3 and -9 were tested via the Western blot method. Cytokines and cytokine mRNA, including TNF-α, IL-1β, and IL-6, were studied via ELISA and PCR methods. The translocation of HMGB1 and NF-κB were studied by immunofluorescence assay. The HMGB1/NeuN, HMGB1/GFAP, and HMGB1/Iba1 double staining was carried out to observe the localization of HMGB1 in different cells. Results showed that SalD alleviated neurological impairment, decreased cerebral infarction, and reduced edema in I/R rats. SalD improved OGD/R-downregulated PC12 cell viability. SalD also promoted Bcl-2 expression and suppressed Bax, cytochrome c, and cleaved caspase-3 and -9 expression. SalD decreased the intensity of TLR4, MyD88, and TRAF6 proteins both in vivo and in vitro, and significantly inhibited the NF-κB nuclear translocation induced by I/R and OGD/R. What’s more, SalD inhibited HMGB1 cytoplasmic translocation in neurons, astrocytes, and microglia in both the cortex and hippocampus regions of I/R rats. In conclusion, SalD can alleviate I/R-induced cerebral injury in rats and increase the PC12 cell viability affected by OGD/R. The anti-inflammatory mechanism of SalD might result from the decreased nuclear-to-cytoplasmic translocation of HMGB1 and the inhibition on its downstream TLR4/MyD88/NF-κB signaling.
Resistin Is Increased in Periodontal Cells and Tissues: In Vitro and In Vivo Studies
Resistin, a proinflammatory adipokine, is elevated in many inflammatory diseases. However, little is known about its performance in periodontitis. The present study is aimed at evaluating resistin expression and synthesis in periodontal cells and tissues under inflammatory/microbial stress in addition to its effects on the periodontium. In vivo, 24 male rats were randomly divided into two groups: control and ligature-induced periodontal disease. After 6 and 12 days, animals were sacrificed to analyze gene expression of adipokines, bone loss, inflammation, and resistin synthesis. In vitro, human periodontal ligament (PDL) fibroblasts were used to evaluate the expression of resistin after inflammatory stimuli. In addition, PDL fibroblasts were exposed to resistin to evaluate its role on soft and hard tissue metabolism markers. The periodontitis group demonstrated significant bone loss, an increase in the number of inflammatory cells and vascular structures, an increase in resistin expression and synthesis, and a decrease in the expression of adiponectin, leptin, and its functional receptor. PDL fibroblasts showed a significant increase in resistin expression and synthesis in response to the inflammatory stimulus by IL-1β. Resistin induced an increase in cytokine expression and a decrease in the regulation of some hard tissue and matrix formation genes in PDL fibroblasts. These data indicate that resistin is produced by periodontal cells and tissues, and this effect is enhanced by inflammatory stimuli. Moreover, resistin seems to interfere with soft and hard tissue metabolism during periodontitis by reducing markers related to matrix formation and bone tissue.
Comparison of Inhibitor and Substrate Selectivity between Rodent and Human Vascular Adhesion Protein-1
Vascular adhesion protein-1 (VAP-1) is an ectoenzyme that functions as a copper-containing amine oxidase and is involved in leukocyte adhesion at sites of inflammation. Inhibition of VAP-1 oxidative deamination has become an attractive target for anti-inflammatory therapy with demonstrated efficacy in rodent models of inflammation. A previous comparison of purified recombinant VAP-1 from mouse, rat, monkey, and human gene sequences predicted that rodent VAP-1 would have higher affinity for smaller hydrophilic substrates/inhibitors because of its narrower and more hydrophilic active site channel. An optimized in vitro oxidative deamination fluorescence assay with benzylamine (BA) was used to compare inhibition of five known inhibitors in recombinant mouse, rat, and human VAP-1. Human VAP-1 was more sensitive compared to rat or mouse VAP-1 (lowest IC50 concentration) to semicarbazide but was least sensitive to hydralazine and LJP-1207. Hydralazine had a lower IC50 in rats compared to humans, although not significant. However, the IC50 of hydralazine was significantly higher in the rat compared to mouse VAP-1. The larger hydrophobic compounds from Astellas (compound 35c) and Boehringer Ingelheim (PXS-4728A) were hypothesized to have higher binding affinity for human VAP-1 compared to rodent VAP-1 since the channel in human VAP-1 is larger and more hydrophobic than that in rodent VAP-1. Although the sensitivity of these two inhibitors was the lowest in the mouse enzyme, we found no significant differences between mouse, rat, and human VAP-1. Michaelis-Menten kinetics of the small primary amines phenylethylamine and tyramine were also compared to the common marker substrate BA demonstrating that BA had the highest affinity among the substrates. Rat VAP-1 had the highest affinity for all three substrates and mouse VAP-1 had intermediate affinity for BA and phenylethylamine, but tyramine was not a substrate for mouse VAP-1 under these assay conditions. These results suggest that comparing oxidative deamination in mouse and rat VAP-1 may be important if using these species for preclinical efficacy models.
Gene Expression Profiling of Mediators Associated with the Inflammatory Pathways in the Intestinal Tissue from Patients with Ulcerative Colitis
Background. Multiple genes have been associated with IBD, and many of these can be linked to alterations in autophagy, UPR, ubiquitination, and metabolic and immune response pathways. The aim of this study was to analyze a transcriptomic panel of mediators associated with the inflammatory pathways in the colonic mucosa of UC patients. Patients and Methods. We studied a total of 100 patients with definitive diagnosis of UC (50 active and 50 in remission) and a control group (50 subjects) without endoscopic evidence of intestinal inflammation. Colonic mucosal biopsies were taken by colonoscopy and preserved in RNA later. Gene expression were measured by real-time polymerase chain reaction (RT-PCR). Results. The gene expressions of XBP1, AGR2, HSPA5, UBE2L3, TNFRSF14, LAMP3, FCGR2A, LSP1, CTLA4, SOD2, TDO2, and ALDOB mRNA levels were significantly higher in the colonic mucosa from UC patients (both quiescent and active) as compared to the control group (). Conversely, IRGM, ORDML3, UBD, CUL2, CYLD, FOXC2, FOXO4, DOK3, and SNX20 mRNA levels were found to be significantly lower in patients with active disease, as compared to those with active disease (). Gene expressions of IRGM, CTLA4, FOXO4, SLC26A3, SLC39A4, SOD2, TDO2, and ALDOB were associated with clinical outcomes, such as medical treatment in response to aminosalicylates, histological remission, clinical course, and evolution. Conclusions: The gene expressions of FOXO4, ALDOB, SOD2, TOD2, SLC26A3, and SLC39A4 were associated with the clinical course and histological activity and are of relevance since these provide the utility of new prognostic markers in IBD. Gene expression signature showed dysregulation in mediators associated with autophagy, ubiquitination, ER stress, oxidative stress, carbohydrate metabolism, solute transport, and T cell regulation in the colonic mucosa from patients with UC, suggesting that these genes could be involved in the pathogenesis of UC.