The clinical significance of human S100A8/A9 (h-S100A8/A9) in patients with inflammatory bowel disease (IBD) is poorly understood.To clarify whether serum S100A8/A9 is a sensitive biomarker for IBD.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.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.Serum h-S100A8/A9 is superior to CRP as a sensitive biomarker for IBD.
Arginase is an enzyme that catalyses the hydrolysis of arginine to urea and ornithine. It is abundantly present in the liver of ureotelic animals (i.e. those whose excretion is characterized by the excretion of uric acid as the chief end-product of nitrogen metabolism), but its purification has hitherto not been simple, and the yield not high. Starting with a partially truncated cDNA for human liver arginase recently made available, we constructed an expression plasmid that had tandemly linked tac promotors placed upstream of a full-length cDNA. By selecting Escherichia coli strain KY1436 as the host micro-organism, we established an efficient system for the production of human liver arginase protein. Chromatographies on CM-Sephadex G-150, DEAE-cellulose and Sephadex G-150, followed by preparative agar-gel electrophoresis, yielded 10 mg of apparently homogeneous enzyme protein from 1 g (wet wt.) of E. coli cells. E. coli-expressed human liver arginase had chemical, immunological and most catalytic properties indistinguishable from those of purified human erythrocyte arginase. However, E. coli-expressed arginase was a monomer of Mr 35,000, whereas the purified erythrocyte arginase was trimer of Mr 105,000. They differed also in pH- and temperature-stabilities. Gel-filtration experiments with these two purified arginases under various conditions, as well as with unfractionated human liver and erythrocyte cytosol preparations, indicated that the native form of human arginase should be of Mr 35,000, and that the trimeric appearance of human erythrocyte arginase after purification was an artifact of the purification procedures. It was thus concluded that, in Nature, the liver and erythrocyte arginases are identical proteins.
The S100A8/A9 complex is expressed in a subset of activated neutrophils and macrophages in acute inflammatory lesions associated with various diseases.
Objective:
To investigate (a) whether serum S100A8/A9 levels are increased in patients with unstable angina (UA); and (b) whether S100A8/A9 expression is upregulated in coronary atherosclerotic plaques of patients with UA.
Design:
Serum S100A8/A9 levels in 39 patients with stable angina (SA) and 53 patients with UA were measured. In addition, the presence of the S100A8/A9 complex in directional coronary atherectomy specimens was studied immunohistochemically. Cell types which stain positive for S100A8/A9 were identified by immunodouble staining with neutrophils and macrophages.
Results:
Mean (SD) serum S100A8/A9 levels were significantly higher in patients with UA than in those with SA (3.25 (3.08) μg/ml vs 0.77 (0.31) μg/ml, p<0.05). In patients with UA, immunodouble staining clearly showed that the S100A8/A9 complex was expressed in infiltrated neutrophils and occasional macrophages. The S100A8/A9-positive area was significantly higher in UA than in SA (mean (SD) 18.3 (14.2)% vs 1.3 (2.4)%, respectively, p<0.001).
Conclusions:
The S100A8/A9 complex may be involved in the inflammatory process of coronary atherosclerotic plaques in patients with UA.
We recently developed a hybrid protein, tentatively named human MIKO-1 (hMIKO-1), based on the amino acid sequences of human S100A8 (hS100A8) and hS100A9. Human THP-1 macrophages (THP-1m), differentiated from THP-1 cells by phorbol 12-myristate 13-acetate, were used to investigate the immune function of hMIKO-1 as a drug for inflammatory diseases. Western blotting was conducted to confirm whether hMIKO-1 binds with β-actin and nuclear factor-kappa B to form complexes in THP-1m. A polymerase chain reaction (PCR) and quantitative PCR were performed to examine changes in the messenger RNA levels of proinflammatory cytokines in THP-1m. Fluorescent immunochemical staining was used to observe the intracellular localization of hMIKO-1 and hS100A8 or hS100A9 in THP-1m. As observed microscopically, the intracellular localization of hMIKO-1 in THP-1m was consistent with that of hS100A8, suggesting the close involvement of hS100A8 in the intracellular behavior of hMIKO-1 in THP-1m. Western blotting revealed that hMIKO-1 formed complexes with intracellular proteins, such as β-actin and nuclear factor-kappa B, to negatively regulate inflammatory signal transduction in THP-1m. Flow cytometry showed that the binding of hMIKO-1 to THP-1m significantly decreased when THP-1m were preliminarily treated with a sialidase (neuraminidases) cocktail. Therefore, the present results strongly suggest that the binding of hMIKO-1 to THP-1m closely involves the sugar chains of the surface proteins of cells. The messenger RNA expression of each proinflammatory cytokine was significantly suppressed in THP-1m preliminarily treated with hMIKO-1 despite a subsequent stimulation with lipopolysaccharide. In conclusion, hMIKO-1 is a functional molecule that significantly inhibits inflammatory signal transduction in THP-1m.
We investigated a patient with type 1 diabetes mellitus undergoing pancreatic islets transplantation. In this patient, we evaluated the clinical usefulness of serial measurement of serum S100A8/A9 complex levels for detecting acute inflammatory responses associated with rejection of transplanted pancreatic islets. The serum S100A8/A9 complex was a more sensitive marker for acute inflammation associated with islet transplant rejection than the serum C-reactive protein. Thus, the serial measurement of the serum S100A8/A9 complex concentration is useful for monitoring the patients with pancreatic islet transplantation.
