muramidase and Vasculitis

Heart failure (HF) ensuing myocardial infarction (MI) is characterized by the initiation of a systemic inflammatory response. We aimed to elucidate the impact of myelomonocytic cells and their activation by angiotensin II on vascular endothelial function in a mouse model of HF after MI.. HF was induced in male C57BL/6J mice by permanent ligation of the left anterior descending coronary artery. Compared to sham, HF mice had significantly impaired endothelial function accompanied by enhanced mobilization of Sca-1+c-Kit+ haematopoietic stem cells and Sca-1-c-Kit+ common myeloid and granulocyte-macrophage progenitors in the bone marrow as well as increased vascular infiltration of CD11b+Ly6G-Ly6Chigh monocytes and accumulation of CD11b+ F4/80+ macrophages, assessed by flow cytometry. Using mice with Cre-inducible expression of diphtheria toxin receptor in myeloid cells, we selectively depleted lysozyme M+ myelomonocytic cells for 10 days starting 28 days after MI. While the cardiac phenotype remained unaltered until 38 days post-MI, myeloid cell depletion attenuated vascular accumulation of Nox2+CD45+ cells, endothelial dysfunction, oxidative stress, and vascular expression of adhesion molecules and angiotensin II receptor type 1 (AT1R). Pharmacological blockade of this receptor for 4 weeks did not significantly alter cardiac function, but mimicked the effects of myeloid cell depletion: telmisartan (20 mg/kg/day, fed to C57BL/6J mice) diminished bone marrow myelopoesis and myeloid reactive oxygen species production, attenuated endothelial leucocyte rolling and vascular accumulation of CD11b+Ly6G-Ly6Chigh monocytes and macrophages, resulting in improved vascular function with less abundance of Nox2+CD45+ cells.. Endothelial dysfunction in HF ensuing MI is mediated by inflammatory Nox2+ myeloid cells infiltrating the vessel wall that can be targeted by AT1R blockade.

Topics: Angiotensin II; Angiotensin II Type 1 Receptor Blockers; Animals; Animals, Genetically Modified; Disease Models, Animal; Endothelial Cells; Heart Failure; Leukocyte Rolling; Macrophages; Male; Mice, Inbred C57BL; Monocytes; Muramidase; Myeloid Cells; Myocardial Infarction; NADPH Oxidase 2; Oxidative Stress; Receptor, Angiotensin, Type 1; Signal Transduction; Telmisartan; Vasculitis

Lysozyme, found in relatively high concentration in blood, saliva, tears, and milk, protects us from the ever-present danger of bacterial infection. Previous studies have reported proinflammatory responses of endothelial cells to the release of polyphosphate(PolyP). In this study, we examined the anti-inflammatory responses and mechanisms of lysozyme and its effects on PolyP-induced septic activities in human umbilical vein endothelial cells (HUVECs) and mice. The survival rates, septic biomarker levels, behavior of human neutrophils, and vascular permeability were determined in PolyP-activated HUVECs and mice. Lysozyme suppressed the PolyP-mediated vascular barrier permeability, upregulation of inflammatory biomarkers, adhesion/migration of leukocytes, and activation and/or production of nuclear factor-κB, tumor necrosis factor-α, and interleukin-6. Furthermore, lysozyme demonstrated protective effects on PolyP-mediated lethal death and the levels of the related septic biomarkers. Therefore, these results indicated the therapeutic potential of lysozyme on various systemic inflammatory diseases, such as sepsis or septic shock.

Topics: Animals; Anti-Inflammatory Agents; Cells, Cultured; Dose-Response Relationship, Drug; Endothelial Cells; Humans; Male; Mice; Mice, Inbred C57BL; Muramidase; Polyphosphates; Sepsis; Treatment Outcome; Umbilical Veins; Vasculitis

Angiotensin II (ATII), a potent vasoconstrictor, causes hypertension, promotes infiltration of myelomonocytic cells into the vessel wall, and stimulates both vascular and inflammatory cell NADPH oxidases. The predominant source of reactive oxygen species, eg, vascular (endothelial, smooth muscle, adventitial) versus phagocytic NADPH oxidase, and the role of myelomonocytic cells in mediating arterial hypertension have not been defined yet.. Angiotensin II (1 mg · kg(-1) · d(-1) for 7 days) increased the number of both CD11b(+)Gr-1(low)F4/80(+) macrophages and CD11b(+)Gr-1(high)F4/80(-) neutrophils in mouse aorta (verified by flow cytometry). Selective ablation of lysozyme M-positive (LysM(+)) myelomonocytic cells by low-dose diphtheria toxin in mice with inducible expression of the diphtheria toxin receptor (LysM(iDTR) mice) reduced the number of monocytes in the circulation and limited ATII-induced infiltration of these cells into the vascular wall, whereas the number of neutrophils was not reduced. Depletion of LysM(+) cells attenuated ATII-induced blood pressure increase (measured by radiotelemetry) and vascular endothelial and smooth muscle dysfunction (assessed by aortic ring relaxation studies) and reduced vascular superoxide formation (measured by chemiluminescence, cytochrome c assay, and oxidative fluorescence microtopography) and the expression of NADPH oxidase subunits gp91(phox) and p67(phox) (assessed by Western blot and mRNA reverse-transcription polymerase chain reaction). Adoptive transfer of wild-type CD11b(+)Gr-1(+) monocytes into depleted LysM(iDTR) mice reestablished ATII-induced vascular dysfunction, oxidative stress, and arterial hypertension, whereas transfer of CD11b(+)Gr-1(+) neutrophils or monocytes from gp91(phox) or ATII receptor type 1 knockout mice did not. CONCLUSIONS- Infiltrating monocytes with a proinflammatory phenotype and macrophages rather than neutrophils appear to be essential for ATII-induced vascular dysfunction and arterial hypertension.

Topics: Angiotensin II; Animals; CD11b Antigen; Endothelium, Vascular; Gene Expression; Hypertension; Macrophages; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Monocytes; Muramidase; Muscle, Smooth, Vascular; Neutrophils; Nitric Oxide; Oxidative Stress; Reactive Oxygen Species; Receptors, Chemokine; Respiratory Burst; Vasculitis; Vasoconstrictor Agents

To characterize the antigen specificity of circulating anti-neutrophil cytoplasmic antibodies (ANCAs) in inflammatory bowel disease (IBD).. Analysis of the prevalence of circulating ANCAs in patients with ulcerative colitis and Crohn's disease, by both non-specific methods (immunofluorescence against fixed neutrophil leukocytes) and specific antigen techniques (against purified neutrophil leukocyte constituents).. Indirect immunofluorescence against fixed polymorphonuclear leukocytes, and solid-phase enzyme-linked immunosorbent assay (ELISA) against neutrophil constituents (alpha-granules, elastase, myeloperoxidase, cathepsin g, lysozyme and lactoferrin).. Although results using immunofluorescence were typical of other studies (ulcerative colitis positive in 41%, Crohn's disease in 10%), ELISA studies showed antibody activity against neutrophil components in 69% of patients with ulcerative colitis and 39% of those with Crohn's disease. Antibodies in ulcerative colitis were commonly directed (in descending order) against lysozyme, cathepsin G, elastase, and lactoferrin, and in Crohn's disease against lysozyme.. Correlation of indirect immunofluorescence data and ELISA results indicated that even this large panel of specific antigens fails to identify all the ANCA targets in IBD. The lack of correlation between the findings of ANCAs, either in general or versus a specific target, and disease extent or activity in ulcerative colitis supports the suggestion that ANCAs are unlikely to be of primary importance in pathogenesis.

Topics: Adult; Aged; Antibodies; Antibodies, Antineutrophil Cytoplasmic; Autoantibodies; Cathepsin G; Cathepsins; Cholangitis, Sclerosing; Colitis, Ulcerative; Crohn Disease; Cytoplasmic Granules; Enzyme-Linked Immunosorbent Assay; Epitopes; Female; Fluorescent Antibody Technique, Indirect; Humans; Immunoglobulin G; Inflammatory Bowel Diseases; Lactoferrin; Leukocyte Elastase; Male; Middle Aged; Muramidase; Neutrophils; Pancreatic Elastase; Peroxidase; Serine Endopeptidases; Vasculitis

ANCA-positive sera from 1138 patients and ANCA-negative sera from 90 patients were screened for autoantibodies directed against lysozyme (LZ) by ELISA. Sera from 120 patients did react with LZ. 99 sera bound to LZ only, whereas 56 sera bound to further granule proteins, especially cathepsin G and lactoferrin. In the routine ANCA screening, most of the anti-LZ-positive sera showed a pANCA fluorescence. In total, 8% of 674 pANCA-positive sera did react with LZ. Clinically, anti-LZ antibodies were associated inflammatory rheumatologic, -renal and -bowel diseases.

Topics: Antibodies, Antineutrophil Cytoplasmic; Antibody Specificity; Autoantibodies; Glomerulonephritis; Humans; Inflammatory Bowel Diseases; Muramidase; Rheumatic Diseases; Vasculitis

Topics: Antibodies, Antineutrophil Cytoplasmic; Autoantibodies; Blotting, Western; Cathepsin G; Cathepsins; Cytoplasmic Granules; Enzyme-Linked Immunosorbent Assay; Fluorescent Antibody Technique; Humans; Immunoglobulin G; Lactoferrin; Muramidase; Myeloblastin; Neutrophils; Pancreatic Elastase; Peroxidase; Proteins; Serine Endopeptidases; Vasculitis

Own experiences in practical application of immunohistochemistry are demonstrated in cases of lung fibrosis, sarcoidosis, tuberculosis and allergic vasculitis. Methods for demonstration of immunoglobulins (IgG, IgE) are useful in diagnosis of allergic vasculitis (IgG) and allergic alveolitis (IgE). Lysozyme is an important morphological parameter for the estimation of the activity of sarcoidosis. First results of application of antisera against mycobacteria and Kveim antigen are discussed in respect to more precise differential diagnosis of granulomatous lung diseases (sarcoidosis, tuberculosis).

Topics: Alveolitis, Extrinsic Allergic; Antigens, Bacterial; Humans; Immunoglobulins; Immunohistochemistry; Lung; Lung Diseases; Muramidase; Mycobacterium; Pulmonary Fibrosis; Sarcoidosis; Tuberculosis, Pulmonary; Vasculitis