Search results for "Macrophages."
showing 10 items of 530 documents
The effect of Dextransulfate 500 on the pathogenesis of herpes simplex virus infections in weanling mice
1978
Intraperitoneal (i.p.) injection of Dextran Sulfate (D.S.) 500 during a limited period of time influences the course of herpes simplex-virus-infections. D.S.500 was found to reduce the resistance of mice for some herpes simplex-virus strains (Len, L3-2s, Haase) if given between 16 hours before and 2 hours after i.p. infection. The decrease of resistance could be correlated with an increase of the virus content of liver, spleen, brain and spinal cord. Injection of herpes simplex-virus-specific immune serum counteracted the effect of D.S.500 on the course of infections. Conversely, D.S.500 increased the resistance of mice to another group of herpes simplex-viruses (strains D-316, Thea, DD), i…
Advances in detection and characterization of atherosclerosis using contrast agents targeting the macrophage
2006
With advances in imaging technology and our understanding of the role of inflammation in atherosclerosis, the macrophage appears to be an excellent target for imaging the progression of disease. In addition to imaging the macrophage with only 1 modality, contrast agents can be created that can be imaged with multiple modalities. This seems extremely attractive, as lesion morphology and characteristics can be determined with modalities that provide high picture resolution, such as CT or MRI, whereas macrophage quantity can be accurately determined through the creation of a radiolabeled contrast agent such as FDG via PET. Although this combination of imaging technologies may yield clinically …
Cholesterol accumulation is increased in macrophages of phospholipid transfer protein-deficient mice: normalization by dietary alpha-tocopherol suppl…
2007
Objective— Phospholipid transfer protein (PLTP) is a multifunctional, extracellular lipid transport protein that plays a major role in lipoprotein metabolism and atherosclerosis. Recent in vivo studies suggested that unlike systemic PLTP, macrophage-derived PLTP would be antiatherogenic. The present study aimed at characterizing the atheroprotective properties of macrophage-derived PLTP. Methods and Results— Peritoneal macrophages were isolated from PLTP-deficient and wild-type mice and their biochemical characteristics were compared. It is shown that macrophages isolated from PLTP-deficient mice have increased basal cholesterol content and accumulate more cholesterol in the presence of LD…
Inhibition of the NF-κB Signaling Pathway Mediates the Anti-inflammatory Effects of Petrosaspongiolide M
2003
Petrosaspongiolide M (PT) is a potent secretory phospholipase A(2) inhibitor and anti-inflammatory agent. This marine metabolite reduced the production of nitrite, prostaglandin E(2), and tumor necrosis factor-alpha in the mouse air pouch injected with zymosan. These effects were also observed in mouse peritoneal macrophages stimulated with zymosan. Inhibition of these inflammatory mediators was related to reductions in inducible nitric oxide synthase, cyclo-oxygenase-2, and tumor necrosis factor-alpha expression. Since nuclear factor-kappaB (NF-kappaB) appears to play a central role in the transcriptional regulation of these proteins by macrophages, we investigated the effects of PT on thi…
A protective role for interleukin 18 in interferon γ-mediated innate immunity to Cryptosporidium parvum that is independent of natural killer cells.
2012
Innate immunity against some intracellular parasitic protozoa involves interleukin 18 (IL-18)-mediated interferon γ (IFN-γ) production by natural killer (NK) cells, but the role of IL-18 in innate resistance to Cryptosporidium infection is unknown. Adult Rag2(-/-)γc(-/-) mice that lack NK cells, T cells, and B cells demonstrated resistance to Cryptosporidium parvum infection that was IFN-γ dependent. Treatment with anti-IL-18-neutralizing antibodies resulted in loss of resistance correlating with reduced intestinal IFN-γ expression. Intestinal mature IL-18 expression increased in vivo during infection and also in the intestinal epithelial cell line CMT-93 following combined IFN-γ treatment/…
Differential expression of mRNA encoding interleukin-12 p35 and p40 subunitsin situ
1994
Interleukin-12 (IL-12) is a heterodimeric cytokine that plays an important role in the regulation of the immune response. For biological activity the expression of both subunits of IL-12, p35 and p40, is required. Moreover, in the mouse the p40 chain of IL-12 specifically inhibits the effects of the IL-12 heterodimer. In the present study we have analyzed by in situ hybridization the expression of the p35 and p40 mRNA in the spleens of BALB/c and mutant (SCID, nude, beige) mice, unstimulated and after in vivo stimulation with lipopolysaccharide (LPS) and with staphylococcal enterotoxin B (SEB). In unstimulated spleens of BALB/c mice p35 and p40 mRNA were only detectable in a few strongly st…
Silicate modulates the cross-talk between osteoblasts (SaOS-2) and osteoclasts (RAW 264.7 cells): inhibition of osteoclast growth and differentiation
2012
It has been shown that inorganic monomeric and polymeric silica/silicate, in the presence of the biomineralization cocktail, increases the expression of osteoprotegerin (OPG) in osteogenic SaOS-2 sarcoma cells in vitro. In contrast, silicate does not affect the steady-state gene expression level of the osteoclastogenic ligand receptor activator of NF-κB ligand (RANKL). In turn it can be expected that the concentration ratio of the mediators OPG/RANKL increases in the presence of silicate. In addition, silicate enhances the growth potential of SaOS-2 cells in vitro, while it causes no effect on RAW 264.7 cells within a concentration range of 10-100 µM. Applying a co-cultivation assay system,…
An update on the relationships between rheumatoid arthritis and atherosclerosis
2010
Rheumatoid arthritis is a chronic inflammatory disease. Cardiovascular events are the most important cause of mortality and morbidity in patients with rheumatoid arthritis. Beyond the traditional cardiovascular risk factors, chronic systemic inflammation has been shown to be a crucial factor in atherosclerosis development and progression from endothelial dysfunction to plaque rupture and thrombosis. Many studies have shown that atherosclerosis is not a passive event like accumulation of lipids in the vessel walls; by contrast, it represents an active inflammation of the vessels. Inflammatory cells such as macrophages, monocytes and T cells play important roles in the development of both rhe…
Correlative histologic and arthroscopic evaluation in rheumatoid knee joints.
1992
The correlation between arthroscopic observations and histologic changes in rheumatoid arthritis is still controversial. Synovial samples of 21 knee joints in rheumatoid arthritis patients were comparatively investigated by endoscopy and histology. Biopsies were scored by an endoscopist and subsequently dissected. Different histochemical and immunocytochemical staining techniques were used to define inflammatory activity. Arthroscopic and histological values were compared by rating scales and variance analysis. Our study indicates that synovial biopsy is of diagnostic value in rheumatoid arthritis. However, its usefulness depends on the histochemical methods used. The results revealed highl…
Inflammatory cytokines shape a changing DNA methylome in monocytes mirroring disease activity in rheumatoid arthritis
2019
Objective: Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease that mainly targets joints. Monocytes and macrophages are critical in RA pathogenesis and contribute to inflammatory lesions. These extremely plastic cells respond to extracellular signals which cause epigenomic changes that define their pathogenic phenotype. Here, we interrogated how DNA methylation alterations in RA monocytes are determined by extracellular signals. Methods: High-throughput DNA methylation analyses of patients with RA and controls and in vitro cytokine stimulation were used to investigate the underlying mechanisms behind DNA methylation alterations in RA as well as their relationship with clinic…