Biomedical subjects

A-K Ulfgren

Publications and source records attributed to A-K Ulfgren.

9 recordsLinked to original sources

PubMed2006

Citrullination is an inflammation-dependent process.

OBJECTIVES: To study the presence of citrullinated proteins in inflammatory conditions and in clinically non-affected tissues of controls. METHODS: Synovial biopsy specimens from 19 patients with rheumatoid arthritis and 10 healthy controls were investigated by immunohistochemistry. Additionally, muscle tissue from 5 patients with polymyositis and from 7 healthy controls, intestinal tissue from macroscopically affected and non-affected areas from 10 patients with inflammatory bowel disease (IBD) and tonsil tissues from 4 chronically inflamed tonsils were studied. RESULTS: Citrullinated proteins were present in all synovial biopsy specimens from patients with rheumatoid arthritis, whereas only three of 10 healthy synovial biopsy specimens showed scarce amounts of citrullination. Citrullination was also present in all myositis-affected muscles, whereas it was absent in the muscle tissues of controls. All tonsil biopsy specimens studied were positive for citrulline. Even though more frequently detected in the macroscopically affected colonic areas, no marked difference was observed in the pattern or extent of citrullination between the macroscopically affected and non-affected intestinal IBD tissues. CONCLUSION: Citrullination is present in a wide range of inflammatory tissues, suggesting that this process is inflammation dependent rather than disease dependent.

Arthritis, Rheumatoid↗

PubMed2005

Standardisation of synovial tissue infiltrate analysis: how far have we come? How much further do we need to go?

Changes in cellular infiltrate and expression of cytokines, chemokines, and cell adhesion molecules as a result of therapeutic interventions in rheumatoid arthritis can be demonstrated in the synovial membrane. However, before synovial tissue analysis can be used as an outcome measure in such studies, standardisation of the site and method of synovial tissue acquisition, methods of tissue processing, and appropriate methods of detection and measurement of cell lineage specific markers and relevant biological proteins is needed.

Arthritis, Rheumatoid↗

PubMed2004

Expression of microsomal prostaglandin E synthase 1 in rheumatoid arthritis synovium.

OBJECTIVE: Microsomal prostaglandin E synthase 1 (mPGES-1) catalyzes the formation of PGE(2) from cyclooxygenase-derived PGH(2). Microsomal PGES-1 is induced by proinflammatory cytokines and is strongly linked to conditions that result in high PGE(2) biosynthesis. PGE(2) contributes to the pathogenesis of rheumatoid arthritis (RA), acting as a mediator of inflammation and promoting bone destruction. Induction of mPGES-1 in rheumatoid synoviocytes by proinflammatory cytokines has been demonstrated in vitro, indicating an important role in RA pathogenesis. Recent studies using mPGES-1-deficient mice demonstrated the importance of this gene in chronic inflammation. The aim of this study was to investigate the expression and localization of mPGES-1 in synovial biopsy specimens obtained from patients with RA. METHODS: Synovial tissue samples from 24 patients with RA were obtained, and immunohistologic analysis was performed using polyclonal antibodies against mPGES-1. Double immunofluorescence staining was performed with antibodies to CD3, CD19, CD20, CD68, CD163, and prolyl 4-hydroxylase. RESULTS: Intracellular mPGES-1 staining was observed in synovial membranes from all of the RA patients studied. Specifically, strong expression of mPGES-1 was detected in synovial lining cells. In sublining mononuclear and fibroblast-like cells, the extent of mPGES-1 staining was less than that in the synovial lining cells. In some patients, positive staining was observed in endothelial cells. With the double immunofluorescence technique, mPGES-1 production was detected in synovial macrophages and fibroblasts, while mPGES-1 expression was not observed in lymphocytes. CONCLUSION: The demonstration of mPGES-1 expression in synovial tissues from patients with RA suggests a role for mPGES-1 in the RA disease process. Microsomal PGES-1 might be a potential new target for treatment strategies to control PGE(2) synthesis in patients with RA, without the systemic side effects associated with cyclooxygenase inhibitors.

Antibody Specificity↗

PubMed2004

Nitric oxide formation in the oropharyngeal tract: possible influence of cigarette smoking.

Cigarette smoking reduces the level of nitric oxide (NO) in exhaled air by an unknown mechanism. The view that part of the effect of cigarette smoking on NO production should occur in the oropharyngeal tract is supported by several studies. We have therefore compared smokers and non-smokers regarding non-enzymatic formation of NO from nitrite in the oral cavity since this is a primary candidate target for cigarette smoke. We have also looked at NO synthase-dependent NO formation in the mucosa of the oropharyngeal tract as an alternative target for the inhibitory effect induced by cigarette smoke. Smokers exhaled 67% lower levels of NO than controls (p<0.01, n=15 each group). We could not detect any significant difference in salivary nitrite, nitrate or ascorbate between smokers and non-smokers. Mouthwash with the antibacterial agent chlorhexidine reduced salivary nitrite (-65%) and exhaled NO levels (-10%) similarly in the two groups. Immunohistochemical techniques revealed dense expression of inducible (but not endothelial or neuronal) NO synthase in the squamous epithelium of non-inflamed tonsillar and gingival tissue biopsies. In the same biopsies, significant Ca2+ -independent citrulline-forming activity was detected. We found no difference between smoking and non-smoking subjects regarding NO-synthase expression and in vitro activity. In another group of non-smoking subjects (n=10), spraying the oropharyngeal tract with the NO-synthase inhibitor NG-monomethyl-L-arginine (250 mg) significantly reduced exhaled NO levels for at least 30 min (-18%, p<0.01). Our data suggest that cigarette smoking does not affect non-enzymatic NO formation from nitrite in saliva. However, NO is also formed by inducible NO synthase in the squamous epithelium of the normal oropharyngeal tract. We suggest that cigarette smoking may down-regulate enzymatic NO formation in the oropharyngeal compartment as well as in the bronchial compartment.

Adult↗

PubMed2003

Inflammatory cell and cytokine patterns in patients with painful clicking and osteoarthritis in the temporomandibular joint.

The occurrence of a subset of cytokines and leukocytes in the posterior disc attachment area of the temporomandibular joint (TMJ) was investigated in two patient groups, i.e, one group with painful clicking and one with osteoarthritis. Synovial biopsies were taken during discectomy in 19 patients with painful clicking and 20 with osteoarthritis. One set of specimens was examined with immunohistochemistry, using frozen sections postfixed by para-formaldehyde and with the cell membranes permeablized in saponin. These sections were incubated with antibodies against cytokines IL-1alpha, IL-1beta, IL-1ra, TNFalpha, IFNgamma, IL2 in all patients and TGFbeta1,2,3 in 16. The other set of specimens was used to characterize cell infiltrates using immunohistochemistry with monoclonal antibodies against antigens CD68 and CD45RO, respectively. Moreover, PCNA was included as a marker for cell proliferation. The cytokine staining was most frequently positive for IL-1alpha and IL-1beta in both patient groups. However, joints with OA showed a more complex cytokine pattern, also involving IFN-gamma (P = 0.019), IL-ra (P = 0.047), and apparently but without reaching the chosen level of significance, IL-2, TNF-alpha and TGF-beta1,2,3. Positive staining for CD45RO was frequent in both groups. OA patients showed more frequently positive staining for CD68 (P = 0.025) and apparently for PCNA.

Antigens, CD↗

PubMed2002

High mobility group box chromosomal protein 1: a novel proinflammatory mediator in synovitis.

OBJECTIVE: High mobility group box chromosomal protein 1 (HMGB-1) is a ubiquitous chromatin component expressed in nucleated mammalian cells. It has recently and unexpectedly been demonstrated that stimulated live mononuclear phagocytes secrete HMGB-1, which then acts as a potent factor that causes inflammation and protease activation. Macrophages play pivotal roles in the pathogenesis of arthritis. The aim of this study was to determine whether synovial macrophage expression of HMGB-1 is altered in human and experimental synovitis. METHODS: Intraarticular tissue specimens were obtained from healthy Lewis rats, Lewis rats with Mycobacterium tuberculosis-induced adjuvant arthritis, and from patients with rheumatoid arthritis (RA). Specimens were immunohistochemically stained for cellular HMGB-1. Extracellular HMGB-1 levels were assessed in synovial fluid samples from RA patients by Western blotting. RESULTS: Immunostaining of specimens from normal rats showed that HMGB-1 was primarily confined to the nucleus of synoviocytes and chondrocytes, with occasional cytoplasmic staining and no extracellular matrix deposition. In contrast, inflammatory synovial tissue from rats with experimental arthritis as well as from humans with RA showed a distinctly different HMGB-1 staining pattern. Nuclear HMGB-1 expression was accompanied by a cytoplasmic staining in many mononuclear cells, with a macrophage-like appearance and an extracellular matrix deposition. Analysis of synovial fluid samples from RA patients further confirmed the extracellular presence of HMGB-1; 14 of 15 samples had HMGB-1 concentrations of 1.8-10.4 microg/ml. CONCLUSION: The proinflammatory mediator HMGB-1 was abundantly expressed as a nuclear, cytoplasmic, and extracellular component in synovial tissues from RA patients and from rats with experimental arthritis. These findings suggest a pathogenetic role for HMGB-1 in synovitis and indicate a new potential therapeutic target molecule.

Adult↗

PubMed2002

The newborn infant is protected by an innate antimicrobial barrier: peptide antibiotics are present in the skin and vernix caseosa.

BACKGROUND: Peptide antibiotics are part of the surface defences against microbial intruders. However, the presence and significance of these innate immune effectors in the skin barrier of the newborn infant have not yet been appreciated. Erythema toxicum neonatorum is an inflammatory skin reaction of unknown aetiology and significance, commonly present in the healthy newborn infant. OBJECTIVES: As peptide antibiotics are upregulated in inflammatory skin disorders, we hypothesized that this also could be the case in erythema toxicum. We also investigated if the vernix caseosa, a cream-like white substance present on the skin of the infant at birth, might contribute to host defences. METHODS: The presence of the human antibacterial peptide LL-37 was investigated by immunohistochemistry and confocal imaging of skin biopsies from four 1-day-old infants with an erythema toxicum rash and four matched newborns without the rash. In addition, we analysed the expression of LL-37 and human beta defensin-1, an antibacterial peptide of epithelial origin, by reverse transcriptase-polymerase chain reaction. Finally, we screened for antibacterial components in vernix material obtained from six healthy newborns by inhibition zone assays. RESULTS: All biopsies from the lesions of erythema toxicum showed a dense, nodular infiltrate with numerous LL-37-expressing cells located in the dermal layer and a clear localization of the peptide within CD15-expressing neutrophils, EG2-expressing eosinophils and CD1a-expressing dendritic cells. LL-37 was also found to be located in CD1a-expressing Langerhans cells and a positive staining for the peptide was seen throughout the whole epidermal layer, both in infants with and without the rash. Skin samples from infants with the rash of erythema toxicum showed a constitutive expression of human beta defensin-1, while the expression of LL-37 seemed to be induced. Furthermore, LL-37 and lysozyme were detected in the protein fractions derived from the vernix caseosa, and these fractions exhibited a clear antibacterial activity. CONCLUSIONS: Peptide antibiotics are present in the vernix caseosa and in the skin of the healthy newborn infant, indicating effective innate immune protection already during fetal and neonatal life.

Anti-Bacterial Agents↗

PubMed2002

Transforming growth factor-beta (TGF-beta) and tissue transglutaminase expression in the small intestine in children with coeliac disease.

The production of cytokines from T cells and macrophages is of potential importance for the histological changes apparent in coeliac disease (CoD). Small intestinal biopsy specimens from children with CoD and disease control subjects were investigated for their content of cytokines and tissue transglutaminase (tTG). The transforming growth factor-beta1 (TGF-beta1) expression was increased in the lamina propria of children with villous atrophy. In contrast, TGF-beta3 was expressed at a higher level in the epithelium and the lamina propria of the disease control subjects. The tTG expression was increased in the small intestine of CoD patients as compared with that in subjects. Interleukin-4 (IL-4) was detected in the lamina propria of both CoD patients and controls, and some of the investigated biopsy specimens also showed IL-4 expression in the epithelium. We conclude that children with active CoD could have an altered expression of TGF-beta and tTG in the small intestine and that a disturbed regulation of TGF-beta may be of importance in the immune pathogenesis of CoD.

Antigens, CD↗

PubMed2002

Anti-tumour necrosis factor (TNF)-alpha therapy (etanercept) down-regulates serum matrix metalloproteinase (MMP)-3 and MMP-1 in rheumatoid arthritis.

OBJECTIVES: Matrix metalloproteinases (MMPs) are cytokine-modulated enzymes that play an important role in the pathogenesis of rheumatoid arthritis (RA) by inducing bone resorption and cartilage destruction. This study evaluated the modulation of serum and synovial MMPs and their inhibitor, tissue inhibitor of matrix metalloproteinases (TIMP)-1, by therapy with soluble tumour necrosis factor (TNF) alpha receptor (etanercept). METHODS: Serum samples were collected from 60 RA patients at baseline and after 8 or 12 weeks of treatment. Paired synovial biopsies were obtained from 11 patients at two time points, before and after 8 weeks of treatment. We measured serum levels of MMP-1, MMP-3 and TIMP-1 by ELISA. Immunohistological analysis of synovial tissue was performed using monoclonal antibodies specific for MMP-1, MMP-3 and TIMP-1. RESULTS: Etanercept therapy significantly down-regulated serum levels of MMP-3 and MMP-1 in parallel with the reduction in inflammatory parameters (C-reactive protein concentration and erythrocyte sedimentation rate) in RA patients. Baseline pretreatment serum levels of MMP-3 correlated with changes in clinical disease activity during therapy. No consistent changes in serum level of TIMP-1 were observed, while ratios of MMP-1 and MMP-3 to TIMP-1 were down-regulated following etanercept treatment. Immunohistochemical analyses revealed great interindividual variability, with generally a high level of expression of MMP and low expression of TIMP. No significant change in the pattern or number of positive cells occurred during therapy. CONCLUSIONS: In RA patients, etanercept therapy down-regulates serum levels of MMP-3 and MMP-1 and the ratio between MMPs and TIMP-1. This may be an important mechanism for the prevention of future development of joint damage.

Adult↗