The molecular checkpoints that drive inflammatory bowel diseases are incompletely understood. Here we found more T cells expressing the transcription factor PU.1 and interleukin 9 (IL-9) in patients with ulcerative colitis. In an animal model, citrine reporter mice had more IL-9-expressing mucosal T cells in experimental oxazolone-induced colitis. IL-9 deficiency suppressed acute and chronic colitis. Mice with PU.1 deficiency in T cells were protected from colitis, whereas treatment with antibody to IL-9 suppressed colitis. Functionally, IL-9 impaired intestinal barrier function and prevented mucosal wound healing in vivo. Thus, our findings suggest that the TH9 subset of helper T cells serves an important role in driving ulcerative colitis by regulating intestinal epithelial cells and that TH9 cells represent a likely target for the treatment of chronic intestinal inflammation.
Background-Adipose tissue is a prominent source of plasminogen activator inhibitor-1 (PAI-1), the primary physiological inhibitor of plasminogen activation. Increased PAI-1 expression acts as a cardiovascular risk factor, and plasma levels of PAI-1 strongly correlate with body mass index (BMI). Elevated serum levels of interleukin-6 (IL-6), an inflammatory cytokine and a member of the glycoprotein 130 (gp130) ligand family, are found in obese patients and might indicate low-grade systemic inflammation. Another gp130 ligand, oncostatin M (OSM), upregulates PAI-1 in cardiac myocytes, astrocytes, and endothelial cells. We used tissue explants and primary cultures of preadipocytes and adipocytes from human subcutaneous and visceral adipose tissue to investigate whether IL-6 and OSM affect PAI-1 expression in fat. Methods and Results-Human subcutaneous and visceral adipose tissue responded to treatment with IL-6 and OSM with a significant increase in PAI-1 production. Human preadipocytes were isolated from subcutaneous and visceral adipose tissue. Adipocyte differentiation was induced by hormone supplementation. All cell types expressed receptors for IL-6 and OSM and produced up to 12-fold increased levels of PAI-1 protein and up to 9-fold increased levels of PAI-1 mRNA on stimulation with IL-6 and OSM. AG-490, a janus kinase/signal transducer and activator of transcription inhibitor, abolished the OSM-dependent PAI-1 induction almost completely. Conclusions-We have for the first time established a link between the gp130 ligands, the proinflammatory mediators IL-6 and OSM, and the expression of PAI-1 in human adipose tissue. Thus, we speculate that IL-6 and OSM, by upregulating PAI-1 in adipose tissue, can contribute to the increased cardiovascular risk of obese patients.
While SCs on vital teeth have the best prognosis, those on endodontically treated teeth have a slightly poorer prognosis over 10 years. Crowns on teeth with post and cores and implant-supported SCs displayed the highest incidence of failures and complications.
We study buffered aqueous solutions of deoxyribonucleic acid isolated from bacteriophage lambda (λ-DNA) at shear rates up to 105 s−1. The shear rates are accessed with a narrow-gap rheometer at gap widths down to 20 μm. At lower shear rates, our data merge with the literature values. At high shear rates, the viscosity levels off into an infinite-shear viscosity plateau. Hence, the viscosity functions of buffered aqueous DNA solutions are now available for the entire shear-rate range from the first Newtonian plateau to that of infinite-shear viscosity. The latter hardly differs from the solvent viscosity. For the normal-stress differences, we observe a power-law dependence on the shear rate close to previous findings up to shear rates of about 104 s−1. Beyond this shear-rate range, we observe a stepwise change with the shear rate. By means of agarose gel electrophoresis, we confirm that the λ-DNA is not fragmented during our rheometric study at high shear rates. Yet, at the highest shear rates studied, shear-induced changes in the DNA to structures not being able to travel through the gel appear.
Crohn's disease (CD) and ulcerative colitis (UC) are the two major forms of inflammatory bowel diseases (IBD), which are defined as relapsing inflammations of the gastrointestinal tract. Cyclosporine A (CsA) is a potential rescue treatment to avoid colectomy in severe steroid-refractory UC patients. The molecular mechanism of action of CsA in UC is nevertheless still not well understood. The aim of this study was to investigate the effect of CsA on a possible modulation of cytokine production by peripheral blood mononuclear cells (PBMCs) of controls and patients with UC or CD. Upon CsA treatment, analyses of cytokine levels revealed a significant reduction of IL-13 expression in PBMCs from patients with UC, whereas other cytokine expression levels remained unaffected. To address the question whether CsA treatment impinges on the induction of cell death, apoptosis assays were performed using CD4? T cells from peripheral blood of patients suffering from either UC or CD. It became clear that CsA treatment resulted in a specific induction of apoptosis in samples from controls and patients with UC but not with CD. Apoptosis induction was not mediated via the mitochondrial apoptosis pathway. The present data support the concept that CsA treatment modulates proinflammatory cytokine production and T cell survival in UC via the induction of apoptosis and might therefore help to explain the clinical efficacy of CsA in patients with UC.
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