The aim of the study was to describe the incidence and progression of retinal drusen, retinal pigmentary abnormalities, and signs of late age-related maculopathy.
A population of 3583 adults (range, ...43-86 years of age at baseline) living in Beaver Dam, Wisconsin, was studied during a 5-year period.
Characteristics of drusen and other lesions typical of age-related maculopathy were determined by grading stereoscopic color fundus photographs using the Wisconsin Age-Related Maculopathy Grading System.
There was a statistically significant increased incidence of age-related maculopathy lesions with age (P < 0.05). Individuals 75 years of age or older had a significantly (P < 0.01) higher 5-year incidence of the following characteristics than people 43 to 54 years of age: larger sized drusen (125-249 microm, 17.6% vs. 2.1%; > or = 250 microm, 6.5% vs. 0.2%), soft indistinct drusen (16.3% vs. 1.8%), retinal pigment abnormalities (12.9% vs. 0.9%), exudative macular degeneration (1.8% vs. 0%), and pure geographic atrophy (1.7% vs. 0%). After adjusting for age, the incidence of early age-related maculopathy was 2.2 times (95% confidence interval 1.6, 3.2) as likely in women 75 years of age or older compared with men this age. At follow-up, late age-related macular degeneration was more likely to develop in eyes with soft indistinct drusen (6.5% vs. 0.1%) or retinal pigmentary abnormalities (7.1% vs. 0.1%) at baseline than in eyes without these lesions.
These population-based estimates document the high incidence of signs of age-related maculopathy in people 75 years of age or older, and in women compared with men that age. The findings demonstrate that the presence of soft drusen and pigmentary abnormalities significantly increases the risk for the development of geographic atrophy and exudative macular degeneration.
Both epithelial barrier dysfunction and apoptosis resistance of immune cells contribute to the pathogenesis of Crohn's disease. The soluble decoy receptor 3 (DcR3) acts in an anti-apoptotic manner by ...neutralising the death ligand CD95L. Here, we investigated the possible involvement of DcR3 in Crohn's disease.
The epithelial fraction of human small intestinal mucosa samples was obtained by laser microdissection. Expression of DcR3 was examined by global gene expression profiling, quantitative reverse transcription polymerase chain reaction, immunoblot analysis, and immunohistochemistry. DcR3 concentrations in the serum of patients with Crohn's disease were measured by enzyme-linked immunosorbent assay. Apoptosis assays were performed to study the effects of DcR3 in intestinal epithelial cells and lamina propria T cells.
DcR3 is over-expressed in the epithelial layer of ileum specimens in patients with Crohn's disease, both at actively inflamed and non-active sites. DcR3 serum levels are significantly elevated in patients with active and non-active Crohn's disease as compared to healthy controls. The expression of DcR3 in intestinal epithelial cells is induced by tumour necrosis factor alpha. Increased DcR3 expression is associated with activation of nuclear factor kappa B (NF-kappaB) and results in protection of intestinal epithelial cells and lamina propria T cells from CD95L-induced apoptosis.
DcR3 may promote inflammation in Crohn's disease by inhibiting CD95L-induced apoptosis of epithelial and immune cells as well as by inducing NF-kappaB activation.
Cofilin, an actin‐depolymerizing protein, is essential for the functional dynamics of the actin cytoskeleton and for cell viability. In unstimulated human peripheral blood T lymphocytes cofilin is ...phosphorylated and localized in the cytoplasm. Following co‐stimulation through accessory receptors (e.g. CD2 or CD28) – however, not following TCR/CD3 stimulation alone – cofilin undergoes dephosphorylation. The subcellular localization as well as the actin‐binding activity of cofilin are regulated by the phosphorylation state of serine‐3. Thus, only the dephosphorylated form of cofilin associates with the actin cytoskeleton and possesses the capability to translocate into the nucleus. Recently, LIM‐kinase 1 was shown to inactivate cofilin through phosphorylation. Here, we have identified the functional counterparts of LIM‐kinase 1: the serine/threonine phosphatases of type 1 and type 2A not only associate with cofilin but also dephosphorylate this 19‐kDa protein and thereby mediate cofilin activation. In malignant T lymphoma cells, activation of these phosphatases occurs spontaneously, independent of external stimuli. In untransformed human peripheral blood T lymphocytes, these phosphatases function through a cyclosporin A/FK506‐resistant co‐stimulatory signaling pathway which is common for the accessory receptors CD2 and CD28. This co‐stimulatory signaling pathway is also not affected by a series of other clinically established immunosuppressive drugs (i.e. rapamycin, dexamethasone, leflunomide or mycophenolic acid).
The formation of supramolecular activation clusters within the immunological synapse, crucial for sustained signaling and T lymphocyte activation, requires costimulation-dependent reorganization of ...the actin cytoskeleton. Here we have identified the actin-remodeling protein cofilin as a key player in this process. Cell-permeable peptides that block costimulation-induced cofilin/F-actin interactions in untransformed human T lymphocytes impair receptor capping and immunological synapse formation at the interface between T cells and antigen-presenting cells. As a consequence, T cell activation, as measured by cytokine production and proliferation, is inhibited.
A dysregulated secretion of contra-inflammatory cytokines such as interleukin-10 (IL-10) could play a role in the pathogenesis of inflammatory bowel disease (IBD). We have investigated the expression ...of IL-10 in gut tissues from patients with Crohn's disease (CD), ulcerative colitis (UC) and controls by mRNA
in situhybridization and immunohistochemistry. Intestinal epithelial cells were found to express IL-10 mRNA and IL-10 protein in all of the tissues investigated without any major differences in the expression patterns. However, compared with noninflamed gut, significantly increased numbers of mononuclear cells (MNCs) producing IL-10 were present in inflamed gut, both in CD and UC. This cytokine was expressed most prominently by inflammatory infiltrates enriched in macrophages, although T cells seem to contribute to its production as well. Elevated IL-10 expression in IBD was mainly detected in the submucosa, whereas IL-10 production by lamina propria cells remained comparably low. In contrast, the expression of IL-1β mRNA was preferentially increased in the lamina propria. Our data argue against a general deficiency in IL-10 production in IBD. The results suggest rather that the local production of IL-10 by mucosal MNCs in IBD is insufficient to down-regulate pro-inflammatory cytokines such as IL-1β in the lamina propria compartment.
Background: It has been suggested that Crohn's disease (CD) is associated with an exaggerated T‐helper 1 cytokine response manifested by increased production of interleukin (IL)‐12. IL‐12 is a ...heterodimeric protein comprising 2 disulfide‐linked subunits designated p35 and p40. Recently, IL‐12‐related cytokines, IL‐23 and IL‐27, were described. Biologically active IL‐23 is a heterodimer whose p40 subunit is identical to IL‐12p40 whereas its p19 subunit is distantly related to IL‐12p35. IL‐27 consists of EBI3, an IL‐12p40‐related protein, and p28, a newly discovered IL‐12p35‐related polypeptide.
Aim: We sought to determine whether mucosal expression of IL‐23p19 and IL‐27p28 transcripts correlate with the inflammatory activity in inflammatory bowel disease (IBD).
Patients/Methods: Messenger RNA expression in colonic mucosa from patients with Crohn's disease (CD; n = 37) and ulcerative colitis (UC; n = 19), and in non‐IBD control subjects (specific colitis SC; n = 16) and normal, nondiseased control patients (n = 12) was measured by reverse‐transcribed real‐time polymerase chain reaction.
Results: IL‐23p19 was significantly increased in inflamed mucosa in CD (P = 0.0377) and to a lesser extent also in UC patients but not in SC patients. Elevation of IL‐23p19 transcript levels in CD correlated with the severity of endoscopic lesions. IL‐27p28 transcripts and EBI3 transcripts were significantly elevated only in active CD.
Discussion: IL‐23p19, IL‐27p28, and EBI3 transcripts are strongly up‐regulated in CD. The stimulatory effects of these cytokines on naive T cells in addition to a strongly synergistic action with IL‐12 to trigger interferon‐γ production may contribute to the perpetuation of the inflammatory process in patients with CD. Notably, increased expression of IL‐23 and IL‐27 transcripts in CD suggests a T helper 1‐dominated immunologic function in this disease.
: Background: Detection of cardiac allograft rejection is based on the histological examination of endomyocardial biopsies (EMB). We have explored the possibility of whether graft rejection could ...be detected by characteristic gene expression patterns in peripheral blood mononuclear cells (PBMC) of heart‐transplant recipients.
Methods: The study included 58 blood samples of 44 patients. On the day of EMB, mononuclear cells were isolated from peripheral blood, and gene expression was measured by quantitative real‐time PCR. Thirty‐nine parameters, including cytokine and chemokine genes were analyzed. Gene expression results were correlated with histological assessment of concomitant evaluated EMB according to International Society for Heart and Lung Transplantation (ISHLT) nomenclature.
Results: Gene expression of perforin, CD95 ligand, granzyme B, RANTES, CXCR3, COX2, ENA 78 and TGF‐β1 was significantly different in PBMC of patients with mild to moderate degrees of allograft rejection (≥grade 2) compared with patients exhibiting no or minor forms of rejection (<grade 2). Using discriminance analysis, five parameters were found that allow discrimination of rejection ≥grade 2 vs. <grade 2 with a sensitivity of 84% and a specificity of 82% as assessed by receiver operating characteristic analysis.
Conclusion: Quantitative analysis of gene expression in PBMC may be a valuable tool for non‐invasive diagnosis of allograft rejection and may allow further insight in the biological process of graft rejection.
Human intestinal lamina propria T lymphocytes (LPT), when investigated ex vivo, exhibit functional properties profoundly different from those of peripheral blood T lymphocytes (PBT). One prominent ...feature represents their enhanced sensitivity to CD2 stimulation when compared to PBT. Given that LPT are hyporesponsive to T cell receptor (TCR)/CD3 stimulation, an alternative activation mode, as mimicked by CD2 triggering in vitro, may be functional in mucosal inflammation in vivo. This study provides insight into signalling events associated with the high CD2 responsiveness of LPT. When compared to PBT, LPT show an increased activation of the phosphoinositide 3/protein kinase B/glycogen synthase kinase 3β (PI3-kinase/AKT/GSK-3β) pathway in response to CD2 stimulation. Evidence is provided that up-regulation of this pathway contributes to the enhanced CD2-induced cytokine production in LPT. Given the importance of TCR-independent stimulation for the initiation of intestinal immune responses analysis of signalling pathways induced by 'co-stimulatory' receptors may provide valuable information for therapeutic drug design.
Signal transduction processes in T-cells and other cell types alter the phosphorylation state of cofilin, an actin-binding
phosphoprotein. Whether reversible phosphorylation is responsible for the ...regulation of the functional activities of cofilin
is not clear at present. Here we have identified the phosphoacceptor site of cofilin and analyzed the role of cofilin phosphorylation
with respect to its subcellular localization. Site-directed mutagenesis studies show that phosphorylation occurs exclusively
on Ser-3. Expression of non-phosphorylatable mutant cofilin proteins in NIH3T3 cells and determination of their subcellular
localization by confocal laser scanning microscopy reveal that non-phosphorylated cofilin accumulates within nuclei. This
analysis shows that the subcellular localization of cofilin depends on the phosphorylation state of Ser-3.
After ileopouch anal anastomosis (IPAA), 10-40% of patients with ulcerative colitis (UC) but only 5% of patients with familial adenomatous polyposis (FAP) develop pouchitis. Immunoregulatory ...abnormalities might be of importance in the pathogenesis of the disease. Therefore, we characterized cytokine and chemokine transcripts in inflamed and non-inflamed pouches in patients with UC compared to those with FAP and Crohn's disease (CD).
Mucosal biopsies were taken from 87 patients with IPAA UC (n=70), CD (n=8) or FAP (n=9). Patients with active ileal CD (n=14), active UC (n=17) and non-inflammatory conditions (n=12) served as controls. The expression of 20 gene transcripts was quantified using real-time polymerase chain reaction.
Pro-inflammatory cytokines and chemokines are significantly increased in IPAA patients with acute pouchitis. This increase is independent of the underlying disease (UC or CD) and reflects the degree of inflammation. A good correlation between pouchitis activity (using the Pouchitis Disease Activity Index) and the MRP-14, interleukin-8, macrophage inflammatory protein-2alpha and matrix metalloproteinase-1 transcripts was observed.
Our data support the view that pouchitis reflects an inflammatory process that is different from that of underlying inflammatory bowel diseases, as the cytokine and chemokine patterns in pouchitis are neither typical of CD nor of UC, but maybe due to bacterial intestinal microflora overgrowth in the pouch lumen. Quantification of transcript levels allows an estimation of the extent of mucosal inflammation and may become helpful in the evaluation of the disease, especially in clinical trials.
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