Analysis of CD154 and CD40 expression in native coronary atherosclerosis and transplant associated coronary artery disease.

T cells have roles in the pathogenesis of native coronary atherosclerosis (CA) and transplant-associated coronary artery disease (TCAD). The mechanisms by which T cells interact with other cells in these lesions are not fully known. CD154 is an activation-induced CD4+ T cell surface molecule that interacts with CD40+ target cells, including macrophages and endothelial cells, and induces the production of pro-inflammatory molecules, including CD54 (ICAM-1) and CD106 (VCAM-1). To investigate whether CD154-CD40 interactions might be involved in the pathogenesis of CA or TCAD we performed immunohistochemical studies of CD154 and CD40 expression on frozen sections of coronary arteries obtained from cardiac allograft recipients with CA (n=10) or TCAD (n=9). Utilizing four different anti-CD154 mAb we found that CD154 expression was restricted to infiltrating lymphocytes in CA and TCAD. CD40 expression was markedly up-regulated on intimal endothelial cells, foam cells, macrophages and smooth muscle cells in both diseases. Dual immunolabeling demonstrated many CD40+ cells co-expressed CD54 and CD106. The extent of CD40, CD54 and CD106 expression showed statistical significant correlation with the severity of disease and the amount of intimal lymphocytes. Together these studies demonstrate the presence of activated CD154+ and CD40+ cells in both CA and TCAD lesions and suggest that CD154-mediated interactions with CD40+ macrophages, foam cells, smooth muscle cells and/or endothelial cells may contribute to the pathogenesis of these diseases.

Disease pattern recognition testing for rheumatoid arthritis using infrared spectra of human serum.

BACKGROUND: In view of the importance of the diagnosis of rheumatoid arthritis, a novel diagnostic method based on spectroscopic pattern recognition in combination with laboratory parameters such as the rheumatoid factor is described in the paper. Results of a diagnostic study of rheumatoid arthritis employing this method are presented. METHOD: The method uses classification of infrared (IR) spectra of serum samples by means of discriminant analysis. The spectroscopic pattern yielding the highest discriminatory power is found through a complex optimization procedure. In the study, IR spectra of 384 serum samples have been analyzed in this fashion with the objective of differentiating between rheumatoid arthritis and healthy subjects. In addition, the method integrates results from the classification with levels of the rheumatoid factor in the sample by optimized classifier weighting, in order to enhance classification accuracy, i.e. sensitivity and specificity. RESULTS: In independent validation, sensitivity and specificity of 84% and 88%, respectively, have been obtained purely on the basis of spectra classification employing a classifier designed specifically to provide robustness. Sensitivity and specificity are improved by 1% and 6%, respectively, upon inclusion of rheumatoid factor levels. Results for less robust methods are also presented and compared to the above numbers. CONCLUSION: The discrimination between RA and healthy by means of the pattern recognition approach presented here is feasible for IR spectra of serum samples. The method is sufficiently robust to be used in a clinical setting. A particular advantage of the method is its potential use in RA diagnosis at early stages of the disease.

Topiramate and physiologic measures of nerve function in polyneuropathy.

OBJECTIVE: To evaluate topiramate treatment on nerve function using electrophysiologic methods and a non-inferiority clinical trial design. METHODS: A double-blind, multicenter, placebo-controlled trial was conducted in patients with painful diabetic polyneuropathy (n = 67). Change in peroneal motor nerve conduction velocity (NCV) was the primary outcome. NCVs of sural sensory and ulnar nerves, and amplitude and latency changes were measured secondarily. Peripheral nerve function was also evaluated in a patient subgroup reporting treatment-emergent paresthesias. RESULT: Least squares mean decrease in NCV was greater for placebo (-0.2 m/s) than for topiramate treatment (-0.1 m/s) (95% CI: -1.30, 1.42). Secondary measures showed no decrease in nerve function for topiramate-treated patients. Neurophysiologic measures were similar in patients with and without paresthesias. The most common adverse events with topiramate were paresthesias, anorexia, weight decrease, and taste perversion. CONCLUSION: This nerve conduction study found no evidence that topiramate is associated with deterioration of nerve function.

T cells in the pathogenesis of systemic lupus erythematosus: potential roles of CD154-CD40 interactions and costimulatory molecules.

CD154 is an activation-induced CD4+ T cell surface molecule that interacts with CD40 on antigen-presenting cells (APC) and upregulates the key costimulatory molecules, CD80 and CD86. Bidirectional intercellular signaling mediated by CD40 ligation and CD80/CD86 interactions with counter-receptors on T cells play central roles in regulating the survival and outgrowth of pathogenic autoreactive T cells and B cells in systemic lupus erythematosus (SLE). CD40 is also expressed on a variety of other cells, including endothelial cells and renal tubule epithelial cells. CD154 activation of APCs, endothelial cells, and renal tubular epithelial cells have proinflammatory or procoagulant effects that may contribute to the pathogenesis of lupus. This review will focus on the immunobiology of CD154-CD40 interactions and the costimulatory functions of CD80 and CD86. The experimental evidence suggesting roles for these molecules in the immunopathogenesis of SLE will be reviewed.

Molecular characterization of the diurnal/circadian expression of the chlorophyll a/b-binding proteins in leaves of tomato and other dicotyledonous and monocotyledonous plant species.

Diurnal oscillations of steady-state mRNA levels encoding the chlorophyll a/b-binding proteins were monitored inLycopersicon esculentum, Glycine max, Phaseolus vulgaris, P. aureus, P. coccineus, Pisum sativum, Sinapis alba, Hordeum vulgare, Triticum aestivum andZea mays. In these plant speciescab mRNA accumulation increases and decreases periodically indicating i) that the expression of the genes for chlorophyll a/b-binding proteins (cab genes) is controlled by a circadian rhythm, and ii) that the rhythm is widely distributed among monocotyledonous and dicotyledonous plant species. A detailed characterization of the pattern ofcab mRNA expression in tomato leaves shows that the amplitude of the oscillation is dependent on i) the developmental stage of the leaves, ii) the circadian phase and duration of light and iii) the circadian phase and duration of darkness. In addition to the chlorophyll a/b-binding proteins, genes coding for other cellular functions were examined for cyclic variations of their mRNA levels. The analysis includes genes involved in i) carbon metabolism (e.g. phosphoenolpyruvate carboxylase, pyruvate orthophosphate dikinase, alpha amylase, fructose-1,6-bisphosphate aldolase, triosephosphate isomerase), ii) photosynthesis (large and small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase, QB-binding protein, reaction-center protein of photosystem I) and iii) other physiological or morphological reactions (e.g. ubiquitin, actin). However, no periodic fluctuation pattern was detected for the mRNA levels of these genes in tomato and maize leaves.

CD40 ligation triggers COX-2 expression in endothelial cells: evidence that CD40-mediated IL-6 synthesis is COX-2-dependent.

OBJECTIVE: To investigate whether CD40-CD154 interactions on HUVEC can trigger COX-2 synthesis as well as PGE2 and PGI2 secretion in vitro and explore whether the CD40-triggered prostanoids provide costimulatory signals for IL-6 secretion in this cell type. MATERIALS AND METHODS: COX-2 protein expression was examined in HUVEC using Western blot analysis. ELISAs were employed to assess PGE2, PGI2 and IL-6 synthesis. RESULTS: We found that COX-2 expression is upregulated when HUVEC are cultured with CD154+ D1.1 cells but not CD154- B2.7 cells. This effect was specifically inhibited by anti-CD154 mAb, and was amplified by the presence of IFNgamma. Analysis of cell supernatants showed a concomitant rise in PGE2 and PGI2 secretion triggered by CD154+ D1.1 cells, or rsCD154. Use of selective (NS-398) and non-selective (ibuprofen) COX-2 inhibitors effectively inhibited prostanoid synthesis triggered by CD40 ligation. Reduction in prostanoid levels by NS-398 was accompanied by a reduction in IL-6 secretion levels triggered by CD40 ligation. Furthermore, exogenously added PGE2 triggered a dose-dependent IL-6 secretion, which was unaffected by NS-398. CONCLUSIONS: These studies demonstrate that CD40 ligation upregulates HUVEC COX-2 expression and function. Moreover, the data strongly suggest that CD154-induced IL-6 secretion in HUVEC is dependent on COX-2 activity.

Topiramate in painful diabetic polyneuropathy: findings from three double-blind placebo-controlled trials.

OBJECTIVES: To evaluate the efficacy and tolerability of topiramate in patients with painful diabetic polyneuropathy. MATERIALS AND METHODS: Patients with moderate to extreme pain (0-4 Categorical Pain Scale score > or = 2) were randomized to placebo or topiramate (100, 200, or 400 mg/day) in three similar double-blind trials. The primary efficacy analysis was pain reduction from final visit to baseline in the 100-mm Visual Analog Scale (VAS) for the intent-to-treat populations. RESULTS: After 18-22 weeks of double-blind treatment, pain reductions were numerically greater with topiramate in two studies but differences between topiramate and placebo in VAS scores or in the secondary efficacy endpoints did not reach statistical significance in any of the three studies. Across all studies, 24% of topiramate-treated patients and 8% of placebo-treated patients discontinued due to adverse events; groups did not differ in the occurrence of serious adverse events. CONCLUSION: These studies did not find topiramate to be significantly more effective than placebo in reducing pain scores in patients with painful diabetic polyneuropathy. Several design features may have precluded the studies from having sufficient sensitivity to differentiate effective and ineffective treatments. The study design and results are instructive for other investigators designing future clinical studies in neuropathic pain.

CD154 (CD40L) induces human endothelial cell chemokine production and migration of leukocyte subsets.

CD154-CD40 interactions play key roles in humoral and cellular immune responses. With regard to the latter, ligation of CD40 on endothelial cells upregulates important intercellular adhesion molecules. Activated endothelial cells also regulate leukocyte trafficking into inflammatory sites by secreting chemokines. In this study we asked whether CD154 mediated signals induce human umbilical vein endothelial cells (HUVEC) to secrete neutrophil or peripheral blood mononuclear cell (PBMC) chemoattractants. HUVEC were cocultured with CD154(+) Jurkat D1.1 cells in the presence or in the absence of anti-CD154 mAb or control mAb. Additionally, HUVEC were cocultured with control CD154(-) Jurkat B2.7 cells. Supernatants were harvested after 24 h and chemotaxis assays performed. Supernatants derived from Jurkat cells did not induce either neutrophil or PBMC chemotaxis. Resting endothelial cells produce at baseline some neutrophil and PBMC chemoattractants. However, there was significantly enhanced neutrophil and PBMC chemoattractant activity in supernatants derived from CD154 stimulated HUVEC. The enhanced leukocyte migration was specifically inhibited by anti-CD154 mAb. Anti-chemokine mAbs were used to identify specific chemokines mediating the enhanced leukocyte chemotaxis activity in CD154 stimulated HUVEC supernatants. There was complete or near complete inhibition of enhanced neutrophil and PBMC migration by anti-IL-8 and anti-monocyte chemoattractant protein-1 (MCP-1) mAbs, respectively. Anti-RANTES mAb partially blocked the enhanced PBMC migration, whereas anti-macrophage inflammatory protein-1alpha (MIP-1alpha) mAb had no effect. Utilizing specific ELISAs, we confirmed that CD40 ligation induces HUVEC to secrete IL-8, MCP-1, and RANTES, but not MIP-1alpha. Finally, we present evidence that the effects of CD154-CD40 interactions on HUVEC chemokine production are independent of IL-1beta production. These findings demonstrate that CD154-CD40 interactions induce endothelial cells to produce specific neutrophil and mononuclear cell chemoattractants.