Recent in vitro and murine in vivo studies have identified several potential LPS tolerance factors. In this study, we describe the expression kinetics of these LPS tolerance factors in standardized human endotoxemia models using i.v. LPS bolus administration. Responsiveness to LPS as well as the expression of potential regulators of LPS signaling were determined in peripheral whole blood. Intravenous LPS administration (4 ng/kg) resulted in peak plasma levels of TNF-α at 1.5 h followed by subsequent peaks of the classic negative feedback inhibitors A20 and IL-10 at 2 and 3 h, respectively. Circulating blood monocyte counts decimated during the initial inflammatory response, but normalized in the period between 4 and 8 h post-LPS. The LPS response as determined by ex vivo TNF release per monocyte in whole blood was profoundly decreased at 6–8 h post-LPS injection despite cessation of A20 and IL-10 expression after 4 h. Analysis of MyD88short, IL-1R-associated kinase (IRAK)-1, IRAK-M, ST2, suppressor of cytokine signaling-1 and -3, SHIP-1, and MAP kinase phosphatase-1 expression indicated that the observed LPS tolerance was associated with decreased IRAK-1 and elevated IRAK-M expression in this human model. Interestingly, a lower dose of LPS (1 ng/kg) induced LPS tolerance accompanied with IRAK-M up-regulation but without depletion of IRAK-1. In vitro studies in whole blood showed that IRAK-M up-regulation by LPS is largely dependent on TNF-α. The observed rise of IRAK-M transcription in the human endotoxemia model appeared much greater compared with in vitro-stimulated whole blood. In conclusion, LPS tolerance in human endotoxemia models is associated with IRAK-M up-regulation.

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We tested the hypothesis that dysfunction of vascular endothelium, indicated by an increase in plasma level of von Willebrand factor (vWF), is present in patients with insulin-dependent diabetes mellitus (IDDM) who develop diabetic nephropathy (DN). DN was classified as absent (urinary albumin excretion [UAE] rate less than 15 microgram/min), incipient (UAE rate 15-200 micrograms/min), or clinical (UAE rate greater than 200 micrograms/min). We followed a cohort of 59 patients for a median of 3 yr. At baseline, 52 patients had no DN, 6 had incipient DN, and 1 had clinical DN. At follow-up, 38 patients had no DN (group 1). Incipient DN had developed in 14 patients and worsened in 3 patients. Clinical DN had worsened in 1 patient. Together, these 18 patients comprised group 2. A decrease in UAE was observed in the remaining three patients with incipient DN at baseline (group 3). In group 1, vWF--measured by immunoelectrophoresis and expressed as a percentage of normal--increased slightly (median 10%, range -43 to 145, P = 0.009). In group 2, vWF increased in all patients (median 80%, range 14 to 206 [corrected], P = 0.0002 vs. baseline and group 1). In group 3, vWF decreased (median -19%, range -44 to -18). After correction for possible confounders, i.e., age, varying duration of follow-up, and initial level of vWF, the difference in vWF change between groups 1 and 2 remained significant (P = 0.009). Poor glycemic control at baseline, estimated by glycosylated hemoglobin, was a significant predictor of increases in vWF in both group 1 and groups 1 and 2 combined.(ABSTRACT TRUNCATED AT 250 WORDS)

A wealth of evidence indicates that plasma levels of high-density lipoprotein cholesterol (HDL-C) are inversely related to the risk of cardiovascular disease (CVD). Consequently, HDL-C has been considered a target for therapy in order to reduce the residual CVD burden that remains significant, even after application of current state-of-the-art medical interventions. In recent years, however, a number of clinical trials of therapeutic strategies that increase HDL-C levels failed to show the anticipated beneficial effect on CVD outcomes. As a result, attention has begun to shift toward strategies to improve HDL functionality, rather than levels of HDL-C per se. ApoA-I, the major protein component of HDL, is considered to play an important role in many of the antiatherogenic functions of HDL, most notably reverse cholesterol transport (RCT), and several therapies have been developed to mimic apoA-I function, including administration of apoA-I, mutated variants of apoA-I, and apoA-I mimetic peptides. Based on the potential anti-inflammatory effects, apoA-I mimetics hold promise not only as anti-atherosclerotic therapy but also in other therapeutic areas.

Rheumatoid arthritis (RA) has been recognized to increase cardiovascular morbidity and mortality independent of established risk factors. The chronic inflammatory state, a hallmark of RA, is considered an autonomous risk factor, whereas components of innate and adaptive immunity are believed to contribute to the onset of acute cardiovascular events. Several studies have suggested that RA confers a prothrombotic state featured by abnormalities in coagulation and fibrinolytic systems together with an altered state of platelet reactivity. It is conceivable that these findings may be partly instrumental for the observed increased risk for adverse cardiovascular events in RA. Therapeutic strategies aimed at attenuating the inflammatory disease activity and intervening at the point of cross-talk between mediators of inflammation and thrombogenesis may help reduce cardiovascular disease burden in patients with RA.