Nitric oxide sustains IL-1β expression in human dendritic cells enhancing their capacity to induce IL-17-producing T-cells.

The role played by lung dendritic cells (DCs) which are influenced by external antigens and by their redox state in controlling inflammation is unclear. We studied the role played by nitric oxide (NO) in DC maturation and function. Human DCs were stimulated with a long-acting NO donor, DPTA NONOate, prior to exposure to lipopolysaccharide (LPS). Dose-and time-dependent experiments were performed with DCs with the aim of measuring the release and gene expression of inflammatory cytokines capable of modifying T-cell differentiation, towardsTh1, Th2 and Th17 cells. NO changed the pattern of cytokine release by LPS-matured DCs, dependent on the concentration of NO, as well as on the timing of its addition to the cells during maturation. Addition of NO before LPS-induced maturation strongly inhibited the release of IL-12, while increasing the expression and release of IL-23, IL-1β and IL-6, which are all involved in Th17 polarization. Indeed, DCs treated with NO efficiently induced the release of IL-17 by T-cells through IL-1β. Our work highlights the important role that NO may play in sustaining inflammation during an infection through the preferential differentiation of the Th17 lineage.

Hepatic circadian clock oscillators and nuclear receptors integrate microbiome-derived signals.

The liver is a key organ of metabolic homeostasis with functions that oscillate in response to food intake. Although liver and gut microbiome crosstalk has been reported, microbiome-mediated effects on peripheral circadian clocks and their output genes are less well known. Here, we report that germ-free (GF) mice display altered daily oscillation of clock gene expression with a concomitant change in the expression of clock output regulators. Mice exposed to microbes typically exhibit characterized activities of nuclear receptors, some of which (PPARα, LXRβ) regulate specific liver gene expression networks, but these activities are profoundly changed in GF mice. These alterations in microbiome-sensitive gene expression patterns are associated with daily alterations in lipid, glucose, and xenobiotic metabolism, protein turnover, and redox balance, as revealed by hepatic metabolome analyses. Moreover, at the systemic level, daily changes in the abundance of biomarkers such as HDL cholesterol, free fatty acids, FGF21, bilirubin, and lactate depend on the microbiome. Altogether, our results indicate that the microbiome is required for integration of liver clock oscillations that tune output activators and their effectors, thereby regulating metabolic gene expression for optimal liver function.

A randomized double-blind control study of early intra-coronary autologous bone marrow cell infusion in acute myocardial infarction: the REGENERATE-AMI clinical trial?.

AIMS: Clinical trials suggest that intracoronary delivery of autologous bone marrow-derived cells (BMCs) 1-7 days post-acute myocardial infarction (AMI) may improve left ventricular (LV) function. Earlier time points have not been evaluated. We sought to determine the effect of intracoronary autologous BMC on LV function when delivered within 24 h of successful reperfusion therapy. METHODS AND RESULTS: A multi-centre phase II randomized, double-blind, and placebo-controlled trial. One hundred patients with anterior AMI and significant regional wall motion abnormality were randomized to receive either intracoronary infusion of BMC or placebo (1:1) within 24 h of successful primary percutaneous intervention (PPCI). The primary endpoint was the change in left ventricular ejection fraction (LVEF) between baseline and 1 year as determined by advanced cardiac imaging. At 1 year, although LVEF increased compared with baseline in both groups, the between-group difference favouring BMC was small (2.2%; 95% confidence interval, CI: -0.5 to 5.0; P = 0.10). However, there was a significantly greater myocardial salvage index in the BMC-treated group compared with placebo (0.1%; 95% CI: 0.0-0.20; P = 0.048). Major adverse events were rare in both treatment groups. CONCLUSION: The early infusion of intracoronary BMC following PPCI for patients with AMI and regional wall motion abnormality leads to a small non-significant improvement in LVEF when compared with placebo; however, it may play an important role in infarct remodelling and myocardial salvage. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov NCT00765453 and EudraCT 2007-002144-16.

Enhancement of human adipose-derived stem cell expansion and stability for clinical use

Co-culture techniques associating both dermal fibroblasts and epidermal keratinocytes have shown to have better clinical outcome than keratinocyte culture alone for the treatment of severe burns. Since fat grafting has been shown to improve scar remodelling, new techniques such as cell-therapy-assisted surgical reconstruction with isolated and expanded autologous adipose-derived stem cells (ASCs) would be of benefit to increase graft acceptation. Therefore, integrating ASCs into standardized procedures for cultured skin grafting could be of benefit for the patient if cell quality and quantity could be maintained. The purpose of this study was to evaluate ASC processing from adult tissue with simple isolation (without enzymatic steps), expansion (low density of 325-3,000 cells/cm2) and storage conditions to assure methods to enhance the cellular resistance when transferred back to the patient. Co-culture with cell-banked skin progenitor cells (FE002-SK2) showed an increase of 40-50% ASCs yield at high passages alongside with a better preservation of morphology, proper adipogenic and osteogenic differentiation and efficient biocompatibility with 3D collagen scaffolds. ASCs can be considered as a valuable additional cell source to be delivered in biological bandages to the patient in a need of tissue reconstruction such as burn patients.