MLK3 Limits Activated Gαq Signaling to Rho by Binding to p63RhoGEF

Mixed lineage kinase 3 (MLK3) is a MAP3K that activates the JNK-dependent MAPK pathways. Here we show that MLK3 is required for cell migration in a manner independent of its role as a MAP3K or MLK3 kinase activity. Rather, MLK3 functions in a regulated way to limit levels of the activated GTPase, Rho, by binding to the Rho activator, p63RhoGEF/GEFT, which, in turn, prevents its activation by Gαq. These findings demonstrate a scaffolding role for MLK3 in controlling the extent of Rho activation that modulates cell migration. Moreover, they suggest that MLK3 functions as a network hub that links a number of signaling pathways

Similar NF-κB Gene Signatures in TNF-α Treated Human Endothelial Cells and Breast Tumor Biopsies

BACKGROUND: Endothelial dysfunction has been implicated in the pathogenesis of diverse pathologies ranging from vascular and immune diseases to cancer. TNF-α is one of the mediators of endothelial dysfunction through the activation of transcription factors, including NF-κB. While HUVEC (macrovascular cells) have been largely used in the past, here, we documented an NF-κB gene signature in TNFα-stimulated microvascular endothelial cells HMEC often used in tumor angiogenesis studies. METHODOLOGY/PRINCIPAL FINDINGS: We measured mRNA expression of 55 NF-κB related genes using quantitative RT-PCR in HUVEC and HMEC. Our study identified twenty genes markedly up-regulated in response to TNFα, including adhesion molecules, cytokines, chemokines, and apoptosis regulators, some of them being identified as TNF-α-inducible genes for the first time in endothelial cells (two apoptosis regulators, TNFAIP3 and TNFRSF10B/Trail R2 (DR5), the chemokines GM-CSF/CSF2 and MCF/CSF1, and CD40 and TNF-α itself, as well as NF-κB components (RELB, NFKB1 or 50/p105 and NFKB2 or p52/p100). For eight genes, the fold induction was much higher in HMEC, as compared to HUVEC. Most importantly, our study described for the first time a connection between NF-κB activation and the induction of most, if not all, of these genes in HMEC as evaluated by pharmacological inhibition and RelA expression knock-down by RNA interference. Moreover, since TNF-α is highly expressed in tumors, we further applied the NF-κB gene signature documented in TNFα-stimulated endothelial cells to human breast tumors. We found a significant positive correlation between TNF and the majority (85 %) of the identified endothelial TNF-induced genes in a well-defined series of 96 (48 ERα positive and 48 ERα negative) breast tumors. CONCLUSION/SIGNIFICANCE: Taken together these data suggest the potential use of this NF-κB gene signature in analyzing the role of TNF-α in the endothelial dysfunction, as well as in breast tumors independently of the presence of ERα

Transmembrane TNF-α: structure, function and interaction with anti-TNF agents

Transmembrane TNF-α, a precursor of the soluble form of TNF-α, is expressed on activated macrophages and lymphocytes as well as other cell types. After processing by TNF-α-converting enzyme (TACE), the soluble form of TNF-α is cleaved from transmembrane TNF-α and mediates its biological activities through binding to Types 1 and 2 TNF receptors (TNF-R1 and -R2) of remote tissues. Accumulating evidence suggests that not only soluble TNF-α, but also transmembrane TNF-α is involved in the inflammatory response. Transmembrane TNF-α acts as a bipolar molecule that transmits signals both as a ligand and as a receptor in a cell-to-cell contact fashion. Transmembrane TNF-α on TNF-α-producing cells binds to TNF-R1 and -R2, and transmits signals to the target cells as a ligand, whereas transmembrane TNF-α also acts as a receptor that transmits outside-to-inside (reverse) signals back to the cells after binding to its native receptors. Anti-TNF agents infliximab, adalimumab and etanercept bind to and neutralize soluble TNF-α, but exert different effects on transmembrane TNF-α-expressing cells (TNF-α-producing cells). In the clinical settings, these three anti-TNF agents are equally effective for RA, but etanercept is not effective for granulomatous diseases. Moreover, infliximab induces granulomatous infections more frequently than etanercept. Considering the important role of transmembrane TNF-α in granulomatous inflammation, reviewing the biology of transmembrane TNF-α and its interaction with anti-TNF agents will contribute to understanding the bases of differential clinical efficacy of these promising treatment modalities

The Corynebacterium glutamicum aecD gene encodes a C-S lyase with alpha, beta-elimination activity that degrades aminoethylcysteine

ROSSOL I, Pühler A. The Corynebacterium glutamicum aecD gene encodes a C-S lyase with alpha, beta-elimination activity that degrades aminoethylcysteine. J Bacteriol. 1992;174(9):2968-2977.S-(beta-Aminoethyl)-cysteine (AEC) resistance was achieved in Corynebacterium glutamicum by cloning a chromosomal 1.5-kb EcoRV-BglII DNA fragment on a multicopy plasmid. DNA sequence analysis of the 1.5-kb DNA fragment revealed an open reading frame (ORF326) which represents the AEC resistance gene, designated aecD. The aecD gene directs the synthesis of a 36-kDa protein which was visualized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The aecD gene is a nonessential gene and mediates AEC resistance only in an amplified state. C. glutamicum strains harboring an amplified aecD gene can utilize AEC as an alternative nitrogen source, indicating that the AEC resistance mechanism is due to AEC degradation. Since the AEC degradation products analyzed by high-pressure liquid chromatography were found to be pyruvate and aminoethanethiol (cysteamine), it was concluded that the aecD gene encodes a C-S lyase with alpha,beta-elimination activity. Besides AEC, the C-S lyase was also able to use cysteine, cystine, and cystathionine as substrates

Danger signal extracellular calcium initiates differentiation of monocytes into SPP1/osteopontin-producing macrophages.

The danger signal extracellular calcium is pathophysiologically increased in the synovial fluid of patients with rheumatoid arthritis (RA). Calcium activates the NLRP3-inflammasome via the calcium-sensing receptor in monocytes/macrophages primed by lipopolysaccharide, and this effect is mediated by the uptake of calciprotein particles (CPPs) formed out of calcium, phosphate, and fetuin-A. Aim of the study was to unravel the influence of calcium on monocytes when the priming signal is not present. Monocytes were isolated from the blood of healthy controls and RA patients. Macrophages were characterized using scRNA-seq, DNA microarray, and proteomics. Imaging flow cytometry was utilized to study intracellular events. Here we show that extracellular calcium and CPPs lead to the differentiation of monocytes into calcium-macrophages when the priming signal is absent. Additional growth factors are not needed, and differentiation is triggered by calcium-dependent CPP-uptake, lysosomal alkalization due to CPP overload, and TFEB- and STAT3-dependent increased transcription of the lysosomal gene network. Calcium-macrophages have a needle-like shape, are characterized by excessive, constitutive SPP1/osteopontin production and a strong pro-inflammatory cytokine response. Calcium-macrophages differentiated out of RA monocytes show a stronger manifestation of this phenotype, suggesting the differentiation process might lead to the pro-inflammatory macrophage response seen in the RA synovial membrane

A Gesture-Based Interface for Remote Surgery

International audienceThere has been a great deal of research activity in computer- and robot-assisted surgeries in recent years. Some of the advances have included robotic hip surgery, image-guided endoscopic surgery, and the use of intra-operative MRI to assist in neurosurgery. However, most of the work in the literature assumes that all of the expert surgeons are physically present close to the location of a surgery. A new direction that is now worth investigating is assisting in performing surgeries remotely. As a first step in this direction, this chapter presents a system that can detect movement of hands and fingers, and thereby detect gestures, which can be used to control a catheter remotely. Our development is aimed at performing remote endovascular surgery by controlling the movement of a catheter through blood vessels. Our hand movement detection is facilitated by sensors, like LEAP, which can track the position of fingertips and the palm. In order to make the system robust to occlusions, we have improved the implementation by optimally integrating the input from two different sensors. Following this step, we identify high-level gestures, like push and turn, to enable remote catheter movements. To simulate a realistic environment we have fabricated a flexible endovascular mold, and also a phantom of the abdominal region with the endovascular mold integrated inside. A mechanical device that can remotely control a catheter based on movement primitives extracted from gestures has been built. Experimental results are shown demonstrating the accuracy of the system