Mighty Bugs: Leprosy Bacteria Turn Schwann Cells into Stem Cells

For intracellular parasites that strongly prefer infecting a particular cell type, systemic spread is challenging. Masaki et al. show that the leprosy bacterium cleverly expands its repertoire by driving dedifferentiation of Schwann cells, their preferred host, to cells with stem cell properties that can subsequently redifferentiate into mesodermal lineages

Erzeugung von Cordierit-Keramikschäumen über die Zwischenstufe hochgefüllter Polyurethan-Schaumstoffe

Der Beitrag berichtet von der Entwicklung von leichten keramischen Massen mit speziellen Schaumstrukturen. Hierzu wurden geeignete Ausgangsstoffe ermittelt sowie ein Verfahren entwickelt, das seine Leistungsfähigkeit mit Keramikformkörpern demonstriert hat. Die Arbeiten beinhalteten im Kern die Entwicklung eines neuartigen Verfahrens der Herstellung keramischer Schaumstoffe mittels PUR-Systemen auf der Basis von Recyclatpolyolen, wobei die keramischen Pulver (u. a. aufbereitete Schlacken und Cordierit-Keramik aus dem Recycling von Abgas-Katalysatoren) in niedrigviskose Polyole eingebracht und anschließend mit Isocyanaten zu anorganisch-organischen Verbundschaumstoffen geschäumt wurden. Die organischen Bestandteile wurden anschließend ausgebrannt und zuletzt die Keramik gesintert. An den erhaltenen Formkörpern wurden mechanische Kennwerte bestimmt, die Strukturen mikroskopisch charakterisiert und Gebrauchswerteigenschaften erfasst. Die entwickelten keramischen Schaumstoffe können als in der Kälte formbeständige Körper für entsprechend belastete Bauteile herangezogen werden und eignen sich zudem als Trägermaterialien für Katalysatoren oder für Aufgaben im Bereich der Filtration.In this paper we report on the development of light ceramic foams of special structures. To this end, suitable raw materials and processing parameters were established to demonstrate the properties and performance of the products. The investigation incorporates the development of a new process to produce foamed ceramics by means of PUR systems based on recycling polyols. Thus, the ceramic powders (amongst others processed slag and cordierite originating from the recycling of car catalysts) were mixed with low viscosity polyols and foamed by the reaction with isocyanates forming structured inorganic-organic composites. In the following step, the organic component was burned out and the ceramic materials simultaneously sintered. Mechanical properties of the resulting ceramic bodies were determined, structures were investigated by microscopicy, and properties for technical use received. The ceramic foams produced are useful to serve as dimensionally stable bodies for low temperature use for special parts in cryogenics, as a substrate for biocatalysts, as precious metal free catalysts in Diesel engine exhaust, or for tasks in the fi eld of fi ltration

Impacts of a new transcription factor family: mammalian GCM proteins in health and disease

GCM proteins constitute a small transcription factor family with a DNA-binding domain exhibiting a novel fold composed of two subdomains rigidly held together by coordination of one of two structural zinc cations. In all known cases, GCM proteins exert the role of master regulators: the prototypical family member determines gliogenesis in Drosophila melanogaster, whereas mammalian GCM proteins orchestrate divergent aspects of development and physiology in placenta, kidney, thymus, and parathyroid gland. Recent data point to an involvement of GCM proteins in different pathological contexts, such as preeclampsia, hyper- or hypoparathyroidism, and parathyroid gland tumors

The POU protein Oct-6 is a nucleocytoplasmic shuttling protein

Like many POU domain proteins, Oct-6 plays important roles during vertebrate development. In accord with its function as a transcriptional regulator during neurogenesis and myelination, Oct-6 is predominantly found in the nucleus. Nuclear import is mediated by a nuclear localization signal at the N-terminal end of the POU homeodomain. Here we show, that Oct-6 in addition contains a nuclear export signal so that Oct-6 is able to shuttle constantly between nucleus and cytoplasm. This nuclear export signal is also localized in the POU homeodomain as part of helix 2 and the connecting loop to DNA recognition helix 3. It conforms to the consensus of hydrophobic leucine-rich export sequences and mediates export from the nucleus via CRM1/Exp1. Several amino acid substitutions or insertions that inactivate this nuclear export sequence, reduce DNA-binding of Oct-6 to its octamer recognition element slighty, but interfere strongly with Oct-6-dependent transcriptional activation, thus arguing that nuclear export and nucleocytoplasmic shuttling are essential aspects of Oct-6 function. Importantly, the nuclear export signal identified for Oct-6 is conserved in most, if not all other vertebrate POU proteins. Nuclear export might therefore be of general relevance for POU protein function throughout development

Olig2 regulates Sox10 expression in oligodendrocyte precursors through an evolutionary conserved distal enhancer

The HMG-domain transcription factor Sox10 is expressed throughout oligodendrocyte development and is an important component of the transcriptional regulatory network in these myelin-forming CNS glia. Of the known Sox10 regulatory regions, only the evolutionary conserved U2 enhancer in the distal 5′-flank of the Sox10 gene exhibits oligodendroglial activity. We found that U2 was active in oligodendrocyte precursors, but not in mature oligodendrocytes. U2 activity also did not mediate the initial Sox10 induction after specification arguing that Sox10 expression during oligodendroglial development depends on the activity of multiple regulatory regions. The oligodendroglial bHLH transcription factor Olig2, but not the closely related Olig1 efficiently activated the U2 enhancer. Olig2 bound U2 directly at several sites including a highly conserved one in the U2 core. Inactivation of this site abolished the oligodendroglial activity of U2 in vivo. In contrast to Olig2, the homeodomain transcription factor Nkx6.2 repressed U2 activity. Repression may involve recruitment of Nkx6.2 to U2 and inactivation of Olig2 and other activators by protein–protein interactions. Considering the selective expression of Nkx6.2 at the time of specification and in differentiated oligodendrocytes, Nkx6.2 may be involved in limiting U2 activity to the precursor stage during oligodendrocyte development

trans-Dichloridobis(triphenyl­phosphane-κP)palladium(II) benzene hemisolvate

The title complex, [PdCl2(C18H15P)2]·0.5C6H6, has the PdII ion in a square-planar coordination mode (r.m.s. deviation for Pd, P and Cl atoms = 0.024 Å) with the PPh3 and Cl ligands mutually trans. The benzene solvent mol­ecule is located about a crystallographic inversion centre. The title complex is isostructural with trans-dichloridobis(triphenyl­phosphane)­palladium(II) 1,4-dichloro­benzene sesquisolvate [Kitano et al. (1983 ▶). Acta Cryst. C39, 1015–1017]