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Nasal colonization is a major risk factor for S. aureus infections. The mechanisms responsible for colonization are still not well understood and involve several factors on the host and the bacterial side. One key factor is the cell wall teichoic acid (WTA) of S. aureus, which governs direct interactions with nasal epithelial surfaces. We report here the first receptor for the cell wall glycopolymer WTA on nasal epithelial cells. In several assay systems this type F-scavenger receptor, termed SREC-I, bound WTA in a charge dependent manner and mediated adhesion to nasal epithelial cells in vitro. The impact of WTA and SREC-I interaction on epithelial adhesion was especially pronounced under shear stress, which resembles the conditions found in the nasal cavity. Most importantly, we demonstrate here a key role of the WTA-receptor interaction in a cotton rat model of nasal colonization. When we inhibited WTA mediated adhesion with a SREC-I antibody, nasal colonization in the animal model was strongly reduced at the early onset of colonization. More importantly, colonization stayed low over an extended period of 6 days. Therefore we propose targeting of this glycopolymer-receptor interaction as a novel strategy to prevent or control S. aureus nasal colonization.
Background: Gastric cancers have poor overall survival despite recent advancements in early detection methods, endoscopic resection techniques, and chemotherapy treatments. Vaccinia viral therapy has had promising therapeutic potential for various cancers and has a great safety profile. We investigated the therapeutic efficacy of a novel genetically-engineered vaccinia virus carrying the human sodium iodide symporter (hNIS) gene, GLV-1 h153, on gastric cancers and its potential utility for imaging with Tc-99m pertechnetate scintigraphy and I-124 positron emission tomography (PET).
Methods: GLV-1 h153 was tested against five human gastric cancer cell lines using cytotoxicity and standard viral plaque assays. In vivo, subcutaneous flank tumors were generated in nude mice with human gastric cancer cells, MKN-74. Tumors were subsequently injected with either GLV-1 h153 or PBS and followed for tumor growth. Tc-99m pertechnetate scintigraphy and I-124 microPET imaging were performed.
Results: GFP expression, a surrogate for viral infectivity, confirmed viral infection by 24 hours. At a multiplicity of infection (MOI) of 1, GLV-1 h153 achieved > 90% cytotoxicity in MNK-74, OCUM-2MD3, and AGS over 9 days, and >70% cytotoxicity in MNK-45 and TMK-1. In vivo, GLV-1 h153 was effective in treating xenografts (p < 0.001) after 2 weeks of treatment. GLV-1 h153-infected tumors were readily imaged by Tc-99m pertechnetate scintigraphy and I-124 microPET imaging 2 days after treatment.
Conclusions: GLV-1 h153 is an effective oncolytic virus expressing the hNIS protein that can efficiently regress gastric tumors and allow deep-tissue imaging. These data encourages its continued investigation in clinical settings.
Accumulated common variants in the broader fragile X gene family modulate autistic phenotypes
(2015)
Fragile X syndrome (FXS) is mostly caused by a CGG triplet expansion in the fragile X mental retardation 1 gene (FMR1). Up to 60% of affected males fulfill criteria for autism spectrum disorder (ASD), making FXS the most frequent monogenetic cause of syndromic ASD. It is unknown, however, whether normal variants (independent of mutations) in the fragile X gene family (FMR1, FXR1, FXR2) and in FMR2 modulate autistic features. Here, we report an accumulation model of 8 SNPs in these genes, associated with autistic traits in a discovery sample of male patients with schizophrenia (N = 692) and three independent replicate samples: patients with schizophrenia (N = 626), patients with other psychiatric diagnoses (N = 111) and a general population sample (N = 2005). For first mechanistic insight, we contrasted microRNA expression in peripheral blood mononuclear cells of selected extreme group subjects with high-versus low-risk constellation regarding the accumulation model. Thereby, the brain-expressed miR-181 species emerged as potential "umbrella regulator", with several seed matches across the fragile X gene family and FMR2. To conclude, normal variation in these genes contributes to the continuum of autistic phenotypes.
Merkel cell carcinoma (MCC) is a highly aggressive skin cancer with an increasing incidence. The understanding of the molecular carcinogenesis of MCC is limited. Here, we scrutinized the PI3K/AKT pathway, one of the major pathways activated in human cancer, in MCC. Immunohistochemical analysis of 41 tumor tissues and 9 MCC cell lines revealed high levels of AKT phosphorylation at threonine 308 in 88% of samples. Notably, the AKT phosphorylation was not correlated with the presence or absence of the Merkel cell polyoma virus (MCV). Accordingly, knock-down of the large and small T antigen by shRNA in MCV positive MCC cells did not affect phosphorylation of AKT. We also analyzed 46 MCC samples for activating PIK3CA and AKT1 mutations. Oncogenic PIK3CA mutations were found in 2/46 (4%) MCCs whereas mutations in exon 4 of AKT1 were absent. MCC cell lines demonstrated a high sensitivity towards the PI3K inhibitor LY-294002. This finding together with our observation that the PI3K/AKT pathway is activated in the majority of human MCCs identifies PI3K/AKT as a potential new therapeutic target for MCC patients.
The role of serum amyloid A (SAA) proteins, which are ligands for toll-like receptors, was analyzed in human bone marrow-derived mesenchymal stem cells (hMSCs) and their osteogenic offspring with a focus on senescence, differentiation andmineralization. In vitro aged hMSC developed a senescence-associated secretory phenotype (SASP), resulting in enhanced SAA1/2, TLR2/4 and proinflammatory cytokine (IL6, IL8, IL1\(\beta\), CXCL1, CXCL2) expression before entering replicative senescence. Recombinant human SAA1 (rhSAA1) induced SASP-related genes and proteins in MSC, which could be abolished by cotreatment with the TLR4-inhibitor CLI-095. The same pattern of SASP-resembling genes was stimulated upon induction of osteogenic differentiation, which is accompanied by autocrine SAA1/2 expression. In this context additional rhSAA1 enhanced the SASP-like phenotype, accelerated the proinflammatory phase of osteogenic differentiation and enhanced mineralization. Autocrine/paracrine and rhSAA1 via TLR4 stimulate a proinflammatory phenotype that is both part of the early phase of osteogenic differentiation and the development of senescence. This signaling cascade is tightly involved in bone formation and mineralization, but may also propagate pathological extraosseous calcification conditions such as calcifying inflammation and atherosclerosis.
Das Enzym alpha-Dioxygenase (alpha-DOX) aus Erbsen (Pisum sativum) wurde mit folgenden Zielsetzungen untersucht: Isolierung und Charakterisierung der für die P. sativum alpha-DOX codierenden cDNA, Überproduktion der P. sativum alpha-DOX in Escherichia coli und nachfolgende Isolierung, Untersuchung der Interaktion der P. sativum alpha-DOX mit Fettsäuresubstraten sowie systematische Studie der Expression der P. sativum alpha-DOX während der Keimung und Entwicklung von Erbsenpflanzen. alpha-Dioxygenasen katalysieren in Pflanzen den Initialschritt der alpha-Oxidation von langkettigen Fettsäuren, die über die intermediäre Bildung von (R)-2-Hydroperoxyfettsäuren führt. Folgeprodukte dieser Reaktion sind die entsprechende (R)-2-Hydroxysäure sowie der um ein C-Atom kettenverkürzte Aldehyd. Es wurde die für die alpha-Dioxygenase aus Erbsen codierende cDNA mit einer Gesamtlänge von 2132 bp isoliert, die ein offenes Leseraster von 1929 bp beinhaltet. Sie codiert für ein Protein mit 643 Aminosäuren und einem errechneten Molekulargewicht von ca. 73 kD. Die Pisum sativum alpha-Dioxygenase wurde in E. coli als Fusionsprotein mit einem 6 x His-tag überproduziert und mittels Metallaffinitätschromatographie an Ni-NTA-Agarose isoliert. Studien zur Interaktion der P. sativum alpha-Dioxygenase mit Fettsäuresubstraten umfassten sowohl Versuche zu Anforderungen auf Seiten des Substrats als auch zu potentiellen Interaktionspartnern auf Seiten des Enzym. Es wurde gezeigt, dass für die Reaktion von alpha-Dioxygenasen mit Fettsäuren die freie Carboxylgruppe des Substrats unerlässlich ist. Aufgrund eines Aminosäuresequenzvergleichs zwischen der alpha-Dioxygenase aus Erbsen und PGHS-1 aus O. aries wurden vier Aminosäuren als potentielle Interaktionspartner auf Seiten der alpha-Dioxygenase aus Erbsen ausgewählt. Es handelte sich um die Arginin-Reste Arg-87, Arg-391, Arg-569 und Arg-570. Mit Hilfe der ortsspezifischen Mutagenese wurde gezeigt, dass der Aminosäurerest Arg-570 für die katalytische Aktivität unerlässlich ist. Die Expression der P. sativum alpha-Dioxygenase in keimenden Erbsen und jungen Erbsenpflanzen wurde sowohl in ihrem zeitlichen Verlauf als auch hinsichtlich der Gewebespezifität betrachtet. Die Ergebnisse zeigten, dass Keimung zu einer deutlichen Akkumulation von alpha-Dioxygenase mRNA in Erbsen führte. Auch alpha-Dioxygenase Protein war in großer Menge in keimenden und jungen Erbsenpflanzen vorhanden. Ausgeprägte Gewebespezifität war festzustellen: alpha-DOX mRNA fand sich fast ausschließlich in Wurzeln von Erbsenpflanzen, in Sprossgewebe dagegen war sie kaum vorhanden. Im Gegensatz dazu lag alpha-DOX Protein gleichermaßen in Spross- und in Wurzelgewebe vor. Parallel zur Reifung der Pflanzen nahm die Menge an alpha-DOX mRNA und Protein ab. Alpha-Dioxygenase-Aktivität war bereits in trockenen Samen detektierbar, während der Keimung nahm sie deutlich zu. Im Vergleich von Spross- und Wurzelgewebe war die Aktivität in Wurzeln höher, bezogen sowohl auf das Frischgewicht der Pflanzen als auch auf die Menge an Gesamtprotein (spezifische Aktivität). Die Untersuchungen an Wurzeln zeigten, dass die Aktivität bezogen auf das Frischgewicht der Pflanzen über den betrachteten Zeitraum kaum variierte, während die spezifische Aktivität mit zunehmendem Alter der Pflanzen kontinuierlich zunahm. Dieses Ergebnis deutet darauf hin, dass in Erbsen mehrere alpha-Dioxygenase-Isoenzyme vorhanden sind, so wie man dies für andere höhere Pflanzen bereits postuliert hat. Ein zellprotektiver Effekt von alpha-Dioxygenasen auf Pflanzen während der Interaktion mit Pathogenen ist bekannt. Möglicherweise ist dies auch der Grund für eine verstärkte Expression während der Keimung von Pflanzen. Die bevorzugte Expression in Wurzeln könnte auf eine Funktion als permanentes Schutzsystem gegen Infektion hindeuten.
In Staphylococcus aureus, de novo methionine biosynthesis is regulated by a unique hierarchical pathway involving stringent-response controlled CodY repression in combination with a T-box riboswitch and RNA decay. The T-box riboswitch residing in the 5′ untranslated region (met leader RNA) of the S. aureus metICFE-mdh operon controls downstream gene transcription upon interaction with uncharged methionyl-tRNA. met leader and metICFE-mdh (m)RNAs undergo RNase-mediated degradation in a process whose molecular details are poorly understood. Here we determined the secondary structure of the met leader RNA and found the element to harbor, beyond other conserved T-box riboswitch structural features, a terminator helix which is target for RNase III endoribonucleolytic cleavage. As the terminator is a thermodynamically highly stable structure, it also forms posttranscriptionally in met leader/ metICFE-mdh read-through transcripts. Cleavage by RNase III releases the met leader from metICFE-mdh mRNA and initiates RNase J-mediated degradation of the mRNA from the 5′-end. Of note, metICFE-mdh mRNA stability varies over the length of the transcript with a longer lifespan towards the 3′-end. The obtained data suggest that coordinated RNA decay represents another checkpoint in a complex regulatory network that adjusts costly methionine biosynthesis to current metabolic requirements.
The objective was to determine the mRNA expression and protein levels of uPA system components in tissue specimens and serum samples, respectively, from prostate cancer (PCa) patients and to assess their association with clinicopathological parameters and overall survival (OS). The mRNA expression levels of uPA, its receptor (uPAR), and its inhibitor type 1 (PAI-1) were analyzed in corresponding malignant and adjacent nonmalignant tissue specimens from 132 PCa patients by quantitative PCR. Preoperative serum samples from 81 PCa patients were analyzed for antigen levels of uPA system members by ELISA. RNA levels of uPA system components displayed significant correlations with each other in the tumor tissues. A significantly decreased uP AmRNA expression in PCa compared to the corresponding nonmalignant tissue was detected. High uPA mRNA level was significantly associated with a high Gleason score. Elevated concentration of soluble uPAR (suPAR) in serum was significantly associated with a poor OS of PCa patients (P = 0.022). PCa patients with high suPAR levels have a significantly higher risk of death (multivariate Cox's regression analysis; IIR - 7.12, P - 0.027). The association of high suPAR levels with poor survival of PCa patients suggests a prognostic impact of suPAR levels in serum of cancer patients.
Bioactive glass (BG) scaffolds are being investigated for bone tissue engineering applications because of their osteoconductive and angiogenic nature. However, to increase the in vivo performance of the scaffold, including enhancing the angiogenetic growth into the scaffolds, some researchers use different modifications of the scaffold including addition of inorganic ionic components to the basic BG composition. In this study, we investigated the in vitro biocompatibility and bioactivity of Cu2+-doped BG derived scaffolds in either BMSC (bone-marrow derived mesenchymal stem cells)-only culture or co-culture of BMSC and human dermal microvascular endothelial cells (HDMEC). In BMSC-only culture, cells were seeded either directly on the scaffolds (3D or direct culture) or were exposed to ionic dissolution products of the BG scaffolds, kept in permeable cell culture inserts (2D or indirect culture). Though we did not observe any direct osteoinduction of BMSCs by alkaline phosphatase (ALP) assay or by PCR, there was increased vascular endothelial growth factor (VEGF) expression, observed by PCR and ELISA assays. Additionally, the scaffolds showed no toxicity to BMSCs and there were healthy live cells found throughout the scaffold. To analyze further the reasons behind the increased VEGF expression and to exploit the benefits of the finding, we used the indirect method with HDMECs in culture plastic and Cu2+-doped BG scaffolds with or without BMSCs in cell culture inserts. There was clear observation of increased endothelial markers by both FACS analysis and acetylated LDL (acLDL) uptake assay. Only in presence of Cu2+-doped BG scaffolds with BMSCs, a high VEGF secretion was demonstrated by ELISA; and typical tubular structures were observed in culture plastics. We conclude that Cu2+-doped BG scaffolds release Cu2+, which in turn act on BMSCs to secrete VEGF. This result is of significance for the application of BG scaffolds in bone tissue engineering approaches.
Introduction
We characterized dermal innervation in patients with fibromyalgia syndrome (FMS) as potential contribution to small fiber pathology.
Methods
Skin biopsies of the calf were collected (86 FMS patients, 35 healthy controls). Skin was immunoreacted with antibodies against protein gene product 9.5, calcitonine gene-related peptide, substance P, CD31, and neurofilament 200 for small fiber subtypes. We assessed two skin sections per patient; on each skin section, two dermal areas (150 x 700 mu m each) were investigated for dermal nerve fiber length (DNFL).
Results
In FMS patients we found reduced DNFL of fibers with vessel contact compared to healthy controls (p<0.05). There were no differences for the other nerve fiber subtypes.
Discussion
We found less dermal nerve fibers in contact with blood vessels in FMS patients than in controls. The pathophysiological relevance of this finding is unclear, but we suggest the possibility of a relationship with impaired thermal tolerance commonly reported by FMS patients.