Publications by authors named "Sandor Nietzsche"

80 Publications

In Vitro Activity of Propolis on Oral Microorganisms and Biofilms.

Antibiotics (Basel) 2021 Aug 26;10(9). Epub 2021 Aug 26.

Department of Periodontology, School of Dental Medicine, University of Bern, 3010 Bern, Switzerland.

Natural products are being discussed as alternatives to commonly used chemicals in antimicrobial therapy. The study aimed to investigate the antimicrobial activity of propolis against microbial species associated with caries, periodontal disease, and Candida infections. Two commercially available ethanolic extracts of Brazilian and one of European propolis (EEP) were used. The minimal inhibitory concentrations (MIC) of propolis and controls against eight microbial strains were determined. Scanning and transmission electron microscopy (SEM and TEM) images visualized the effect of propolis on microorganisms. Subsequently, the activity on three different multi-species biofilms (both formation and existing biofilms) was assessed. All MIC values of the Brazilian EEPs were low against the tested oral species (≤0.1 mg/mL-3.13 mg/mL propolis ()). The European EEP had slightly higher MICs than the Brazilian EEPs. The SEM and TEM images suggest an interaction of propolis with the microbial cell wall. The European EEP exhibited the strongest effect on retarding biofilm formation, whereas the Brazilian EEPs were highly active against preformed biofilms (100 mg/mL propolis of both EEPs reduced colony forming unit counts always by more than 6 log10). The antimicrobial and anti-biofilm activities point to the potential of propolis as an adjunct in oral health care products.
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http://dx.doi.org/10.3390/antibiotics10091045DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8472590PMC
August 2021

Intracellular persistence of in endothelial cells is promoted by the absence of phenol-soluble modulins.

Virulence 2021 12;12(1):1186-1198

Institute of Medical Microbiology, Jena University Hospital, Jena, Germany.

A large proportion of clinical isolates that carry an inactive Agr system are associated with persistent infection that is difficult to treat. Once is inside the bloodstream, it can cross the endothelial barrier and invade almost every organ in the human body. Endothelial cells can either be lysed by this pathogen or they serve as a niche for its intracellular long-term survival. Following phagocytosis, several vesicles such as phagosomes and autophagosomes, target intracellular for elimination. can escape from these vesicles into the host cytoplasm through the activation of phenol-soluble modulins (PSMs) αβ. Thereafter, it replicates and lyses the host cell to disseminate to adjacent tissues. Herein we demonstrate that staphylococcal strains which lack the expression of PSMs employ an alternative pathway to better persist within endothelial cells. The intracellular survival of is associated with the co-localization of the autophagy marker LC3. In cell culture infection models, we found that the absence of decreased the host cell lysis and increased staphylococcal long-term survival. This study explains the positive selection of -negative strains that lack the expression of in chronic infection due to their advantage in surviving and evading the clearance system of the host.
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http://dx.doi.org/10.1080/21505594.2021.1910455DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8043190PMC
December 2021

Early postmortem mapping of SARS-CoV-2 RNA in patients with COVID-19 and the correlation with tissue damage.

Elife 2021 03 30;10. Epub 2021 Mar 30.

Institute of Forensic Medicine, Jena University Hospital, Jena, Germany.

Clinical observations indicate that COVID-19 is a systemic disease. An investigation of the viral distribution within the human body and its correlation with tissue damage can aid in understanding the pathophysiology of SARS-CoV-2 infection. We present a detailed mapping of the viral RNA in 61 tissues and organs of 11 deceased patients with COVID-19. The autopsies were performed within the early postmortem interval (between 1.5 and 15 hr, mean: 5.6 hr) to minimize the bias due to viral RNA and tissue degradation. Very high viral loads (>10copies/ml) were detected in most patients' lungs, and the presence of intact viral particles in the lung tissue could be verified by transmission electron microscopy. Interestingly, viral RNA was detected throughout various extrapulmonary tissues and organs without visible tissue damage. The dissemination of SARS-CoV-2-RNA throughout the body supports the hypothesis that there is a maladaptive host response with viremia and multiorgan dysfunction.
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http://dx.doi.org/10.7554/eLife.60361DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8009677PMC
March 2021

SARS-CoV-2 causes severe epithelial inflammation and barrier dysfunction.

J Virol 2021 Feb 26. Epub 2021 Feb 26.

Section of Experimental Virology, Institute of Medical Microbiology, Jena University Hospital, Hans-Knoell-Str. 2, D-07745, Jena, Germany

Infections with SARS-CoV-2 can be asymptomatic, but they can also be accompanied by a variety of symptoms that result in mild to severe coronavirus disease-19 (COVID-19) and are sometimes associated with systemic symptoms. Although the viral infection originates in the respiratory system, it is unclear how the virus can overcome the alveolar barrier, which is observed in severe COVID-19 disease courses. To elucidate the viral effects on the barrier integrity and immune reactions, we used mono-cell culture systems and a complex human chip model composed of epithelial, endothelial, and mononuclear cells. Our data show that SARS-CoV-2 efficiently infected epithelial cells with high viral loads and inflammatory response, including interferon expression. By contrast, the adjacent endothelial layer was neither infected nor did it show productive virus replication or interferon release. With prolonged infection, both cell types were damaged, and the barrier function was deteriorated, allowing the viral particles to overbear. In our study, we demonstrate that although SARS-CoV-2 is dependent on the epithelium for efficient replication, the neighboring endothelial cells are affected, e.g., by the epithelial cytokines or components induced during infection, which further results in the damage of the epithelial/endothelial barrier function and viral dissemination.SARS-CoV-2 challenges healthcare systems and societies worldwide in unprecedented ways. Although numerous new studies have been conducted, research to better understand the molecular pathogen-host interactions are urgently needed. For this, experimental models have to be developed and adapted. In the present study we used mono cell-culture systems and we established a complex chip model, where epithelial and endothelial cells are cultured in close proximity. We demonstrate that epithelial cells can be infected with SARS-CoV-2, while the endothelium did not show any infection signs. Since SARS-CoV-2 is able to establish viremia, the link to thromboembolic events in severe COVID-19 courses is evident. However, whether the endothelial layer is damaged by the viral pathogens or whether other endothelial-independent homeostatic factors are induced by the virus is essential for understanding the disease development. Therefore, our study is important as it demonstrates that the endothelial layer could not be infected by SARS-CoV-2 in our experiments, but we were able to show the destruction of the epithelial-endothelial barrier in our chip model. From our experiments we can assume that virus-induced host factors disturbed the epithelial-endothelial barrier function and thereby promote viral spread.
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http://dx.doi.org/10.1128/JVI.00110-21DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8139673PMC
February 2021

The impact of episporic modification of on virulence and interaction with phagocytes.

Comput Struct Biotechnol J 2021 20;19:880-896. Epub 2021 Jan 20.

Leibniz Institute for Natural Product Research and Infection Biology - Hans Knöll Institute (HKI), Jena, Germany.

Fungal infections caused by the ancient lineage Mucorales are emerging and increasingly reported in humans. Comprehensive surveys on promising attributes from a multitude of possible virulence factors are limited and so far, focused on and . This study addresses a systematic approach to monitor phagocytosis after physical and enzymatic modification of the outer spore wall of , one of the major causative agents of mucormycosis. Episporic modifications were performed and their consequences on phagocytosis, intracellular survival and virulence by murine alveolar macrophages and in an invertebrate infection model were elucidated. While depletion of lipids did not affect the phagocytosis of both strains, delipidation led to attenuation of LCA strain but appears to be dispensable for infection with LCV strain in the settings used in this study. Combined glucano-proteolytic treatment was necessary to achieve a significant decrease of virulence of the LCV strain in during maintenance of the full potential for spore germination as shown by a novel automated germination assay. Proteolytic and glucanolytic treatments largely increased phagocytosis compared to alive resting and swollen spores. Whilst resting spores barely (1-2%) fuse to lysosomes after invagination in to phagosomes, spore trypsinization led to a 10-fold increase of phagolysosomal fusion as measured by intracellular acidification. This is the first report of a polyphasic measurement of the consequences of episporic modification of a mucormycotic pathogen in spore germination, spore surface ultrastructure, phagocytosis, stimulation of Toll-like receptors (TLRs), phagolysosomal fusion and intracellular acidification, apoptosis, generation of reactive oxygen species (ROS) and virulence.
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http://dx.doi.org/10.1016/j.csbj.2021.01.023DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7851798PMC
January 2021

In vitro Activity of Oral Health Care Products on Candida Biofilm Formation.

Monogr Oral Sci 2021 21;29:214-226. Epub 2020 Dec 21.

Department of Periodontology, School of Dental Medicine, University of Bern, Bern, Switzerland,

The activity of mouthwash ingredients used in daily oral care (chlorhexidine digluconate, benzalkonium chloride, povidone iodine solution, tea tree oil) and of nystatin was evaluated not only on planktonic Candida albicans or C. glabrata, but also on the inhibition of biofilm formation. A microbroth dilution technique was used to determine the minimum inhibitory concentration of the substances against two laboratory strains and seven clinical isolates. Furthermore, a potential inhibition of biofilm formation of C. albicans or C. glabrata (single-species biofilm or mixed with two oral bacteria) was assessed. The results showed an activity of all tested substances against all C. albicans and C. glabratastrains. In the biofilm assays, a concentration-dependent effect of the substances was visible. However, a low concentration of povidone iodine solution and in particular of benzalkonium chloride seemed to increase the virulence of C. albicans. Most test substances affected both bacteria and yeasts in the mixed biofilms, only nystatin predominately reduced the yeasts. In conclusion, nystatin might be the drug of choice when exclusively preventing the colonization of Candida sp. in biofilms. The alternatives, benzalkonium chloride, povidone iodine solution, and tea tree oil, should be investigated further.
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http://dx.doi.org/10.1159/000510194DOI Listing
January 2021

Biotech nanocellulose: A review on progress in product design and today's state of technical and medical applications.

Carbohydr Polym 2021 Feb 30;254:117313. Epub 2020 Oct 30.

Department of Pharmaceutical Technology and Biopharmacy, Friedrich-Schiller-University Jena, Lessingstrasse 8, 07743 Jena, Germany. Electronic address:

Biotech nanocellulose (bacterial nanocellulose, BNC) is a high potential natural polymer. Moreover, it is the only cellulose type that can be produced biotechnologically using microorganisms resulting in hydrogels with high purity, high mechanical strength and an interconnecting micropore system. Recently, the subject of intensive research is to influence this biosynthesis to create function-determining properties. This review reports on the progress in product design and today's state of technical and medical applications. A novel, dynamic, template-based technology, called Mobile Matrix Reservoir Technology (MMR Tech), is highlighted. Thereby, shape, dimensions, surface properties, and nanonetwork structures can be designed in a process-controlled manner. The formed multilayer materials open up new applications in medicine and technology. Especially medical materials for cardiovascular and visceral surgery, and drug delivery systems are developed. The effective production of layer-structured composites and coatings are important for potential applications in the electronics, paper, food and packaging technologies.
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http://dx.doi.org/10.1016/j.carbpol.2020.117313DOI Listing
February 2021

Skeletal Muscle Function, Structure, and Metabolism in Patients With Heart Failure With Reduced Ejection Fraction and Heart Failure With Preserved Ejection Fraction.

Circ Heart Fail 2020 12 11;13(12):e007198. Epub 2020 Dec 11.

Division of Cardiology, Pneumology, and Intensive Medical Care, Department of Internal Medicine I (M.B.E., A.H., E.F., J.W., D.H., T.K., S.M.-W., P.C.S.), Friedrich-Schiller-University, Germany.

Background: Reduced exercise capacity in patients with heart failure (HF) could be partially explained by skeletal muscle dysfunction. We compared skeletal muscle function, structure, and metabolism among clinically stable outpatients with HF with preserved ejection fraction, HF with reduced ejection fraction, and healthy controls (HC). Furthermore, the molecular, metabolic, and clinical profile of patients with reduced muscle endurance was described.

Methods: Fifty-five participants were recruited prospectively at the University Hospital Jena (17 HF with preserved ejection fraction, 18 HF with reduced ejection fraction, and 20 HC). All participants underwent echocardiography, cardiopulmonary exercise testing, 6-minute walking test, isokinetic muscle function, and skeletal muscle biopsies. Expression levels of fatty acid oxidation, glucose metabolism, atrophy genes, and proteins as well as inflammatory biomarkers were assessed. Mitochondria were evaluated using electron microscopy.

Results: Patients with HF with preserved ejection fraction showed compared with HF with reduced ejection fraction and HC reduced muscle strength (eccentric extension: 13.3±5.0 versus 18.0±5.9 versus 17.9±5.1 Nm/kg, =0.04), elevated levels of MSTN-2 (myostatin-2), FBXO-32 (F-box only protein 32 [Atrogin1]) gene and protein, and smaller mitochondrial size (<0.05). Mitochondrial function and fatty acid and glucose metabolism were impaired in HF-patients compared with HC (<0.05). In a multiple regression analysis, GDF-15 (growth and differentiation factor 15), CPT1B (carnitine palmitoyltransferase IB)-protein and oral anticoagulation were independent factors for predicting reduced muscle endurance after adjusting for age (log10 GDF-15 [pg/mL] [B, -54.3 (95% CI, -106 to -2.00), =0.043], log10 CPT1B per fold increase [B, 49.3 (95% CI, 1.90-96.77), =0.042]; oral anticoagulation present [B, 44.8 (95% CI, 27.90-61.78), <0.001]).

Conclusions: Patients with HF with preserved ejection fraction have worse muscle function and predominant muscle atrophy compared with those with HF with reduced ejection fraction and HC. Inflammatory biomarkers, fatty acid oxidation, and oral anticoagulation were independent factors for predicting reduced muscle endurance.
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http://dx.doi.org/10.1161/CIRCHEARTFAILURE.120.007198DOI Listing
December 2020

Effect of scaling on the invasion of oral microorganisms into dentinal tubules including the response of pulpal cells-an in vitro study.

Clin Oral Investig 2021 Feb 4;25(2):769-777. Epub 2020 Dec 4.

Department of Periodontology, School of Dental Medicine, University of Bern, Freiburgstrasse 7, 3010, Bern, Switzerland.

Objectives: To investigate how scaling affects the penetration of microorganisms into dentinal tubules, how pulpal cells seeded into the pulp cavity respond to bacterial challenge, and how penetration and inflammatory response may depend on the bacterial composition.

Materials And Methods: Root canals of 102 extracted human teeth underwent shaping and cleaning. Half of the teeth were subjected to scaling and root planing, the other half remained untreated. Teeth were exposed to either Streptococcus gordonii and Actinomyces oris or S. gordonii and Porphyromonas gingivalis for 10 weeks. Bacterial invasion was assessed in a depth of 1 mm to the root surface. Human pulpal cells were seeded into the cavities to assess the expression of interleukin-8 (IL-8), monocyte chemoattractant protein-1 (MCP-1), and matrix metalloproteinase-3 (MMP-3) by real-time polymerase chain reaction and immunoassay.

Results: The percentage of teeth with bacteria detected in dentine was higher when teeth received scaling than when they were untreated: 66.6% versus 44.4% when exposed to A. oris/S. gordonii, and 50% versus 25% when exposed to P. gingivalis/S. gordonii (p = 0.043). Scaling had no impact on IL-8 and MMP-3 expression in pulpal cells. P. gingivalis/S. gordonii caused higher levels of IL-8, MCP-1, and MMP-3 than A. oris/S. gordonii (p = 0.003, p = 0.011, p = 0.037).

Conclusion: Scaling supports the penetration of bacteria into the dentine of extracted human teeth. P. gingivalis may affect the immune response in pulpal cells.

Clinical Relevance: Root surface debridement with hand instruments may facilitate bacterial penetration. Other kinds of mechanical instrumentation in this experimental setting should be investigated.
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http://dx.doi.org/10.1007/s00784-020-03705-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7820079PMC
February 2021

In vitro hemo- and cytocompatibility of bacterial nanocelluose small diameter vascular grafts: Impact of fabrication and surface characteristics.

PLoS One 2020 24;15(6):e0235168. Epub 2020 Jun 24.

Department of Cardiothoracic Surgery, University Hospital of Magdeburg, Magdeburg, Germany.

Objective: There is an increasing need for small diameter vascular grafts with superior host hemo- and cytocompatibilities, such as low activation of platelets and leukocytes. Therefore, we aimed to investigate whether the preparation of bacterial nanocellulose grafts with different inner surfaces has an impact on in vitro host cytocompatibility.

Methods: We have synthesized five different grafts in a bioreactor, namely open interface surface (OIS), inverted (INV), partially air dried (PAD), surface formed in air contact (SAC) and standard (STD) that were characterized by a different surface roughness. The grafts (length 55 mm, inner diameter 5 mm) were attached to heparinized polyvinyl chloride tubes, loaded with human blood and rotated at 37°C for 4 hours. Then, blood was analyzed for frequencies of cellular fractions, oxidative products, soluble complement and thrombin factors. The results were compared to clinically approved grafts made of polyethylene terephthalate and expanded polytetrafluoroethylene. Additionally, blood platelets were labelled with 111Indium-oxine to visualize the distribution of adherent platelets in the loop by scintigraphy.

Results: SAC nanocellulose grafts with the lowest surface roughness exhibited superior performance with <10% leukocyte and <50% thrombocyte loss in contrast to other grafts that exhibited >65% leukocyte and >90% thrombocyte loss. Of note, SAC nanocellulose grafts showed lowest radioactivity with scintigraphy analyses, indicating reduced platelet adhesion. Although the levels of reactive oxygen species and cell free DNA did not differ significantly, the levels of thrombin-antithrombin complexes were lowest in SAC grafts. However, all nanocellulose grafts exhibited enhanced complement activation.

Conclusion: The systematic variation of the inner surfaces of BNC vascular grafts significantly improves biocompatibility. Especially, SAC grafts exhibited the lowest loss of platelets as well as leukocytes and additionally significantly diminished activation of the coagulation system. Further animal studies are needed to study in vivo biocompatibilities.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0235168PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7313737PMC
September 2020

Novel morphological multi-scale evaluation system for quality assessment of decellularized liver scaffolds.

J Tissue Eng 2020 Jan-Dec;11:2041731420921121. Epub 2020 May 27.

Experimental Transplantation Surgery, Department of General, Visceral and Vascular Surgery, University Hospital Jena, Jena, Germany.

Decellularized scaffolds can serve as an excellent three-dimensional environment for cell repopulation. They maintain tissue-specific microarchitecture of extracellular matrix proteins with important spatial cues for cell adhesion, migration, growth, and differentiation. However, criteria for quality assessment of the three-dimensional structure of decellularized scaffolds are rather fragmented, usually study-specific, and mostly semi-quantitative. Thus, we aimed to develop a robust structural assessment system for decellularized porcine liver scaffolds. Five scaffolds of different quality were used to establish the new evaluation system. We combined conventional semi-quantitative scoring criteria with a quantitative scaffold evaluation based on automated image analysis. For the quantitation, we developed a specific open source software tool (ScaffAn) applying algorithms designed for texture analysis, segmentation, and skeletonization. ScaffAn calculates selected parameters characterizing structural features of porcine liver scaffolds such as the sinusoidal network. After evaluating individual scaffolds, the total scores predicted scaffold interaction with cells in terms of cell adhesion. Higher scores corresponded to higher numbers of cells attached to the scaffolds. Moreover, our analysis revealed that the conventional system could not identify fine differences between good quality scaffolds while the additional use of ScaffAn allowed discrimination. This led us to the conclusion that only using the combined score resulted in the best discrimination between different quality scaffolds. Overall, our newly defined evaluation system has the potential to select the liver scaffolds most suitable for recellularization, and can represent a step toward better success in liver tissue engineering.
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http://dx.doi.org/10.1177/2041731420921121DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7257850PMC
May 2020

Longitudinal metabolic profiling of cardiomyocytes derived from human-induced pluripotent stem cells.

Basic Res Cardiol 2020 05 18;115(4):37. Epub 2020 May 18.

Department of Internal Medicine I, Division of Cardiology, University Hospital Jena, FSU, FZL Haus F4, Am Klinikum 1, 07747, Jena, Germany.

Human-induced pluripotent stem cells (h-iPSCs) are a unique in vitro model for cardiovascular research. To realize the potential applications of h-iPSCs-derived cardiomyocytes (CMs) for drug testing or regenerative medicine and disease modeling, characterization of the metabolic features is critical. Here, we show the transcriptional profile during stages of cardiomyogenesis of h-iPSCs-derived CMs. CM differentiation was not only characterized by the expression of mature structural components (MLC2v, MYH7) but also accompanied by a significant increase in mature metabolic gene expression and activity. Our data revealed a distinct substrate switch from glucose to fatty acids utilization for ATP production. Basal respiration and respiratory capacity in 9 days h-iPSCs-derived CMs were glycolysis-dependent with a shift towards a more oxidative metabolic phenotype at 14 and 28 day old CMs. Furthermore, mitochondrial analysis characterized the early and mature forms of mitochondria during cardiomyogenesis. These results suggest that changes in cellular metabolic phenotype are accompanied by increased O consumption and ATP synthesis to fulfill the metabolic needs of mature CMs activity. To further determine functionality, the physiological response of h-iPSCs-derived CMs to β-adrenergic stimulation was tested. These data provide a unique in vitro human heart model for the understanding of CM physiology and metabolic function which may provide useful insight into metabolic diseases as well as novel therapeutic options.
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http://dx.doi.org/10.1007/s00395-020-0796-0DOI Listing
May 2020

Lung Infection Results in Down-Regulation of Surfactant Protein-A Mainly Caused by Pro-Inflammatory Macrophages.

Microorganisms 2020 Apr 16;8(4). Epub 2020 Apr 16.

Institute of Medical Microbiology, Jena University Hospital, Am Klinikum1, D-07747 Jena, Germany.

Pneumonia is the leading cause of hospitalization worldwide. Besides viruses, bacterial co-infections dramatically exacerbate infection. In general, surfactant protein-A (SP-A) represents a first line of immune defense. In this study, we analyzed whether influenza A virus (IAV) and/or () infections affect SP-A expression. To closely reflect the situation in the lung, we used a human alveolus-on-a-chip model and a murine pneumonia model. Our results show that can reduce extracellular levels of SP-A, most likely attributed to bacterial proteases. Mono-epithelial cell culture experiments reveal that the expression of SP-A is not directly affected by IAV or . Yet, the mRNA expression of SP-A is strongly down-regulated by TNF-α, which is highly produced by professional phagocytes in response to bacterial infection. By using the human alveolus-on-a-chip model, we show that the down-regulation of SP-A is strongly dependent on macrophages. In a murine model of pneumonia, we can confirm that decreases SP-A levels in vivo. These findings indicate that (I) complex interactions of epithelial and immune cells induce down-regulation of SP-A expression and (II) bacterial mono- and super-infections reduce SP-A expression in the lung, which might contribute to a severe outcome of bacterial pneumonia.
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http://dx.doi.org/10.3390/microorganisms8040577DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7232181PMC
April 2020

Human Neutrophils Produce Antifungal Extracellular Vesicles against Aspergillus fumigatus.

mBio 2020 04 14;11(2). Epub 2020 Apr 14.

Institute of Microbiology, Friedrich Schiller University, Jena, Germany

Polymorphonuclear granulocytes (PMNs) are indispensable for controlling life-threatening fungal infections. In addition to various effector mechanisms, PMNs also produce extracellular vesicles (EVs). Their contribution to antifungal defense has remained unexplored. We reveal that the clinically important human-pathogenic fungus triggers PMNs to release a distinct set of antifungal EVs (afEVs). Proteome analyses indicated that afEVs are enriched in antimicrobial proteins. The cargo and the release kinetics of EVs are modulated by the fungal strain confronted. Tracking of afEVs indicated that they associated with fungal cells and even entered fungal hyphae, resulting in alterations in the morphology of the fungal cell wall and dose-dependent antifungal effects. To assess as a proof of concept whether the antimicrobial proteins found in afEVs might contribute to growth inhibition of hyphae when present in the fungal cytoplasm, two human proteins enriched in afEVs, cathepsin G and azurocidin, were heterologously expressed in fungal hyphae. This led to reduced fungal growth relative to that of a control strain producing the human retinol binding protein 7. In conclusion, extracellular vesicles produced by neutrophils in response to infection are able to associate with the fungus, limit growth, and elicit cell damage by delivering antifungal cargo. This finding offers an intriguing, previously overlooked mechanism of antifungal defense against Invasive fungal infections caused by the mold are a growing concern in the clinic due to the increasing use of immunosuppressive therapies and increasing antifungal drug resistance. These infections result in high rates of mortality, as treatment and diagnostic options remain limited. In healthy individuals, neutrophilic granulocytes are critical for elimination of from the host; however, the exact extracellular mechanism of neutrophil-mediated antifungal activity remains unresolved. Here, we present a mode of antifungal defense employed by human neutrophils against not previously described. We found that extracellular vesicles produced by neutrophils in response to infection are able to associate with the fungus, limit growth, and elicit cell damage by delivering antifungal cargo. In the end, antifungal extracellular vesicle biology provides a significant step forward in our understanding of host pathogenesis and opens up novel diagnostic and therapeutic possibilities.
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http://dx.doi.org/10.1128/mBio.00596-20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7157820PMC
April 2020

Taurolidine Acts on Bacterial Virulence Factors and Does Not Induce Resistance in Periodontitis-Associated Bacteria-An In-Vitro Study.

Antibiotics (Basel) 2020 Apr 7;9(4). Epub 2020 Apr 7.

Department of Periodontology, School of Dental Medicine, University of Bern, CH-3010 Bern, Switzerland.

The aims of the present study were: (a) to determine the mechanism of action of taurolidine against bacterial species associated with periodontal disease, and (b) to evaluate the potential development of resistance against taurolidine as compared with minocycline. After visualizing the mode of action of taurolidine by transmission electron micrographs, the interaction with most important virulence factors (lipopolysaccharide (LPS), gingipains, leukotoxin), was analyzed. Then, 14 clinical isolates from subgingival biofilm samples were transferred on agar plates containing subinhibitory concentrations of taurolidine or minocycline up to 50 passages. Before and after each 10 passages, minimal inhibitory concentrations (MICs) were determined. Increasing MICs were screened for efflux mechanism. Taurolidine inhibited in a concentration-dependent manner the activities of LPS and of the arginine-specific gingipains; however, an effect on leukotoxin was not detected. One strain developed a resistance against taurolidine, which was probably linked with efflux . An increase of MIC values of minocycline occurred in five of the 14 included strains after exposure to subinhibitory concentrations of the antibiotic. The present results indicate that: a) taurolidine interacts with LPS and gingipains, and b) development of resistance seems to be a rare event when using taurolidine.
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http://dx.doi.org/10.3390/antibiotics9040166DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7235838PMC
April 2020

Regulation of Cyclooxygenase 2 by in Fibroblastic and Monocytic Cells.

Mediators Inflamm 2020 3;2020:4185273. Epub 2020 Feb 3.

Department of Periodontology and Operative Dentistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany.

Periodontitis is a prevalent chronic inflammatory disease triggered by a synergistic and dysbiotic microbiota present in the oral biofilm. This in vitro study is aimed at evaluating the regulation of cyclooxygenase (COX)2 expression and production by the periodontopathogen in human gingival fibroblastic (HGF-1) and monocytic (THP-1) cells and also at investigating the underlying cellular pathway mechanisms. HGF-1 and THP-1 cells were exposed either to or to the proinflammatory cytokine tumor necrosis factor alpha (TNF) for 1 and 2 d to examine the COX2 expression by qPCR. COX2 protein levels were evaluated by ELISA in -stimulated cells. Both types of cells were also stimulated with a blocking toll-like receptor (TLR)2 antibody or specific inhibitors against MAPKs. significantly ( < 0.05) increased COX2 at both transcriptional and protein levels in both HGF-1 and THP-1 cells. Moreover, the stimulatory effect of on COX2 was more pronounced in HGF-1 cells in comparison to THP-1 cells. upregulated the COX2 expression in a dose-dependent manner in both type cells at 1 d. TNF also significantly ( < 0.05) increased the COX2 expression in both cells. After preincubation of HGF-1 and THP-1 cells either with a neutralizing anti-TLR2 antibody or with specific MAPK inhibitors, the -upregulated COX2 expression was significantly ( < 0.05) suppressed at 1 d. Our in vitro study provides original evidence that stimulates COX2 production in fibroblastic and monocytic cells through TLR2 and MAPK mechanisms, suggesting a role of this periodontopathogen in the etiopathogenesis of periodontitis.
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http://dx.doi.org/10.1155/2020/4185273DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7023199PMC
November 2020

Co-infection with Staphylococcus aureus after primary influenza virus infection leads to damage of the endothelium in a human alveolus-on-a-chip model.

Biofabrication 2020 02 19;12(2):025012. Epub 2020 Feb 19.

Institute of Medical Microbiology, Jena University Hospital, Am Klinikum 1, D-07747 Jena, Germany. Center for Sepsis Control and Care, Jena University Hospital, D-07747 Jena, Germany. Section of Experimental Virology, Institute of Medical Microbiology, Jena University Hospital, Hans-Knöll-Str. 2, D-07745, Jena, Germany.

Pneumonia is one of the most common infectious diseases worldwide. The influenza virus can cause severe epidemics, which results in significant morbidity and mortality. Beyond the virulence of the virus itself, epidemiological data suggest that bacterial co-infections are the major cause of increased mortality. In this context, Staphylococcus aureus represents a frequent causative bacterial pathogen. Currently available models have several limitations in the analysis of the pathogenesis of infections, e.g. some bacterial toxins strongly act in a species-specific manner. Human 2D mono-cell culture models often fail to maintain the differentiation of alveolus-specific functions. A detailed investigation of the underlying pathogenesis mechanisms requires a physiological interaction of alveolus-specific cell types. The aim of the present work was to establish a human in vitro alveolus model system composed of vascular and epithelial cell structures with cocultured macrophages resembling the human alveolus architecture and functions. We demonstrate that high barrier integrity maintained for up to 14 d in our model containing functional tissue-resident macrophages. We show that flow conditions and the presence of macrophages increased the barrier function. The infection of epithelial cells induced a high inflammatory response that spread to the endothelium. Although the integrity of the epithelium was not compromised by a single infection or co-infection, we demonstrated significant endothelial cell damage associated with loss of barrier function. We established a novel immune-responsive model that reflects the complex crosstalk between pathogens and host. The in vitro model allows for the monitoring of spatiotemporal spreading of the pathogens and the characterization of morphological and functional alterations attributed to infection. The alveolus-on-a-chip represents a promising platform for mechanistic studies of host-pathogen interactions and the identification of molecular and cellular targets of novel treatment strategies in pneumonia.
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http://dx.doi.org/10.1088/1758-5090/ab7073DOI Listing
February 2020

A Survival Model of Partial Liver Lobe Decellularization Towards Liver Engineering.

Tissue Eng Part C Methods 2020 08 26;26(8):402-417. Epub 2019 Dec 26.

Experimental Transplantation Surgery, Department of General, Visceral and Vascular Surgery, Jena University Hospital, Jena, Germany.

liver decellularization has become a promising strategy to study liver engineering. However, long-term survival after liver decellularization has not yet been achieved due to anatomical and technical challenges. This study aimed at establishing a survival model of partial liver lobe perfusion-decellularization in rats. We compared three decellularization protocols (1% Triton X100 followed by 1% sodium dodecyl sulfate [SDS], 1% SDS vs. 1% Triton X100,  = 6/group). Using the optimal one as judged by macroscopy, histology and DNA content, we characterized the structural integrity and matrix proteins by using histology, scanning electron microscopy, computed tomography scanning, and immunohistochemistry (IHC). We prevented contamination of the abdominal cavity with the corrosive detergents by using polyvinylidene chloride (PVDC) film + dry gauze in comparison to PVDC film + dry gauze + aspiration tube ( = 6/group). Physiological reperfusion was assessed by histology. Survival rate was determined after a 7-day observation period. Only perfusion with 1% SDS resulted in an acellular scaffold (fully translucent without histologically detectable tissue remnants, DNA concentration is <2% of that in native lobe) with remarkable structural and ultrastructural integrity as well as preservation of main matrix proteins (IHC positive for collagen IV, laminin, and elastin). Contamination of abdominal organs with the potentially toxic SDS solution was achieved by placing a suction tube in addition to the PVDC film + dry gauze and allowed a 7-day survival of all animals without severe postoperative complications. On reperfusion, the liver turned red within seconds without any leakage from the surface of the liver. About 12 h after reperfusion, not only blood cells but also some clots were visible in the portal vein, sinusoidal matrix network, and central vein, suggesting physiological perfusion. In conclusion, our results of this study show the first available data on generation of a survival model of parenchymal organ decellularization, creating a critical step toward organ engineering. Impact Statement Recently, liver decellularization has been considered a promising approach to study liver repopulation of a scaffold compared with liver repopulation. However, long-term survival of liver decellularization has not yet been achieved. Here, despite anatomical and technical challenges, we successfully created a survival model of selected liver lobe decellularization in rats, providing a major step toward organ engineering.
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http://dx.doi.org/10.1089/ten.TEC.2019.0194DOI Listing
August 2020

A three-dimensional immunocompetent intestine-on-chip model as in vitro platform for functional and microbial interaction studies.

Biomaterials 2019 11 2;220:119396. Epub 2019 Aug 2.

Center for Sepsis Control and Care, Jena University Hospital, Friedrich-Schiller-University of Jena, Jena, Germany; Institute of Biochemistry II, Jena University Hospital, Jena, Germany. Electronic address:

Alterations of the microbial composition in the gut and the concomitant dysregulation of the mucosal immune response are associated with the pathogenesis of opportunistic infections, chronic inflammation, and inflammatory bowel disease. To create a platform for the investigation of the underlying mechanisms, we established a three-dimensional microphysiological model of the human intestine. This model resembles organotypic microanatomical structures and includes tissue resident innate immune cells exhibiting features of mucosal macrophages and dendritic cells. The model displays the physiological immune tolerance of the intestinal lumen to microbial-associated molecular patterns and can, therefore, be colonised with living microorganisms. Functional studies on microbial interaction between probiotic Lactobacillus rhamnosus and the opportunistic pathogen Candida albicans show that pre-colonization of the intestinal lumen of the model by L. rhamnosus reduces C. albicans-induced tissue damage, lowers its translocation, and limits fungal burden. We demonstrate that microbial interactions can be efficiently investigated using the in vitro model creating a more physiological and immunocompetent microenvironment. The intestinal model allows a detailed characterisation of the immune response, microbial pathogenicity mechanisms, and quantification of cellular dysfunction attributed to alterations in the microbial composition.
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http://dx.doi.org/10.1016/j.biomaterials.2019.119396DOI Listing
November 2019

Effect of biomimetic mineralization on enamel and dentin: A Raman and EDX analysis.

Dent Mater 2019 09 14;35(9):1300-1307. Epub 2019 Jun 14.

Clinic of Conservative Dentistry and Periodontology, Center of Dental Medicine, Jena University Hospital, Friedrich-Schiller University Jena, Germany.

Objective: To investigate the effect of an experimental biomimetic mineralization kit (BIMIN) on the chemical composition and crystallinity of caries-free enamel and dentin samples in vitro.

Methods: Enamel and dentin samples from 20 human teeth (10 for enamel; 10 for dentin) were divided into a control group without treatment and test samples with BIMIN treatment. Quantitative analysis of tissue penetration of fluoride, phosphate, and calcium was performed using energy-dispersive X-ray spectroscopy (EDX). Mineralization depth was measured by Raman spectroscopy probing the symmetric valence vibration near 960cm as a marker for crystallinity. EDX data was statistically analyzed using a paired t-test and Raman data was analyzed using the Student's t-test.

Results: EDX analysis demonstrated a penetration depth of fluoride of 4.10±3.32μm in enamel and 4.31±2.67μm in dentin. Calcium infiltrated into enamel 2.65±0.64μm and into dentin 5.58±1.63μm, while the penetration depths for phosphate were 4.83±2.81μm for enamel and 6.75±3.25μm for dentin. Further, up to 25μm of a newly mineralized enamel-like layer was observed on the surface of the samples. Raman concentration curves demonstrated an increased degree of mineralization up to 5-10μm into the dentin and enamel samples.

Significance: Biomimetic mineralization of enamel and dentin samples resulted in an increase of mineralization and a penetration of fluoride into enamel and dentin.
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http://dx.doi.org/10.1016/j.dental.2019.05.025DOI Listing
September 2019

Early Hearing Loss upon Disruption of Slc4a10 in C57BL/6 Mice.

J Assoc Res Otolaryngol 2019 06 18;20(3):233-245. Epub 2019 Apr 18.

Institute of Human Genetics, Jena University Hospital, Friedrich Schiller Universität, Am Klinikum 1, 07747, Jena, Germany.

The unique composition of the endolymph with a high extracellular K concentration is essential for sensory transduction in the inner ear. It is secreted by a specialized epithelium, the stria vascularis, that is connected to the fibrocyte meshwork of the spiral ligament in the lateral wall of the cochlea via gap junctions. In this study, we show that in mice the expression of the bicarbonate transporter Slc4a10/Ncbe/Nbcn2 in spiral ligament fibrocytes starts shortly before hearing onset. Its disruption in a C57BL/6 background results in early onset progressive hearing loss. This hearing loss is characterized by a reduced endocochlear potential from hearing onset onward and progressive degeneration of outer hair cells. Notably, the expression of a related bicarbonate transporter, i.e., Slc4a7/Nbcn1, is also lost in spiral ligament fibrocytes of Slc4a10 knockout mice. The histological analysis of the spiral ligament of Slc4a10 knockout mice does not reveal overt fibrocyte loss as reported for Slc4a7 knockout mice. The ultrastructural analysis, however, shows mitochondrial alterations in fibrocytes of Slc4a10 knockout mice. Our data suggest that Slc4a10 and Slc4a7 are functionally related and essential for inner ear homeostasis.
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http://dx.doi.org/10.1007/s10162-019-00719-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6514043PMC
June 2019

A mouse model for SPG48 reveals a block of autophagic flux upon disruption of adaptor protein complex five.

Neurobiol Dis 2019 07 28;127:419-431. Epub 2019 Mar 28.

Institute of Human Genetics, University Hospital Jena, Friedrich-Schiller-University Jena, Jena 07747, Germany. Electronic address:

Hereditary spastic paraplegia is a spastic gait disorder that arises from degeneration of corticospinal axons. The subtype SPG48 is associated with mutations in the zeta subunit of the adaptor protein complex five (AP5). AP5 function and the pathophysiology of SPG48 are only poorly understood. Here, we report an AP5 zeta knockout mouse, which shows an age-dependent degeneration of corticospinal axons. Our analysis of knockout fibroblasts supports a trafficking defect from late endosomes to the transGolgi network and reveals a structural defect of the Golgi. We further show that both autophagic flux and the recycling of lysosomes from autolysosomes were impaired in knockout cells. In vivo, we observe an increase of autophagosomes and autolysosomes and, at later stages, the accumulation of intracellular waste in neurons. Taken together, we propose that loss of AP5 function blocks autophagy and thus leads to the aberrant accumulation of autophagic cargo, which finally results in axon degeneration.
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http://dx.doi.org/10.1016/j.nbd.2019.03.026DOI Listing
July 2019

Microbial Fe(II) oxidation by Sideroxydans lithotrophicus ES-1 in the presence of Schlöppnerbrunnen fen-derived humic acids.

FEMS Microbiol Ecol 2019 04;95(4)

Institute of Biodiversity, Friedrich Schiller University Jena, Dornburger Strasse 159, D-07743 Jena, Germany.

Controlled laboratory experiments were combined with field measurements to better understand the interactions between dissolved organic matter (DOM) and reduced iron in organic-rich peatlands. Addition of peat-derived humic acid extract (HA) to Sideroxydans lithotrophicus ES-1 liquid cultures led to higher cell numbers and up to 1.4 times higher Fe(II) oxidation rates compared to chemical controls. This effect was positively correlated with increasing HA concentrations. Similar Fe(III) (oxyhydr)oxide mineralogies were formed both abiotically and biotically irrespective of HA amendment, but minerals formed in the presence of ES-1 and HA were smaller. ES-1 growth with HA promoted aggregation of Fe(III) products in agarose-stabilized gradient tubes as shown by voltammetric profiling. In situ voltammetry in an acidic, iron-rich peatland revealed a gap between oxygen penetration and iron reduction that may reflect active Fe(II)-oxidizing microorganisms. The highest abundance of Fe(II) oxidizers Sideroxydans (4.9 × 107 gene copies gww-1) and Gallionella (1.5 × 107 gene copies gww-1) in the upper peat layer coincided with small-sized minerals resembling nanoparticulate ferrihydrite or goethite. Our results suggest that microbially mediated Fe(II) oxidation dominates in the presence of DOM leading to the formation of nano-sized biogenic Fe(III) (oxyhydr)oxides that might be readily bioavailable and likely important to iron and carbon cycling.
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http://dx.doi.org/10.1093/femsec/fiz034DOI Listing
April 2019

Publisher Correction: ApoE attenuates unresolvable inflammation by complex formation with activated C1q.

Nat Med 2019 Mar;25(3):529

Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-University, Munich, Germany.

In the version of this article originally published, a sentence was erroneously included in the author contributions, and information regarding second shared authorship was missing from the author contributions. The following should not have been included in the author contributions: "C.W. and A.J.R.H. supervised the work presented in Figs. 1, 2, 5, 6; P.Z. and C.S. supervised the work presented in Figs. 3, 4." Additionally, this sentence should have appeared at the beginning of the author contributions: "These authors contributed equally: C.W., P.F.Z., C.S., and A.J.R.H." The errors have been corrected in the print, PDF and HTML versions of the article.
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http://dx.doi.org/10.1038/s41591-019-0378-6DOI Listing
March 2019

ApoE attenuates unresolvable inflammation by complex formation with activated C1q.

Nat Med 2019 03 28;25(3):496-506. Epub 2019 Jan 28.

Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximilians-University, Munich, Germany.

Apolipoprotein-E (ApoE) has been implicated in Alzheimer's disease, atherosclerosis, and other unresolvable inflammatory conditions but a common mechanism of action remains elusive. We found in ApoE-deficient mice that oxidized lipids activated the classical complement cascade (CCC), resulting in leukocyte infiltration of the choroid plexus (ChP). All human ApoE isoforms attenuated CCC activity via high-affinity binding to the activated CCC-initiating C1q protein (K~140-580 pM) in vitro, and C1q-ApoE complexes emerged as markers for ongoing complement activity of diseased ChPs, Aβ plaques, and atherosclerosis in vivo. C1q-ApoE complexes in human ChPs, Aβ plaques, and arteries correlated with cognitive decline and atherosclerosis, respectively. Treatment with small interfering RNA (siRNA) against C5, which is formed by all complement pathways, attenuated murine ChP inflammation, Aβ-associated microglia accumulation, and atherosclerosis. Thus, ApoE is a direct checkpoint inhibitor of unresolvable inflammation, and reducing C5 attenuates disease burden.
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http://dx.doi.org/10.1038/s41591-018-0336-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6420126PMC
March 2019

Proteome Analysis Reveals the Conidial Surface Protein CcpA Essential for Virulence of the Pathogenic Fungus .

mBio 2018 10 2;9(5). Epub 2018 Oct 2.

Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany

is a common airborne fungal pathogen of humans and a significant source of mortality in immunocompromised individuals. Here, we provide the most extensive cell wall proteome profiling to date of resting conidia, the fungal morphotype pertinent to first contact with the host. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), we identified proteins within the conidial cell wall by hydrogen-fluoride (HF)-pyridine extraction and proteins exposed on the surface using a trypsin-shaving approach. One protein, designated onidial ell wall rotein (CcpA), was identified by both methods and was found to be nearly as abundant as hydrophobic rodlet layer-forming protein RodA. CcpA, an amphiphilic protein, like RodA, peaks in expression during sporulation on resting conidia. Despite high cell wall abundance, the cell surface structure of Δ resting conidia appeared normal. However, trypsin shaving of Δ conidia revealed novel surface-exposed proteins not detected on conidia of the wild-type strain. Interestingly, the presence of swollen Δ conidia led to higher activation of neutrophils and dendritic cells than was seen with wild-type conidia and caused significantly less damage to epithelial cells In addition, virulence was highly attenuated when cortisone-treated, immunosuppressed mice were infected with Δ conidia. CcpA-specific memory T cell responses were detectable in healthy human donors naturally exposed to conidia, suggesting a role for CcpA as a structural protein impacting conidial immunogenicity rather than possessing a protein-intrinsic immunosuppressive effect. Together, these data suggest that CcpA serves as a conidial stealth protein by altering the conidial surface structure to minimize innate immune recognition. The mammalian immune system relies on recognition of pathogen surface antigens for targeting and clearance. In the absence of immune evasion strategies, pathogen clearance is rapid. In the case of , the successful fungus must avoid phagocytosis in the lung to establish invasive infection. In healthy individuals, fungal spores are cleared by immune cells; however, in immunocompromised patients, clearance mechanisms are impaired. Here, using proteome analyses, we identified CcpA as an important fungal spore protein involved in pathogenesis. lacking CcpA was more susceptible to immune recognition and prompt eradication and, consequently, exhibited drastically attenuated virulence. In infection studies, CcpA was required for virulence in infected immunocompromised mice, suggesting that it could be used as a possible immunotherapeutic or diagnostic target in the future. In summary, our report adds a protein to the list of those known to be critical to the complex fungal spore surface environment and, more importantly, identifies a protein important for conidial immunogenicity during infection.
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http://dx.doi.org/10.1128/mBio.01557-18DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6168859PMC
October 2018

The Actin Nucleator Cobl Is Critical for Centriolar Positioning, Postnatal Planar Cell Polarity Refinement, and Function of the Cochlea.

Cell Rep 2018 08;24(9):2418-2431.e6

Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, 07743 Jena, Germany. Electronic address:

Proper cochlear hair cell array development and sensory apparatus positioning are achieved by planar cell polarity signaling. Effectors executing proper tissue development and maturation programs are largely unknown. We show that the actin nucleator Cobl is an important effector in postnatal refinement and maintenance of planar cell polarity. During the critical time of hearing onset, these polarity defects coincided with reduced F-actin beneath the sensory apparatus and with premature kinocilium retraction. These defects were accompanied by organizational defects of the pericentriolar scaffold that coincided with basal body and centriolar mispositionings. Importantly, the pericentriolar defects observed in Cobl KO mice were demonstrated to be actin polymerization dependent and calcium/calmodulin signaling dependent. Because Cobl KO phenotypes manifested postnatally, planar cell polarity is not solely an important developmental process. The Cobl-dependent planar cell polarity maintenance and refinement processes we describe here seem critical for hearing, as Cobl KO mice show deficient cochlear amplification.
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http://dx.doi.org/10.1016/j.celrep.2018.07.087DOI Listing
August 2018

Molecular signatures of liver dysfunction are distinct in fungal and bacterial infections in mice.

Theranostics 2018 13;8(14):3766-3780. Epub 2018 Jun 13.

Department for Anesthesiology and Intensive Care Medicine, AG Nanophysiology, Jena University Hospital, Jena, Germany.

The liver is a central organ not only for metabolism but also immune function. Life-threatening infections of both bacterial and fungal origin can affect liver function but it is yet unknown whether molecular changes differ depending on the pathogen. We aimed to determine whether the hepatic host response to bacterial and fungal infections differs in terms of hepatic metabolism and liver function. We compared murine models of infection, including bacterial peritoneal contamination and infection (PCI), intraperitoneal and systemic infection, at 6 and 24 h post-infection, to sham controls. The molecular hepatic host response was investigated by the detection of regulatory modules based on large-scale protein-protein interaction networks and expression data. Topological analysis of these regulatory modules was used to reveal infection-specific biological processes and molecular mechanisms. Intravital microscopy and immunofluorescence microscopy were used to further analyze specific aspects of pathophysiology such as cholestasis. Down-regulation of lipid catabolism and bile acid synthesis was observed after 6 h in all infection groups. Alterations in lipid catabolism were characterized by accumulation of long chain acylcarnitines and defective beta-oxidation, which affected metabolism by 6 h. While PCI led to an accumulation of unconjugated bile acids (BA), infection caused accumulation of conjugated BA independent of the route of infection. Hepatic dye clearance and transporter expression revealed reduced hepatic uptake in fungal infections defects in secretion following polybacterial infection. Molecular phenotypes of lipid accumulation and cholestasis allow differentiation between pathogens as well as routes of infection at early stages in mice. Targeted metabolomics could be a useful tool for the profiling of infected/septic patients and the type of pathogen, with subsequent customization and targeting of therapy.
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http://dx.doi.org/10.7150/thno.24333DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6071540PMC
August 2019

The BEACH protein LRBA is required for hair bundle maintenance in cochlear hair cells and for hearing.

EMBO Rep 2017 11 11;18(11):2015-2029. Epub 2017 Sep 11.

Auditory Systems Physiology Group Department of Otolaryngology University Medical Center Göttingen, Göttingen, Germany

Lipopolysaccharide-responsive beige-like anchor protein (LRBA) belongs to the enigmatic class of BEACH domain-containing proteins, which have been attributed various cellular functions, typically involving intracellular protein and membrane transport processes. Here, we show that LRBA deficiency in mice leads to progressive sensorineural hearing loss. In LRBA knockout mice, inner and outer hair cell stereociliary bundles initially develop normally, but then partially degenerate during the second postnatal week. LRBA deficiency is associated with a reduced abundance of radixin and Nherf2, two adaptor proteins, which are important for the mechanical stability of the basal taper region of stereocilia. Our data suggest that due to the loss of structural integrity of the central parts of the hair bundle, the hair cell receptor potential is reduced, resulting in a loss of cochlear sensitivity and functional loss of the fraction of spiral ganglion neurons with low spontaneous firing rates. Clinical data obtained from two human patients with protein-truncating nonsense or frameshift mutations suggest that LRBA deficiency may likewise cause syndromic sensorineural hearing impairment in humans, albeit less severe than in our mouse model.
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http://dx.doi.org/10.15252/embr.201643689DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5666617PMC
November 2017

Activity of Fosfomycin- and Daptomycin-Containing Bone Cement on Selected Bacterial Species Being Associated with Orthopedic Infections.

Biomed Res Int 2017 6;2017:2318174. Epub 2017 Apr 6.

Center of Electron Microscopy, University Hospital of Jena, Ziegelmühlenweg 1, 07743 Jena, Germany.

The purpose of this study was to determine activity of fosfomycin/gentamicin and daptomycin/gentamicin-containing PMMA bone-cement against (MRSA, MSSA), , (VRE), and (ESBL; only fosfomycin). Test specimens of the bone cement were formed and bacteria in two concentrations were added one time or repeatedly up to 96 h. All fosfomycin-containing cement killed ultimately all MSSA, and within 24 h; growth of MRSA was suppressed up to 48 h. Activity of daptomycin-containing cement depended on the concentration; the highest concentrated bone cement used (1.5 g daptomycin/40 g of powder) was active against all one-time added bacteria. When bacteria were added repeatedly to fosfomycin-containing cement, growth was suppressed up to 96 h and that of MRSA and VRE only up to 24 h. The highest concentration of daptomycin suppressed the growth of repeated added bacteria up to 48 h (VRE) until 96 h (MSSA, MRSA). In conclusion, PMMA bone cement with 1.5 g of daptomycin and 0.5 g of gentamicin may be an alternative in treatment of periprosthetic infections caused by Gram-positive bacteria.
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http://dx.doi.org/10.1155/2017/2318174DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5397628PMC
February 2018
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