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Scanning electron microscopy preparation of the cellular actin cortex: A quantitative comparison between critical point drying and hexamethyldisilazane drying
2021, Schu, Moritz, Terriac, Emmanuel, Koch, Marcus, Paschke, Stephan, Lautenschlรคger, Franziska, Flormann, Daniel A.D.
The cellular cortex is an approximately 200-nm-thick actin network that lies just beneath the cell membrane. It is responsible for the mechanical properties of cells, and as such, it is involved in many cellular processes, including cell migration and cellular interactions with the environment. To develop a clear view of this dense structure, high-resolution imaging is essential. As one such technique, electron microscopy, involves complex sample preparation procedures. The final drying of these samples has significant influence on potential artifacts, like cell shrinkage and the formation of artifactual holes in the actin cortex. In this study, we compared the three most used final sample drying procedures: critical-point drying (CPD), CPD with lens tissue (CPD-LT), and hexamethyldisilazane drying. We show that both hexamethyldisilazane and CPD-LT lead to fewer artifactual mesh holes within the actin cortex than CPD. Moreover, CPD-LT leads to significant reduction in cell height compared to hexamethyldisilazane and CPD. We conclude that the final drying procedure should be chosen according to the reduction in cell height, and so CPD-LT, or according to the spatial separation of the single layers of the actin cortex, and so hexamethyldisilazane.
A new human adipocyte model with PTEN haploinsufficiency
2020, Kรคssner F., Kirstein A., Hรคndel N., Schmid G.L., Landgraf K., Berthold A., Tannert A., Schaefer M., Wabitsch M., Kiess W., Kรถrner A., Garten A.
Few human cell strains are suitable and readily available as in vitro adipocyte models. We used resected lipoma tissue from a patient with germline phosphatase and tensin homolog (PTEN) haploinsufficiency to establish a preadipocyte cell strain termed LipPD1 and aimed to characterize cellular functions and signalling pathway alterations in comparison to the established adipocyte model Simpson-Golabi-Behmel-Syndrome (SGBS) and to primary stromal-vascular fraction cells. We found that both cellular life span and the capacity for adipocyte differentiation as well as adipocyte-specific functions were preserved in LipPD1 and comparable to SGBS adipocytes. Basal and growth factor-stimulated activation of the PI3 K/AKT signalling pathway was increased in LipPD1 preadipocytes, corresponding to reduced PTEN levels in comparison to SGBS cells. Altogether, LipPD1 cells are a novel primary cell model with a defined genetic lesion suitable for the study of adipocyte biology. ยฉ 2020, ยฉ 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
Non-thermal plasma modulates cellular markers associated with immunogenicity in a model of latent HIV-1 infection
2021, Mohamed, Hager, Clemen, Ramona, Freund, Eric, Lackmann, Jan-Wilm, Wende, Kristian, Connors, Jennifer, Haddad, Elias K., Dampier, Will, Wigdahl, Brian, Miller, Vandana, Bekeschus, Sander, Krebs, Fred C., Kashanchi, Fatah
Effective control of infection by human immunodeficiency virus type 1 (HIV-1), the causative agent of the acquired immunodeficiency syndrome (AIDS), requires continuous and life-long use of anti-retroviral therapy (ART) by people living with HIV-1 (PLWH). In the absence of ART, HIV-1 reemergence from latently infected cells is ineffectively suppressed due to suboptimal innate and cytotoxic T lymphocyte responses. However, ART-free control of HIV-1 infection may be possible if the inherent immunological deficiencies can be reversed or restored. Herein we present a novel approach for modulating the immune response to HIV-1 that involves the use of non-thermal plasma (NTP), which is an ionized gas containing various reactive oxygen and nitrogen species (RONS). J-Lat cells were used as a model of latent HIV-1 infection to assess the effects of NTP application on viral latency and the expression of pro-phagocytic and pro-chemotactic damage-associated molecular patterns (DAMPs). Exposure of J-Lat cells to NTP resulted in stimulation of HIV-1 gene expression, indicating a role in latency reversal, a necessary first step in inducing adaptive immune responses to viral antigens. This was accompanied by the release of pro-inflammatory cytokines and chemokines including interleukin-1ฮฒ (IL-1ฮฒ) and interferon-ฮณ (IFN-ฮณ); the display of pro-phagocytic markers calreticulin (CRT), heat shock proteins (HSP) 70 and 90; and a correlated increase in macrophage phagocytosis of NTP-exposed J-Lat cells. In addition, modulation of surface molecules that promote or inhibit antigen presentation was also observed, along with an altered array of displayed peptides on MHC I, further suggesting methods by which NTP may modify recognition and targeting of cells in latent HIV-1 infection. These studies represent early progress toward an effective NTP-based ex vivo immunotherapy to resolve the dysfunctions of the immune system that enable HIV-1 persistence in PLWH.
Population ageing and deaths attributable to ambient PM2ยท5 pollution: a global analysis of economic cost
2021, Yin, Hao, Brauer, Michael, Zhang, Junfeng (Jim), Cai, Wenjia, Navrud, Stรฅle, Burnett, Richard, Howard, Courtney, Deng, Zhu, Kammen, Daniel M., Schellnhuber, Hans Joachim, Chen, Kai, Kan, Haidong, Chen, Zhan-Ming, Chen, Bin, Zhang, Ning, Mi, Zhifu, Coffman, D'Maris, Cohen, Aaron J., Guan, Dabo, Zhang, Qiang, Gong, Peng, Liu, Zhu
Background: The health impacts of ambient air pollution impose large costs on society. Although all people are exposed to air pollution, the older population (ie, those aged โฅ60 years) tends to be disproportionally affected. As a result, there is growing concern about the health impacts of air pollution as many countries undergo rapid population ageing. We investigated the spatial and temporal variation in the economic cost of deaths attributable to ambient air pollution and its interaction with population ageing from 2000 to 2016 at global and regional levels. Methods: In this global analysis, we developed an age-adjusted measure of the value of a statistical life-year (VSLY) to estimate the economic cost of deaths attributable to ambient PM2ยท5 pollution using Global Burden of Diseases, Injuries, and Risk Factors Study 2017 data and country-level socioeconomic information. First, we estimated the global age-specific and cause-specific mortality and years of life lost (YLLs) attributable to PM2ยท5 pollution using the global exposure mortality model and global estimates of exposure at 0ยท1ยฐ ร 0ยท1ยฐ (about 11 km ร 11 km at the equator) resolution. Second, for each year between 2000 and 2016, we translated the YLLs within each age group into a health-related cost using a country-specific, age-adjusted measure of VSLY. Third, we decomposed the major driving factors that contributed to the temporal change in health costs related to PM2ยท5. Finally, we did a sensitivity test to analyse the variability of the estimated health costs to four alternative valuation measures. We identified the uncertainty intervals (UIs) from 1000 draws of the parameters and concentrationโresponse functions by age, cause, country, and year. All economic values are reported in 2011 purchasing power parity-adjusted US dollars. All simulations were done with R, version 3.6.0. Findings: Globally, in 2016, PM2ยท5 was estimated to have caused 8ยท42 million (95% UI 6ยท50โ10ยท52) attributable deaths, which was associated with 163ยท68 million (116ยท03โ219ยท44) YLLs. In 2016, the global economic cost of deaths attributable to ambient PM2ยท5 pollution for the older population was US$2ยท40 trillion (1ยท89โ2ยท93) accounting for 59% (59โ60) of the cost for the total population ($4ยท09 trillion [3ยท19โ5ยท05]). The economic cost per capita for the older population was $2739 (2160โ3345) in 2016, which was 10 times that of the younger population (ie, those aged <60 years). By assessing the factors that contributed to economic costs, we found that increases in these factors changed the total economic cost by 77% for gross domestic product (GDP) per capita, 21% for population ageing, 16% for population growth, โ41% for age-specific mortality, and โ0ยท4% for PM2ยท5 exposure. Interpretation: The economic cost of ambient PM2ยท5 borne by the older population almost doubled between 2000 and 2016, driven primarily by GDP growth, population ageing, and population growth. Compared with younger people, air pollution leads to disproportionately higher health costs among older people, even after accounting for their relatively shorter life expectancy and increased disability. As the world's population is ageing, the disproportionate health cost attributable to ambient PM2ยท5 pollution potentially widens the health inequities for older people. Countries with severe air pollution and rapid ageing rates need to take immediate actions to improve air quality. In addition, strategies aimed at enhancing health-care services, especially targeting the older population, could be beneficial for reducing the health costs of ambient air pollution. Funding: National Natural Science Foundation of China, China Postdoctoral Science Foundation, and Qiushi Foundation.
Graphene oxide functional nanohybrids with magnetic nanoparticles for improved vectorization of doxorubicin to neuroblastoma cells
2019, Lerra, L., Farfalla, A., Sanz, B., Cirillo, G., Vittorio, O., Voli, F., Grand, M.L., Curcio, M., Nicoletta, F.P., Dubrovska, A., Hampel, S., Iemma, F., Goya, G.F.
With the aim to obtain a site-specific doxorubicin (DOX) delivery in neuroblastoma SH-SY5Y cells, we designed an hybrid nanocarrier combining graphene oxide (GO) and magnetic iron oxide nanoparticles (MNPs), acting as core elements, and a curcuminโhuman serum albumin conjugate as functional coating. The nanohybrid, synthesized by redox reaction between the MNPs@GO system and albumin bioconjugate, consisted of MNPs@GO nanosheets homogeneously coated by the bioconjugate as verified by SEM investigations. Drug release experiments showed a pH-responsive behavior with higher release amounts in acidic (45% at pH 5.0) vs. neutral (28% at pH 7.4) environments. Cell internalization studies proved the presence of nanohybrid inside SH-SY5Y cytoplasm. The improved efficacy obtained in viability assays is given by the synergy of functional coating and MNPs constituting the nanohybrids: while curcumin moieties were able to keep low DOX cytotoxicity levels (at concentrations of 0.44โ0.88 ยตM), the presence of MNPs allowed remote actuation on the nanohybrid by a magnetic field, increasing the dose delivered at the target site.
Breast Cancer Stem CellโDerived Tumors Escape from ฮณฮด T-cell Immunosurveillance In Vivo by Modulating ฮณฮด T-cell Ligands
2023, Raute, Katrin, Strietz, Juliane, Parigiani, Maria Alejandra, Andrieux, Geoffroy, Thomas, Oliver S., Kistner, Klaus M., Zintchenko, Marina, Aichele, Peter, Hofmann, Maike, Zhou, Houjiang, Weber, Wilfried, Boerries, Melanie, Swamy, Mahima, Maurer, Jochen, Minguet, Susana
There are no targeted therapies for patients with triple-negative breast cancer (TNBC). TNBC is enriched in breast cancer stem cells (BCSC), which play a key role in metastasis, chemoresistance, relapse, and mortality. ฮณฮด T cells hold great potential in immunotherapy against cancer and might provide an approach to therapeutically target TNBC. ฮณฮด T cells are commonly observed to infiltrate solid tumors and have an extensive repertoire of tumor-sensing mechanisms, recognizing stress-induced molecules and phosphoantigens (pAgs) on transformed cells. Herein, we show that patient-derived triple-negative BCSCs are efficiently recognized and killed by ex vivo expanded ฮณฮด T cells from healthy donors. Orthotopically xenografted BCSCs, however, were refractory to ฮณ ฮด T-cell immunotherapy. We unraveled concerted differentiation and immune escape mechanisms: xenografted BCSCs lost stemness, expression of ฮณ ฮด T-cell ligands, adhesion molecules, and pAgs, thereby evading immune recognition by ฮณ ฮด T cells. Indeed, neither promigratory engineered ฮณ ฮด T cells, nor antiโPD-1 checkpoint blockade, significantly prolonged overall survival of tumor-bearing mice. BCSC immune escape was independent of the immune pressure exerted by the ฮณ ฮด T cells and could be pharmacologically reverted by zoledronate or IFNฮฑ treatment. These results pave the way for novel combinatorial immunotherapies for TNBC.
The role of risk communication in public health interventions. An analysis of risk communication for a community quarantine in Germany to curb the SARS-CoV-2 pandemic
2021, Scholz, Juliane, Wetzker, Wibke, Licht, Annika, Heintzmann, Rainer, Scherag, Andrรฉ, Weis, Sebastian, Pletz, Mathias, Betsch, Cornelia, Bauer, Michael, Dickmann, Petra, Frey, Rosemary
Background: Separating ill or possibly infectious people from their healthy community is one of the core principles of non-pharmaceutical interventions. However, there is scarce evidence on how to successfully implement quarantine orders. We investigated a community quarantine for an entire village in Germany (Neustadt am Rennsteig, March 2020) with the aim of better understanding the successful implementation of quarantine measures. Methods: This cross-sectional survey was conducted in Neustadt am Rennsteig six weeks after the end of a 14-day mandatory community quarantine. The sample size consisted of 562 adults (64% of the community), and the response rate was 295 adults, or 52% (33% of the community). Findings: National television was reported as the most important channel of information. Contact with local authorities was very limited, and partners or spouses played a more important role in sharing information. Generally, the self-reported information level was judged to be good (211/289 [73.0%]). The majority of participants (212/289 [73.4%]) approved of the quarantine, and the reported compliance was 217/289 (75.1%). A self-reported higher level of concern as well as a higher level of information correlated positively with both a greater acceptance of quarantine and self-reported compliant behaviour. Interpretation: The community quarantine presented a rare opportunity to investigate a public health intervention for an entire community. In order to improve the implementation of public health interventions, public health risk communication activities should be intensified to increase both the information level (potentially leading to better compliance with community quarantine) and the communication level (to facilitate rapport and trust between public health authorities and their communities). ยฉ 2021 Scholz et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Complete Genome Sequence of a New Ruminococcaceae Bacterium Isolated from Anaerobic Biomass Hydrolysis
2018, Hahnke, Sarah, Abendroth, Christian, Langer, Thomas, Codoรฑer, Francisco M., Ramm, Patrice, Porcar, Manuel, Luschnig, Olaf, Klocke, Michael
A new Ruminococcaceae bacterium, strain HV4-5-B5C, participating in the anaerobic digestion of grass, was isolated from a mesophilic two-stage laboratoryscale leach bed biogas system. The draft annotated genome sequence presented in this study and 16S rRNA gene sequence analysis indicated the affiliation of HV4-5- B5C with the family Ruminococcaceae outside recently described genera. ยฉ 2018 Hahnke et al.
Effects of new beta-type Ti-40Nb implant materials, brain-derived neurotrophic factor, acetylcholine and nicotine on human mesenchymal stem cells of osteoporotic and non osteoporotic donors
2018, Kauschke, V., Gebert, A., Calin, M., Eckert, J., Scheich, S., Heiss, C., Lips, K.S.
Introduction Treatment of osteoporotic fractures is still challenging and an urgent need exists for new materials, better adapted to osteoporotic bone by adjusted Youngโs modulus, appropriate surface modification and pharmaceuticals. Materials and methods Titanium-40-niobium alloys, mechanically ground or additionally etched and titanium-6-alu-minium-4-vanadium were analyzed in combination with brain-derived neurotrophic factor, acetylcholine and nicotine to determine their effects on human mesenchymal stem cells in vitro over 21 days using lactate dehydrogenase and alkaline phosphatase assays, live cell imaging and immunofluorescence microscopy. Results Cell number of human mesenchymal stem cells of osteoporotic donors was increased after 14 d in presence of ground titanium-40-niobium or titanium-6-aluminium-4-vanadium, together with brain-derived neurotrophic factor. Cell number of human mesenchymal stem cells of non osteoporotic donors increased after 21 d in presence of titanium-6-aluminium-4-vanadium without pharmaceuticals. No significant increase was measured for ground or etched titanium-40-niobium after 21 d. Osteoblast differentiation of osteoporotic donors was significantly higher than in non osteoporotic donors after 21 d in presence of etched, ground titanium-40-niobium or titanium-6-aluminium-4-vanadium accompanied by all pharmaceuticals tested. In presence of all alloys tested brain-derived neurotrophic factor, acetylcholine and nicotine increased differentiation of cells of osteoporotic donors and accelerated it in non osteoporotic donors. Conclusion We conclude that ground titanium-40-niobium and brain-derived neurotrophic factor might be most suitable for subsequent in vivo testing.
Association between population distribution and urban GDP scaling
2021, Ribeiro, Haroldo V., Oehlers, Milena, Moreno-Monroy, Ana I, Kropp, Jรผrgen P., Rybski, Diego
Urban scaling and Zipfโs law are two fundamental paradigms for the science of cities. These laws have mostly been investigated independently and are often perceived as disassociated matters. Here we present a large scale investigation about the connection between these two laws using population and GDP data from almost five thousand consistently-defined cities in 96 countries. We empirically demonstrate that both laws are tied to each other and derive an expression relating the urban scaling and Zipf exponents. This expression captures the average tendency of the empirical relation between both exponents, and simulations yield very similar results to the real data after accounting for random variations. We find that while the vast majority of countries exhibit increasing returns to scale of urban GDP, this effect is less pronounced in countries with fewer small cities and more metropolises (small Zipf exponent) than in countries with a more uneven number of small and large cities (large Zipf exponent). Our research puts forward the idea that urban scaling does not solely emerge from intra-city processes, as population distribution and scaling of urban GDP are correlated to each other.