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991.
Atomic force microscope elastography reveals phenotypic differences in alveolar cell stiffness. 总被引:1,自引:0,他引:1
Evren U Azeloglu Jahar Bhattacharya Kevin D Costa 《Journal of applied physiology》2008,105(2):652-661
To understand the connection between alveolar mechanics and key biochemical events such as surfactant secretion, one first needs to characterize the underlying mechanical properties of the lung parenchyma and its cellular constituents. In this study, the mechanics of three major cell types from the neonatal rat lung were studied; primary alveolar type I (AT1) and type II (AT2) epithelial cells and lung fibroblasts were isolated using enzymatic digestion. Atomic force microscopy indentation was used to map the three-dimensional distribution of apparent depth-dependent pointwise elastic modulus. Histograms of apparent modulus data from all three cell types indicated non-Gaussian distributions that were highly skewed and appeared multimodal for AT2 cells and fibroblasts. Nuclear stiffness in all three cell types was similar (2.5+/-1.0 kPa in AT1 vs. 3.1+/-1.5 kPa in AT2 vs. 3.3+/-0.8 kPa in fibroblasts; n=10 each), whereas cytoplasmic moduli were significantly higher in fibroblasts and AT2 cells (6.0+/-2.3 and 4.7+/-2.9 kPa vs. 2.5+/-1.2 kPa). In both epithelial cell types, actin was arranged in sparse clusters, whereas prominent actin stress fibers were observed in lung fibroblasts. No systematic difference in actin or microtubule organization was noted between AT1 and AT2 cells. Atomic force microscope elastography, combined with live-cell fluorescence imaging, revealed that the stiffer measurements in AT2 cells often colocalized with lamellar bodies. These findings partially explain reported heterogeneity of alveolar cell deformation during in situ lung inflation and provide needed data for better understanding of how mechanical stretch influences surfactant release. 相似文献
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Julian?SchraderView authors OrcID profile Sybille?B.?Unsicker Samik?Bhattacharya Klaus?MummenhoffEmail author 《Plant Systematics and Evolution》2017,303(5):653-662
Volatile organic compounds (VOCs) released from plants are known to mediate indirect defense against herbivores and trigger intra- and interplant signaling. While systemic defense response can be mediated both via volatile and vascular signals, it is not clear whether common ancestry and/or plant growth forms influence the choice of either mode in planta. We hypothesize that larger woody plants with a complex anatomy should rely more on volatile-mediated signaling, apparently to circumvent vascular restrictions that slow down the communication over a large distance. On the other hand, in smaller herbaceous plants faster systemic response can be achieved via vascular signaling. To investigate whether plant VOCs emission is related to plant phylogeny or growth form, we studied the composition of herbivory-induced plant volatiles in 13 Brassicaceae species representing all four evolutionary lineages, because this family is characterized by both a well-resolved phylogeny and highly diverse growth forms. Our results revealed that woody species consistently emitted a more complex blend of volatiles than herbaceous species. However, phylogenetic relatedness of the species did not explain the observed volatile emission patterns. This emphasizes the influence of growth form, rather than phylogenetic relationships on the variation in plant volatile emissions. Our findings suggest that woody, perennial plant species emit diverse VOCs, likely because these compounds comprise a more efficient mode of defense response in these large, anatomically complex plants. 相似文献
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Deepshikha Verma Mutyala Sakuntala Aruna Murmu Alok Bhattacharya Kandala V. R. Chary 《Biomolecular NMR assignments》2017,11(1):63-67
We report almost complete sequence specific 1H, 13C and 15N NMR assignments of an unusual Ca2+-binding protein from Entamoeba histolytica (EhCaBP6) in its apo form as a prelude to its structural and functional characterization. 相似文献
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A PTS EII mutant library in Group A Streptococcus identifies a promiscuous man‐family PTS transporter influencing SLS‐mediated hemolysis
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Ganesh S. Sundar Emrul Islam Kanika Gera Yoann Le Breton Kevin S. McIver 《Molecular microbiology》2017,103(3):518-533
The Group A Streptococcus (GAS, Streptococcus pyogenes) is a Gram‐positive human pathogen that must adapt to unique host environments in order to survive. Links between sugar metabolism and virulence have been demonstrated in GAS, where mutants in the phosphoenolpyruvate‐dependent phosphotransferase system (PTS) exhibited Streptolysin S (SLS)‐mediated hemolysis during exponential growth. This early onset hemolysis correlated with an increased lesion size and severity in a murine soft tissue infection model when compared with parental M1T1 MGAS5005. To identify the PTS components responsible for this phenotype, we insertionally inactivated the 14 annotated PTS EIIC‐encoding genes in the GAS MGAS5005 genome and subjected this library to metabolic and hemolysis assays to functionally characterize each EIIC. It was found that a few EIIs had a very limited influence on PTS sugar metabolism, whereas others were fairly promiscuous. The mannose‐specific EII locus, encoded by manLMN, was expressed as a mannose‐inducible operon that exhibited the most influence on PTS sugar metabolism, including mannose. Importantly, components of the mannose‐specific EII also acted to prevent the early onset of SLS‐mediated hemolysis. Interestingly, these roles were not identical in two different M1T1 GAS strains, highlighting the possible versatility of the PTS to adapt to strain‐specific needs. 相似文献
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Polycyclic aromatic hydrocarbons and volatile organic compounds in biochar and biochar‐amended soil: a review
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Tanushree Dutta Eilhann Kwon Satya Sundar Bhattacharya Byong Hun Jeon Akash Deep Minori Uchimiya Ki‐Hyun Kim 《Global Change Biology Bioenergy》2017,9(6):990-1004
Residual pollutants including polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), and carbon (aceous) nanoparticles are inevitably generated during the pyrolysis of waste biomass and remain on the solid coproduct called biochar. Such pollutants could have adverse effects on the plant growth as well as microbial community in soil. Although biochar has been proposed as a ‘carbon negative strategy’ to mitigate the greenhouse gas emissions, the impacts of its application with respect to long‐term persistence and bioavailability of hazardous components are not clear. Moreover, the co‐occurrence of low molecular weight VOCs with PAHs in biochar may exert further phytotoxic effects. This review describes the basic need to unravel key mechanisms driving the storage vs. emission of these organics and the dynamics between the sorbent (biochar) and soil microbes. Moreover, there is an urgent need for standardized methods for quantitative analysis of PAHs and VOCs in biochar under environmentally relevant conditions. This review is also extended to cover current research gaps including the influence of biochar application on the short‐ and long‐term fate of PAHs and VOCs and the proper control tactics for biochar quality and associated risk. 相似文献