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Purpose: Viruses, such as Ebola virus (EBOV), evolve rapidly and threaten the human health. There is a great demand to exploit efficient gene-editing techniques for the identification of virus to probe virulence mechanism for drug development. Methods: Based on lambda Red recombination in Escherichia coli (E. coli), counter-selection, and in vitro annealing, a high-efficiency genetic method was utilized here for precisely engineering viruses. EBOV trVLPs assay and dual luciferase reporter assay were used to further test the effect of mutations on virus replication. Results: Considering the significance of matrix protein VP24 in EBOV replication, the types of mutations within vp24, including several single-base substitutions, one double-base substitution, two seamless deletions, and one targeted insertion, were generated on the multi-copy plasmid of E. coli. Further, the length of the homology arms for recombination and in vitro annealing, and the amount of DNA cassettes and linear plasmids were optimized to create a more elaborate and cost-efficient protocol than original approach. The effects of VP24 mutations on the expression of a reporter gene (luciferase) from the EBOV minigenome were determined, and results indicated that mutations of key sites within VP24 have significant impacts on EBOV replication. Conclusion: This precise mutagenesis method will facilitate effective and simple editing of viral genes in E. coli. [ABSTRACT FROM AUTHOR]

Magnetic loss electromagnetic wave absorber materials have always been a research hotspot in the electromagnetic wave absorption field due to their excellent magnetic loss performance. However, their use is limited by the problem of impedance mismatch. In this study, taking into account the good soft magnetic properties and high amorphous forming ability of the FeSiBCCr amorphous alloy system, the spherical powder was transformed into a flaky powder through high-energy ball milling and uniformly mixed with a certain mass ratio of paraffin to produce high performance wave absorber. It was found that, compared with spherical powders, the flaky powder particles mixed with paraffin not only enlarged the surface area of the filler and improved the mechanism of polarization, but also increased the complex permeability and complex permittivity, thus providing strong electromagnetic wave attenuation capability. The flaky amorphous powder after ball milling for 4 h shows the highest electromagnetic wave absorption performance, and the minimum reflectivity loss at the frequency of 9.25 GHz reaches − 40.82 dB when the thickness of the wave absorber (50 vol% powder) is 2.5 mm. The maximum effective absorption bandwidth is up to 4.9 GHz. The FeSiBCCr flaky amorphous powder prepared in this work shows a broad absorption potential above 18 GHz, which can well solve the impedance mismatch problem, and provides a strategy for the synthesis of magnetic loss electromagnetic wave-absorbing materials with impedance matching and broad absorption strength. [ABSTRACT FROM AUTHOR]

Malignant tumor has always been a complex disease that endangers human health. Traditional treatment methods include surgical resection, chemotherapy, and radiotherapy. However, solid tumors are prone to recur. Herein, we developed a hydrogel-based drug-carrying system to prevent postoperative tumor recurrence. Sodium carboxymethyl cellulose was modified with dopamine via the N-hydroxysuccinimide (NHS) and 1-ethyl-(3-dimethylaminopropyl) carbanyl diimide (EDC)-mediated coupling chemistry. The CMC-DA-MnO2/MnO (CDM) hydrogel was prepared by oxidative cross-linking, using KMnO4 as the oxidizing agent. In the hydrogel, the KMnO4 can not only be used as an oxidant to trigger the polymerization and gelation of CMC-DA but also transformed into MnO2 and MnO to afford the T2-weighted magnetic resonance imaging (MRI). The fluorescent dye IR808 as a photosensitizer was introduced into the hydrogel system by simply soaking the CDM hydrogel in the IR808 solution. Under the 808 nm laser irradiation, IR808 and PDA endowed the hydrogel with tumor photodynamic therapy (PDT) and photothermal therapy (PTT) capacities, respectively. With the proven hemo- and cyto-compatibilities, the CDM hydrogel was successfully used for the PDT and PTT prevention of postoperative tumor recurrence. [ABSTRACT FROM AUTHOR]

As a critical node for insulin/IGF signaling, insulin receptor substrate 1 (IRS-1) is essential for metabolic regulation. A long and unstructured C-terminal region of IRS-1 recruits downstream effectors for promoting insulin/IGF signals. However, the underlying molecular basis for this remains elusive. Here, we found that the C-terminus of IRS-1 undergoes liquid-liquid phase separation (LLPS). Both electrostatic and hydrophobic interactions were seen to drive IRS-1 LLPS. Self-association of IRS-1, which was mainly mediated by the 301–600 region, drives IRS-1 LLPS to form insulin/IGF-1 signalosomes. Moreover, tyrosine residues of YXXM motifs, which recruit downstream effectors, also contributed to IRS-1 self-association and LLPS. Impairment of IRS-1 LLPS attenuated its positive effects on insulin/IGF-1 signaling. The metabolic disease-associated G972R mutation impaired the self-association and LLPS of IRS-1. Our findings delineate a mechanism in which LLPS of IRS-1-mediated signalosomes serves as an organizing center for insulin/IGF-1 signaling and implicate the role of aberrant IRS-1 LLPS in metabolic diseases. [ABSTRACT FROM AUTHOR]

Microglia are highly motile cells that act as the main form of active immune defense in the central nervous system. Attracted by factors released from damaged cells, microglia are recruited towards the damaged or infected site, where they are involved in degenerative and regenerative responses and phagocytotic clearance of cell debris. ATP release from damaged neural tissues has been suggested to mediate the rapid extension of microglial process towards the site of injury. However, the mechanisms of the long-range migration of microglia remain to be clarified. Here, we found that lysosomes in microglia contain abundant ATP and exhibit Ca2+-dependent exocytosis in response to various stimuli. By establishing an efficient in vitro chemotaxis assay, we demonstrated that endogenously-released ATP from microglia triggered by local microinjection of ATPγS is critical for the long-range chemotaxis of microglia, a response that was significantly inhibited in microglia treated with an agent inducing lysosome osmodialysis or in cells derived from mice deficient in Rab 27a (ashen mice), a small GTPase required for the trafficking and exocytosis of secretory lysosomes. These results suggest that microglia respond to extracellular ATP by releasing ATP themselves through lysosomal exocytosis, thereby providing a positive feedback mechanism to generate a long-range extracellular signal for attracting distant microglia to migrate towards and accumulate at the site of injury. [ABSTRACT FROM AUTHOR]