NOD2/RICK-dependent β-defensin 2 regulation is protective for nontypeable Haemophilus influenzae-induced middle ear infection.

Middle ear infection, otitis media (OM), is clinically important due to the high incidence in children and its impact on the development of language and motor coordination. Previously, we have demonstrated that the human middle ear epithelial cells up-regulate β-defensin 2, a model innate immune molecule, in response to nontypeable Haemophilus influenzae (NTHi), the most common OM pathogen, via TLR2 signaling. NTHi does internalize into the epithelial cells, but its intracellular trafficking and host responses to the internalized NTHi are poorly understood. Here we aimed to determine a role of cytoplasmic pathogen recognition receptors in NTHi-induced β-defensin 2 regulation and NTHi clearance from the middle ear. Notably, we observed that the internalized NTHi is able to exist freely in the cytoplasm of the human epithelial cells after rupturing the surrounding membrane. The human middle ear epithelial cells inhibited NTHi-induced β-defensin 2 production by NOD2 silencing but augmented it by NOD2 over-expression. NTHi-induced β-defensin 2 up-regulation was attenuated by cytochalasin D, an inhibitor of actin polymerization and was enhanced by α-hemolysin, a pore-forming toxin. NOD2 silencing was found to block α-hemolysin-mediated enhancement of NTHi-induced β-defensin 2 up-regulation. NOD2 deficiency appeared to reduce inflammatory reactions in response to intratympanic inoculation of NTHi and inhibit NTHi clearance from the middle ear. Taken together, our findings suggest that a cytoplasmic release of internalized NTHi is involved in the pathogenesis of NTHi infections, and NOD2-mediated β-defensin 2 regulation contributes to the protection against NTHi-induced otitis media

Translating Hanja Historical Documents to Contemporary Korean and English

The Annals of Joseon Dynasty (AJD) contain the daily records of the Kings of Joseon, the 500-year kingdom preceding the modern nation of Korea. The Annals were originally written in an archaic Korean writing system, `Hanja', and were translated into Korean from 1968 to 1993. The resulting translation was however too literal and contained many archaic Korean words; thus, a new expert translation effort began in 2012. Since then, the records of only one king have been completed in a decade. In parallel, expert translators are working on English translation, also at a slow pace and produced only one king's records in English so far. Thus, we propose H2KE, a neural machine translation model, that translates historical documents in Hanja to more easily understandable Korean and to English. Built on top of multilingual neural machine translation, H2KE learns to translate a historical document written in Hanja, from both a full dataset of outdated Korean translation and a small dataset of more recently translated contemporary Korean and English. We compare our method against two baselines: a recent model that simultaneously learns to restore and translate Hanja historical document and a Transformer based model trained only on newly translated corpora. The experiments reveal that our method significantly outperforms the baselines in terms of BLEU scores for both contemporary Korean and English translations. We further conduct extensive human evaluation which shows that our translation is preferred over the original expert translations by both experts and non-expert Korean speakers.Comment: 2022 EMNLP Finding

Characterization of Curli A Production on Living Bacterial Surfaces by Scanning Probe Microscopy

AbstractCurli are adhesive surface fibers produced by many Enterobacteriaceae, such as Escherichia coli and Salmonella enterica. They are implicated in bacterial attachment and invasion to epithelial cells. In this study, atomic force microscopy was used to determine the effects of curli on topology and mechanical properties of live E. coli cells. Young's moduli of both curli-deficient and curli-overproducing mutants were significantly lower than that of their wild-type (WT) strain, while decay lengths of the former strains were higher than that of the latter strain. Surprisingly, topological images showed that, unlike the WT and curli-overproducing mutant, the curli-deficient mutant produced a large number of flagella-like fibers, which may explain why the strain had a lower Young's modulus than the WT. These results suggest that the mechanical properties of bacterial surfaces are greatly affected by the presence of filamentous structures such as curli and flagella

Bucillamine prevents cisplatin-induced ototoxicity through induction of glutathione and antioxidant genes.

Bucillamine is used for the treatment of rheumatoid arthritis. This study investigated the protective effects of bucillamine against cisplatin-induced damage in auditory cells, the organ of Corti from postnatal rats (P2) and adult Balb/C mice. Cisplatin increases the catalytic activity of caspase-3 and caspase-8 proteases and the production of free radicals, which were significantly suppressed by pretreatment with bucillamine. Bucillamine induces the intranuclear translocation of Nrf2 and thereby increases the expression of γ-glutamylcysteine synthetase (γ-GCS) and glutathione synthetase (GSS), which further induces intracellular antioxidant glutathione (GSH), heme oxygenase 1 (HO-1) and superoxide dismutase 2 (SOD2). However, knockdown studies of HO-1 and SOD2 suggest that the protective effect of bucillamine against cisplatin is independent of the enzymatic activity of HO-1 and SOD. Furthermore, pretreatment with bucillamine protects sensory hair cells on organ of Corti explants from cisplatin-induced cytotoxicity concomitantly with inhibition of caspase-3 activation. The auditory-brainstem-evoked response of cisplatin-injected mice shows marked increases in hearing threshold shifts, which was markedly suppressed by pretreatment with bucillamine in vivo. Taken together, bucillamine protects sensory hair cells from cisplatin through a scavenging effect on itself, as well as the induction of intracellular GSH

The implication of glycans on the ACE2: SARS-CoV-2 spike interaction

Since its emergence in 2019 the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) continues to a profoundly impact and threaten human health. For the development of novel prophylactic and therapeutic measures a detailed understanding of the virus-host interaction and features that modulate the interaction is of utmost importance. Attachment of the SARS-CoV-2 virus to human host cells predominantly relies on the specific interaction of the viral spike (S) surface glycoprotein with the receptor angiotensin-converting enzyme 2 (ACE-2). Glycans within or surrounding the binding interface have been demonstrated to play an important role in the ACE2:S interaction. The quality of this interaction is multifaceted and affected by several parameters, such as the speed, the number, the strength and duration of bond formation. As mutations within the coding sequences of the interaction partners may affect their binding capacity, they should be thoroughly studied. In this respect, viral evolution and the effect of mutations within the S-protein have received much attention, while human ACE2 polymorphisms naturally occurring throughout the population have so far been largely ignored. Of note, natural ACE2 polymorphisms and viral spike mutants that result in the loss of glycans within the binding interface should receive our particular attention. Please click Download on the upper right corner to see the full abstract

Molecular Recognition in Confined Space Elucidated with DNA Nanopores and Single-Molecule Force Microscopy

The binding of ligands to receptors within a nanoscale small space is relevant in biology, biosensing, and affinity filtration. Binding in confinement can be studied with biological systems but under the limitation that essential parameters cannot be easily controlled including receptor type and position within the confinement and its dimensions. Here we study molecular recognition with a synthetic confined nanopore with controllable pore dimension and molecular DNA receptors at different depth positions within the channel. Binding of a complementary DNA strand is studied at the single-molecule level with atomic force microscopy. Following the analysis, kinetic association rates are lower for receptors positioned deeper inside the pore lumen while dissociation is faster and requires less force. The phenomena are explained by the steric constraints on molecular interactions in confinement. Our study is the first to explore recognition in DNA nanostructures with atomic force microscopy and lays out new tools to further quantify the effect of nanoconfinement on molecular interactions

Molecular Analysis of X-linked Chronic Granulomatous Disease in Five Unrelated Korean Patients

Chronic granulomatous disease (CGD) is a fatal genetic disorder in which phagocytes fail to produce antimicrobial superoxide because of NADPH oxidase deficiency. Molecular defects in CYBB gene causing X-linked CGD are responsible for about 70% of all cases. This study was done to confirm genetic defects of CYBB gene in five Korean patients who were highly suggestive of having CGD by clinical history. We performed initial screening for five unrelated Korean patients using single strand conformation polymorphism (SSCP) and then selective sequencing for the regions involving the abnormal bands. Activated NBT tests revealed that all patients were X-linked. SSCP analysis for CYBB gene showed abnormal bands in all patients. The molecular defects of five patients were as follows: c.1663insT, c.1111-1G>T, c.39_40insG, c.927delC and c.434T>C mutation. This result will help the families with prenatal diagnosis or genetic counseling

5′-Triphosphate-RNA-independent activation of RIG-I via RNA aptamer with enhanced antiviral activity

RIG-I is a cytosolic receptor for non-self RNA that mediates immune responses against viral infections through IFNα/β production. In an attempt to identify novel tools that modulate IFNα/β production, we used SELEX technology to screen RNA aptamers that specifically target RIG-I protein. Most of the selected RIG-I aptamers contained polyU motifs in the second half regions that played critical roles in the activation of RIG-I-mediated IFNβ production. Unlike other known ligands, RIG-I aptamer bound and activated RIG-I in a 5′-triphosphate-independent manner. The helicase and RD domain of RIG-I were used for aptamer binding, but intact RIG-I protein was required to exert aptamer-mediated signaling activation. Furthermore, replication of NDV, VSV and influenza virus in infected host cells was efficiently blocked by pre- or post-treatment with RIG-I aptamer. Based on these data, we propose that RIG-I aptamer has strong potential to be an antiviral agent that specifically boosts the RIG-I-dependent signaling cascade