Protection from avian influenza H5N1 virus infection with antibody-impregnated filters

There is worldwide concern over the possibility of a new influenza pandemic originating from the highly pathogenic avian H5N1 influenza viruses. We herein demonstrate that functional air filters impregnated with ostrich antibodies against the hemagglutinin of the H5N1 virus protect chickens from death by H5N1 transmission. These results suggest that the use of ostrich antibody-impregnated filters might be a powerful way to prevent the transmission of H5N1

Chronic hyperglycemia reduces the expression of intercellular adhesion molecules and increases intercellular hyperpermeability in the periodontal epithelium

This is the peer reviewed version of the following article: Narukawa Y., Sugiyama N., Miura J., et al. Chronic hyperglycemia reduces the expression of intercellular adhesion molecules and increases intercellular hyperpermeability in the periodontal epithelium. Journal of Periodontal Research 58, 813 (2023), which has been published in final form at https://doi.org/10.1111/jre.13140 This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.Background/Aims: Hyperglycemia in diabetes is closely associated with periodontal disease progression. This study aimed to investigate the effect of hyperglycemia on the barrier function of gingival epithelial cells as a cause of hyperglycemia-exacerbated periodontitis in diabetes mellitus. Methods: The abnormal expression of adhesion molecules in gingival epithelium in diabetes was compared between db/db and control mice. To study the effects of hyperglycemia on interepithelial cell permeability, the mRNA and protein expressions of adhesion molecules were investigated using a human gingival epithelial cell line (epi 4 cells) in the presence of either 5.5 mM glucose (NG) or 30 mM glucose (HG). Immunocytochemical and histological analyses were performed. We also studied HG-related intracellular signaling to assess abnormal adhesion molecule expression in the cultured epi 4 cells. Results: The results of the proteomic analysis implied the abnormal regulation of cell–cell adhesion, and mRNA and protein expression assessments revealed the significant downregulation of Claudin1 expression in the gingival tissues of db/db mice (p <.05 vs control). Similarly, the mRNA and protein expressions of adhesion molecules were lower in epi 4 cells cultured under HG conditions than in those cultured under NG conditions (p <.05). Three-dimensional culture and transmission electron microscopy revealed reduced thickness of the epithelial cell layers with no flattened apical cells and heterogeneously arranged intercellular spaces among adjacent epi 4 cells under the HG. These results were consistent with the increased permeability of epi 4 cells under the HG relative to that of cells under the NG. This abnormal expression of intercellular adhesion molecules under the HG was related to the increased expression of receptors for advanced glycation end products (AGEs) and oxidative stress relative to that seen under the NG, along with stimulation of ERK1/2 phosphorylation in epi 4 cells. Conclusions: High glucose-induced impairment of intercellular adhesion molecule expression in gingival epithelial cells was related to the intercellular permeability of gingival cells, representing a possible link to hyperglycemia-related AGE signaling, oxidative stress, and ERK1/2 activation

The constant threat from a non-native predator increases tail muscle and fast-start swimming performance in Xenopus tadpoles

Predator-induced phenotypic plasticity is the ability of prey to adapt to their native predator. However, owing to environmental changes, encounters with unknown predators are inevitable. Therefore, study of prey and non-native predator interaction will reveal the primary stages of adaptive strategies in prey-predator interactions in the context of evolutionary processes. Here, Xenopus tadpoles exposed to a non-native predator, a larval salamander, showed a significant increase in body weight and tail length to body length ratio. The Tmax2 test indicated a significant enhancement of the tail muscle and decrease in the relative ventral fin height in tadpoles exposed to predation risk, leading to significantly higher average swimming speeds. The analysis of muscle-related metabolites revealed that sarcosine increased significantly in tadpoles exposed to non-native predators. Multiple linear regression analysis of the fast-start swimming pattern showed that the fast-start swimming speed was determined by the time required for a tadpole to bend its body away from the threat (C-start) and the angle at which it was bent. In conclusion, morphological changes in tadpoles were functionally adaptive and induced by survival behaviors of Xenopus tadpoles against non-native predators

Predation threats for a 24-h period activated the extension of axons in the brains of Xenopus tadpoles

Abstract The threat of predation is a driving force in the evolution of animals. We have previously reported that Xenopus laevis enhanced their tail muscles and increased their swimming speeds in the presence of Japanese larval salamander predators. Herein, we investigated the induced gene expression changes in the brains of tadpoles under the threat of predation using 3′-tag digital gene expression profiling. We found that many muscle genes were expressed after 24 h of exposure to predation. Ingenuity pathway analysis further showed that after 24 h of a predation threat, various signal transduction genes were stimulated, such as those affecting the actin cytoskeleton and CREB pathways, and that these might increase microtubule dynamics, axonogenesis, cognition, and memory. To verify the increase in microtubule dynamics, DiI was inserted through the tadpole nostrils. Extension of the axons was clearly observed from the nostril to the diencephalon and was significantly increased (P ≤ 0.0001) after 24 h of exposure to predation, compared with that of the control. The dynamic changes in the signal transductions appeared to bring about new connections in the neural networks, as suggested by the microtubule dynamics. These connections may result in improved memory and cognition abilities, and subsequently increase survivability

A method for the generation of pseudovirus particles bearing SARS coronavirus spike protein in high yields

The ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has threatened human health and the global economy. Development of additional vaccines and therapeutics is urgently required, but such development with live virus must be conducted with biosafety level 3 confinement. Pseudotyped viruses have been widely adopted for studies of virus entry and pharmaceutical development to overcome this restriction. Here we describe a modified protocol to generate vesicular stomatitis virus (VSV) pseudotyped with SARS-CoV or SARSCoV-2 spike protein in high yield. We found that a large proportion of pseudovirions produced with the conventional transient expression system lacked coronavirus spike protein at their surface as a result of inhibition of parental VSV infection by overexpression of this protein. Establishment of stable cell lines with an optimal expression level of coronavirus spike protein allowed the efficient production of progeny pseudoviruses decorated with spike protein. This improved VSV pseudovirus production method should facilitate studies of coronavirus entry and development of antiviral agents

A method for the generation of pseudovirus particles bearing SARS coronavirus spike protein in high yields

The ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has threatened human health and the global economy. Development of additional vaccines and therapeutics is urgently required, but such development with live virus must be conducted with biosafety level 3 confinement. Pseudotyped viruses have been widely adopted for studies of virus entry and pharmaceutical development to overcome this restriction. Here we describe a modified protocol to generate vesicular stomatitis virus (VSV) pseudotyped with SARS-CoV or SARS-CoV-2 spike protein in high yield. We found that a large proportion of pseudovirions produced with the conventional transient expression system lacked coronavirus spike protein at their surface as a result of inhibition of parental VSV infection by overexpression of this protein. Establishment of stable cell lines with an optimal expression level of coronavirus spike protein allowed the efficient production of progeny pseudoviruses decorated with spike protein. This improved VSV pseudovirus production method should facilitate studies of coronavirus entry and development of antiviral agents.ISSN:0386-7196ISSN:1347-370

Direct visualization of glucagon-like peptide-1 secretion by fluorescent fusion proteins

Live-cell imaging with fluorescent proteins (FPs) is a powerful tool for investigating the exocytosis processes of hormones. However, the secretion process of glucagon-like peptide-1 (GLP-1) has not been visualized by FPs, which might be because tagging FPs inhibits GLP-1 synthesis through the post-translational processing from proglucagon. Here, we have developed FP-tagged GLP-1 by inserting FPs into the middle of GLP-1 and adding the proglucagon signal peptide. Confocal imaging confirmed that GLP-1 fused to FPs with high folding efficiency showed granular structure, in which secretory vesicle markers colocalized. The fluorescence intensity of FP in the culture supernatant from cells treated with KCl or forskolin was significantly increased compared with those from untreated cells. Furthermore, FP-tagged GLP-1 enables direct visualization of stimulation-dependent exocytosis of GLP-1 at a single granule resolution with total internal reflection fluorescence microscopy. FP-tagged GLP-1 might facilitate the screening of GLP-1 secretagogues and the discovery of new antidiabetic drugs