The Infection Properties of Trionyx sinensis Hemorrhagic Syndrome Virus and the Antiviral Effect of Curcumin In Vivo.

Trionyx sinensis hemorrhagic syndrome virus (TSHSV) is an aquatic arterivirus causing a high mortality rate for T. sinensis (Chinese soft-shelled turtle), but the detailed infection properties of TSHSV are unclear, and no effective treatment is available. In this study, cell culture and histopathology were performed to elucidate the infection properties of TSHSV. Furthermore, the anti-TSHSV and immune-enhancing effects of curcumin were evaluated using survival statistics, qPCR, and tissue immunofluorescence. The results demonstrated that TSHSV could proliferate in the spleen cell line of T. sinensis, leading to cytopathic effects. TSHSV damaged the livers, kidneys, and lungs, characterized by cell disintegration and hyperemia. Curcumin at 250 mg/kg improved the survival of T. sinensis, and significantly reduced the viral load in the spleens, kidneys, and lungs. Moreover, curcumin inhibited the mRNA expression of immune-related genes, RSAD2, IFN-γ, and TNF-α (p < 0.05). In conclusion, these results imply that TSHSV is pathogenic to the spleen cell line, liver, spleen, kidney, and lung of T. sinensis. Curcumin effectively inhibits TSHSV and modulates the immune function of T. sinensis, so it holds promise as a means to prevent TSHSV.

Complete Mitochondrial Genomes of Four Pelodiscus sinensis Strains and Comparison with Other Trionychidae Species.

The Chinese soft-shelled turtle (Pelodiscus sinensis) is an important aquaculture reptile with rich nutritional and medicinal values. In recent decades, the wild resources of P. sinensis have been depleting due to natural and artificial factors. Herein, we report the complete mitochondrial genome of four P. sinensis strains, including the Japanese (RB) strain, Qingxi Huabie (HB) strain, Jiangxi (JB) strain, and Qingxi Wubie (WB) strain. The nucleotide composition within the complete mitogenomes was biased towards A + T with a variable frequency ranging from 59.28% (cox3) to 70.31% (atp8). The mitogenomes of all four strains contained 13 protein-coding genes (PCGs), 22 tRNAs, 2 rRNAs, 1 control region, and a replication origin region of the L-strand replication (OL), which was consistent with most vertebrates. Additionally, the atp8, nad4l, nad6, and nad3 genes possessed high genetic variation and can be used as potential markers for the identification of these P. sinensis strains. Additionally, all PCGs genes were evolving primarily under purifying selection. Through comparative analysis, it was revealed that most of the tRNAs were structurally different in the TψC stem, DHU stem, and acceptor stem. The length of the tandem repeats in the control region was variable in the four P. sinensis strains, ranging from 2 bp to 50 bp. Phylogenetic analysis indicated that all P. sinensis strains clustered into one branch and were closely related to other Trionychinae species. Overall, this study provides mitochondrial genome information for different P. sinensis strains to support further species identification and germplasm resource conservation.

Synthesis and Azobenzene Isomerization Investigation of Photoswitchable Glycomacrocycles.

Macrocyclic glycoazobenzenes, as an emerging class of photoswitchable chiral macrocyclic compounds, have shown interesting properties since their discovery in 2017. We have recently employed the azobenzene-ester-linked glycosyl donor-acceptor pairs to study the influence of photoisomerization on intramolecular glycosylation. To continue the investigation on the stereoselectivity aspect of glycosylation and also to enlarge the diversity of photoswitchable glycomacrocycles, we have chosen azobenzene-triazole linkers in the present study and shown that the stereoselectivity of the glycosylation is dependent on the linker length, the configuration of the azobenzene template, as well as the reaction concentration. We have optimized the reaction conditions to prepare in good yields new glycomacrocycles, which displayed excellent photochromic properties. The influence of glycosylation reagents and acidity on the stability of the Z-azobenzene substrates and cyclic glycoazobenzenes has also been investigated, demonstrating that isomerization of macrocyclic azobenzene can be tuned by photo-, thermo-, and acid stimulus.

Stereoselective synthesis and properties of glycoazobenzene macrocycles through intramolecular glycosylation.

An intramolecular glycosylation strategy was used to synthesize a series of new glycoazobenzene macrocycles with high α-selectivity and interesting chiroptical properties. The photoisomerization of an azobenzene template influences mainly the efficiency of the glycosylation.

Cyclodextrin-Based Peptide Self-Assemblies (Spds) That Enhance Peptide-Based Fluorescence Imaging and Antimicrobial Efficacy.

As a result of their high specificity for their corresponding biological targets, peptides have shown significant potential in a range of diagnostic and therapeutic applications. However, their widespread use has been limited by their minimal cell permeability and stability in biological milieus. We describe here a hepta-dicyanomethylene-4H-pyran appended ß-cyclodextrin (DCM7-ß-CD) that acts as a delivery enhancing "host" for 1-bromonaphthalene-modified peptides, as demonstrated with peptide probes P1-P4. Interaction between the fluorescent peptides P1-P3 and DCM7-ß-CD results in the hierarchical formation of unique supramolecular architectures, which we term supramolecular-peptide-dots (Spds). Each Spd (Spd-1, Spd-2, and Spd-3) was found to facilitate the intracellular delivery of the constituent fluorescent probes (P1-P3), thus allowing spatiotemporal imaging of an apoptosis biomarker (caspase-3) and mitosis. Spd-4, incorporating the antimicrobial peptide P4, was found to provide an enhanced therapeutic benefit against both Gram-positive and Gram-negative bacteria relative to P4 alone. In addition, a fluorescent Spd-4 was prepared, which revealed greater bacterial cellular uptake compared to the peptide alone (P4-FITC) in E. coli. (ATCC 25922) and S. aureus (ATCC 25923). This latter observation supports the suggestion that the Spd platform reported here has the ability to facilitate the delivery of a therapeutic peptide and provides an easy-to-implement strategy for enhancing the antimicrobial efficacy of known therapeutic peptides. The present findings thus serve to highlight a new and effective supramolecular delivery approach that is potentially generalizable to overcome limitations associated with functional peptides.

An ESIPT Probe for the Ratiometric Imaging of Peroxynitrite Facilitated by Binding to Aß-Aggregates.

A series of 3-hydroxyflavone (3-HF) ESIPT (excited-state intramolecular proton transfer) boronate-based fluorescent probes have been developed for the detection of peroxynitrite (ONOO-). The dyes are environmentally sensitive, and each probe exhibited a ratiometric response toward ONOO- in a micellar environment. The probes were used to image different aggregation states of amyloid-ß (Aß) in the presence of ONOO-. The 3-HF-OMe probe was found to produce a ratiometric response toward ONOO- when bound to Aß aggregates, resulting in a novel host-guest ensemble, which adds insight into the development of other ESIPT-based probes for the simultaneous sensing of fibrous proteins/peptides and environmental ROS/RNS.

Graphene oxide-enhanced cytoskeleton imaging and mitosis tracking.

Here we show that graphene oxide greatly enhances the imaging ability of a peptide probe that selectively targets microtubules of the cytoskeleton, thus enabling the dynamic tracking of mitosis in live cells.