Theileria annulata subtelomere-encoded variable secreted protein-TA05560 interacts with bovine RNA binding motif protein 39 (RBM39).

Theileria annulata is the only eukaryotic pathogen able to transform bovine leukocytes, including B cells, macrophages and dendritic cells. T. annulata-transformed cells exhibit several cancer-like phenotypes, such as hyperproliferation, immortalization and dissemination. Although several parasite factors involved in bovine cell transformation have been explored, the roles of subtelomere-encoded variable secreted proteins (SVSPs) of the parasite in host-cell interactions are largely unknown. In the present study, the target molecule TA05560, a member of the SVSP multigene family of T. annulata, was identified at the mRNA level during different life cycles through a quantitative real-time PCR assay, and the subcellular distribution of TA05560 was examined via confocal microscopy. The results showed that the parasite molecule TA05560 was transcribed mainly in the schizont stage of T. annulata infection, and the protein was distributed in the nucleus and cytoplasm of the parasitized cells. The potential host cell proteins that interact with TA05560 were screened using the yeast two-hybrid system, and the direct interaction between TA05560 and its prey protein, Bos taurus RNA binding motif protein 39 (RBM39) was further identified in HEK293T cells by using confocal microscopy, coimmunoprecipitation and bimolecular fluorescence complementation assays. Moreover, the interaction between TA05560 and its host protein was observed in T. annulata-infected cells via confocal microscopy. Therefore, our study is the first to show that the T. annulata-secreted TA05560 protein directly binds to both the exogenous and endogenous host cell molecule RBM39, laying the foundation for exploring host-parasite interactions and understanding the transformation mechanisms induced by T. annulata and other transforming parasites.

Quantitative Electrophysiological Evaluation of the Analgesic Efficacy of Two Lappaconitine Derivatives: A Window into Antinociceptive Drug Mechanisms.

Quantitative evaluation of analgesic efficacy improves understanding of the antinociceptive mechanisms of new analgesics and provides important guidance for their development. Lappaconitine (LA), a potent analgesic drug extracted from the root of natural Aconitum species, has been clinically used for years because of its effective analgesic and non-addictive properties. However, being limited to ethological experiments, previous studies have mainly investigated the analgesic effect of LA at the behavioral level, and the associated antinociceptive mechanisms are still unclear. In this study, electrocorticogram (ECoG) technology was used to investigate the analgesic effects of two homologous derivatives of LA, Lappaconitine hydrobromide (LAH) and Lappaconitine trifluoroacetate (LAF), on Sprague-Dawley rats subjected to nociceptive laser stimuli, and to further explore their antinociceptive mechanisms. We found that both LAH and LAF were effective in reducing pain, as manifested in the remarkable reduction of nocifensive behaviors and laser-evoked potentials (LEPs) amplitudes (N2 and P2 waves, and gamma-band oscillations), and significantly prolonged latencies of the LEP-N2/P2. These changes in LEPs reflect the similar antinociceptive mechanism of LAF and LAH, i.e., inhibition of the fast signaling pathways. In addition, there were no changes in the auditory-evoked potential (AEP-N1 component) before and after LAF or LAH treatment, suggesting that neither drug had a central anesthetic effect. Importantly, compared with LAH, LAF was superior in its effects on the magnitudes of gamma-band oscillations and the resting-state spectra, which may be associated with their differences in the octanol/water partition coefficient, degree of dissociation, toxicity, and glycine receptor regulation. Altogether, jointly applying nociceptive laser stimuli and ECoG recordings in rats, we provide solid neural evidence for the analgesic efficacy and antinociceptive mechanisms of derivatives of LA.

Hollow MnFe2O4@C@APBA Nanospheres with Size Exclusion and pH Response for Efficient Enrichment of Endogenous Glycopeptides.

Enrichment and detection of glycopeptides are an important clinical measure for the diagnosis of complex diseases. Enrichment materials play a key role in this process; they must have an effective sample-screening ability to eliminate the interference of nonglycopeptides. In this work, novel hollow MnFe2O4@C@APBA nanospheres (HMCAs) with magnetic and pH responsiveness were prepared for glycopeptide enrichment. The as-prepared composites have a suitable hollow structure and large specific surface area, and the boron hydroxyl group in their cavities can fix or disconnect the hydrophilic groups of the glycopeptides at different pH, so the glycopeptides can be adsorbed or desorbed in a controllable way. Enrichment results showed that the HMCAs exhibited an excellent enrichment performance: ultralow limit of detection (approximately 0.5 fmol µL-1), perfect size-exclusion effect (HRP/BSA, 1:800, w/w), favorable universality (HRP, IgG, and RNase B), and high binding capacity (150 mg/g). In order to verify the application of materials in practice, the HMCAs were used for the analysis of complex samples and it was found that 474 glycopeptides were identified from 210 glycoproteins in three replicate analyses of 2 µL of human serum. The results showed that the HMCAs could be used as a promising enrichment material for glycopeptide characterization in MS-based glycoproteomics and related fields.

A freeze-thawing method applied to the fabrication of 3-d curdlan/polyvinyl alcohol hydrogels as scaffolds for cell culture.

In this work, an innovative composite hydrogel composed of curdlan (CD)/polyvinyl alcohol (PVA) hydrogels with a 3-d network structure was successfully prepared by freeze-thaw processing. The presence of interactions, changes in crystallinity, and thermal behaviour were investigated by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and thermogravimetry (TGA and DTG), respectively. The morphology of the hydrogels was investigated by scanning electron microscopy (SEM). With the increase of PVA concentration, the composite hydrogel had a greater mechanical strength while remaining remarkably ductile as evinced by tensile test results. PVA content affects the swelling and water retention of CD/PVA hydrogels. The results of CCK-8 assay showed that CD/PVA hydrogels have no cytotoxic effect on the mouse fibroblast L929 cells. The AO/EB double-staining experiment further proved that the cells in the composite hydrogels had good cytocompatibility. The porous biohydrogels developed in the present work can provide an ideal cell growth environment as a scaffold. CD/PVA hydrogels highlight the value of this system for cell adhesion and proliferation, and further soft tissue engineering application.

Fabrication of a Double-Shell Ag/AgCl/G-ZnFe2O4 Nanocube with Enhanced Light Absorption and Superior Photocatalytic Antibacterial Activity.

Development of highly efficient photocatalysts is a primary goal in the photocatalysis domain among which reusable composites with a synergistic photocatalytic effect have attracted extensive interest. The ability of catalysts to capture light determines their photocatalytic effect, and porous or hollow photocatalysts are more conducive to the entry and reflection of light. The goal of this research is to develop a type of visible-light-driven, double-shell photocatalyst with high antibacterial activity and excellent cycling stability. Photocatalysts were fabricated using hollow graphitized ZnFe2O4 nanospheres (G-ZnFe2O4) as the carrier. After G-ZnFe2O4 was functionalized with a polydopamine (PDA) template layer, Ag nanoparticles (NPs) and cubic AgCl NPs were in situ generated on the surface of the PDA/G-ZnFe2O4 nanospheres successively. Then, the PDA template was removed using KOH solution, and double-shell Ag/AgCl/G-ZnFe2O4 nanocubes (referred to as DAGZNs) with excellent photocatalytic antibacterial activity were constructed. The DAGZNs showed excellent antibacterial properties against Staphylococcus aureus and Escherichia coli. The efficient synergistic photocatalytic antibacterial activity coupled with magnetic separability and recyclability of DAGZNs make them potential for practical application in water purification and environmental protection. The method of designing and synthesizing double-shell structures to enhance photocatalysis may also be extended to synthesis of other photocatalytic and optical materials.

Lappaconitine trifluoroacetate contained polyvinyl alcohol nanofibrous membranes: Characterization, biological activities and transdermal application.

Lappaconitine (LA), a potent analgesic drug extracted from the root of natural aconitum species, has been clinically used for years because of its effectiveness and non-addictive properties. However, it is mainly limited in oral and intravenous administration in the form of Lappaconitine Hydrobromide (LAH). In this work, Lappaconitine trifluoroacetate (LAF), a new derivative of LA, was successfully obtained by introducing organofluorine group to LA. This new compound had a lower toxicity (LD50 of 21.14 mg·kg-1), improved analgesic effect and longer half-life (T1/2 of 2.24 h) when compared with LAH. Moreover, in vitro transdermal permeation (Jss of 206.82 µg·cm-2·h-1) of LAF was 30.54% higher than that of LAH, means that LAF can be conveniently used for transdermal drug delivery (TDD). Therefore, drug membranes with PVA solution (10 wt%) containing LAF in various amounts were fabricated by electrospinning. The in vitro release tests confirmed that up to 81.43% of LAF in the PVA/LAF nanofibrous membranes could be released in 72 h, accompanied by significant analgesic effect when compared with the blank control group. In conclusion, the prepared LAF-loaded membrane is a novel formulation for the treatment of chronic and long-term pain.

Superparamagnetic functional C@Fe3O4 nanoflowers: development and application in acetaminophen delivery.

Fe3O4 nanoflowers (NFs) were synthesized via an aqueous solution method and coated with carbon through an in situ carbonization process. The synthesized C@Fe3O4 composites were further modified with strong oxidizing agents, forming functional C@Fe3O4 (FCF) flower-like composites with porous superstructure. Finally, the stable composites were used in the drug delivery test under ambient conditions; the amount of acetaminophen adsorption on the composite can weigh up to 25.07% in 3 h. The FCF composites show excellent porosity (165.23 m2 g-1) and magnetic properties (24.33 emu g-1). The -COOH, C[double bond, length as m-dash]O and -OH groups in the composites could be used for interaction with biomolecules that contain -OH, C[double bond, length as m-dash]O and -NH2 groups. Therefore, the composite exhibits a sustained release model, with release rates of 51% in the first 6 h and 73% in 12 h. This special character gives the composites potential to be used in magnetic bio-separation and drug/gene delivery. The findings in this study are useful for the engineering design of porous iron oxide coated with functional carbon that is used for medical delivery applications and other biomedical devices.