Dibutyltin depressed immune functions via NF-κB, and JAK/STAT signaling pathways in zebrafish (Danio rerio).

Dibutyltin (DBT) is the degradation products of TBT, which is generally considered higher toxicity than TBT in the immune system. In order to learn more about the mechanisms of immune-toxic of DBT, we exposed zebrafish (Danio rerio) to 0, 1, 10 and 100 ng/L DBT for 8 weeks. At the end of the experiment, we determined the immune parameters and immune-related genes. The results showed that with an increase in TBT dose, lysozyme activities and IgM, C3, C4 content in intestine, skin and spleen were all significantly inhibited by the DBT exposure. Fish exposed to 10 ng/L and 100 ng/L showed significantly lower lysozyme activities and IgM, C3, C4 content than those of the control group. Zebrafish exposed to 10 ng/L and 100 ng/L DBT, the mRNA transcript levels of interleukin-1ß (IL-1ß), interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor-α (TNF-α), interferon γ2 (INFγ2), nuclear factor-κB p65 (NF-kB p65), inhibitor protein-κBα (IκBα), IκB kinases ß (IKKß), Janus family of protein tyrosine kinases (JAKs) and the signal transducers and activators of transcription proteins (STATs) all increased with the DBT levels in the intestine and spleen. Those parameters showed significantly higher values in 10 ng/L and 100 ng/L than those of fish in the control group. However, no significant difference was found in IκB kinases α (IKKα) and IκB kinase γ (IKKγ) mRNA levels in the intestine and spleen. These data imply that DBT might be via suppression on IKKß/IkBa/NF-kBp65 and JAK/STAT signaling pathways to regulate the immunity of zebrafish.

Effects of Lactobacillus delbrueckii on immune response, disease resistance against Aeromonas hydrophila, antioxidant capability and growth performance of Cyprinus carpio Huanghe var.

The aim of the present study was to investigate effects of dietary Lactobacillus delbrueckii (L. delbrueckii) on immune response, disease resistance against Aeromonas hydrophila (A. hydrophila), antioxidant capability and growth performance of Cyprinus carpio Huanghe var. 450 fish (mean weight of 1.05 ± 0.03 g) were randomly distributed into five groups that fed diets containing different levels of L. delbrueckii (0, 1 × 105, 1 × 106, 1 × 107 and 1 × 108 CFU g-1) for 8 weeks. The results showed that intestinal immune parameters such as lysozyme, acid phosphatase, and myeloperoxidase activities, immunoglobulin M content, and the survival rate were improved in fish fed with 1 × 106 and 1 × 107 CFU g-1L. delbrueckii. In addition, 1 × 107 CFU g-1L. delbrueckii supplementation down-regulated mRNA levels of TNF-α, IL-8, IL-1ß and NF-κBp65, and up-regulated IL-10 and TGF-ß mRNA levels in the intestine. The survival rate was significantly (P < 0.05) higher (68.33%) in fish fed 1 × 106 CFU g-1L. delbrueckii than the control diet-fed group (40%) after challenge by A. hydrophila. Fish fed with diet containing 1 × 106 CFU g-1L. delbrueckii showed higher antioxidant enzyme activities such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), and total antioxidant capacity (T-AOC) and lower MDA concentrations than those of the control group (P < 0.05). The relative gene expression (SOD, CAT, GPX) showed the same trend with their activities. In addition, the growth performance was significantly improved in fish fed with the diet containing 1 × 106 and 1 × 107 CFU g-1L. delbrueckii (P < 0.05). These results demonstrated that dietary optimal levels of L. delbrueckii enhanced immunity, disease resistance against A. hydrophila antioxidant capability and growth performance in Cyprinus carpio Huanghe var.

Effect of four chitinase genes on the female fecundity in Sogatella furcifera (Horváth).

BACKGROUND: The white-backed planthopper (WPH), Sogatella furcifera (Horváth), is a destructive rice pest with strong reproductive capacity. To gain insights into the roles of chitinases in the reproductive process of this insect species, this study represents the first-ever endeavor to conduct an in-depth exploration into the reproductive functions of four chitinase genes. RESULTS: In this study, it was observed that four chitinase genes were expressed in female adults, with a relatively high expression level in the ovaries. SfCht2 and SfIDGF1 were highly expressed during later ovarian development. while SfENGase increased and then decreased with ovarian development. SfCht2, SfCht6-2 and SfENGase were highly expressed in fat body on the first and second days after eclosion, whereas SfIDGF1 highest on day 7. Compared with control group, Silencing four chitinase genes inhibited ovarian development and significantly shortened the oviposition period of S. furcifera, reducing egg-laying capacity but not affecting egg hatching. The detection demonstrated that the expression levels of SfVg, SfVgR and 70-90% juvenile hormone (JH) signaling pathway-related reproductive genes was significantly down-regulated. Moreover, SfCht6-2 and SfENGase significantly affected the expression levels of Target of Rapamycin (TOR) signaling pathway genes. SfENGase had the ability to impact nutrient signaling pathways and fatty acid metabolism, repressing vitellogenin synthesis and ultimately influencing ovarian development of S. furcifera. CONCLUSIONS: Overall, this study provides insight into the function of chitinases in insect fecundity and is of great significance for enriching the cognition of insect chitinase function. They will become the suitable target genes for controlling the most destructive rice planthoppers. © 2023 Society of Chemical Industry.

Wing expansion functional analysis of ion transport peptide gene in Sogatella furcifera (Horváth) (Hemiptera: Delphacidae).

Ion transport peptide (ITP), a superfamily of arthropod neuropeptides, serves a crucial role in regulating various physiological processes such as diuresis, ecdysis behavior, and wing expansion. However, the molecular characteristics, expression profile, and role of ITP in Sogatella furcifera are poorly understood. To elucidate the characteristics and biological function of ITP in S. furcifera, we employed reverse transcription-polymerase chain reaction (RT-PCR) and RNA interference (RNAi) methods. The identified SfITP gene encodes 117 amino acids. The expression of SfITP gradually increased followed the formation of 3-day-old of 5th instar nymph, peaking initially at 40 min after eclosion, and reaching another peak 24 h after eclosion, with particularly high expression levels in thorax and wing tissues. Notably, SfITP RNAi in 3rd instar nymphs of S. furcifera significantly inhibited the transcript levels of SfITP, resulting in 55% mortality and 78% wing deformity. These findings suggests that SfITP is involved in the regulation of wing expansion in S. furcifera, providing insights into the regulation of insect wing expansion and contributing to the molecular understanding of this process.

Juvenile Hormone Synthesis Pathway Gene SfIPPI Regulates Sogatella furcifera Reproduction.

The juvenile hormone (JH) is crucial for insect reproduction, and isopentenyl pyrophosphate isomerase (IPPI) is a key enzyme in the JH synthesis pathway. However, few studies have investigated how IPPI regulates insect reproduction. This study identifies and characterizes the IPPI gene (SfIPPI) from the important agricultural pest Sogatella furcifera. A phylogenetic analysis reveals a high homology of SfIPPI with the IPPI amino acid sequences of Laodelphax striatellus and Nilaparvata lugens (Stål). Furthermore, SfIPPI is expressed at various developmental stages and in various tissues of S. furcifera, and is significantly higher on the 5th day of adult emergence and in integument tissue, while lower levels are found on the 3rd day of adult emergence and in fat body and gut tissue. After silencing SfIPPI using RNA interference, the ovarian development is significantly inhibited and the fecundity is significantly reduced when compared with the control group. Additionally, SfIPPI silencing significantly decreases the expression levels of downstream JH signal transduction pathway genes (SfJHAMT, SfFAMeT, and SfKr-h1) and SfVg. Our findings are helpful in elucidating the molecular mechanism underlying the regulation of insect reproduction through genes in the JH synthesis pathway, and they provide a theoretical basis for the development of pest control treatments targeting SfIPPI.

SfDicer2 RNA Interference Inhibits Molting and Wing Expansion in Sogatella furcifera.

Endoribonuclease 2 (Dicer2) is a key nicking endonuclease involved in the small interfering RNA biosynthesis, and it plays important roles in gene regulation and antiviral immunity. The Dicer2 sequence was obtained using the transcriptomic and genomic information of Sogatella furcifera (Horváth), and the spatiotemporal characteristics and functions of molting and wing expansion regulation were studied using real-time quantitative polymerase chain reaction and RNA interference (RNAi) technology. The expression of SfDicer2 fluctuated during the nymphal stage of S. furcifera. Its expression decreased significantly over the course of molting. SfDicer2 exhibited the highest transcript level in the nymphal stage and adult fat body. After SfDicer2 was silenced, the total mortality rate was 42.69%; 18.32% of the insects died because of their inability to molt. Compared with the effects of dsGFP or water, 44.38% of the insects subjected to the silencing of SfDicer2 exhibited wing deformities after successful eclosion. After SfDicer2 RNAi, the expression of chitinase, chitin deacetylase, trehalase, chitin synthase 1, and wing expansion-related genes was significantly inhibited. These findings indicate that SfDicer2 controls molting by affecting genes associated with chitin synthesis and degradation and regulates wing expansion by altering the expression of wing expansion-related genes in S. furcifera.

[CdSe/ZnSe quantum dots via a two-phase solution system process solubilization and spectroscopic characterization].

In the present work, the CdSe/ZnSe core/shell quantum dots (QDs) were successfully transferred from organic phase to water phase via a two-phase solution system process by surface coating with amphiphilic polymer. Surface coating with amphiphilic polymer is an effective method, which can form stable soluble QDs in water. However, the conventional polymer coating method is performed in homogeneous phase, and it easily induces the aggregation of the QDs attributing to the long chain of enlace of the polymer. It is thus necessary and meaningful to develop surface coating technique for getting monodisperse coating QDs with amphiphilic polymer. In comparison with previously reported coating method, the authors' experiment process is performed in two-phase solution system, and can effectively reduces the possibility of aggregation of the QDs. The resulting hydrophilic CdSe/ZnSe core/shell QDs have long-term stability in water, and high quantum yield. The polymer coating process was affirmed by various characterizations. Fourier transform infrared spectra suggest that the octylamine modified polymer was successfully coated on the surface of the CdSe/ZnSe QDs. The transmission electron microscopy suggests that the size and shape of the QDs showed no obvious change before and after the coating process. Dynamic light scattering results indicate that the hydrophilic QDs exhibit narrow hydrodynamic size distribution with the mean hydrodynamic diameters of about 19.7 nm. The luminescence properties of the QDs were investigated with photoluminescence spectra and ultraviolet-visible absorption spectra. This polymer coating process has less effect on luminescence capability. The quantum yield decreased from 43% to 30%. Further, in order to confirm that the polymer capped QDs is biocompatible, the QDs were used for specific detection of the human IgG with fluorescence mapping. The specific molecular recognition capacity of goat anti-human IgG-modified QDs confirms that the polymer coated QDs have compatible functional chemical groups for bioconjugation and are suitable for biological applications.

[Preparation, characterization and specific biological labeling of silica coated upconversion fluorescent nanocrystals].

The authors synthesized a kind of upconversion nanocrystals NaYF4:Yb3+, Er3+ via the hydrothermal assisted homogeneous precipitation method, and then the nanocrystal was coated with silica. The SEM image demonstrated that the as-prepared samples were uniform in size distribution with ca. 25 nm before and ca. 250 nm after silica coating, respectively. The upconversion spectra and photoluminescence lifetime measurement showed that the silica shell had hardly effect on the properties of fluorescence of the NaYF4:Yb3+, Er3+ nanocrystals. At the same time, the naked eye-visible green upconversion fluorescence pattern was acquired from the as-prepared upconversion nanoparticles in the PBS buffer (2 wt%) excited by 980 nm laser at room temperature. These water-soluble nanoparticles were linked to the antibodies using the coupling reagents glutaraldehyde. The circular dichroism (CD) spectra of antibody and upconversion nanoparticles-antibody conjugates were very similar to each other, indicating that the secondary structure of antibody remained largely intact after the conjugation. Finally, antigen-antibody recognition reaction was performed on the surface of a silicon slide. The immunofluorescence in vitro indicated that the upconversion nanoparticles-antibody bioconjugates had excellent species-specific detection ability with hardly non-specific binding. Based on the present results, it is anticipated that the silica-coated upconversion nanoparticles are suitable for use as biolabeling materials.

[Effect of hole transporting materials on photoluminescence of CdSe core/shell quantum dots].

Photoluminescence quenching of colloidal CdSe core/shell quantum dots in the presence of hole transporting materials was studied by means of steady state and time resolved photoluminescence spectroscopy. With increasing hole transporting materials concentration in the CdSe core/shell quantum dot solution, the photoluminescence intensity and lifetime decreased gradually. The photoluminescence quenching of CdSe/ZnSe quantum dots with adding hole transporting material N,N'-bis(1-naphthyl)-N, N'-diphenyl-1,1 '-biphenyl-4, 4'-diamine (NPB) is more efficient than N,N'-diphenyl-N, N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD). And compared with CdSe core/shell quantum dots with ZnSe shell, the ZnS shell is an effective one on the surface of CdSe quantum dots for reducing photoluminescence quenching efficiency when interacting with hole transporting material TPD. Based on the analysis, there are two pathways in the photoluminescence quenching process: static quenching and dynamic quenching. The static quenching results from the decrease in the number of the emitting centers, and the dynamic quenching is caused by the hole transfer from quantum dots to hole transporting materials molecules. The efficiency of the photoluminescence quenching in CdSe core/shell quantum dots is strongly dependent on the structure of the shells and the HOMO levels of the hole transporting materials. The results are important for understanding the nature of quantum dots surface and the interaction of quantum dots and hole transporting materials.

[Study of applying fluorescence spectrum imaging to quantitative assay of proteins in bio-chip].

In the present work, the amount and the activity of the goat anti-human IgG, to bind the human IgG labelled with fluorescein isothiocyanate (FITC), immobilized on silicon surfaces modified with APTES and APTES-Glu, respectively, were studied using the fluorescence spectrum imaging (FSI), the results of which were compared with that of ellipsometry. It is shown that the amount of the human IgG labeled with FITC on APTES-Glu measured using FSI is 2.8 times higher than that on APTES, which is nearly coincident with the 2.2 times obtained using ellipsometry, showing that the activity of the goat anti-human IgG on APTES-Glu is higher than that on APTES. It is reasoned that the FSI is used in the fluorescence immunoassay the for measurement of quasi-quantification or quantification.

[Effects of penetration enhancers on percutaneous permeability of geniposide in Xiao'er Ninhuang tuire cataplasms].

OBJECTIVE: To investigate the different permeation enhancers on the transdermal permeation of Xiao'er Niuhuang tuire cataplasms (XNTC). METHOD: Using improved franz-type diffusion cell with excised rat skin in vitro as the transdermal barrier, the content of permeated geniposide was determined by HPLC to study the kinetic parameters such as cumulative permeation quantity and permeation rate. RESULT: The result showed that the process of penetrating of geniposide in XNTC through skin could be in accordance with zero-rade releasing equation and XNTC was stable during the course of experiment. CONCLUSION: 5% Propylene glycol (PG)-azone (2:3) has the best permeation-enhancing effect, and the results provided a primary basis for the future research on Xiao'er Niuhuang tuire cataplasms.

[Surface enhanced Raman spectroscopic study on the gold-labeled protein self-assembled surface].

The human IgG molecules were labeled with 13 nm gold nanoparticles and the complex of the gold-labeled human IgG molecules was immobilized on a silicon surface modified by 3-aminopropyltriethoxysilane and glutaraldehyde. The method increases not only the tightness but also the surface coverage for immobilization of the complex and retains protein configuration well on the silicon surface. The self-assembled complex surface was observed by AFM. The complex aggregated on the silicon surface and the "island" monolayer of the complex was obtained. Meanwhile the SERS spectrum of the complex self-assembled "island" monolayer on silicon surface was presented. In the present paper, the gold labeled human IgG molecules were self-assembled on the silicon surface, SERS spectra of protein were obtained and as SERS active substrates were provided for the study of the protein molecules.