Human keratinocyte growth factor-1 (hKGF-1), a member of the fibroblast growth factor (FGF) family, plays crucial roles in organ development, cell proliferation, wound healing, and tissue repair, representing one of the most effective and specific growth factors for skin repair. However, obtaining recombinant hKGF-1 remains challenging due to its universally low expression efficiency in vitro. This study employs the Bombyx mori baculovirus expression system to establish a technological platform that utilizes the economically important insect Bombyx mori as a bioreactor for high-efficiency and low-cost expression and production of recombinant human keratinocyte growth factor 1 (hKGF-1) protein, ultimately achieving high-level expression of hKGF-1 in Bombyx mori ovary cell line (BmN). In this study, we optimized the hKGF-1 sequence based on the codon preference of baculovirus. By fusing hKGF-1 with polyhedrin (highly expressed in this system) and adding extra promoters and enhancers, we significantly improved the expreesion level of hKGF-1 in Bombyx mori cells. The results demonstrated that the aforementioned strategies significantly enhanced the expression level of hKGF-1 in Bombyx mori cells. SDS-PAGE and Western blotting results revealed that the highest hKGF-1 expression (accounting for 8.7% of total cellular protein) was achieved when the Polh promoter was combined in tandem with the P6.9 promoter and hKGF-1 was fused with a 15-residue polyhedrin fragment for co-expression. The optimal harvest time was determined to be 120 h post transfection. This study achieved the efficient expression of hKGF-1 in Bombyx mori cells, establishing an ideal technological platform for the industrial utilization of recombinant hKGF-1. The developed methodology not only provides valuable technical references for the production of other growth factors and complex proteins, but also demonstrates significant implications for employing silkworms as bioreactors for recombinant human protein expression.
Bombyx/metabolism* ; Animals ; Baculoviridae/metabolism* ; Humans ; Fibroblast Growth Factor 7/biosynthesis* ; Recombinant Proteins/genetics* ; Cell Line ; Genetic Vectors/genetics*

Bombyx mori nucleopolyhedrovirus (BmNPV) is extremely harmful to the silk industry. The polyhedrin, which encodes the polyhedrin (Polh), can be expressed at ultra-high levels and form occlusion bodies in the nucleus, embedding the progeny virus within it. However, the detailed mechanism by which polyhedrin is transported into the host cell nucleus remains unknown. Clarifying the nuclear import mechanisms of viral proteins can help us develop better prevention and treatment measures against baculoviruses. This study employed molecular cloning, co-immunoprecipitation, and immunofluorescence to analyze in detail the expression pattern of the highly expressed polyhedrin in the very late stage of the virus, and further revealed that the host protein importin α participates in the nuclear import of polyhedrin through protein interactions. This study provides a reference for further elucidating the nuclear import mechanisms of the baculovirus proteins including polyhedrin that can enter the nucleus.
Nucleopolyhedroviruses/metabolism* ; Active Transport, Cell Nucleus ; Animals ; Bombyx/virology* ; alpha Karyopherins/metabolism* ; Cell Nucleus/metabolism* ; Viral Structural Proteins/metabolism* ; Occlusion Body Matrix Proteins

Human epidermal growth factor (hEGF) can be applied in the treatment of surgical trauma (burns, scalds), tissue repair, skin moisturizing, beauty, skincare, etc. However, the low expression and high cost limit the application of hEGF. In order to improve the expression level of hEGF and reduce the production cost, considering the high expression of polyhedrin, this study fused a partial sequence of polyhedrin with hEGF and expressed the fused sequence by using a silkworm baculovirus expression vector system. In view of the small molecular weight of hEGF, we connected hEGF genes in series and optimized the codons to construct multiple fusion expression vectors by fusing different partial sequences of polyhedrin at the N-terminus. The results showed that through the above strategy, the protein expression level of hEGF was significantly increased. The expression vector containing three concatenated hEGF genes with optimized codons and fused with the sequence encoding 25 or 35 residues at the N-terminus of polyhedrin showed the highest expression level.
Humans ; Epidermal Growth Factor/biosynthesis* ; Genetic Vectors/genetics* ; Recombinant Fusion Proteins/biosynthesis* ; Animals ; Bombyx/metabolism* ; Occlusion Body Matrix Proteins/genetics* ; Nucleopolyhedroviruses/genetics* ; Amino Acid Sequence

Objective: To explore the relationship between extracellular enzymes activity and virulence of Candida glabrata clinical isolates based on the infection model of Galleria mellonella larvae. Methods: Using experimental research methods, 71 strains of non-repetitive Candida glabrata were collected from Qinghai Provincial People's Hospital from June 2021 to January 2022. Bovine serum protein agar medium, egg yolk agar medium, sheep blood agar medium, Tween-80 agar medium and triglyceride agar medium were used to detect the aspartyl protease activity, phospholipase activity, hemolysis activity, esterase activity and lipase activity of Candida glabrata. Median lethal concentration (LC₅₀) was calculated by using 1.25×10⁸ CFU/ml,2.50×10⁸ CFU/ml,3.75×10⁸ CFU/ml,5.00×10⁸ CFU/ml suspension of Candida glabrata ATCC2001 to infect Galleria mellonella larvae. Histopathological and etiological analysis was performed to determine whether the infection model was successfully established. The clinical isolates of Candida glabrata were configured to infect Galleria mellonella larvae with LC₅₀ concentration to detect the pathogenicity of Galleria mellonella larvae.Spearman test or Pearson test were used to analyze the correlation between the extracellular enzyme activity of Candida glabrata clinical isolates and the pathogenicity of Galleria mellonella larvae. Results: 71 strains of Candida glabrata isolated clinically were detected to have low hemolytic activity after 2 days of culture. Aspartyl protease was detected after 4 days of culture, among which 7 strains (9.86%), 19 strains (26.76%) and 45 strains (63.38%) showed low, medium and high aspartyl protease activity. After 7 days of culture, 71 strains did not detect phospholipase, esterase and lipase activities. Candida glabrata on Galleria mellonella larvae of LC₅₀=2.5×10⁸ CFU/ml Fungal spore were found in the intestinal tissue pathological section of Galleria mellonella larvae in the experimental group, and Candida glabrata was identified by the microbial Mass Spectrometry after culture, while no fungi were found in the pathological section and culture of the control group. Spearman test shows that, there was a linear positive correlation between aspartyl protease activity and the survival rate of Galleria mellonella larvae (r = 0.73, P<0.01), the difference was statistically significant.Pearson test shows that, there was no significant linear relationship between hemolytic activity and survival rate of Galleria mellonella larvae (r = 0.16, P = 0.34), the difference was not statistically significant. Conclusion: The clinical isolates of Candida glabrata in this study had aspartyl protease activity and low hemolytic activity, but no phospholipase, esterase and lipase activity. The activity of aspartyl aspartyl protease of Candida glabrata was positively correlated with the pathogenicity of Galleria mellonella larvae.
Animals ; Sheep ; Larva/microbiology* ; Virulence ; Candida glabrata ; Agar ; Moths/microbiology* ; Esterases ; Aspartic Acid Proteases ; Lipase

This study aims to investigate the effect of Bombyx Batryticatus extract(BBE) on behaviors of rats with global cerebral ischemia reperfusion(I/R) and the underlying mechanism. The automatic coagulometer was used to detect the four indices of human plasma coagulation after BBE intervention for quality control of the extract. Sixty 4-week-old male SD rats were randomized into sham operation group(equivalent volume of normal saline, ip), model group(equivalent volume of normal saline, ip), positive drug group(900 IU·kg~(-1) heparin, ip), and low-, medium-, and high-dose BBE groups(0.45, 0.9, and 1.8 mg·g~(-1)·d~(-1) BBE, ip). Except the sham operation group, rats were subjected to bilateral common carotid artery occlusion followed by reperfusion(BCCAO/R) to induce I/R. The administration lasted 7 days for all the groups. The behaviors of rats were examined by beam balance test(BBT). Morphological changes of brain tissue were observed based on hematoxylin-eosin(HE) staining. Immunofluorescence method was used to detect common leukocyte antigen(CD45), leukocyte differentiation antigen(CD11b), and arginase-1(Arg-1) in cerebral cortex(CC). The protein expression of interleukin-1β(IL-1β), interleukin-4(IL-4), interleukin-6(IL-6), and interleukin-10(IL-10) was detected by enzyme-linked immunosorbent assay(ELISA). The non-targeted metabonomics was employed to detect the levels of metabolites in plasma and CC of rats after BBE intervention. The results of quality control showed that the BBE prolonged the activated partial thromboplastin time(APTT), prothrombin time(PT), and thrombin time(TT) of human plasma, which was similar to the anticoagulation effect of BBE obtained previously. The results of behavioral test showed that the BBT score of the model group increased compared with that of the sham operation group. Compared with the model group, BBE reduced the BBT score. As for the histomorphological examination, compared with the sham operation group, the model group showed morphological changes of a lot of nerve cells in CC. The nerve cells with abnormal morphology in CC decreased after the intervention of BBE compared with those in the model group. Compared with the sham operation group, the model group had high average fluorescence intensity of CD45 and CD11b in the CC. The average fluorescence intensity of CD11b decreased and the average fluorescence intensity of Arg-1 increased in CC in the low-dose BBE group compared with those in the model group. The average fluorescence intensity of CD45 and CD11b decreased and the average fluorescence intensity of Arg-1 increased in medium-and high-dose BBE groups compared with those in the model group. The expression of IL-1β and IL-6 was higher and the expression of IL-4 and IL-10 was lower in the model group than in the sham operation group. The expression of IL-1β and IL-6 was lower and the expression of IL-4 and IL-10 was higher in the low-dose, medium-dose, and high-dose BBE groups than in the model group. The results of non-targeted metabonomics showed that 809 metabolites of BBE were identified, and 57 new metabolites in rat plasma and 45 new metabolites in rat CC were found. BBE with anticoagulant effect can improve the behaviors of I/R rats, and the mechanism is that it promotes the polarization of microglia to M2 type, enhances its anti-inflammatory and phagocytic functions, and thus alleviates the damage of nerve cells in CC.
Humans ; Rats ; Male ; Animals ; Interleukin-10 ; Rats, Sprague-Dawley ; Interleukin-4/metabolism* ; Bombyx ; Interleukin-6/metabolism* ; Microglia/metabolism* ; Saline Solution/metabolism* ; Reperfusion Injury/metabolism* ; Brain Ischemia/metabolism* ; Cerebral Infarction ; Reperfusion ; Neurons

Deacetylation of chitin is closely related to insect development and metamorphosis. Chitin deacetylase (CDA) is a key enzyme in the process. However, to date, the CDAs of Bombyx mori (BmCDAs), which is a model Lepidopteran insect, were not well studied. In order to better understand the role of BmCDAs in the metamorphosis and development of silkworm, the BmCDA2 which is highly expressed in epidermis was selected to study by bioinformatics methods, protein expression purification and immunofluorescence localization. The results showed that the two mRNA splicing forms of BmCDA2, namely BmCDA2a and BmCDA2b, were highly expressed in the larval and pupal epidermis, respectively. Both genes had chitin deacetylase catalytic domain, chitin binding domain and low density lipoprotein receptor domain. Western blot showed that the BmCDA2 protein was mainly expressed in the epidermis. Moreover, fluorescence immunolocalization showed that BmCDA2 protein gradually increased and accumulated with the formation of larval new epidermis, suggesting that BmCDA2 may be involved in the formation or assembly of larval new epidermis. The results increased our understandings to the biological functions of BmCDAs, and may facilitate the CDA study of other insects.
Animals ; Bombyx/metabolism* ; Metamorphosis, Biological/genetics* ; Larva/metabolism* ; Gene Expression ; Insect Proteins/metabolism* ; Chitin

c-Myc protein encoded by c-Myc (cellular-myelocytomatosis viral oncogene) gene regulates the related gene expression through the Wnt/β-catenin signaling pathway, and has received extensive attention in recent years. The purpose of this study was to express Helicoverpa armigera c-Myc gene (Ha-c-Myc) by using prokaryotic expression system, prepare the polyclonal antibody, examine the spatio-temporal expression profile of Ha-c-Myc, and investigate the possible function of Ha-c-Myc in regulating H. armigera sterol carrier protein-2 (SCP-2) gene expression. The Ha-c-Myc gene was amplified by PCR and cloned into a prokaryotic expression plasmid pET-32a(+). The recombinant plasmid pET-32a-Ha-c-Myc was transformed into Escherichia coli BL21. IPTG was used to induce the expression of the recombinant protein. Protein was purified by Ni²⁺-NTA column and used to immunize New Zealand rabbits for preparing the polyclonal antibody. The Ha-c-Myc expression levels in different developmental stages (egg, larva, prepupa, pupa, and adult) of H. armigera and different tissues (midgut, fat body, head, and epidermis) of the prepupa were determined by real-time quantitative reverse transcription PCR (qRT-PCR). Ha-c-Myc siRNA was synthesized and transfected into H. armigera Ha cells. The relative mRNA levels of Ha-c-Myc and HaSCP-2 in Ha cells were detected by qRT-PCR. Results showed that the pET-32a-Ha-c-Myc recombinant plasmid was constructed. The soluble Ha-c-Myc protein of about 65 kDa was expressed in E. coli. The polyclonal antibody was prepared. Western blotting analysis suggested that the antibody had high specificity. Enzyme linked immunosorbent assay (ELISA) showed that the titer of the antibody was high. Ha-c-Myc gene expressed at all developmental stages, with high levels in the early and late instars of larva, and the prepupal stage. Tissue expression profiles revealed that Ha-c-Myc expressed in various tissues of prepupa, with high expression level in the midgut, but low levels in the epidermis and fat body. RNAi results showed that the knockdown of Ha-c-Myc expression significantly affected transcription of HaSCP-2, leading to a 50% reduction in HaSCP-2 mRNA expression level. In conclusion, the Ha-c-Myc was expressed through a prokaryotic expression system, and the polyclonal anti-Ha-c-Myc antibody was obtained. Ha-c-Myc may promote the expression of HaSCP-2 and play an important role in the lipid metabolism of H. armigera. These results may facilitate further study on the potential role and function mechanism of Ha-c-Myc in H. armigera and provide experimental data for exploring new targets of green pesticides.
Animals ; Rabbits ; Escherichia coli/metabolism* ; Enzyme-Linked Immunosorbent Assay ; Moths/genetics* ; Blotting, Western ; Larva/genetics* ; Isoantibodies/metabolism* ; Antibody Specificity

Starting with the relationship between mulberry leaves and silkworm droppings as food and metabolites, this study systematically compared the chemical components, screened out differential components, and quantitatively analyzed the main differential components based on ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS) and UPLC-Q-TRAP-MS combined with principal component analysis(PCA) and orthogonal partial least squares-discriminant analysis(OPLS-DA). Moreover, the in vitro enzymatic transformation of the representative differential components was studied. The results showed that(1) 95 components were identified from mulberry leaves and silkworm droppings, among which 27 components only exist in mulberry leaves and 8 components in silkworm droppings. The main differential components were flavonoid glycosides and chlorogenic acids.(2) Nineteen components with significant difference were quantitatively analyzed, and the components with significant differences and high content were neochlorogenic acid, chlorogenic acid, and rutin.(3) The crude protease in the mid-gut of silkworm significantly metabolized neochlorogenic acid and chlorogenic acid, which may be an important reason for the efficacy change in mulberry leaves and silkworm droppings. This study lays a scientific foundation for the development, utilization, and quality control of mulberry leaves and silkworm droppings. It provides references for clarifying the possible material basis and mechanism of the pungent-cool and dispersing nature of mulberry leaves transforming into the pungent-warm and dampness-resolving nature of silkworm droppings, and offers a new idea for the study of nature-effect transformation mechanism of traditional Chinese medicine.
Animals ; Bombyx ; Morus/chemistry* ; Chlorogenic Acid/analysis* ; Gas Chromatography-Mass Spectrometry ; Chromatography, High Pressure Liquid/methods* ; Plant Leaves/chemistry*

Bombyx Batryticatus is a precious traditional Chinese animal drug commonly used in clinical practice in China, which has the effects of extinguishing wind, stopping convulsions, dispelling wind, relieving pain, resolving phlegm, and dissipating mass. The processing of Bombyx Batryticatus has a long history. As early as in the Liu Song period of the Southern and Northern Dynasties, there was a record of the processing of Bombyx Batryticatus with rice swill. In addition to the processing with bran, honey bran, and ginger juice, which are still used today, there are also processing methods such as rendering, flour processing, wine processing, salt processing, oil processing, charcoal, and red dates processing in ancient times. After processing, the fishy smell of Bombyx Batryticatus can be removed, and avoid nausea and vomiting caused by the direct taking. Furthermore, processing can also facilitate the removal of surface hairs and toxicity reduction, making the medicinal material crispy and easy to crush. Previous studies have shown that the main chemical constituents of Bombyx Batryticatus include protein polypeptides, sterols, and flavonoids, with anticonvulsant, anticoagulation, antithrombotic, anti-cancer, hypnotic, hypoglycemic, and other pharmacological effects. This paper reviewed the processing historical evolution, chemical constituents, and pharmacological effects of Bombyx Batryticatus to lay a foundation for the research on the processing mechanism, quality control, and active core substances of Bombyx Batryticatus.
Animals ; Bombyx ; China ; Evolution, Chemical ; Flavonoids ; Fruit

The aim of this study was to prepare tandem multimeric proteins of BmSPI38, a silkworm protease inhibitor, with better structural homogeneity, higher activity and stronger antifungal ability by protein engineering. The tandem multimeric proteins of BmSPI38 were prepared by prokaryotic expression technology. The effects of tandem multimerization on the structural homogeneity, inhibitory activity and antifungal ability of BmSPI38 were explored by in-gel activity staining of protease inhibitor, protease inhibition assays and fungal growth inhibition experiments. Activity staining showed that the tandem expression based on the peptide flexible linker greatly improved the structural homogeneity of BmSPI38 protein. Protease inhibition experiments showed that the tandem trimerization and tetramerization based on the linker improved the inhibitory ability of BmSPI38 to microbial proteases. Conidial germination assays showed that His₆-SPI38L-tetramer had stronger inhibition on conidial germination of Beauveria bassiana than that of His₆-SPI38-monomer. Fungal growth inhibition assay showed that the inhibitory ability of BmSPI38 against Saccharomyces cerevisiae and Candida albicans could be enhanced by tandem multimerization. The present study successfully achieved the heterologous active expression of the silkworm protease inhibitor BmSPI38 in Escherichia coli, and confirmed that the structural homogeneity and antifungal ability of BmSPI38 could be enhanced by tandem multimerization. This study provides important theoretical basis and new strategies for cultivating antifungal transgenic silkworm. Moreover, it may promote the exogenous production of BmSPI38 and its application in the medical field.
Animals ; Antifungal Agents/pharmacology* ; Escherichia coli/metabolism* ; Proteins/metabolism* ; Protease Inhibitors/chemistry* ; Bombyx/chemistry* ; Saccharomyces cerevisiae/metabolism* ; Peptide Hydrolases