Biomedical subjects

Ziniu Yu

Publications and source records attributed to Ziniu Yu.

At least 19 recordsLinked to original sources

PubMed2025

Multi-omics reveals an ecdysone-activated Eip75B-FABP signaling axis coordinating nutrient metabolism for development in Hermetia illucens.

INTRODUCTION: Efficient nutrient storage is essential for insect development and energy homeostasis; however, the mechanisms coordinating nutrient allocation during ontogeny are not well understood. Elucidating these systems may yield valuable insights to insect metabolic adaptation. OBJECTIVES: This study aimed to identify regulatory modules governing nutrient metabolism in insects, focusing on hormonal and metabolic interplay. METHODS: Multi-omics profiling (proteomics, phosphoproteomics, and transcriptomics) was conducted throughout the life cycle, from egg to adult, to identify metabolic regulators. RNAi was utilized for gene knockdown, followed by qRT-PCR and mitochondrial DNA quantification to evaluate knockdown efficiency and its metabolic implications. Assessments of nutrient metabolism were performed using assays for triglycerides, crude protein, and fatty acid synthase. EMSA and BODIPY staining examined transcriptional regulation and lipid droplet dynamics. RESULTS: Utilizing an integrative multi-omics approach, this study elucidates the temporal metabolic regulators in insects. A conserved regulatory module was identified in which the PPAR homolog, ecdysone-induced protein 75B (Eip75B), functions as a transcriptional activator of fatty acid binding protein (FABP), sustaining lipid metabolic homeostasis during the larval stage. PPARγ modulators (rosiglitazone and GW9662) alter lipid accumulation, along with the expression of Eip75B and FABP, which was measured by qRT-PCR. Furthermore, the deficiency of FABP may reprogram metabolic pathways by inhibiting lipid storage and promoting mitochondrial β-oxidation, as supported by increased mitochondrial DNA copy number, as well as enhancing protein synthesis. This metabolic change could be modulated by ecdysone signaling, as hormonal supplementation effectively rescued the lipid loss phenotype. Our results establish the ecdysone-Eip75B-FABP signaling axis as a central regulatory module that integrates hormonal and nutrient-sensing signals to control insect nutritional metabolism. CONCLUSION: The ecdysone-Eip75B-FABP axis integrates hormonal and nutrient signals to regulate metabolic plasticity, underscoring a universal strategy for developmental energy allocation. The data also offer potential implications for research on metabolic disorders and bioenergy applications.

Animals↗

PubMed2007

Identification of three Zwittermicin A biosynthesis-related genes from Bacillus thuringiensis subsp. kurstaki strain YBT-1520.

Zwittermicin A (ZwA) is a novel, broad-spectrum linear aminopolyol antibiotic produced by some Bacillus cereus and Bacillus thuringiensis. However, only part of its biosynthesis cluster has been identified and characterized from B. cereus UW85. To better understand the biosynthesis cluster of ZwA, a bacterial artificial chromosome (BAC) library of B. thuringiensis subsp. kurstaki strain YBT-1520, a ZwA-producing strain, was constructed. Two BAC clones, 1F8 and 5E2, were obtained by PCR, which overlap the known ZwA biosynthesis cluster of B. cereus UW85. This ZwA biosynthesis cluster is at least 38.6 kb and is located on the chromosome, instead of the plasmid. Partial DNA sequencing revealed both BAC clones carry three new ZwA biosynthesis-related genes, zwa6, zwa5A and zwa5B, which were found at the corresponding location of B. cereus UW85. Putative amino acid sequences of these genes shown that ZWA6 is homologous to a typical carbamoyltransferase from Streptomyces avermitilis, while ZWA5A and ZWA5B are homologs of cysteine synthetase and ornithine cyclodeaminase which jointly synthesize 2,3-diaminopropionate in the viomycin biosynthesis pathway, respectively. The identification of these three genes further supports the hypothesized ZwA biosynthesis pathway.

Bacillus thuringiensis↗

PubMed2007

Fusion of the genes for AHL-lactonase and S-layer protein in Bacillus thuringiensis increases its ability to inhibit soft rot caused by Erwinia carotovora.

Two genes, ctc and ctc2, responsible for surface layer (S-layer) protein synthesis in Bacillus thuringiensis CTC, were mutated and resulted in B. thuringiensis Tr5. To synthesize and express the N-acyl-homoserine lactonase (AHL-lactonase) in the extracellular space of B. thuringiensis, the aiiA ( 4Q7 ) gene (an AHL-lactonase gene from B. thuringiensis 4Q7), which confers the ability to inhibit plant soft rot disease in B. thuringiensis 4Q7, was fused with the upstream sequence of the ctc gene, which in turn is essential for S-layer protein secretion and anchoring on the cell surface. The resulting fusion gene, slh-aiiA, was expressed in B. thuringiensis Tr5 to avoid competition for the extracellular space with the native S-layer protein. Our results indicate that B. thuringiensis Tr5 containing the fusion gene slh-aiiA displayed high extracellular AHL-degrading activity. When compared with wild-type B. thuringiensis strains, the ability of the constructed strain to inhibit soft rot disease caused by Erwinia carotovora SCG1 was markedly increased. These findings provide evidence for a significant advance in our ability to inhibit soft rot disease caused by E. carotovora.

Antibiosis↗

PubMed2006

Molecular characterization of a DNA fragment harboring the replicon of pBMB165 from Bacillus thuringiensis subsp. tenebrionis.

BACKGROUND: Bacillus thuringiensis belongs to the Bacillus cereus sensu lato group of Gram-positive and spore-forming bacteria. Most isolates of B. thuringiensis can bear many endogenous plasmids, and the number and size of these plasmids can vary widely among strains or subspecies. As far as we know, the replicon of the plasmid pBMB165 is the first instance of a plasmid replicon being isolated from subsp. tenebrionis and characterized. RESULTS: A 20 kb DNA fragment containing a plasmid replicon was isolated from B. thuringiensis subsp. tenebrionis YBT-1765 and characterized. By Southern blot analysis, this replicon region was determined to be located on pBMB165, the largest detected plasmid (about 82 kb) of strain YBT-1765. Deletion analysis revealed that a replication initiation protein (Rep165), an origin of replication (ori165) and an iteron region were required for replication. In addition, two overlapping ORFs (orf6 and orf10) were found to be involved in stability control of plasmid. Sequence comparison showed that the replicon of pBMB165 was homologous to the pAMbeta1 family replicons, indicating that the pBMB165 replicon belongs to this family. The presence of five transposable elements or remnants thereof in close proximity to and within the replicon control region led us to speculate that genetic exchange and recombination are potentially responsible for the divergence among the replicons of this plasmid family. CONCLUSION: The replication and stability features of the pBMB165 from B. thuringiensis subsp. tenebrionis YBT-1765 were identified. Of particular interest is the homology and divergence shared between the pBMB165 replicon and other pAMbeta1 family replicons.

Bacillus thuringiensis↗

PubMed2006

Restraining Erwinia virulence by expression of N-acyl homoserine lactonase gene pro3A-aiiA in Bacillus thuringiensis subsp leesis.

To widen the biological control function of a genetically modified Bacillus thuringiensis subsp leesis strain BMB-005, an acyl homoserine lactonase (AHL lactonase) gene aiiA transcribed by the promoter of insecticidal crystal protein coding gene cry3A, was transformed into strain BMB-005. The amount of AHL lactonase protein produced by transformant BMB821A was 2.4-fold more than that produced by BMB-005. AHL-degradation assay showed that transformant BMB821A could degrade more AHLs molecules than the original strain BMB-005. The result of Erwinia carotovora pathogenicity test showed that the parental strain BMB-005 had no restraint of Erwinia infection, but the transformants exhibited strong restraint of E. carotovora infection on potato slices and cactus stems. Insecticidal bioassay against lepidopteran Spodoptera exigua showed that both strain BMB-005 and transformant BMB821A were toxic to S. exigua. The toxicity of transformant BMB821A (LC(50) was 3.8) was a little attenuated comparing with the toxicity of the original strain BMB-005 (LC(50) was 2.9). The B. thuringiensis strain BMB-005 has high toxicity against Helicoverpa armigera, Plutella xylostella, and S. exigua. This work provided new strategy for developing genetically engineered multi-functional B. thuringiensis strain that possesses insecticidal activity together with restraint of bacterial pathogenicity.

Animals↗

PubMed2006

Optimal production of poly-gamma-glutamic acid by metabolically engineered Escherichia coli.

Metabolically-engineered Escherichia coli strains were developed by cloning poly-gamma-glutamic acid (gamma-PGA) biosynthesis genes, consisting of pgsB, pgsC and pgsA, from Bacillus subtilis The metabolic and regulatory pathways of gamma-PGA biosynthesis in E. coli were analyzed by DNA microarray. The inducible trc promoter and a constitutive promoter (P(HCE)) derived from the D-amino acid aminotransferase (D-AAT) gene of Geobacillus toebii were employed. The constitutive HCE promoter was more efficient than inducible trc promoter for the expression of gamma-PGA biosynthesis genes. DNA microarray analysis showed that the expression levels of several NtrC family genes, glnA, glnK, glnG, yhdX, yhdY, yhdZ, amtB, nac, argT and cbl were up-regulated and sucA, B, C, D genes were down-regulated. When (NH(4))(2)SO(4 )was added at 40 g/l into the feeding solution, the final gamma-PGA concentration reached 3.7 g/l in the fed-batch culture of recombinant E. coli/pCOpgs.

Bacterial Proteins↗

PubMed2006

Expressed proteome analysis of human hepatocellular carcinoma in nude mice (LCI-D20) with high metastasis potential.

We report for the first time an expressed proteome for human hepatocellular carcinoma (HCC) in nude mice model. Most cases of human liver cancer are HCC with highly metastatic ability. Therefore, the early prediction or diagnosis and effective treatment are the key points of research. We have previously successfully established a human HCC nude mice model (LCI-D20) with high metastasis potential. To understand better the tumor biology of HCC it is worth to explore the relativity of all expressed protein profiles in the LCI-D20 HCC nude mice model. With advanced proteomics technologies, we have carried out a proteomic analysis with following stages: protein sample preparation of cancer tissue, including total cellular extraction and sequential fractionation, 2-DE and 2-D LC separation, ESI/MALDI-MS/MS identification, as well as data-dependent bioinformatics. The identified proteins were classified bioinformatically respective to their function, biological process and intracellular localization. Some important proteins found in HCC, e.g. metabolism enzymes, proteins regulating cell motility, signaling proteins, and heat shock proteins, are discussed in terms of their metastasis.

Animals↗

PubMed2005

The effect of microwave irradiation on enzymatic hydrolysis of rice straw.

A series of experiments involving microwave irradiation were carried out to evaluate the effect of microwave irradiation on enzymatic hydrolysis of rice straw. Compared with microwave irradiation free hydrolysis, rice straw pretreated by combining microwave irradiation with alkali could increase the initial hydrolysis rate but the hydrolysis yield remained unchanged. When the enzyme solution was treated by microwave irradiation, the initial hydrolysis rate increased slightly, but the yield was decreased remarkably. Its optimal hydrolysis conditions were temperature (45 degrees C), pH (4.8) and enzyme loading (20 mg g(-1) substrate), which was determined by an orthogonal experiment. When intermittent microwave irradiation was used, initial hydrolysis rate was greatly accelerated but the yield was decreased slightly. Its optimal hydrolysis conditions were temperature (50 degrees C), pH (4.8) and enzyme loading (20 mg g(-1) substrate), which was determined by another orthogonal experiment.

Carbohydrates↗

PubMed2005

Improved production of insecticidal proteins in Bacillus thuringiensis strains carrying an additional cry1C gene in its chromosome.

A cryIC gene, whose product is active against Spodoptera exigua, was introduced into wildtype Bacillus thuringiensis kurstaki strain YBT1520 using an integrative and thermosensitive vector, pBMB-FLCE, which was developed based on B. thuringiensis transposon Tn4430 harboring a tnpI-tnpA gene. With the mediation of TnpI-TnpA, the cry1C gene was integrated into the chromosome of the host strain. To prevent secondary integration, the integrative vector was eliminated by moving recombinant cultures to 46 degrees C for generations. Two integrative recombinant B. thuringiensis strains BMB1520-E and BMB1520-F were obtained. In recombinant BMB1520-F, the cry1C gene was expressed stably at a significant level and did not reduce the expression of endogenous crystal protein genes. Bioassay results indicated that BMB1520-E and BMB1520-F showed a higher level of activity against S. exigua third-instar larvae than did their parent strains, in addition to the high toxicity to Plutella xylostella third-instar later larvae.

Animals↗

PubMed2005

Broadening the insecticidal spectrum of Lepidoptera-specific Bacillus thuringiensis strains by chromosomal integration of cry3A.

A TnpI-TnpIA-mediated and thermosensitive recombination system was developed to construct genetically modified Bacillus thuringiensis strains encoding a crystal protein particularly active against Coleopteran species. Based on B. thuringiensis transposon Tn4430, an integrative vector, pBMB-R14E, was constructed, by which the cry3A delta-endotoxin gene highly toxic to Lepidoptera was delivered into a wildtype B. thuringiensis subsp. kurstaki strain YBT1520. The cry3A gene was integrated into the chromosome of the host strain. Then the integrative vector was eliminated by moving recombinant cultures to 46 degrees C. Two recombinant B. thuringiensis strains, BMB1520-S and BMB1520-T, were obtained. In recombinant strains, the cry3A gene was stably expressed in measurable amounts and did not reduce the expression of endogenous crystal protein genes. Bioassay results showed that BMB1520-S and BMB1520-T, in addition to the activity against lepidopteran Plutella xylostella third-instar larvae present in the parental strains, exhibited a high level of activity against coleopteran Rhyllodecta vulgatissima third-instar larvae, absent from the parental strains.

Animals↗

PubMed2005

Immobilization of Candida rugosa lipase on a pH-sensitive support for enantioselective hydrolysis of ketoprofen ester.

Candida rugosa lipase (Lipase OF) was immobilized by covalent binding to a pH-sensitive support showing reversibly soluble-insoluble characteristics with pH change. The immobilized lipase could carry out the enantioselective hydrolysis of ketoprofen ester in a soluble form yet be recovered after precipitation by simply adjusting pH. Its activity and enantioselectivity for hydrolysis of 2-chloroethyl ester of ketoprofen were enhanced 1.5-fold and 8.7-fold compared with those of free lipase. After eight catalytic cycles, the immobilized enzyme was still 46% active and its enantioselectivity remained unchanged.

Candida↗

PubMed2005

High yield of poly-gamma-glutamic acid from Bacillus subtilis by solid-state fermentation using swine manure as the basis of a solid substrate.

Solid-state fermentations (SSF), using swine manure as the basis of a solid substrate, were carried out for high yield of poly-gamma-glutamic acid (gamma-PGA) by Bacillus subtilis CCTCC202048. Fermentation medium and process parameters were optimized through three orthogonal array designs. The optimal medium consisted of 62.3% (w/w, dry weight basis) swine manure, 25.0% soybean cake, 5.0% wheat bran, 5.0% glutamic acid, 2.5% citric acid and 0.2% MnSO4.H2O. The optimal process parameters were 15.0 g medium with initial moisture content 60% and initial pH 9.0 in 250 ml flask, inoculation at mid-log phase with a 4% inoculum level and cultivation for 48 h at 37 degrees C. The average-PGA yield (6.0%) in triplicate under optimal conditions was obtained on the laboratory scale while it was 4.5% at compost experiment. These would lay a foundation for lessening the pollution of swine manure, increasing fertilizer efficiency and exploring a late-model organic fertilizer that retains water and nutrients.

Animals↗

PubMed2005

[Construction of Bacillus thuringiensis labeled recombinant strain and horizontal transfer of its cry1Ac10 gene].

A recombinant plasmid pBMBZGC10 was obtained by the ligation of gfp-cry1Ac10 fusion gene and vector plasmid pAD4412, which was then introduced by gene pulser into acrystalliferous strain CryB, and a recombinant strain CryB(pBMBZGC10) was obtained. Different fermentative solutions of recombinant strain were used for multi-spraying on Brassica pekinesis, Ipomoea aquatica and Lycopersicon esculentum leaves. The results of fluorescent detection and PCR amplification revealed that cry1Ac10 gene did not transfer into indigenous bacteria, actinomyces and fungi in test soil, and could not be detected in roots, stems and leaves of test plants.

Bacillus thuringiensis↗

PubMed2004

Enhanced expression of insecticidal crystal proteins in wild Bacillus thuringiensis strains by a heterogeneous protein P20.

P20 is a small chaperone-like protein encoded by a cry11A operon in Bacillus thuringiensis subsp. israelensis (Bti); it is essential to Cyt1Aa expression. In this report, the gene P20 was transformed into wild strains of subsp. kurstaki to raise the yield of crystal proteins. As a result, larger crystals were produced by the transformant than by the wild control, and most were in the form of a big bipyramid (average 2.4 microm long); some were irregular because of too high expression, while the spores turned out to be small spheroids unlike the long rods in the wild strains. SDS-PAGE analysis confirmed that Cry1A protoxin production was doubled by P20, but no increase of Cry2A production was observed. Besides, P20 caused obvious changes not only in bacterial morphology, but in the sporulation process as well. Further investigation discovered that a serious degradation happened to Cry1A in vivo of the wild strains, and reconfirmed that P20 was effective in preventing the degradation. Our results suggest that P20 is useful in engineered strain construction with enhanced protein expression.

Bacillus thuringiensis↗

PubMed2004

Melanin pigment formation and increased UV resistance in Bacillus thuringiensis following high temperature induction.

The pigment melanin is well known to protect against the damaging effects of UV radiation. In this study, we show that thirty-five of thirty-seven tested Bacillus thuringiensis strains possess the potential to produce melanin in the presence of L-tyrosin at elevated temperature (42 degrees C). These findings offer a method of protecting insecticidal toxins produced by B. thuringiensis from UV degredation and may therefore have important applications in the field of crop protection. Toxicity assays on Heliothis armigera suggested that the insecticidal activity of B. thuringiensis that produced melanin was significantly higher after UV irradiation than when melanin was not produced.

Animals↗

PubMed2004

Capacity of Bacillus thuringiensis S-layer protein displaying polyhistidine peptides on the cell surface.

S-layer protein of Bacillus thuringiensis strain CTC was used as the carrier protein to display polyhistidine (poly[6His]) peptides on the cell surface. Poly(6His)n was fused with S-layer protein at two different sites, inserting just downstream of the S-layer protein homologous domain (slh) and replacing the non-slh region of S-layer protein, respectively. The two series chimeric proteins were both expressed by crystal negative B. thuringiensis strain 4Q7 and strain 171, respectively, as shown by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The recombinant B. thuringiensis cells gained Ni(2+)- and Cd(2+)-binding ability and had a capacity to display up to nine copies of poly(6His). The Cd(2+) adsorption quantity of the recombinant strain with the strongest adsorption ability was twice that of the host strain.

Bacillus thuringiensis↗

PubMed2003

Protection of mice infected with Plasmodium berghei by Bacillus thuringiensis crystal proteins.

Eight Bacillus thuringiensis strains were used to test their activity against Plasmodium berghei. When crystal proteins extracted from strains 007, 017, 020, 021, 030, 032, and 037 were injected into plasmodium-infected mice through the tail vein at a rate of 0.45-1.5 mg per mouse, the lengths of survival for the mice were extended up to 5 days (from 8.5 days to 13.5-15 days). Blood-cell staining demonstrated that normal erythrocytes were lightly stained and regularly shaped while the erythrocytes from plasmodia-infected mice swelled, lost shape and even lysed. This means that the crystal proteins could protect erythrocytes from the plasmodium's attack. Proteins analysis revealed that most of the proteins are homologues of classic crystal proteins, with the exception of the 120-kDa protein of strain 020, a surface-layer protein. This study suggested a novel way to control plasmodial infections and even malaria.

Amino Acid Sequence↗

PubMed2003

Determination of spore concentration in Bacillus thuringiensis through the analysis of dipicolinate by capillary zone electrophoresis.

A new capillary zone electrophoresis (CZE) method for the analysis of dipicolinic acid, a specific component found in spores but not in vegetative cells, was used to determine spore concentration in Bacillus thuringiensis according to the relationship between the spore concentration and the content of dipicolinate. The quantitative relationship was established by using purified spores. Electrolyte conditions that affected the separation efficiency of dipicolinate and the reproducibility were investigated. With 10 mM phosphate, 10 mM ethylenediaminetetraacetic acid and 0.25 mM tetradecyltrimethylammonium bromide at pH 6.2 as the carrier electrolyte, dipicolinate can be determined within 8 min at an applied voltage of -25 kV (anode at detector) and a capillary temperature of 25 degrees C. The method has a high separation efficiency with which the number of theoretical plates is above 300,000 plates m(-1). The relative standard deviations for migration time and peak area are less than 0.5% and 2.0%, respectively. The detection limit for dipicolinate was 10 ng ml(-1), which corresponds to 7.2 x 10(5) spores ml(-1). The method was used to determine spores in fermentation broths, and the results obtained agreed well with the values obtained by plate counting.

Bacillus thuringiensis↗