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Chao-Yang Wang

Publications and source records attributed to Chao-Yang Wang.

6 recordsLinked to original sources
PubMed2006

Recombinant baculovirus containing the diphtheria toxin A gene for malignant glioma therapy.

Insect baculoviruses are capable of infecting mammalian glial cells in the central nervous system. We investigated in the current study the feasibility of using the viruses as toxin gene vectors to eliminate malignant glioma cells in the brain. We first confirmed that glioma cells were permissive to baculovirus infection, with variable transduction efficiencies at 100 viral particles per cell and ranging between 35% and 70% in seven human and rat glioma cell lines. We then developed a recombinant baculovirus vector accommodating the promoter of glial fibrillary acidic protein (GFAP) to minimize possible side effects caused by overexpression of a therapeutic gene in sensitive neurons. We placed the GFAP promoter into a baculovirus expression cassette, in which the enhancer of human cytomegalovirus immediate-early gene and the inverted terminal repeats of adeno-associated virus were employed to improve the relatively low transcriptional activity of the cellular promoter. This recombinant baculovirus significantly improved transduction in glioma cells, providing the efficiency in C6 rat glioma cells up to 96%. When used to produce the A-chain of diphtheria toxin intracellularly in a rat C6 glioma xenograft model, the baculovirus effectively suppressed tumor development. The new baculovirus vector circumvents some of the inherent problems associated with mammalian viral vectors and provides an additional option for cancer gene therapy.

Animals↗
PubMed2005

Adeno-associated virus inverted terminal repeats improve neuronal transgene expression mediated by baculoviral vectors in rat brain.

Baculoviral vectors can transduce neurons in the CNS but mediate only transient expression of transgenes. We have developed a new baculoviral vector in which the inverted terminal repeats (ITRs) of adeno-associated virus are used to flank a luciferase reporter gene cassette harboring a neuron-specific promoter. When tested in rat brain, the new viral vector was able to provide transgene expression for at least 90 days. Immunohistological analysis demonstrated that ITR flanking did not affect the cellular preference of the neuronal promoter in the context of baculovirus. These findings establish an effective way to engineer baculoviral vectors in order to achieve sustained expression of a functional gene for gene therapy for neurodegenerative disorders and physiological studies of neurons.

Animals↗
PubMed2004

Recombinant DNA vaccine encoding multiple domains related to inhibition of neurite outgrowth: a potential strategy for axonal regeneration.

Myelin-derived proteins, such as tenascin-R (TN-R), myelin associate glycoprotein (MAG), and Nogo-A, inhibit the CNS regeneration. By targeting specifically the inhibitory epitopes, we have investigated whether vaccination with a recombinant DNA molecule encoding multiple domains of myelin inhibitors may be useful in CNS repair. We show here that the recombinant DNA vaccine is able to activate the immune system but does not induce experimental autoimmune encephalomyelitis (EAE) in Lewis rats. Importantly, it promotes axonal regeneration in a spinal cord injury model. Thus, the application of DNA vaccine, encoding multiple specific domains of major inhibitory proteins and/or their receptors, provides another promising approach to overcome the inhibitory barriers during CNS regeneration.

Animals↗
PubMed2003

Nogo-A at CNS paranodes is a ligand of Caspr: possible regulation of K(+) channel localization.

We report Nogo-A as an oligodendroglial component congregating and interacting with the Caspr-F3 complex at paranodes. However, its receptor Nogo-66 receptor (NgR) does not segregate to specific axonal domains. CHO cells cotransfected with Caspr and F3, but not with F3 alone, bound specifically to substrates coated with Nogo-66 peptide and GST-Nogo-66. Binding persisted even after phosphatidylinositol- specific phospholipase C (PI-PLC) removal of GPI-linked F3 from the cell surface, suggesting a direct interaction between Nogo-66 and Caspr. Both Nogo-A and Caspr co-immunoprecipitated with Kv1.1 and Kv1.2, and the developmental expression pattern of both paralleled compared with Kv1.1, implicating a transient interaction between Nogo-A-Caspr and K(+) channels at early stages of myelination. In pathological models that display paranodal junctional defects (EAE rats, and Shiverer and CGT(-/-) mice), distances between the paired labeling of K(+) channels were shortened significantly and their localization shifted toward paranodes, while paranodal Nogo-A congregation was markedly reduced. Our results demonstrate that Nogo-A interacts in trans with axonal Caspr at CNS paranodes, an interaction that may have a role in modulating axon-glial junction architecture and possibly K(+)-channel localization during development.

Amino Acid Sequence↗
PubMed2002

Expression and purification of recombinant bone morphogenetic protein-2 in E.coli.

OBJECTIVE: To explore the method for producing human bone morphogenetic protein-2 (hBMP-2) by gene engineering techniques. METHODS: E.coli BL21 was transformed with recombinant plasmid pYR (pBV220-hBMP-2) under different conditions, and SDS-PAGE analysis was conducted to observe the effects of the activation status and induction time of the bacterium on the target protein expression. The inclusion bodies obtained from E.coli were purified by anion exchange chromatography DEAE and molecular sieve S-300, and the recombinant protein was renatured by dialyse. RESULTS: SDS-PAGE analysis showed a conspicuous band after induction signifying a new foreign protein with relative molecular mass of approximately 13 000. After activation of the bacteria when D600 was about 0.45, most efficient expression of rhBMP-2 was achieved which reached the peak 4 h after induction with heat. Implantation of the purified recombinant hBMP-2 resulted in proliferation of mesenchymal cells and new cartilage and bone formation, as shown by histological analysis 4 weeks after implantation. CONCLUSION: hBMP-2 produced by gene engineering techniques possesses the biological capacity of ectopic bone formation.

Animals↗