On the development of optical peripheral nerve interfaces

Limb loss and spinal cord injury are two debilitating conditions that continue to grow in prevalence. Prosthetic limbs and limb reanimation present two ways of providing affected individuals with means to interact in the world. These techniques are both dependent on a robust interface with the peripheral nerve. Current methods for interfacing with the peripheral nerve tend to suffer from low specificity, high latency and insufficient robustness for a chronic implant. An optical peripheral nerve interface may solve some of these problems by decreasing invasiveness and providing single axon specificity. In order to implement such an interface three elements are required:(1) a transducer capable of translating light into a neural stimulus or translating neural activity into changes in fluorescence,(2) a means for delivering said transducer and(3) a microscope for providing the stimulus light and detecting the fluorescence change. There are continued improvements in both genetically encoded calcium and voltage indicators as well as new optogenetic actuators for stimulation. Similarly, improvements in specificity of viral vectors continue to improve expression in the axons of the peripheral nerve. Our work has recently shown that it is possible to virally transduce axons of the peripheral nerve for recording from small fibers. The improvements of these components make an optical peripheral nerve interface a rapidly approaching alternative to current methods.

Gene therapy: light is finally in the tunnel

After two decades of ups and downs,gene therapy has recently achieved a milestone in treating patients with Leber’s congenital amaurosis(LCA).LCA is a group of inherited blinding diseases with retinal degeneration and severe vision loss in early infancy.Mutations in several genes,including RPE65,cause the disease.Using adenoassociated virus as a vector,three independent teams of investigators have recently shown that RPE65 can be delivered to retinal pigment epithelial cells of LCA patients by subretinal injections resulting in clinical benefits without side effects.However,considering the whole field of gene therapy,there are still major obstacles to clinical applications for other diseases.These obstacles include innate and immune barriers to vector delivery,toxicity of vectors and the lack of sustained therapeutic gene expression.Therefore,new strategies are needed to overcome these hurdles for achieving safe and effective gene therapy.In this article,we shall review the major advancements over the past two decades and,using lung gene therapy as an example,discuss the current obstacles and possible solutions to provide a roadmap for future gene therapy research.

Cytotoxic genes from traditional Chinese medicine inhibit tumor growth both in vitro and in vivo

OBJECTIVE： Little effort has been made to study the protein-encoding genes isolated from traditional Chinese medicine（TCM） drugs, and the delivery of these genes into malignant cells through recombinant adeno-associated virus（r AAV） vectors has not been attempted. METHODS： We synthesized the c DNAs of five known cytotoxic proteins isolated from TCM drugs and the FLAG epitope-tagged c DNAs were subcloned into a r AAV plasmid vector. The protein expression was confi rmed by Western blot assay. Various cancer cell lines were transfected with the above plasmids and cell growth was monitored both in vitro and in vivo. The best cytotoxic gene was further packaged into r AAV vectors, under the control of a liver cancer-specifi c promoter. The liver tumor growth was then monitored following intratumor administration of the r AAV vectors.RESULTS： The expression plasmids, encoding individual potential cytotoxic genes tagged with FLAG epitope, were successfully generated and sequenced. Among these genes, trichosanthin（TCS） gene yielded the most promising results for the inhibition of cancer cell growth in vitro. The over-expressed TCS functioned as a type I ribosome-inactivating protein, followed by inducing apoptosis that is associated with the Bcl-PARP signaling pathway. Furthermore, intratumor injection of r AAV vectors containing the TCS gene signifi cantly inhibited the growth of human hepatocellular carcinoma tumors in a murine xenograft model.CONCLUSION： Our studies suggest that the use of TCM cytotoxic genes is a useful therapeutic strategy for treating human cancers in general, and liver tumors in particular.

The E3 ubiquitin ligase HUWE1 acts through the N-Myc-DLL1-NOTCH1 signaling axis to suppress glioblastoma progression

Background:Elucidation of the post-transcriptional modification has led to novel strategies to treat intractable tumors,especially glioblastoma(GBM).The ubiquitin-proteasome system(UPS)mediates a reversible,stringent and stepwise post-translational modification which is closely associated with malignant processes of GBM.To this end,developing novel therapeutic approaches to target the UPS may contribute to the treatment of this disease.This study aimed to screen the vital and aberrantly regulated component of the UPS in GBM.Based on the molecular identification,functional characterization,and mechanism investigation,we sought to elaborate a novel therapeutic strategy to target this vital factor to combat GBM.Methods:We combined glioma datasets and human patient samples to screen and identify aberrantly regulated E3 ubiquitin ligase.Multidimensional database analysis and molecular and functional experiments in vivo and in vitro were used to evaluate the roles of HECT,UBA and WWE domain-containing E3 ubiquitin ligase 1(HUWE1)in GBM.dCas9 synergistic activation mediator system and recombinant adeno-associated virus(rAAV)were used to endogenously overexpress full-length HUWE1 in vitro and in glioma orthotopic xenografts.Results:Low expression of HUWE1 was closely associated with worse prognosis of GBM patients.The ubiquitination and subsequent degradation of N-Myc mediated by HUWE1,leading to the inactivation of downstream Delta-like 1(DLL1)-NOTCH1 signaling pathways,inhibited the proliferation,invasion,and migration of GBM cells in vitro and in vivo.A rAAV dual-vector system for packaging and delivery of dCas9-VP64 was used to augment endogenous HUWE1 expression in vivo and showed an antitumor activity in glioma orthotopic xenografts.Conclusions:The E3 ubiquitin ligase HUWE1 acts through the N-Myc-DLL1-NOTCH1 signaling axis to suppress GBM progression.Antitumor activity of rAAV dual-vector delivering dCas9-HUWE1 system uncovers a promising therapeutic strategy for GBM.