Home About us Contact
|
Home About us Contact | ||
|
|
||
Gene Transfer Strategies (gene + transfer_strategy)
Selected AbstractsGene Transfer Strategies for the PhysiologistEXPERIMENTAL PHYSIOLOGY, Issue 6 2000Liang-Fong Wong Foreign genes can be introduced into whole animals using methods of germline transgenesis and somatic gene delivery. While germline transgenesis can generate useful animal models for genetic studies, it can be costly, time-consuming and requires the use of a large number of animals. An alternative means of gene transfer is to deliver genes to somatic cells using non-viral and viral technologies. Non-viral methods such as naked DNA injection, electroporation and liposome/cation lipid-mediated gene transfer are relatively inefficient. In contrast, viruses are effective vehicles that carry foreign genes into a cell rapidly and efficiently. Here we illustrate the usefulness of adenoviral vectors to express a potent and specific inhibitor of cAMP-dependent protein kinase (PKA) to study the role of cyclic 3,,5,-cyclic AMP (cAMP) in the osmotic regulation of the vasopressin gene in a transgenic rat model. The ability to modify endogenous systems within specific cells in a whole animal model allows gene effects to be studied with physiological relevance. The combination of molecular biology and integrative physiology is a powerful application that can aid in the elucidation of how gene function can translate into complex systems in an organism [source] Cytoprotection of beta cells: rational gene transfer strategiesDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 3 2006Cillian McCabe Abstract Gene transfer to pancreatic islets may prove useful in preventing islet cell destruction and prolonging islet graft survival after transplantation in patients with type 1 diabetes mellitus (T1DM). Potentially, a host of therapeutically relevant transgenes may be incorporated into an appropriate gene delivery vehicle and used for islet modification. An increasing understanding of the molecular pathogenesis of immune-mediated beta cell death has served to highlight molecules which have become suitable candidates for promoting islet cell survival in the face of oxidative stress. This review aims to give an overview of some conventional gene transfer strategies aimed at promoting islet cell survival in the face of cytokine onslaught. These strategies target three aspects of islet cell physiology: redox status and antioxidant defence, anti-apoptotic gene expression and mediators of cytokine signal transduction pathways. Copyright © 2006 John Wiley & Sons, Ltd. [source] Gene transfer for hemophilia: can therapeutic efficacy in large animals be safely translated to patients?JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 8 2005K. HIGH Summary., Gene transfer is a novel area of therapeutics in which the active agent is a nucleic acid rather than a protein or small molecule. As early as 1997, investigators reported long-term expression of therapeutic levels of factor IX using gene transfer techniques in hemophilia B mice, and similar data were thereafter reported in mice with hemophilia A. Efforts to translate these results to hemophilic dog models at first yielded only marginally therapeutic levels (1%,2% normal circulating levels), but within the past few years have achieved levels in the range of 10%,20% through multiple different gene transfer strategies. Early phase clinical testing has revealed that many aspects of gene transfer in humans were accurately predicted by studies in hemophilic dogs, but that other aspects were not, and were only appreciated as a result of clinical testing. Studies in the next few years will determine whether the problems identified in preclinical and early phase clinical testing can be solved to develop a therapeutic gene transfer approach to hemophilia. [source] Timing of Human Insulin-Like Growth Factor-1 Gene Transfer in Reinnervating Laryngeal Muscle,THE LARYNGOSCOPE, Issue 4 2004Hideki Nakagawa MD Abstract Objectives/Hypothesis The authors have designed a rat laryngeal paralysis model to study gene transfer strategies using a muscle-specific expression system to enhance local delivery of human insulin-like growth factor-1 (hIGF-1). In preliminary studies, a nonviral vector containing the ,-actin promoter and human hIGF-1 sequence produced both neurotrophic and myotrophic effects 1 month after single injection of plasmid formulation into paralyzed rat thyroarytenoid muscle in vivo. Based on these findings, it is hypothesized that the effects of hIGF-1 will enhance the results of laryngeal muscle innervation procedures. The timing of gene delivery relative to nerve repair is likely to be important, to optimize the results. Study Design Prospective analysis. Methods The effects of nonviral gene transfer for the delivery of hIGF-1 were evaluated in rats treated immediately following recurrent laryngeal nerve transection and repair and in rats receiving a delayed treatment schedule, 30 days after nerve transection and repair. Gene transfer efficiency was determined using polymerase chain reaction and reverse transcriptase,polymerase chain reaction techniques. Muscle fiber diameter, motor endplate length, and percentage of motor endplates with nerve contact were examined to assess hIGF-1 trophic effects. Results Compared with reinnervated untreated control samples, both early and delayed hIGF-1 transfer resulted in significant increase in muscle fiber diameter. Motor endplate length was significantly decreased and nerve/motor endplate contact was significantly increased following delayed gene transfer, but not after early treatment. Conclusion We infer from results of the study that delayed hIGF-1 gene transfer delivered by a single intramuscular injection will enhance the process of muscle reinnervation. The clinical relevance of these findings supports the future application of gene therapy using nonviral vectors for management of laryngeal paralysis and other peripheral nerve injuries. [source] Poor intercellular transport and absence of enhanced antiproliferative activity after non-viral gene transfer of VP22-P53 or P53-VP22 fusions into p53 null cell lines in vitro or in vivoTHE JOURNAL OF GENE MEDICINE, Issue 7 2005David Zavaglia Abstract Background The herpes simplex virus type 1 (HSV-1) VP22 protein has the property to mediate intercellular trafficking of heterologous proteins fused to its C- or N-terminus. We have previously shown improved delivery and enhanced therapeutic effect in vitro and in vivo with a P27-VP22 fusion protein. In this report, we were interested in studying the spread and biological activity of VP22 fused to the P53 tumor suppressor. Methods Expression of the VP22-P53 and P53-VP22 fusion proteins was shown by Western blot and intercellular spreading was monitored by immunofluorescence on transiently transfected cells. In vitro antiproliferative activity of wild-type (wt) P53 and P53-VP22 was assessed by proliferation assays and transactivating ability was studied by a reporter gene test and a gel-shift assay. Antitumor activity was also tested in vivo by intratumoral injections of naked DNA in a model of subcutaneous tumors implanted in nude mice. Results Our results show that the C-terminal fusion or the N-terminal P53-VP22 fusion proteins are not able to spread as efficiently as VP22. Moreover, we demonstrate that VP22-P53 does not possess any transactivating ability. P53-VP22 has an antiproliferative activity, but this activity is not superior to the one of P53 alone, in vitro or in vivo. Conclusions Our study indicates that a gene transfer strategy using VP22 cannot be considered as a universal system to improve the delivery of any protein. Copyright © 2005 John Wiley & Sons, Ltd. [source] | |||||||||||||