Home About us Contact
|
Home About us Contact | ||
|
|
||
Adenoviral Expression (adenoviral + expression)
Terms modified by Adenoviral Expression Selected AbstractsChronic ethanol increases adeno-associated viral transgene expression in rat liver via oxidant and NF,B-dependent mechanismsHEPATOLOGY, Issue 5 2000Michael D. Wheeler Recombinant adeno-associated virus (rAAV) transduction is limited in vivo, yet can be enhanced by hydroxyurea, ultraviolet-irradiation, or adenovirus coinfection, possibly via mechanisms involving stress in the host cell. Because chronic ethanol induces oxidative stress, it was hypothesized that chronic ethanol would increase rAAV transduction in vivo. To test this hypothesis, rAAV encoding ,-galactosidase was given to Wistar rats that later received either ethanol diet or high-fat control diet via an enteral-feeding protocol for 3 weeks. Expression and activity of ,-galactosidase in the liver were increased nearly 5-fold by ethanol. The increase in transgene expression was inhibited by antioxidant diphenylene iodonium (DPI), which is consistent with the hypothesis that ethanol causes an increase in rAAV transduction via oxidative stress. Ethanol increased DNA synthesis only slightly; however, it increased the nuclear transcription factor ,B (NF,B) 4-fold, a phenomenon also sensitive to DPI. Moreover, a 6-fold increase in rAAV transgene expression was observed in an acute ischemia-reperfusion model of oxidative stress. Transgene expression was transiently increased 24 hours after ischemia-reperfusion 3 days and 3 weeks after rAAV infection. Further, adenoviral expression of superoxide dismutase or I,B, superrepressor inhibited rAAV transgene expression caused by ischemia-reperfusion. Therefore, it is concluded that ethanol increases rAAV transgene expression via mechanisms dependent on oxidative stress, and NF,B likely through enhancement of cytomegaloviral (CMV) promoter elements. Alcoholic liver disease is an attractive target for gene therapy because consumption of ethanol could theoretically increase expression of therapeutic genes (e.g., superoxide dismutase). Moreover, this study has important implications for rAAV gene therapy and potential enhancement and regulation of transgene expression in liver. [source] Bone Regeneration Is Regulated by Wnt Signaling,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 12 2007Jae-Beom Kim Abstract Tissue regeneration is increasingly viewed as reactivation of a developmental process that, when misappropriated, can lead to malignant growth. Therefore, understanding the molecular and cellular pathways that govern tissue regeneration provides a glimpse into normal development as well as insights into pathological conditions such as cancer. Herein, we studied the role of Wnt signaling in skeletal tissue regeneration. Introduction: Some adult tissues have the ability to regenerate, and among these, bone is one of the most remarkable. Bone exhibits a persistent, lifelong capacity to reform after injury, and continual bone regeneration is a prerequisite to maintaining bone mass and density. Even slight perturbations in bone regeneration can have profound consequences, as exemplified by conditions such as osteoporosis and delayed skeletal repair. Here, our goal was to determine the role of Wnts in adult bone regeneration. Materials and Methods: Using TOPgal reporter mice, we found that damage to the skeleton instigated Wnt reporter activity, specifically at the site of injury. We used a skeletal injury model to show that Wnt inhibition, achieved through adenoviral expression of Dkk1 in the adult skeleton, prevented the differentiation of osteoprogenitor cells. Results: As a result, injury-induced bone regeneration was reduced by 84% compared with controls. Constitutive activation of the Wnt pathway resulting from a mutation in the Lrp5 Wnt co-receptor results in high bone mass, but our experiments showed that this same point mutation caused a delay in bone regeneration. In these transgenic mice, osteoprogenitor cells in the injury site were maintained in a proliferative state and differentiation into osteoblasts was delayed. Conclusions: When considered together, these data provide a framework for understanding the roles of Wnt signaling in adult bone regeneration and suggest a feasible approach to treating clinical conditions where enhanced bone formation is desired. [source] In vivo molecular imaging of adenoviral versus lentiviral gene therapy in two bone formation modelsJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 8 2006Brian T. Feeley Abstract Regional gene therapy techniques are promising methods to enhance bone formation in large bone defects that would be difficult to treat with allograft or autograft bone stock. In this study, we compared in vivo temporal expression patterns of adenoviral- and lentiviral-mediated gene therapy in two bone formation models. Primary rat bone marrow cells (RBMC) were transduced with lentiviral or adenoviral vectors containing luciferase (Luc) or BMP-2 cDNA, or cotransduced with vectors containing Luc and bone morphogenetic protein 2 (BMP-2). In vitro protein production was determined with luciferase assay or ELISA (for BMP-2 production) weekly for 12 weeks. Two bone formation models were used,a hind limb muscle pouch or radial defect,in SCID mice. A cooled charged-coupled device (CCD) camera was used to image in vivo luciferase expression weekly for 12 weeks. In vitro, adenoviral expression of BMP-2 and luciferase was detected by ELISA or luciferase assay, respectively, for 4 weeks. Lentiviral expression of BMP-2 and luciferase was sustained in culture for 3 months. Using the CCD camera, we found that adenoviral vectors expressed luciferase expression for up to 21 days, but lentiviral vectors expressed target gene expression for 3 months in vivo in both bone formation models. There was no detectable difference in the amount of bone formed between the adenoviral and lentiviral groups. Lentiviral-mediated delivery of BMP-2 can induce long term in vitro and in vivo gene expression, which may be beneficial when developing tissue engineering strategies to heal large bone defects or defects with a compromised biologic environment. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:1709,1721, 2006 [source] Long-term tracing of adenoviral expression in rat and rabbit using luciferase imagingTHE JOURNAL OF GENE MEDICINE, Issue 6 2005Jin Zhong Li Abstract Background Luciferase optical imaging provides a novel method to monitor transgene expression in small living animals. As the genetic and immunological heritages of particular animals significantly affect the expression of adenovirus-delivered transgenes, it is essential to know the expression patterns specific to athymic nude and Sprague-Dawley rats, two strains commonly used in rodent models. In this study we set out to determine these patterns. At the same time, we tested luciferase optical imaging in a larger animal, the rabbit. Methods A recombinant luciferase adenoviral vector was injected subcutaneously or intramuscularly into athymic nude rats, Sprague-Dawley rats, and Dutch Belted rabbits. The luciferase expression was assessed using a cooled charge-coupled device. Results The luminescent signal was capable of passing through at least 1.3 cm of muscle tissue and proved to be much stronger when luciferin was delivered via a local injection than by an intraperitoneal injection. Although the types of immune cells differed between immunodeficient and immunocompetent rats, similar amounts and patterns of luciferase expression were observed in the musculature in two rat strains during the 1st month after a viral intramuscular injection. The duration of luciferase expression was longer than 15 months in athymic nude rats, 9 months in Sprague-Dawley rats, and 6 months in rabbits following a direct viral injection. Conclusions Luciferase expression after adenoviral gene delivery can persist for longer than 6 months, even in immunocompetent animals. Live imaging of luciferase expression can be performed not only in small animals, but also in larger animals such as rabbits. Copyright © 2005 John Wiley & Sons, Ltd. [source] Membrane type 1 matrix metalloproteinase is a crucial promoter of synovial invasion in human rheumatoid arthritisARTHRITIS & RHEUMATISM, Issue 3 2009Mary-Clare Miller Objective A hallmark of rheumatoid arthritis (RA) is invasion of the synovial pannus into cartilage, and this process requires degradation of the collagen matrix. The aim of this study was to explore the role of one of the collagen-degrading matrix metalloproteinases (MMPs), membrane type 1 MMP (MT1-MMP), in synovial pannus invasiveness. Methods The expression and localization of MT1-MMP in human RA pannus were investigated by Western blot analysis of primary synovial cells and immunohistochemical analysis of RA joint specimens. The functional role of MT1-MMP was analyzed by 3-dimensional (3-D) collagen invasion assays and a cartilage invasion assay in the presence or absence of tissue inhibitor of metalloproteinases 1 (TIMP-1), TIMP-2, or GM6001. The effect of adenoviral expression of a dominant-negative MT1-MMP construct lacking a catalytic domain was also examined. Results MT1-MMP was highly expressed at the pannus,cartilage junction in RA joints. Freshly isolated rheumatoid synovial tissue and isolated RA synovial fibroblasts invaded into a 3-D collagen matrix in an MT1-MMP,dependent manner. Invasion was blocked by TIMP-2 and GM6001 but not by TIMP-1. Invasion was also inhibited by the overexpression of a dominant-negative MT1-MMP, which inhibits collagenolytic activity and proMMP-2 activation by MT1-MMP on the cell surface. Synovial fibroblasts also invaded into cartilage in an MT1-MMP,dependent manner. This process was further enhanced by removing aggrecan from the cartilage matrix. Conclusion MT1-MMP serves as an essential collagen-degrading proteinase during pannus invasion in human RA. Specific inhibition of MT1-MMP,dependent invasion may represent a novel therapeutic strategy for RA. [source] | |||||||||||||