Delivery of drugs and macromolecules to the central nervous system (CNS)

Delivery of drugs and macromolecules to the central nervous system (CNS) is hindered by the blood-brain barrier (BBB). of large amounts of cells expressing the enzymatically active protein. Selamectin Using double immunofluorescence (IF) with antibodies against tubulinIII and bacterial LacZ we identified these cells to be mostly neurons. A small proportion of the transduced cells was recognized as glial cells reacting positive in the IF with antibodies against astrocytic markers. These results demonstrate that our approach allows a very specific localized and efficient expression of intravenously administered transgenes in the brain of rats upon ultrasound-induced BBB opening. gene product enzymatically. A blue staining produced by cleavage of X-gal by active β-galactosidase was observed only in focal mostly cortical Selamectin areas of the insonated left hemisphere (Figure 2a c d) whereas the complete contralateral noninsonated hemisphere was not stained (Figure 2b). Most β-gal-positive foci were located in close vicinity to blood vessels and capillaries as depicted in Figure 2a. In addition to near-vascular β-galactosidase expressing cells in the brain parenchyma we also found successfully transduced cells forming part of the vessel walls (see arrows). Higher magnification (Figure 2c d) showed multiple spotted cells in the brain cortex with intracellular β-galactosidase. Figure 2 Histochemical demonstration of β-galactosidase in transfected cells. One week after insonation histochemistry for detection of the enzymatic activity of the β-galactosidase protein was performed to demonstrate the correct processing of … Immunofluorescence microscopy To further substantiate these results we performed immunofluorescence (IF) microscopy with a monoclonal antibody against β-galactosidase from study that modification of rAAV Selamectin particles by PEGylation impedes successful transduction possibly by impaired interaction with cell membrane receptors needed for receptor mediated endocytosis.29 Quantification of the transduction rates showed a large amount of transgene expression strictly limited to the sonicated regions. The transduction efficiency is a major advantage in the usage of viral gene transfer compared with the naked plasmid DNA. Huang and colleagues10 investigated the targeted delivery of the exogenous gene by focused ultrasound and microbubbles in 4-week-old mice. They Selamectin found that enhanced green fluorescent protein expression was limited to the cytoplasm of only some neurons at the sonicated regions. Consequently most clinical gene transfer studies have concentrated on viral vector strategies. To specify the cell tropism of distinct rAAV serotypes chimeric or pseudotyped vectors have recently been designed.19 Genomes containing the terminal repeats of a commonly used serotype mostly AAV2 can be packaged in capsids of another serotype resulting in modifications of transduction distribution and efficiency. For our study we constructed the chimeric rAAV2/1 which resulted in a widespread transduction of almost exclusively neurons in the sonicated regions. This observed pattern is consistent with previous studies demonstrating that direct injection of rAAV2/1 in several brain Selamectin structures of rats led to a higher number of transduced cells and a higher volume of distribution compared with the nonchimeric rAAV2/2. By choosing an appropriate promoter both the cell tropism Mouse monoclonal antibody to Hexokinase 1. Hexokinases phosphorylate glucose to produce glucose-6-phosphate, the first step in mostglucose metabolism pathways. This gene encodes a ubiquitous form of hexokinase whichlocalizes to the outer membrane of mitochondria. Mutations in this gene have been associatedwith hemolytic anemia due to hexokinase deficiency. Alternative splicing of this gene results infive transcript variants which encode different isoforms, some of which are tissue-specific. Eachisoform has a distinct N-terminus; the remainder of the protein is identical among all theisoforms. A sixth transcript variant has been described, but due to the presence of several stopcodons, it is not thought to encode a protein. [provided by RefSeq, Apr 2009] and the transduction efficiency can further be increased. In our experiments we used the strong cytomegalovirus (CMV) immediate-early promoter as vectors containing the CMV promoter have been shown to almost exclusively transduce neurons.16 In addition creation of hybrid form promoters30 and insertion of transcriptional control elements31 have recently led to optimized transduction efficiency. To further target gene therapy vectors cell type-specific binding ligands at the capsid surface have lately been investigated.32 Mueller and colleagues were the first to design random AAV peptide libraries in which each virus particle exhibits a random peptide at the capsid surface. By this means specific AAV vectors targeting endothelial cells33 as well as other cell lines or tissues have been selected. Concluding we could demonstrate for the first time.