Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have previously shown that pigment epithelium-derived factor (PEDF) acts as a survival factor for cerebellar granule cells (CGCs), by blocking apoptotic death, and can also protect these cells against glutamate-induced neurotoxicity. In preparation for gene therapy studies, pseudotyped HIV-1-based lentiviral vectors containing the PEDF gene, as well as either green fluorescent protein or beta-galactosidase, were prepared. These bicistronic vectors are unique in that they express two genes efficiently under one promoter. Primary cell cultures of CGCs from postnatal day 8 rats were infected with the vectors encoding PEDF. RT-PCR demonstrated expression of mRNA and Western blot analysis confirmed that infected CGCs secrete PEDF protein to the medium. Assays for cell survival demonstrated that PEDF-infected cells were significantly more protected compared with mock-infected controls for 6-8 days in culture, as well as against induced apoptosis. The PEDF vectors expressing tat (trans-acting transcription factor) provided more protection than the tat(-) vectors. These results demonstrate that while the lentiviral vectors expressing PEDF are as neuroprotective as the protein itself for CGCs, the vectors have the advantage of providing long-lasting expression of PEDF protein, which will be more effective in in vivo studies. The present results suggest that this system may be useful for gene therapy for neurodegenerative disorders.
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PMID:Survival effects of pigment epithelium-derived factor expressed by a lentiviral vector in rat cerebellar granule cells. 1150 37

Gene transfer provides an exciting new approach for the treatment of retinal and choroidal diseases. Two areas of concern are the potential for vector-related toxicity and uncertainties associated with prolonged transgene expression. One way to address these concerns for transfer of genes encoding secreted proteins is to transduce cells on the outside of the eye, provided the gene product can gain access to the eye and have the desired effect. In this study, we investigated the feasibility of this approach. Periocular injection of an adenoviral vector encoding beta-galactosidase (AdLacZ.10) resulted in LacZ-stained cells throughout the orbit and around the eye. Compared to periocular injection of 5 x 10(9) particles of control vector, periocular injection of 5 x 10(9) or 1 x 10(9) particles of an adenoviral vector expressing pigment epithelium-derived factor (PEDF) regulated by a CMV promoter (AdPEDF.11) resulted in significantly elevated intraocular levels of PEDF and suppression of choroidal neovascularization. Periocularly injected recombinant PEDF was also found to diffuse through the sclera into the eye. Although similar experiments are needed in an animal with a human-sized eye, these data suggest that periocular gene transfer deserves consideration for the treatment of choroidal diseases.
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PMID:Periocular injection of an adenoviral vector encoding pigment epithelium-derived factor inhibits choroidal neovascularization. 1269 92

Gene transfer provides a potential way to achieve sustained delivery of therapeutic proteins to the eye. Studies in rodents have suggested that periocular injection of adenoviral vectors containing expression cassettes for antiangiogenic proteins results in high intraocular levels of the proteins and suppression of choroidal neovascularization (CNV). However, the differences in size and scleral thickness between mouse and human eyes make it difficult to ascertain if periocular gene transfer is a feasible approach for treating human choroidal diseases. To address this issue, we tested the effect of periocular injection of an expression cassette for pigment epithelium-derived factor (PEDF) packaged in adenoviral vector (AdPEDF.11) in a CNV model in pigs, which have eyes that are very similar to humans in size and scleral thickness. Periocular injection of beta-galactosidase (AdLacZ.11) resulted in prominent transduction of periocular tissues, as was seen in mice. Periocular injection of AdPEDF.11 caused increased levels of PEDF in the choroid and significantly reduced the amount of CNV at rupture sites in Bruch's membrane. These data suggest that periocular gene transfer may be feasible for treatment of human choroidal diseases.
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PMID:Periocular gene transfer of pigment epithelium-derived factor inhibits choroidal neovascularization in a human-sized eye. 1587 78

Normal hepatocytes express pigment epithelium-derived factor (PEDF), an endogenous antiangiogenic factor. We hypothesized that decreased PEDF expression may be one mechanism driving hepatoblastoma growth, and in vivo gene transfer of PEDF could suppress neovascularization and limit tumor growth. PEDF functional activity was determined in vitro using endothelial cell migration assays and in vivo using a subcutaneous tumor model. HUH-6 human hepatoblastoma tumors were treated with hybrid adenoviral/adeno-associated viral expression vectors for PEDF (Hyb-PEDF, n = 4) or beta-galactosidase (Hyb-betagal, n = 4) daily for 4 d. Mitotic figures, microvascular density (MVD), PEDF, and VEGF expression were assessed. Hyb-PEDF treatment inhibited in vivo tumor growth (p < 0.008) and decreased MVD (p < 0.001), the number of mitotic figures (p < 0.001), and VEGF expression when compared with Hyb-betagal-treated tumors. HUH-6 expression of PEDF was dramatically reduced when cultured under hypoxic conditions and also when grown in vivo, and the addition of neutralizing anti-PEDF antibody increased the already high baseline angiogenic activity of the HUH-6 cell secretions in vitro (p < 0.04). PEDF is an important endogenous regulator of the liver vasculature. Augmenting intra-tumoral PEDF levels inhibits tumor growth by reducing angiogenesis and VEGF expression. Potent inhibitors of angiogenesis, such as PEDF, may be an effective alternative treatment for children with hepatoblastoma.
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PMID:Gene transfer of pigment epithelium-derived factor suppresses tumor growth and angiogenesis in a hepatoblastoma xenograft model. 1685 75

The 50-kDa secreted glycoprotein pigment epithelium-derived factor (PEDF) is neuroprotective for various types of cultured neurons, but whether it is neuroprotective for neurons in vivo is not known. We examined the effects of adenovirus-mediated gene transfer of PEDF on quinolinic acid (QA)-induced neurotoxicity in rats. Adenoviral vector containing the human PEDF gene (Ad.PEDF) or Escherichia coli beta-galactosidase gene (Ad.LacZ) was directly injected into the right striatum 7 days before the injection of QA. Immunohistochemical analysis using antibodies specific for the neuronal markers dopamine and cyclic adenosine monophosphate-regulated phosphoprotein of 32 kDa, neuronal nuclei, and choline acetyltransferase revealed that the QA-induced striatal damage was significantly reduced in Ad.PEDF-treated rats. Overexpression of PEDF also reduced the expression of the inflammation-related genes for interleukin 1beta, tumor necrosis factor alpha, and macrophage inflammatory protein 1alpha 1 day after QA injection. Deletion analysis of human PEDF protein demonstrated that overexpression of PEDFDelta44-121 failed to protect neurons against QA-induced excitotoxicity, whereas PEDFDelta78-121 retained the neuroprotective activity, suggesting that amino acid residues 44-77 of the PEDF sequence are essential for PEDF-mediated neuroprotection in vivo. These results provide the first evidence that PEDF and its deletion mutant PEDFDelta78-121 are effective in protecting CNS neurons against excitotoxicity in vivo.
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PMID:Adenoviral gene delivery of pigment epithelium-derived factor protects striatal neurons from quinolinic acid-induced excitotoxicity. 2014 68