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Sample records for retinal gene therapy

  1. Gene Therapy for Retinal Diseases

    PubMed Central

    Samiy, Nasrollah

    2014-01-01

    Gene therapy has a growing research potential particularly in the field of ophthalmic and retinal diseases owing to three main characteristics of the eye; accessibility in terms of injections and surgical interventions, its immune-privileged status facilitating the accommodation to the antigenicity of a viral vector, and tight blood-ocular barriers which save other organs from unwanted contamination. Gene therapy has tremendous potential for different ocular diseases. In fact, the perspective of gene therapy in the field of eye research does not confine to exclusive monogenic ophthalmic problems and it has the potential to include gene based pharmacotherapies for non-monogenic problems such as age related macular disease and diabetic retinopathy. The present article has focused on how gene transfer into the eye has been developed and used to treat retinal disorders with no available therapy at present. PMID:25709778

  2. What Is Next for Retinal Gene Therapy?

    PubMed Central

    Vandenberghe, Luk H.

    2015-01-01

    The field of gene therapy for retinal blinding disorders is experiencing incredible momentum, justified by hopeful results in early stage clinical trials for inherited retinal degenerations. The premise of the use of the gene as a drug has come a long way, and may have found its niche in the treatment of retinal disease. Indeed, with only limited treatment options available for retinal indications, gene therapy has been proven feasible, safe, and effective and may lead to durable effects following a single injection. Here, we aim at putting into context the promise and potential, the technical, clinical, and economic boundaries limiting its application and development, and speculate on a future in which gene therapy is an integral component of ophthalmic clinical care. PMID:25877395

  3. [Gene therapy for inherited retinal dystrophies].

    PubMed

    Côco, Monique; Han, Sang Won; Sallum, Juliana Maria Ferraz

    2009-01-01

    The inherited retinal dystrophies comprise a large number of disorders characterized by a slow and progressive retinal degeneration. They are the result of mutations in genes that express in either the photoreceptor cells or the retinal pigment epithelium. The mode of inheritance can be autosomal dominant, autosomal recessive, X linked recessive, digenic or mitochondrial DNA inherited. At the moment, there is no treatment for these conditions and the patients can expect a progressive loss of vision. Accurate genetic counseling and support for rehabilitation are indicated. Research into the molecular and genetic basis of disease is continually expanding and improving the prospects for rational treatments. In this way, gene therapy, defined as the introduction of exogenous genetic material into human cells for therapeutic purposes, may ultimately offer the greatest treatment for the inherited retinal dystrophies. The eye is an attractive target for gene therapy because of its accessibility, immune privilege and translucent media. A number of retinal diseases affecting the eye have known gene defects. Besides, there is a well characterized animal model for many of these conditions. Proposals for clinical trials of gene therapy for inherited retinal degenerations owing to defects in the gene RPE65, have recently received ethical approval and the obtained preliminary results brought large prospects in the improvement on patient's quality of life. PMID:19820803

  4. Prospects for retinal gene replacement therapy.

    PubMed

    Smith, Alexander J; Bainbridge, James W; Ali, Robin R

    2009-04-01

    Inherited retinal degeneration, which includes conditions such as retinitis pigmentosa and Leber congenital amaurosis (LCA), affects approximately 1/3000 of the population in the Western world. It is characterized by loss of vision and results from mutations in any one of >100 different genes. There are currently no effective treatments, but many of the genes have now been identified and their functions elucidated, providing a major impetus to develop gene-based treatments. Preliminary results from three clinical trials indicate that the treatment of a form of LCA by gene therapy can be safe and effective. Here, we discuss the potential for treating other forms of retinal degeneration by gene therapy, focusing on the gene defects that are likely to be the most amenable to treatment. PMID:19303164

  5. Prospectives for Gene Therapy of Retinal Degenerations

    PubMed Central

    Thumann, Gabriele

    2012-01-01

    Retinal degenerations encompass a large number of diseases in which the retina and associated retinal pigment epithelial (RPE) cells progressively degenerate leading to severe visual disorders or blindness. Retinal degenerations can be divided into two groups, a group in which the defect has been linked to a specific gene and a second group that has a complex etiology that includes environmental and genetic influences. The first group encompasses a number of relatively rare diseases with the most prevalent being Retinitis pigmentosa that affects approximately 1 million individuals worldwide. Attempts have been made to correct the defective gene by transfecting the appropriate cells with the wild-type gene and while these attempts have been successful in animal models, human gene therapy for these inherited retinal degenerations has only begun recently and the results are promising. To the second group belong glaucoma, age-related macular degeneration (AMD) and diabetic retinopathy (DR). These retinal degenerations have a genetic component since they occur more often in families with affected probands but they are also linked to environmental factors, specifically elevated intraocular pressure, age and high blood sugar levels respectively. The economic and medical impact of these three diseases can be assessed by the number of individuals affected; AMD affects over 30 million, DR over 40 million and glaucoma over 65 million individuals worldwide. The basic defect in these diseases appears to be the relative lack of a neurogenic environment; the neovascularization that often accompanies these diseases has suggested that a decrease in pigment epithelium-derived factor (PEDF), at least in part, may be responsible for the neurodegeneration since PEDF is not only an effective neurogenic and neuroprotective agent but also a potent inhibitor of neovascularization. In the last few years inhibitors of vascularization, especially antibodies against vascular endothelial cell

  6. Retinal Gene Therapy: Current Progress and Future Prospects

    PubMed Central

    Ku, Cristy A.; Pennesi, Mark E.

    2015-01-01

    Clinical trials treating inherited retinal dystrophy caused by RPE65 mutations had put retinal gene therapy at the forefront of gene therapy. Both successes and limitations in these clinical trials have fueled developments in gene vectors, which continue to further advance the field. These novel gene vectors aim to more safely and efficiently transduce retinal cells, expand the gene packaging capacity of AAV, and utilize new strategies to correct the varying mechanisms of dysfunction found with inherited retinal dystrophies. With recent clinical trials and numerous pre-clinical studies utilizing these novel vectors, the future of ocular gene therapy continues to hold vast potential. PMID:26609316

  7. Progress in gene targeting and gene therapy for retinitis pigmentosa

    SciTech Connect

    Farrar, G.J.; Humphries, M.M.; Erven, A.

    1994-09-01

    Previously, we localized disease genes involved in retinitis pigmentosa (RP), an inherited retinal degeneration, close to the rhodopsin and peripherin genes on 3q and 6p. Subsequently, we and others identified mutations in these genes in RP patients. Currently animal models for human retinopathies are being generated using gene targeting by homologous recombination in embryonic stem (ES) cells. Genomic clones for retinal genes including rhodopsin and peripherin have been obtained from a phage library carrying mouse DNA isogenic with the ES cell line (CC1.2). The peripherin clone has been sequenced to establish the genomic structure of the mouse gene. Targeting vectors for rhodopsin and peripherin including a neomycin cassette for positive selection and thymidine kinase genes enabling selection against random intergrants are under construction. Progress in vector construction will be presented. Simultaneously we are developing systems for delivery of gene therapies to retinal tissues utilizing replication-deficient adenovirus (Ad5). Efficacy of infection subsequent to various methods of intraocular injection and with varying viral titers is being assayed using an adenovirus construct containing a CMV promoter LacZ fusion as reporter and the range of tissues infected and the level of duration of LacZ expression monitored. Viral constructs with the LacZ reporter gene under the control of retinal specific promoters such as rhodopsin and IRBP cloned into pXCJL.1 are under construction. An update on developments in photoreceptor cell-directed expression of virally delivered genes will be presented.

  8. Nanoparticle-based Technologies for Retinal Gene Therapy

    PubMed Central

    Adijanto, Jeffrey; Naash, Muna I

    2015-01-01

    For patients with hereditary retinal diseases, retinal gene therapy offers significant promise for the prevention of retinal degeneration. While adeno-associated virus (AAV)-based systems remain the most popular gene delivery method due to their high efficiency and successful clinical results, other delivery systems, such as non-viral nanoparticles (NPs) are being developed as additional therapeutic options. NP technologies come in several categories (e.g., polymer, liposomes, peptide compacted DNA), several of which have been tested in mouse models of retinal disease. Here, we discuss the key biochemical features of the different NPs that influence how they are internalized into cells, escape from endosomes, and are delivered into the nucleus. We review the primary mechanism of NP uptake by retinal cells and highlight various NPs that have been successfully used for in vivo gene delivery to the retina and RPE. Finally, we consider the various strategies that can be implemented in the plasmid DNA to generate persistent, high levels of gene expression. PMID:25592325

  9. Human retinal gene therapy for Leber congenital amaurosis shows advancing retinal degeneration despite enduring visual improvement.

    PubMed

    Cideciyan, Artur V; Jacobson, Samuel G; Beltran, William A; Sumaroka, Alexander; Swider, Malgorzata; Iwabe, Simone; Roman, Alejandro J; Olivares, Melani B; Schwartz, Sharon B; Komáromy, András M; Hauswirth, William W; Aguirre, Gustavo D

    2013-02-01

    Leber congenital amaurosis (LCA) associated with retinal pigment epithelium-specific protein 65 kDa (RPE65) mutations is a severe hereditary blindness resulting from both dysfunction and degeneration of photoreceptors. Clinical trials with gene augmentation therapy have shown partial reversal of the dysfunction, but the effects on the degeneration are not known. We evaluated the consequences of gene therapy on retinal degeneration in patients with RPE65-LCA and its canine model. In untreated RPE65-LCA patients, there was dysfunction and degeneration of photoreceptors, even at the earliest ages. Examined serially over years, the outer photoreceptor nuclear layer showed progressive thinning. Treated RPE65-LCA showed substantial visual improvement in the short term and no detectable decline from this new level over the long term. However, retinal degeneration continued to progress unabated. In RPE65-mutant dogs, the first one-quarter of their lifespan showed only dysfunction, and there was normal outer photoreceptor nuclear layer thickness retina-wide. Dogs treated during the earlier dysfunction-only stage showed improved visual function and dramatic protection of treated photoreceptors from degeneration when measured 5-11 y later. Dogs treated later during the combined dysfunction and degeneration stage also showed visual function improvement, but photoreceptor loss continued unabated, the same as in human RPE65-LCA. The results suggest that, in RPE65 disease treatment, protection from visual function deterioration cannot be assumed to imply protection from degeneration. The effects of gene augmentation therapy are complex and suggest a need for a combinatorial strategy in RPE65-LCA to not only improve function in the short term but also slow retinal degeneration in the long term. PMID:23341635

  10. Gene Therapy to Rescue Retinal Degeneration Caused by Mutations in Rhodopsin

    PubMed Central

    Rossmiller, Brian P.; Ryals, Renee C.; Lewin, Alfred S.

    2015-01-01

    Retinal gene therapy has proven safe and at least partially successful in clinical trials and in numerous animal models. Gene therapy requires characterization of the progression of the disease and understanding of its genetic cause. Testing gene therapies usually requires an animal model that recapitulates the key features of the human disease, though photoreceptors and cells of the retinal pigment epithelium produced from patient-derived stem cells may provide an alternative test system for retinal gene therapy. Gene therapy also requires a delivery system that introduces the therapeutic gene to the correct cell type and does not cause unintended damage to the tissue. Current systems being tested in the eye are nanoparticles, pseudotyped lentiviruses, and adeno-associated virus (AAV) of various serotypes. Here, we describe the techniques of AAV vector design as well as the in vivo and ex vivo tests necessary for assessing the efficacy of retinal gene therapy to treat retinal degeneration caused by mutations in the rhodopsin gene. PMID:25697537

  11. Dawn of ocular gene therapy: implications for molecular diagnosis in retinal disease

    PubMed Central

    Jacques, ZANEVELD; Feng, WANG; Xia, WANG; Rui, CHEN

    2013-01-01

    Personalized medicine aims to utilize genomic information about patients to tailor treatment. Gene replacement therapy for rare genetic disorders is perhaps the most extreme form of personalized medicine, in that the patients’ genome wholly determines their treatment regimen. Gene therapy for retinal disorders is poised to become a clinical reality. The eye is an optimal site for gene therapy due to the relative ease of precise vector delivery, immune system isolation, and availability for monitoring of any potential damage or side effects. Due to these advantages, clinical trials for gene therapy of retinal diseases are currently underway. A necessary precursor to such gene therapies is accurate molecular diagnosis of the mutation(s) underlying disease. In this review, we discuss the application of Next Generation Sequencing (NGS) to obtain such a diagnosis and identify disease causing genes, using retinal disorders as a case study. After reviewing ocular gene therapy, we discuss the application of NGS to the identification of novel Mendelian disease genes. We then compare current, array based mutation detection methods against next NGS-based methods in three retinal diseases: Leber’s Congenital Amaurosis, Retinitis Pigmentosa, and Stargardt’s disease. We conclude that next-generation sequencing based diagnosis offers several advantages over array based methods, including a higher rate of successful diagnosis and the ability to more deeply and efficiently assay a broad spectrum of mutations. However, the relative difficulty of interpreting sequence results and the development of standardized, reliable bioinformatic tools remain outstanding concerns. In this review, recent advances NGS based molecular diagnoses are discussed, as well as their implications for the development of personalized medicine. PMID:23393028

  12. Myosin7a Deficiency Results in Reduced Retinal Activity Which Is Improved by Gene Therapy

    PubMed Central

    Colella, Pasqualina; Sommella, Andrea; Marrocco, Elena; Di Vicino, Umberto; Polishchuk, Elena; Garrido, Marina Garcia; Seeliger, Mathias W.; Polishchuk, Roman; Auricchio, Alberto

    2013-01-01

    Mutations in MYO7A cause autosomal recessive Usher syndrome type IB (USH1B), one of the most frequent conditions that combine severe congenital hearing impairment and retinitis pigmentosa. A promising therapeutic strategy for retinitis pigmentosa is gene therapy, however its pre-clinical development is limited by the mild retinal phenotype of the shaker1 (sh1−/−) murine model of USH1B which lacks both retinal functional abnormalities and degeneration. Here we report a significant, early-onset delay of sh1−/− photoreceptor ability to recover from light desensitization as well as a progressive reduction of both b-wave electroretinogram amplitude and light sensitivity, in the absence of significant loss of photoreceptors up to 12 months of age. We additionally show that subretinal delivery to the sh1−/− retina of AAV vectors encoding the large MYO7A protein results in significant improvement of sh1−/− photoreceptor and retinal pigment epithelium ultrastructural anomalies which is associated with improvement of recovery from light desensitization. These findings provide new tools to evaluate the efficacy of experimental therapies for USH1B. In addition, although AAV vectors expressing large genes might have limited clinical applications due to their genome heterogeneity, our data show that AAV-mediated MYO7A gene transfer to the sh1−/− retina is effective. PMID:23991031

  13. Non-Invasive Gene Transfer by Iontophoresis for Therapy of an Inherited Retinal Degeneration

    PubMed Central

    Souied, Eric H.; Reid, Silvia N. M.; Piri, Natik I.; Lerner, Leonid E.; Nusinowitz, Steven; Farber, Debora B.

    2009-01-01

    Despite extensive research on many of the genes responsible for inherited retinal degenerations leading to blindness, no effective treatment is currently available for patients affected with these diseases. Among the therapeutic approaches tested on animal models of human retinal degeneration, gene therapy using different types of viral vectors as delivery agents has yielded promising results. We report here our results on a non-invasive, non-viral delivery approach using transscleral iontophoresis for transfer of plasmid DNA into mouse retina. Proof of principle experiments were carried out using plasmid containing GFP cDNA to demonstrate expression of the transferred gene in the retina after single applications of iontophoresis. Various parameters for multiple applications of iontophoresis were optimized to sustain GFP gene expression in mouse photoreceptors. Subsequently, repeated iontophoresis of plasmid containing normal β-phosphodiesterase (β-PDE) cDNA was performed in the rd1 mouse, an animal model of autosomal recessive retinitis pigmentosa caused by a mutant β-PDE gene. In normal mice, transscleral iontophoresis of the GFP plasmid provided a significant increase in fluorescence of the retina in the treated versus non-treated eyes. In rd1 mice, repeated iontophoresis of β-PDE cDNA plasmid partially rescued photoreceptors morphologically, as observed by microscopy, and functionally, as recorded on ERG measurements, without adverse effects. Therefore, transscleral iontophoresis of plasmid DNA containing therapeutic genes may be an efficient, safe and non-invasive method for the treatment of retinal degenerations. PMID:18653181

  14. AAV-mediated Gene Therapy Halts Retinal Degeneration in PDE6β-deficient Dogs.

    PubMed

    Pichard, Virginie; Provost, Nathalie; Mendes-Madeira, Alexandra; Libeau, Lyse; Hulin, Philippe; Tshilenge, Kizito-Tshitoko; Biget, Marine; Ameline, Baptiste; Deschamps, Jack-Yves; Weber, Michel; Le Meur, Guylène; Colle, Marie-Anne; Moullier, Philippe; Rolling, Fabienne

    2016-05-01

    We previously reported that subretinal injection of AAV2/5 RK.cpde6β allowed long-term preservation of photoreceptor function and vision in the rod-cone dysplasia type 1 (rcd1) dog, a large animal model of naturally occurring PDE6β deficiency. The present study builds on these earlier findings to provide a detailed assessment of the long-term effects of gene therapy on the spatiotemporal pattern of retinal degeneration in rcd1 dogs treated at 20 days of age. We analyzed the density distribution of the retinal layers and of particular photoreceptor cells in 3.5-year-old treated and untreated rcd1 dogs. Whereas no rods were observed outside the bleb or in untreated eyes, gene transfer halted rod degeneration in all vector-exposed regions. Moreover, while gene therapy resulted in the preservation of cones, glial cells and both the inner nuclear and ganglion cell layers, no cells remained in vector-unexposed retinas, except in the visual streak. Finally, the retinal structure of treated 3.5-year-old rcd1 dogs was identical to that of unaffected 4-month-old rcd1 dogs, indicating near complete preservation. Our findings indicate that gene therapy arrests the degenerative process even if intervention is initiated after the onset of photoreceptor degeneration, and point to significant potential of this therapeutic approach in future clinical trials. PMID:26857842

  15. Gene Therapy for MERTK-Associated Retinal Degenerations

    PubMed Central

    Matthes, Michael T.; Yang, Haidong; Hauswirth, William W.; Deng, Wen-Tao; Vollrath, Douglas

    2016-01-01

    MERTK-associated retinal degenerations are thought to have defects in phagocytosis of shed outer segment membranes by the retinal pigment epithelium (RPE), as do the rodent models of these diseases. We have subretinally injected an RPE-specific AAV2 vector, AAV2-VMD2-hMERTK, to determine whether this would provide long-term photoreceptor rescue in the RCS rat, which it did for up to 6.5 months, the longest time point examined. Moreover, we found phagosomes in the RPE in the rescued regions of RCS retinas soon after the onset of light. The same vector also had a major protective effect in Mertk-null mice, with a concomitant increase in ERG response amplitudes in the vector-injected eyes. These findings suggest that planned clinical trials with this vector will have a favorable outcome. PMID:26427450

  16. The intricacies of neurotrophic factor therapy for retinal ganglion cell rescue in glaucoma: a case for gene therapy

    PubMed Central

    Foldvari, Marianna; Chen, Ding Wen

    2016-01-01

    Regeneration of damaged retinal ganglion cells (RGC) and their axons is an important aspect of reversing vision loss in glaucoma patients. While current therapies can effectively lower intraocular pressure, they do not provide extrinsic support to RGCs to actively aid in their protection and regeneration. The unmet need could be addressed by neurotrophic factor gene therapy, where plasmid DNA, encoding neurotrophic factors, is delivered to retinal cells to maintain sufficient levels of neurotrophins in the retina. In this review, we aim to describe the intricacies in the design of the therapy including: the choice of neurotrophic factor, the site and route of administration and target cell populations for gene delivery. Furthermore, we also discuss the challenges currently being faced in RGC-related therapy development with special considerations to the existence of multiple RGC subtypes and the lack of efficient and representative in vitro models for rapid and reliable screening in the drug development process. PMID:27482199

  17. Personalized Medicine: Cell and Gene Therapy Based on Patient-Specific iPSC-Derived Retinal Pigment Epithelium Cells.

    PubMed

    Li, Yao; Chan, Lawrence; Nguyen, Huy V; Tsang, Stephen H

    2016-01-01

    Interest in generating human induced pluripotent stem (iPS) cells for stem cell modeling of diseases has overtaken that of patient-specific human embryonic stem cells due to the ethical, technical, and political concerns associated with the latter. In ophthalmology, researchers are currently using iPS cells to explore various applications, including: (1) modeling of retinal diseases using patient-specific iPS cells; (2) autologous transplantation of differentiated retinal cells that undergo gene correction at the iPS cell stage via gene editing tools (e.g., CRISPR/Cas9, TALENs and ZFNs); and (3) autologous transplantation of patient-specific iPS-derived retinal cells treated with gene therapy. In this review, we will discuss the uses of patient-specific iPS cells for differentiating into retinal pigment epithelium (RPE) cells, uncovering disease pathophysiology, and developing new treatments such as gene therapy and cell replacement therapy via autologous transplantation. PMID:26427458

  18. Limbal Approach-Subretinal Injection of Viral Vectors for Gene Therapy in Mice Retinal Pigment Epithelium.

    PubMed

    Park, Sung Wook; Kim, Jin Hyoung; Park, Woo Jin; Kim, Jeong Hun

    2015-01-01

    The eye is a small and enclosed organ which makes it an ideal target for gene therapy. Recently various strategies have been applied to gene therapy in retinopathies using non-viral and viral gene delivery to the retina and retinal pigment epithelium (RPE). Subretinal injection is the best approach to deliver viral vectors directly to RPE cells. Before the clinical trial of a gene therapy, it is inevitable to validate the efficacy of the therapy in animal models of various retinopathies. Thus, subretinal injection in mice becomes a fundamental technique for an ocular gene therapy. In this protocol, we provide the easy and replicable technique for subretinal injection of viral vectors to experimental mice. This technique is modified from the intravitreal injection, which is widely used technique in ophthalmology clinics. The representative results of RPE/choroid/scleral complex flat-mount will help to understand the efficacy of this technique and adjust the volume and titer of viral vectors for the extent of gene transduction. PMID:26274541

  19. A review of therapeutic prospects of non-viral gene therapy in the retinal pigment epithelium

    PubMed Central

    Koirala, Adarsha; Conley, Shannon M.; Naash, Muna I.

    2013-01-01

    Ocular gene therapy has been extensively explored in recent years as a therapeutic avenue to target diseases of the cornea, retina and retinal pigment epithelium (RPE). Adeno-associated virus (AAV)-mediated gene therapy has shown promise in several RPE clinical trials but AAVs have limited payload capacity and potential immunogenicity. Traditionally however, non-viral alternatives have been plagued by low transfection efficiency, short-term expression and low expression levels. Recently, these drawbacks have begun to be overcome by the use of specialty carriers such as polylysine, liposomes, or polyethyleneimines, and by inclusion of suitable DNA elements to enhance gene expression and longevity. Recent advancements in the field have yielded non-viral vectors that have favorable safety profiles, lack immunogenicity, exhibit long-term elevated gene expression, and show efficient transfection in the retina and RPE, making them poised to transition to clinical applications. Here we discuss the advancements in nanotechnology and vector engineering that have improved the prospects for clinical application of non-viral gene therapy in the RPE. PMID:23796578

  20. Coating nanocarriers with hyaluronic acid facilitates intravitreal drug delivery for retinal gene therapy.

    PubMed

    Martens, Thomas F; Remaut, Katrien; Deschout, Hendrik; Engbersen, Johan F J; Hennink, Wim E; van Steenbergen, Mies J; Demeester, Jo; De Smedt, Stefaan C; Braeckmans, Kevin

    2015-03-28

    Retinal gene therapy could potentially affect the lives of millions of people suffering from blinding disorders. Yet, one of the major hurdles remains the delivery of therapeutic nucleic acids to the retinal target cells. Due to the different barriers that need to be overcome in case of topical or systemic administration, intravitreal injection is an attractive alternative administration route for large macromolecular therapeutics. Here it is essential that the therapeutics do not aggregate and remain mobile in the vitreous humor in order to reach the retina. In this study, we have evaluated the use of hyaluronic acid (HA) as an electrostatic coating for nonviral polymeric gene nanomedicines, p(CBA-ABOL)/pDNA complexes, to provide them with an anionic hydrophilic surface for improved intravitreal mobility. Uncoated polyplexes had a Z-averaged diameter of 108nm and a zeta potential of +29mV. We evaluated polyplexes coated with HA of different molecular weights (22kDa, 137kDa and 2700kDa) in terms of size, surface charge and complexation efficiency and noticed their zeta potentials became anionic at 4-fold molar excess of HA-monomers compared to cationic monomers, resulting in submicron ternary polyplexes. Next, we used a previously optimized ex vivo model based on excised bovine eyes and fluorescence single particle tracking (fSPT) microscopy to evaluate mobility in intact vitreous humor. It was confirmed that HA-coated polyplexes had good mobility in bovine vitreous humor, similar to polyplexes functionalized with polyethylene glycol (PEG), except for those coated with high molecular weight HA (2700kDa). However, contrary to PEGylated polyplexes, HA-coated polyplexes were efficiently taken up in vitro in ARPE-19 cells, despite their negative charge, indicating uptake via CD44-receptor mediated endocytosis. Furthermore, the HA-polyplexes were able to induce GFP expression in this in vitro cell line without apparent cytotoxicity, where coating with low molecular

  1. Successful arrest of photoreceptor and vision loss expands the therapeutic window of retinal gene therapy to later stages of disease

    PubMed Central

    Beltran, William A.; Cideciyan, Artur V.; Iwabe, Simone; Swider, Malgorzata; Kosyk, Mychajlo S.; McDaid, Kendra; Martynyuk, Inna; Ying, Gui-Shuang; Shaffer, James; Deng, Wen-Tao; Boye, Sanford L.; Lewin, Alfred S.; Hauswirth, William W.; Jacobson, Samuel G.; Aguirre, Gustavo D.

    2015-01-01

    Inherited retinal degenerations cause progressive loss of photoreceptor neurons with eventual blindness. Corrective or neuroprotective gene therapies under development could be delivered at a predegeneration stage to prevent the onset of disease, as well as at intermediate-degeneration stages to slow the rate of progression. Most preclinical gene therapy successes to date have been as predegeneration interventions. In many animal models, as well as in human studies, to date, retinal gene therapy administered well after the onset of degeneration was not able to modify the rate of progression even when successfully reversing dysfunction. We evaluated consequences of gene therapy delivered at intermediate stages of disease in a canine model of X-linked retinitis pigmentosa (XLRP) caused by a mutation in the Retinitis Pigmentosa GTPase Regulator (RPGR) gene. Spatiotemporal natural history of disease was defined and therapeutic dose selected based on predegeneration results. Then interventions were timed at earlier and later phases of intermediate-stage disease, and photoreceptor degeneration monitored with noninvasive imaging, electrophysiological function, and visual behavior for more than 2 y. All parameters showed substantial and significant arrest of the progressive time course of disease with treatment, which resulted in long-term improved retinal function and visual behavior compared with control eyes. Histology confirmed that the human RPGR transgene was stably expressed in photoreceptors and associated with improved structural preservation of rods, cones, and ON bipolar cells together with correction of opsin mislocalization. These findings in a clinically relevant large animal model demonstrate the long-term efficacy of RPGR gene augmentation and substantially broaden the therapeutic window for intervention in patients with RPGR-XLRP. PMID:26460017

  2. Successful arrest of photoreceptor and vision loss expands the therapeutic window of retinal gene therapy to later stages of disease.

    PubMed

    Beltran, William A; Cideciyan, Artur V; Iwabe, Simone; Swider, Malgorzata; Kosyk, Mychajlo S; McDaid, Kendra; Martynyuk, Inna; Ying, Gui-Shuang; Shaffer, James; Deng, Wen-Tao; Boye, Sanford L; Lewin, Alfred S; Hauswirth, William W; Jacobson, Samuel G; Aguirre, Gustavo D

    2015-10-27

    Inherited retinal degenerations cause progressive loss of photoreceptor neurons with eventual blindness. Corrective or neuroprotective gene therapies under development could be delivered at a predegeneration stage to prevent the onset of disease, as well as at intermediate-degeneration stages to slow the rate of progression. Most preclinical gene therapy successes to date have been as predegeneration interventions. In many animal models, as well as in human studies, to date, retinal gene therapy administered well after the onset of degeneration was not able to modify the rate of progression even when successfully reversing dysfunction. We evaluated consequences of gene therapy delivered at intermediate stages of disease in a canine model of X-linked retinitis pigmentosa (XLRP) caused by a mutation in the Retinitis Pigmentosa GTPase Regulator (RPGR) gene. Spatiotemporal natural history of disease was defined and therapeutic dose selected based on predegeneration results. Then interventions were timed at earlier and later phases of intermediate-stage disease, and photoreceptor degeneration monitored with noninvasive imaging, electrophysiological function, and visual behavior for more than 2 y. All parameters showed substantial and significant arrest of the progressive time course of disease with treatment, which resulted in long-term improved retinal function and visual behavior compared with control eyes. Histology confirmed that the human RPGR transgene was stably expressed in photoreceptors and associated with improved structural preservation of rods, cones, and ON bipolar cells together with correction of opsin mislocalization. These findings in a clinically relevant large animal model demonstrate the long-term efficacy of RPGR gene augmentation and substantially broaden the therapeutic window for intervention in patients with RPGR-XLRP. PMID:26460017

  3. Evaluation of an Optimized Injection System for Retinal Gene Therapy in Human Patients.

    PubMed

    Fischer, M Dominik; Hickey, Doron G; Singh, Mandeep S; MacLaren, Robert E

    2016-08-01

    Many retinal gene therapy clinical trials require subretinal injections of small volumes of adeno-associated viral (AAV) vector solutions in patients with retinal dystrophies, using equipment not specifically designed for this purpose. We therefore evaluated an optimized injection system in order to identify variables that might influence the rate of injection and final dose of vector delivered. An optimized injection system was assembled with a 41G polytetrafluoroethylene tip for retinal gene therapy. Flow rate was recorded at relevant infusion pressures (2-22 psi [14-152 kPa]), different target pressures (0.02-30 mm Hg [0.003-4 kPa]) and temperatures (18°C vs. 36°C) using a semiautomated Accurus(®) Surgical System. Retention of AAV2/8 and AAV2/8(Y733F) vector was quantified after simulating loading/injection with or without 0.001% Pluronic(®) F-68 (PF-68). The optimized injection system provided a linear flow rate (μl/s)-to-infusion pressure (psi) relationship (y = 0.62x; r(2) = 0.99), independent of temperature and pressure changes relevant for intraocular surgery (18-36°C, 0.02-30 mm Hg). Differences in length of 41G polytetrafluoroethylene tips caused significant variation in flow rate (p < 0.001). Use of PF-68 significantly (p < 0.001) reduced loss of vector genomes in the injection system by 55% (AAV2/8) and 52% (AAV2/8(Y733F)). A customized subretinal injection system assembled using equipment currently available in the operating room can deliver a controlled volume of vector at a fixed rate across a range of possible clinical parameters encountered in vitreoretinal surgery. The inclusion of 0.001% PF-68 had a significant effect on the final dose of vector genomes delivered. The described technique is currently used successfully in a clinical trial. PMID:27480111

  4. Retinal gene therapy in patients with choroideremia: initial findings from a phase 1/2 clinical trial

    PubMed Central

    MacLaren, Robert E; Groppe, Markus; Barnard, Alun R; Cottriall, Charles L; Tolmachova, Tanya; Seymour, Len; Clark, K Reed; During, Matthew J; Cremers, Frans P M; Black, Graeme C M; Lotery, Andrew J; Downes, Susan M; Webster, Andrew R; Seabra, Miguel C

    2014-01-01

    Summary Background Choroideremia is an X-linked recessive disease that leads to blindness due to mutations in the CHM gene, which encodes the Rab escort protein 1 (REP1). We assessed the effects of retinal gene therapy with an adeno-associated viral (AAV) vector encoding REP1 (AAV.REP1) in patients with this disease. Methods In a multicentre clinical trial, six male patients (aged 35–63 years) with choroideremia were administered AAV.REP1 (0·6–1·0×1010 genome particles, subfoveal injection). Visual function tests included best corrected visual acuity, microperimetry, and retinal sensitivity tests for comparison of baseline values with 6 months after surgery. This study is registered with ClinicalTrials.gov, number NCT01461213. Findings Despite undergoing retinal detachment, which normally reduces vision, two patients with advanced choroideremia who had low baseline best corrected visual acuity gained 21 letters and 11 letters (more than two and four lines of vision). Four other patients with near normal best corrected visual acuity at baseline recovered to within one to three letters. Mean gain in visual acuity overall was 3·8 letters (SE 4·1). Maximal sensitivity measured with dark-adapted microperimetry increased in the treated eyes from 23·0 dB (SE 1·1) at baseline to 25·3 dB (1·3) after treatment (increase 2·3 dB [95% CI 0·8–3·8]). In all patients, over the 6 months, the increase in retinal sensitivity in the treated eyes (mean 1·7 [SE 1·0]) was correlated with the vector dose administered per mm2 of surviving retina (r=0·82, p=0·04). By contrast, small non-significant reductions (p>0·05) were noted in the control eyes in both maximal sensitivity (–0·8 dB [1·5]) and mean sensitivity (–1·6 dB [0·9]). One patient in whom the vector was not administered to the fovea re-established variable eccentric fixation that included the ectopic island of surviving retinal pigment epithelium that had been exposed to vector. Interpretation The

  5. Suppression and replacement gene therapy for autosomal dominant disease in a murine model of dominant retinitis pigmentosa.

    PubMed

    Millington-Ward, Sophia; Chadderton, Naomi; O'Reilly, Mary; Palfi, Arpad; Goldmann, Tobias; Kilty, Claire; Humphries, Marian; Wolfrum, Uwe; Bennett, Jean; Humphries, Peter; Kenna, Paul F; Farrar, G Jane

    2011-04-01

    For dominantly inherited disorders development of gene therapies, targeting the primary genetic lesion has been impeded by mutational heterogeneity. An example is rhodopsin-linked autosomal dominant retinitis pigmentosa with over 150 mutations in the rhodopsin gene. Validation of a mutation-independent suppression and replacement gene therapy for this disorder has been undertaken. The therapy provides a means of correcting the genetic defect in a mutation-independent manner thereby circumventing the mutational diversity. Separate adeno-associated virus (AAV) vectors were used to deliver an RNA interference (RNAi)-based rhodopsin suppressor and a codon-modified rhodopsin replacement gene resistant to suppression due to nucleotide alterations at degenerate positions over the RNAi target site. Viruses were subretinally coinjected into P347S mice, a model of dominant rhodopsin-linked retinitis pigmentosa. Benefit in retinal function and structure detected by electroretinography (ERG) and histology, respectively, was observed for at least 5 months. Notably, the photoreceptor cell layer, absent in 5-month-old untreated retinas, contained 3-4 layers of nuclei, whereas photoreceptor ultrastructure, assessed by transmission electron microscopy (TEM) improved significantly. The study provides compelling evidence that codelivered suppression and replacement is beneficial, representing a significant step toward the clinic. Additionally, dual-vector delivery of combined therapeutics represents an exciting approach, which is potentially applicable to other inherited disorders. PMID:21224835

  6. Gene therapy provides long-term visual function in a pre-clinical model of retinitis pigmentosa

    PubMed Central

    Wert, Katherine J.; Davis, Richard J.; Sancho-Pelluz, Javier; Nishina, Patsy M.; Tsang, Stephen H.

    2013-01-01

    Approximately 36 000 cases of simplex and familial retinitis pigmentosa (RP) worldwide are caused by a loss in phosphodiesterase (PDE6) function. In the preclinical Pde6αnmf363 mouse model of this disease, defects in the α-subunit of PDE6 result in a progressive loss of photoreceptors and neuronal function. We hypothesized that increasing PDE6α levels using an AAV2/8 gene therapy vector could improve photoreceptor survival and retinal function. We utilized a vector with the cell-type-specific rhodopsin (RHO) promoter: AAV2/8(Y733F)-Rho-Pde6α, to transduce Pde6αnmf363 retinas and monitored its effects over a 6-month period (a quarter of the mouse lifespan). We found that a single injection enhanced survival of photoreceptors and improved retinal function. At 6 months of age, the treated eyes retained photoreceptor cell bodies, while there were no detectable photoreceptors remaining in the untreated eyes. More importantly, the treated eyes demonstrated functional visual responses even after the untreated eyes had lost all vision. Despite focal rescue of the retinal structure adjacent to the injection site, global functional rescue of the entire retina was observed. These results suggest that RP due to PDE6α deficiency in humans, in addition to PDE6β deficiency, is also likely to be treatable by gene therapy. PMID:23108158

  7. Gene therapy provides long-term visual function in a pre-clinical model of retinitis pigmentosa.

    PubMed

    Wert, Katherine J; Davis, Richard J; Sancho-Pelluz, Javier; Nishina, Patsy M; Tsang, Stephen H

    2013-02-01

    Approximately 36 000 cases of simplex and familial retinitis pigmentosa (RP) worldwide are caused by a loss in phosphodiesterase (PDE6) function. In the preclinical Pde6α(nmf363) mouse model of this disease, defects in the α-subunit of PDE6 result in a progressive loss of photoreceptors and neuronal function. We hypothesized that increasing PDE6α levels using an AAV2/8 gene therapy vector could improve photoreceptor survival and retinal function. We utilized a vector with the cell-type-specific rhodopsin (RHO) promoter: AAV2/8(Y733F)-Rho-Pde6α, to transduce Pde6α(nmf363) retinas and monitored its effects over a 6-month period (a quarter of the mouse lifespan). We found that a single injection enhanced survival of photoreceptors and improved retinal function. At 6 months of age, the treated eyes retained photoreceptor cell bodies, while there were no detectable photoreceptors remaining in the untreated eyes. More importantly, the treated eyes demonstrated functional visual responses even after the untreated eyes had lost all vision. Despite focal rescue of the retinal structure adjacent to the injection site, global functional rescue of the entire retina was observed. These results suggest that RP due to PDE6α deficiency in humans, in addition to PDE6β deficiency, is also likely to be treatable by gene therapy. PMID:23108158

  8. Hypotrichosis and juvenile macular dystrophy caused by CDH3 mutation: A candidate disease for retinal gene therapy

    PubMed Central

    Singh, Mandeep S.; Broadgate, Suzanne; Mathur, Ranjana; Holt, Richard; Halford, Stephanie; MacLaren, Robert E.

    2016-01-01

    Hypotrichosis with juvenile macular dystrophy (HJMD) is an autosomal recessive disorder that causes childhood visual impairment. HJMD is caused by mutations in CDH3 which encodes cadherin-3, a protein expressed in retinal pigment epithelium (RPE) cells that may have a key role in intercellular adhesion. We present a case of HJMD and analyse its phenotypic and molecular characteristics to assess the potential for retinal gene therapy as a means of preventing severe visual loss in this condition. Longitudinal in vivo imaging of the retina showed the relative anatomical preservation of the macula, which suggested the presence of a therapeutic window for gene augmentation therapy to preserve visual acuity. The coding sequence of CDH3 fits within the packaging limit of recombinant adeno-associated virus vectors that have been shown to be safe in clinical trials and can efficiently target RPE cells. This report expands the number of reported cases of HJMD and highlights the phenotypic characteristics to consider when selecting candidates for retinal gene therapy. PMID:27157923

  9. Hypotrichosis and juvenile macular dystrophy caused by CDH3 mutation: A candidate disease for retinal gene therapy.

    PubMed

    Singh, Mandeep S; Broadgate, Suzanne; Mathur, Ranjana; Holt, Richard; Halford, Stephanie; MacLaren, Robert E

    2016-01-01

    Hypotrichosis with juvenile macular dystrophy (HJMD) is an autosomal recessive disorder that causes childhood visual impairment. HJMD is caused by mutations in CDH3 which encodes cadherin-3, a protein expressed in retinal pigment epithelium (RPE) cells that may have a key role in intercellular adhesion. We present a case of HJMD and analyse its phenotypic and molecular characteristics to assess the potential for retinal gene therapy as a means of preventing severe visual loss in this condition. Longitudinal in vivo imaging of the retina showed the relative anatomical preservation of the macula, which suggested the presence of a therapeutic window for gene augmentation therapy to preserve visual acuity. The coding sequence of CDH3 fits within the packaging limit of recombinant adeno-associated virus vectors that have been shown to be safe in clinical trials and can efficiently target RPE cells. This report expands the number of reported cases of HJMD and highlights the phenotypic characteristics to consider when selecting candidates for retinal gene therapy. PMID:27157923

  10. Low molecular weight oligochitosans for non-viral retinal gene therapy.

    PubMed

    Puras, G; Zarate, J; Aceves, M; Murua, A; Díaz, A R; Avilés-Triguero, M; Fernández, E; Pedraz, J L

    2013-02-01

    Ultrapure oligochitosans have recently been evaluated as a promising tool for corneal gene therapy; however, there are no reports regarding the potential use of this polymer in other ocular tissues. We have prepared and characterized at pH 7.1 oligochitosan/pCMS-EGFP polyplexes to evaluate the transfection efficiency in rat retinas after subretinal and intravitreal administration. Polyplexes were characterized in terms of shape, size, surface charge, DNA condensation, and transfection efficiency in HEK-293 and ARPE-19 culture cells. Polyplexes were positively charged, around 10 mV, and size oscillated between 256.5 ± 56 and 67.3 ± 0.44 nm, depending on the nitrogenous/phosphate ratio. Polyplexes efficiently protected the plasmid against enzymatic digestion. A drastic increase in transfection efficiency was observed when pH slightly decreased from 7.4 to 7.1 in both HEK-293 (from 19.1% to 51.5%) and ARPE-19 (from 2.0% to 36.5%) cells (data normalized to Lipofectamine™ 2000). In rat retinas, subretinal administrations transfected cells mainly in the RPE layer, whereas intravitreal injections transfected cells in the inner nuclear and plexiform layers of the retina and mainly in the ganglion cell layer. This study establishes the base for future treatments of genetic retinal disorders with low molecular weight oligochitosan polyplexes. PMID:23059418

  11. Gene Augmentation Therapy Restores Retinal Function and Visual Behavior in a Sheep Model of CNGA3 Achromatopsia.

    PubMed

    Banin, Eyal; Gootwine, Elisha; Obolensky, Alexey; Ezra-Elia, Raaya; Ejzenberg, Ayala; Zelinger, Lina; Honig, Hen; Rosov, Alexander; Yamin, Esther; Sharon, Dror; Averbukh, Edward; Hauswirth, William W; Ofri, Ron

    2015-09-01

    Achromatopsia is a hereditary form of day blindness caused by cone photoreceptor dysfunction. Affected patients suffer from congenital color blindness, photosensitivity, and low visual acuity. Mutations in the CNGA3 gene are a major cause of achromatopsia, and a sheep model of this disease was recently characterized by our group. Here, we report that unilateral subretinal delivery of an adeno-associated virus serotype 5 (AAV5) vector carrying either the mouse or the human intact CNGA3 gene under the control of the red/green opsin promoter results in long-term recovery of visual function in CNGA3-mutant sheep. Treated animals demonstrated shorter maze passage times and a reduced number of collisions with obstacles compared with their pretreatment status, with values close to those of unaffected sheep. This effect was abolished when the treated eye was patched. Electroretinography (ERG) showed marked improvement in cone function. Retinal expression of the transfected human and mouse CNGA3 genes at the mRNA level was shown by polymerase chain reaction (PCR), and cone-specific expression of CNGA3 protein was demonstrated by immunohistochemisrty. The rescue effect has so far been maintained for over 3 years in the first-treated animals, with no obvious ocular or systemic side effects. The results support future application of subretinal AAV5-mediated gene-augmentation therapy in CNGA3 achromatopsia patients. PMID:26087757

  12. Gene Augmentation Therapy Restores Retinal Function and Visual Behavior in a Sheep Model of CNGA3 Achromatopsia

    PubMed Central

    Banin, Eyal; Gootwine, Elisha; Obolensky, Alexey; Ezra-Elia, Raaya; Ejzenberg, Ayala; Zelinger, Lina; Honig, Hen; Rosov, Alexander; Yamin, Esther; Sharon, Dror; Averbukh, Edward; Hauswirth, William W; Ofri, Ron

    2015-01-01

    Achromatopsia is a hereditary form of day blindness caused by cone photoreceptor dysfunction. Affected patients suffer from congenital color blindness, photosensitivity, and low visual acuity. Mutations in the CNGA3 gene are a major cause of achromatopsia, and a sheep model of this disease was recently characterized by our group. Here, we report that unilateral subretinal delivery of an adeno-associated virus serotype 5 (AAV5) vector carrying either the mouse or the human intact CNGA3 gene under the control of the red/green opsin promoter results in long-term recovery of visual function in CNGA3-mutant sheep. Treated animals demonstrated shorter maze passage times and a reduced number of collisions with obstacles compared with their pretreatment status, with values close to those of unaffected sheep. This effect was abolished when the treated eye was patched. Electroretinography (ERG) showed marked improvement in cone function. Retinal expression of the transfected human and mouse CNGA3 genes at the mRNA level was shown by polymerase chain reaction (PCR), and cone-specific expression of CNGA3 protein was demonstrated by immunohistochemisrty. The rescue effect has so far been maintained for over 3 years in the first-treated animals, with no obvious ocular or systemic side effects. The results support future application of subretinal AAV5-mediated gene-augmentation therapy in CNGA3 achromatopsia patients. PMID:26087757

  13. CNTF Gene Therapy Confers Lifelong Neuroprotection in a Mouse Model of Human Retinitis Pigmentosa.

    PubMed

    Lipinski, Daniel M; Barnard, Alun R; Singh, Mandeep S; Martin, Chris; Lee, Edward J; Davies, Wayne I L; MacLaren, Robert E

    2015-08-01

    The long-term outcome of neuroprotection as a therapeutic strategy for preventing cell death in neurodegenerative disorders remains unknown, primarily due to slow disease progression and the inherent difficulty of assessing neuronal survival in vivo. Employing a murine model of retinal disease, we demonstrate that ciliary neurotrophic factor (CNTF) confers life-long protection against photoreceptor degeneration. Repetitive retinal imaging allowed the survival of intrinsically fluorescent cone photoreceptors to be quantified in vivo. Imaging of the visual cortex and assessment of visually-evoked behavioral responses demonstrated that surviving cones retain function and signal correctly to the brain. The mechanisms underlying CNTF-mediated neuroprotection were explored through transcriptome analysis, revealing widespread upregulation of proteolysis inhibitors, which may prevent cellular/extracellular matrix degradation and complement activation in neurodegenerative diseases. These findings provide insights into potential novel therapeutic avenues for diseases such as retinitis pigmentosa and amyotrophic lateral sclerosis, for which CNTF has been evaluated unsuccessfully in clinical trials. PMID:25896245

  14. Antisense Oligonucleotide Therapy for Inherited Retinal Dystrophies.

    PubMed

    Gerard, Xavier; Garanto, Alejandro; Rozet, Jean-Michel; Collin, Rob W J

    2016-01-01

    Inherited retinal dystrophies (IRDs) are an extremely heterogeneous group of genetic diseases for which currently no effective treatment strategies exist. Over the last decade, significant progress has been made utilizing gene augmentation therapy for a few genetic subtypes of IRD, although several technical challenges so far prevent a broad clinical application of this approach for other forms of IRD. Many of the mutations leading to these retinal diseases affect pre-mRNA splicing of the mutated genes . Antisense oligonucleotide (AON)-mediated splice modulation appears to be a powerful approach to correct the consequences of such mutations at the pre-mRNA level , as demonstrated by promising results in clinical trials for several inherited disorders like Duchenne muscular dystrophy, hypercholesterolemia and various types of cancer. In this mini-review, we summarize ongoing pre-clinical research on AON-based therapy for a few genetic subtypes of IRD , speculate on other potential therapeutic targets, and discuss the opportunities and challenges that lie ahead to translate splice modulation therapy for retinal disorders to the clinic. PMID:26427454

  15. The Signalling Role of the αvβ5-Integrin Can Impact the Efficacy of AAV in Retinal Gene Therapy

    PubMed Central

    Cronin, Therese; Chung, Daniel C.; Yang, Ying; Nandrot, Emeline F.; Bennett, Jean

    2012-01-01

    Sub-retinal injection of the common AAV2 pseudotypes frequently results in strong transduction of the retinal pigment epithelium (RPE) as well as the retina itself. This has been of benefit to date in human clinical trials using AAV, where the disease target is in the RPE. However, many mutations predisposing to retinal disease are located in the photoreceptor cells, present in the neural retina and not the RPE; in this case the sub-retinal injection route may cause an effective “loss” of therapeutic AAV to the RPE. The αvβ5 integrin receptor is highly expressed on the apical surface of the RPE, and is essential to the daily phagocytosis of the outer segment tips of photoreceptor cells. The transduction efficiency of AAV was tested in the retinas of β5−/− mice lacking this receptor and showing defects in photoreceptor outer segment phagocytosis. Following sub-retinal injection of AAV2/5-eGFP, fluorescence was found to be stronger and more widespread in the neural retina of β5−/− mice compared to wild-types with greatly reduced fluorescence in the RPE. Increased levels of the phagocytic signalling protein MFG-E8, the ligand for the αvβ5 integrin receptor, is found to have a moderate inhibitory effect on AAV transduction of the retina. However the opposite effect is found when only the integrin-binding domain of MFG-E8, the RGD (Arginine-Glycine-Aspartic acid) domain, was increased. In this case RGD enhanced AAV-mediated retinal transduction relative to RPE transduction. These results are presented for their relevance for the design of AAV-based retinal gene therapy strategies strategies targeting retinal/photoreceptor cells. PMID:24281556

  16. CNTF gene therapy confers lifelong neuroprotection in a mouse model of human retinitis pigmentosa

    PubMed Central

    Lipinski, Daniel M.; Barnard, Alun R.; Singh, Mandeep S.; Martin, Chris; Lee, Edward; Davies, Wayne I.L.; MacLaren, Robert E.

    2015-01-01

    The long-term outcome of neuroprotection as a therapeutic strategy for preventing cell death in neurodegenerative disorders remains unknown, primarily due to slow disease progression and the inherent difficulty of assessing neuronal survival in vivo. Employing a murine model of retinal disease, we demonstrate that ciliary neurotrophic factor (CNTF) confers life-long protection against photoreceptor degeneration. Repetitive retinal imaging allowed the survival of intrinsically fluorescent cone photoreceptors to be quantified in vivo. Imaging of the visual cortex and assessment of visually-evoked behavioural responses demonstrated that surviving cones retain function and signal correctly to the brain. The mechanisms underlying CNTF-mediated neuroprotection were explored through transcriptome analysis, revealing widespread up-regulation of proteolysis inhibitors, which may prevent cellular/extracellular matrix degradation and complement activation in neurodegenerative diseases. These findings provide insights into potential novel therapeutic avenues for diseases such as retinitis pigmentosa and amyotrophic lateral sclerosis, for which CNTF has been evaluated unsuccessfully in clinical trials. PMID:25896245

  17. A Hypoxia-Responsive Glial Cell–Specific Gene Therapy Vector for Targeting Retinal Neovascularization

    PubMed Central

    Biswal, Manas R.; Prentice, Howard M.; Dorey, C. Kathleen; Blanks, Janet C.

    2014-01-01

    Purpose. Müller cells, the major glial cell in the retina, play a significant role in retinal neovascularization in response to tissue hypoxia. We previously designed and tested a vector using a hypoxia-responsive domain and a glial fibrillary acidic protein (GFAP) promoter to drive green fluorescent protein (GFP) expression in Müller cells in the murine model of oxygen-induced retinopathy (OIR). This study compares the efficacy of regulated and unregulated Müller cell delivery of endostatin in preventing neovascularization in the OIR model. Methods. Endostatin cDNA was cloned into plasmids with hypoxia-regulated GFAP or unregulated GFAP promoters, and packaged into self-complementary adeno-associated virus serotype 2 vectors (scAAV2). Before placement in hyperoxia on postnatal day (P)7, mice were given intravitreal injections of regulated or unregulated scAAV2, capsid, or PBS. Five days after return to room air, on P17, neovascular and avascular areas, as well as expression of the transgene and vascular endothelial growth factor (VEGF), were compared in OIR animals treated with a vector, capsid, or PBS. Results. The hypoxia-regulated, glial-specific, vector-expressing endostatin reduced neovascularization by 93% and reduced the central vaso-obliteration area by 90%, matching the results with the unregulated GFAP-Endo vector. Retinas treated with the regulated endostatin vector expressed substantial amounts of endostatin protein, and significantly reduced VEGF protein. Endostatin production from the regulated vector was undetectable in retinas with undamaged vasculature. Conclusions. These findings suggest that the hypoxia-regulated, glial cell–specific vector expressing endostatin may be useful for treatment of neovascularization in proliferative diabetic retinopathy. PMID:25377223

  18. Intracerebroventricular gene therapy that delays neurological disease progression is associated with selective preservation of retinal ganglion cells in a canine model of CLN2 disease.

    PubMed

    Whiting, Rebecca E H; Jensen, Cheryl A; Pearce, Jacqueline W; Gillespie, Lauren E; Bristow, Daniel E; Katz, Martin L

    2016-05-01

    CLN2 disease is one of a group of lysosomal storage disorders called the neuronal ceroid lipofuscinoses (NCLs). The disease results from mutations in the TPP1 gene that cause an insufficiency or complete lack of the soluble lysosomal enzyme tripeptidyl peptidase-1 (TPP1). TPP1 is involved in lysosomal protein degradation, and lack of this enzyme results in the accumulation of protein-rich autofluorescent lysosomal storage bodies in numerous cell types including neurons throughout the central nervous system and the retina. CLN2 disease is characterized primarily by progressive loss of neurological functions and vision as well as generalized neurodegeneration and retinal degeneration. In children the progressive loss of neurological functions typically results in death by the early teenage years. A Dachshund model of CLN2 disease with a null mutation in TPP1 closely recapitulates the human disorder with a progression from disease onset at approximately 4 months of age to end-stage at 10-11 months. Delivery of functional TPP1 to the cerebrospinal fluid (CSF), either by periodic infusion of the recombinant protein or by a single administration of a TPP1 gene therapy vector to the CSF, significantly delays the onset and progression of neurological signs and prolongs life span but does not prevent the loss of vision or modest retinal degeneration that occurs by 11 months of age. In this study we found that in dogs that received the CSF gene therapy treatment, the degeneration of the retina and loss of retinal function continued to progress during the prolonged life spans of the treated dogs. Eventually the normal cell layers of the retina almost completely disappeared. An exception was the ganglion cell layer. In affected dogs that received TPP1 gene therapy to the CSF and survived an average of 80 weeks, ganglion cell axons were present in numbers comparable to those of normal Dachshunds of similar age. The selective preservation of the retinal ganglion cells suggests

  19. Intracerebroventricular gene therapy that delays neurological disease progression is associated with selective preservation of retinal ganglion cells in a canine model of CLN2 disease

    PubMed Central

    Whiting, Rebecca E.H.; Jensen, Cheryl A.; Pearce, Jacqueline W.; Gillespie, Lauren E.; Bristow, Daniel E.; Katz, Martin L.

    2016-01-01

    CLN2 disease is one of a group of lysosomal storage disorders called the neuronal ceroid lipofuscinoses (NCLs). The disease results from mutations in the TPP1 gene that cause an insufficiency or complete lack of the soluble lysosomal enzyme tripeptidyl peptidase-1 (TPP1). TPP1 is involved in lysosomal protein degradation, and lack of this enzyme results in the accumulation of protein-rich autofluorescent lysosomal storage bodies in numerous cell types including neurons throughout the central nervous system and the retina. CLN2 disease is characterized primarily by progressive loss of neurological functions and vision as well as generalized neurodegeneration and retinal degeneration. In children the progressive loss of neurological functions typically results in death by the early teenage years. A Dachshund model of CLN2 disease with a null mutation in TPP1 closely recapitulates the human disorder with a progression from disease onset at approximately 4 months of age to end-stage at 10–11 months. Delivery of functional TPP1 to the cerebrospinal fluid (CSF), either by periodic infusion of the recombinant protein or by a single administration of a TPP1 gene therapy vector to the CSF, significantly delays the onset and progression of neurological signs and prolongs life span but does not prevent the loss of vision or modest retinal degeneration that occurs by 11 months of age. In this study we found that in dogs that received the CSF gene therapy treatment, the degeneration of the retina and loss of retinal function continued to progress during the prolonged life spans of the treated dogs. Eventually the normal cell layers of the retina almost completely disappeared. An exception was the ganglion cell layer. In affected dogs that received TPP1 gene therapy to the CSF and survived an average of 80 weeks, ganglion cell axons were present in numbers comparable to those of normal Dachshunds of similar age. The selective preservation of the retinal ganglion cells suggests

  20. Safety and Efficacy of Suicide Gene Therapy with Adenosine Deaminase 5-Fluorocytosine Silmutaneously in in Vitro Cultures of Melanoma and Retinal Cell Lines

    PubMed Central

    Sakkas, Antonios; Zarogoulidis, Paul; Domvri, Kalliopi; Hohenforst-Schmidt, Wolfgang; Bougiouklis, Dimitris; Kakolyris, Stylianos; Zarampoukas, Thomas; Kioumis, Ioannis; Pitsiou, Georgia; Huang, Haidong; Li, Qiang; Meditskou, Soultana; Tsiouda, Theodora; Pezirkianidis, Nikolaos; Zarogoulidis, Konstantinos

    2014-01-01

    Local treatment as a treatment modality is gaining increased general acceptance over time. Novel drugs and methodologies of local administration are being investigated in an effort to achieve disease local control. Suicide gene therapy is a method that has been investigated as a local treatment with simultaneously distant disease control. In our current experiment we purchased HTB-70 (melanoma cell line, derived from metastatic axillary node) and CRL-2302 (human retinal epithelium) were from ATCC LGC Standards and Ancotil®, 2.5 g/250 ml (1 g/00ml) (5-Flucytosine) MEDA; Pharmaceuticals Ltd. UK. Adenosine Cytosine Deaminase (Ad.CD) was also used in order to convert the pro-drug 5-Flucytosine to the active 5-Fluoracil. Three different concentrations of 5-Flucytosine (5-FC) were administered (0.2ml, 0.8ml and 1.2ml). At indicated time-points (4h, 8h and 24h) cell viability and apoptosis were measured. Our concept was to investigate whether suicide gene therapy with Ad. CD-5-FC could be used with safety and efficiency as a future local treatment for melanoma located in the eye cavity. Indeed, our results indicated that in every 5-FC administration had mild cytotoxicity for the retinal cells, while increased apoptosis was observed for the melanoma cell line. PMID:24799955

  1. Safety and efficacy of suicide gene therapy with adenosine deaminase 5-fluorocytosine silmutaneously in in vitro cultures of melanoma and retinal cell lines.

    PubMed

    Sakkas, Antonios; Zarogoulidis, Paul; Domvri, Kalliopi; Hohenforst-Schmidt, Wolfgang; Bougiouklis, Dimitris; Kakolyris, Stylianos; Zarampoukas, Thomas; Kioumis, Ioannis; Pitsiou, Georgia; Huang, Haidong; Li, Qiang; Meditskou, Soultana; Tsiouda, Theodora; Pezirkianidis, Nikolaos; Zarogoulidis, Konstantinos

    2014-01-01

    Local treatment as a treatment modality is gaining increased general acceptance over time. Novel drugs and methodologies of local administration are being investigated in an effort to achieve disease local control. Suicide gene therapy is a method that has been investigated as a local treatment with simultaneously distant disease control. In our current experiment we purchased HTB-70 (melanoma cell line, derived from metastatic axillary node) and CRL-2302 (human retinal epithelium) were from ATCC LGC Standards and Ancotil(®), 2.5 g/250 ml (1 g/00ml) (5-Flucytosine) MEDA; Pharmaceuticals Ltd. UK. Adenosine Cytosine Deaminase (Ad.CD) was also used in order to convert the pro-drug 5-Flucytosine to the active 5-Fluoracil. Three different concentrations of 5-Flucytosine (5-FC) were administered (0.2ml, 0.8ml and 1.2ml). At indicated time-points (4h, 8h and 24h) cell viability and apoptosis were measured. Our concept was to investigate whether suicide gene therapy with Ad. CD-5-FC could be used with safety and efficiency as a future local treatment for melanoma located in the eye cavity. Indeed, our results indicated that in every 5-FC administration had mild cytotoxicity for the retinal cells, while increased apoptosis was observed for the melanoma cell line. PMID:24799955

  2. Genes and Gene Therapy

    MedlinePlus

    ... a child can have a genetic disorder. Gene therapy is an experimental technique that uses genes to ... prevent disease. The most common form of gene therapy involves inserting a normal gene to replace an ...

  3. Genes and Gene Therapy

    MedlinePlus

    ... correctly, a child can have a genetic disorder. Gene therapy is an experimental technique that uses genes to ... or prevent disease. The most common form of gene therapy involves inserting a normal gene to replace an ...

  4. Mid-stage intervention achieves similar efficacy as conventional early-stage treatment using gene therapy in a pre-clinical model of retinitis pigmentosa

    PubMed Central

    Wert, Katherine J.; Sancho-Pelluz, Javier; Tsang, Stephen H.

    2014-01-01

    Deficiencies in rod-specific cyclic guanosine monophosphate (cGMP) phosphodiesterase-6 (PDE6) are the third most common cause of autosomal recessive retinitis pigmentosa (RP). Previously, viral gene therapy approaches on pre-clinical models with mutations in PDE6 have demonstrated that the photoreceptor cell survival and visual function can be rescued when the gene therapy virus is delivered into the subretinal space before the onset of disease. However, no studies have currently been published that analyze rescue effects after disease onset, a time when human RP patients are diagnosed by a clinician and would receive the treatment. We utilized the AAV2/8(Y733F)-Rho-Pde6α gene therapy virus and injected it into a pre-clinical model of RP with a mutation within the alpha subunit of PDE6: Pde6αD670G. These mice were previously shown to have long-term photoreceptor cell rescue when this gene therapy virus was delivered before the onset of disease. Now, we have determined that subretinal transduction of this rod-specific transgene at post-natal day (P) 21, when approximately half of the photoreceptor cells have undergone degeneration, is more efficient in rescuing cone than rod photoreceptor function long term. Therefore, AAV2/8(Y733F)-Rho-Pde6α is an effective gene therapy treatment that can be utilized in the clinical setting, in human patients who have lost portions of their peripheral visual field and are in the mid-stage of disease when they first present to an eye-care professional. PMID:24101599

  5. Mid-stage intervention achieves similar efficacy as conventional early-stage treatment using gene therapy in a pre-clinical model of retinitis pigmentosa.

    PubMed

    Wert, Katherine J; Sancho-Pelluz, Javier; Tsang, Stephen H

    2014-01-15

    Deficiencies in rod-specific cyclic guanosine monophosphate (cGMP) phosphodiesterase-6 (PDE6) are the third most common cause of autosomal recessive retinitis pigmentosa (RP). Previously, viral gene therapy approaches on pre-clinical models with mutations in PDE6 have demonstrated that the photoreceptor cell survival and visual function can be rescued when the gene therapy virus is delivered into the subretinal space before the onset of disease. However, no studies have currently been published that analyze rescue effects after disease onset, a time when human RP patients are diagnosed by a clinician and would receive the treatment. We utilized the AAV2/8(Y733F)-Rho-Pde6α gene therapy virus and injected it into a pre-clinical model of RP with a mutation within the alpha subunit of PDE6: Pde6α(D670G). These mice were previously shown to have long-term photoreceptor cell rescue when this gene therapy virus was delivered before the onset of disease. Now, we have determined that subretinal transduction of this rod-specific transgene at post-natal day (P) 21, when approximately half of the photoreceptor cells have undergone degeneration, is more efficient in rescuing cone than rod photoreceptor function long term. Therefore, AAV2/8(Y733F)-Rho-Pde6α is an effective gene therapy treatment that can be utilized in the clinical setting, in human patients who have lost portions of their peripheral visual field and are in the mid-stage of disease when they first present to an eye-care professional. PMID:24101599

  6. Gene Therapy

    PubMed Central

    Baum, Bruce J

    2014-01-01

    Applications of gene therapy have been evaluated in virtually every oral tissue, and many of these have proved successful at least in animal models. While gene therapy will not be used routinely in the next decade, practitioners of oral medicine should be aware of the potential of this novel type of treatment that doubtless will benefit many patients with oral diseases. PMID:24372817

  7. Prospects for gene therapy.

    PubMed

    Ali, Robin R

    2004-01-01

    Inherited retinal disease, which includes conditions such as retinitis pigmentosa (RP), affects about 1/3000 of the population in the Western world. It is characterized by gradual loss of vision and results from mutations in any one of 60 or so different genes. There are currently no effective treatments, but many of the genes have now been identified and their functions elucidated, providing a major impetus to develop gene-based treatments. Many of the disease genes are photoreceptor- or retinal pigment epithelium (RPE) cell specific. Since adeno-associated viral (AAV) vectors can be used for efficient gene transfer to these two cell types, we are developing AAV-mediated gene therapy approaches for inherited retinal degeneration using animal models that have defects in these cells. The retinal degeneration slow (rds or Prph2Rd2/Rd) mouse, a model of recessive RP, lacks a functional gene encoding peripherin 2, which is a photoreceptor-specific protein required for the formation of outer segment discs. We have previously demonstrated restoration of photoreceptor ultrastructure and function by AAV-mediated gene transfer of peripherin 2. We have now extended our assessment to central visual neuronal responses in order to show an improvement of central visual function. The Royal College of Surgeons (RCS) rat, provides another model of recessive RP. Here the defect is due to a defect in Mertk, a gene that is expressed in the RPE and encodes a receptor tyrosine kinase that is thought to be involved in the recognition and binding of outer segment debris. The gene defect results in the inability of the RPE to phagocytose the shed outer segments from photoreceptor cells. The resulting accumulation of debris between the RPE and the neuroretina leads to progressive loss of photoreceptor cells. AAV-mediated delivery of Mertk to the RPE results in reduction of debris indicating that the phagocytosing function of the RPE is restored and delays the degeneration of the

  8. Retinal dystrophies, genomic applications in diagnosis and prospects for therapy.

    PubMed

    Nash, Benjamin M; Wright, Dale C; Grigg, John R; Bennetts, Bruce; Jamieson, Robyn V

    2015-04-01

    Retinal dystrophies (RDs) are degenerative diseases of the retina which have marked clinical and genetic heterogeneity. Common presentations among these disorders include night or colour blindness, tunnel vision and subsequent progression to complete blindness. The known causative disease genes have a variety of developmental and functional roles with mutations in more than 120 genes shown to be responsible for the phenotypes. In addition, mutations within the same gene have been shown to cause different disease phenotypes, even amongst affected individuals within the same family highlighting further levels of complexity. The known disease genes encode proteins involved in retinal cellular structures, phototransduction, the visual cycle, and photoreceptor structure or gene regulation. This review aims to demonstrate the high degree of genetic complexity in both the causative disease genes and their associated phenotypes, highlighting the more common clinical manifestation of retinitis pigmentosa (RP). The review also provides insight to recent advances in genomic molecular diagnosis and gene and cell-based therapies for the RDs. PMID:26835369

  9. Developing Cellular Therapies for Retinal Degenerative Diseases

    PubMed Central

    Bharti, Kapil; Rao, Mahendra; Hull, Sara Chandros; Stroncek, David; Brooks, Brian P.; Feigal, Ellen; van Meurs, Jan C.; Huang, Christene A.; Miller, Sheldon S.

    2014-01-01

    Biomedical advances in vision research have been greatly facilitated by the clinical accessibility of the visual system, its ease of experimental manipulation, and its ability to be functionally monitored in real time with noninvasive imaging techniques at the level of single cells and with quantitative end-point measures. A recent example is the development of stem cell–based therapies for degenerative eye diseases including AMD. Two phase I clinical trials using embryonic stem cell–derived RPE are already underway and several others using both pluripotent and multipotent adult stem cells are in earlier stages of development. These clinical trials will use a variety of cell types, including embryonic or induced pluripotent stem cell–derived RPE, bone marrow– or umbilical cord–derived mesenchymal stem cells, fetal neural or retinal progenitor cells, and adult RPE stem cells–derived RPE. Although quite distinct, these approaches, share common principles, concerns and issues across the clinical development pipeline. These considerations were a central part of the discussions at a recent National Eye Institute meeting on the development of cellular therapies for retinal degenerative disease. At this meeting, emphasis was placed on the general value of identifying and sharing information in the so-called “precompetitive space.” The utility of this behavior was described in terms of how it could allow us to remove road blocks in the clinical development pipeline, and more efficiently and economically move stem cell–based therapies for retinal degenerative diseases toward the clinic. Many of the ocular stem cell approaches we discuss are also being used more broadly, for nonocular conditions and therefore the model we develop here, using the precompetitive space, should benefit the entire scientific community. PMID:24573369

  10. Gene expression changes during retinal development and rod specification

    PubMed Central

    Carrigan, Matthew; Hokamp, Karsten; Farrar, G. Jane

    2015-01-01

    Purpose Retinitis pigmentosa (RP) typically results from individual mutations in any one of >70 genes that cause rod photoreceptor cells to degenerate prematurely, eventually resulting in blindness. Gene therapies targeting individual RP genes have shown efficacy at clinical trial; however, these therapies require the surviving photoreceptor cells to be viable and functional, and may be economically feasible for only the more commonly mutated genes. An alternative potential treatment strategy, particularly for late stage disease, may involve stem cell transplants into the photoreceptor layer of the retina. Rod progenitors from postnatal mouse retinas can be transplanted and can form photoreceptors in recipient adult retinas; optimal numbers of transplantable cells are obtained from postnatal day 3–5 (P3–5) retinas. These cells can also be expanded in culture; however, this results in the loss of photoreceptor potential. Gene expression differences between postnatal retinas, cultured retinal progenitor cells (RPCs), and rod photoreceptor precursors were investigated to identify gene expression patterns involved in the specification of rod photoreceptors. Methods Microarrays were used to investigate differences in gene expression between cultured RPCs that have lost photoreceptor potential, P1 retinas, and fresh P5 retinas that contain significant numbers of transplantable photoreceptors. Additionally, fluorescence-activated cell sorting (FACS) sorted Rho-eGFP-expressing rod photoreceptor precursors were compared with Rho-eGFP-negative cells from the same P5 retinas. Differential expression was confirmed with quantitative polymerase chain reaction (q-PCR). Results Analysis of the microarray data sets, including the use of t-distributed stochastic neighbor embedding (t-SNE) to identify expression pattern neighbors of key photoreceptor specific genes, resulted in the identification of 636 genes differentially regulated during rod specification. Forty-four of these

  11. Preclinical Dose-Escalation Study of Intravitreal AAV-RS1 Gene Therapy in a Mouse Model of X-linked Retinoschisis: Dose-Dependent Expression and Improved Retinal Structure and Function.

    PubMed

    Bush, Ronald A; Zeng, Yong; Colosi, Peter; Kjellstrom, Sten; Hiriyanna, Suja; Vijayasarathy, Camasamudram; Santos, Maria; Li, Jinbo; Wu, Zhijian; Sieving, Paul A

    2016-05-01

    Gene therapy for inherited retinal diseases has been shown to ameliorate functional and structural defects in both animal models and in human clinical trials. X-linked retinoschisis (XLRS) is an early-age onset macular dystrophy resulting from loss of an extracellular matrix protein (RS1). In preparation for a human clinical gene therapy trial, we conducted a dose-range efficacy study of the clinical vector, a self-complementary AAV delivering a human retinoschisin (RS1) gene under control of the RS1 promoter and an interphotoreceptor binding protein enhancer (AAV8-scRS/IRBPhRS), in the retinoschisin knockout (Rs1-KO) mouse. The therapeutic vector at 1 × 10(6) to 2.5 × 10(9) (1E6-2.5E9) vector genomes (vg)/eye or vehicle was administered to one eye of 229 male Rs1-KO mice by intravitreal injection at 22 ± 3 days postnatal age (PN). Analysis of retinal function (dark-adapted electroretinogram, ERG), structure (cavities and outer nuclear layer thickness) by in vivo retinal imaging using optical coherence tomography, and retinal immunohistochemistry (IHC) for RS1 was done 3-4 months and/or 6-9 months postinjection (PI). RS1 IHC staining was dose dependent across doses ≥1E7 vg/eye, and the threshold for significant improvement in all measures of retinal structure and function was 1E8 vg/eye. Higher doses, however, did not produce additional improvement. At all doses showing efficacy, RS1 staining in Rs1-KO mouse was less than that in wild-type mice. Improvement in the ERG and RS1 staining was unchanged or greater at 6-9 months than at 3-4 months PI. This study demonstrates that vitreal administration of AAV8 scRS/IRBPhRS produces significant improvement in retinal structure and function in the mouse model of XLRS over a vector dose range that can be extended to a human trial. It indicates that a fully normal level of RS1 expression is not necessary for a therapeutic effect. PMID:27036983

  12. Biology and therapy of inherited retinal degenerative disease: insights from mouse models

    PubMed Central

    Veleri, Shobi; Lazar, Csilla H.; Chang, Bo; Sieving, Paul A.; Banin, Eyal; Swaroop, Anand

    2015-01-01

    Retinal neurodegeneration associated with the dysfunction or death of photoreceptors is a major cause of incurable vision loss. Tremendous progress has been made over the last two decades in discovering genes and genetic defects that lead to retinal diseases. The primary focus has now shifted to uncovering disease mechanisms and designing treatment strategies, especially inspired by the successful application of gene therapy in some forms of congenital blindness in humans. Both spontaneous and laboratory-generated mouse mutants have been valuable for providing fundamental insights into normal retinal development and for deciphering disease pathology. Here, we provide a review of mouse models of human retinal degeneration, with a primary focus on diseases affecting photoreceptor function. We also describe models associated with retinal pigment epithelium dysfunction or synaptic abnormalities. Furthermore, we highlight the crucial role of mouse models in elucidating retinal and photoreceptor biology in health and disease, and in the assessment of novel therapeutic modalities, including gene- and stem-cell-based therapies, for retinal degenerative diseases. PMID:25650393

  13. Transcorneal Electrical Stimulation Therapy for Retinal Disease

    ClinicalTrials.gov

    2012-05-03

    Retinitis Pigmentosa; Macula Off; Primary Open Angle Glaucoma; Hereditary Macular Degeneration; Treated Retina Detachment; Retinal Artery Occlusion; Retinal Vein Occlusion; Non-Arthritic-Anterior-Ischemic Optic-Neuropathy; Hereditary Autosomal Dominant Optic Atrophy; Dry Age Related Macular Degeneration; Ischemic Macula Edema

  14. Proof of concept for AAV2/5-mediated gene therapy in iPSC-derived retinal pigment epithelium of a choroideremia patient

    PubMed Central

    Cereso, Nicolas; Pequignot, Marie O; Robert, Lorenne; Becker, Fabienne; De Luca, Valerie; Nabholz, Nicolas; Rigau, Valerie; De Vos, John; Hamel, Christian P; Kalatzis, Vasiliki

    2014-01-01

    Inherited retinal dystrophies (IRDs) comprise a large group of genetically and clinically heterogeneous diseases that lead to progressive vision loss, for which a paucity of disease-mimicking animal models renders preclinical studies difficult. We sought to develop pertinent human cellular IRD models, beginning with choroideremia, caused by mutations in the CHM gene encoding Rab escort protein 1 (REP1). We reprogrammed REP1-deficient fibroblasts from a CHM-/y patient into induced pluripotent stem cells (iPSCs), which we differentiated into retinal pigment epithelium (RPE). This iPSC-derived RPE is a polarized monolayer with a classic morphology, expresses characteristic markers, is functional for fluid transport and phagocytosis, and mimics the biochemical phenotype of patients. We assayed a panel of adeno-associated virus (AAV) vector serotypes and showed that AAV2/5 is the most efficient at transducing the iPSC-derived RPE and that CHM gene transfer normalizes the biochemical phenotype. The high, and unmatched, in vitro transduction efficiency is likely aided by phagocytosis and mimics the scenario that an AAV vector encounters in vivo in the subretinal space. We demonstrate the superiority of AAV2/5 in the human RPE and address the potential of patient iPSC–derived RPE to provide a proof-of-concept model for gene replacement in the absence of an appropriate animal model. PMID:26015956

  15. Adeno-associated virus mediated SOD gene therapy protects the retinal ganglion cells from chronic intraocular pressure elevation induced injury via attenuating oxidative stress and improving mitochondrial dysfunction in a rat model

    PubMed Central

    Jiang, Wenmin; Tang, Luosheng; Zeng, Jun; Chen, Baihua

    2016-01-01

    Purpose: This study aimed to determine whether chronic intraocular pressure (IOP) elevation induces retinal oxidative stress and alters mitochondrial morphology and function of retinal ganglion cells (RGC) and to explore the effects of AAV-SOD2 gene therapy on the RGC survival and mitochondrial dysfunction. Methods: Chronic experimental glaucoma was induced unilaterally in adult male Sprague-Dawley rats by laser burns at trabecular meshwork and episcleral veins 2 times with an interval of one week. One eye of each rat was intravitreally pretreated with recombinant adeno-associated virus expressing SOD2 (AAV-SOD2) or recombinant AAV expressing GFP (AAV-GFP) 21 days before glaucoma induction. RGCs counting, morphometric analysis of retina and optic nerve, and detection of activities of retinal SOD2 and catalase, MDA, mitochondrial morphology, mitochondrial dynamin protein OPA1 and DRP-1 expressions were conducted at 4, 8, 12 and 24 weeks. Results: Severe RGC loss, degeneration of optic nerve, reduced thickness of RGC layer and nerve fiber layer, significant decrease in total SOD and catalase activities, mitochondrial dysfunction and increased MDA were observed at 4, 8, 12 and 24 weeks after glaucoma. Pretreatment with AAV-SOD2 significantly reduced MDA and attenuated the damage to RGCs through a mitochondria-related pathway. Conclusion: AAV mediated pre-treatment with SOD2 is able to attenuate oxidative stress and improve mitochondrial dysfunction of RGC and optic nerve secondary to glaucoma. Thus, SOD2 may be used to prevent the retinal RGCs from glaucoma, which provides a promising strategy for glaucoma therapy. PMID:27158370

  16. Oligochitosan polyplexes as carriers for retinal gene delivery.

    PubMed

    Puras, G; Zarate, J; Díaz-Tahoces, A; Avilés-Trigueros, Marcelino; Fernández, E; Pedraz, J L

    2013-01-23

    Non-viral gene therapy represents a promising approach for the treatment of retinal diseases. However, the lack of an efficient carrier hampers the implementation of this therapy. In this study, we evaluated low molecular weight ultrapure oligochitosans for the delivery of the pCMS-EGFP plasmid into the rat retina cells after subretinal and intravitreal administrations. Polyplexes were technologically characterized. Resulting polyplexes based on ultrapure oligochitosans were slightly spherical, protected the plasmid against enzymatic digestion, and their charge and size values ranged from 8 to 14 millivolts and from 150 to 69 nm respectively depending on the N/P ratio. In HEK-293 cultured cells, transfection efficiency significantly increased from 12% to 30% when pH decreased from 7.4 to 7.1 (data normalized to Lipofectamine™ 2000). However, no significant transfection was detected in ARPE-19 cultured cells. Subretinal administrations transfected mainly the pigmented cells of the retinal pigment epithelium and the light sensitive photoreceptor cells, whereas intravitreal injections transfected cells in the ganglion cell layer, blood vessels in the inner layers of the retina and photoreceptors. These results support the potential use of oligochitosans for delivering genetic material into retinal cells in vivo. PMID:23201002

  17. Identification of Genes and Pathways Involved in Retinal Neovascularization by Microarray Analysis of Two Animal Models of Retinal Angiogenesis

    PubMed Central

    Xu, Lili; Penn, John S.; Boone, Braden; Dexheimer, Phillip J.

    2010-01-01

    Purpose. Comparative retinal gene expression analysis in two rodent models of oxygen-induced retinopathy (OIR) was performed to identify the genes and pathways involved in retinal neovascularization. Methods. Three independent experimental runs were conducted for each species, according to standard protocols for induction of OIR. Total retinal RNA was isolated at two time points, corresponding to the early response to relative hypoxia (P13 in mouse, P15 in rat) and to the later phase of maximum retinal neovascularization (P18 in mouse, P20 in rat) and was used to prepare labeled probes for hybridization. Gene expression was compared between normal and experimental conditions for each species at each time point. Probesets with a false-discovery rate of ≤0.05 were considered significantly different and were classified as cellular functions or biological pathways. Changes in expression of selected genes were confirmed by quantitative rtPCR. Results. At the early time point, there were changes in 43 genes in each species, with two in common. Increased expression of members of the VEGF and ephrin receptor signaling pathways were identified in both models. At the later time point, there were changes in 26 genes in the rat and in 1622 in the mouse, with 13 in common. Four pathways were identified in both models. Conclusions. Genes and pathways known to be involved in angiogenesis, as well as other biologically plausible genes and pathways, were identified. This work serves as a comprehensive resource for the study of retinal neovascularization and identification of potential rational targets for antiangiogenic therapy. PMID:19834031

  18. Effects of Subretinal Gene Transfer at Different Time Points in a Mouse Model of Retinal Degeneration

    PubMed Central

    Dai, Xufeng; Zhang, Hua; Han, Juanjuan; He, Ying; Zhang, Yangyang; Qi, Yan; Pang, Ji-jing

    2016-01-01

    Lysophosphatidylcholine acyltransferase 1 (LPCAT1) is necessary for photoreceptors to generate an important lipid component of their membranes. The absence of LPCAT1 results in early and rapid rod and cone degeneration. Retinal degeneration 11 (rd11) mice carry a mutation in the Lpcat1 gene, and are an excellent model of early-onset rapid retinal degeneration (RD). To date, no reports have documented gene therapy administration in the rd11 mouse model at different ages. In this study, the AAV8 (Y733F)-smCBA-Lpcat1 vector was subretinally injected at postnatal day (P) 10, 14, 18, or 22. Four months after injection, immunohistochemistry and analysis of retinal morphology showed that treatment at P10 rescued about 82% of the wild-type retinal thickness. However, the diffusion of the vector and the resulting rescue were limited to an area around the injection site that was only 31% of the total retinal area. Injection at P14 resulted in vector diffusion that covered approximately 84% of the retina, and we found that gene therapy was more effective against RD when exposure to light was limited before and after treatment. We observed long-term preservation of electroretinogram (ERG) responses, and preservation of retinal structure, indicating that early treatment followed by limited light exposure can improve gene therapy effectiveness for the eyes of rd11 mice. Importantly, delayed treatment still partially preserved M-cones, but not S-cones, and M-cones in the rd11 retina appeared to have a longer window of opportunity for effective preservation with gene therapy. These results provide important information regarding the effects of subretinal gene therapy in the mouse model of LPCAT1-deficiency. PMID:27228218

  19. The gene therapy revolution in ophthalmology

    PubMed Central

    Al-Saikhan, Fahad I.

    2013-01-01

    The advances in gene therapy hold significant promise for the treatment of ophthalmic conditions. Several studies using animal models have been published. Animal models on retinitis pigmentosa, Leber’s Congenital Amaurosis (LCA), and Stargardt disease have involved the use of adeno-associated virus (AAV) to deliver functional genes into mice and canines. Mice models have been used to show that a mutation in cGMP phosphodiesterase that results in retinitis pigmentosa can be corrected using rAAV vectors. Additionally, rAAV vectors have been successfully used to deliver ribozyme into mice with a subsequent improvement in autosomal dominant retinitis pigmentosa. By using dog models, researchers have made progress in studying X-linked retinitis pigmentosa which results from a RPGR gene mutation. Mouse and canine models have also been used in the study of LCA. The widely studied form of LCA is LCA2, resulting from a mutation in the gene RPE65. Mice and canines that were injected with normal copies of RPE65 gene showed signs such as improved retinal pigment epithelium transduction, visual acuity, and functional recovery. Studies on Stargardt disease have shown that mutations in the ABCA4 gene can be corrected with AAV vectors, or nanoparticles. Gene therapy for the treatment of red–green color blindness was successful in squirrel monkeys. Plans are at an advanced stage to begin clinical trials. Researchers have also proved that CD59 can be used with AMD. Gene therapy is also able to treat primary open angle glaucoma (POAG) in animal models, and studies show it is economically viable. PMID:24227970

  20. Neuroprotective therapy for argon-laser-induced retinal injury

    NASA Astrophysics Data System (ADS)

    Belkin, Michael; Rosner, Mordechai; Solberg, Yoram; Turetz, Yosef

    1999-06-01

    Laser photocoagulation treatment of the central retina is often complicated by an immediate side effect of visual impairment, caused by the unavoidable laser-induced destruction of the normal tissue lying adjacent to the lesion and not affected directly by the laser beam. Furthermore, accidental laser injuries are at present untreatable. A neuroprotective therapy for salvaging the normal tissue might enhance the benefit obtained from treatment and allow safe perifoveal photocoagulation. We have developed a rat model for studying the efficacy of putative neuroprotective compounds in ameliorating laser-induced retinal damage. Four compounds were evaluated: the corticosteroid methylprednisolone, the glutamate-receptor blocker MK-801, the anti-oxidant enzyme superoxide dismutase, and the calcim-overload antagonist flunarizine. The study was carried out in two steps: in the first, the histopathological development of retinal laser injuries was studied. Argon laser lesions were inflicted in the retinas of 18 pigmented rats. The animals were sacrificed after 3, 20 or 60 days and their retinal lesions were evaluated under the light microscope. The laser injury mainly involved the outer layers of the retina, where it destroyed significant numbers of photoreceptor cells. Over time, evidence of two major histopathological processes was observed: traction of adjacent nomral retinal cells into the central area of the lesion forming an internal retinal bulging, and a retinal pigmented epithelial proliferative reaction associated with subretinal neovascularization and invations of the retinal lesion site by phagocytes. The neuroprotective effects of each of the four compounds were verified in a second step of the study. For each drug tested, 12 rats were irradiated wtih argon laser inflictions: six of them received the tested agent while the other six were treated with the corresponding vehicle. Twenty days after laser expsoure, the rats were sacrificed and their lesions were

  1. Selective retinal therapy with a continuous line scanning laser

    NASA Astrophysics Data System (ADS)

    Paulus, Yannis M.; Jain, ATul; Gariano, Ray F.; Nomoto, Hiroyuki; Schuele, Georg; Sramek, Christopher; Charalel, Resmi; Palanker, Daniel

    2010-02-01

    This study evaluates the effects of exposure duration, beam diameter, and power on the safety, selectivity, and healing of retinal lesions created using a continuous line scanning laser. A 532 nm laser (PASCALTM) with retinal beam diameters of 40 and 66 μm was applied to 60 eyes of 30 Dutch-Belted rabbits. Retinal exposure duration varied from 15 to 60 μs. Lesions were acutely assessed by ophthalmoscopy and fluorescein angiography (FA). RPE flatmounts were evaluated with live-dead fluorescent assay (LD). Histological analysis was performed at 1 hour, 1 and 3 days, 1 and 2 weeks, and 1 and 2 months following laser treatment. Ophthalmoscopic visibility (OV) of the lesions corresponded to photoreceptor damage on histological analysis at 1 hour. In subvisible lesions, FA and LD yielded similar thresholds of RPE damage. The ratios of the threshold of rupture and of OV to FA visibility (measures of safety and selectivity) increased with decreasing duration and beam diameter. Above the threshold of OV, histology showed focal RPE damage and photoreceptor loss at one day without inner retinal effects. By one week, continuity of photoreceptor and RPE layers was restored. By 1 month, photoreceptors appeared normal while hypertrophy and hyperpigmentation of the RPE persisted. Retinal therapy with a fast scanning continuous laser achieves selective targeting of the RPE and, at higher power, of the photoreceptors. The damage zone in the photoreceptor layer is quickly filled-in, likely due to photoreceptor migration from adjacent zones. Continuous scanning laser can treat large retinal areas within standard eye fixation time.

  2. History of gene therapy.

    PubMed

    Wirth, Thomas; Parker, Nigel; Ylä-Herttuala, Seppo

    2013-08-10

    Two decades after the initial gene therapy trials and more than 1700 approved clinical trials worldwide we not only have gained much new information and knowledge regarding gene therapy in general, but also learned to understand the concern that has persisted in society. Despite the setbacks gene therapy has faced, success stories have increasingly emerged. Examples for these are the positive recommendation for a gene therapy product (Glybera) by the EMA for approval in the European Union and the positive trials for the treatment of ADA deficiency, SCID-X1 and adrenoleukodystrophy. Nevertheless, our knowledge continues to grow and during the course of time more safety data has become available that helps us to develop better gene therapy approaches. Also, with the increased understanding of molecular medicine, we have been able to develop more specific and efficient gene transfer vectors which are now producing clinical results. In this review, we will take a historical view and highlight some of the milestones that had an important impact on the development of gene therapy. We will also discuss briefly the safety and ethical aspects of gene therapy and address some concerns that have been connected with gene therapy as an important therapeutic modality. PMID:23618815

  3. Regeneration of the retina: toward stem cell therapy for degenerative retinal diseases.

    PubMed

    Jeon, Sohee; Oh, Il-Hoan

    2015-04-01

    Degenerative retinal diseases affect millions of people worldwide, which can lead to the loss of vision. However, therapeutic approaches that can reverse this process are limited. Recent efforts have allowed the possibility of the stem cell-based regeneration of retinal cells and repair of injured retinal tissues. Although the direct differentiation of pluripotent stem cells into terminally differentiated photoreceptor cells comprises one approach, a series of studies revealed the intrinsic regenerative potential of the retina using endogenous retinal stem cells. Muller glial cells, ciliary pigment epithelial cells, and retinal pigment epithelial cells are candidates for such retinal stem cells that can differentiate into multiple types of retinal cells and be integrated into injured or developing retina. In this review, we explore our current understanding of the cellular identity of these candidate retinal stem cells and their therapeutic potential for cell therapy against degenerative retinal diseases. PMID:25560700

  4. Signaling Networks of Retinal Ganglion Cell Formation and the Potential Application of Stem Cell-Based Therapy in Retinal Degenerative Diseases.

    PubMed

    Wu, Nan; Wang, Yi; Yang, Lanbo; Cho, Kin-Sang

    2016-08-01

    Retinal degenerative diseases such as age-related macular degeneration, retinitis pigmentosa, and glaucoma result in permanent loss of retinal neurons and vision. Stem cell therapy could be a novel treatment strategy to restore visual function. In an ideal situation, a homogenous population of stem cell-derived retinal neurons with high purity is used for replacement therapy. Thus, it is crucial to elucidate the molecular mechanisms that regulate the development of retinal progenitor cells and subsequent generation of specific retinal neurons. Here, recent findings concerning the intrinsic and extrinsic factors that regulate retinal progenitor cell maintenance and differentiation are summarized, especially transcriptional factors and extrinsic signals. Understanding these mechanisms is indispensable because they have potential clinical applications, chiefly the generation of specific retinal cells such as retinal ganglion cells to treat glaucoma and other optic neuropathy diseases. PMID:27466076

  5. 76 FR 22405 - Cellular, Tissue and Gene Therapies Advisory Committee; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-21

    ... HUMAN SERVICES Food and Drug Administration Cellular, Tissue and Gene Therapies Advisory Committee... be open to the public. Name of Committee: Cellular, Tissue and Gene Therapies Advisory Committee... gene therapy products for the treatment of retinal disorders. Topics to be considered include...

  6. Clinical characteristics and current therapies for inherited retinal degenerations.

    PubMed

    Sahel, José-Alain; Marazova, Katia; Audo, Isabelle

    2015-02-01

    Inherited retinal degenerations (IRDs) encompass a large group of clinically and genetically heterogeneous diseases that affect approximately 1 in 3000 people (>2 million people worldwide) (Bessant DA, Ali RR, Bhattacharya SS. 2001. Molecular genetics and prospects for therapy of the inherited retinal dystrophies. Curr Opin Genet Dev 11: 307-316.). IRDs may be inherited as Mendelian traits or through mitochondrial DNA, and may affect the entire retina (e.g., rod-cone dystrophy, also known as retinitis pigmentosa, cone dystrophy, cone-rod dystrophy, choroideremia, Usher syndrome, and Bardet-Bidel syndrome) or be restricted to the macula (e.g., Stargardt disease, Best disease, and Sorsby fundus dystrophy), ultimately leading to blindness. IRDs are a major cause of severe vision loss, with profound impact on patients and society. Although IRDs remain untreatable today, significant progress toward therapeutic strategies for IRDs has marked the past two decades. This progress has been based on better understanding of the pathophysiological pathways of these diseases and on technological advances. PMID:25324231

  7. Vector platforms for gene therapy of inherited retinopathies

    PubMed Central

    Trapani, Ivana; Puppo, Agostina; Auricchio, Alberto

    2014-01-01

    Inherited retinopathies (IR) are common untreatable blinding conditions. Most of them are inherited as monogenic disorders, due to mutations in genes expressed in retinal photoreceptors (PR) and in retinal pigment epithelium (RPE). The retina’s compatibility with gene transfer has made transduction of different retinal cell layers in small and large animal models via viral and non-viral vectors possible. The ongoing identification of novel viruses as well as modifications of existing ones based either on rational design or directed evolution have generated vector variants with improved transduction properties. Dozens of promising proofs of concept have been obtained in IR animal models with both viral and non-viral vectors, and some of them have been relayed to clinical trials. To date, recombinant vectors based on the adeno-associated virus (AAV) represent the most promising tool for retinal gene therapy, given their ability to efficiently deliver therapeutic genes to both PR and RPE and their excellent safety and efficacy profiles in humans. However, AAVs’ limited cargo capacity has prevented application of the viral vector to treatments requiring transfer of genes with a coding sequence larger than 5 kb. Vectors with larger capacity, i.e. nanoparticles, adenoviral and lentiviral vectors are being exploited for gene transfer to the retina in animal models and, more recently, in humans. This review focuses on the available platforms for retinal gene therapy to fight inherited blindness, highlights their main strengths and examines the efforts to overcome some of their limitations. PMID:25124745

  8. Prioritization of Retinal Disease Genes: An Integrative Approach

    PubMed Central

    Wagner, Alex H.; Taylor, Kyle R.; DeLuca, Adam P.; Casavant, Thomas L.; Mullins, Robert F.; Stone, Edwin M.; Scheetz, Todd E.; Braun, Terry A.

    2015-01-01

    The discovery of novel disease-associated variations in genes is often a daunting task in highly heterogeneous disease classes. We seek a generalizable algorithm that integrates multiple publicly available genomic data sources in a machine-learning model for the prioritization of candidates identified in patients with retinal disease. To approach this problem, we generate a set of feature vectors from publicly available microarray, RNA-seq, and ChIP-seq datasets of biological relevance to retinal disease, to observe patterns in gene expression specificity among tissues of the body and the eye, in addition to photoreceptor-specific signals by the CRX transcription factor. Using these features, we describe a novel algorithm, positive and unlabeled learning for prioritization (PULP). This article compares several popular supervised learning techniques as the regression function for PULP. The results demonstrate a highly significant enrichment for previously characterized disease genes using a logistic regression method. Finally, a comparison of PULP with the popular gene prioritization tool ENDEAVOUR shows superior prioritization of retinal disease genes from previous studies. PMID:23508994

  9. Hydroxyl PAMAM dendrimer-based gene vectors for transgene delivery to human retinal pigment epithelial cells

    NASA Astrophysics Data System (ADS)

    Mastorakos, Panagiotis; Kambhampati, Siva P.; Mishra, Manoj K.; Wu, Tony; Song, Eric; Hanes, Justin; Kannan, Rangaramanujam M.

    2015-02-01

    Ocular gene therapy holds promise for the treatment of numerous blinding disorders. Despite the significant progress in the field of viral and non-viral gene delivery to the eye, significant obstacles remain in the way of achieving high-level transgene expression without adverse effects. The retinal pigment epithelium (RPE) is involved in the pathogenesis of retinal diseases and is a key target for a number of gene-based therapeutics. In this study, we addressed the inherent drawbacks of non-viral gene vectors and combined different approaches to design an efficient and safe dendrimer-based gene-delivery platform for delivery to human RPE cells. We used hydroxyl-terminated polyamidoamine (PAMAM) dendrimers functionalized with various amounts of amine groups to achieve effective plasmid compaction. We further used triamcinolone acetonide (TA) as a nuclear localization enhancer for the dendrimer-gene complex and achieved significant improvement in cell uptake and transfection of hard-to-transfect human RPE cells. To improve colloidal stability, we further shielded the gene vector surface through incorporation of PEGylated dendrimer along with dendrimer-TA for DNA complexation. The resultant complexes showed improved stability while minimally affecting transgene delivery, thus improving the translational relevance of this platform.Ocular gene therapy holds promise for the treatment of numerous blinding disorders. Despite the significant progress in the field of viral and non-viral gene delivery to the eye, significant obstacles remain in the way of achieving high-level transgene expression without adverse effects. The retinal pigment epithelium (RPE) is involved in the pathogenesis of retinal diseases and is a key target for a number of gene-based therapeutics. In this study, we addressed the inherent drawbacks of non-viral gene vectors and combined different approaches to design an efficient and safe dendrimer-based gene-delivery platform for delivery to human RPE

  10. Vaginal gene therapy.

    PubMed

    Rodríguez-Gascón, Alicia; Del Pozo-Rodríguez, Ana; Isla, Arantxazu; Solinís, María Angeles

    2015-09-15

    In the last years, vaginal gene therapy has gained increasing attention mainly for the treatment and control of sexually transmitted infections. DNA delivery has been also suggested to improve reproductive outcomes for women with deficiencies in the female reproductive tract. Although no product has reached clinical phase, preclinical investigations reveal the potential of the vaginal tract as an effective administration route for gene delivery. This review focuses on the main advantages and challenges of vaginal gene therapy, and on the most used nucleic acid delivery systems, including viral and non-viral vectors. Additionally, the advances in the application of vaginal gene therapy for the treatment and/or prevention of infectious diseases such as the human immunodeficiency virus (HIV), the human papillomavirus (HPV) or the herpes simplex virus (HSV) are presented. PMID:26189799

  11. Gene therapy in epilepsy

    PubMed Central

    Riban, Véronique; Fitzsimons, Helen L.; During, Matthew J.

    2009-01-01

    SUMMARY Results from animal models suggest gene therapy is a promising new approach for the treatment of epilepsy. Several candidate genes such as neuropeptide Y and galanin have been demonstrated in preclinical studies to have a positive effect on seizure activity. For a successful gene therapy-based treatment, efficient delivery of a transgene to target neurons is also essential. To this end, advances have been made in the areas of cell transplantation and in the development of recombinant viral vectors for gene delivery. Recombinant adeno-associated viral (rAAV) vectors in particular show promise for gene therapy of neurological disorders due to their neuronal tropism, lack of toxicity, and stable persistence in neurons, which results in robust, long-term expression of the transgene. rAAV vectors have been recently used in phase I clinical trials of Parkinson’s disease with an excellent safety profile. Prior to commencement of phase I trials for gene therapy of epilepsy, further preclinical studies are ongoing including evaluation of the therapeutic benefit in chronicmodels of epileptogenesis, as well as assessment of safety intoxicological studies. PMID:18717707

  12. Impact of injection therapy on retinal patients with diabetic macular edema or retinal vein occlusion

    PubMed Central

    Sivaprasad, Sobha; Oyetunde, Sesan

    2016-01-01

    Purpose An important factor in the choice of therapy is the impact it has on the patient’s quality of life. This survey aimed to understand treatment burden, treatment-related anxiety and worry, and practical issues such as appointment attendance and work absence in patients receiving injection therapy for diabetic macular edema (DME) or retinal vein occlusion (RVO). Patients and methods A European sample of 131 retinal patients completed a detailed questionnaire to elucidate the impact of injection therapy on individuals with DME or RVO. Results RVO and DME greatly impact a patient’s quality of life. An intensive injection regimen and the requirements for multiple hospital visits place a large practical burden on the patient. Each intravitreal injection appointment (including travel time) was reported to take an average of 4.5 hours, with a total appointment burden over 6 months of 13.5 hours and 20 hours for RVO and DME patients, respectively. This creates a significant burden on patient time and may make appointment attendance difficult. Indeed, 53% of working patients needed to take at least 1 day off work per appointment and 71% of patients required a carer’s assistance at the time of the injection appointment, ~6.3 hours per injection. In addition to practical issues, three-quarters of patients reported experiencing anxiety about their most recent injection treatment, with 54% of patients reporting that they were anxious for at least 2 days prior to the injection. Patients’ most desired improvement to their treatment regimen was to have fewer injections and to require fewer appointments, to achieve the same visual results. Conclusion Patients’ quality of life is clearly very affected by having to manage an intensive intravitreal injection regimen, with a considerable treatment burden having a large negative effect. Reducing the appointment burden to achieve the same visual outcomes and the provision of additional support for patients to attend

  13. Distilling a Visual Network of Retinitis Pigmentosa Gene-Protein Interactions to Uncover New Disease Candidates

    PubMed Central

    Boloc, Daniel; Castillo-Lara, Sergio; Marfany, Gemma; Gonzàlez-Duarte, Roser; Abril, Josep F.

    2015-01-01

    Background Retinitis pigmentosa (RP) is a highly heterogeneous genetic visual disorder with more than 70 known causative genes, some of them shared with other non-syndromic retinal dystrophies (e.g. Leber congenital amaurosis, LCA). The identification of RP genes has increased steadily during the last decade, and the 30% of the cases that still remain unassigned will soon decrease after the advent of exome/genome sequencing. A considerable amount of genetic and functional data on single RD genes and mutations has been gathered, but a comprehensive view of the RP genes and their interacting partners is still very fragmentary. This is the main gap that needs to be filled in order to understand how mutations relate to progressive blinding disorders and devise effective therapies. Methodology We have built an RP-specific network (RPGeNet) by merging data from different sources: high-throughput data from BioGRID and STRING databases, manually curated data for interactions retrieved from iHOP, as well as interactions filtered out by syntactical parsing from up-to-date abstracts and full-text papers related to the RP research field. The paths emerging when known RP genes were used as baits over the whole interactome have been analysed, and the minimal number of connections among the RP genes and their close neighbors were distilled in order to simplify the search space. Conclusions In contrast to the analysis of single isolated genes, finding the networks linking disease genes renders powerful etiopathological insights. We here provide an interactive interface, RPGeNet, for the molecular biologist to explore the network centered on the non-syndromic and syndromic RP and LCA causative genes. By integrating tissue-specific expression levels and phenotypic data on top of that network, a more comprehensive biological view will highlight key molecular players of retinal degeneration and unveil new RP disease candidates. PMID:26267445

  14. Perspectives on best practices for gene therapy programs.

    PubMed

    Cheever, Thomas R; Berkley, Dale; Braun, Serge; Brown, Robert H; Byrne, Barry J; Chamberlain, Jeffrey S; Cwik, Valerie; Duan, Dongsheng; Federoff, Howard J; High, Katherine A; Kaspar, Brian K; Klinger, Katherine W; Larkindale, Jane; Lincecum, John; Mavilio, Fulvio; McDonald, Cheryl L; McLaughlin, James; Weiss McLeod, Bonnie; Mendell, Jerry R; Nuckolls, Glen; Stedman, Hansell H; Tagle, Danilo A; Vandenberghe, Luk H; Wang, Hao; Wernett, Pamela J; Wilson, James M; Porter, John D; Gubitz, Amelie K

    2015-03-01

    With recent successes in gene therapy trials for hemophilia and retinal diseases, the promise and prospects for gene therapy are once again garnering significant attention. To build on this momentum, the National Institute of Neurological Disorders and Stroke and the Muscular Dystrophy Association jointly hosted a workshop in April 2014 on "Best Practices for Gene Therapy Programs," with a focus on neuromuscular disorders. Workshop participants included researchers from academia and industry as well as representatives from the regulatory, legal, and patient advocacy sectors to cover the gamut from preclinical optimization to intellectual property concerns and regulatory approval. The workshop focused on three key issues in the field: (1) establishing adequate scientific premise for clinical trials in gene therapy, (2) addressing regulatory process issues, and (3) intellectual property and commercialization issues as they relate to gene therapy. The outcomes from the discussions at this workshop are intended to provide guidance for researchers and funders in the gene therapy field. PMID:25654329

  15. Hydroxyl PAMAM dendrimer-based gene vectors for transgene delivery to human retinal pigment epithelial cells†

    PubMed Central

    Mastorakos, Panagiotis; Kambhampati, Siva P.; Mishra, Manoj K.; Wu, Tony; Song, Eric; Hanes, Justin

    2016-01-01

    Ocular gene therapy holds promise for the treatment of numerous blinding disorders. Despite the significant progress in the field of viral and non-viral gene delivery to the eye, significant obstacles remain in the way of achieving high-level transgene expression without adverse effects. The retinal pigment epithelium (RPE) is involved in the pathogenesis of retinal diseases and is a key target for a number of gene-based therapeutics. In this study, we addressed the inherent drawbacks of non-viral gene vectors and combined different approaches to design an efficient and safe dendrimer-based gene-delivery platform for delivery to human RPE cells. We used hydroxyl-terminated polyamidoamine (PAMAM) dendrimers functionalized with various amounts of amine groups to achieve effective plasmid compaction. We further used triamcinolone acetonide (TA) as a nuclear localization enhancer for the dendrimer-gene complex and achieved significant improvement in cell uptake and transfection of hard-to-transfect human RPE cells. To improve colloidal stability, we further shielded the gene vector surface through incorporation of PEGylated dendrimer along with dendrimer-TA for DNA complexation. The resultant complexes showed improved stability while minimally affecting transgene delivery, thus improving the translational relevance of this platform. PMID:25213606

  16. Central Retinal Artery Occlusion: A Literature Review and the Rationale for Hyperbaric Oxygen Therapy.

    PubMed

    Olson, Evan A; Lentz, Kathy

    2016-01-01

    Central retinal artery occlusion is visually devastating and has no proven treatments. The therapeutic interval between symptom onset and potentially sight-saving intervention is narrow. Traditional conservative approaches include digital massage, administration of systemic vasodilators and diuretics, and lowering of intraocular pressure. Systemic and targeted fibrinolytic therapy is under investigation but is associated with significant adverse reactions. We report a case in which hyperbaric oxygen therapy restored retinal perfusion, and the patient's vision was improved. PMID:27039492

  17. Progressive Outer Retinal Necrosis and Immunosuppressive Therapy in Myasthenia Gravis

    PubMed Central

    Coisy, Solène; Ebran, Jean-Marc; Milea, Dan

    2014-01-01

    Introduction Progressive outer retinal necrosis (PORN) is a rare but devastating infectious retinitis associated with varicella zoster virus (VZV) and responsible for severe visual loss. Case Report A 59-year-old man treated for generalized myasthenia with oral azathioprine and prednisone presented with severe unilateral necrotizing retinitis. Polymerase chain reaction of the aqueous and vitreous humors was diagnostic for VZV PORN. Conclusion VZV PORN is a severe potential ocular complication of immunosuppression, prompting urgent diagnosis and appropriate treatment. PMID:24926266

  18. Development of gene and stem cell therapy for ocular neurodegeneration

    PubMed Central

    Zhang, Jing-Xue; Wang, Ning-Li; Lu, Qing-Jun

    2015-01-01

    Retinal degenerative diseases pose a serious threat to eye health, but there is currently no effective treatment available. Recent years have witnessed rapid development of several cutting-edge technologies, such as gene therapy, stem cell therapy, and tissue engineering. Due to the special features of ocular structure, some of these technologies have been translated into ophthalmological clinic practice with fruitful achievements, setting a good example for other fields. This paper reviews the development of the gene and stem cell therapies in ophthalmology. PMID:26086019

  19. Gene therapy in pancreatic cancer

    PubMed Central

    Liu, Si-Xue; Xia, Zhong-Sheng; Zhong, Ying-Qiang

    2014-01-01

    Pancreatic cancer (PC) is a highly lethal disease and notoriously difficult to treat. Only a small proportion of PC patients are eligible for surgical resection, whilst conventional chemoradiotherapy only has a modest effect with substantial toxicity. Gene therapy has become a new widely investigated therapeutic approach for PC. This article reviews the basic rationale, gene delivery methods, therapeutic targets and developments of laboratory research and clinical trials in gene therapy of PC by searching the literature published in English using the PubMed database and analyzing clinical trials registered on the Gene Therapy Clinical Trials Worldwide website (http://www. wiley.co.uk/genmed/ clinical). Viral vectors are main gene delivery tools in gene therapy of cancer, and especially, oncolytic virus shows brighter prospect due to its tumor-targeting property. Efficient therapeutic targets for gene therapy include tumor suppressor gene p53, mutant oncogene K-ras, anti-angiogenesis gene VEGFR, suicide gene HSK-TK, cytosine deaminase and cytochrome p450, multiple cytokine genes and so on. Combining different targets or combination strategies with traditional chemoradiotherapy may be a more effective approach to improve the efficacy of cancer gene therapy. Cancer gene therapy is not yet applied in clinical practice, but basic and clinical studies have demonstrated its safety and clinical benefits. Gene therapy will be a new and promising field for the treatment of PC. PMID:25309069

  20. nanosheets for gene therapy

    NASA Astrophysics Data System (ADS)

    Kou, Zhongyang; Wang, Xin; Yuan, Renshun; Chen, Huabin; Zhi, Qiaoming; Gao, Ling; Wang, Bin; Guo, Zhaoji; Xue, Xiaofeng; Cao, Wei; Guo, Liang

    2014-10-01

    A new class of two-dimensional (2D) nanomaterial, transition metal dichalcogenides (TMDCs) such as MoS2, MoSe2, WS2, and WSe2 which have fantastic physical and chemical properties, has drawn tremendous attention in different fields recently. Herein, we for the first time take advantage of the great potential of MoS2 with well-engineered surface as a novel type of 2D nanocarriers for gene delivery and therapy of cancer. In our system, positively charged MoS2-PEG-PEI is synthesized with lipoic acid-modified polyethylene glycol (LA-PEG) and branched polyethylenimine (PEI). The amino end of positively charged nanomaterials can bind to the negatively charged small interfering RNA (siRNA). After detection of physical and chemical characteristics of the nanomaterial, cell toxicity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Polo-like kinase 1 (PLK1) was investigated as a well-known oncogene, which was a critical regulator of cell cycle transmission at multiple levels. Through knockdown of PLK1 with siRNA carried by novel nanovector, qPCR and Western blot were used to measure the interfering efficiency; apoptosis assay was used to detect the transfection effect of PLK1. All results showed that the novel nanocarrier revealed good biocompatibility, reduced cytotoxicity, as well as high gene-carrying ability without serum interference, thus would have great potential for gene delivery and therapy.

  1. Saporin suicide gene therapy.

    PubMed

    Zarovni, Natasa; Vago, Riccardo; Fabbrini, Maria Serena

    2009-01-01

    New genes useful in suicide gene therapy are those encoding toxins such as plant ribosome-inactivating proteins (RIPs), which can irreversibly block protein synthesis, triggering apoptotic cell death. Plasmids expressing a cytosolic saporin (SAP) gene from common soapwort (Saponaria officinalis) are generated by placing the region encoding the mature plant toxin under the control of strong viral promoters and may be placed under tumor-specific promoters. The ability of the resulting constructs to inhibit protein synthesis is tested in cultured tumor cells co-transfected with a luciferase reporter gene. SAP expression driven by the cytomegalovirus (CMV) promoter (pCI-SAP) demonstrates that only 10 ng ofplasmid DNA per 1.6 x 10(4) B16 melanoma cells drastically reduces luciferase reporter activity to 18% of that in control cells (1). Direct intratumoral injections are performed in an aggressive melanoma model. B16 melanoma-bearing mice injected with pCI-SAP complexed with lipofectamine or N-(2,3-dioleoyloxy-1-propyl) trimethylammonium methyl sulfate (DOTAP) show a noteworthy attenuation in tumor growth, and this effect is significantly augmented by repeated administrations of the DNA complexes. Here, we describe in detail this cost-effective and safe suicide gene approach. PMID:19565907

  2. Promising and delivering gene therapies for vision loss

    PubMed Central

    Carvalho, Livia S.; Vandenberghe, Luk H.

    2014-01-01

    The maturity in our understanding of the genetics and the pathogenesis of disease in degenerative retinal disorders has intersected in past years with a novel treatment paradigm in which a genetic intervention may lead to sustained therapeutic benefit, and in some cases even restoration of vision. Here, we review this prospect of retinal gene therapy, discuss the enabling technologies that have led to first-in-human demonstrations of efficacy and safety, and the road that led to this exciting point in time. PMID:25094052

  3. Cardiac Gene Therapy

    PubMed Central

    Chaanine, Antoine H.; Kalman, Jill; Hajjar, Roger J.

    2010-01-01

    Heart failure is a chronic progressive disorder where frequent and recurrent hospitalizations are associated with high mortality and morbidity. The incidence and the prevalence of this disease will increase with the increase in the number of the aging population of the United States. Understanding the molecular pathology and pathophysiology of this disease will uncover novel targets and therapies that can restore the function or attenuate the damage of malfunctioning cardiomyocytes by gene therapy that becomes an interesting and a promising field for the treatment of heart failure as well as other diseases in the future. Of equal importance is developing vectors and delivery methods that can efficiently transduce the majority of the cardiomyocytes, that can offer a long term expression and that can escape the host immune response. Recombinant adeno-associated virus vectors have the potential to become a promising novel therapeutic vehicles for molecular medicine in the future. PMID:21092890

  4. Retinal vascular regeneration.

    PubMed

    Otani, Atsushi; Friedlander, Martin

    2005-01-01

    We discuss the potential use of stem cells for therapeutic angiogenesis in the treatment of retinal diseases. We demonstrate that the clinical utility of these EPC may be not limited in the treatment of ischemic retinal diseases but may also have application for the treatment of retinal degenerative disorders and for a form of cell-based gene therapy. One of the greatest potential benefits of bone marrow derived EPC therapy is the possible use of autologous grafts. Nonetheless, potential toxicities and unregulated cell growth will need to be carefully evaluated before this approach is brought to the clinics. PMID:15804843

  5. Gene therapy in keratoconus

    PubMed Central

    Farjadnia, Mahgol; Naderan, Mohammad; Mohammadpour, Mehrdad

    2015-01-01

    Keratoconus (KC) is the most common ectasia of the cornea and is a common reason for corneal transplant. Therapeutic strategies that can arrest the progression of this disease and modify the underlying pathogenesis are getting more and more popularity among scientists. Cumulating data represent strong evidence of a genetic role in the pathogenesis of KC. Different loci have been identified, and certain mutations have also been mapped for this disease. Moreover, Biophysical properties of the cornea create an appropriate candidate of this tissue for gene therapy. Immune privilege, transparency and ex vivo stability are among these properties. Recent advantage in vectors, besides the ability to modulate the corneal milieu for accepting the target gene for a longer period and fruitful translation, make a big hope for stupendous results reasonable. PMID:25709266

  6. Human Gene Therapy: Genes without Frontiers?

    ERIC Educational Resources Information Center

    Simon, Eric J.

    2002-01-01

    Describes the latest advancements and setbacks in human gene therapy to provide reference material for biology teachers to use in their science classes. Focuses on basic concepts such as recombinant DNA technology, and provides examples of human gene therapy such as severe combined immunodeficiency syndrome, familial hypercholesterolemia, and…

  7. Features specific to retinal pigment epithelium cells derived from three-dimensional human embryonic stem cell cultures — a new donor for cell therapy

    PubMed Central

    Li, Zhengya; Li, Qiyou; Xu, Haiwei; Yin, Zheng Qin

    2016-01-01

    Retinal pigment epithelium (RPE) transplantation is a particularly promising treatment of retinal degenerative diseases affecting RPE-photoreceptor complex. Embryonic stem cells (ESCs) provide an abundant donor source for RPE transplantation. Herein, we studied the time-course characteristics of RPE cells derived from three-dimensional human ESCs cultures (3D-RPE). We showed that 3D-RPE cells possessed morphology, ultrastructure, gene expression profile, and functions of authentic RPE. As differentiation proceeded, 3D-RPE cells could mature gradually with decreasing proliferation but increasing functions. Besides, 3D-RPE cells could form polarized monolayer with functional tight junction and gap junction. When grafted into the subretinal space of Royal College of Surgeons rats, 3D-RPE cells were safe and efficient to rescue retinal degeneration. This study showed that 3D-RPE cells were a new donor for cell therapy of retinal degenerative diseases. PMID:27009841

  8. EFFICIENT GENE TRANSFER TO RETINAL PIGMENT EPITHELIUM CELLS WITH LONG-TERM EXPRESSION

    PubMed Central

    CHENG, LINGYUN; TOYOGUCHI, MITSUKO; LOONEY, DAVID J.; LEE, JEFFERY; DAVIDSON, MARIE C.; FREEMAN, WILLIAM R.

    2006-01-01

    Purpose To evaluate the safety and efficiency of feline immunodeficiency virus (FIV) vectors for gene delivery into the mammalian retina. Methods A first-generation FIV vector was constructed and administered into rabbit eyes at two different concentrations by intravitreal or subretinal routes. A second-generation FIV vector was also constructed and administered subretinally into both rabbit and rat eyes at the same concentration. After vector administration, eyes were monitored using slit-lamp biomicroscopy, indirect ophthalmoscopy, fundus photography, and electroretinogram. After the rabbits were killed, eye tissues were processed for light microscopy and immunohistochemical analysis. Results Administration of both first- and second-generation FIV vectors produced transient vitritis and/or papillitis in rabbits, without other pathologic abnormalities. Retinal pigment epithelium (RPE) cells were the predominant cell type transduced in rabbit eyes, but ganglion cells and Müller cells were also transduced. Transduction was confined to the retinal bleb area. The second-generation FIV vector transduced RPE cells much more efficiently than the first-generation vector (95% vs. 4.5%, respectively; P = 0.0015) in rabbit eyes. In contrast, no toxicity was evident over a 24- to 25-month follow-up period after injection of the second-generation FIV vector into rat eyes. Tropism in the rat eye was similar, including RPE and ganglion cells, and the RPE transduction rate was also high (50%). Transgene expression was persistent in both species over the duration of the experiment. Conclusion Second-generation FIV vectors can efficiently transfer genes into RPE cells with resulting long-term expression, properties potentially valuable to gene therapy approaches to some retinal diseases. PMID:15689811

  9. Adenovirus Vectors for Gene Therapy, Vaccination and Cancer Gene Therapy

    PubMed Central

    Wold, William S.M.; Toth, Karoly

    2015-01-01

    Adenovirus vectors are the most commonly employed vector for cancer gene therapy. They are also used for gene therapy and as vaccines to express foreign antigens. Adenovirus vectors can be replication-defective; certain essential viral genes are deleted and replaced by a cassette that expresses a foreign therapeutic gene. Such vectors are used for gene therapy, as vaccines, and for cancer therapy. Replication-competent (oncolytic) vectors are employed for cancer gene therapy. Oncolytic vectors are engineered to replicate preferentially in cancer cells and to destroy cancer cells through the natural process of lytic virus replication. Many clinical trials indicate that replication-defective and replication-competent adenovirus vectors are safe and have therapeutic activity. PMID:24279313

  10. Retinitis Pigmentosa.

    ERIC Educational Resources Information Center

    Carr, Ronald E.

    1979-01-01

    The author describes the etiology of retinitis pigmentosa, a visual dysfunction which results from progressive loss of the retinal photoreceptors. Sections address signs and symptoms, ancillary findings, heredity, clinical diagnosis, therapy, and research. (SBH)

  11. Localization of a new autosomal dominant retinitis pigmentosa gene on chromosome 17p screeningof candidate genes

    SciTech Connect

    Greenberg, J.; Goliath, R.; Shugart, Y.Y.

    1994-09-01

    A new gene locus for autosomal dominant retinitis pigmentosa (ADRP) on 17p has been identified in a large South African (SA) family consisting of 28 living affected individuals in 4 successive generations. This is the first ADRP gene to be reported from SA. The human recoverin (RCVN) gene, which codes for a retinal-specific protein important in recovery to the dark state after visual excitation, has been mapped to 17p13.1 and was considered as a prime candidate gene for the disorder in this family. Mutation screening (using 8 different electrophoretic conditions to resolve heteroduplexes and SSCPs) did not produce any evidence of RCVN being involved in the pathogenesis of ADRP in this SA family. In addition, a mobility shift detected within exon 1 of the RCVN gene did not track with the ADRP phenotype. RP patients from 77 SA families and 30 normal individuals are being examined to establish the frequency of this polymorphism in the SA population. Highly polymorphic markers from 17p13 are now being sought in order to establish the minimum region containing this novel ADRP-SA gene. Two additional recently described retinal-expressed cDNAs, guanylyl cyclase and pigment epithelium-derived factor, which map to 17p13.1, will be tested for tight linkage to ADRP-SA.

  12. Apolipoprotein E gene polymorphisms and retinal vascular signs: The Atherosclerosis Risk in Communities (ARIC) Study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our objective was to examine the association between apolipoprotein E (APOE) gene polymorphisms and retinal microvascular signs. We used a population-based, cross-sectional study. Participants from the Atherosclerosis Risk in Communities Study (n=10,036; aged 49-73 years) had retinal photographs tak...

  13. Gene therapy progress and prospects: gene therapy for diabetes mellitus.

    PubMed

    Yechoor, V; Chan, L

    2005-01-01

    Diabetes mellitus has long been targeted, as yet unsuccessfully, as being curable with gene therapy. The main hurdles have not only been vector-related toxicity but also the lack of physiological regulation of the expressed insulin. Recent advances in understanding the developmental biology of beta-cells and the transcriptional cascade that drives it have enabled both in vivo and ex vivo gene therapy combined with cell therapy to be used in animal models of diabetes with success. The associated developments in the stem cell biology and immunology have opened up further opportunities for gene therapy to be applied to target autoimmune diabetes. PMID:15496957

  14. Retinitis Pigmentosa Treatment with Western Medicine and Traditional Chinese Medicine Therapies

    PubMed Central

    Xu, Jian; Peng, Qinghua

    2015-01-01

    Current management of retinitis pigmentosa (RP) includes an attempt at slowing down the degenerative process through therapies that use either Western or traditional Chinese medicine (TCM). Novel therapies in Western medicine (WM) include use of tailor-made gene therapy, transplantation of stem cells, or neuroprotection treatment. TCM treatment includes two major approaches. These are orally applied herbal decoctions and acupuncture. In fact, all TCM treatments are based on the differentiation of a symptom-complex, which is the characteristic essence of TCM. Thus, diagnosed RP may be treated via the liver, the kidney, and the spleen. The principle behind these treatments is to invigorate the blood and brighten the eyes by toning up the liver and the kidney. Also treatments to cope with deficiencies in the two concepts that are unique and fundamental to TCM are considered: Qi or “vital energy” and Yin and Yang or the harmony of all the opposite elements and forces that make up existence. In particular, the Qi deficiency that results from blood stasis is addressed in these treatments. This paper also puts forward the existing problems and the prospect of the future development on integrating TCM with WM. PMID:26124961

  15. A case of atypical progressive outer retinal necrosis after highly active antiretroviral therapy.

    PubMed

    Woo, Se Joon; Yu, Hyeong Gon; Chung, Hum

    2004-06-01

    This is a report of an atypical case of progressive outer retinal necrosis (PORN) and the effect of highly active antiretroviral therapy (HAART) on the clinical course of viral retinitis in an acquired immunodeficiency syndrome (AIDS) patient. A 22-year-old male patient infected with human immunodeficiency virus (HIV) presented with unilaterally reduced visual acuity and a dense cataract. After cataract extraction, retinal lesions involving the peripheral and macular areas were found with perivascular sparing and the mud-cracked, characteristic appearance of PORN. He was diagnosed as having PORN based on clinical features and was given combined antiviral treatment. With concurrent HAART, the retinal lesions regressed, with the regression being accelerated by further treatment with intravenous acyclovir and ganciclovir. This case suggests that HAART may change the clinical course of PORN in AIDS patients by improving host immunity. PORN should be included in the differential diagnosis of acute unilateral cataract in AIDS patients. PMID:15255240

  16. Inherited retinal diseases in dogs: advances in gene/mutation discovery

    PubMed Central

    Miyadera, Keiko

    2015-01-01

    1. Inherited retinal diseases (RDs) are vision-threatening conditions affecting humans as well as many domestic animals. Through many years of clinical studies of the domestic dog population, a wide array of RDs has been phenotypically characterized. Extensive effort to map the causative gene and to identify the underlying mutation followed. Through candidate gene, linkage analysis, genome-wide association studies, and more recently, by means of next-generation sequencing, as many as 31 mutations in 24 genes have been identified as the underlying cause for canine RDs. Most of these genes have been associated with human RDs providing opportunities to study their roles in the disease pathogenesis and in normal visual function. The canine model has also contributed in developing new treatments such as gene therapy which has been clinically applied to human patients. Meanwhile, with increasing knowledge of the molecular architecture of RDs in different subpopulations of dogs, the conventional understanding of RDs as a simple monogenic disease is beginning to change. Emerging evidence of modifiers that alters the disease outcome is complicating the interpretation of DNA tests. In this review, advances in the gene/mutation discovery approaches and the emerging genetic complexity of canine RDs are discussed. PMID:26120276

  17. A frameshift mutation in golden retriever dogs with progressive retinal atrophy endorses SLC4A3 as a candidate gene for human retinal degenerations.

    PubMed

    Downs, Louise M; Wallin-Håkansson, Berit; Boursnell, Mike; Marklund, Stefan; Hedhammar, Åke; Truvé, Katarina; Hübinette, Louise; Lindblad-Toh, Kerstin; Bergström, Tomas; Mellersh, Cathryn S

    2011-01-01

    Progressive retinal atrophy (PRA) in dogs, the canine equivalent of retinitis pigmentosa (RP) in humans, is characterised by vision loss due to degeneration of the photoreceptor cells in the retina, eventually leading to complete blindness. It affects more than 100 dog breeds, and is caused by numerous mutations. RP affects 1 in 4000 people in the Western world and 70% of causal mutations remain unknown. Canine diseases are natural models for the study of human diseases and are becoming increasingly useful for the development of therapies in humans. One variant, prcd-PRA, only accounts for a small proportion of PRA cases in the Golden Retriever (GR) breed. Using genome-wide association with 27 cases and 19 controls we identified a novel PRA locus on CFA37 (p(raw) = 1.94×10(-10), p(genome) = 1.0×10(-5)), where a 644 kb region was homozygous within cases. A frameshift mutation was identified in a solute carrier anion exchanger gene (SLC4A3) located within this region. This variant was present in 56% of PRA cases and 87% of obligate carriers, and displayed a recessive mode of inheritance with full penetrance within those lineages in which it segregated. Allele frequencies are approximately 4% in the UK, 6% in Sweden and 2% in France, but the variant has not been found in GRs from the US. A large proportion of cases (approximately 44%) remain unexplained, indicating that PRA in this breed is genetically heterogeneous and caused by at least three mutations. SLC4A3 is important for retinal function and has not previously been associated with spontaneously occurring retinal degenerations in any other species, including humans. PMID:21738669

  18. The retinal ciliopathies.

    PubMed

    Adams, N A; Awadein, Ahmed; Toma, Hassanain S

    2007-09-01

    While the functions of many of the proteins located in or associated with the photoreceptor cilia are poorly understood, disruption of the function of these proteins may result in a wide variety of phenotypes ranging from isolated retinal degeneration to more pleiotropic phenotypes. Systemic findings include neurosensory hearing loss, developmental delay, situs-inversus, infertility, disorders of limb and digit development, obesity, kidney disease, liver disease, and respiratory disease. The concept of "retinal ciliopathies" brings to attention the importance of further molecular analysis of this organelle as well as provides a potential common target for therapies for these disorders. The retinal ciliopathies include retinitis pigmentosa, macular degeneration, cone-dystrophy, cone-rod dystrophy, Leber congenital amaurosis, as well as retinal degenerations associated with Usher syndrome, primary ciliary dyskinesia, Senior-Loken syndrome, Joubert syndrome, Bardet-Biedl syndrome, Laurence-Moon syndrome, McKusick-Kaufman syndrome, and Biemond syndrome. Mutations for these disorders have been found in retinitis pigmentosa-1 (RP1), retinitis pigmentosa GTPase regulator (RPGR), retinitis pigmentosa GTPase regulator interacting protein (RPGR-IP), as well as the Usher, Bardet-Biedl, and nephronophthisis genes. Other systemic disorders associated with retinal degenerations that may also involve ciliary abnormalities include: Alstrom, Edwards-Sethi, Ellis-van Creveld, Jeune, Meckel-Gruber, Orofaciodigital Type 9, and Gurrieri syndromes. Understanding these conditions as ciliopathies may help the ophthalmologist to recognize associations between seemingly unrelated diseases and have a high degree of suspicion that a systemic finding may be present. PMID:17896309

  19. Gene therapy: progress and predictions

    PubMed Central

    Collins, Mary; Thrasher, Adrian

    2015-01-01

    The first clinical gene delivery, which involved insertion of a marker gene into lymphocytes from cancer patients, was published 25 years ago. In this review, we describe progress since then in gene therapy. Patients with some inherited single-gene defects can now be treated with their own bone marrow stem cells that have been engineered with a viral vector carrying the missing gene. Patients with inherited retinopathies and haemophilia B can also be treated by local or systemic injection of viral vectors. There are also a number of promising gene therapy approaches for cancer and infectious disease. We predict that the next 25 years will see improvements in safety, efficacy and manufacture of gene delivery vectors and introduction of gene-editing technologies to the clinic. Gene delivery may also prove a cost-effective method for the delivery of biological medicines. PMID:26702034

  20. Genomic Approaches For the Discovery of Genes Mutated in Inherited Retinal Degeneration

    PubMed Central

    Siemiatkowska, Anna M.; Collin, Rob W.J.; den Hollander, Anneke I.; Cremers, Frans P.M.

    2014-01-01

    In view of their high degree of genetic heterogeneity, inherited retinal diseases (IRDs) pose a significant challenge for identifying novel genetic causes. Thus far, more than 200 genes have been found to be mutated in IRDs, which together contain causal variants in >80% of the cases. Accurate genetic diagnostics is particularly important for isolated cases, in which X-linked and de novo autosomal dominant variants are not uncommon. In addition, new gene- or mutation-specific therapies are emerging, underlining the importance of identifying causative mutations in each individual. Sanger sequencing of selected genes followed by cost-effective targeted next-generation sequencing (NGS) can identify defects in known IRD-associated genes in the majority of the cases. Exome NGS in combination with genetic linkage or homozygosity mapping studies can aid the identification of the remaining causal genes. As these are thought to be mutated in <1% of the cases, validation through functional modeling in, for example, zebrafish and/or replication through the genotyping of large patient cohorts is required. In the near future, whole genome NGS in combination with transcriptome NGS may reveal mutations that are currently hidden in the noncoding regions of the human genome. PMID:24939053

  1. Gene Therapy for Lung Cancer.

    PubMed

    Lara-Guerra, Humberto; Roth, Jack A

    2016-01-01

    Gene therapy was originally conceived to treat monogenic diseases. The replacement of a defective gene with a functional gene can theoretically cure the disease. In cancer, multiple genetic defects are present and the molecular profile changes during the course of the disease, making the replacement of all defective genes impossible. To overcome these difficulties, various gene therapy strategies have been adopted, including immune stimulation, transfer of suicide genes, inhibition of driver oncogenes, replacement of tumor-suppressor genes that could mediate apoptosis or anti-angiogenesis, and transfer of genes that enhance conventional treatments such as radiotherapy and chemotherapy. Some of these strategies have been tested successfully in non-small-cell lung cancer patients and the results of laboratory studies and clinical trials are reviewed herein. PMID:27481008

  2. [Morphologic aspects of therapy-resistant cytomegalovirus retinitis].

    PubMed

    Meyer, P; Bernauer, W; Daicker, B; Zimmerli, W; Rüttimann, S

    1992-05-01

    Intravenous ganciclovir treatment was performed in eight male AIDS patients with primary unilateral CMV-retinitis. Three patients developed slowly progressive CMV-retinitis in the fellow eye despite adequate dose of ganciclovir. These different CMV-manifestations are shown in a sequence of fundus pictures. Three types of CMV-lesions were observed in connection with this study. Untreated central lesions showed the aspect of crumbled cheese and ketchup. Untreated lesions in the peripherie were yellowish-white, granular, "dry" and showed in most cases no haemorrhages. Lesions appearing during treatment showed initially "dry" white opaque subretinal areas, turning later on to the typical aspect of untreated lesions. The progression could not be stopped by highdose ganciclovir i.v. and thus bilateral blindness resulted after 12 to 22 months. The level of CD4-lymphocytes in the blood was diminished in all patients, but much more in patients with progressive disease. PMID:1319528

  3. PARP1 Gene Knock-Out Increases Resistance to Retinal Degeneration without Affecting Retinal Function

    PubMed Central

    Sahaboglu, Ayse; Tanimoto, Naoyuki; Kaur, Jasvir; Sancho-Pelluz, Javier; Huber, Gesine; Fahl, Edda; Arango-Gonzalez, Blanca; Zrenner, Eberhart; Ekström, Per; Löwenheim, Hubert; Seeliger, Mathias; Paquet-Durand, François

    2010-01-01

    Retinitis pigmentosa (RP) is a group of inherited neurodegenerative diseases affecting photoreceptors and causing blindness in humans. Previously, excessive activation of enzymes belonging to the poly-ADP-ribose polymerase (PARP) group was shown to be involved in photoreceptor degeneration in the human homologous rd1 mouse model for RP. Since there are at least 16 different PARP isoforms, we investigated the exact relevance of the predominant isoform - PARP1 - for photoreceptor cell death using PARP1 knock-out (KO) mice. In vivo and ex vivo morphological analysis using optic coherence tomography (OCT) and conventional histology revealed no major alterations of retinal phenotype when compared to wild-type (wt). Likewise, retinal function as assessed by electroretinography (ERG) was normal in PARP1 KO animals. We then used retinal explant cultures derived from wt, rd1, and PARP1 KO animals to test their susceptibility to chemically induced photoreceptor degeneration. Since photoreceptor degeneration in the rd1 retina is triggered by a loss-of-function in phosphodiesterase-6 (PDE6), we used selective PDE6 inhibition to emulate the rd1 situation on non-rd1 genotypes. While wt retina subjected to PDE6 inhibition showed massive photoreceptor degeneration comparable to rd1 retina, in the PARP1 KO situation, cell death was robustly reduced. Together, these findings demonstrate that PARP1 activity is in principle dispensable for normal retinal function, but is of major importance for photoreceptor degeneration under pathological conditions. Moreover, our results suggest that PARP dependent cell death or PARthanatos may play a major role in retinal degeneration and highlight the possibility to use specific PARP inhibitors for the treatment of RP. PMID:21124852

  4. Gene therapy on the move

    PubMed Central

    Kaufmann, Kerstin B; Büning, Hildegard; Galy, Anne; Schambach, Axel; Grez, Manuel

    2013-01-01

    The first gene therapy clinical trials were initiated more than two decades ago. In the early days, gene therapy shared the fate of many experimental medicine approaches and was impeded by the occurrence of severe side effects in a few treated patients. The understanding of the molecular and cellular mechanisms leading to treatment- and/or vector-associated setbacks has resulted in the development of highly sophisticated gene transfer tools with improved safety and therapeutic efficacy. Employing these advanced tools, a series of Phase I/II trials were started in the past few years with excellent clinical results and no side effects reported so far. Moreover, highly efficient gene targeting strategies and site-directed gene editing technologies have been developed and applied clinically. With more than 1900 clinical trials to date, gene therapy has moved from a vision to clinical reality. This review focuses on the application of gene therapy for the correction of inherited diseases, the limitations and drawbacks encountered in some of the early clinical trials and the revival of gene therapy as a powerful treatment option for the correction of monogenic disorders. PMID:24106209

  5. Bilateral loss of light reflex and accommodation following 360° peripheral retinal laser therapy.

    PubMed

    Jamil, Ahmad Zeeshan; Iqbal, Kashif; Gondal, Talat Mehmood; Iqbal, Wasim; Fawad-ur-Rahman; Mirza, Khurram Azam

    2012-07-01

    We report a case of bilateral loss of pupillary light reflex and accommodation following 360° peripheral retinal laser therapy. A 24 years old male underwent prophylactic laser barrage for peripheral retinal lattice degenerations. Soon after the procedure, he developed bilateral loss of pupillary light reflex and accommodation. The patient faced difficulty while doing near work. On instillation of 0.125% pilocarpine, both pupils demonstrated the phenomenon of denervation supersensitivity. Damage to the short ciliary nerves was the most likely mechanism responsible for this adverse outcome. PMID:22747871

  6. Progressive morphological changes and impaired retinal function associated with temporal regulation of gene expression after retinal ischemia/reperfusion injury in mice

    PubMed Central

    2013-01-01

    Retinal ischemia/reperfusion (I/R) injury is an important cause of visual impairment. However, questions remain on the overall I/R mechanisms responsible for progressive damage to the retina. In this study, we used a mouse model of I/R and characterized the pathogenesis by analyzing temporal changes of retinal morphology and function associated with changes in retinal gene expression. Transient ischemia was induced in one eye of C57BL/6 mice by raising intraocular pressure to 120 mmHg for 60 min followed by retinal reperfusion by restoring normal pressure. At various time points post I/R, retinal changes were monitored by histological assessment with H&E staining and by SD-OCT scanning. Retinal function was also measured by scotopic ERG. Temporal changes in retinal gene expression were analyzed using cDNA microarrays and real-time RT-PCR. In addition, retinal ganglion cells and gliosis were observed by immunohistochemistry. H&E staining and SD-OCT scanning showed an initial increase followed by a significant reduction of retinal thickness in I/R eyes accompanied with cell loss compared to contralateral control eyes. The greatest reduction in thickness was in the inner plexiform layer (IPL) and inner nuclear layer (INL). Retinal detachment was observed at days 3 and 7 post- I/R injury. Scotopic ERG a- and b-wave amplitudes and implicit times were significantly impaired in I/R eyes compared to contralateral control eyes. Microarray data showed temporal changes in gene expression involving various gene clusters such as molecular chaperones and inflammation. Furthermore, immunohistochemical staining confirmed Müller cell gliosis in the damaged retinas. The time-dependent changes in retinal morphology were significantly associated with functional impairment and altered retinal gene expression. We demonstrated that I/R-mediated morphological changes the retina closely associated with functional impairment as well as temporal changes in retinal gene expression. Our

  7. Vectors for cancer gene therapy.

    PubMed

    Zhang, J; Russell, S J

    1996-09-01

    Many viral and non-viral vector systems have now been developed for gene therapy applications. In this article, the pros and cons of these vector systems are discussed in relation to the different cancer gene therapy strategies. The protocols used in cancer gene therapy can be broadly divided into six categories including gene transfer to explanted cells for use as cell-based cancer vaccines; gene transfer to a small number of tumour cells in situ to achieve a vaccine effect; gene transfer to vascular endothelial cells (VECs) lining the blood vessels of the tumour to interfere with tumour angiogenesis; gene transfer to T lymphocytes to enhance their antitumour effector capability; gene transfer to haemopoietic stem cells (HSCs) to enhance their resistance to cytotoxic drugs and gene transfer to a large number of tumour cells in situ to achieve nonimmune tumour reduction with or without bystander effect. Each of the six strategies makes unique demands on the vector system and these are discussed with reference to currently available vectors. Aspects of vector biology that are in need of further development are discussed in some detail. The final section points to the potential use of replicating viruses as delivery vehicles for efficient in vivo gene transfer to disseminated cancers. PMID:9034598

  8. Perspectives on Best Practices for Gene Therapy Programs

    PubMed Central

    Cheever, Thomas R.; Berkley, Dale; Braun, Serge; Brown, Robert H.; Byrne, Barry J.; Chamberlain, Jeffrey S.; Cwik, Valerie; Duan, Dongsheng; Federoff, Howard J.; High, Katherine A.; Kaspar, Brian K.; Klinger, Katherine W.; Larkindale, Jane; Lincecum, John; Mavilio, Fulvio; McDonald, Cheryl L.; McLaughlin, James; Weiss McLeod, Bonnie; Mendell, Jerry R.; Nuckolls, Glen; Stedman, Hansell H.; Tagle, Danilo A.; Vandenberghe, Luk H.; Wang, Hao; Wernett, Pamela J.; Wilson, James M.; Porter, John D.

    2015-01-01

    Abstract With recent successes in gene therapy trials for hemophilia and retinal diseases, the promise and prospects for gene therapy are once again garnering significant attention. To build on this momentum, the National Institute of Neurological Disorders and Stroke and the Muscular Dystrophy Association jointly hosted a workshop in April 2014 on “Best Practices for Gene Therapy Programs,” with a focus on neuromuscular disorders. Workshop participants included researchers from academia and industry as well as representatives from the regulatory, legal, and patient advocacy sectors to cover the gamut from preclinical optimization to intellectual property concerns and regulatory approval. The workshop focused on three key issues in the field: (1) establishing adequate scientific premise for clinical trials in gene therapy, (2) addressing regulatory process issues, and (3) intellectual property and commercialization issues as they relate to gene therapy. The outcomes from the discussions at this workshop are intended to provide guidance for researchers and funders in the gene therapy field. PMID:25654329

  9. Combination anti-VEGF and corticosteroid therapy for idiopathic retinal vasculitis, aneurysms, and neuroretinitis syndrome.

    PubMed

    Sawhney, Gagan K; Payne, John F; Ray, Robin; Mehta, Sonia; Bergstrom, Chris S; Yeh, Steven

    2013-11-01

    Vision loss associated with the idiopathic retinal vasculitis, aneurysms, and neuroretinitis (IRVAN) syndrome most commonly occurs from macular edema or complications related to neovascularization. The authors present a case of advanced IRVAN associated with a massive exudative response characterized by peripheral retinal telangiectasias, exudative retinal detachment, and macular edema with lipid maculopathy. The patient was managed successfully with visual acuity from hand motion to 20/150 using a combination of local corticosteroids, intravitreal bevacizumab, panretinal photocoagulation, and eventually pars plana vitrectomy for progressive vitreomacular traction. VEGF- and non-VEGF-mediated mechanisms appear to be involved in the pathogenesis of IRVAN given the efficacy of combination therapy. [ophthalmic surg lasers imaging retina. 2013;44:599-602.]. PMID:24221466

  10. Gene Therapy for Cartilage Repair

    PubMed Central

    Madry, Henning; Orth, Patrick; Cucchiarini, Magali

    2011-01-01

    The concept of using gene transfer strategies for cartilage repair originates from the idea of transferring genes encoding therapeutic factors into the repair tissue, resulting in a temporarily and spatially defined delivery of therapeutic molecules to sites of cartilage damage. This review focuses on the potential benefits of using gene therapy approaches for the repair of articular cartilage and meniscal fibrocartilage, including articular cartilage defects resulting from acute trauma, osteochondritis dissecans, osteonecrosis, and osteoarthritis. Possible applications for meniscal repair comprise meniscal lesions, meniscal sutures, and meniscal transplantation. Recent studies in both small and large animal models have demonstrated the applicability of gene-based approaches for cartilage repair. Chondrogenic pathways were stimulated in the repair tissue and in osteoarthritic cartilage using genes for polypeptide growth factors and transcription factors. Although encouraging data have been generated, a successful translation of gene therapy for cartilage repair will require an ongoing combined effort of orthopedic surgeons and of basic scientists. PMID:26069580

  11. Gene Therapy in Heart Failure

    PubMed Central

    Vinge, Leif Erik; Raake, Philip W.; Koch, Walter J.

    2008-01-01

    With increasing knowledge of basic molecular mechanisms governing the development of heart failure (HF), the possibility of specifically targeting key pathological players is evolving. Technology allowing for efficient in vivo transduction of myocardial tissue with long-term expression of a transgene enables translation of basic mechanistic knowledge into potential gene therapy approaches. Gene therapy in HF is in its infancy clinically with the predominant amount of experience being from animal models. Nevertheless, this challenging and promising field is gaining momentum as recent preclinical studies in larger animals have been carried out and, importantly, there are 2 newly initiated phase I clinical trials for HF gene therapy. To put it simply, 2 parameters are needed for achieving success with HF gene therapy: (1) clearly identified detrimental/beneficial molecular targets; and (2) the means to manipulate these targets at a molecular level in a sufficient number of cardiac cells. However, several obstacles do exist on our way to efficient and safe gene transfer to human myocardium. Some of these obstacles are discussed in this review; however, it primarily focuses on the molecular target systems that have been subjected to intense investigation over the last decade in an attempt to make gene therapy for human HF a reality. PMID:18566312

  12. Gene Therapy for Cardiovascular Disease

    PubMed Central

    2003-01-01

    The last decade has seen substantial advances in the development of gene therapy strategies and vector technology for the treatment of a diverse number of diseases, with a view to translating the successes observed in animal models into the clinic. Perhaps the overwhelming drive for the increase in vascular gene transfer studies is the current lack of successful long-term pharmacological treatments for complex cardiovascular diseases. The increase in cardiovascular disease to epidemic proportions has also led many to conclude that drug therapy may have reached a plateau in its efficacy and that gene therapy may represent a realistic solution to a long-term problem. Here, we discuss gene delivery approaches and target diseases. PMID:12721517

  13. Facile Noninvasive Retinal Gene Delivery Enabled by Penetratin.

    PubMed

    Liu, Chang; Jiang, Kuan; Tai, Lingyu; Liu, Yu; Wei, Gang; Lu, Weiyue; Pan, Weisan

    2016-08-01

    Gene delivery to the posterior segment of the eye is severely hindered by the impermeability of defensive barriers; therefore, in clinical settings, genomic medicines are mainly administered by intravitreal injection. We previously found that penetratin could transport the covalently conjugated fluorophore to the fundus oculi by topical instillation. In this study, gene delivery systems enabled by penetratin were designed based on electrostatic binding to target the retina via a noninvasive administration route and prepared with red fluorescent protein plasmid (pRFP) and/or poly(amidoamine) dendrimer of low molecular weight (G3 PAMAM). Formulation optimization, structure confirmation, and characterization were subsequently conducted. Penetratin alone showed limited ability to condense the plasmid but had powerful uptake and transfection by corneal and conjunctival cells. G3 PAMAM was nontoxic to the ocular cells, and when introduced into the penetratin-incorporated complex, the plasmid was condensed more compactly. Therefore, further improved cellular uptake and transfection were observed. After being instilled in the conjunctival sac of rats, the intact complexes penetrated rapidly from the ocular surface into the fundus and resided in the retina for more than 8 h, which resulted in efficient expression of RFP in the posterior segment. Intraocular distribution of the complexes suggested that the plasmids were absorbed into the eyes through a noncorneal pathway during which penetratin played a crucial role. This study provides a facile and friendly approach for intraocular gene delivery and is an important step toward the development of noninvasive gene therapy for posterior segment diseases. PMID:27400087

  14. Investigation of SLA4A3 as a candidate gene for human retinal disease.

    PubMed

    Downs, Louise M; Webster, Andrew R; Moore, Anthony T; Michaelides, Michel; Ali, Robin R; Hardcastle, Alison J; Mellersh, Cathryn S

    2016-01-01

    SLC4A3 has been shown to cause retinal degeneration in a genetically engineered knockout mouse, and in a naturally occurring form of canine progressive retinal atrophy considered to be the equivalent of retinitis pigmentosa in humans (RP). This study was undertaken to investigate if SLC4A3 coding variants were implicated in human retinal degeneration. SLC4A3 exons were amplified and sequenced in 200 patients with autosomal recessive retinal degeneration who had no known molecular diagnosis for their condition, which included 197 unrelated individuals with suspected RP and three individuals with other forms of retinal disease. Three rare variants were identified that were predicted to be potentially pathogenic, however each variant was heterozygous in a single patient and therefore not considered disease-causing in isolation. Of these three variants, SNP-3 was the rarest, with an allele frequency of 7.06 x 10(-5) (>46,000 exomes from the ExAC database). In conclusion, no compound heterozygous or homozygous potentially pathogenic variants were identified that would account for recessive RP or retinal degeneration in this cohort, however the possibility remains that the rare variants identified could be acting with as yet undiscovered mutations in introns or regulatory regions. SLC4A3 remains an excellent candidate gene for human retinal degeneration, and with the advent of whole exome and whole genome sequencing of cohorts of molecularly unsolved patients with syndromic and non-syndromic forms of retinal degeneration, SLC4A3 may yet be implicated in human disease. PMID:27211793

  15. Retinal complications with elevated circulating plasma C5a associated with interferon-alpha therapy for chronic active hepatitis C.

    PubMed

    Sugano, S; Yanagimoto, M; Suzuki, T; Sato, M; Onmura, H; Aizawa, H; Makino, H

    1994-11-01

    Retinal hemorrhage is a complication of interferon therapy of unknown pathogenesis. We report two chronic active hepatitis C patients who developed retinal hemorrhage and/or cotton wool patches during interferon-alpha therapy 4 and 12 wk after beginning treatment. At the time of the hemorrhage, plasma-activated complement 5, a known potent intravascular aggregator of granulocytes, increased to 54 ng/ml in one patient and to 29 ng/ml in the other patient. When the hemorrhage resolved, it decreased to under 5 ng/ml. Our cases suggest that complement activation occurs in patients treated with interferon-alpha and that activation of complement 5 can lead to retinal capillary infarction and retinal hemorrhage. High levels of activated complement 5 may predict retinal artery infarction or perhaps microvascular emboli in the other organs. PMID:7942735

  16. Gene Therapy in Corneal Transplantation

    PubMed Central

    Qazi, Yureeda; Hamrah, Pedram

    2014-01-01

    Corneal transplantation is the most commonly performed organ transplantation. Immune privilege of the cornea is widely recognized, partly because of the relatively favorable outcome of corneal grafts. The first-time recipient of corneal allografts in an avascular, low-risk setting can expect a 90% success rate without systemic immunosuppressive agents and histocompatibility matching. However, immunologic rejection remains the major cause of graft failure, particularly in patients with a high risk for rejection. Corticosteroids remain the first-line therapy for the prevention and treatment of immune rejection. However, current pharmacological measures are limited in their side-effect profiles, repeated application, lack of targeted response, and short duration of action. Experimental ocular gene therapy may thus present new horizons in immunomodulation. From efficient viral vectors to sustainable alternative splicing, we discuss the progress of gene therapy in promoting graft survival and postulate further avenues for gene-mediated prevention of allogeneic graft rejection. PMID:24138037

  17. Vision from next generation sequencing: multi-dimensional genome-wide analysis for producing gene regulatory networks underlying retinal development, aging and disease.

    PubMed

    Yang, Hyun-Jin; Ratnapriya, Rinki; Cogliati, Tiziana; Kim, Jung-Woong; Swaroop, Anand

    2015-05-01

    Genomics and genetics have invaded all aspects of biology and medicine, opening uncharted territory for scientific exploration. The definition of "gene" itself has become ambiguous, and the central dogma is continuously being revised and expanded. Computational biology and computational medicine are no longer intellectual domains of the chosen few. Next generation sequencing (NGS) technology, together with novel methods of pattern recognition and network analyses, has revolutionized the way we think about fundamental biological mechanisms and cellular pathways. In this review, we discuss NGS-based genome-wide approaches that can provide deeper insights into retinal development, aging and disease pathogenesis. We first focus on gene regulatory networks (GRNs) that govern the differentiation of retinal photoreceptors and modulate adaptive response during aging. Then, we discuss NGS technology in the context of retinal disease and develop a vision for therapies based on network biology. We should emphasize that basic strategies for network construction and analyses can be transported to any tissue or cell type. We believe that specific and uniform guidelines are required for generation of genome, transcriptome and epigenome data to facilitate comparative analysis and integration of multi-dimensional data sets, and for constructing networks underlying complex biological processes. As cellular homeostasis and organismal survival are dependent on gene-gene and gene-environment interactions, we believe that network-based biology will provide the foundation for deciphering disease mechanisms and discovering novel drug targets for retinal neurodegenerative diseases. PMID:25668385

  18. Gene therapy for Parkinson's disease.

    PubMed

    Lawlor, Patricia A; During, Matthew J

    2004-03-01

    Parkinson's disease (PD) is a debilitating neurodegenerative disorder arising from loss of dopaminergic neurons in the substantia nigra pars compacta and subsequent depletion of striatal dopamine levels, which results in distressing motor symptoms. The current standard pharmacological treatment for PD is direct replacement of dopamine by treatment with its precursor, levodopa (L-dopa). However, this does not significantly alter disease progression and might contribute to the ongoing pathology. Several features of PD make this disease one of the most promising targets for clinical gene therapy of any neurological disease. The confinement of the major pathology to a compact, localised neuronal population and the anatomy of the basal ganglia circuitry mean that global gene transfer is not required and there are well-defined sites for gene transfer. The multifactorial aetiology of idiopathic PD means that it is unlikely any single gene will cure the disease, and as a result at least three separate gene-transfer strategies are currently being pursued: transfer of genes for enzymes involved in dopamine production; transfer of genes for growth factors involved in dopaminergic cell survival and regeneration; and transfer of genes to reset neuronal circuitry by switching cellular phenotype. The merits of these strategies are discussed here, along with remaining hurdles that might impede transfer of gene therapy technology to the clinic as a treatment for PD. PMID:15000692

  19. [Review of cancer gene therapy].

    PubMed

    Tani, K

    2000-09-01

    Since the first introduction of gene-marking technology to the clinical field in 1989 by Rosenberg et al, more than 4,000 patients have participated gene therapy clinical trials worldwide. Most of those patients had malignancies. Nearly 90% of clinical trials, however, are still in phase I-II stage, and only 3 protocols are in the phase III stage in early 2000. As current clinical gene therapy protocols are intended essentially to examine the safety and feasibility of the new strategy, more careful and steady steps may be required before these clinical trials really produce clinical benefits. Focused on cancer gene therapy, direct and indirect approaches are undertaken. In the direct approach, HSV-TK, HLA-B7, or p53 tumor suppressor gene therapies are the three major approaches historically. In for the indirect approach, cytokine or adhesion molecule gene-transferred tumor cells or immunocompetent cells are considered to be promising to enhance patients' antitumor immunity. In particular, we have concentrated on developing immuno gene therapy using GM-CSF-transduced autologous tumor cells. We have already recruited three patients with stage IV renal cell cancer. In all patients, peripheral blood T cells were mobilized after vaccination with GM-CSF-transduced tumor cells, and two of the three patients showed the persistence of cytotoxic T cells against autologous tumor cells. Clinically, one patient has been followed up with stable disease for more than one year since the start of vaccination. Further clinical studies are required to obtain conclusive results. PMID:11022677

  20. Gene therapy for paediatric leukaemia.

    PubMed

    Rousseau, R F; Bollard, C M; Heslop, H E

    2001-07-01

    Improvements in the chemotherapeutic and transplant regimens have had a significant impact in improving survival rates for paediatric leukaemia. However, there are still important problems to address including what options are available for patients with chemoresistant disease and what strategies are available to avoid the concerns regarding the toxicity associated with highly cytotoxic treatment regimens. Gene therapy and immunotherapy protocols hold great promise. Using gene transfer of a marker gene, a number of biological issues in the therapy of leukaemia have been addressed. For example, by gene marking autologous bone marrow grafts it has been possible to demonstrate that infused marrow contributes to relapse in acute and chronic myeloid leukaemias. In the allogeneic transplant setting, genetically modified T-cells have proven valuable for the prophylaxis and treatment of viral diseases and may have an important role in preventing or treating disease relapse. Gene transfer is also being used to modify tumour function, enhance immunogenicity, and confer drug-resistance to normal haematopoietic stem cells. With the continued scientific advancements in this field, gene therapy will almost certainly have a major impact on the treatment of paediatric leukaemia in the future. PMID:11727502

  1. Experimental therapies: gene therapies and oncolytic viruses.

    PubMed

    Hulou, M Maher; Cho, Choi-Fong; Chiocca, E Antonio; Bjerkvig, Rolf

    2016-01-01

    Glioblastoma is the most common and aggressive primary brain tumor in adults. Over the past three decades, the overall survival time has only improved by a few months, therefore novel alternative treatment modalities are needed to improve clinical management strategies. Such strategies should ultimately extend patient survival. At present, the extensive insight into the molecular biology of gliomas, as well as into genetic engineering techniques, has led to better decision processes when it comes to modifying the genome to accommodate suicide genes, cytokine genes, and tumor suppressor genes that may kill cancer cells, and boost the host defensive immune system against neoantigenic cytoplasmic and nuclear targets. Both nonreplicative viral vectors and replicating oncolytic viruses have been developed for brain cancer treatment. Stem cells, microRNAs, nanoparticles, and viruses have also been designed. These have been armed with transgenes or peptides, and have been used both in laboratory-based experiments as well as in clinical trials, with the aim of improving selective killing of malignant glioma cells while sparing normal brain tissue. This chapter reviews the current status of gene therapies for malignant gliomas and highlights the most promising viral and cell-based strategies under development. PMID:26948355

  2. Vision from next generation sequencing: Multi-dimensional genome-wide analysis for producing gene regulatory networks underlying retinal development, aging and disease

    PubMed Central

    Yang, Hyun-Jin; Ratnapriya, Rinki; Cogliati, Tiziana; Kim, Jung-Woong; Swaroop, Anand

    2015-01-01

    Genomics and genetics have invaded all aspects of biology and medicine, opening uncharted territory for scientific exploration. The definition of “gene” itself has become ambiguous, and the central dogma is continuously being revised and expanded. Computational biology and computational medicine are no longer intellectual domains of the chosen few. Next generation sequencing (NGS) technology, together with novel methods of pattern recognition and network analyses, has revolutionized the way we think about fundamental biological mechanisms and cellular pathways. In this review, we discuss NGS-based genome-wide approaches that can provide deeper insights into retinal development, aging and disease pathogenesis. We first focus on gene regulatory networks (GRNs) that govern the differentiation of retinal photoreceptors and modulate adaptive response during aging. Then, we discuss NGS technology in the context of retinal disease and develop a vision for therapies based on network biology. We should emphasize that basic strategies for network construction and analyses can be transported to any tissue or cell type. We believe that specific and uniform guidelines are required for generation of genome, transcriptome and epigenome data to facilitate comparative analysis and integration of multi-dimensional data sets, and for constructing networks underlying complex biological processes. As cellular homeostasis and organismal survival are dependent on gene-gene and gene-environment interactions, we believe that network-based biology will provide the foundation for deciphering disease mechanisms and discovering novel drug targets for retinal neurodegenerative diseases. PMID:25668385

  3. Ethics of Gene Therapy Debated.

    ERIC Educational Resources Information Center

    Borman, Stu

    1991-01-01

    Presented are the highlights of a press conference featuring biomedical ethicist LeRoy Walters of Georgetown University and attorney Andrew Kimbrell of the Foundation on Economic Trends. The opposing points of view of these two speakers serve to outline the pros and cons of the gene therapy issue. (CW)

  4. [Gene therapy for osteoarticular disorders].

    PubMed

    Gouze, Jean-Noël; Evans, Christopher H; Ghivizzani, Steven C; Gouze, Elvire

    2007-03-01

    Osteoarticular disorders are the major cause of disability in Europe and North America. It is estimated that rheumatoid arthritis affects 1 % of the population and that more than two third of people over age 55 develop osteoarthritis. Because there are no satisfactory treatments, gene therapy offers a new therapeutic approach. The delivery of cDNA encoding anti-arthritic proteins to articular cells has shown therapeutic efficacy in numerous animal models in vivo. Through the development and the experimental progresses that have been made for both rheumatoid arthritis and osteoarthritis, this review discusses the different gene therapy strategies available today and the safety issues with which they may be associated. Among the different vectors available today, adeno-associated virus seems the best candidate for a direct in vivo gene delivery approach for the treatment of joint disorders. PMID:17349293

  5. Gene Therapy for Coagulation Disorders.

    PubMed

    Swystun, Laura L; Lillicrap, David

    2016-04-29

    Molecular genetic details of the human coagulation system were among the first successes of the genetic revolution in the 1980s. This information led to new molecular diagnostic strategies for inherited disorders of hemostasis and the development of recombinant clotting factors for the treatment of the common inherited bleeding disorders. A longer term goal of this knowledge has been the establishment of gene transfer to provide continuing access to missing or defective hemostatic proteins. Because of the relative infrequency of inherited coagulation factor disorders and the availability of safe and effective alternative means of management, the application of gene therapy for these conditions has been slow to realize clinical application. Nevertheless, the tools for effective and safe gene transfer are now much improved, and we have started to see examples of clinical gene therapy successes. Leading the way has been the use of adeno-associated virus-based strategies for factor IX gene transfer in hemophilia B. Several small phase 1/2 clinical studies using this approach have shown prolonged expression of therapeutically beneficial levels of factor IX. Nevertheless, before the application of gene therapy for coagulation disorders becomes widespread, several obstacles need to be overcome. Immunologic responses to the vector and transgenic protein need to be mitigated, and production strategies for clinical grade vectors require enhancements. There is little doubt that with the development of more efficient and facile strategies for genome editing and the application of other nucleic acid-based approaches to influence the coagulation system, the future of genetic therapies for hemostasis is bright. PMID:27126652

  6. Gene Therapy and Children (For Parents)

    MedlinePlus

    ... screenings or other regular exams. previous continue The Future of Gene Therapy To cure genetic diseases, scientists ... Gene therapy's potential to revolutionize medicine in the future is exciting, and hopes are high for its ...

  7. Safety and Efficacy of Human Wharton's Jelly-Derived Mesenchymal Stem Cells Therapy for Retinal Degeneration

    PubMed Central

    Leow, S. N.; Luu, Chi D.; Hairul Nizam, M. H.; Mok, P. L.; Ruhaslizan, R.; Wong, H. S.; Wan Abdul Halim, Wan Haslina; Ng, M. H.; Ruszymah, B. H. I.; Chowdhury, S. R.; Bastion, M. L. C.; Then, K. Y.

    2015-01-01

    Purpose To investigate the safety and efficacy of subretinal injection of human Wharton’s Jelly-derived mesenchymal stem cells (hWJ-MSCs) on retinal structure and function in Royal College of Surgeons (RCS) rats. Methods RCS rats were divided into 2 groups: hWJ-MSCs treated group (n = 8) and placebo control group (n = 8). In the treatment group, hWJ-MSCs from healthy donors were injected into the subretinal space in one eye of each rat at day 21. Control group received saline injection of the same volume. Additional 3 animals were injected with nanogold-labelled stem cells for in vivo tracking of cells localisation using a micro-computed tomography (microCT). Retinal function was assessed by electroretinography (ERG) 3 days before the injection and repeated at days 15, 30 and 70 after the injection. Eyes were collected at day 70 for histology, cellular and molecular studies. Results No retinal tumor formation was detected by histology during the study period. MicroCT scans showed that hWJ-MSCs stayed localised in the eye with no systemic migration. Transmission electron microscopy showed that nanogold-labelled cells were located within the subretinal space. Histology showed preservation of the outer nuclear layer (ONL) in the treated group but not in the control group. However, there were no significant differences in the ERG responses between the groups. Confocal microscopy showed evidence of hWJ-MSCs expressing markers for photoreceptor, Müller cells and bipolar cells. Conclusions Subretinal injection of hWJ-MSCs delay the loss of the ONL in RCS rats. hWJ-MSCs appears to be safe and has potential to differentiate into retinal-like cells. The potential of this cell-based therapy for the treatment of retinal dystrophies warrants further studies. PMID:26107378

  8. [Realities and hopes of gene therapy].

    PubMed

    Zdanov, R I; Semenova, N V; Archakov, A I

    2000-01-01

    The work represents an introduction article of editors of special issue of the magazine devoted to gene therapy and therapeutics. The main results of clinical gene therapy in the past decade are critically considered in connection with a changes of paradigms of the field. They are: 1) change of the main target of genetic therapy--correction of defects in chromosomes--onto expression and/or output of target genes for gene therapy; 2) transfer from gene transplantation to cell transplantation; 3) tendency for the use of safe/non-viral vectors instead of viral ones.; and 4) conflict of interests in gene therapy. Outlooks in the field are discussed. PMID:11033881

  9. Gene delivery and expression in human retinal pigment epithelial cells: effects of synthetic carriers, serum, extracellular matrix and viral promoters.

    PubMed

    Urtti, A; Polansky, J; Lui, G M; Szoka, F C

    2000-01-01

    Non-viral gene therapy is a potential treatment to many incurable retinal diseases. To fulfill this promise, plasmid DNA must be delivered to the retinal target cells. We evaluated the efficacy of synthetic DNA complexing compounds in transfecting primary human retinal pigment epithelial (RPE) cells in vitro. Fetal human RPE cells were cultured with or without extracellular matrix (ECM), produced using calf corneal endothelial cells. Plasmids encoding nuclear localizing beta galactosidase or luciferase (pRSVLuc, pCLuc4, pSV2Luc) were complexed in water at various +/- charge ratios using cationic lipids (Lipofectin, DOTAP, DOGS), polyethylene imines (25 and 750 kDa), and with degraded 6th generation starburst polyamidoamine dendrimers. Luciferase was quantified using a luminometric assay and beta galactosidase with X-gal staining. Toxicities of transfections were evaluated with the MTT-assay. Using beta galactosidase as the reporter gene naked DNA did not transfect RPE cells at measurable levels whereas 1-5% of the cells expressed histochemically detectable amounts of the gene after transfection with cationic lipid DNA complexes. In RPE cells, Rous sarcoma virus and cytomegalovirus (CMV) were more efficient promoters than SV40 in driving luciferase expression, and CMV was chosen for further experiments. At optimal complex charge ratios, expression levels of luciferase were > 10(9) light units/mg protein after transfection using dendrimers and PEI25, while transfection mediated with the other carriers resulted in luciferase expression levels of 10(7)-10(9) light units/mg protein or less. In general, dendrimers and large molecular weight PEI were less toxic than cationic lipids or PEI25 to RPE cells. Serum and ECM decreased gene expression to the RPE cells with all carriers. Despite low percentage of transfected cells the transgene expression per RPE cell is high, important feature in the retinal tissue with small dimensions, in particular in the case of secreted gene

  10. Retinal Cell Responses to Elevated Intraocular Pressure: A Gene Array Comparison between the Whole Retina and Retinal Ganglion Cell Layer

    PubMed Central

    Guo, Ying; Cepurna, William O.; Dyck, Jennifer A.; Doser, Tom A.; Johnson, Elaine C.

    2010-01-01

    Purpose. To determine and compare gene expression patterns in the whole retina and retinal ganglion cell layer (RGCL) in a rodent glaucoma model. Methods. IOP was unilaterally elevated in Brown Norway rats (N = 26) by injection of hypertonic saline and monitored for 5 weeks. A cDNA microarray was used on whole retinas from one group of eyes with extensive optic nerve injury and on RGCL isolated by laser capture microdissection (LCM) from another group with comparable injury, to determine the significantly up- or downregulated genes and gene categories in both groups. Expression changes of selected genes were examined by quantitative reverse transcription-PCR (qPCR) to verify microarray results. Results. Microarray analysis of the whole retina identified 632 genes with significantly changed expression (335 up, 297 down), associated with 9 upregulated and 3 downregulated biological processes. In contrast, the RGCL microarray yielded 3726 genes with significantly changed expression (2003 up, 1723 down), including 60% of those found in whole retina. Thirteen distinct upregulated biological processes were identified in the RGCL, dominated by protein synthesis. Among 11 downregulated processes, axon extension and dendrite morphogenesis and generation of precursor metabolism and energy were uniquely identified in the RGCL. qPCR confirmed significant changes in 6 selected messages in whole retina and 11 in RGCL. Increased Atf3, the most upregulated gene in the RGCL, was confirmed by immunohistochemistry of RGCs. Conclusions. Isolation of RGCL by LCM allows a more refined detection of gene response to elevated pressure and improves the potential of determining cellular mechanisms in RGCs and their supporting cells that could be targets for enhancing RGC survival. PMID:20071680

  11. Muscle Gene Therapy for Hemophilia

    PubMed Central

    Sabatino, Denise E.; Arruda, Valder R.

    2013-01-01

    Muscle-directed gene therapy for hemophilia is an attractive strategy for expression of therapeutic levels of clotting factor as evident from preclinical studies and an early phase clinical trial. Notably, local FIX expression by AAV-mediated direct intramuscular injection to skeletal muscle persists for years. Development of intravascular delivery of AAV vector approaches to skeletal muscle resulted in vector in widespread areas of the limb and increased expression of FIX in hemophilia B dogs. The use of FIX variants with improved biological activity may provide the opportunity to increase the efficacy of these approaches. Studies for hemophilia A are less developed at this point, but utilizing transgenes that improve hemostasis independent of FIX and FVIII has potential therapeutic application for both hemophilia A and B. Continuous monitoring of humoral and T cell responses to the transgene and AAV capsid in human trials will be critical for the translation of these promising approaches for muscle gene therapy for hemophilia. PMID:24883231

  12. Photoreceptor Rescue by an Abbreviated Human RPGR Gene in a Murine Model of X-linked Retinitis Pigmentosa

    PubMed Central

    Pawlyk, Basil S.; Adamian, Michael; Sun, Xun; Bulgakov, Oleg V.; Shu, Xinhua; Smith, Alexander J.; Berson, Eliot L.; Ali, Robin R.; Khani, Shahrokh; F.Wright, Alan; Sandberg, Michael A.; Li, Tiansen

    2015-01-01

    The X-linked RP3 gene codes for the ciliary protein RPGR and accounts for over 10% of inherited retinal degenerations. The critical RPGR-ORF15 splice variant contains a highly repetitive purine-rich linker region that renders it unstable and difficult to adapt for gene therapy. To test the hypothesis that the precise length of the linker region is not critical for function, we evaluated whether AAV-mediated replacement gene therapy with a human ORF15 variant containing in-frame shortening of the linker region could reconstitute RPGR function in vivo. We delivered human RPGR-ORF15 replacement genes with deletion of most (314-codons, “short form”) or 1/3 (126-codons, “long form”) of the linker region to Rpgr null mice. Human RPGR-ORF15 expression was detected post-treatment with both forms of ORF15 transgenes. However, only the long form correctly localized to the connecting cilia and led to significant functional and morphological rescue of rods and cones. Thus the highly repetitive region of RPGR is functionally important but that moderate shortening of its length, which confers the advantage of added stability, preserves its function. These findings provide a theoretical basis for optimizing replacement gene design in clinical trials for X-linked RP3. PMID:26348595

  13. Replication-dependent histone genes are actively transcribed in differentiating and aging retinal neurons.

    PubMed

    Banday, Abdul Rouf; Baumgartner, Marybeth; Al Seesi, Sahar; Karunakaran, Devi Krishna Priya; Venkatesh, Aditya; Congdon, Sean; Lemoine, Christopher; Kilcollins, Ashley M; Mandoiu, Ion; Punzo, Claudio; Kanadia, Rahul N

    2014-01-01

    In the mammalian genome, each histone family contains multiple replication-dependent paralogs, which are found in clusters where their transcription is thought to be coupled to the cell cycle. Here, we wanted to interrogate the transcriptional regulation of these paralogs during retinal development and aging. We employed deep sequencing, quantitative PCR, in situ hybridization (ISH), and microarray analysis, which revealed that replication-dependent histone genes were not only transcribed in progenitor cells but also in differentiating neurons. Specifically, by ISH analysis we found that different histone genes were actively transcribed in a subset of neurons between postnatal day 7 and 14. Interestingly, within a histone family, not all paralogs were transcribed at the same level during retinal development. For example, expression of Hist1h1b was higher embryonically, while that of Hist1h1c was higher postnatally. Finally, expression of replication-dependent histone genes was also observed in the aging retina. Moreover, transcription of replication-dependent histones was independent of rapamycin-mediated mTOR pathway inactivation. Overall, our data suggest the existence of variant nucleosomes produced by the differential expression of the replication-dependent histone genes across retinal development. Also, the expression of a subset of replication-dependent histone isotypes in senescent neurons warrants re-examining these genes as "replication-dependent." Thus, our findings underscore the importance of understanding the transcriptional regulation of replication-dependent histone genes in the maintenance and functioning of neurons. PMID:25486194

  14. Subretinal Injection of Gene Therapy Vectors and Stem Cells in the Perinatal Mouse Eye

    PubMed Central

    Wert, Katherine J.; Skeie, Jessica M.; Davis, Richard J.; Tsang, Stephen H.; Mahajan, Vinit B.

    2012-01-01

    The loss of sight affects approximately 3.4 million people in the United States and is expected to increase in the upcoming years.1 Recently, gene therapy and stem cell transplantations have become key therapeutic tools for treating blindness resulting from retinal degenerative diseases. Several forms of autologous transplantation for age-related macular degeneration (AMD), such as iris pigment epithelial cell transplantation, have generated encouraging results, and human clinical trials have begun for other forms of gene and stem cell therapies.2 These include RPE65 gene replacement therapy in patients with Leber's congenital amaurosis and an RPE cell transplantation using human embryonic stem (ES) cells in Stargardt's disease.3-4 Now that there are gene therapy vectors and stem cells available for treating patients with retinal diseases, it is important to verify these potential therapies in animal models before applying them in human studies. The mouse has become an important scientific model for testing the therapeutic efficacy of gene therapy vectors and stem cell transplantation in the eye.5-8 In this video article, we present a technique to inject gene therapy vectors or stem cells into the subretinal space of the mouse eye while minimizing damage to the surrounding tissue. PMID:23207897

  15. Gene therapy on demand: site specific regulation of gene therapy.

    PubMed

    Jazwa, Agnieszka; Florczyk, Urszula; Jozkowicz, Alicja; Dulak, Jozef

    2013-08-10

    Since 1990 when the first clinical gene therapy trial was conducted, much attention and considerable promise have been given to this form of treatment. Gene therapy has been used with success in patients suffering from severe combined immunodeficiency syndromes (X-SCID and ADA-deficiency), Leber's congenital amaurosis, hemophilia, β-thalassemia and adrenoleukodystrophy. Last year, the first therapeutic vector (Glybera) for treatment of lipoprotein lipase deficiency has been registered in the European Union. Nevertheless, there are still several numerous issues that need to be improved to make this technique more safe, effective and easily accessible for patients. Introduction of the therapeutic gene to the given cells should provide the level of expression which will restore the production of therapeutic protein to normal values or will provide therapeutic efficacy despite not fully physiological expression. However, in numerous diseases the expression of therapeutic genes has to be kept at certain level for some time, and then might be required to be switched off to be activated again when worsening of the symptoms may aggravate the risk of disease relapse. In such cases the promoters which are regulated by local conditions may be more required. In this article the special emphasis is to discuss the strategies of regulation of gene expression by endogenous stimuli. Particularly, the hypoxia- or miRNA-regulated vectors offer the possibilities of tight but, at the same time, condition-dependent and cell-specific expression. Such means have been already tested in certain pathophysiological conditions. This creates the chance for the translational approaches required for development of effective treatments of so far incurable diseases. PMID:23566848

  16. A novel start codon mutation of the MERTK gene in a patient with retinitis pigmentosa

    PubMed Central

    Jinda, Worapoj; Poungvarin, Naravat; Taylor, Todd D.; Suzuki, Yutaka; Thongnoppakhun, Wanna; Limwongse, Chanin; Lertrit, Patcharee; Suriyaphol, Prapat

    2016-01-01

    Purpose Retinitis pigmentosa (RP) is a clinically and genetically heterogeneous group of inherited retinal degenerations characterized by progressive loss of photoreceptor cells and RPE functions. More than 70 causative genes are known to be responsible for RP. This study aimed to identify the causative gene in a patient from a consanguineous family with childhood-onset severe retinal dystrophy. Methods To identify the defective gene, whole exome sequencing was performed. Candidate causative variants were selected and validated using Sanger sequencing. Segregation analysis of the causative gene was performed in additional family members. To verify that the mutation has an effect on protein synthesis, an expression vector containing the first ten amino acids of the mutant protein fused with the DsRed2 fluorescent protein was constructed and transfected into HEK293T cells. Expression of the fusion protein in the transfected cells was measured using fluorescence microscopy. Results By filtering against public variant databases, a novel homozygous missense mutation (c.3G>A) localized in the start codon of the MERTK gene was detected as a potentially pathogenic mutation for autosomal recessive RP. The c.3G>A mutation cosegregated with the disease phenotype in the family. No expression of the first ten amino acids of the MerTK mutant fused with the DsRed2 fluorescent protein was detected in HEK293T cells, indicating that the mutation affects the translation initiation site of the gene that may lead to loss of function of the MerTK signaling pathway. Conclusions We report a novel missense mutation (c.3G>A, p.0?) in the MERTK gene that causes severe vision impairment in a patient. Taken together with previous reports, our results expand the spectrum of MERTK mutations and extend our understanding of the role of the MerTK protein in the pathogenesis of retinitis pigmentosa. PMID:27122965

  17. Mutation analysis in 129 genes associated with other forms of retinal dystrophy in 157 families with retinitis pigmentosa based on exome sequencing

    PubMed Central

    Xu, Yan; Guan, Liping; Xiao, Xueshan; Zhang, Jianguo; Li, Shiqiang; Jiang, Hui; Jia, Xiaoyun; Yang, Jianhua; Guo, Xiangming; Yin, Ye; Wang, Jun

    2015-01-01

    Purpose Mutations in 60 known genes were previously identified by exome sequencing in 79 of 157 families with retinitis pigmentosa (RP). This study analyzed variants in 129 genes associated with other forms of hereditary retinal dystrophy in the same cohort. Methods Apart from the 73 genes previously analyzed, a further 129 genes responsible for other forms of hereditary retinal dystrophy were selected based on RetNet. Variants in the 129 genes determined by whole exome sequencing were selected and filtered by bioinformatics analysis. Candidate variants were confirmed by Sanger sequencing and validated by analysis of available family members and controls. Results A total of 90 candidate variants were present in the 129 genes. Sanger sequencing confirmed 83 of the 90 variants. Analysis of family members and controls excluded 76 of these 83 variants. The remaining seven variants were considered to be potential pathogenic mutations; these were c.899A>G, c.1814C>G, and c.2107C>T in BBS2; c.1073C>T and c.1669C>T in INPP5E; and c.3582C>G and c.5704–5C>G in CACNA1F. Six of these seven mutations were novel. The mutations were detected in five unrelated patients without a family history, including three patients with homozygous or compound heterozygous mutations in BBS2 and INPP5E, and two patients with hemizygous mutations in CACNA1F. None of the patients had mutations in the genes associated with autosome dominant retinal dystrophy. Conclusions Only a small portion of patients with RP, about 3% (5/157), had causative mutations in the 129 genes associated with other forms of hereditary retinal dystrophy. PMID:25999675

  18. Fine genetic mapping of a gene for autosomal recessive retinitis pigmentosa on chromosome 6p21

    SciTech Connect

    Shugart, Yin Y.; Banerjee, P.; Knowles, J.A.

    1995-08-01

    The inherited retinal degenerations known as retinitis pigmentosa (RP) can be caused by mutations at many different loci and can be inherited as an autosomal recessive, autosomal dominant, or X-linked recessive trait. Two forms of autosomal recessive (arRP) have been reported to cosegregate with mutations in the rhodopsin gene and the beta-subunit of rod phosphodiesterase on chromosome 4p. Genetic linkage has been reported on chromosomes 6p and 1q. In a large Dominican family, we reported an arRp gene near the region of the peripherin/RDS gene. Four recombinations were detected between the disease locus and an intragenic marker derived from peripherin/RDS. 26 refs., 2 figs., 1 tab.

  19. Heat shock protein expression as guidance for the therapeutic window of retinal laser therapy

    NASA Astrophysics Data System (ADS)

    Wang, Jenny; Huie, Philip; Dalal, Roopa; Lee, Seungjun; Tan, Gavin; Lee, Daeyoung; Lavinksy, Daniel; Palanker, Daniel

    2016-03-01

    Unlike conventional photocoagulation, non-damaging retinal laser therapy (NRT) limits laser-induced heating to stay below the retinal damage threshold and therefore requires careful dosimetry. Without the adverse effects associated with photocoagulation, NRT can be applied to critical areas of the retina and repeatedly to manage chronic disorders. Although the clinical benefits of NRT have been demonstrated, the mechanism of therapeutic effect and width of the therapeutic window below damage threshold are not well understood. Here, we measure activation of heat shock response via laser-induced hyperthermia as one indication of cellular response. A 577 nm laser is used with the Endpoint Management (EpM) user interface, a titration algorithm, to set experimental pulse energies relative to a barely visible titration lesion. Live/dead staining and histology show that the retinal damage threshold in rabbits is at 40% of titration energy on EpM scale. Heat shock protein 70 (HSP70) expression in the retinal pigment epithelium (RPE) was detected by whole-mount immunohistochemistry after different levels of laser treatment. We show HSP70 expression in the RPE beginning at 25% of titration energy indicating that there is a window for NRT between 25% and 40% with activation of the heat shock protein expression in response to hyperthermia. HSP70 expression is also seen at the perimeter of damaging lesions, as expected based on a computational model of laser heating. Expression area for each pulse energy setting varied between laser spots due to pigmentation changes, indicating the relatively narrow window of non-damaging activation and highlighting the importance of proper titration.

  20. Gene Therapy in the Cornea: 2005-present

    PubMed Central

    Mohan, Rajiv R.; Tovey, Jonathan C.K.; Sharma, Ajay; Tandon, Ashish

    2011-01-01

    Successful restoration of vision in human patients with gene therapy affirmed its promise to cure ocular diseases and disorders. The efficacy of gene therapy is contingent upon vector and mode of therapeutic DNA introduction into targeted cells/tissues. The cornea is an ideal tissue for gene therapy due to its ease of access and relative immune-privilege. Considerable progress has been made in the field of corneal gene therapy in last 5 years. Several new gene transfer vectors, techniques and approaches have evolved. Although corneal gene therapy is still in its early stages of development, the potential of gene-based interventions to treat corneal abnormalities have begun to surface. Identification of next generation viral and nanoparticle vectors, characterization of delivered gene levels, localization, and duration in the cornea, and significant success in controlling corneal disorders, particularly fibrosis and angiogenesis, in experimental animal disease models, with no major side effects have propelled gene therapy a step closer towards establishing gene-based therapies for corneal blindness. Recently, researchers have assessed the delivery of therapeutic genes for corneal diseases and disorders due to trauma, infections, chemical, mechanical, and surgical injury, and/or abnormal wound healing. This review provides an update on the developments in gene therapy for corneal diseases and discusses the barriers that hinder its utilization for delivering genes in the cornea. PMID:21967960

  1. Gene therapy for prostate cancer.

    PubMed

    Tangney, Mark; Ahmad, Sarfraz; Collins, Sara A; O'Sullivan, Gerald C

    2010-05-01

    Cancer remains a leading cause of morbidity and mortality. Despite advances in understanding, detection, and treatment, it accounts for almost one-fourth of all deaths per year in Western countries. Prostate cancer is currently the most commonly diagnosed noncutaneous cancer in men in Europe and the United States, accounting for 15% of all cancers in men. As life expectancy of individuals increases, it is expected that there will also be an increase in the incidence and mortality of prostate cancer. Prostate cancer may be inoperable at initial presentation, unresponsive to chemotherapy and radiotherapy, or recur following appropriate treatment. At the time of presentation, patients may already have metastases in their tissues. Preventing tumor recurrence requires systemic therapy; however, current modalities are limited by toxicity or lack of efficacy. For patients with such metastatic cancers, the development of alternative therapies is essential. Gene therapy is a realistic prospect for the treatment of prostate and other cancers, and involves the delivery of genetic information to the patient to facilitate the production of therapeutic proteins. Therapeutics can act directly (eg, by inducing tumor cells to produce cytotoxic agents) or indirectly by upregulating the immune system to efficiently target tumor cells or by destroying the tumor's vasculature. However, technological difficulties must be addressed before an efficient and safe gene medicine is achieved (primarily by developing a means of delivering genes to the target cells or tissue safely and efficiently). A wealth of research has been carried out over the past 20 years, involving various strategies for the treatment of prostate cancer at preclinical and clinical trial levels. The therapeutic efficacy observed with many of these approaches in patients indicates that these treatment modalities will serve as an important component of urological malignancy treatment in the clinic, either in isolation or

  2. Identical Mutation in a Novel Retinal Gene Causes Progressive Rod-Cone Degeneration (prcd) in Dogs and Retinitis Pigmentosa in Man

    PubMed Central

    Zangerl, Barbara; Goldstein, Orly; Philp, Alisdair R.; Lindauer, Sarah J.P.; Pearce-Kelling, Susan E.; Mullins, Robert F.; Graphodatsky, Alexander S.; Ripoll, Daniel; Felix, Jeanette S.; Stone, Edwin M.; Acland, Gregory M.; Aguirre, Gustavo D.

    2014-01-01

    Progressive rod-cone degeneration (prcd) is a late-onset, autosomal recessive photoreceptor degeneration of dogs, and a homolog for some forms of human retinitis pigmentosa (RP). Previously, the disease relevant interval was reduced to a 106 Kb region on CFA9, and a common phenotype-specific haplotype was identified in all affected dogs from several different breeds, and breed varieties. Screening of a canine retinal EST library identified partial cDNAs for novel candidate genes in the disease relevant interval. The complete cDNA of one of these, PRCD, was cloned in dog, human and mouse. The gene codes for a 54 amino acid (aa) protein in dog and human, and 53 aa protein in the mouse; the first 24 aa, coded for by exon 1, are highly conserved in 14 vertebrate species. A homozygous mutation (TGC → TAC) in the second codon shows complete concordance with the disorder in 18 different dog breeds/breed varieties tested. The same homozygous mutation was identified in a human patient from Bangladesh with autosomal recessive (ar) RP. Expression studies support the predominant expression of this gene in the retina, with equal expression in the retinal pigment epithelium (RPE), photoreceptors and ganglion cell layers. This study provides strong evidence that a mutation in the novel gene, PRCD, is the cause of autosomal recessive retinal degeneration in both dogs and man. PMID:16938425

  3. AAV-Mediated Clarin-1 Expression in the Mouse Retina: Implications for USH3A Gene Therapy

    PubMed Central

    Deng, Wen-Tao; Dyka, Frank M.; Min, Seok-Hong; Boye, Sanford L.; Chiodo, Vince A.; Abrahan, Carolina E.; Zhu, Ping; Li, Qiuhong; Strettoi, Enrica; Novelli, Elena; Nagel-Wolfrum, Kerstin; Wolfrum, Uwe; Smith, W. Clay; Hauswirth, William W.

    2016-01-01

    Usher syndrome type III (USH3A) is an autosomal recessive disorder caused by mutations in clarin-1 (CLRN1) gene, leading to progressive retinal degeneration and sensorineural deafness. Efforts to develop therapies for preventing photoreceptor cell loss are hampered by the lack of a retinal phenotype in the existing USH3 mouse models and by conflicting reports regarding the endogenous retinal localization of clarin-1, a transmembrane protein of unknown function. In this study, we used an AAV-based approach to express CLRN1 in the mouse retina in order to determine the pattern of its subcellular localization in different cell types. We found that all major classes of retinal cells express AAV-delivered CLRN1 driven by the ubiquitous, constitutive small chicken β-actin promoter, which has important implications for the design of future USH3 gene therapy studies. Within photoreceptor cells, AAV-expressed CLRN1 is mainly localized at the inner segment region and outer plexiform layer, similar to the endogenous expression of other usher proteins. Subretinal delivery using a full strength viral titer led to significant loss of retinal function as evidenced by ERG analysis, suggesting that there is a critical limit for CLRN1 expression in photoreceptor cells. Taken together, these results suggest that CLRN1 expression is potentially supported by a variety of retinal cells, and the right combination of AAV vector dose, promoter, and delivery method needs to be selected to develop safe therapies for USH3 disorder. PMID:26881841

  4. Investor Outlook: Significance of the Positive LCA2 Gene Therapy Phase III Results.

    PubMed

    Schimmer, Joshua; Breazzano, Steven

    2015-12-01

    Spark Therapeutics recently reported positive phase III results for SPK-RPE65 targeting the treatment of visual impairment caused by RPE65 gene mutations (often referred to as Leber congenital amaurosis type 2, or LCA2, but may include other retinal disorders), marking an important inflection point for the field of gene therapy. The results highlight the ability to successfully design and execute a randomized trial of a gene therapy and also reinforce the potentially predictive nature of early preclinical and clinical data. The results are expected to pave the way for the first approved gene therapy product in the United States and should sustain investor interest and confidence in gene therapy for many approaches, including retina targeting and beyond. PMID:26684444

  5. Gene therapy for bone healing

    PubMed Central

    Evans, Christopher H.

    2015-01-01

    Clinical problems in bone healing include large segmental defects, nonunion and delayed union of fractures, and spinal fusions. Gene-transfer technologies have the potential to aid healing by permitting the local delivery and sustained expression of osteogenic gene products within osseous lesions. Key questions for such an approach include the choice of transgene, vector and gene-transfer strategy. Most experimental data have been obtained using cDNAs encoding osteogenic growth factors such as bone morphogenetic protein-2 (BMP-2), BMP-4 and BMP-7, in conjunction with both nonviral and viral vectors using in vivo and ex vivo delivery strategies. Proof of principle has been convincingly demonstrated in small-animal models. Relatively few studies have used large animals, but the results so far are encouraging. Once a reliable method has been developed, it will be necessary to perform detailed pharmacological and toxicological studies, as well as satisfy other demands of the regulatory bodies, before human clinical trials can be initiated. Such studies are very expensive and often protracted. Thus, progress in developing a clinically useful gene therapy for bone healing is determined not only by scientific considerations, but also by financial constraints and the ambient regulatory environment. PMID:20569532

  6. In Vivo CRISPR/Cas9 Gene Editing Corrects Retinal Dystrophy in the S334ter-3 Rat Model of Autosomal Dominant Retinitis Pigmentosa.

    PubMed

    Bakondi, Benjamin; Lv, Wenjian; Lu, Bin; Jones, Melissa K; Tsai, Yuchun; Kim, Kevin J; Levy, Rachelle; Akhtar, Aslam Abbasi; Breunig, Joshua J; Svendsen, Clive N; Wang, Shaomei

    2016-03-01

    Reliable genome editing via Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR)/Cas9 may provide a means to correct inherited diseases in patients. As proof of principle, we show that CRISPR/Cas9 can be used in vivo to selectively ablate the rhodopsin gene carrying the dominant S334ter mutation (Rho(S334)) in rats that model severe autosomal dominant retinitis pigmentosa. A single subretinal injection of guide RNA/Cas9 plasmid in combination with electroporation generated allele-specific disruption of Rho(S334), which prevented retinal degeneration and improved visual function. PMID:26666451

  7. In Vivo CRISPR/Cas9 Gene Editing Corrects Retinal Dystrophy in the S334ter-3 Rat Model of Autosomal Dominant Retinitis Pigmentosa

    PubMed Central

    Bakondi, Benjamin; Lv, Wenjian; Lu, Bin; Jones, Melissa K; Tsai, Yuchun; Kim, Kevin J; Levy, Rachelle; Akhtar, Aslam Abbasi; Breunig, Joshua J; Svendsen, Clive N; Wang, Shaomei

    2016-01-01

    Reliable genome editing via Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR)/Cas9 may provide a means to correct inherited diseases in patients. As proof of principle, we show that CRISPR/Cas9 can be used in vivo to selectively ablate the rhodopsin gene carrying the dominant S334ter mutation (RhoS334) in rats that model severe autosomal dominant retinitis pigmentosa. A single subretinal injection of guide RNA/Cas9 plasmid in combination with electroporation generated allele-specific disruption of RhoS334, which prevented retinal degeneration and improved visual function. PMID:26666451

  8. Progress of mesenchymal stem cell therapy for neural and retinal diseases

    PubMed Central

    Ng, Tsz Kin; Fortino, Veronica R; Pelaez, Daniel; Cheung, Herman S

    2014-01-01

    Complex circuitry and limited regenerative power make central nervous system (CNS) disorders the most challenging and difficult for functional repair. With elusive disease mechanisms, traditional surgical and medical interventions merely slow down the progression of the neurodegenerative diseases. However, the number of neurons still diminishes in many patients. Recently, stem cell therapy has been proposed as a viable option. Mesenchymal stem cells (MSCs), a widely-studied human adult stem cell population, have been discovered for more than 20 years. MSCs have been found all over the body and can be conveniently obtained from different accessible tissues: bone marrow, blood, and adipose and dental tissue. MSCs have high proliferative and differentiation abilities, providing an inexhaustible source of neurons and glia for cell replacement therapy. Moreover, MSCs also show neuroprotective effects without any genetic modification or reprogramming. In addition, the extraordinary immunomodulatory properties of MSCs enable autologous and heterologous transplantation. These qualities heighten the clinical applicability of MSCs when dealing with the pathologies of CNS disorders. Here, we summarize the latest progress of MSC experimental research as well as human clinical trials for neural and retinal diseases. This review article will focus on multiple sclerosis, spinal cord injury, autism, glaucoma, retinitis pigmentosa and age-related macular degeneration. PMID:24772238

  9. Interplay of retinal determination gene network with TGF-β signaling pathway in epithelial-mesenchymal transition.

    PubMed

    Liu, Yu; Kong, Deguang; Wu, Hua; Yuan, Xun; Xu, Hanxiao; Zhang, Cuntai; Wu, Gaosong; Wu, Kongming

    2015-01-01

    As a fundamental event in the generation of tissues and organs during embryogenesis, the epithelial-mesenchymal transition (EMT) has also been implicated in cancer progression by its ability to alter the plasticity of epithelial cells to acquire invasive properties. Evidence is mounting that ectopic activation of transforming growth factors β (TGF-β)/bone morphogenetic protein (BMP) superfamily members to enhance tumorigenesis and metastasis. In this respect, the Retinal Determination Gene Network (RDGN), which was identified to govern the normal initiation of the morphogenetic furrow in Drosophila, has now been found to be de-regulated in various types of cancers, and the key members of this network, DACH, SIX, and EYA, have emerged as novel co-regulators of TGF- signaling during EMT. Understanding the molecular mechanism by which RDGN regulates TGF-β/BMP signaling to influence EMT may lead to novel strategies for targeted therapies. PMID:27358880

  10. Interplay of retinal determination gene network with TGF-β signaling pathway in epithelial-mesenchymal transition

    PubMed Central

    Liu, Yu; Kong, Deguang; Wu, Hua; Yuan, Xun; Xu, Hanxiao; Zhang, Cuntai; Wu, Gaosong

    2015-01-01

    As a fundamental event in the generation of tissues and organs during embryogenesis, the epithelial-mesenchymal transition (EMT) has also been implicated in cancer progression by its ability to alter the plasticity of epithelial cells to acquire invasive properties. Evidence is mounting that ectopic activation of transforming growth factors β (TGF-β)/bone morphogenetic protein (BMP) superfamily members to enhance tumorigenesis and metastasis. In this respect, the Retinal Determination Gene Network (RDGN), which was identified to govern the normal initiation of the morphogenetic furrow in Drosophila, has now been found to be de-regulated in various types of cancers, and the key members of this network, DACH, SIX, and EYA, have emerged as novel co-regulators of TGF- signaling during EMT. Understanding the molecular mechanism by which RDGN regulates TGF-β/BMP signaling to influence EMT may lead to novel strategies for targeted therapies. PMID:27358880

  11. Form-Deprivation Myopia in Chick Induces Limited Changes in Retinal Gene Expression

    PubMed Central

    McGlinn, Alice M.; Baldwin, Donald A.; Tobias, John W.; Budak, Murat T.; Khurana, Tejvir S.; Stone, Richard A.

    2007-01-01

    Purpose Evidence has implicated the retina as a principal controller of refractive development. In the present study, the retinal transcriptome was analyzed to identify alterations in gene expression and potential signaling pathways involved in form-deprivation myopia of the chick. Methods One-week-old white Leghorn chicks wore a unilateral image-degrading goggle for 6 hours or 3 days (n = 6 at each time). Total RNA from the retina/(retinal pigment epithelium) was used for expression profiling with chicken gene microarrays (Chicken GeneChips; Affymetrix, Santa Clara, CA). To identify gene expression level differences between goggled and contralateral nongoggled eyes, normalized microarray signal intensities were analyzed by the significance analysis of microarrays (SAM) approach. Differentially expressed genes were validated by real-time quantitative reverse transcription–polymerase chain reaction (qPCR) in independent biological replicates. Results Small changes were detected in differentially expressed genes in form-deprived eyes. In chickens that had 6 hours of goggle wear, downregulation of bone morphogenetic protein 2 and connective tissue growth factor was validated. In those with 3 days of goggle wear, downregulation of bone morphogenetic protein 2, vasoactive intestinal peptide, preopro-urotensin II–related peptide and mitogen-activated protein kinase phosphatase 2 was validated, and upregulation of endothelin receptor type B and interleukin-18 was validated. Conclusions Form-deprivation myopia, in its early stages, is associated with only minimal changes in retinal gene expression at the level of the transcriptome. While the list of validated genes is short, each merits further study for potential involvement in the signaling cascade mediating myopia development. PMID:17652709

  12. Targeting Herpetic Keratitis by Gene Therapy

    PubMed Central

    Elbadawy, Hossein Mostafa; Gailledrat, Marine; Desseaux, Carole; Ponzin, Diego; Ferrari, Stefano

    2012-01-01

    Ocular gene therapy is rapidly becoming a reality. By November 2012, approximately 28 clinical trials were approved to assess novel gene therapy agents. Viral infections such as herpetic keratitis caused by herpes simplex virus 1 (HSV-1) can cause serious complications that may lead to blindness. Recurrence of the disease is likely and cornea transplantation, therefore, might not be the ideal therapeutic solution. This paper will focus on the current situation of ocular gene therapy research against herpetic keratitis, including the use of viral and nonviral vectors, routes of delivery of therapeutic genes, new techniques, and key research strategies. Whereas the correction of inherited diseases was the initial goal of the field of gene therapy, here we discuss transgene expression, gene replacement, silencing, or clipping. Gene therapy of herpetic keratitis previously reported in the literature is screened emphasizing candidate gene therapy targets. Commonly adopted strategies are discussed to assess the relative advantages of the protective therapy using antiviral drugs and the common gene therapy against long-term HSV-1 ocular infections signs, inflammation and neovascularization. Successful gene therapy can provide innovative physiological and pharmaceutical solutions against herpetic keratitis. PMID:23326647

  13. Altered aldose reductase gene regulation in cultured human retinal pigment epithelial cells.

    PubMed Central

    Henry, D N; Del Monte, M; Greene, D A; Killen, P D

    1993-01-01

    Aldose reductase (AR2), a putative "hypertonicity stress protein" whose gene is induced by hyperosmolarity, protects renal medullary cells against the interstitial hyperosmolarity of antidiuresis by catalyzing the synthesis of millimolar concentrations of intracellular sorbitol from glucose. Although AR2 gene induction has been noted in a variety of renal and nonrenal cells subjected to hypertonic stress in vitro, the functional significance of AR2 gene expression in cells not normally exposed to a hyperosmolar milieu is not fully understood. The physiological impact of basal AR2 expression in such cells may be limited to hyperglycemic states in which AR2 promotes pathological polyol accumulation, a mechanism invoked in the pathogenesis of diabetic complications. Since AR2 overexpression in the retinal pigment epithelium has been associated with diabetic retinopathy, the regulation of AR2 gene expression and associated changes in sorbitol and myo-inositol were studied in human retinal pigment epithelial cells in culture. The relative abundance of aldehyde reductase (AR1) and AR2 mRNA was quantitated by filter hybridization of RNA from several human retinal pigment epithelial cell lines exposed to hyperglycemic and hyperosmolar conditions in vitro. AR2 but not AR1 mRNA was significantly increased some 11- to 18-fold by hyperosmolarity in several retinal pigment epithelial cell lines. A single cell line with a 15-fold higher basal level of AR2 mRNA than other cell lines tested demonstrated no significant increase in AR2 mRNA in response to hypertonic stress. This cell line demonstrated accelerated and exaggerated production of sorbitol and depletion of myo-inositol upon exposure to 20 mM glucose. Therefore, abnormal AR2 expression may enhance the sensitivity of cells to the biochemical consequences of hyperglycemia potentiating the development of diabetic complications. Images PMID:8349800

  14. Immunomodulatory gene therapy in lysosomal storage disorders

    PubMed Central

    Koeberl, D.D.; Kishnani, P.S.

    2010-01-01

    Significant advances in therapy for lysosomal storage disorders have occurred with an accelerating pace over the past decade. Although enzyme replacement therapy has improved the outcome of lysosomal storage disorders, antibody responses have occurred and sometimes prevented efficacy, especially in cross-reacting immune material negative patients with Pompe disease. Preclinical gene therapy experiments have revealed the relevance of immune responses to long-term efficacy. The choice of regulatory cassette played a critical role in evading humoral and cellular immune responses to gene therapy in knockout mouse models, at least in adult animals. Liver-specific regulatory cassettes prevented antibody formation and enhanced the efficacy of gene therapy. Regulatory T cells prevented transgene directed immune responses, as shown by adoptive transfer of antigen-specific immune tolerance to enzyme therapy. Immunomodulatory gene therapy with a very low vector dose could enhance the efficacy of enzyme therapy in Pompe disease and other lysosomal storage disorders. PMID:19807648

  15. Immunomodulatory gene therapy in lysosomal storage disorders.

    PubMed

    Koeberl, Dwight D; Kishnani, Priya S

    2009-12-01

    Significant advances in therapy for lysosomal storage disorders have occurred with an accelerating pace over the past decade. Although enzyme replacement therapy has improved the outcome of lysosomal storage disorders, antibody responses have occurred and sometimes prevented efficacy, especially in cross-reacting immune material negative patients with Pompe disease. Preclinical gene therapy experiments have revealed the relevance of immune responses to long-term efficacy. The choice of regulatory cassette played a critical role in evading humoral and cellular immune responses to gene therapy in knockout mouse models, at least in adult animals. Liver-specific regulatory cassettes prevented antibody formation and enhanced the efficacy of gene therapy. Regulatory T cells prevented transgene directed immune responses, as shown by adoptive transfer of antigen-specific immune tolerance to enzyme therapy. Immunomodulatory gene therapy with a very low vector dose could enhance the efficacy of enzyme therapy in Pompe disease and other lysosomal storage disorders. PMID:19807648

  16. Experimental endostatin-GFP gene transfection into human retinal vascular endothelial cells using ultrasound-targeted cationic microbubble destruction

    PubMed Central

    Xu, Yan; Xie, Zongyuan; Zhou, Yu; Zhou, Xiyuan; Li, Pan; Wang, Zhigang

    2015-01-01

    Purpose The purpose of this study was to investigate whether ultrasound-targeted cationic microbubble destruction could effectively deliver endostatin-green fluorescent protein (ES-GFP) plasmids to human retinal vascular endothelial cells (HRECs). Methods Cationic microbubbles (CMBs) were prepared and then compared with neutral microbubbles (NMBs) and liposomes. First, the two types of microbubbles were characterized in terms of size and zeta potential. The cell viability of the HRECs was measured using the 3-(4,5-dimthylthiazol-2-yl)-2,5 diphenyl-tetrazolium bromide (MTT) assay. The transcription and expression of endostatin, VEGF, Bcl-2, and Bcl-xl were measured via quantitative real-time PCR (qPCR) and western blotting, respectively. Results CMBs differed significantly from NMBs in terms of the zeta potential, but no differences in size were detected. Following ultrasound-targeted microbubble destruction (UTMD)-mediated gene therapy, the transcription and expression of endostatin were highest in the CMB group (p<0.05), while the transcription and expression of VEGF, Bcl-2, and Bcl-xl were lowest compared with the other groups. Moreover, the inhibition of HREC growth was enhanced following treatment with CMBs compared with NMBs or liposomes in vitro (p<0.01). Conclusions This study demonstrated that ultrasound-mediated cationic microbubbles could enhance the transfection efficiency of ES-GFP, which had obvious impacts on the inhibition of the growth process of HRECs in vitro. These results suggest that the combination of UTMD and ES-GFP compounds might be a useful tool for gene therapy targeting retinal neovascularization. PMID:26321867

  17. Cardiac gene therapy: are we there yet?

    PubMed

    Matkar, P N; Leong-Poi, H; Singh, K K

    2016-08-01

    The incidence of cardiovascular disease (CVD) is increasing throughout the world and is associated with elevated morbidity and mortality. Gene therapy to treat cardiac dysfunction is gaining importance because of the limited therapeutic benefit offered by pharmacotherapies. The growing knowledge of the complex signaling pathways and the development of sophisticated vectors and delivery systems, are facilitating identification and targeting of specific molecular candidates involved in initiation and progression of CVDs. Several preclinical and clinical studies have shown the therapeutic efficiency of gene therapy in different disease models and patients. Hence, gene therapy might plausibly become an unconventional treatment modality for CVD patients. In this review, we summarize the gene delivery carriers, modes of delivery, recent preclinical/clinical studies and potential therapeutic targets. We also briefly discuss the existing limitations of gene therapy, technical challenges surrounding gene carriers and delivery systems, and some approaches to overcome these limitations for bringing CVD gene therapy one step closer to reality. PMID:27128687

  18. Gene therapy for ocular diseases meditated by ultrasound and microbubbles (Review)

    PubMed Central

    WAN, CAIFENG; LI, FENGHUA; LI, HONGLI

    2015-01-01

    The eye is an ideal target organ for gene therapy as it is easily accessible and immune-privileged. With the increasing insight into the underlying molecular mechanisms of ocular diseases, gene therapy has been proposed as an effective approach. Successful gene therapy depends on efficient gene transfer to targeted cells to prove stable and prolonged gene expression with minimal toxicity. At present, the main hindrance regarding the clinical application of gene therapy is not the lack of an ideal gene, but rather the lack of a safe and efficient method to selectively deliver genes to target cells and tissues. Ultrasound-targeted microbubble destruction (UTMD), with the advantages of high safety, repetitive applicability and tissue targeting, has become a potential strategy for gene- and drug delivery. When gene-loaded microbubbles are injected, UTMD is able to enhance the transport of the gene to the targeted cells. High-amplitude oscillations of microbubbles act as cavitation nuclei which can effectively focus ultrasound energy, produce oscillations and disruptions that increase the permeability of the cell membrane and create transient pores in the cell membrane. Thereby, the efficiency of gene therapy can be significantly improved. The UTMD-mediated gene delivery system has been widely used in pre-clinical studies to enhance gene expression in a site-specific manner in a variety of organs. With reasonable application, the effects of sonoporation can be spatially and temporally controlled to improve localized tissue deposition of gene complexes for ocular gene therapy applications. In addition, appropriately powered, focused ultrasound combined with microbubbles can induce a reversible disruption of the blood-retinal barrier with no significant side effects. The present review discusses the current status of gene therapy of ocular diseases as well as studies on gene therapy of ocular diseases meditated by UTMD. PMID:26151686

  19. AAV-Mediated Gene Therapy for Choroideremia: Preclinical Studies in Personalized Models

    PubMed Central

    Vasireddy, Vidyullatha; Kohnke, Monika; Black, Aaron D.; Alexandrov, Krill; Zhou, Shangzhen; Maguire, Albert M.; Chung, Daniel C.; Mac, Helen; Sullivan, Lisa; Gadue, Paul; Bennicelli, Jeannette L.; French, Deborah L.; Bennett, Jean

    2013-01-01

    Choroideremia (CHM) is an X- linked retinal degeneration that is symptomatic in the 1st or 2nd decade of life causing nyctalopia and loss of peripheral vision. The disease progresses through mid-life, when most patients become blind. CHM is a favorable target for gene augmentation therapy, as the disease is due to loss of function of a protein necessary for retinal cell health, Rab Escort Protein 1 (REP1).The CHM cDNA can be packaged in recombinant adeno-associated virus (rAAV), which has an established track record in human gene therapy studies, and, in addition, there are sensitive and quantitative assays to document REP1 activity. An animal model that accurately reflects the human condition is not available. In this study, we tested the ability to restore REP1 function in personalized in vitro models of CHM: lymphoblasts and induced pluripotent stems cells (iPSCs) from human patients. The initial step of evaluating safety of the treatment was carried out by evaluating for acute retinal histopathologic effects in normal-sighted mice and no obvious toxicity was identified. Delivery of the CHM cDNA to affected cells restores REP1 enzymatic activity and also restores proper protein trafficking. The gene transfer is efficient and the preliminary safety data are encouraging. These studies pave the way for a human clinical trial of gene therapy for CHM. PMID:23667438

  20. Gene therapy in monogenic congenital myopathies.

    PubMed

    Guan, Xuan; Goddard, Melissa A; Mack, David L; Childers, Martin K

    2016-04-15

    Current treatment options for patients with monogenetic congenital myopathies (MCM) ameliorate the symptoms of the disorder without resolving the underlying cause. However, gene therapies are being developed where the mutated or deficient gene target is replaced. Preclinical findings in animal models appear promising, as illustrated by gene replacement for X-linked myotubular myopathy (XLMTM) in canine and murine models. Prospective applications and approaches to gene replacement therapy, using these disorders as examples, are discussed in this review. PMID:26454198

  1. Identification of a rhodopsin gene mutation in a large family with autosomal dominant retinitis pigmentosa.

    PubMed

    Yu, Xinping; Shi, Wei; Cheng, Lulu; Wang, Yanfang; Chen, Ding; Hu, Xuting; Xu, Jinling; Xu, Limin; Wu, Yaming; Qu, Jia; Gu, Feng

    2016-01-01

    Retinitis pigmentosa (RP) is a genetically highly heterogeneous retinal disease and one of the leading causes of blindness in the world. Next-generation sequencing technology has enormous potential for determining the genetic etiology of RP. We sought to identify the underlying genetic defect in a 35-year-old male from an autosomal-dominant RP family with 14 affected individuals. By capturing next-generation sequencing (CNGS) of 144 genes associated with retinal diseases, we identified eight novel DNA variants; however, none of them cosegregated for all the members of the family. Further analysis of the CNGS data led to identification of a recurrent missense mutation (c.403C > T, p.R135W) in the rhodopsin (RHO) gene, which cosegregated with all affected individuals in the family and was not observed in any of the unaffected family members. The p.R135W mutation has a reference single nucleotide polymorphism (SNP) ID (rs104893775), and it appears to be responsible for the disease in this large family. This study highlights the importance of examining NGS data with reference SNP IDs. Thus, our study is important for data analysis of NGS-based clinical genetic diagnoses. PMID:26794436

  2. Identification of a rhodopsin gene mutation in a large family with autosomal dominant retinitis pigmentosa

    PubMed Central

    Yu, Xinping; Shi, Wei; Cheng, Lulu; Wang, Yanfang; Chen, Ding; Hu, Xuting; Xu, Jinling; Xu, Limin; Wu, Yaming; Qu, Jia; Gu, Feng

    2016-01-01

    Retinitis pigmentosa (RP) is a genetically highly heterogeneous retinal disease and one of the leading causes of blindness in the world. Next-generation sequencing technology has enormous potential for determining the genetic etiology of RP. We sought to identify the underlying genetic defect in a 35-year-old male from an autosomal-dominant RP family with 14 affected individuals. By capturing next-generation sequencing (CNGS) of 144 genes associated with retinal diseases, we identified eight novel DNA variants; however, none of them cosegregated for all the members of the family. Further analysis of the CNGS data led to identification of a recurrent missense mutation (c.403C > T, p.R135W) in the rhodopsin (RHO) gene, which cosegregated with all affected individuals in the family and was not observed in any of the unaffected family members. The p.R135W mutation has a reference single nucleotide polymorphism (SNP) ID (rs104893775), and it appears to be responsible for the disease in this large family. This study highlights the importance of examining NGS data with reference SNP IDs. Thus, our study is important for data analysis of NGS-based clinical genetic diagnoses. PMID:26794436

  3. Renal-Retinal Ciliopathy Gene Sdccag8 Regulates DNA Damage Response Signaling

    PubMed Central

    Airik, Rannar; Slaats, Gisela G.; Guo, Zhi; Weiss, Anna-Carina; Khan, Naheed; Ghosh, Amiya; Hurd, Toby W.; Bekker-Jensen, Simon; Schrøder, Jacob M.; Elledge, Steve J.; Andersen, Jens S.; Kispert, Andreas; Castelli, Maddalena; Boletta, Alessandra; Giles, Rachel H.

    2014-01-01

    Nephronophthisis-related ciliopathies (NPHP-RCs) are developmental and degenerative kidney diseases that are frequently associated with extrarenal pathologies such as retinal degeneration, obesity, and intellectual disability. We recently identified mutations in a gene encoding the centrosomal protein SDCCAG8 as causing NPHP type 10 in humans. To study the role of Sdccag8 in disease pathogenesis, we generated a Sdccag8 gene-trap mouse line. Homozygous Sdccag8gt/gt mice lacked the wild-type Sdccag8 transcript and protein, and recapitulated the human phenotypes of NPHP and retinal degeneration. These mice exhibited early onset retinal degeneration that was associated with rhodopsin mislocalization in the photoreceptors and reduced cone cell numbers, and led to progressive loss of vision. By contrast, renal histologic changes occurred later, and no global ciliary defects were observed in the kidneys. Instead, renal pathology was associated with elevated levels of DNA damage response signaling activity. Cell culture studies confirmed the aberrant activation of DNA damage response in Sdccag8gt/gt-derived cells, characterized by elevated levels of γH2AX and phosphorylated ATM and cell cycle profile abnormalities. Our analysis of Sdccag8gt/gt mice indicates that the pleiotropic phenotypes in these mice may arise through multiple tissue-specific disease mechanisms. PMID:24722439

  4. Tyrosine triple mutated AAV2-BDNF gene therapy in a rat model of transient IOP elevation

    PubMed Central

    Igarashi, Tsutomu; Kobayashi, Maika; Kameya, Shuhei; Fujimoto, Chiaki; Nakamoto, Kenji; Takahashi, Hisatomo; Igarashi, Toru; Miyake, Noriko; Iijima, Osamu; Hirai, Yukihiko; Shimada, Takashi; Okada, Takashi; Takahashi, Hiroshi

    2016-01-01

    Purpose We examined the neuroprotective effects of exogenous brain-derived neurotrophic factor (BDNF), which provides protection to retinal ganglion cells (RGCs) in rodents, in a model of transient intraocular pressure (IOP) elevation using a mutant (triple Y-F) self-complementary adeno-associated virus type 2 vector encoding BDNF (tm-scAAV2-BDNF). Methods The tm-scAAV2-BDNF or control vector encoding green fluorescent protein (GFP; tm-scAAV2-GFP) was intravitreally administered to rats, which were then divided into four groups: control, ischemia/reperfusion (I/R) injury only, I/R injury with tm-scAAV2-GFP, and tm-scAAV2-BDNF. I/R injury was then induced by transiently increasing IOP, after which the rats were euthanized to measure the inner retinal thickness and cell counts in the RGC layer. Results Intravitreous injection of tm-scAAV2-BDNF resulted in high levels of BDNF expression in the neural retina. Histological analysis showed that the inner retinal thickness and cell numbers in the RGC layer were preserved after transient IOP elevation in eyes treated with tm-scAAV2-BDNF but not in the other I/R groups. Significantly reduced glial fibrillary acidic protein (GFAP) immunostaining after I/R injury in the rats that received tm-scAAV2-BDNF indicated reduced retinal stress, and electroretinogram (ERG) analysis confirmed preservation of retinal function in the tm-scAAV2-BDNF group. Conclusions These results demonstrate the feasibility and effectiveness of neuroprotective gene therapy using tm-scAAV2-BDNF to protect the inner retina from transiently high intraocular pressure. An in vivo gene therapeutic approach to the clinical management of retinal diseases in conditions such as glaucoma, retinal artery occlusion, hypertensive retinopathy, and diabetic retinopathy thus appears feasible. PMID:27440998

  5. Gene therapy oversight: lessons for nanobiotechnology.

    PubMed

    Wolf, Susan M; Gupta, Rishi; Kohlhepp, Peter

    2009-01-01

    Oversight of human gene transfer research ("gene therapy") presents an important model with potential application to oversight of nanobiology research on human participants. Gene therapy oversight adds centralized federal review at the National Institutes of Health's Office of Biotechnology Activities and its Recombinant DNA Advisory Committee to standard oversight of human subjects research at the researcher's institution (by the Institutional Review Board and, for some research, the Institutional Biosafety Committee) and at the federal level by the Office for Human Research Protections. The Food and Drug Administration's Center for Biologics Evaluation and Research oversees human gene transfer research in parallel, including approval of protocols and regulation of products. This article traces the evolution of this dual oversight system; describes how the system is already addressing nanobiotechnology in gene transfer: evaluates gene therapy oversight based on public opinion, the literature, and preliminary expert elicitation; and offers lessons of the gene therapy oversight experience for oversight of nanobiotechnology. PMID:20122108

  6. Gene therapy of metachromatic leukodystrophy.

    PubMed

    Matzner, Ulrich; Gieselmann, Volkmar

    2005-01-01

    Metachromatic leukodystrophy (MLD) is a lysosomal storage disease that is caused by a deficiency of arylsulfatase A (ASA). The deficiency results in the intralysosomal accumulation of the acidic sphingolipid 3-O-sulfogalactosyl-ceramide (sulfatide). Patients suffer from progressive demyelination and die from multiple neurological deficits. Curative treatment is not available. ASA bears mannose 6-phosphate residues which function as recognition markers in endosome/lysosome-specific targeting pathways. The endocytic targeting route can be exploited to deliver exogenous ASA to the lysosomes of ASA-deficient cells. ASA knockout mice, which develop a disorder related to MLD, have therefore been treated by ex vivo and in vivo gene therapy. Following transplantation of bone marrow cells overexpressing ASA from a retroviral vector, donor-type cells secrete ASA, which is endocytosed by recipient cells. The enzyme transfer results in the metabolic cross-correction of recipient cells and the improvement of biochemical, histological and clinical parameters. For the transfer of the ASA cDNA to non-dividing cells, adenovirus, adeno-associated virus and lentivirus vectors have been constructed. Such vectors might be particularly advantageous for direct ASA gene delivery to the brain, which is the main site of disease in MLD. PMID:15709909

  7. Gene therapy for primary immunodeficiencies.

    PubMed

    Fischer, A; Hacein-Bey Abina, S; Touzot, F; Cavazzana, M

    2015-12-01

    Gene therapy has effectively entered Medicine via the field of primary immunodeficiencies (PID). Because hematopoietic stem cells are accessible and because it was understood that genetic correction of lymphocyte progenitor cells carrying a genetic defect impairing differentiation, could result in the production of long-lived T lymphocytes, it was reasoned that ex vivo gene transfer in hematopoietic cells could lead to disease phenotype correction. Retroviral vectors were designed to ex vivo transduce such cells. This has indeed been shown to lead to sustained correction of the T cell immunodeficiency associated with two forms of severe combined immunodeficiencies (SCID) for now more than ten years. Occurrence in some patients of genotoxicity related to retroviral vectors integration close to and transactivation of oncogenes has led to the development of retroviral vectors devoid of its enhancer element. Results of recent trials performed for several forms of PID indeed suggest that their use is both safe and efficacious. It is thus anticipated that their application to the treatment of many more life threatening PID will be developed over the coming years. PMID:25708106

  8. Dog models for blinding inherited retinal dystrophies.

    PubMed

    Petersen-Jones, Simon M; Komáromy, András M

    2015-03-01

    Spontaneous canine models exist for several inherited retinal dystrophies. This review will summarize the models and indicate where they have been used in translational gene therapy trials. The RPE65 gene therapy trials to treat childhood blindness are a good example of how studies in dogs have contributed to therapy development. Outcomes in human clinical trials are compared and contrasted with the result of the preclinical dog trials. PMID:25671556

  9. Dog Models for Blinding Inherited Retinal Dystrophies

    PubMed Central

    Komáromy, András M.

    2015-01-01

    Abstract Spontaneous canine models exist for several inherited retinal dystrophies. This review will summarize the models and indicate where they have been used in translational gene therapy trials. The RPE65 gene therapy trials to treat childhood blindness are a good example of how studies in dogs have contributed to therapy development. Outcomes in human clinical trials are compared and contrasted with the result of the preclinical dog trials. PMID:25671556

  10. Gene Therapy For Ischemic Heart Disease

    PubMed Central

    Lavu, Madhav; Gundewar, Susheel; Lefer, David J.

    2010-01-01

    Current pharmacologic therapy for ischemic heart disease suffers multiple limitations such as compliance issues and side effects of medications. Revascularization procedures often end with need for repeat procedures. Patients remain symptomatic despite maximal medical therapy. Gene therapy offers an attractive alternative to current pharmacologic therapies and may be beneficial in refractory disease. Gene therapy with isoforms of growth factors such as VEGF, FGF and HGF induces angiogenesis, decreases apoptosis and leads to protection in the ischemic heart. Stem cell therapy augmented with gene therapy used for myogenesis has proven to be beneficial in numerous animal models of myocardial ischemia. Gene therapy coding for antioxidants, eNOS, HSP, mitogen-activated protein kinase and numerous other anti apoptotic proteins have demonstrated significant cardioprotection in animal models. Clinical trials have demonstrated safety in humans apart from symptomatic and objective improvements in cardiac function. Current research efforts are aimed at refining various gene transfection techniques and regulation of gene expression in vivo in the heart and circulation to improve clinical outcomes in patients that suffer from ischemic heart disease. In this review article we will attempt to summarize the current state of both preclinical and clinical studies of gene therapy to combat myocardial ischemic disease. PMID:20600100

  11. Gene expression changes in the retina following subretinal injection of human neural progenitor cells into a rodent model for retinal degeneration

    PubMed Central

    Jones, Melissa K.; Lu, Bin; Saghizadeh, Mehrnoosh

    2016-01-01

    Purpose Retinal degenerative diseases (RDDs) affect millions of people and are the leading cause of vision loss. Although treatment options for RDDs are limited, stem and progenitor cell–based therapies have great potential to halt or slow the progression of vision loss. Our previous studies have shown that a single subretinal injection of human forebrain derived neural progenitor cells (hNPCs) into the Royal College of Surgeons (RCS) retinal degenerate rat offers long-term preservation of photoreceptors and visual function. Furthermore, neural progenitor cells are currently in clinical trials for treating age-related macular degeneration; however, the molecular mechanisms of stem cell–based therapies are largely unknown. This is the first study to analyze gene expression changes in the retina of RCS rats following subretinal injection of hNPCs using high-throughput sequencing. Methods RNA-seq data of retinas from RCS rats injected with hNPCs (RCShNPCs) were compared to sham surgery in RCS (RCSsham) and wild-type Long Evans (LEsham) rats. Differential gene expression patterns were determined with in silico analysis and confirmed with qRT-PCR. Function, biologic, cellular component, and pathway analyses were performed on differentially expressed genes and investigated with immunofluorescent staining experiments. Results Analysis of the gene expression data sets identified 1,215 genes that were differentially expressed between RCSsham and LEsham samples. Additionally, 283 genes were differentially expressed between the RCShNPCs and RCSsham samples. Comparison of these two gene sets identified 68 genes with inverse expression (termed rescue genes), including Pdc, Rp1, and Cdc42ep5. Functional, biologic, and cellular component analyses indicate that the immune response is enhanced in RCSsham. Pathway analysis of the differential expression gene sets identified three affected pathways in RCShNPCs, which all play roles in phagocytosis signaling. Immunofluorescent

  12. Gene therapy for high-grade glioma

    PubMed Central

    Natsume, Atsushi

    2008-01-01

    The treatment of high-grade gliomas remains difficult despite recent advances in surgery, radiotherapy and chemotherapy. True advances may emerge from the increasing understanding in molecular biology and discovery of novel mechanisms for the delivery of tumoricidal agents. In an attempt to overcome this formidable neoplasm, molecular approaches using gene therapy have been investigated clinically since 1992. The clinical trials have mainly been classified into three approaches: suicide gene therapy, immune gene therapy and oncolytic viral therapy. In this article, we review these approaches, which have been studied in previous and ongoing clinical trials. PMID:19262115

  13. [Gene therapy with cytokines against cervical cancer].

    PubMed

    Bermúdez-Morales, Victor Hugo; Peralta-Zaragoza, Oscar; Madrid-Marina, Vicente

    2005-01-01

    Gene therapy is an excellent alternative for treatment of many diseases. Capacity to manipulate the DNA has allowed direct the gene therapy to correct the function of an altered gene, to increase the expression of a gene and to favour the activation of the immune response. This way, it can intend the use of the DNA like medication able to control, to correct or to cure many diseases. Gene therapy against cancer has an enormous potential, and actually the use of the DNA has increased to control diverse cancer in animal models, with very encouraging results that have allowed its applications in experimental protocols in human. This work concentrates a review of the foundations of the gene therapy and its application on cervical cancer, from the point of view of the alterations of the immune system focused on the tumour micro-environment, and the use of the cytokines as immunomodulators. PMID:16983992

  14. Adenoviral Vectors for Hemophilia Gene Therapy

    PubMed Central

    Brunetti-Pierri, N; Ng, Philip

    2013-01-01

    Hemophilia is an inherited blood clotting disorder resulting from deficiency of blood coagulation factors. Current standard of care for hemophilia patients is frequent intravenous infusions of the missing coagulation factor. Gene therapy for hemophilia involves the introduction of a normal copy of the deficient coagulation factor gene thereby potentially offering a definitive cure for the bleeding disorder. A variety of approaches have been pursued for hemophilia gene therapy and this review article focuses on those that use adenoviral vectors. PMID:24883229

  15. Nanoparticle-mediated gene transfer specific to retinal pigment epithelial cells.

    PubMed

    Koirala, Adarsha; Makkia, Rasha S; Cooper, Mark J; Naash, Muna I

    2011-12-01

    Previously, we demonstrated that CK30PEG10k-compacted DNA nanoparticles (NPs) efficiently target photoreceptor cells and improve visual function in a retinitis pigmentosa model. Here, we test the ability of these NPs in driving transgene expression in the retinal pigment epithelium (RPE), using an RPE-specific reporter vector (VMD2-eGFP). NPs, uncompacted plasmid, or saline were subretinally delivered to adult BALB/c mice. NP-based expression was specific to RPE cells and caused no deleterious effects on retinal structure and function. eGFP expression levels in NP-injected eyes peaked at post-injection day 2 (PI-2), stabilized at levels ~3-fold higher than in naked DNA-injected eyes, and remained elevated at the latest time-point examined (PI-30). Unlike naked DNA, which only transfected cells at the site of injection, NPs were able to transfect cells throughout the RPE. Subretinal injections of rhodamine labeled NPs and naked DNA showed comparable initial uptake into RPE cells. However, at PI-7 and -30 days significantly more fluorescence was detected inside the RPE of NP-injected eyes compared to naked DNA, suggesting NPs are stable inside the cell which could possibly lead to higher and sustained expression. Overall, our results demonstrate that NPs can efficiently deliver genes to the RPE and hold great potential for the treatment of RPE-associated diseases. PMID:21885113

  16. Cationic Polyene Phospholipids as DNA Carriers for Ocular Gene Therapy

    PubMed Central

    Machado, Susana; Calado, Sofia; Bitoque, Diogo; Oliveira, Ana Vanessa; Øpstad, Christer L.; Zeeshan, Muhammad; Sliwka, Hans-Richard; Partali, Vassilia; Pungente, Michael D.; Silva, Gabriela A.

    2014-01-01

    Recent success in the treatment of congenital blindness demonstrates the potential of ocular gene therapy as a therapeutic approach. The eye is a good target due to its small size, minimal diffusion of therapeutic agent to the systemic circulation, and low immune and inflammatory responses. Currently, most approaches are based on viral vectors, but efforts continue towards the synthesis and evaluation of new nonviral carriers to improve nucleic acid delivery. Our objective is to evaluate the efficiency of novel cationic retinoic and carotenoic glycol phospholipids, designated C20-18, C20-20, and C30-20, to deliver DNA to human retinal pigmented epithelium (RPE) cells. Liposomes were produced by solvent evaporation of ethanolic mixtures of the polyene compounds and coformulated with 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE) or cholesterol (Chol). Addition of DNA to the liposomes formed lipoplexes, which were characterized for binding, size, biocompatibility, and transgene efficiency. Lipoplex formulations of suitable size and biocompatibility were assayed for DNA delivery, both qualitatively and quantitatively, using RPE cells and a GFP-encoding plasmid. The retinoic lipoplex formulation with DOPE revealed a transfection efficiency comparable to the known lipid references 3β-[N-(N′,N′-dimethylaminoethane)-carbamoyl]-cholesterol (DC-Chol) and 1,2-dioleoyl-sn-glycero-3-ethylphosphocholine (EPC) and GeneJuice. The results demonstrate that cationic polyene phospholipids have potential as DNA carriers for ocular gene therapy. PMID:25147812

  17. Achromatopsia as a Potential Candidate for Gene Therapy

    PubMed Central

    Pang, Ji-jing; Alexander, John; Lei, Bo; Deng, Wentao; Zhang, Keqing; Li, Qiuhong; Chang, Bo; Hauswirth, William W.

    2013-01-01

    Achromatopsia is an autosomal recessive retinal disease involving loss of cone function that afflicts approximately 1 in 30,000 individuals. Patients with achromatopsia usually have visual acuities lower than 20/200 because of the central vision loss, photophobia, complete color blindness and reduced cone-mediated electroretinographic (ERG) amplitudes. Mutations in three genes have been found to be the primary causes of achromatopsia, including CNGB3 (beta subunit of the cone cyclic nucleotide-gated cation channel), CNGA3 (alpha subunit of the cone cyclic nucleotide-gated cation channel), and GNAT2 (cone specific alpha subunit of transducin). Naturally occurring mouse models with mutations in Cnga3 (cpfl5 mice) and Gnat2 (cpfl3 mice) were discovered at The Jackson Laboratory. A natural occurring canine model with CNGB3 mutations has also been found. These animal models have many of the central phenotypic features of the corresponding human diseases. Using adeno-associated virus (AAV)-mediated gene therapy, we and others show that cone function can be restored in all three models. These data suggest that human achromatopsia may be a good candidate for corrective gene therapy. PMID:20238068

  18. Differential Proteomics and Functional Research following Gene Therapy in a Mouse Model of Leber Congenital Amaurosis

    PubMed Central

    Zheng, Qinxiang; Ren, Yueping; Tzekov, Radouil; Zhang, Yuanping; Chen, Bo; Hou, Jiangping; Zhao, Chunhui; Zhu, Jiali; Zhang, Ying; Dai, Xufeng; Ma, Shan; Li, Jia; Pang, Jijing; Qu, Jia; Li, Wensheng

    2012-01-01

    Leber congenital amaurosis (LCA) is one of the most severe forms of inherited retinal degeneration and can be caused by mutations in at least 15 different genes. To clarify the proteomic differences in LCA eyes, a cohort of retinal degeneration 12 (rd12) mice, an LCA2 model caused by a mutation in the RPE65 gene, were injected subretinally with an AAV vector (scAAV5-smCBA-hRPE65) in one eye, while the contralateral eye served as a control. Proteomics were compared between untreated rd12 and normal control retinas on P14 and P21, and among treated and untreated rd12 retinas and control retinas on P42. Gene therapy in rd12 mice restored retinal function in treated eyes, which was demonstrated by electroretinography (ERG). Proteomic analysis successfully identified 39 proteins expressed differently among the 3 groups. The expression of 3 proteins involved in regulation of apoptosis and neuroptotection (alpha A crystallin, heat shock protein 70 and peroxiredoxin 6) were investigated further. Immunofluorescence, Western blot and real-time PCR confirmed the quantitative changes in their expression. Furthermore, cell culture studies suggested that peroxiredoxin 6 could act in an antioxidant role in rd12 mice. Our findings support the feasibility of gene therapy in LCA2 patients and support a role for alpha A crystallin, heat shock protein 70 and peroxiredoxin 6 in the pathogenetic mechanisms involved in LCA2 disease process. PMID:22953002

  19. Differential proteomics and functional research following gene therapy in a mouse model of Leber congenital amaurosis.

    PubMed

    Zheng, Qinxiang; Ren, Yueping; Tzekov, Radouil; Zhang, Yuanping; Chen, Bo; Hou, Jiangping; Zhao, Chunhui; Zhu, Jiali; Zhang, Ying; Dai, Xufeng; Ma, Shan; Li, Jia; Pang, Jijing; Qu, Jia; Li, Wensheng

    2012-01-01

    Leber congenital amaurosis (LCA) is one of the most severe forms of inherited retinal degeneration and can be caused by mutations in at least 15 different genes. To clarify the proteomic differences in LCA eyes, a cohort of retinal degeneration 12 (rd12) mice, an LCA2 model caused by a mutation in the RPE65 gene, were injected subretinally with an AAV vector (scAAV5-smCBA-hRPE65) in one eye, while the contralateral eye served as a control. Proteomics were compared between untreated rd12 and normal control retinas on P14 and P21, and among treated and untreated rd12 retinas and control retinas on P42. Gene therapy in rd12 mice restored retinal function in treated eyes, which was demonstrated by electroretinography (ERG). Proteomic analysis successfully identified 39 proteins expressed differently among the 3 groups. The expression of 3 proteins involved in regulation of apoptosis and neuroptotection (alpha A crystallin, heat shock protein 70 and peroxiredoxin 6) were investigated further. Immunofluorescence, Western blot and real-time PCR confirmed the quantitative changes in their expression. Furthermore, cell culture studies suggested that peroxiredoxin 6 could act in an antioxidant role in rd12 mice. Our findings support the feasibility of gene therapy in LCA2 patients and support a role for alpha A crystallin, heat shock protein 70 and peroxiredoxin 6 in the pathogenetic mechanisms involved in LCA2 disease process. PMID:22953002

  20. Retinal Phenotypes in Patients Homozygous for the G1961E Mutation in the ABCA4 Gene

    PubMed Central

    Burke, Tomas R.; Fishman, Gerald A.; Zernant, Jana; Schubert, Carl; Tsang, Stephen H.; Smith, R. Theodore; Ayyagari, Radha; Koenekoop, Robert K.; Umfress, Allison; Ciccarelli, Maria Laura; Baldi, Alfonso; Iannaccone, Alessandro; Cremers, Frans P. M.; Klaver, Caroline C. W.; Allikmets, Rando

    2012-01-01

    Purpose. We evaluated the pathogenicity of the G1961E mutation in the ABCA4 gene, and present the range of retinal phenotypes associated with this mutation in homozygosity in a patient cohort with ABCA4-associated phenotypes. Methods. Patients were enrolled from the ABCA4 disease database at Columbia University or by inquiry from collaborating physicians. Only patients homozygous for the G1961E mutation were enrolled. The entire ABCA4 gene open reading frame, including all exons and flanking intronic sequences, was sequenced in all patients. Phenotype data were obtained from clinical history and examination, fundus photography, infrared imaging, fundus autofluorescence, fluorescein angiography, and spectral domain-optical coherence tomography. Additional functional data were obtained using the full-field electroretinogram, and static or kinetic perimetry. Results. We evaluated 12 patients homozygous for the G1961E mutation. All patients had evidence of retinal pathology consistent with the range of phenotypes observed in ABCA4 disease. The latest age of onset was recorded at 64 years, in a patient diagnosed initially with age-related macular degeneration (AMD). Of 6 patients in whom severe structural (with/without functional) fundus changes were detected, 5 had additional, heterozygous or homozygous, variants detected in the ABCA4 gene. Conclusions. Homozygous G1961E mutation in ABCA4 results in a range of retinal pathology. The phenotype usually is at the milder end of the disease spectrum, with severe phenotypes linked to the presence of additional ABCA4 variants. Our report also highlights that milder, late-onset Stargardt disease may be confused with AMD. PMID:22661473

  1. Screening of the arrestin gene in dogs afflicted with generalized progressive retinal atrophy

    PubMed Central

    Dekomien, Gabriele; Epplen, Jörg Thomas

    2002-01-01

    Background Intronic DNA sequences of the canine arrestin (SAG) gene was screened to identify potential disease causing mutations in dogs with generalized progressive retinal atrophy (gPRA). The intronic sequences flanking each of the 16 exons were obtained from clones of a canine genomic library. Results Using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and DNA sequence analyses we screened affected and unaffected dogs of 23 breeds with presumed autosomal recessively (ar) transmitted gPRA. In the coding region of the SAG gene 12 nucleotide exchanges were identified, 5 of which lead to amino acid substitutions (H14C; A111V; A113T; D259T; A379E). 7 other exonic substitutions represent silent polymorphisms (C132C; Q199Q; H225H; V247V; P264P; T288T and L293L). 16 additional sequence variations were observed in intronic regions of different dog breeds. Conclusions In several breeds, these polymorphisms were found in homozygous state in unaffected and in heterozygous state in affected animals. Consequently these informative substitutions provide evidence to exclude mutations in the SAG gene as causing retinal degeneration in 14 of the 23 dog breeds with presumed ar transmitted gPRA. PMID:12123530

  2. Evaluation of the United States Public Health Service guidelines for discontinuation of anti-CMV therapy after immune recovery in patients with CMV retinitis

    PubMed Central

    Holbrook, Janet T.; Colvin, Ryan; Van Natta, Mark L.; Thorne, Jennifer E.; Bardsley, Mark; Jabs, Douglas A.

    2011-01-01

    Purpose To evaluate US Public Health Service (USPHS) guidelines for discontinuing anti-CMV therapy in patients with AIDS who have immune recovery and quiescent retinitis after initiating highly active anti-retroviral therapy (HAART). Design Cohort study of patients with CMV retinitis (Longitudinal Study of Ocular Complications of AIDS). Methods Participants had CMV retinitis and CD4+ T-cell counts of 50 cells/uL or fewer enrolled from 1998 to 2009 who demonstrated sustained immune recovery (two consecutive CD4+ T-cell counts of 100 cells/uL or more at least 6 months apart) and inactive retinitis. Participants were classified into 2 groups according to anti-CMV treatment after immune recover: (1) continued anti-CMV therapy and (2) discontinued therapy. We evaluated survival, visual acuity, and CMV retinitis activity; we employed propensity scores to adjust for confounding factors for these analyses. Results Of 152 participants reviewed, 71 demonstrated immune recovery; 37 of whom discontinued therapy and 34 who continued therapy. At immune recovery, participants continuing therapy tended to be older (44 vs 40 years, P=0.09), have bilateral retinitis (53% vs 32%, P=0.10), and have lower CD4+ T-cell counts (148 vs 207 cells/μL, P<0.001). There were no statistical differences in any of the clinical outcomes (death, retinitis progress, visual acuity or incidence of bilateral retinitis). Both groups lost visual acuity during follow-up, on average 1.2 letters per year (P<0.01). Conclusion Discontinuation of anti-CMV therapy after immune recovery did not increase the risk of poor outcomes. These results support the current guidelines for discontinuation of anti-CMV therapy after achievement of sustained immune recovery. PMID:21742304

  3. An ENU-Induced Mutation in the Mertk Gene (Mertknmf12) Leads to a Slow Form of Retinal Degeneration

    PubMed Central

    Maddox, Dennis M.; Hicks, Wanda L.; Vollrath, Douglas; LaVail, Matthew M.; Naggert, Jürgen K.

    2011-01-01

    Purpose. To determine the basis and to characterize the phenotype of a chemically induced mutation in a mouse model of retinal degeneration. Methods. Screening by indirect ophthalmoscopy identified a line of N-ethyl-N-nitrosourea (ENU) mutagenized mice demonstrating retinal patches. Longitudinal studies of retinal histologic sections showed photoreceptors in the peripheral retina undergoing slow, progressive degeneration. The mutation was named neuroscience mutagenesis facility 12 (nmf12), and mapping localized the critical region to Chromosome 2. Results. Sequencing of nmf12 DNA revealed a point mutation in the c-mer tyrosine kinase gene, designated Mertknmf12. We detected elevated levels of tumor necrosis factor (Tnf, previously Tnfa) in retinas of Mertknmf12 homozygotes relative to wild-type controls and investigated whether the increase of TNF, an inflammatory cytokine produced by macrophages/monocytes that signals intracellularly to cause necrosis or apoptosis, could underlie the retinal degeneration observed in Mertknmf12 homozygotes. Mertknmf12 homozygous mice were mated to mice lacking the entire Tnf gene and partial coding sequences of the Lta (Tnfb) and Ltb (Tnfc) genes.2 B6.129P2-Ltb/Tnf/Ltatm1Dvk/J homozygotes did not exhibit a retinal degeneration phenotype and will, hereafter, be referred to as Tnfabc−/− mice. Surprisingly, mice homozygous for both the Mertknmf12 and the Ltb/Tnf/Ltatm1Dvk allele (Tnfabc−/−) demonstrated an increase in the rate of retinal degeneration. Conclusions. These findings illustrate that a mutation in the Mertk gene leads to a significantly slower progressive retinal degeneration compared with other alleles of Mertk. These results demonstrate that TNF family members play a role in protecting photoreceptors of Mertknmf12 homozygotes from cell death. PMID:21436282

  4. Optical coherence tomography parameters predictive of visual outcome after anti-VEGF therapy for retinal vein occlusion

    PubMed Central

    Fujihara-Mino, Akiko; Mitamura, Yoshinori; Inomoto, Naoki; Sano, Hiroki; Akaiwa, Kei; Semba, Kentaro

    2016-01-01

    Purpose To determine the optical coherence tomography (OCT) parameters that are predictive of visual outcome after anti-VEGF therapy for a retinal vein occlusion (RVO). Methods Fifty-seven eyes with macular edema (ME) secondary to a central or branch RVO treated with bevacizumab or ranibizumab were studied. Spectral-domain OCT and microperimetry were performed before, 1, 3, and 6 months after the treatment and at the final visit. Central retinal thickness (CRT), macular volume (MV), integrity of the external limiting membrane (ELM), ellipsoid zone (EZ), and foveal bulge (FB), and photoreceptor outer segment (PROS) length were determined. Results The mean follow-up period was 17.8±11.5 months. In 46 of the 57 eyes, a resolution of the ME was achieved. The pretreatment CRT and MV, presence of intact ELM, EZ, and FB, and PROS length at the time of ME resolution were significantly correlated with the best-corrected visual acuity and retinal sensitivity at the final visit (P<0.050). Multiple regression analyses showed that the pretreatment MV had the highest correlation with the posttreatment best-corrected visual acuity and retinal sensitivity (P<0.050). Conclusion The CRT, MV, ELM, EZ, FB, and PROS length are predictive factors for the visual outcome after anti-VEGF therapy for RVO. PMID:27486302

  5. Therapeutic effect of dexamethasone implant in retinal vein occlusions resistant to anti-VEGF therapy

    PubMed Central

    Wallsh, Josh; Sharareh, Behnam; Gallemore, Ron

    2016-01-01

    Purpose To test the efficacy of the intravitreal dexamethasone (DEX) implant in patients with retinal vein occlusions (RVOs) who have failed multiple anti-vascular endothelial growth factor (anti-VEGF) treatments. Methods A randomized exploratory study of ten patients with branch RVO or central RVO who received at least two previous anti-VEGF treatments and had persistent or unresponsive cystoid macular edema. Treatment with the DEX implant was either every 4 months or pro re nata (PRN) depending on their group assignment for 1 year. Multifocal electroretinography and microperimetry were the primary end points, with high-resolution optical coherence tomography and best-corrected visual acuity as the secondary end points. Results All patients in both the every 4 month and PRN cohorts who completed the study received the three maximal injections of DEX; therefore, the data from both cohorts were combined and reported as a case series. On average, the multifocal electroretinography amplitude increased significantly from 5.11±0.66 to 24.19±5.30 nV/deg2 at 12 months (P<0.005), mean macular sensitivity increased from 7.67±2.10 to 8.01±1.98 dB at 4 months (P=0.32), best-corrected visual acuity increased significantly from 51.0±5.1 to 55.4±5.1 early treatment of diabetic retinopathy study letters at 2 months (P<0.05), and central retinal thickness decreased from 427.6±39.5 to 367.1±37.8 μm at 4 months (P<0.05). Intraocular pressure increased significantly in one patient, with that patient requiring an additional glaucoma medication for management. Additionally, cataract progression increased significantly (P<0.05) in this patient population and partially limited analysis of other end points. Conclusion DEX should be considered as a treatment option in patients with RVOs who have failed anti-VEGF therapy, as the results of this study demonstrated an improvement in retinal morphology and macular function. Cataract progression did occur following multiple consecutive

  6. Retinitis pigmentosa and allied conditions today: a paradigm of translational research

    PubMed Central

    2010-01-01

    Monogenic human retinal dystrophies are a group of disorders characterized by progressive loss of photoreceptor cells leading to visual handicap. Retinitis pigmentosa is a type of retinal dystrophy where degeneration of rod photoreceptors occurs at the early stages. At present, there are no available effective therapies to maintain or improve vision in patients affected with retinitis pigmentosa, but post-genomic studies are allowing the development of potential therapeutic approaches. This review summarizes current knowledge on genes that have been identified to be responsible for retinitis pigmentosa, the involvement of these genes in the different forms of the disorder, the role of the proteins encoded by these genes in retinal function, the utility of genotyping, and current efforts to develop novel therapies. PMID:20519033

  7. Targeted Gene Therapies: Tools, Applications, Optimization

    PubMed Central

    Humbert, Olivier; Davis, Luther; Maizels, Nancy

    2012-01-01

    Many devastating human diseases are caused by mutations in a single gene that prevent a somatic cell from carrying out its essential functions, or by genetic changes acquired as a result of infectious disease or in the course of cell transformation. Targeted gene therapies have emerged as potential strategies for treatment of such diseases. These therapies depend upon rare-cutting endonucleases to cleave at specific sites in or near disease genes. Targeted gene correction provides a template for homology-directed repair, enabling the cell's own repair pathways to erase the mutation and replace it with the correct sequence. Targeted gene disruption ablates the disease gene, disabling its function. Gene targeting can also promote other kinds of genome engineering, including mutation, insertion, or gene deletion. Targeted gene therapies present significant advantages compared to approaches to gene therapy that depend upon delivery of stably expressing transgenes. Recent progress has been fueled by advances in nuclease discovery and design, and by new strategies that maximize efficiency of targeting and minimize off-target damage. Future progress will build on deeper mechanistic understanding of critical factors and pathways. PMID:22530743

  8. Convergence of gene and cell therapy.

    PubMed

    Bersenev, Alexey; Levine, Bruce L

    2012-11-01

    Gene therapy and cell therapy have followed similar roller coaster paths of rising public expectations and disappointment over the past two decades. There is now reason to believe that momentum in the field has reached the point where the successes will be more frequent. The use of gene-modified cells has opened new avenues for engineering desired cell properties, for the use of cells as vehicles for gene delivery, and for tracking cells and controlling cell persistence after transplantation. Some notable recent clinical developments in cellular engineering by gene transfer offer lessons on how the field has emerged, and hint at additional future clinical applications. PMID:23210811

  9. Getting arthritis gene therapy into the clinic

    PubMed Central

    Evans, Christopher H.; Ghivizzani, Steven C.; Robbins, Paul D.

    2012-01-01

    Gene transfer technologies enable the controlled, targeted and sustained expression of gene products at precise anatomical locations, such as the joint. In this way, they offer the potential for more-effective, less-expensive treatments of joint diseases with fewer extra-articular adverse effects. A large body of preclinical data confirms the utility of intra-articular gene therapy in animal models of rheumatoid arthritis and osteoarthritis. However, relatively few clinical trials have been conducted, only one of which has completed phase II. This article summarizes the status in 2010 of the clinical development of gene therapy for arthritis, identifies certain constraints to progress and suggests possible solutions. PMID:21135882

  10. European attitudes to gene therapy and pharmacogenetics.

    PubMed

    Hudson, John; Orviska, Marta

    2011-10-01

    Views on pharmacogenetics and gene therapy systematically differ across European countries. But despite a complex regulatory regime there is a balance of support, albeit laced with considerable uncertainty. PMID:21745587

  11. Gene therapy for CNS diseases - Krabbe disease.

    PubMed

    Rafi, Mohammad A

    2016-01-01

    This is a brief report of the 19th Annual Meeting of the American Society of Gene and Cell Therapy that took place from May 4th through May 7th, 2016 in Washington, DC, USA. While the meeting provided many symposiums, lectures, and scientific sessions this report mainly focuses on one of the sessions on the "Gene Therapy for central nervous system (CNS) Diseases" and specifically on the "Gene Therapy for the globoid cell leukodystrophy or Krabbe disease. Two presentations focused on this subject utilizing two animal models of this disease: mice and dog models. Different serotypes of adeno-associate viral vectors (AAV) alone or in combination with bone marrow transplantations were used in these research projects. The Meeting of the ASGCT reflected continuous growth in the fields of gene and cell therapy and brighter forecast for efficient treatment options for variety of human diseases. PMID:27525222

  12. Gene Therapy for Diseases and Genetic Disorders

    MedlinePlus

    ... notable advancements are the following: Gene Therapy for Genetic Disorders Severe Combined Immune Deficiency (ADA-SCID) ADA- ... in preclinical animal models of this disease. Other genetic disorders After many years of laboratory and preclinical ...

  13. [Tear in retinal pigment epithelium under anti-VEGF therapy for exudative age-related macular degeneration : function recovery under intensive therapy].

    PubMed

    Bartels, S; Barrelmann, A; Book, B; Heimes, B; Gutfleisch, M; Spital, G; Pauleikhoff, D; Lommatzsch, A

    2014-05-01

    This article reports the case of a 72-year-old woman with pigment epithelial detachment with occult choroidal neovascularization (CNV) in exudative age-related macular degeneration (AMD) which developed under anti-vascular endothelial growth factor (VEGF) therapy of a tear in the retinal pigment epithelium (RPE). In the area of free RPE autofluorescence was completely absent and the microperimetry in this area showed an absolute scotoma. The visual acuity was 0.1. After continuation of anti-VEGF therapy because of persistent subretinal and intraretinal fluid over 3 years an increased autofluorescence was observed and the microperimetry showed an increase in central retinal sensitivity. The central visual acuity improved to 0.5 and in this area a whitish subretinal tissue formed morphologically. In the spectral domain optical coherence tomography (SD-OCT) image this structure was hyperreflective which might suggest a certain regeneration process of the RPE under anti-VEGF-therapy. PMID:24046170

  14. Gene and cell therapy for children--new medicines, new challenges?

    PubMed

    Buckland, Karen F; Bobby Gaspar, H

    2014-06-01

    The range of possible gene and cell therapy applications is expanding at an extremely rapid rate and advanced therapy medicinal products (ATMPs) are currently the hottest topic in novel medicines, particularly for inherited diseases. Paediatric patients stand to gain enormously from these novel therapies as it now seems plausible to develop a gene or cell therapy for a vast number of inherited diseases. There are a wide variety of potential gene and cell therapies in various stages of development. Patients who received first gene therapy treatments for primary immune deficiencies (PIDs) are reaching 10 and 15 years post-treatment, with robust and sustained immune recovery. Cell therapy clinical trials are underway for a variety of tissues including corneal, retinal and muscle repair and islet cell transplantation. Various cell therapy approaches are also being trialled to enhance the safety of bone marrow transplants, which should improve survival rates in childhood cancers and PIDs. Progress in genetic engineering of lymphocyte populations to target and kill cancerous cells is also described. If successful these ATMPs may enhance or replace the existing chemo-ablative therapy for several paediatric cancers. Emerging applications of gene therapy now include skin and neurological disorders such as epidermolysis bullosa, epilepsy and leukodystrophy. Gene therapy trials for haemophilia, muscular dystrophy and a range of metabolic disorders are underway. There is a vast array of potential advanced therapy medicinal products (ATMPs), and these are likely to be more cost effective than existing medicines. However, the first clinical trials have not been without setbacks and some of the key adverse events are discussed. Furthermore, the arrival of this novel class of therapies brings many new challenges for the healthcare industry. We present a summary of the key non-clinical factors required for successful delivery of these potential treatments. Technological advances

  15. Gene and cell therapy for children — New medicines, new challenges?☆

    PubMed Central

    Buckland, Karen F.; Bobby Gaspar, H.

    2014-01-01

    The range of possible gene and cell therapy applications is expanding at an extremely rapid rate and advanced therapy medicinal products (ATMPs) are currently the hottest topic in novel medicines, particularly for inherited diseases. Paediatric patients stand to gain enormously from these novel therapies as it now seems plausible to develop a gene or cell therapy for a vast number of inherited diseases. There are a wide variety of potential gene and cell therapies in various stages of development. Patients who received first gene therapy treatments for primary immune deficiencies (PIDs) are reaching 10 and 15 years post-treatment, with robust and sustained immune recovery. Cell therapy clinical trials are underway for a variety of tissues including corneal, retinal and muscle repair and islet cell transplantation. Various cell therapy approaches are also being trialled to enhance the safety of bone marrow transplants, which should improve survival rates in childhood cancers and PIDs. Progress in genetic engineering of lymphocyte populations to target and kill cancerous cells is also described. If successful these ATMPs may enhance or replace the existing chemo-ablative therapy for several paediatric cancers. Emerging applications of gene therapy now include skin and neurological disorders such as epidermolysis bullosa, epilepsy and leukodystrophy. Gene therapy trials for haemophilia, muscular dystrophy and a range of metabolic disorders are underway. There is a vast array of potential advanced therapy medicinal products (ATMPs), and these are likely to be more cost effective than existing medicines. However, the first clinical trials have not been without setbacks and some of the key adverse events are discussed. Furthermore, the arrival of this novel class of therapies brings many new challenges for the healthcare industry. We present a summary of the key non-clinical factors required for successful delivery of these potential treatments. Technological advances

  16. Prevalence of Mutations in eyeGENE Probands With a Diagnosis of Autosomal Dominant Retinitis Pigmentosa

    PubMed Central

    Sullivan, Lori S.; Bowne, Sara J.; Reeves, Melissa J.; Blain, Delphine; Goetz, Kerry; NDifor, Vida; Vitez, Sally; Wang, Xinjing; Tumminia, Santa J.; Daiger, Stephen P.

    2013-01-01

    Purpose. To screen samples from patients with presumed autosomal dominant retinitis pigmentosa (adRP) for mutations in 12 disease genes as a contribution to the research and treatment goals of the National Ophthalmic Disease Genotyping and Phenotyping Network (eyeGENE). Methods. DNA samples were obtained from eyeGENE. A total of 170 probands with an intake diagnosis of adRP were tested through enrollment in eyeGENE. The 10 most common genes causing adRP (IMPDH1, KLHL7, NR2E3, PRPF3/RP18, PRPF31/RP11, PRPF8/RP13, PRPH2/RDS, RHO, RP1, and TOPORS) were chosen for PCR-based dideoxy sequencing, along with the two X-linked RP genes, RPGR and RP2. RHO, PRPH2, PRPF31, RPGR, and RP2 were completely sequenced, while only mutation hotspots in the other genes were analyzed. Results. Disease-causing mutations were identified in 52% of the probands. The frequencies of disease-causing mutations in the 12 genes were consistent with previous studies. Conclusions. The Laboratory for Molecular Diagnosis of Inherited Eye Disease at the University of Texas in Houston has thus far received DNA samples from 170 families with a diagnosis of adRP from the eyeGENE Network. Disease-causing mutations in autosomal genes were identified in 48% (81/170) of these families while mutations in X-linked genes accounted for an additional 4% (7/170). Of the 55 distinct mutations detected, 19 (33%) have not been previously reported. All diagnostic results were returned by eyeGENE to participating patients via their referring clinician. These genotyped samples along with their corresponding phenotypic information are also available to researchers who may request access to them for further study of these ophthalmic disorders. (ClinicalTrials.gov number, NCT00378742.) PMID:23950152

  17. Mutation spectrum of the rhodopsin gene among patients with autosomal dominant retinitis pigmentosa

    SciTech Connect

    Dryja, T.P.; Han, L.B.; Cowley, G.S.; McGee, T.L.; Berson, E.L. )

    1991-10-15

    The authors searched for point mutations in every exon of the rhodopsin gene in 150 patients from separate families with autosomal dominant retinitis pigmentosa. Including the 4 mutations the authors reported previously, they found a total of 17 different mutations that correlate with the disease. Each of these mutations is a single-base substitution corresponding to a single amino acid substitution. Based on current models for the structure of rhodopsin, 3 of the 17 mutant amino acids are normally located on the cytoplasmic side of the protein, 6 in transmembrane domains, and 8 on the intradiscal side. Forty-three of the 150 patients (29%) carry 1 of these mutations, and no patient has more than 1 mutation. In every family with a mutation so far analyzed, the mutation cosegregates with the disease. They found one instance of a mutation in an affected patient that was absent in both unaffected parents (i.e., a new germ-line mutation), indicating that some isolate cases of retinitis pigmentosa carry a mutation of the rhodopsin gene.

  18. Mutation Screening of Multiple Genes in Spanish Patients with Autosomal Recessive Retinitis Pigmentosa by Targeted Resequencing

    PubMed Central

    González-del Pozo, María; Borrego, Salud; Barragán, Isabel; Pieras, Juan I.; Santoyo, Javier; Matamala, Nerea; Naranjo, Belén; Dopazo, Joaquín; Antiñolo, Guillermo

    2011-01-01

    Retinitis Pigmentosa (RP) is a heterogeneous group of inherited retinal dystrophies characterised ultimately by the loss of photoreceptor cells. RP is the leading cause of visual loss in individuals younger than 60 years, with a prevalence of about 1 in 4000. The molecular genetic diagnosis of autosomal recessive RP (arRP) is challenging due to the large genetic and clinical heterogeneity. Traditional methods for sequencing arRP genes are often laborious and not easily available and a screening technique that enables the rapid detection of the genetic cause would be very helpful in the clinical practice. The goal of this study was to develop and apply microarray-based resequencing technology capable of detecting both known and novel mutations on a single high-throughput platform. Hence, the coding regions and exon/intron boundaries of 16 arRP genes were resequenced using microarrays in 102 Spanish patients with clinical diagnosis of arRP. All the detected variations were confirmed by direct sequencing and potential pathogenicity was assessed by functional predictions and frequency in controls. For validation purposes 4 positive controls for variants consisting of previously identified changes were hybridized on the array. As a result of the screening, we detected 44 variants, of which 15 are very likely pathogenic detected in 14 arRP families (14%). Finally, the design of this array can easily be transformed in an equivalent diagnostic system based on targeted enrichment followed by next generation sequencing. PMID:22164218

  19. Analysis of the involvement of the NR2E3 gene in autosomal recessive retinal dystrophies.

    PubMed

    Bernal, S; Solans, T; Gamundi, M J; Hernan, I; de Jorge, L; Carballo, M; Navarro, R; Tizzano, E; Ayuso, C; Baiget, M

    2008-04-01

    The nuclear receptor protein NR2E3 is postulated to play an important role in rod and cone photoreceptor development. NR2E3 gene mutational analyses were carried out in 103 unrelated subjects with different retinal diseases. A total of 14 different sequence variants were identified, including 3 mutations, 6 rare sequence variants and five polymorphisms. One of three mutations is novel (a frameshift mutation: c.1034_1038del5bp). Five of the six rare sequence variants and one of the polymorphisms identified are novel. Splice prediction programs and functional splicing assays were performed to study three of these variants. The c.119-2 A>C mutant allele construction produces, in addition to the normal one, an abnormal transcript of 180 bp resulting from an aberrant splicing with skipping of exon 2 and the generation of a premature stop codon in exon 3. These experimental data confirm the splice predictions made by the computer programs. The obtained results reinforce the idea that NR2E3 gene is involved in several retinal diseases without a clear genotype-phenotype correlation. PMID:18294254

  20. Novel deletions involving the USH2A gene in patients with Usher syndrome and retinitis pigmentosa

    PubMed Central

    García-García, Gema; Jaijo, Teresa; Aparisi, Maria J.; Larrieu, Lise; Faugère, Valérie; Blanco-Kelly, Fiona; Ayuso, Carmen; Roux, Anne-Francoise; Millán, José M.

    2014-01-01

    Purpose The aim of the present work was to identify and characterize large rearrangements involving the USH2A gene in patients with Usher syndrome and nonsyndromic retinitis pigmentosa. Methods The multiplex ligation-dependent probe amplification (MLPA) technique combined with a customized array-based comparative genomic hybridization (aCGH) analysis was applied to 40 unrelated patients previously screened for point mutations in the USH2A gene in which none or only one pathologic mutation was identified. Results We detected six large deletions involving USH2A in six out of the 40 cases studied. Three of the patients were homozygous for the deletion, and the remaining three were compound heterozygous with a previously identified USH2A point mutation. In five of these cases, the patients displayed Usher type 2, and the remaining case displayed nonsyndromic retinitis pigmentosa. The exact breakpoint junctions of the deletions found in USH2A in four of these cases were characterized. Conclusions Our study highlights the need to develop improved efficient strategies of mutation screening based upon next generation sequencing (NGS) that reduce cost, time, and complexity and allow simultaneous identification of all types of disease-causing mutations in diagnostic procedures. PMID:25352746

  1. Magnetic nanoparticles: Applications in gene delivery and gene therapy.

    PubMed

    Majidi, Sima; Zeinali Sehrig, Fatemeh; Samiei, Mohammad; Milani, Morteza; Abbasi, Elham; Dadashzadeh, Kianoosh; Akbarzadeh, Abolfazl

    2016-06-01

    Gene therapy is defined as the direct transfer of genetic material to tissues or cells for the treatment of inherited disorders and acquired diseases. For gene delivery, magnetic nanoparticles (MNPs) are typically combined with a delivery platform to encapsulate the gene, and promote cell uptake. Delivery technologies that have been used with MNPs contain polymeric, viral, as well as non-viral platforms. In this review, we focus on targeted gene delivery using MNPs. PMID:25727710

  2. Human Studies of Angiogenic Gene Therapy

    PubMed Central

    Gupta, Rajesh; Tongers, Jörn; Losordo, Douglas W.

    2009-01-01

    Despite significant advances in medical, interventional, and surgical therapy for coronary and peripheral arterial disease, the burden of these illnesses remains high. To address this unmet need, the science of therapeutic angiogenesis has been evolving for almost two decades. Early pre-clinical studies and phase I clinical trials achieved promising results with growth factors administered as recombinant proteins or as single-agent gene therapies, and data accumulated through 10 years of clinical trials indicate that gene therapy has an acceptable safety profile. However, more rigorous phase II and phase III clinical trials have failed to unequivocally demonstrate that angiogenic agents are beneficial under the conditions and in the patients studied to date. Investigators have worked to understand the biology of the vascular system and to incorporate their findings into new treatments for patients with ischemic disease. Recent gene- and cell-therapy trials have demonstrated the bioactivity of several new agents and treatment strategies. Collectively, these observations have renewed interest in the mechanisms of angiogenesis and deepened our understanding of the complexity of vascular regeneration. Gene therapy that incorporates multiple growth factors, approaches that combine cell and gene therapy, and the administration of "master switch" agents that activate numerous downstream pathways are among the credible and plausible steps forward. In this review, we will examine the clinical development of angiogenic therapy, summarize several of the lessons learned during the conduct of these trials, and suggest how this prior experience may guide the conduct of future preclinical investigations and clinical trials. PMID:19815827

  3. Strategies in Gene Therapy for Glioblastoma

    PubMed Central

    Kwiatkowska, Aneta; Nandhu, Mohan S.; Behera, Prajna; Chiocca, E. Antonio; Viapiano, Mariano S.

    2013-01-01

    Glioblastoma (GBM) is the most aggressive form of brain cancer, with a dismal prognosis and extremely low percentage of survivors. Novel therapies are in dire need to improve the clinical management of these tumors and extend patient survival. Genetic therapies for GBM have been postulated and attempted for the past twenty years, with variable degrees of success in pre-clinical models and clinical trials. Here we review the most common approaches to treat GBM by gene therapy, including strategies to deliver tumor-suppressor genes, suicide genes, immunomodulatory cytokines to improve immune response, and conditionally-replicating oncolytic viruses. The review focuses on the strategies used for gene delivery, including the most common and widely used vehicles (i.e., replicating and non-replicating viruses) as well as novel therapeutic approaches such as stem cell-mediated therapy and nanotechnologies used for gene delivery. We present an overview of these strategies, their targets, different advantages, and challenges for success. Finally, we discuss the potential of gene therapy-based strategies to effectively attack such a complex genetic target as GBM, alone or in combination with conventional therapy. PMID:24202446

  4. Gene therapy for primary immunodeficiencies: Part 1.

    PubMed

    Cavazzana-Calvo, Marina; Fischer, Alain; Hacein-Bey-Abina, Salima; Aiuti, Alessandro

    2012-10-01

    Over 60 patients affected by SCID due to IL2RG deficiency (SCID-X1) or adenosine deaminase (ADA)-SCID have received hematopoietic stem cell gene therapy in the past 15 years using gammaretroviral vectors, resulting in immune reconstitution and clinical benefit in the majority of them. However, the occurrence of insertional oncogenesis in the SCID-X1 trials has led to the development of new clinical trials based on integrating vectors with improved safety design as well as investigation on new technologies for highly efficient gene targeting and site-specific gene editing. Here we will present the experience and perspectives of gene therapy for SCID-X1 and ADA-SCID and discuss the pros and cons of gene therapy in comparison to allogeneic transplantation. PMID:22981681

  5. Gene delivery to mitotic and postmitotic photoreceptors via compacted DNA nanoparticles results in improved phenotype in a mouse model of retinitis pigmentosa.

    PubMed

    Cai, Xue; Conley, Shannon M; Nash, Zack; Fliesler, Steven J; Cooper, Mark J; Naash, Muna I

    2010-04-01

    The purpose of the present study was to test the therapeutic efficiency and safety of compacted-DNA nanoparticle-mediated gene delivery into the subretinal space of a juvenile mouse model of retinitis pigmentosa. Nanoparticles containing the mouse opsin promoter and wild-type mouse Rds gene were injected subretinally into mice carrying a haploinsufficiency mutation in the retinal degeneration slow (rds(+ or -)) gene at postnatal day (P)5 and 22. Control mice were either injected with saline, injected with uncompacted naked plasmid DNA carrying the Rds gene, or remained untreated. Rds mRNA levels peaked at postinjection day 2 to 7 (PI-2 to PI-7) for P5 injections, stabilized at levels 2-fold higher than in uninjected controls for both P5 and P22 injections, and remained elevated at the latest time point examined (PI-120). Rod function (measured by electroretinography) showed modest but statistically significant improvement compared with controls after both P5 and P22 injections. Cone function in nanoparticle-injected eyes reached wild-type levels for both ages of injections, indicating full prevention of cone degeneration. Ultrastructural examination at PI-120 revealed significant improvement in outer segment structures in P5 nanoparticle-injected eyes, while P22 injection had a modest structural improvement. There was no evidence of macrophage activation or induction of IL-6 or TNF-alpha mRNA in P5 or P22 nanoparticle-dosed eyes at either PI-2 or PI-30. Thus, compacted-DNA nanoparticles can efficiently and safely drive gene expression in both mitotic and postmitotic photoreceptors and retard degeneration in this model. These findings, using a clinically relevant treatment paradigm, illustrate the potential for application of nanoparticle-based gene replacement therapy for treatment of human retinal degenerations.-Cai, X., Conley, S. M., Nash, Z., Fliesler, S. J., Cooper, M. J., Naash, M. I. Gene delivery to mitotic and postmitotic photoreceptors via compacted DNA

  6. Morphogenesis and cytodifferentiation of the avian retinal pigmented epithelium require downregulation of Group B1 Sox genes

    PubMed Central

    Ishii, Yasuo; Weinberg, Kerry; Oda-Ishii, Izumi; Coughlin, Laura; Mikawa, Takashi

    2009-01-01

    Summary The optic vesicle is a multipotential primordium of the retina, which becomes subdivided into the neural retina and retinal pigmented epithelium domains. Although the roles of several paracrine factors in patterning the optic vesicle have been studied extensively, little is known about cell-autonomous mechanisms that regulate coordinated cell morphogenesis and cytodifferentiation of the retinal pigmented epithelium. Here we demonstrate that members of the SoxB1 gene family, Sox1, Sox2 and Sox3, are all downregulated in the presumptive retinal pigmented epithelium. Constitutive maintenance of SoxB1 expression in the presumptive retinal pigmented epithelium both in vivo and in vitro resulted in the absence of cuboidal morphology and pigmentation, and in concomitant induction of neural differentiation markers. We also demonstrate that exogenous Fgf4 inhibits downregulation all SoxB1 family members in the presumptive retinal pigment epithelium. These results suggest that retinal pigment epithelium morphogenesis and cytodifferentiation requires SoxB1 downregulation, which depends on the absence of exposure to an FGF-like signal. PMID:19570849

  7. Progression of Retinal Pigment Epithelial Atrophy in Antiangiogenic Therapy of Neovascular Age-Related Macular Degeneration

    PubMed Central

    Schütze, Christopher; Wedl, Manuela; Baumann, Bernhard; Pircher, Michael; Hitzenberger, Christoph K.; Schmidt-Erfurth, Ursula

    2015-01-01

    Purpose To monitor retinal pigment epithelial (RPE) atrophy progression during antiangiogenic therapy of neovascular age-related macular degeneration (AMD) over 2 years using polarization-sensitive optical coherence tomography (OCT). Design Prospective interventional case series. Methods setting: Clinical practice. study population: Thirty patients (31 eyes) with treatment-naïve neovascular AMD. observation procedures: Standard intravitreal therapy (0.5 mg ranibizumab) was administered monthly during the first year and pro re nata (PRN; as-needed) during the second year. Spectral-domain (SD) OCT and polarization-sensitive OCT (selectively imaging the RPE) examinations were performed at baseline and at 1, 3, 6, 12, and 24 months using a standardized protocol. RPE-related changes were evaluated using a semi-automated polarization-sensitive OCT segmentation algorithm and correlated with SD OCT and fundus autofluorescence (FAF) findings. main outcome measures: RPE response, geographic atrophy (GA) progression. Results Atrophic RPE changes included RPE thinning, RPE porosity, focal RPE atrophy, and development of GA. Early RPE loss (ie, RPE porosity, focal atrophy) increased progressively during initial monthly treatment and remained stable during subsequent PRN-based therapy. GA developed in 61% of eyes at month 24. Mean GA area increased from 0.77 mm2 at 12 months to 1.10 mm2 (standard deviation = 1.09 mm2) at 24 months. Reactive accumulation of RPE-related material at the lesion borders increased until month 3 and subsequently decreased. Conclusions Progressive RPE atrophy and GA developed in the majority of eyes. RPE migration signifies certain RPE plasticity. Polarization-sensitive OCT specifically images RPE-related changes in neovascular AMD, contrary to conventional imaging methods. Polarization-sensitive OCT allows for precisely monitoring the sequence of RPE-related morphologic changes. PMID:25769245

  8. Transcriptional Profile Analysis of RPGRORF15 Frameshift Mutation Identifies Novel Genes Associated with Retinal Degeneration

    PubMed Central

    Genini, Sem; Zangerl, Barbara; Slavik, Julianna; Acland, Gregory M.; Beltran, William A.

    2010-01-01

    Purpose. To identify genes and molecular mechanisms associated with photoreceptor degeneration in a canine model of XLRP caused by an RPGR exon ORF15 microdeletion. Methods. Expression profiles of mutant and normal retinas were compared by using canine retinal custom cDNA microarrays. qRT-PCR, Western blot analysis, and immunohistochemistry (IHC) were applied to selected genes, to confirm and expand the microarray results. Results. At 7 and 16 weeks, respectively, 56 and 18 transcripts were downregulated in the mutant retinas, but none were differentially expressed (DE) at both ages, suggesting the involvement of temporally distinct pathways. Downregulated genes included the known retina-relevant genes PAX6, CHML, and RDH11 at 7 weeks and CRX and SAG at 16 weeks. Genes directly or indirectly active in apoptotic processes were altered at 7 weeks (CAMK2G, NTRK2, PRKCB, RALA, RBBP6, RNF41, SMYD3, SPP1, and TUBB2C) and 16 weeks (SLC25A5 and NKAP). Furthermore, the DE genes at 7 weeks (ELOVL6, GLOD4, NDUFS4, and REEP1) and 16 weeks (SLC25A5 and TARS2) are related to mitochondrial functions. qRT-PCR of 18 genes confirmed the microarray results and showed DE of additional genes not on the array. Only GFAP was DE at 3 weeks of age. Western blot and IHC analyses also confirmed the high reliability of the transcriptomic data. Conclusions. Several DE genes were identified in mutant retinas. At 7 weeks, a combination of nonclassic anti- and proapoptosis genes appear to be involved in photoreceptor degeneration, whereas at both 7 and 16 weeks, the expression of mitochondria-related genes indicates that they may play a relevant role in the disease process. PMID:20574030

  9. Gene Therapy Targeting Glaucoma: Where Are We?

    PubMed Central

    Liu, Xuyang; Rasmussen, Carol A.; Gabelt, B’Ann T.; Brandt, Curtis R.; Kaufman, Paul L.

    2010-01-01

    In a chronic disease such as glaucoma, a therapy that provides a long lasting local effect, with minimal systemic side effects, while circumventing the issue of patient compliance, is very attractive. The field of gene therapy is growing rapidly and ocular applications are expanding. Our understanding of the molecular pathogenesis of glaucoma is leading to greater specificity in ocular tissue targeting. Improvements in gene delivery techniques, refinement of vector construction methods, and development of better animal models combine to bring this potential therapy closer to reality. PMID:19539835

  10. Investor Outlook: Focus on Upcoming LCA2 Gene Therapy Phase III Results.

    PubMed

    Schimmer, Joshua; Breazzano, Steven

    2015-09-01

    Investor interest in gene therapy has increased substantially over the past few years, and the next major catalyst for the field is likely to be Spark Therapeutics's phase III trial for the treatment of visual impairment caused by RPE65 gene mutations (often referred to as Leber congenital amaurosis type 2, or LCA2, but may include other retinal disorders). Analysis of the approach from the basic genetics, underlying visual mechanisms, clinical data, and commercialization considerations helps frame investor expectations and the potential implications for the broader field. PMID:26390089

  11. A case report of Epstein–Barr virus-associated retinal vasculitis: successful treatment using only acyclovir therapy

    PubMed Central

    Keorochana, Narumon

    2016-01-01

    The purpose of this study was to describe a presumed case of Epstein–Barr virus (EBV)-associated retinal vasculitis in a 42-year-old female with sudden unilateral vision loss and successful treatment with acyclovir therapy. Diagnostic vitreous biopsy of the right eye was performed to test for EBV and other known infectious causes of retinitis and evaluate vitreous cells and serological testing. Vitreous polymerase chain reaction viral DNA testing result was positive for EBV but negative for herpes simplex virus, varicella-zoster virus, and cytomegalovirus. Serologic testing was negative for toxoplasma gondii, syphilis, tuberculosis, and HIV. Histopathologic analysis of vitreous cells revealed atypical lymphocytes. Fluorescein angiography showed disk leakage, occluded retinal artery, peripheral vascular leakage, and ischemic area of the right eye. Intravenous acyclovir, 10 mg/kg/d, was prescribed for 14 days followed by oral acyclovir for 3 months. All lesions have become quiet. EBV may be a cause of retinal disease, and intravenous acyclovir is a successful treatment choice. PMID:27524923

  12. A case report of Epstein-Barr virus-associated retinal vasculitis: successful treatment using only acyclovir therapy.

    PubMed

    Keorochana, Narumon

    2016-01-01

    The purpose of this study was to describe a presumed case of Epstein-Barr virus (EBV)-associated retinal vasculitis in a 42-year-old female with sudden unilateral vision loss and successful treatment with acyclovir therapy. Diagnostic vitreous biopsy of the right eye was performed to test for EBV and other known infectious causes of retinitis and evaluate vitreous cells and serological testing. Vitreous polymerase chain reaction viral DNA testing result was positive for EBV but negative for herpes simplex virus, varicella-zoster virus, and cytomegalovirus. Serologic testing was negative for toxoplasma gondii, syphilis, tuberculosis, and HIV. Histopathologic analysis of vitreous cells revealed atypical lymphocytes. Fluorescein angiography showed disk leakage, occluded retinal artery, peripheral vascular leakage, and ischemic area of the right eye. Intravenous acyclovir, 10 mg/kg/d, was prescribed for 14 days followed by oral acyclovir for 3 months. All lesions have become quiet. EBV may be a cause of retinal disease, and intravenous acyclovir is a successful treatment choice. PMID:27524923

  13. Gene therapy for choroideremia using an adeno-associated viral (AAV) vector.

    PubMed

    Barnard, Alun R; Groppe, Markus; MacLaren, Robert E

    2015-03-01

    Choroideremia is an outer retinal degeneration with a characteristic clinical appearance that was first described in the nineteenth century. The disorder begins with reduction of night vision and gradually progresses to blindness by middle age. The appearance of the fundus in sufferers is recognizable by the characteristic pale color caused by the loss of the outer retina, retinal-pigmented epithelium, and choroidal vessels, leading to exposure of the underlying sclera. Choroideremia shows X-linked recessive inheritance and the choroideremia gene (CHM) was one of the first to be identified by positional cloning in 1990. Subsequent identification and characterization of the CHM gene, which encodes Rab escort protein 1 (REP1), has led to better comprehension of the disease and enabled advances in genetic diagnosis. Despite several decades of work to understand the exact pathogenesis, no established treatments currently exist to stop or even slow the progression of retinal degeneration in choroideremia. Encouragingly, several specific molecular and clinical features make choroideremia an ideal candidate for treatment with gene therapy. This work describes the considerations and challenges in the development of a new clinical trial using adeno-associated virus (AAV) encoding the CHM gene. PMID:25359548

  14. Gene replacement therapy for hereditary emphysema

    SciTech Connect

    Skolnick, A.

    1989-11-10

    Investigators suggest that human trials of gene therapy to correct a genetic disorder that usually leads to emphysema early in life may be only a few years away. Speaking at the American Lung Association's Second Annual Science Writers' Forum, R. G. Crystal, chief of the Pulmonary Branch of the National Heart, Lung, and Blood Institute offered an explanation of how hereditary emphysema may be more amenable to genetic therapy than other such diseases. In persons who lack a functioning gene for alpha{sup 1}-antitrypsin, a proteolytic enzyme, neutrophil elastase, attacks the walls of the lungs' alveoli, eventually leading to progressive pulmonary function loss. Two animal models of gene insertion are described.

  15. Why commercialization of gene therapy stalled; examining the life cycles of gene therapy technologies.

    PubMed

    Ledley, F D; McNamee, L M; Uzdil, V; Morgan, I W

    2014-02-01

    This report examines the commercialization of gene therapy in the context of innovation theories that posit a relationship between the maturation of a technology through its life cycle and prospects for successful product development. We show that the field of gene therapy has matured steadily since the 1980s, with the congruent accumulation of >35 000 papers, >16 000 US patents, >1800 clinical trials and >$4.3 billion in capital investment in gene therapy companies. Gene therapy technologies comprise a series of dissimilar approaches for gene delivery, each of which has introduced a distinct product architecture. Using bibliometric methods, we quantify the maturation of each technology through a characteristic life cycle S-curve, from a Nascent stage, through a Growing stage of exponential advance, toward an Established stage and projected limit. Capital investment in gene therapy is shown to have occurred predominantly in Nascent stage technologies and to be negatively correlated with maturity. Gene therapy technologies are now achieving the level of maturity that innovation research and biotechnology experience suggest may be requisite for efficient product development. Asynchrony between the maturation of gene therapy technologies and capital investment in development-focused business models may have stalled the commercialization of gene therapy. PMID:24305420

  16. Retinitis Pigmentosa

    MedlinePlus

    ... Action You are here Home › Retinal Diseases Listen Retinitis Pigmentosa What is retinitis pigmentosa? What are the symptoms? ... available? Are there any related diseases? What is retinitis pigmentosa? Retinitis pigmentosa (RP) refers to a group of ...

  17. Targeted polymeric nanoparticles for cancer gene therapy

    PubMed Central

    Kim, Jayoung; Wilson, David R.; Zamboni, Camila G.; Green, Jordan J.

    2015-01-01

    In this article, advances in designing polymeric nanoparticles for targeted cancer gene therapy are reviewed. Characterization and evaluation of biomaterials, targeting ligands, and transcriptional elements are each discussed. Advances in biomaterials have driven improvements to nanoparticle stability and tissue targeting, conjugation of ligands to the surface of polymeric nanoparticles enable binding to specific cancer cells, and the design of transcriptional elements has enabled selective DNA expression specific to the cancer cells. Together, these features have improved the performance of polymeric nanoparticles as targeted non-viral gene delivery vectors to treat cancer. As polymeric nanoparticles can be designed to be biodegradable, non-toxic, and to have reduced immunogenicity and tumorigenicity compared to viral platforms, they have significant potential for clinical use. Results of polymeric gene therapy in clinical trials and future directions for the engineering of nanoparticle systems for targeted cancer gene therapy are also presented. PMID:26061296

  18. Intravitreal Autologous Bone Marrow CD34+ Cell Therapy for Ischemic and Degenerative Retinal Disorders: Preliminary Phase 1 Clinical Trial Findings

    PubMed Central

    Park, Susanna S.; Bauer, Gerhard; Abedi, Mehrdad; Pontow, Suzanne; Panorgias, Athanasios; Jonnal, Ravi; Zawadzki, Robert J.; Werner, John S.; Nolta, Jan

    2015-01-01

    Purpose. Because human bone marrow (BM) CD34+ stem cells home into damaged tissue and may play an important role in tissue repair, this pilot clinical trial explored the safety and feasibility of intravitreal autologous CD34+ BM cells as potential therapy for ischemic or degenerative retinal conditions. Methods. This prospective study enrolled six subjects (six eyes) with irreversible vision loss from retinal vascular occlusion, hereditary or nonexudative age-related macular degeneration, or retinitis pigmentosa. CD34+ cells were isolated under Good Manufacturing Practice conditions from the mononuclear cellular fraction of the BM aspirate using a CliniMACs magnetic cell sorter. After intravitreal CD34+ cell injection, serial ophthalmic examinations, microperimetry/perimetry, fluorescein angiography, electroretinography (ERG), optical coherence tomography (OCT), and adaptive optics OCT were performed during the 6-month follow-up. Results. A mean of 3.4 million (range, 1–7 million) CD34+ cells were isolated and injected per eye. The therapy was well tolerated with no intraocular inflammation or hyperproliferation. Best-corrected visual acuity and full-field ERG showed no worsening after 6 months. Clinical examination also showed no worsening during follow-up except among age-related macular degeneration subjects in whom mild progression of geographic atrophy was noted in both the study eye and contralateral eye at 6-month follow-up, concurrent with some possible decline on multifocal ERG and microperimetry. Cellular in vivo imaging using adaptive optics OCT showed changes suggestive of new cellular incorporation into the macula of the hereditary macular degeneration study eye. Conclusions. Intravitreal autologous BM CD34+ cell therapy appears feasible and well tolerated in eyes with ischemic or degenerative retinal conditions and merits further exploration. (ClinicalTrials.gov number, NCT01736059.) PMID:25491299

  19. Employment of Salmonella in Cancer Gene Therapy.

    PubMed

    Lee, Che-Hsin

    2016-01-01

    One of the primary limitations of cancer gene therapy is lack of selectivity of the therapeutic gene to tumor cells. Current efforts are focused on discovering and developing tumor-targeting vectors that selectively target only cancer cells but spare normal cells to improve the therapeutic index. The use of preferentially tumor-targeting bacteria as vectors is one of the innovative approaches for the treatment of cancer. This is based on the observation that some obligate or facultative-anaerobic bacteria are capable of multiplying selectively in tumors and inhibiting their growth. In this study, we exploited attenuated Salmonella as a tumoricidal agent and a vector to deliver genes for tumor-targeted gene therapy. Attenuated Salmonella, carrying a eukaryotic expression plasmid encoding an anti-angiogenic gene, was used to evaluate its' ability for tumor targeting and gene delivery in murine tumor models. We also investigated the use of a polymer to modify or shield Salmonella from the pre-existing immune response in the host in order to improve gene delivery to the tumor. These results suggest that tumor-targeted gene therapy using Salmonella carrying a therapeutic gene, which exerts tumoricidal and anti-angiogenic activities, represents a promising strategy for the treatment of tumors. PMID:26846804

  20. Gene Therapy for Neurologic Manifestations of Mucopolysaccharidoses

    PubMed Central

    Wolf, Daniel A.; Banerjee, Sharbani; Hackett, Perry B.; Whitley, Chester B.; McIvor, R. Scott; Low, Walter C.

    2015-01-01

    Introduction Mucopolysaccharidoses are a family of lysosomal disorders caused by mutations in genes that encode enzymes involved in the catabolism of glycoaminoglycans. These mutations affect multiple organ systems and can be particularly deleterious to the nervous system. At the present time, enzyme replacement therapy and hematopoietic stem-cell therapy are used to treat patients with different forms of these disorders. However, to a great extent the nervous system is not adequately responsive to current therapeutic approaches. Areas Covered Recent advances in gene therapy show great promise for treating mucopolysaccharidoses. This article reviews the current state of the art for routes of delivery in developing genetic therapies for treating the neurologic manifestations of mucopolysaccharidoses. Expert Opinion Gene therapy for treating neurological manifestations of mucopolysaccharidoses can be achieved by intraventricular, intrathecal, intranasal, and systemic administration. The intraventricular route of administration appears to provide the most wide-spread distribution of gene therapy vectors to the brain. The intrathecal route of delivery results in predominant distribution to the caudal areas of the brain while the intranasal route of delivery results in good distribution to the rostral areas of brain. The systemic route of delivery via intravenous delivery can also achieve wide spread delivery to the CNS, however, the distribution to the brain is greatly dependent on the vector system. Intravenous delivery using lentiviral vectors appear to be less effective than adeno-associated viral (AAV) vectors. Moreover, some subtypes of AAV vectors are more effective than others in crossing the blood-brain-barrier. In summary, the recent advances in gene vector technology and routes of delivery to the CNS will facilitate the clinical translation of gene therapy for the treatment of the neurological manifestations of mucopolysaccharidoses. PMID:25510418

  1. Gene therapy legislation in The Netherlands.

    PubMed

    Bleijs, D A; Haenen, I T W C; Bergmans, J E N

    2007-10-01

    Several regulatory organisations are involved in the assessment of clinical gene therapy trials involving genetically modified organisms (GMOs) in The Netherlands. Medical, ethical and scientific aspects are, for instance, evaluated by the Central Committee on Research Involving Human Subjects (CCMO). The Ministry of Housing, Spatial Planning and the Environment (VROM) is the competent authority for the environmental risk assessment according to the deliberate release Directive 2001/18/EC. A Gene Therapy Office has been established in order to streamline the different national review processes and to enable the official procedures to be completed as quickly as possible. Although the Gene Therapy Office improved the application process at the national level, there is a difference of opinion between the EU member states with respect to the EU Directive according to which gene therapy trials are assessed, that urges for harmonisation. This review summarises the gene therapy legislation in The Netherlands and in particular The Netherlands rationale to follow Directive 2001/18/EC for the environmental risk assessment. PMID:17721872

  2. International perceptions and approval of gene therapy.

    PubMed

    Macer, D R; Akiyama, S; Alora, A T; Asada, Y; Azariah, J; Azariah, H; Boost, M V; Chatwachirawong, P; Kato, Y; Kaushik, V

    1995-06-01

    Gene therapy is in clinical trials in a number of countries, raising the question of whether different ethical standards can be justified in different countries. One key issue is how divergent are the perceptions and bioethical reasoning of peoples around the world. An International Bioethics Survey with 150 questions, including 35 open ones, was developed to look at how people think about diseases, life, nature, and selected issues of science and technology, biotechnology, genetic engineering, genetic screening, and gene therapy. The mail response survey was conducted in 1993 among the public in Australia, India, Israel, Japan, New Zealand, Russia, and Thailand, and the same written survey was conducted among university students in Australia, Hong Kong, India, Japan, New Zealand, The Philippines, Russia, Singapore, and Thailand. Similar questions were included in an international high school education bioethics survey among high school teachers in Australia, Japan, and New Zealand. Further international comparisons to the United States and Europe are made. About three-quarters of all samples supported personal use of gene therapy, with higher support for children's use of gene therapy. The diversity of views was generally similar within each country. The major reasons given were to save life and increase the quality of life. About 5-7% rejected gene therapy, considering it to be playing God, or unnatural. There was very little concern about eugenics (0.5-2%), and more respondents gave supportive reasons like "improving genes," especially in Thailand and India. Support for specific applications was significantly less for "improving physical characters," "improving intelligence," or "making people more ethical" than for curing diseases like cancer or diabetes, but there was little difference between inheritable or noninheritable gene therapy. PMID:7548279

  3. Diffuse choroidal hemangioma associated with exudative retinal detachment in a Sturge-Weber syndrome case: photodynamic therapy and intravitreous bevacizumab.

    PubMed

    Anaya-Pava, Edwin J; Saenz-Bocanegra, Carlos H; Flores-Trejo, Alejandro; Castro-Santana, Norma A

    2015-03-01

    We report the case of a young female patient with a diffuse choroidal hemangioma (DCH) and glaucoma as part of Sturge-Weber syndrome (SWS) and symptomatic retinal detachment that was treated successfully with photodynamic therapy (PDT) and intravitreal bevacizumab (IVB). The patient was treated with a single session of PDT, a 689-nm laser was used to deliver 50J/cm(2) with a maximum spot size of 6400μm, for 166s. IVB was administered 3 days later. The exudative retinal detachment (ERD), macular edema and visual acuity improved one week after treatment. The patient was followed for 18 months with no recurrence of ERD, and her visual acuity was preserved. PDT followed by IVB may be an effective treatment option for visual deterioration due to ERD in patients with DCHs, as are found in SWS. PMID:25560419

  4. Hyperbaric Oxygen Therapy in Branch Retinal Artery Occlusion in a 15-Year-Old Boy with Methylenetetrahydrofolate Reductase Mutation

    PubMed Central

    Kadayifcilar, Sibel; Eldem, Bora

    2015-01-01

    Purpose. To report the efficacy of hyperbaric oxygen (HBO) therapy in a case of branch retinal artery occlusion (BRAO) in a 15-year-old boy. Methods. We report a 15-year-old boy with sudden loss of vision due to BRAO. Examination included laboratory evaluation for systemic risk factors. Follow-up exams included visual acuity, fundus examination, fundus fluorescein angiography, and visual field testing. HBO therapy was employed for treatment. Results. Medical history was positive for isolated glucocorticoid deficiency. Laboratory evaluation disclosed hyperhomocysteinemia and methylenetetrahydrofolate reductase (MTHFR) mutation. The visual acuity 0.05 at presentation improved to 0.8 after 20 days of HBO therapy. There was no change on visual fields. Conclusion. In this pediatric case, HBO therapy was useful in the treatment of BRAO. PMID:25722905

  5. Towards isolation of the gene for X-linked retinitis pigmentosa (RP3)

    SciTech Connect

    Dry, K.L.; Aldred, M.A.; Hardwick, L.J.

    1994-09-01

    Until recently the region of interest containing the gene for X-linked retinitis pigmentosa (RP3) was thought to lie between CYBB (Xp21.1) and the proximal end of the deletion in patient BB (JBBprox). This region was thought to span 100-150 kb. Here we present new mapping data to show that the distance between the 5{prime} (most proximal) end of CYBB and JBBprox is only 50 kb. Recently Roux et al. (1994) have described the isolation of a gene within this region but this showed no disease-associated changes. Further evidence from mapping the deletion in patient NF (who suffered from McLead`s syndrome and CGD but not RP) and from linkage analysis of our RP3 families with a new dinucleotide repeat suggests that the gene must extend proximally from JBBprox. In order to extend the region of search we have constructed a YAC contig spanning 800 kb to OTC. We are continuing our search for the RP3 gene using a variety of strategies including exon trapping and cDNA enrichment as well as direct screening of cDNA libraries with subclones from this region.

  6. A Gene Mutated in Nephronophthisis and Retinitis Pigmentosa Encodes a Novel Protein, Nephroretinin, Conserved in Evolution

    PubMed Central

    Otto, Edgar; Hoefele, Julia; Ruf, Rainer; Mueller, Adelheid M.; Hiller, Karl S.; Wolf, Matthias T. F.; Schuermann, Maria J.; Becker, Achim; Birkenhäger, Ralf; Sudbrak, Ralf; Hennies, Hans C.; Nürnberg, Peter; Hildebrandt, Friedhelm

    2002-01-01

    Nephronophthisis (NPHP) comprises a group of autosomal recessive cystic kidney diseases, which constitute the most frequent genetic cause for end-stage renal failure in children and young adults. The most prominent histologic feature of NPHP consists of development of renal fibrosis, which, in chronic renal failure of any origin, represents the pathogenic event correlated most strongly to loss of renal function. Four gene loci for NPHP have been mapped to chromosomes 2q13 (NPHP1), 9q22 (NPHP2), 3q22 (NPHP3), and 1p36 (NPHP4). At all four loci, linkage has also been demonstrated in families with the association of NPHP and retinitis pigmentosa, known as “Senior-Løken syndrome” (SLS). Identification of the gene for NPHP type 1 had revealed nephrocystin as a novel docking protein, providing new insights into mechanisms of cell-cell and cell-matrix signaling. We here report identification of the gene (NPHP4) causing NPHP type 4, by use of high-resolution haplotype analysis and by demonstration of nine likely loss-of-function mutations in six affected families. NPHP4 encodes a novel protein, nephroretinin, that is conserved in evolution—for example, in the nematode Caenorhabditis elegans. In addition, we demonstrate two loss-of-function mutations of NPHP4 in patients from two families with SLS. Thus, we have identified a novel gene with critical roles in renal tissue architecture and ophthalmic function. PMID:12205563

  7. Spectrum of rhodopsin gene mutations in Chinese patients with retinitis pigmentosa

    PubMed Central

    Yang, Guoxing; Xie, Shipeng; Feng, Na; Yuan, Zhifeng; Zhang, Minglian

    2014-01-01

    Purpose This study was to analyze the spectrum and frequency of rhodopsin gene (RHO) mutations in Chinese patients with retinitis pigmentosa (RP). Methods Patients were given physical examinations, and blood samples were collected for DNA extraction. The RHO mutations were screened with direct sequencing. Results Eight heterozygous nucleotide changes were detected in eight of 300 probands with RP, including six novel mutations and two known mutations. p.R21C, p.C110S, p.G182V, p.C187G, c.409–426delGTGGTGGTGTGTAAGCCC, and p.P347L were found in six autosomal dominant families. p.T92I and p.Y178C were found in two isolated cases. Conclusions The results reveal the spectrum and frequency of RHO mutations in Chinese patients with different forms of RP and demonstrate that RHO mutations account for a high proportion of autosomal dominant RP (adRP) cases. PMID:25221422

  8. NIH modifies gene therapy research guidelines.

    PubMed

    Levine, Carol

    1985-06-01

    In response to public comments on the first draft of its "Points to Consider in the Design and Submission of Human Somatic-Cell Gene Therapy Protocols," the Working Group on Human Gene Therapy of the National Institutes of Health has issued a revised set of guidelines for researchers. This second draft spells out the need for public review of gene therapy protocols, the Working Group's willingness to review selected protocols before the completion of animal studies, and requirements for informed consent to long-term follow-up and to autopsy in the event of death. The document also expresses the Working Group's concern that researchers and the public be kept fully informed of the results of such studies. PMID:11643786

  9. Further screening of the rhodopsin gene in patients with autosomal dominant retinitis pigmentosa

    SciTech Connect

    Vaithinathan, R.; Berson, E.L.; Dryja, T.P. )

    1994-05-15

    Here the authors report 8 novel mutations and 8 previously reported mutations found from further analysis of the rhodopsin gene in a large set of additional patients with autosomal dominant retinitis pigmentosa. Leukocyte DNA was purified from 122 unrelated patients with autosomal dominant retinitis pigmentosa who were not included in previous analyses. The coding region and splice donor and acceptor sites of the rhodopsin gene were screened for mutations using single-strand conformation polymorphism analysis and direct genomic sequencing. They found 29 patients with varient bands that were due to mutations. Sequence analysis showed that 20 cases each had 1 of 9 previously published mutations: Pro23His, Thr58Arg, Gly89Asp, Pro171Leu, Glu181Lys, Pro347Leu, Phe45Leu, Arg135Trp, and Lys296Glu. In 9 other cases, they found 8 novel mutations. One was a 3-bp deletion (Cys264-del), and the rest were point mutations resulting in an altered amino acid: Gly51Arg (GGC [yields] CGC), Cys110Tyr (TCG [yields] TAC), Gly114Asp (GGC [yields] GAC), Ala164Glu (GCG [yields] GAG), Pro171Ser (CCA [yields] TCA), Val345Leu (GTG [yields] CTG), and Pro347Gln (CCG [yields] CAG). Each of these novel mutations was found in only one family except for Gly51Arg, which was found in two. In every family tested, the mutation cosegregated with the disease. However, in pedigree D865 only one affected member was available for analysis. About two-thirds of the mutations affect amino acids in transmembrane domains, yet only one-half of opsin's residues are in these regions. One-third of the mutations alter residues in the extracellular/intradiscal space, which includes only 25% of the protein.

  10. Improvement and decline in vision with gene therapy in childhood blindness.

    PubMed

    Jacobson, Samuel G; Cideciyan, Artur V; Roman, Alejandro J; Sumaroka, Alexander; Schwartz, Sharon B; Heon, Elise; Hauswirth, William W

    2015-05-14

    Retinal gene therapy for Leber's congenital amaurosis, an autosomal recessive childhood blindness, has been widely considered to be safe and efficacious. Three years after therapy, improvement in vision was maintained, but the rate of loss of photoreceptors in the treated retina was the same as that in the untreated retina. Here we describe long-term follow-up data from three treated patients. Topographic maps of visual sensitivity in treated regions, nearly 6 years after therapy for two of the patients and 4.5 years after therapy for the third patient, indicate progressive diminution of the areas of improved vision. (Funded by the National Eye Institute; ClinicalTrials.gov number, NCT00481546.). PMID:25936984

  11. Moving forward: cystic fibrosis gene therapy.

    PubMed

    Griesenbach, Uta; Alton, Eric W F W

    2013-10-15

    Since cloning of the CFTR gene more than 20 years ago a large number of pre-clinical and clinical CF gene therapy studies have been performed and a vast amount of information and know-how has been generated. Here, we will review key studies with a particular emphasis on clinical findings. We have learnt that the lung is a more difficult target than originally anticipated, and we describe the strength and weaknesses of the most commonly used airway gene transfer agents (GTAs). In our view, one of the most significant developments in recent years is the generation of lentiviral vectors, which efficiently transduce lung tissue. However, focused and co-ordinated efforts assessing lentiviral vector safety and scaling up of production will be required to move this vector into clinical lung gene therapy studies. PMID:23918661

  12. Ranibizumab in monotherapy and combined with photodynamic therapy for retinal angiomatous proliferation

    PubMed Central

    Arias, Luis; Gómez-Ulla, Francisco; Ruiz-Moreno, José M

    2016-01-01

    Purpose To compare the effects of intravitreal ranibizumab in monotherapy (group A) and combined with photodynamic therapy (PDT) with verteporfin (group B) in retinal angiomatous proliferation (RAP) treatment. Methods This was a multicentric, prospective, randomized clinical study conducted with parallel groups. The study eye in both groups received ranibizumab on days 1, 30, and 60 (loading dose); group B received PDT additionally on day 1. Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity (VA) testing and optical coherence tomography were performed monthly, and fluorescein angiography and indocyanine green angiography were performed quarterly. Retreatment criteria were leakage in fluorescein angiography or indocyanine green angiography, mean foveal thickness increase ≥100 µm, or VA decrease ≥5 letters. Results Twenty patients were recruited (ten patients in each group). Six eyes had previous treatment (three eyes in group A and three eyes in group B), so only 14 eyes were naïve. At 12-month follow-up, mean VA improved +1.5 letters in group A and +5.6 letters in group B (analysis of variance test; P>0.05). Two patients (20%) in both groups gained ≥15 letters (chi-square test; P>0.05). Mean changes in greatest linear dimension and in foveal thickness were not statistically significant between groups of treatment (analysis of variance test; P>0.05). Mean retreatments per patient were 1.8 (group A) and 0.9 (group B) (Mann–Whitney U-test; P>0.05). One patient died due to underlying disease not related to study medication. Conclusion Intravitreal ranibizumab administered in monotherapy or combined with PDT was efficacious in terms of VA stabilization in patients with RAP. PMID:27274190

  13. Radiopharmaceutical and Gene Therapy Program

    SciTech Connect

    Buchsbaum, Donald J.

    2006-02-09

    The objective of our research program was to determine whether novel receptors can be induced in solid cancers as a target for therapy with radiolabeled unmodified peptides that bind to the receptors. The hypothesis was that induction of a high number of receptors on the surface of these cancer cells would result in an increased uptake of the radiolabeled monomeric peptides as compared to published results with radiolabeled antibodies or peptides to naturally expressed antigens or receptors, and therefore a better therapeutic outcome. The following is a summary of published results.

  14. Evaluation of the arrestin gene in patients with retinitis pigmentosa or an allied disease

    SciTech Connect

    DeStefano, D.J.; Berson, E.L.; Dryja, T.P.

    1994-09-01

    Arrestin, also called 48K protein or S-antigen, plays a role in deactivating rhodopsin, the photosensitive, seven-helix, G-protein receptor found in rod photoreceptors. In Drosophila, null mutations in arrestin genes cause a light-dependent photoreceptor degeneration. It is possible that a comparable photoreceptor degeneration in humans is caused by defects in the rod arrestin gene. In order to evaluate this possibility, we are characterizing the human arrestin locus on chromosome 2q. We screened a genomic library (5 million plaques) using an arrestin cDNA clone. Sixty-eight hybridizing clones were identified; portions of 7 clones were sequenced to determine the intron sequence flanking the exons. We are using SSCP analysis and direct genomic sequencing to screen the entire coding region, splice donor and acceptor sites, and the promoter region of the arrestin gene in 188 patients with autosomal dominant and 104 patients with autosomal recessive retinitis pigmentosa. We have already obtained flanking intron sequences necessary for SSCP analysis for 13 of 16 exons. So far, we have identified 4 silent base changes at codons 67 (TGC-to-TGT), 107 (CTG-to-CTC), 163 (GCC-to-GCT), and 288 (CTG-to-TGT), all with allele frequencies at 1% or less. Several other variant bands detected by SSCP analysis are currently being sequenced.

  15. Indirect exclusion of four candidate genes for generalized progressive retinal atrophy in several breeds of dogs

    PubMed Central

    Lippmann, Tanja; Pasternack, Sandra M; Kraczyk, Britta; Dudek, Sabine E; Dekomien, Gabriele

    2006-01-01

    Background Generalized progressive retinal atrophy (gPRA) is a hereditary ocular disorder with progressive photoreceptor degeneration in dogs. Four retina-specific genes, ATP binding cassette transporter retina (ABCA4), connexin 36 (CX36), c-mer tyrosin kinase receptor (MERTK) and photoreceptor cell retinol dehydrogenase (RDH12) were investigated in order to identify mutations leading to autosomal recessive (ar) gPRA in 29 breeds of dogs. Results Mutation screening was performed initially by PCR and single strand conformation polymorphism (SSCP) analysis, representing a simple method with comparatively high reliability for identification of sequence variations in many samples. Conspicuous banding patterns were analyzed via sequence analyses in order to detect the underlying nucleotide variations. No pathogenetically relevant mutations were detected in the genes ABCA4, CX36, MERTK and RDH12 in 71 affected dogs of 29 breeds. Yet 30 new sequence variations were identified, both, in the coding regions and intronic sequences. Many of the sequence variations were in heterozygous state in affected dogs. Conclusion Based on the ar transmittance of gPRA in the breeds investigated, informative sequence variations provide evidence allowing indirect exclusion of pathogenetic mutations in the genes ABCA4 (for 9 breeds), CX36 (for 12 breeds), MERTK (for all 29 breeds) and RDH12 (for 9 breeds). PMID:17134500

  16. Gene therapies for inherited skin disorders.

    PubMed

    Abdul-Wahab, Alya; Qasim, Waseem; McGrath, John A

    2014-06-01

    Skin is an amenable organ for gene replacement and gene editing therapeutics. Its accessibility makes it well-suited for direct topical gene delivery, grafting of genetically corrected cells, and monitoring of possible adverse events. Monogenic recessive disorders with a clinically severe or life-threatening phenotype provide the best candidate diseases for the introduction of a single normal copy of the gene into the target cell, usually keratinocytes. Preclinical studies have shown impressive results in terms of gene correction using both in vivo and ex vivo approaches. The clinical application of gene replacement or genomic editing as potential therapies for inherited skin disorders, however, has been held back by the inadequacy of delivery vectors and concerns from regulatory agencies regarding safety; thus translation to clinical trials has been slow. Over the past 15 years, cell culture and animal models have shown efficient gene correction techniques as preludes to treat inherited skin disorders such as junctional epidermolysis bullosa, dystrophic epidermolysis bullosa, xeroderma pigmentosum, lamellar ichthyosis and Netherton syndrome, but so far only one patient has been treated in a clinical trial. This article reviews the current status of gene therapies for patients with inherited skin diseases and explores future perspectives. PMID:25085667

  17. Developments in gene therapy for muscular dystrophy.

    PubMed

    Hartigan-O'Connor, D; Chamberlain, J S

    Gene therapy for muscular dystrophy (MD) presents significant challenges, including the large amount of muscle tissue in the body, the large size of many genes defective in different muscular dystrophies, and the possibility of a host immune response against the therapeutic gene. Overcoming these challenges requires the development and delivery of suitable gene transfer vectors. Encouraging progress has been made in modifying adenovirus (Ad) vectors to reduce immune response and increase capacity. Recently developed gutted Ad vectors can deliver full-length dystrophin cDNA expression vectors to muscle tissue. Using muscle-specific promoters to drive dystrophin expression, a strong immune response has not been observed in mdx mice. Adeno-associated virus (AAV) vectors can deliver small genes to muscle without provocation of a significant immune response, which should allow long-term expression of several MD genes. AAV vectors have also been used to deliver sarcoglycan genes to entire muscle groups. These advances and others reviewed here suggest that barriers to gene therapy for MD are surmountable. PMID:10679969

  18. AAV Mediated GDNF Secretion From Retinal Glia Slows Down Retinal Degeneration in a Rat Model of Retinitis Pigmentosa

    PubMed Central

    Dalkara, Deniz; Kolstad, Kathleen D; Guerin, Karen I; Hoffmann, Natalie V; Visel, Meike; Klimczak, Ryan R; Schaffer, David V; Flannery, John G

    2011-01-01

    Mutations in over 80 identified genes can induce apoptosis in photoreceptors, resulting in blindness with a prevalence of 1 in 3,000 individuals. This broad genetic heterogeneity of disease impacting a wide range of photoreceptor functions renders the design of gene-specific therapies for photoreceptor degeneration impractical and necessitates the development of mutation-independent treatments to slow photoreceptor cell death. One promising strategy for photoreceptor neuroprotection is neurotrophin secretion from Müller cells, the primary retinal glia. Müller glia are excellent targets for secreting neurotrophins as they span the entire tissue, ensheath all neuronal populations, are numerous, and persist through retinal degeneration. We previously engineered an adeno-associated virus (AAV) variant (ShH10) capable of efficient and selective glial cell transduction through intravitreal injection. ShH10-mediated glial-derived neurotrophic factor (GDNF) secretion from glia, generates high GDNF levels in treated retinas, leading to sustained functional rescue for over 5 months. This GDNF secretion from glia following intravitreal vector administration is a safe and effective means to slow the progression of retinal degeneration in a rat model of retinitis pigmentosa (RP) and shows significant promise as a gene therapy to treat human retinal degenerations. These findings also demonstrate for the first time that glia-mediated secretion of neurotrophins is a promising treatment that may be applicable to other neurodegenerative conditions. PMID:21522134

  19. Gene Insertion Into Genomic Safe Harbors for Human Gene Therapy.

    PubMed

    Papapetrou, Eirini P; Schambach, Axel

    2016-04-01

    Genomic safe harbors (GSHs) are sites in the genome able to accommodate the integration of new genetic material in a manner that ensures that the newly inserted genetic elements: (i) function predictably and (ii) do not cause alterations of the host genome posing a risk to the host cell or organism. GSHs are thus ideal sites for transgene insertion whose use can empower functional genetics studies in basic research and therapeutic applications in human gene therapy. Currently, no fully validated GSHs exist in the human genome. Here, we review our formerly proposed GSH criteria and discuss additional considerations on extending these criteria, on strategies for the identification and validation of GSHs, as well as future prospects on GSH targeting for therapeutic applications. In view of recent advances in genome biology, gene targeting technologies, and regenerative medicine, gene insertion into GSHs can potentially catalyze nearly all applications in human gene therapy. PMID:26867951

  20. Screening for mutations in RPGR and RP2 genes in Jordanian families with X-linked retinitis pigmentosa.

    PubMed

    Haddad, M F; Khabour, O F; Abuzaideh, K A Y; Shihadeh, W

    2016-01-01

    Retinitis pigmentosa (RP) is a clinically and genetically heterogeneous disease causing progressive degeneration of retinal photoreceptor cells. X-linked RP (XLRP), in which photoreceptor degeneration begins in early childhood and complete blindness often occurs by the fourth decade of life, constitutes the most severe form of this disease. Two genes commonly associated with XLRP have previously been cloned: retinitis pigmentosa GTPase regulator (RPGR) and retinitis pigmentosa 2 (RP2). We sought to identify mutations in these genes in Jordanian families suffering from this disease. Five unrelated Jordanian families with confirmed XLRP were screened for such mutations using direct sequencing. Three mutations were identified in the ORF15 exon of RPGR. The silent g.ORF15+470G>A substitution and the g.ORF15+1822insA insertion in the 3ꞌ-untranslated region were found in both normal and affected male family members at comparable frequencies, and thus were considered normal variants. The third mutation, g.ORF15+588G>A, in which alanine is substituted by threonine, was found in all affected men and one unaffected man in the two families harboring this variant. Thus, this mutation may be pathogenic, but with incomplete penetrance. No RP2 mutations were found among the examined families. Mutation screening of RP patients is essential to understand the mechanism behind this disease and develop treatments. A complete family history is required to identify its inheritance pattern and provide genetic counseling for patients and their families. PMID:27323122

  1. Anterior chamber paracentesis after central retinal artery occlusion: a tenable therapy?

    PubMed Central

    2014-01-01

    Background The goal of this study was to investigate the visual outcome of acute central retinal artery occlusion (CRAO) after current standard therapy with and without paracentesis. In addition, we investigated whether there was a dependence of the resulting visual acuity on the time between first symptoms and implementation of paracentesis. Finally, we analysed risk factors for CRAO. Methods We performed a retrospective analysis of data from patients with CRAO who received standard in-patient therapy with and without paracentesis at the Dr. Horst Schmidt Clinics in Wiesbaden, Germany between 2000 and 2012. The primary endpoint was the change of visual acuity 3 days after the initiation of intervention. Results Data from 74 patients with CRAO were included in the study. Fifteen patients were treated conservatively and 59 patients received additional paracentesis. Clinically significant improvement of BCVA (logMAR ≥ 0.3) after 3 days was observed in 26.7% of patients without paracentesis, 36.4% of patients with paracentesis within 6 hours, 20% of patients with paracentesis within 7–24 hours, and 23.1% of patients with paracentesis more than 24 hours after the onset of symptoms. There was no significant difference in the outcome between patients with (BCVA 1.9 ± 0.31) and without paracentesis (BCVA 1.75 ± 0.32) (p = 0.9), nor among the groups with paracentesis (p = 0.8). One patient suffered a lens injury due to the paracentesis, with subsequent need for cataract surgery. Conclusions There was no added gain in visual acuity by performing a paracentesis, independent of the time elapsed between first symptoms and the implementation of paracentesis. In the absence of any tangible effectiveness of paracentesis and the inherent risks of paracentesis such as intraocular infection and injury, paracentesis does not appear to be warranted as a treatment of CRAO. PMID:24612658

  2. ORTHOPAEDIC GENE THERAPY – LOST IN TRANSLATION?

    PubMed Central

    Evans, C.H.; Ghivizzani, S.C.; Robbins, P.D.

    2011-01-01

    Orthopaedic gene therapy has been the topic of considerable research for two decades. The preclinical data are impressive and many orthopaedic conditions are well suited to genetic therapies. But there have been few clinical trials and no FDA-approved product exists. This paper examines why this is so. The reasons are multifactorial. Clinical translation is expensive and difficult to fund by traditional academic routes. Because gene therapy is viewed as unsafe and risky, it does not attract major funding from the pharmaceutical industry. Start-up companies are burdened by the complex intellectual property environment and difficulties in dealing with the technology transfer offices of major universities. Successful translation requires close interactions between scientists, clinicians and experts in regulatory and compliance issues. It is difficult to create such a favourable translational environment. Other promising fields of biological therapy have contemplated similar frustrations approximately 20 years after their founding, so there seem to be more general constraints on translation that are difficult to define. Gene therapy has noted some major clinical successes in recent years, and a sense of optimism is returning to the field. We hope that orthopaedic applications will benefit collaterally from this upswing and move expeditiously into advanced clinical trials. PMID:21948071

  3. Gene Therapy and Targeted Toxins for Glioma

    PubMed Central

    Castro, Maria G.; Candolfi, Marianela; Kroeger, Kurt; King, Gwendalyn D.; Curtin, James F.; Yagiz, Kader; Mineharu, Yohei; Assi, Hikmat; Wibowo, Mia; Muhammad, AKM Ghulam; Foulad, David; Puntel, Mariana; Lowenstein, Pedro R.

    2011-01-01

    The most common primary brain tumor in adults is glioblastoma. These tumors are highly invasive and aggressive with a mean survival time of nine to twelve months from diagnosis to death. Current treatment modalities are unable to significantly prolong survival in patients diagnosed with glioblastoma. As such, glioma is an attractive target for developing novel therapeutic approaches utilizing gene therapy. This review will examine the available preclinical models for glioma including xenographs, syngeneic and genetic models. Several promising therapeutic targets are currently being pursued in pre-clinical investigations. These targets will be reviewed by mechanism of action, i.e., conditional cytotoxic, targeted toxins, oncolytic viruses, tumor suppressors/oncogenes, and immune stimulatory approaches. Preclinical gene therapy paradigms aim to determine which strategies will provide rapid tumor regression and long-term protection from recurrence. While a wide range of potential targets are being investigated preclinically, only the most efficacious are further transitioned into clinical trial paradigms. Clinical trials reported to date are summarized including results from conditionally cytotoxic, targeted toxins, oncolytic viruses and oncogene targeting approaches. Clinical trial results have not been as robust as preclinical models predicted; this could be due to the limitations of the GBM models employed. Once this is addressed, and we develop effective gene therapies in models that better replicate the clinical scenario, gene therapy will provide a powerful approach to treat and manage brain tumors. PMID:21453286

  4. Gene Therapy and Targeted Toxins for Glioma

    PubMed Central

    King, Gwendalyn D.; Curtin, James F.; Candolfi, Marianela; Kroeger, Kurt; Lowenstein, Pedro R.; Castro, Maria G.

    2006-01-01

    The most common primary brain tumor in adults is glioblastoma. These tumors are highly invasive and aggressive with a mean survival time of nine to twelve months from diagnosis to death. Current treatment modalities are unable to significantly prolong survival in patients diagnosed with glioblastoma. As such, glioma is an attractive target for developing novel therapeutic approaches utilizing gene therapy. This review will examine the available preclinical models for glioma including xenographs, syngeneic and genetic models. Several promising therapeutic targets are currently being pursued in pre-clinical investigations. These targets will be reviewed by mechanism of action, i.e., conditional cytotoxic, targeted toxins, oncolytic viruses, tumor suppressors/oncogenes, and immune stimulatory approaches. Preclinical gene therapy paradigms aim to determine which strategies will provide rapid tumor regression and long-term protection from recurrence. While a wide range of potential targets are being investigated preclinically, only the most efficacious are further transitioned into clinical trial paradigms. Clinical trials reported to date are summarized including results from conditionally cytotoxic, targeted toxins, oncolytic viruses and oncogene targeting approaches. Clinical trial results have not been as robust as preclinical models predicted, this could be due to the limitations of the GBM models employed. Once this is addressed, and we develop effective gene therapies in models that better replicate the clinical scenario, gene therapy will provide a powerful approach to treat and manage brain tumors. PMID:16457645

  5. Gene Therapy for "Bubble Boy" Disease.

    PubMed

    Hoggatt, Jonathan

    2016-07-14

    Adenosine deaminase (ADA) deficiency results in the accumulation of toxic metabolites that destroy the immune system, causing severe combined immunodeficiency (ADA-SCID), often referred to as the "bubble boy" disease. Strimvelis is a European Medicines Agency approved gene therapy for ADA-SCID patients without a suitable bone marrow donor. PMID:27419862

  6. Theranostic Imaging of Cancer Gene Therapy.

    PubMed

    Sekar, Thillai V; Paulmurugan, Ramasamy

    2016-01-01

    Gene-directed enzyme prodrug therapy (GDEPT) is a promising therapeutic approach for treating cancers of various phenotypes. This strategy is independent of various other chemotherapeutic drugs used for treating cancers where the drugs are mainly designed to target endogenous cellular mechanisms, which are different in various cancer subtypes. In GDEPT an external enzyme, which is different from the cellular proteins, is expressed to convert the injected prodrug in to a toxic metabolite, that normally kill cancer cells express this protein. Theranostic imaging is an approach used to directly monitor the expression of these gene therapy enzymes while evaluating therapeutic effect. We recently developed a dual-GDEPT system where we combined mutant human herpes simplex thymidine kinase (HSV1sr39TK) and E. coli nitroreductase (NTR) enzyme, to improve therapeutic efficiency of cancer gene therapy by simultaneously injecting two prodrugs at a lower dose. In this approach we use two different prodrugs such as ganciclovir (GCV) and CB1954 to target two different cellular mechanisms to kill cancer cells. The developed dual GDEPT system was highly efficacious than that of either of the system used independently. In this chapter, we describe the complete protocol involved for in vitro and in vivo imaging of therapeutic cancer gene therapy evaluation. PMID:27424910

  7. Molecular genetics of X-linked retinitis pigmentosa: Progress towards cloning the RP3 gene

    SciTech Connect

    Fujita, R.; Yan, D.; McHenry, C.

    1994-09-01

    Our goal is to identify the X-linked retinitis pigmentosa (XLRP) gene RP3. The location of RP3 is genetically delimited to a region of 1 Mb, distal to DXS140, CYBB and tctex-1-like gene and proximal to the gene OTC. It is currently thought that RP3 is within 40 kb of the proximal deletion breakpoint of a patient BB. However, a more proximal location of the gene, closer to OTC, is not ruled out. We initiated the isolation of the genomic region between DXS140 to OTC in YACs. One of the clones from DXS140 region (55B) is 460 kb and spans about 200 kb at each side of BB patient`s proximal breakpoint. It contains CYBB, tctex-1-like genes and two additional CpG islands. The 55B clone has been covered by cosmid and phage subclones. Another YAC clone from the OTC region (OTCC) spans about 1 Mb and contains at least 5 CpG islands. In situ hybridization performed with OTCC showed its location in Xp21; however, several derivative cosmids map to chromosome 7, indicating that it is a chimeric YAC. No overlap is evident between 55B and OTCC. We have isolated the YAC end-sequences and isolation of clones to close the gap is in progress. Cosmids are being used for screening eye tissue cDNA libraries, mainly from retina. Screening is done by hybridization to replica filters or by cDNA enrichment methods. Several cDNA clones have been isolated and are being characterized. Exon-amplification is also being used with the cosmids and phages. Genetic analysis is being performed to determine RP3 patients from clinically indistinguishable RP2, located in Xp11.23-p11.4, and to reduce the genetic distance of current flanking markers. For this we are analyzing a number of XLRP families with established markers in the region and with new microsatellites.

  8. Mutation analysis of pre-mRNA splicing genes in Chinese families with retinitis pigmentosa

    PubMed Central

    Pan, Xinyuan; Chen, Xue; Liu, Xiaoxing; Gao, Xiang; Kang, Xiaoli; Xu, Qihua; Chen, Xuejuan; Zhao, Kanxing; Zhang, Xiumei; Chu, Qiaomei; Wang, Xiuying

    2014-01-01

    Purpose Seven genes involved in precursor mRNA (pre-mRNA) splicing have been implicated in autosomal dominant retinitis pigmentosa (adRP). We sought to detect mutations in all seven genes in Chinese families with RP, to characterize the relevant phenotypes, and to evaluate the prevalence of mutations in splicing genes in patients with adRP. Methods Six unrelated families from our adRP cohort (42 families) and two additional families with RP with uncertain inheritance mode were clinically characterized in the present study. Targeted sequence capture with next-generation massively parallel sequencing (NGS) was performed to screen mutations in 189 genes including all seven pre-mRNA splicing genes associated with adRP. Variants detected with NGS were filtered with bioinformatics analyses, validated with Sanger sequencing, and prioritized with pathogenicity analysis. Results Mutations in pre-mRNA splicing genes were identified in three individual families including one novel frameshift mutation in PRPF31 (p.Leu366fs*1) and two known mutations in SNRNP200 (p.Arg681His and p.Ser1087Leu). The patients carrying SNRNP200 p.R681H showed rapid disease progression, and the family carrying p.S1087L presented earlier onset ages and more severe phenotypes compared to another previously reported family with p.S1087L. In five other families, we identified mutations in other RP-related genes, including RP1 p. Ser781* (novel), RP2 p.Gln65* (novel) and p.Ile137del (novel), IMPDH1 p.Asp311Asn (recurrent), and RHO p.Pro347Leu (recurrent). Conclusions Mutations in splicing genes identified in the present and our previous study account for 9.5% in our adRP cohort, indicating the important role of pre-mRNA splicing deficiency in the etiology of adRP. Mutations in the same splicing gene, or even the same mutation, could correlate with different phenotypic severities, complicating the genotype–phenotype correlation and clinical prognosis. PMID:24940031

  9. Treating Immunodeficiency through HSC Gene Therapy.

    PubMed

    Booth, Claire; Gaspar, H Bobby; Thrasher, Adrian J

    2016-04-01

    Haematopoietic stem cell (HSC) gene therapy has been successfully employed as a therapeutic option to treat specific inherited immune deficiencies, including severe combined immune deficiencies (SCID) over the past two decades. Initial clinical trials using first-generation gamma-retroviral vectors to transfer corrective DNA demonstrated clinical benefit for patients, but were associated with leukemogenesis in a number of cases. Safer vectors have since been developed, affording comparable efficacy with an improved biosafety profile. These vectors are now in Phase I/II clinical trials for a number of immune disorders with more preclinical studies underway. Targeted gene editing allowing precise DNA correction via platforms such as ZFNs, TALENs and CRISPR/Cas9 may now offer promising strategies to improve the safety and efficacy of gene therapy in the future. PMID:26993219

  10. Gene and splicing therapies for neuromuscular diseases.

    PubMed

    Benchaouir, Rachid; Robin, Valerie; Goyenvalle, Aurelie

    2015-01-01

    Neuromuscular disorders (NMD) are heterogeneous group of genetic diseases characterized by muscle weakness and wasting. Duchenne Muscular dystrophy (DMD) and Spinal muscular atrophy (SMA) are two of the most common and severe forms in humans and although the molecular mechanisms of these diseases have been extensively investigated, there is currently no effective treatment. However, new gene-based therapies have recently emerged with particular noted advances in using conventional gene replacement strategies and RNA-based technology. Whilst proof of principle have been demonstrated in animal models, several clinical trials have recently been undertaken to investigate the feasibility of these strategies in patients. In particular, antisense mediated exon skipping has shown encouraging results and hold promise for the treatment of dystrophic muscle. In this review, we summarize the recent progress of therapeutic approaches to neuromuscular diseases, with an emphasis on gene therapy and splicing modulation for DMD and SMA, focusing on the advantages offered by these technologies but also their challenges. PMID:25961553

  11. Methods to improve cardiac gene therapy expression.

    PubMed

    Scimia, Maria Cecilia; Sydnes, Kate E; Zuppo, Daniel A; Koch, Walter J

    2014-11-01

    Gene therapy strategies are becoming a valuable approach for the treatment of heart failure. Some trials are ongoing and others are being organized. Vascular access in clinical experimentation is still the chosen modality of delivery, but many other approaches are in research and development. A successful gene therapy strategy involves not only the choice of the right vector and gene, but also the correct delivery strategy that allows for transduction of the highest percentage of cardiomyocytes, limited spilling of virus into other organs and the possibility to correlate the amount of injected virus to the rate of the expression within the cardiac tissue. The authors will first concentrate on clarifying what the barriers are that the virus has to overcome in order to reach the nuclei of the target organs and methodologies that have been tested to improve the range of expression. PMID:25340284

  12. Gene Therapy and Wound Healing

    PubMed Central

    Eming, Sabine A.; Krieg, Thomas; Davidson, Jeffrey M

    2007-01-01

    Wound repair involves the sequential interaction of various cell types, extracellular matrix molecules, and soluble mediators. During the past 10 years, much new information on signals controlling wound cell behavior has emerged. This knowledge has led to a number of novel_therapeutic strategies. In particular, the local delivery of pluripotent growth factor molecules to the injured tissue has been intensively investigated over the past decade. Limited success of clinical trails indicates that a crucial aspect of the growth factor wound-healing strategy is the effective delivery of these polypeptides to the wound site. A molecular approach in which genetically modified cells synthesize and deliver the desired growth factor in regulated fashion has been used to overcome the limitations associated with the (topical) application of recombinant growth factor proteins. We have summarized the molecular and cellular basis of repair mechanisms and their failure, and we give an overview of techniques and studies applied to gene transfer in tissue repair. PMID:17276205

  13. [Gene therapy in lysosomal diseases].

    PubMed

    Moullier, P; Salvetti, A; Bohl, D; Danos, O; Heard, J M

    1996-01-01

    The study of the mechanisms of secretion and recapture of lysosomal enzymes has lead to the proposal of a treatment of lysosomal diseases by enzyme replacement. Autologous implants of genetically modified cells which secrete enzymes ensure systemic distribution of the lacking enzyme. A procedure which permits reimplantation of genetically modified fibroblasts is described. The stable secretion of human glucuronidase by autologous fibroblasts was thus obtained in animal species. This approach should by applicable to the treatment of Hurler's syndrome by obtaining the production and distribution of alpha-L-iduronidase in patients lacking this enzyme by retroviral transfer of the human alpha-L-iduronidase gene to cultured fibroblasts and by preparation of implants. PMID:8881268

  14. Aerosolized Medications for Gene and Peptide Therapy.

    PubMed

    Laube, Beth L

    2015-06-01

    Inhalation therapy has matured to include drugs that: (1) deliver nucleic acids that either lead to the restoration of a gene construct or protein coding sequence in a population of cells or suppress or disrupt production of an abnormal gene product (gene therapy); (2) deliver peptides that target lung diseases such as asthma, sarcoidosis, pulmonary hypertension, and cystic fibrosis; and (3) deliver peptides to treat diseases outside the lung whose target is the systemic circulation (systemic drug delivery). These newer applications for aerosol therapy are the focus of this paper, and I discuss the status of each and the challenges that remain to their successful development. Drugs that are highlighted include: small interfering ribonucleic acid to treat lung cancer and Mycobacterium tuberculosis; vectors carrying the normal alpha-1 antitrypsin gene to treat alpha-1 antitrypsin deficiency; vectors carrying the normal cystic fibrosis transmembrane conductance regulator gene to treat cystic fibrosis; vasoactive intestinal peptide to treat asthma, pulmonary hypertension, and sarcoidosis; glutathione to treat cystic fibrosis; granulocyte-macrophage colony-stimulating factor to treat pulmonary alveolar proteinosis; calcitonin for postmenopausal osteoporosis; and insulin to treat diabetes. The success of these new aerosol applications will depend on many factors, such as: (1) developing gene therapy formulations that are safe for acute and chronic administrations to the lung, (2) improving the delivery of the genetic material beyond the airway mucus barrier and cell membrane and transferring the material to the cell cytoplasm or the cell nucleus, (3) developing aerosol devices that efficiently deliver genetic material and peptides to their lung targets over a short period of time, (4) developing devices that increase aerosol delivery to the lungs of infants, (5) optimizing the bioavailability of systemically delivered peptides, and (6) developing peptide formulations for

  15. Gene Expression Analysis of Zebrafish Melanocytes, Iridophores, and Retinal Pigmented Epithelium Reveals Indicators of Biological Function and Developmental Origin

    PubMed Central

    Higdon, Charles W.; Mitra, Robi D.; Johnson, Stephen L.

    2013-01-01

    In order to facilitate understanding of pigment cell biology, we developed a method to concomitantly purify melanocytes, iridophores, and retinal pigmented epithelium from zebrafish, and analyzed their transcriptomes. Comparing expression data from these cell types and whole embryos allowed us to reveal gene expression co-enrichment in melanocytes and retinal pigmented epithelium, as well as in melanocytes and iridophores. We found 214 genes co-enriched in melanocytes and retinal pigmented epithelium, indicating the shared functions of melanin-producing cells. We found 62 genes significantly co-enriched in melanocytes and iridophores, illustrative of their shared developmental origins from the neural crest. This is also the first analysis of the iridophore transcriptome. Gene expression analysis for iridophores revealed extensive enrichment of specific enzymes to coordinate production of their guanine-based reflective pigment. We speculate the coordinated upregulation of specific enzymes from several metabolic pathways recycles the rate-limiting substrate for purine synthesis, phosphoribosyl pyrophosphate, thus constituting a guanine cycle. The purification procedure and expression analysis described here, along with the accompanying transcriptome-wide expression data, provide the first mRNA sequencing data for multiple purified zebrafish pigment cell types, and will be a useful resource for further studies of pigment cell biology. PMID:23874447

  16. Retinal determination genes coordinate neuroepithelial specification and neurogenesis modes in the Drosophila optic lobe.

    PubMed

    Apitz, Holger; Salecker, Iris

    2016-07-01

    Differences in neuroepithelial patterning and neurogenesis modes contribute to area-specific diversifications of neural circuits. In the Drosophila visual system, two neuroepithelia, the outer (OPC) and inner (IPC) proliferation centers, generate neuron subtypes for four ganglia in several ways. Whereas neuroepithelial cells in the medial OPC directly convert into neuroblasts, in an IPC subdomain they generate migratory progenitors by epithelial-mesenchymal transition that mature into neuroblasts in a second proliferative zone. The molecular mechanisms that regulate the identity of these neuroepithelia, including their neurogenesis modes, remain poorly understood. Analysis of Polycomblike revealed that loss of Polycomb group-mediated repression of the Hox gene Abdominal-B (Abd-B) caused the transformation of OPC to IPC neuroepithelial identity. This suggests that the neuroepithelial default state is IPC-like, whereas OPC identity is derived. Ectopic Abd-B blocks expression of the highly conserved retinal determination gene network members Eyes absent (Eya), Sine oculis (So) and Homothorax (Hth). These factors are essential for OPC specification and neurogenesis control. Finally, eya and so are also sufficient to confer OPC-like identity, and, in parallel with hth, the OPC-specific neurogenesis mode on the IPC. PMID:27381228

  17. Retinal determination genes coordinate neuroepithelial specification and neurogenesis modes in the Drosophila optic lobe

    PubMed Central

    Apitz, Holger

    2016-01-01

    Differences in neuroepithelial patterning and neurogenesis modes contribute to area-specific diversifications of neural circuits. In the Drosophila visual system, two neuroepithelia, the outer (OPC) and inner (IPC) proliferation centers, generate neuron subtypes for four ganglia in several ways. Whereas neuroepithelial cells in the medial OPC directly convert into neuroblasts, in an IPC subdomain they generate migratory progenitors by epithelial-mesenchymal transition that mature into neuroblasts in a second proliferative zone. The molecular mechanisms that regulate the identity of these neuroepithelia, including their neurogenesis modes, remain poorly understood. Analysis of Polycomblike revealed that loss of Polycomb group-mediated repression of the Hox gene Abdominal-B (Abd-B) caused the transformation of OPC to IPC neuroepithelial identity. This suggests that the neuroepithelial default state is IPC-like, whereas OPC identity is derived. Ectopic Abd-B blocks expression of the highly conserved retinal determination gene network members Eyes absent (Eya), Sine oculis (So) and Homothorax (Hth). These factors are essential for OPC specification and neurogenesis control. Finally, eya and so are also sufficient to confer OPC-like identity, and, in parallel with hth, the OPC-specific neurogenesis mode on the IPC. PMID:27381228

  18. Mutations in the PDE6B gene in autosomal recessive retinitis pigmentosa

    SciTech Connect

    Danciger, M.; Blaney, J.; Gao, Y.Q.; Zhao, D.Y.

    1995-11-01

    We have studied 24 small families with presumed autosomal recessive inheritance of retinitis pigmentosa by a combination of haplotype analysis and exon screening. Initial analysis of the families was made with a dinucleotide repeat polymorphism adjacent to the gene for rod cGMP-phosphodiesterase (PDE6B). This was followed by denaturing gradient gel electrophoresis (DGGE) and single-strand conformation polymorphism electrophoresis (SSCPE) of the 22 exons and a portion of the 5{prime} untranslated region of the PDE6B gene in the probands of each family in which the PDE6B locus could not be ruled out from segregating with disease. Two probands were found with compound heterozygous mutations: Gly576Asp and His620(1-bp del) mutations were present in one proband, and a Lys706X null mutation and an AG to AT splice acceptor site mutation in intron 2 were present in the other. Only the affecteds of each of the two families carried both corresponding mutations. 29 refs., 3 figs., 1 tab.

  19. Regulation of the retinal determination gene dachshund in the embryonic head and developing eye of Drosophila

    PubMed Central

    Anderson, Jason; Salzer, Claire L.; Kumar, Justin P.

    2009-01-01

    The retinal determination gene dachshund is distantly related to the family of Ski/Sno proto-oncogenes and influences the development of a wide range of tissues including the embryonic head, optic lobes, brain, central nervous system as well as the post-embryonic leg, wing, genital and eye-antennal discs. We were interested in the regulatory mechanisms that control the dynamic expression pattern of dachshund and in this report we set out to ascertain how the transcription of dachshund is modulated in the embryonic head and developing eye-antennal imaginal disc. We demonstrate that the TGFβ signaling cascade, the transcription factor zerknullt and several other patterning genes prevent dachshund from being expressed inappropriately within the embryonic head. Additionally, we show that several members of the eye specification cascade influence the transcription of dachshund during normal and ectopic eye development. Our results suggest that dachshund is regulated by a complex combinatorial code of transcription factors and signaling pathways. Unraveling this code may lead to an understanding of how dachshund regulates the development of many diverse tissue types including the eye. PMID:16780828

  20. Gene Tests May Improve Therapy for Endometrial Cancer

    MedlinePlus

    ... External link, please review our exit disclaimer . Subscribe Gene Tests May Improve Therapy for Endometrial Cancer By analyzing genes in hundreds of endometrial tumors, scientists identified details ...

  1. Newer Gene Editing Technologies toward HIV Gene Therapy

    PubMed Central

    Manjunath, N.; Yi, Guohua; Dang, Ying; Shankar, Premlata

    2013-01-01

    Despite the great success of highly active antiretroviral therapy (HAART) in ameliorating the course of HIV infection, alternative therapeutic approaches are being pursued because of practical problems associated with life-long therapy. The eradication of HIV in the so-called “Berlin patient” who received a bone marrow transplant from a CCR5-negative donor has rekindled interest in genome engineering strategies to achieve the same effect. Precise gene editing within the cells is now a realistic possibility with recent advances in understanding the DNA repair mechanisms, DNA interaction with transcription factors and bacterial defense mechanisms. Within the past few years, four novel technologies have emerged that can be engineered for recognition of specific DNA target sequences to enable site-specific gene editing: Homing Endonuclease, ZFN, TALEN, and CRISPR/Cas9 system. The most recent CRISPR/Cas9 system uses a short stretch of complementary RNA bound to Cas9 nuclease to recognize and cleave target DNA, as opposed to the previous technologies that use DNA binding motifs of either zinc finger proteins or transcription activator-like effector molecules fused to an endonuclease to mediate sequence-specific DNA cleavage. Unlike RNA interference, which requires the continued presence of effector moieties to maintain gene silencing, the newer technologies allow permanent disruption of the targeted gene after a single treatment. Here, we review the applications, limitations and future prospects of novel gene-editing strategies for use as HIV therapy. PMID:24284874

  2. Noninvasive Tracking of Gene Transcript and Neuroprotection after Gene Therapy

    PubMed Central

    Ren, Jiaqian; Chen, Y. Iris; Liu, Christina H.; Chen, Po-Chih; Prentice, Howard; Wu, Jang-Yen; Liu, Philip K.

    2015-01-01

    Gene therapy holds exceptional potential for translational medicine by improving the products of defective genes in diseases and/or providing necessary biologics from endogenous sources during recovery processes. However, validating methods for the delivery, distribution and expression of the exogenous genes from such therapy can generally not be applicable to monitor effects over the long term because they are invasive. We report here that human granulocyte colony-stimulating factor (hG-CSF) cDNA encoded in scAAV-type 2 adeno-associated virus, as delivered through eye drops at multiple time points after cerebral ischemia using bilateral carotid occlusion for 60 min (BCAO-60) led to significant reduction in mortality rates, cerebral atrophy, and neurological deficits in C57black6 mice. Most importantly, we validated hG-CSF cDNA expression using translatable magnetic resonance imaging (MRI) in living brains. This noninvasive approach for monitoring exogenous gene expression in the brains has potential for great impact in the area of experimental gene therapy in animal models of heart attack, stroke, Alzheimer’s dementia, Parkinson’s disorder and amyotrophic lateral sclerosis, and the translation of such techniques to emergency medicine. PMID:26207935

  3. Noninvasive tracking of gene transcript and neuroprotection after gene therapy.

    PubMed

    Ren, J; Chen, Y I; Liu, C H; Chen, P-C; Prentice, H; Wu, J-Y; Liu, P K

    2016-01-01

    Gene therapy holds exceptional potential for translational medicine by improving the products of defective genes in diseases and/or providing necessary biologics from endogenous sources during recovery processes. However, validating methods for the delivery, distribution and expression of the exogenous genes from such therapy can generally not be applicable to monitor effects over the long term because they are invasive. We report here that human granulocyte colony-stimulating factor (hG-CSF) complimentary DNA (cDNA) encoded in self-complementary adeno-associated virus-type 2 adeno-associated virus, as delivered through eye drops at multiple time points after cerebral ischemia using bilateral carotid occlusion for 60 min (BCAO-60) led to significant reduction in mortality rates, cerebral atrophy and neurological deficits in C57black6 mice. Most importantly, we validated hG-CSF cDNA expression using translatable magnetic resonance imaging (MRI) in living brains. This noninvasive approach for monitoring exogenous gene expression in the brains has potential for great impact in the area of experimental gene therapy in animal models of heart attack, stroke, Alzheimer's dementia, Parkinson's disorder and amyotrophic lateral sclerosis, and the translation of such techniques to emergency medicine. PMID:26207935

  4. Gene Therapy Shows Early Promise Against Heart Failure

    MedlinePlus

    ... nlm.nih.gov/medlineplus/news/fullstory_158046.html Gene Therapy Shows Early Promise Against Heart Failure Inserting new ... who suffer from heart failure: A trial using gene therapy appears to have boosted patients' cardiac function. "This ...

  5. Gene Therapy May Offer Hope for 'Bubble Boy' Disease

    MedlinePlus

    ... nlm.nih.gov/medlineplus/news/fullstory_158415.html Gene Therapy May Offer Hope for 'Bubble Boy' Disease ... WEDNESDAY, April 20, 2016 (HealthDay News) -- A new gene therapy shows preliminary promise against so-called "Bubble ...

  6. Cloning of canine rom-1 and its investigation as a candidate gene for generalized progressive retinal atrophies in dogs.

    PubMed

    Gould, D J; Petersen-Jones, S M; Lin, C T; Sargan, D R

    1997-12-01

    Generalized progressive retinal atrophy (gPRA) represents a genetically heterogenous group of retinal degenerations affecting pedigree dogs. Currently, we are using a candidate gene approach in an attempt to identify mutations causing gPRA in dogs. Here we report the cloning, sequencing and analysis of canine rom-1, a structural gene of the rod photoreceptor. Single-stranded conformation polymorphism (SSCP) analysis was used to look for polymorphisms segregating with gPRA in the English cocker spaniel, Labrador retriever, miniature poodle, miniature long-haired dachshund, Tibetan terrier, miniature schnauzer, Cardigan Welsh corgi and Irish wolfhound. Further investigation involved DNA sequencing and restriction fragment length polymorphism (RFLP) analysis. Our studies revealed the presence of three polymorphisms, none of which segregated with disease phenotype. Haplotype analysis identified four rom-1 alleles. Our results indicate that rom-1 is unlikely to be a cause of gPRA in the breeds of dog examined. PMID:9589581

  7. Gene therapy for lysosomal disorders.

    PubMed

    Naffakh, N; Bohl, D; Salvetti, A; Moullier, P; Danos, O; Heard, J M

    1994-01-01

    Genetic defects of lysosomal hydrolases result in severe storage diseases and treatments based on enzyme replacement have been proposed. In mice lacking beta-glucuronidase, which develop a disease homologous to human mucopolysaccharidosis type VII (MPS VII, sly syndrome), we have used autologous implants of genetically-modified cells for the continuous in vivo production of the enzyme. A retroviral vector containing the human beta-glucuronidase cDNA under the control of the mouse phosphoglycerate kinase promoter was used to infect primary skin fibroblasts, bone marrow cells, or myoblasts from mutant MPS VII animals. The fibroblasts were embedded into collagen lattices and reimplanted into the peritoneal cavity of recipient MPS VII mice. All animals, when analysed 10 to 155 days later, expressed beta-glucuronidase from the vascularised neo-organs that developed after implantation, and accumulated the enzyme in their tissues. A complete disappearance of the lysosomal storage lesions was observed in their liver and spleen. This procedure has been scaled up for long term lysosomal enzyme delivery in dogs. The bone marrow cells were used for partial hematopoietic reconstruction of sublethally irradiated MPS VII mice. Five months after gene transfer, animals in which under 5% of genetically-modified hematopoietic cells were detected in the spleen showed a drastic reduction of lysosomal storage lesions in the liver and spleen. Genetically-modified myoblasts were transplanted into injured muscles, where they participated in the regeneration of a significant proportion of muscle fibers. Enzyme secretion and liver uptake were observed for at least one month.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8177709

  8. Gene Therapy for Duchenne muscular dystrophy

    PubMed Central

    Ramos, Julian; Chamberlain, Jeffrey S

    2015-01-01

    Introduction Duchenne muscular dystrophy (DMD) is a relatively common inherited disorder caused by defective expression of the protein dystrophin. The most direct approach to treating this disease would be to restore dystrophin production in muscle. Recent progress has greatly increased the prospects for successful gene therapy of DMD, and here we summarize the most promising developments. Areas Covered Gene transfer using vectors derived from adeno-associated virus (AAV) has emerged as a promising method to restore dystrophin production in muscles bodywide, and represents a treatment option applicable to all DMD patients. Using information gleaned from PubMed searches of the literature, attendance at scientific conferences and results from our own lab, we provide an overview of the potential for gene therapy of DMD using AAV vectors including a summary of promising developments and issues that need to be resolved prior to large-scale therapeutic implementation. Expert Opinion Of the many approaches being pursued to treat DMD and BMD, gene therapy based on AAV-mediated delivery of microdystrophin is the most direct and promising method to treat the cause of the disorder. The major challenges to this approach are ensuring that microdystrophin can be delivered safely and efficiently without eliciting an immune response. PMID:26594599

  9. Gene and stem cell therapy for diabetes.

    PubMed

    Calne, Roy Y; Ghoneim, Mohamed A; Lee, K O; Uin, Gan Shu

    2013-01-01

    Gene and stem cell therapy has been on the scientific agenda in many laboratories for more than 20 years. The literature is enormous, but practical applications have been few. Recently advances in stem cell biology and gene therapy are clarifying some of the issues. I have made a few observations concerning our own studies on bone marrow mesenchymal stem cells cultured to produce a small percentage of insulin-producing cells and human insulin gene engineered into Lenti and AA viruses. The aim of clinical application would still seem to be several years away, if all goes well. The first step will be to produce enough insulin-secreting cells to be of potential value to patients. The next crucial question will be how to persuade the cells to respond to blood glucose levels swiftly and appropriately. With both stem cell and gene therapy, another important factor will be to ensure that any positive results will continue long enough to be preferable to insulin injections. PMID:25095498

  10. Suicide Gene Therapy for Cancer - Current Strategies.

    PubMed

    Zarogoulidis, Paul; Darwiche, Kaid; Sakkas, Antonios; Yarmus, Lonny; Huang, Haidong; Li, Qiang; Freitag, Lutz; Zarogoulidis, Konstantinos; Malecki, Marek

    2013-08-01

    Current cancer treatments may create profound iatrogenic outcomes. The adverse effects of these treatments still remain, as the serious problems that practicing physicians have to cope with in clinical practice. Although, non-specific cytotoxic agents constitute an effective treatment modality against cancer cells, they also tend to kill normal, quickly dividing cells. On the other hand, therapies targeting the genome of the tumors are both under investigation, and some others are already streamlined to clinical practice. Several approaches have been investigated in order to find a treatment targeting the cancer cells, while not affecting the normal cells. Suicide gene therapy is a therapeutic strategy, in which cell suicide inducing transgenes are introduced into cancer cells. The two major suicide gene therapeutic strategies currently pursued are: cytosine deaminase/5-fluorocytosine and the herpes simplex virus/ganciclovir. The novel strategies include silencing gene expression, expression of intracellular antibodies blocking cells' vital pathways, and transgenic expression of caspases and DNases. We analyze various elements of cancer cells' suicide inducing strategies including: targets, vectors, and mechanisms. These strategies have been extensively investigated in various types of cancers, while exploring multiple delivery routes including viruses, non-viral vectors, liposomes, nanoparticles, and stem cells. We discuss various stages of streamlining of the suicide gene therapy into clinical oncology as applied to different types of cancer. Moreover, suicide gene therapy is in the center of attention as a strategy preventing cancer from developing in patients participating in the clinical trials of regenerative medicine. In oncology, these clinical trials are aimed at regenerating, with the aid of stem cells, of the patients' organs damaged by pathologic and/or iatrogenic factors. However, the stem cells carry the risk of neoplasmic transformation. We discuss

  11. New gene therapy strategies for hepatic fibrosis

    PubMed Central

    Salazar-Montes, Adriana M; Hernández-Ortega, Luis D; Lucano-Landeros, Martha S; Armendariz-Borunda, Juan

    2015-01-01

    The liver is the largest internal organ of the body, which may suffer acute or chronic injury induced by many factors, leading to cirrhosis and hepatocarcinoma. Cirrhosis is the irreversible end result of fibrous scarring and hepatocellular regeneration, characterized by diffuse disorganization of the normal hepatic structure, regenerative nodules and fibrotic tissue. Cirrhosis is associated with a high co-morbidity and mortality without effective treatment, and much research has been aimed at developing new therapeutic strategies to guarantee recovery. Liver-based gene therapy has been used to downregulate specific genes, to block the expression of deleterious genes, to delivery therapeutic genes, to prevent allograft rejection and to augment liver regeneration. Viral and non-viral vectors have been used, with viral vectors proving to be more efficient. This review provides an overview of the main strategies used in liver-gene therapy represented by non-viral vectors, viral vectors, novel administration methods like hydrodynamic injection, hybrids of two viral vectors and blocking molecules, with the hope of translating findings from the laboratory to the patient´s bed-side. PMID:25852266

  12. Gene therapy: prospects for glycolipid storage diseases.

    PubMed Central

    Gieselmann, Volkmar; Matzner, Ulrich; Klein, Diana; Mansson, Jan Eric; D'Hooge, Rudi; DeDeyn, Peter D; Lüllmann Rauch, Renate; Hartmann, Dieter; Harzer, Klaus

    2003-01-01

    Lysosomal storage diseases comprise a group of about 40 disorders, which in most cases are due to the deficiency of a lysosomal enzyme. Since lysosomal enzymes are involved in the degradation of various compounds, the diseases can be further subdivided according to which pathway is affected. Thus, enzyme deficiencies in the degradation pathway of glycosaminoglycans cause mucopolysaccharidosis, and deficiencies affecting glycopeptides cause glycoproteinosis. In glycolipid storage diseases enzymes are deficient that are involved in the degradation of sphingolipids. Mouse models are available for most of these diseases, and some of these mouse models have been used to study the applicability of in vivo gene therapy. We review the rationale for gene therapy in lysosomal disorders and present data, in particular, about trials in an animal model of metachromatic leukodystrophy. The data of these trials are compared with those obtained with animal models of other lysosomal diseases. PMID:12803926

  13. Gene therapy: prospects for glycolipid storage diseases.

    PubMed

    Gieselmann, Volkmar; Matzner, Ulrich; Klein, Diana; Mansson, Jan Eric; D'Hooge, Rudi; DeDeyn, Peter D; Lüllmann Rauch, Renate; Hartmann, Dieter; Harzer, Klaus

    2003-05-29

    Lysosomal storage diseases comprise a group of about 40 disorders, which in most cases are due to the deficiency of a lysosomal enzyme. Since lysosomal enzymes are involved in the degradation of various compounds, the diseases can be further subdivided according to which pathway is affected. Thus, enzyme deficiencies in the degradation pathway of glycosaminoglycans cause mucopolysaccharidosis, and deficiencies affecting glycopeptides cause glycoproteinosis. In glycolipid storage diseases enzymes are deficient that are involved in the degradation of sphingolipids. Mouse models are available for most of these diseases, and some of these mouse models have been used to study the applicability of in vivo gene therapy. We review the rationale for gene therapy in lysosomal disorders and present data, in particular, about trials in an animal model of metachromatic leukodystrophy. The data of these trials are compared with those obtained with animal models of other lysosomal diseases. PMID:12803926

  14. Pluripotent Stem Cells and Gene Therapy

    PubMed Central

    Simara, Pavel; Motl, Jason A.; Kaufman, Dan S.

    2013-01-01

    Human pluripotent stem cells represent an accessible cell source for novel cell-based clinical research and therapies. With the realization of induced pluripotent stem cells (iPSCs), it is possible to produce almost any desired cell type from any patient's cells. Current developments in gene modification methods have opened the possibility for creating genetically corrected human iPSCs for certain genetic diseases that could be used later in autologous transplantation. Promising preclinical studies have demonstrated correction of disease-causing mutations in a number of hematological, neuronal and muscular disorders. This review aims to summarize these recent advances with a focus on iPSC generation techniques, as well as gene modification methods. We will then further discuss some of the main obstacles remaining to be overcome before successful application of human pluripotent stem cell-based therapy arrives in the clinic and what the future of stem cell research may look like. PMID:23353080

  15. Advances of gene therapy for primary immunodeficiencies

    PubMed Central

    Candotti, Fabio

    2016-01-01

    In the recent past, the gene therapy field has witnessed a remarkable series of successes, many of which have involved primary immunodeficiency diseases, such as X-linked severe combined immunodeficiency, adenosine deaminase deficiency, chronic granulomatous disease, and Wiskott-Aldrich syndrome. While such progress has widened the choice of therapeutic options in some specific cases of primary immunodeficiency, much remains to be done to extend the geographical availability of such an advanced approach and to increase the number of diseases that can be targeted. At the same time, emerging technologies are stimulating intensive investigations that may lead to the application of precise genetic editing as the next form of gene therapy for these and other human genetic diseases. PMID:27508076

  16. Acute Retinal Necrosis Associated with Epstein-Barr Virus in a Patient Undergoing Immunosuppressive Therapy

    PubMed Central

    Oe, Chiaki; Hiraoka, Miki; Tanaka, Sachie; Ohguro, Hiroshi

    2016-01-01

    Acute retinal necrosis (ARN) is a rapidly progressive and severe retinitis resulting in a poor visual outcome. Infections caused by herpes viruses such as herpes simplex virus (HSV) types 1 and 2 or the varicella zoster virus (VZV) are known to be implicated in the development of ARN. In the present study, an 80-year-old female with ARN was examined. She had been affected with rheumatoid arthritis and had taken methotrexate for over 10 years. Her right eye showed clinical features of ARN, and her left eye showed mild retinitis. The genomic DNA in the aqueous humor and vitreous fluid from her right eye were analyzed by a comprehensive polymerase chain reaction (PCR) assay to screen infectious pathogens including viruses. The Epstein-Barr virus (EBV) was detected from both specimens, but neither HSV or VZV nor cytomegalovirus was detected. She underwent intraocular surgery following systemic corticosteroid and acyclovir applications. However, although the retinitis of her right eye was extinguished, the final visual outcome was blindness due to optic nerve atrophy. There are few reports indicating that EBV is associated with ARN development. The present findings suggest that EBV alone can be the causative agent of ARN. PMID:27194989

  17. Controversy over the etiology and therapy of retinal detachment: the struggles of Jules Gonin.

    PubMed

    Gloor, Balder P; Marmor, Michael F

    2013-01-01

    Retinal tears were recognized as soon as ophthalmoscopy became available. They were initially considered to be secondary events, from choroidal exudation and pressure behind the detached retina. This led von Graefe and others to recommend cuts in the retina to drain subretinal fluid into the vitreous cavity. De Wecker (1875, 1879) and Leber (1882) first proposed that intrinsic tears within the retina are the cause of retinal detachment, but they faced extreme and long lasting opposition for this view. Surgical results at this time were uniformly disastrous, and therapeutic nihilism still prevailed when Dufour and Gonin became convinced around 1904-1906 that the retinal tear was indeed the origin of the detachment. It took ten years, however, before Gonin figured out how to close tears by exact placement of heat coagulation ("thermopuncture") and provide therapeutic evidence for his beliefs. When he first presented his results in 1921, colleagues jeered at him, especially Deutschmann and Sourdille who, like the other ophthalmic surgeons, denied the role of the tear (and still made "therapeutic" incisions through the detached retina). Recognition of Gonin's approach finally came at the International Congresses in Amsterdam 1928 and in Madrid in 1933. Sourdille modified his approach when his son Gabriel convinced him to change after 1930, but Deutschmann stuck to his horrific procedure until his death in 1935. Then a new generation of retinal surgeons took over, with subsequent discussion focused on finding the best methods to close the tears. PMID:23257154

  18. Gene therapy approaches for spinal cord injury

    NASA Astrophysics Data System (ADS)

    Bright, Corinne

    As the biomedical engineering field expands, combination technologies are demonstrating enormous potential for treating human disease. In particular, intersections between the rapidly developing fields of gene therapy and tissue engineering hold promise to achieve tissue regeneration. Nonviral gene therapy uses plasmid DNA to deliver therapeutic proteins in vivo for extended periods of time. Tissue engineering employs biomedical materials, such as polymers, to support the regrowth of injured tissue. In this thesis, a combination strategy to deliver genes and drugs in a polymeric scaffold was applied to a spinal cord injury model. In order to develop a platform technology to treat spinal cord injury, several nonviral gene delivery systems and polymeric scaffolds were evaluated in vitro and in vivo. Nonviral vector trafficking was evaluated in primary neuronal culture to develop an understanding of the barriers to gene transfer in neurons and their supporting glia. Although the most efficient gene carrier in vitro differed from the optimal gene carrier in vivo, confocal and electron microscopy of these nonviral vectors provided insights into the interaction of these vectors with the nucleus. A novel pathway for delivering nanoparticles into the nuclei of neurons and Schwann cells via vesicle trafficking was observed in this study. Reporter gene expression levels were evaluated after direct and remote delivery to the spinal cord, and the optimal nonviral vector, dose, and delivery strategy were applied to deliver the gene encoding the basic fibroblast growth factor (bFGF) to the spinal cord. An injectable and biocompatible gel, composed of the amphiphillic polymer poly(ethylene glycol)-poly(epsilon-caprolactone)-poly(ethylene glycol) (PEG-PCL-PEG) was evaluated as a drug and gene delivery system in vitro, and combined with the optimized nonviral gene delivery system to treat spinal cord injury. Plasmid DNA encoding the bFGF gene and the therapeutic NEP1--40 peptide

  19. Modifier Genes as Therapeutics: The Nuclear Hormone Receptor Rev Erb Alpha (Nr1d1) Rescues Nr2e3 Associated Retinal Disease

    PubMed Central

    Cruz, Nelly M.; Yuan, Yang; Leehy, Barrett D.; Baid, Rinku; Kompella, Uday; DeAngelis, Margaret M.; Escher, Pascal; Haider, Neena B.

    2014-01-01

    Nuclear hormone receptors play a major role in many important biological processes. Most nuclear hormone receptors are ubiquitously expressed and regulate processes such as metabolism, circadian function, and development. They function in these processes to maintain homeostasis through modulation of transcriptional gene networks. In this study we evaluate the effectiveness of a nuclear hormone receptor gene to modulate retinal degeneration and restore the integrity of the retina. Currently, there are no effective treatment options for retinal degenerative diseases leading to progressive and irreversible blindness. In this study we demonstrate that the nuclear hormone receptor gene Nr1d1 (Rev-Erbα) rescues Nr2e3-associated retinal degeneration in the rd7 mouse, which lacks a functional Nr2e3 gene. Mutations in human NR2E3 are associated with several retinal degenerations including enhanced S cone syndrome and retinitis pigmentosa. The rd7 mouse, lacking Nr2e3, exhibits an increase in S cones and slow, progressive retinal degeneration. A traditional genetic mapping approach previously identified candidate modifier loci. Here, we demonstrate that in vivo delivery of the candidate modifier gene, Nr1d1 rescues Nr2e3 associated retinal degeneration. We observed clinical, histological, functional, and molecular restoration of the rd7 retina. Furthermore, we demonstrate that the mechanism of rescue at the molecular and functional level is through the re-regulation of key genes within the Nr2e3-directed transcriptional network. Together, these findings reveal the potency of nuclear receptors as modulators of disease and specifically of NR1D1 as a novel therapeutic for retinal degenerations. PMID:24498227

  20. The search for mutations in the gene for the beta subunit of the cGMP phosphodiesterase (PDEB) in patients with autosomal recessive retinitis pigmentosa

    SciTech Connect

    Riess, O.; Weber, B.; Hayden, M.R. ); Noerremoelle, A. ); Musarella, M.A. )

    1992-10-01

    The finding of a mutation in the beta subunit of the cyclic GMP (cGMP) phosphodiesterase gene causing retinal degeneration in mice (the Pdeb gene) prompted a search for disease-causing mutations in the human phosphodiesterase gene (PDEB gene) in patients with retinitis pigmentosa. All 22 exons including 196 bp of the 5[prime] region of the PDEB gene have been assessed for mutations by using single-strand conformational polymorphism analysis in 14 patients from 13 unrelated families with autosomal recessive retinitis pigmentosa (ARRP). No disease-causing mutations were found in this group of affected individuals of seven different ancestries. However, a frequent intronic and two exonic polymorphisms (Leu[sup 489][yields]Gln and Gly[sup 842][yields]Gly) were identified. Segregation analysis using these polymorphic sites excludes linkage of ARRP to the PDEB gene in a family with two affected children. 43 refs., 3 figs., 2 tabs.

  1. [Cellular therapy and gene therapy: perspectives in neuromuscular pathology].

    PubMed

    Fardeau, M

    1993-10-01

    Identification of the gene coding for the protein (dystrophin) which is lacking or abnormal in Duchenne or Becker type human muscular dystrophies was a decisive turning point in neuro-muscular pathology. Since that time, a considerable number of gene abnormalities have been identified or at least localized. The severity of these diseases, their steady evolution and the absence of any efficient drug therapy, have lead to the development of new therapeutic approaches based on restoring the genetic capacities of the muscle cell. There are two possibilities for therapy. The first is based on the transfer of myogenic cells derived from the 'satellite' cells normally present at the periphery of muscle fibers. The results obtained from a murine model of Duchenne dystrophy ('mdx' mouse) were very promising. However, the results from application of the same techniques to the canine model (GRMDX) or to affected children are, at the present time, disappointing. A number of biological questions remain to be solved before this technique can be more extensively applied to humans. The second possibility is based on gene transfer, through a viral vector. The adenovirus is presently a possible vector. The first experimental results, on 'mdx' mice, are again very encouraging. Extension of these studies to the canine model is a necessary prerequisite for any human application. It should be noted that these two approaches are complementary. Their future applications may depend on the diffuse or selective nature of the skeletal muscle atrophy, and on whether cardiac and respiratory muscles are involved. PMID:8290312

  2. Targeted Gene Therapy of Cancer: Second Amendment toward Holistic Therapy.

    PubMed

    Barar, Jaleh; Omidi, Yadollah

    2013-01-01

    It seems solid tumors are developing smart organs with specialized cells creating specified bio-territory, the so called "tumor microenvironment (TME)", in which there is reciprocal crosstalk among cancer cells, immune system cells and stromal cells. TME as an intricate milieu also consists of cancer stem cells (CSCs) that can resist against chemotherapies. In solid tumors, metabolism and vascularization appears to be aberrant and tumor interstitial fluid (TIF) functions as physiologic barrier. Thus, chemotherapy, immunotherapy and gene therapy often fail to provide cogent clinical outcomes. It looms that it is the time to accept the fact that initiation of cancer could be generation of another form of life that involves a cluster of thousands of genes, while we have failed to observe all aspects of it. Hence, the current treatment modalities need to be re-visited to cover all key aspects of disease using combination therapy based on the condition of patients. Perhaps personalized cluster of genes need to be simultaneously targeted. PMID:23878787

  3. Gene therapy approaches to regenerating bone

    PubMed Central

    Bleich, Nadav Kimelman; Kallai, Ilan; Lieberman, Jay R.; Schwarz, Edward M.; Pelled, Gadi; Gazit, Dan

    2013-01-01

    Bone formation and regeneration therapies continue to require optimization and improvement because many skeletal disorders remain undertreated. Clinical solutions to nonunion fractures and osteoporotic vertebral compression fractures, for example, remain suboptimal and better therapeutic approaches must be created. The widespread use of recombinant human bone morphogenetic proteins (rhBMPs) for spine fusion was recently questioned by a series of reports in a special issue of The Spine Journal, which elucidated the side effects and complications of direct rhBMP treatments. Gene therapy—both direct (in vivo) and cell-mediated (ex vivo)—has long been studied extensively to provide much needed improvements in bone regeneration. In this article, we review recent advances in gene therapy research whose aims are in vivo or ex vivo bone regeneration or formation. We examine appropriate vectors, safety issues, and rates of bone formation. The use of animal models and their relevance for translation of research results to the clinical setting are also discussed in order to provide the reader with a critical view. Finally, we elucidate the main challenges and hurdles faced by gene therapy aimed at bone regeneration as well as expected future trends in this field. PMID:22429662

  4. Deployment of a retinal determination gene network drives directed cell migration in the sea urchin embryo

    PubMed Central

    Martik, Megan L; McClay, David R

    2015-01-01

    Gene regulatory networks (GRNs) provide a systems-level orchestration of an organism's genome encoded anatomy. As biological networks are revealed, they continue to answer many questions including knowledge of how GRNs control morphogenetic movements and how GRNs evolve. The migration of the small micromeres to the coelomic pouches in the sea urchin embryo provides an exceptional model for understanding the genomic regulatory control of morphogenesis. An assay using the robust homing potential of these cells reveals a ‘coherent feed-forward’ transcriptional subcircuit composed of Pax6, Six3, Six1/2, Eya, and Dach1 that is responsible for the directed homing mechanism of these multipotent progenitors. The linkages of that circuit are strikingly similar to a circuit involved in retinal specification in Drosophila suggesting that systems-level tasks can be highly conserved even though the tasks drive unrelated processes in different animals. DOI: http://dx.doi.org/10.7554/eLife.08827.001 PMID:26402456

  5. Bottlenecks in Development of Retinal Therapeutic Post-Transcriptional Gene Silencing Agents

    PubMed Central

    Sullivan, Jack M.; Yau, Edwin H.; Taggart, R. Thomas; Butler, Mark C.; Kolniak, Tiffany A.

    2011-01-01

    Development of post-transcriptional gene silencing (PTGS) agents for therapeutic purposes is an immense challenge in modern biology. Established technologies used to knockdown a specific target RNA and its cognate protein: antisense, ribozyme, RNAi, all conditionally depend upon an initial, critical annealing event of the PTGS ligand to a target RNA. In this review we address the nature of the bottlenecks, emphasizing the biocomplexity of target RNA structure, that currently limit PTGS therapeutic development. We briefly review existing and emerging technologies designed to release these constraints to realize the potential of PTGS agents in gene based therapies. PMID:17976683

  6. AAV-mediated RLBP1 gene therapy improves the rate of dark adaptation in Rlbp1 knockout mice.

    PubMed

    Choi, Vivian W; Bigelow, Chad E; McGee, Terri L; Gujar, Akshata N; Li, Hui; Hanks, Shawn M; Vrouvlianis, Joanna; Maker, Michael; Leehy, Barrett; Zhang, Yiqin; Aranda, Jorge; Bounoutas, George; Demirs, John T; Yang, Junzheng; Ornberg, Richard; Wang, Yu; Martin, Wendy; Stout, Kelly R; Argentieri, Gregory; Grosenstein, Paul; Diaz, Danielle; Turner, Oliver; Jaffee, Bruce D; Police, Seshidhar R; Dryja, Thaddeus P

    2015-01-01

    Recessive mutations in RLBP1 cause a form of retinitis pigmentosa in which the retina, before its degeneration leads to blindness, abnormally slowly recovers sensitivity after exposure to light. To develop a potential gene therapy for this condition, we tested multiple recombinant adeno-associated vectors (rAAVs) composed of different promoters, capsid serotypes, and genome conformations. We generated rAAVs in which sequences from the promoters of the human RLBP1, RPE65, or BEST1 genes drove the expression of a reporter gene (green fluorescent protein). A promoter derived from the RLBP1 gene mediated expression in the retinal pigment epithelium and Müller cells (the intended target cell types) at qualitatively higher levels than in other retinal cell types in wild-type mice and monkeys. With this promoter upstream of the coding sequence of the human RLBP1 gene, we compared the potencies of vectors with an AAV2 versus an AAV8 capsid in transducing mouse retinas, and we compared vectors with a self-complementary versus a single-stranded genome. The optimal vector (scAAV8-pRLBP1-hRLBP1) had serotype 8 capsid and a self-complementary genome. Subretinal injection of scAAV8-pRLBP1-hRLBP1 in Rlbp1 nullizygous mice improved the rate of dark adaptation based on scotopic (rod-plus-cone) and photopic (cone) electroretinograms (ERGs). The effect was still present after 1 year. PMID:26199951

  7. AAV-mediated RLBP1 gene therapy improves the rate of dark adaptation in Rlbp1 knockout mice

    PubMed Central

    Choi, Vivian W; Bigelow, Chad E; McGee, Terri L; Gujar, Akshata N; Li, Hui; Hanks, Shawn M; Vrouvlianis, Joanna; Maker, Michael; Leehy, Barrett; Zhang, Yiqin; Aranda, Jorge; Bounoutas, George; Demirs, John T; Yang, Junzheng; Ornberg, Richard; Wang, Yu; Martin, Wendy; Stout, Kelly R; Argentieri, Gregory; Grosenstein, Paul; Diaz, Danielle; Turner, Oliver; Jaffee, Bruce D; Police, Seshidhar R; Dryja, Thaddeus P

    2015-01-01

    Recessive mutations in RLBP1 cause a form of retinitis pigmentosa in which the retina, before its degeneration leads to blindness, abnormally slowly recovers sensitivity after exposure to light. To develop a potential gene therapy for this condition, we tested multiple recombinant adeno-associated vectors (rAAVs) composed of different promoters, capsid serotypes, and genome conformations. We generated rAAVs in which sequences from the promoters of the human RLBP1, RPE65, or BEST1 genes drove the expression of a reporter gene (green fluorescent protein). A promoter derived from the RLBP1 gene mediated expression in the retinal pigment epithelium and Müller cells (the intended target cell types) at qualitatively higher levels than in other retinal cell types in wild-type mice and monkeys. With this promoter upstream of the coding sequence of the human RLBP1 gene, we compared the potencies of vectors with an AAV2 versus an AAV8 capsid in transducing mouse retinas, and we compared vectors with a self-complementary versus a single-stranded genome. The optimal vector (scAAV8-pRLBP1-hRLBP1) had serotype 8 capsid and a self-complementary genome. Subretinal injection of scAAV8-pRLBP1-hRLBP1 in Rlbp1 nullizygous mice improved the rate of dark adaptation based on scotopic (rod-plus-cone) and photopic (cone) electroretinograms (ERGs). The effect was still present after 1 year. PMID:26199951

  8. Creating a cardiac pacemaker by gene therapy.

    PubMed

    Anghel, Traian M; Pogwizd, Steven M

    2007-02-01

    While electronic cardiac pacing in its various modalities represents standard of care for treatment of symptomatic bradyarrhythmias and heart failure, it has limitations ranging from absent or rudimentary autonomic modulation to severe complications. This has prompted experimental studies to design and validate a biological pacemaker that could supplement or replace electronic pacemakers. Advances in cardiac gene therapy have resulted in a number of strategies focused on beta-adrenergic receptors as well as specific ion currents that contribute to pacemaker function. This article reviews basic pacemaker physiology, as well as studies in which gene transfer approaches to develop a biological pacemaker have been designed and validated in vivo. Additional requirements and refinements necessary for successful biopacemaker function by gene transfer are discussed. PMID:17139515

  9. Concepts in Gene Therapy for Cartilage Repair

    PubMed Central

    Steinert, Andre F.; Nöth, Ulrich; Tuan, Rocky S.

    2009-01-01

    Summary Once articular cartilage is injured, it has a very limited capacity for self-repair. Although current surgical therapeutic procedures to cartilage repair are clinically useful, they cannot restore a normal articular surface. Current research offers a growing number of bioactive reagents, including proteins and nucleic acids, that may be used to augment different aspects of the repair process. As these agents are difficult to administer effectively, gene transfer approaches are being developed to provide their sustained synthesis at sites of repair. To augment regeneration of articular cartilage, therapeutic genes can be delivered to the synovium, or directly to the cartilage lesion. Gene delivery to the cells of the synovial lining is generally considered more suitable for chondroprotective approaches, based on the expression of anti-inflammatory mediators. Gene transfer targeted to cartilage defects can be achieved by either direct vector administration to cells located at or surrounding the defects, or by transplantation of genetically modified chondrogenic cells into the defect. Several studies have shown that exogenous cDNAs encoding growth factors can be delivered locally to sites of cartilage damage, where they are expressed at therapeutically relevant levels. Furthermore, data is beginning to emerge indicating, that efficient delivery and expression of these genes is capable of influencing a repair response toward the synthesis of a more hyaline cartilage repair tissue in vivo. This review presents the current status of gene therapy for cartilage healing and highlights some of the remaining challenges. PMID:18313477

  10. Spectral sensitivity measurements reveal partial success in restoring missing rod function with gene therapy.

    PubMed

    Ripamonti, Caterina; Henning, G Bruce; Robbie, Scott J; Sundaram, Venki; van den Born, L Ingeborgh; Casteels, Ingele; de Ravel, Thomy J L; Moore, Anthony T; Smith, Alexander J; Bainbridge, James W; Ali, Robin R; Stockman, Andrew

    2015-01-01

    Restored rod visual function after gene therapy can be established unequivocally by demonstrating that, after dark adaptation, spectral sensitivity has the shape characteristic of rods and that this shape collapses to a cone-like shape before rods have recovered after an intense bleach. We used these tests to assess retinal function in eight young adults and children with early-onset severe retinal dystrophy from Phase II of a clinical gene-therapy trial for RPE65 deficiency that involved the subretinal delivery of a recombinant adeno-associated viral vector carrying RPE65. We found substantial improvements in rod sensitivity in two participants: dark-adapted spectral sensitivity was rod-like after treatment and was cone-like before rods had recovered after a bleach. After 40 min of dark adaptation, one participant showed up to 1,000-fold sensitivity improvements 4 months after treatment and the second up to 100-fold improvements 6 months after treatment. The dark-adapted spectral sensitivities of the other six participants remained cone-like and showed little improvement in sensitivity. PMID:26605849

  11. Halting progressive neurodegeneration in advanced retinitis pigmentosa

    PubMed Central

    Koch, Susanne F.; Tsai, Yi-Ting; Duong, Jimmy K.; Wu, Wen-Hsuan; Hsu, Chun-Wei; Wu, Wei-Pu; Bonet-Ponce, Luis; Lin, Chyuan-Sheng; Tsang, Stephen H.

    2015-01-01

    Hereditary retinal degenerative diseases, such as retinitis pigmentosa (RP), are characterized by the progressive loss of rod photoreceptors followed by loss of cones. While retinal gene therapy clinical trials demonstrated temporary improvement in visual function, this approach has yet to achieve sustained functional and anatomical rescue after disease onset in patients. The lack of sustained benefit could be due to insufficient transduction efficiency of viral vectors (“too little”) and/or because the disease is too advanced (“too late”) at the time therapy is initiated. Here, we tested the latter hypothesis and developed a mouse RP model that permits restoration of the mutant gene in all diseased photoreceptor cells, thereby ensuring sufficient transduction efficiency. We then treated mice at early, mid, or late disease stages. At all 3 time points, degeneration was halted and function was rescued for at least 1 year. Not only do our results demonstrate that gene therapy effectively preserves function after the onset of degeneration, our study also demonstrates that there is a broad therapeutic time window. Moreover, these results suggest that RP patients are treatable, despite most being diagnosed after substantial photoreceptor loss, and that gene therapy research must focus on improving transduction efficiency to maximize clinical impact. PMID:26301813

  12. A novel platform for minimally invasive delivery of cellular therapy as a thin layer across the subretina for treatment of retinal degeneration

    NASA Astrophysics Data System (ADS)

    Rotenstreich, Ygal; Tzameret, Adi; Kalish, Sapir E.; Belkin, Michael; Meir, Amilia; Treves, Avraham J.; Nagler, Arnon; Sher, Ifat

    2015-03-01

    Incurable retinal degenerations affect millions worldwide. Stem cell transplantation rescued visual functions in animal models of retinal degeneration. In those studies cells were transplanted in subretinal "blebs", limited number of cells could be injected and photoreceptor rescue was restricted to areas in proximity to the injection sites. We developed a minimally-invasive surgical platform for drug and cell delivery in a thin layer across the subretina and extravascular spaces of the choroid. The novel system is comprised of a syringe with a blunt-tipped needle and an adjustable separator. Human bone marrow mesenchymal stem cells (hBM-MSCs) were transplanted in eyes of RCS rats and NZW rabbits through a longitudinal triangular scleral incision. No immunosuppressants were used. Retinal function was determined by electroretinogram analysis and retinal structure was determined by histological analysis and OCT. Transplanted cells were identified as a thin layer across the subretina and extravascular spaces of the choroid. In RCS rats, cell transplantation delayed photoreceptor degeneration across the entire retina and significantly enhanced retinal functions. No retinal detachment or choroidal hemorrhages were observed in rabbits following transplantation. This novel platform opens a new avenue for drug and cell delivery, placing the transplanted cells in close proximity to the damaged RPE and retina as a thin layer, across the subretina and thereby slowing down cell death and photoreceptor degeneration, without retinal detachment or choroidal hemorrhage. This new transplantation system may increase the therapeutic effect of other cell-based therapies and therapeutic agents. This study is expected to directly lead to phase I/II clinical trials for autologous hBM-MSCs transplantation in retinal degeneration patients.

  13. [The nurse's work in the application of ozone therapy in retinitis pigmentosa. January-May 1996].

    PubMed

    Guerra Veranes, X; Limonta Nápoles, Y; Contrera Hechavarría, I; Freyre Luque, R; Martínez Blanco, C

    1998-01-01

    A descriptive and prospective study of 73 patients suffering from retinitis pigmentosa, who were attended at the Provincial Center of Retinitis Pigmentosa, in Santiago de Cuba, from January to May, 1996, was conducted aimed at emphasizing the nurse's role in the application of ozonotherapy. There are different ways to administer this gast: autohemotherapy, intramuscular, artrectal insufflation. The information obtained was manually processed and percentage was used as a summary measure. The predominance of young and male patients is among the main results. Most of the patients were in stage II and III of the disease, and the rectal administration of ozone was the most used. This last aspect shows the significance of the nurse-patient relationship, which contributed decisively to the acceptance of rectal administration that was rejected by a great number of patients. PMID:9934231

  14. Temporal retinal transcriptome and systems biology analysis identifies key pathways and hub genes in Staphylococcus aureus endophthalmitis

    PubMed Central

    Rajamani, Deepa; Singh, Pawan Kumar; Rottmann, Bruce G.; Singh, Natasha; Bhasin, Manoj K.; Kumar, Ashok

    2016-01-01

    Bacterial endophthalmitis remains a devastating inflammatory condition associated with permanent vision loss. Hence, assessing the host response in this disease may provide new targets for intervention. Using a mouse model of Staphylococcus aureus (SA) endophthalmitis and performing retinal transcriptome analysis, we discovered progressive changes in the expression of 1,234 genes. Gene ontology (GO) and pathway analyses revealed the major pathways impacted in endophthalmitis includes: metabolism, inflammatory/immune, antimicrobial, cell trafficking, and lipid biosynthesis. Among the immune/inflammation pathways, JAK/Stat and IL-17A signaling were the most significantly affected. Interactive network-based analyses identified 13 focus hub genes (IL-6, IL-1β, CXCL2, STAT3, NUPR1, Jun, CSF1, CYR61, CEBPB, IGF-1, EGFR1, SPP1, and TGM2) within these important pathways. The expression of hub genes confirmed by qRT-PCR, ELISA (IL-6, IL-1β, and CXCL2), and Western blot or immunostaining (CEBP, STAT3, NUPR1, and IGF1) showed strong correlation with transcriptome data. Since TLR2 plays an important role in SA endophthalmitis, counter regulation analysis of TLR2 ligand pretreated retina or the use of retinas from TLR2 knockout mice showed the down-regulation of inflammatory regulatory genes. Collectively, our study provides, for the first time, a comprehensive analysis of the transcriptomic response and identifies key pathways regulating retinal innate responses in staphylococcal endophthalmitis. PMID:26865111

  15. A novel mutation of the RP1 gene (Lys778ter) associated with autosomal dominant retinitis pigmentosa

    PubMed Central

    Dietrich, K; Jacobi, F K; Tippmann, S; Schmid, R; Zrenner, E; Wissinger, B; Apfelstedt-Sylla, E

    2002-01-01

    Background: Besides the three known genes (RHO, RDS/Peripherin, NRL) involved in autosomal dominant retinitis pigmentosa (adRP), a fourth gene, RP1, has been recently identified. Initial reports suggest that mutations in the RP1 gene are the second most frequent cause of adRP. The clinical findings were described in a family with adRP and a novel mutation in the RP1 gene. Method: Index patients from 15 independent families with adRP in which RHO mutations had been excluded in previous examinations were screened for mutations in the RP1 gene by means of direct DNA sequencing. Evaluation of the RP1 phenotype in patients included funduscopy, kinetic perimetry, dark adapted final threshold test, standard electroretinography and, in one case, multifocal electroretinography. Results: One novel nonsense mutation (Lys778ter) in one of these 15 patients was detected. Cosegregation of the mutation with the disease phenotype could be established in the index patient's family. The phenotype comprises variable expression of clinical disease probably including one case of incomplete penetrance, a onset of symptoms beginning in adulthood, and evidence of regionally varying retinal function loss. Conclusion: The Lys778ter mutation localises inside the critical region harbouring all mutations described so far. The ophthalmic findings support previous observations that variation of disease expression appears as a typical feature of the RP1 phenotype. PMID:11864893

  16. Temporal retinal transcriptome and systems biology analysis identifies key pathways and hub genes in Staphylococcus aureus endophthalmitis.

    PubMed

    Rajamani, Deepa; Singh, Pawan Kumar; Rottmann, Bruce G; Singh, Natasha; Bhasin, Manoj K; Kumar, Ashok

    2016-01-01

    Bacterial endophthalmitis remains a devastating inflammatory condition associated with permanent vision loss. Hence, assessing the host response in this disease may provide new targets for intervention. Using a mouse model of Staphylococcus aureus (SA) endophthalmitis and performing retinal transcriptome analysis, we discovered progressive changes in the expression of 1,234 genes. Gene ontology (GO) and pathway analyses revealed the major pathways impacted in endophthalmitis includes: metabolism, inflammatory/immune, antimicrobial, cell trafficking, and lipid biosynthesis. Among the immune/inflammation pathways, JAK/Stat and IL-17A signaling were the most significantly affected. Interactive network-based analyses identified 13 focus hub genes (IL-6, IL-1β, CXCL2, STAT3, NUPR1, Jun, CSF1, CYR61, CEBPB, IGF-1, EGFR1, SPP1, and TGM2) within these important pathways. The expression of hub genes confirmed by qRT-PCR, ELISA (IL-6, IL-1β, and CXCL2), and Western blot or immunostaining (CEBP, STAT3, NUPR1, and IGF1) showed strong correlation with transcriptome data. Since TLR2 plays an important role in SA endophthalmitis, counter regulation analysis of TLR2 ligand pretreated retina or the use of retinas from TLR2 knockout mice showed the down-regulation of inflammatory regulatory genes. Collectively, our study provides, for the first time, a comprehensive analysis of the transcriptomic response and identifies key pathways regulating retinal innate responses in staphylococcal endophthalmitis. PMID:26865111

  17. Saporin as a novel suicide gene in anticancer gene therapy.

    PubMed

    Zarovni, N; Vago, R; Soldà, T; Monaco, L; Fabbrini, M S

    2007-02-01

    We used a non-viral gene delivery approach to explore the potential of the plant saporin (SAP) gene as an alternative to the currently employed suicide genes in cancer therapy. Plasmids expressing cytosolic SAP were generated by placing the region encoding the mature plant ribosome-inactivating protein under the control of cytomegalovirus (CMV) or simian virus 40 (SV40) promoters. Their ability to inhibit protein synthesis was first tested in cultured tumor cells co-transfected with a luciferase reporter gene. In particular, SAP expression driven by CMV promoter (pCI-SAP) demonstrated that only 10 ng of plasmid per 1.6 x 10(4) B16 cells drastically reduced luciferase activity to 18% of that in control cells. Direct intratumoral injection of pCI-SAP complexed with either lipofectamine or N-(2,3-dioleoyloxy-1-propyl) trimethylammonium methyl sulfate (DOTAP) in B16 melanoma-bearing mice resulted in a noteworthy attenuation of tumor growth. This antitumor effect was increased in mice that received repeated intratumoral injections. A SAP catalytic inactive mutant (SAP-KQ) failed to exert any antitumor effect demonstrating that this was specifically owing to the SAP N-glycosidase activity. Our overall data strongly suggest that the gene encoding SAP, owing to its rapid and effective action and its independence from the proliferative state of target cells might become a suitable candidate suicide gene for oncologic applications. PMID:17008932

  18. A Comparative Study of Retinal Function in Rabbits after Panretinal Selective Retina Therapy versus Conventional Panretinal Photocoagulation

    PubMed Central

    Park, Young Gun; Kang, Seungbum; Brinkmann, Ralf; Roh, Young-Jung

    2015-01-01

    Purpose. This study evaluates functional changes in electroretinographic findings after selective retina therapy (SRT) compared to panretinal photocoagulation (PRP) in rabbits. Methods. The right eyes of 12 Chinchilla rabbits received 200 laser treatment spots. The right eyes of six rabbits received SRT (SRT group), whereas the other six animals were treated using PRP on the right eye (PRP group). The eyes were investigated using full-field ERG 1 hour and 3 weeks after treatment. Histologic exam to assess the tissue response of lasers was performed on 3 weeks. Results. No significant changes in the mean ROD or CR b-wave amplitudes of the SRT lesions were evident, compared to baseline, 1 h after laser treatment (p = 0.372 and 0.278, resp.). In addition, the OPs and 30 Hz flickers of the SRT lesions were not significantly altered (p = 0.17 and 0.243, resp.). At 3 weeks, similar results were found. Comparing the two groups, the ROD b-wave amplitude was reduced in the PRP and SRT groups to 60.04 ± 4.2% and 92.32 ± 6.43% of baseline (p < 0.001). Histologically, there was no visible photoreceptor alterations on week 3. Conclusions. SRT in rabbit eyes induced less functional loss than PRP in both rod-mediated retinal function and cone-mediated retinal function. In addition, SRT irradiated eyes had no functional loss compared to its control. PMID:26525905

  19. Reprogramming of adult rod photoreceptors prevents retinal degeneration

    PubMed Central

    Montana, Cynthia L.; Kolesnikov, Alexander V.; Shen, Susan Q.; Myers, Connie A.; Kefalov, Vladimir J.; Corbo, Joseph C.

    2013-01-01

    A prime goal of regenerative medicine is to direct cell fates in a therapeutically useful manner. Retinitis pigmentosa is one of the most common degenerative diseases of the eye and is associated with early rod photoreceptor death followed by secondary cone degeneration. We hypothesized that converting adult rods into cones, via knockdown of the rod photoreceptor determinant Nrl, could make the cells resistant to the effects of mutations in rod-specific genes, thereby preventing secondary cone loss. To test this idea, we engineered a tamoxifen-inducible allele of Nrl to acutely inactivate the gene in adult rods. This manipulation resulted in reprogramming of rods into cells with a variety of cone-like molecular, histologic, and functional properties. Moreover, reprogramming of adult rods achieved cellular and functional rescue of retinal degeneration in a mouse model of retinitis pigmentosa. These findings suggest that elimination of Nrl in adult rods may represent a unique therapy for retinal degeneration. PMID:23319618

  20. The Muscular Dystrophies: From Genes to Therapies

    PubMed Central

    Porter, Neil C; Bloch, Robert J

    2015-01-01

    The genetic basis of many muscular disorders, including many of the more common muscular dystrophies, is now known. Clinically, the recent genetic advances have improved diagnostic capabilities, but they have not yet provided clues about treatment or management. Thanks to better management strategies and therapeutic interventions, however, many patients with a muscular dystrophy are more active and are living longer. Physical therapists, therefore, are more likely to see a patient with a muscular dystrophy, so understanding these muscle disorders and their management is essential. Physical therapy offers the most promise in caring for the majority of patients with these conditions, because it is unlikely that advances in gene therapy will significantly alter their clinical treatment in the near future. This perspective covers some of the basic molecular biological advances together with the clinical manifestations of the muscular dystrophies and the latest approaches to their management. PMID:16305275

  1. Successful Gene Therapy in the RPGRIP1-deficient Dog: a Large Model of Cone–Rod Dystrophy

    PubMed Central

    Lhériteau, Elsa; Petit, Lolita; Weber, Michel; Le Meur, Guylène; Deschamps, Jack-Yves; Libeau, Lyse; Mendes-Madeira, Alexandra; Guihal, Caroline; François, Achille; Guyon, Richard; Provost, Nathalie; Lemoine, Françoise; Papal, Samantha; El-Amraoui, Aziz; Colle, Marie-Anne; Moullier, Philippe; Rolling, Fabienne

    2014-01-01

    For the development of new therapies, proof-of-concept studies in large animal models that share clinical features with their human counterparts represent a pivotal step. For inherited retinal dystrophies primarily involving photoreceptor cells, the efficacy of gene therapy has been demonstrated in canine models of stationary cone dystrophies and progressive rod–cone dystrophies but not in large models of progressive cone–rod dystrophies, another important cause of blindness. To address the last issue, we evaluated gene therapy in the retinitis pigmentosa GTPase regulator interacting protein 1 (RPGRIP1)-deficient dog, a model exhibiting a severe cone–rod dystrophy similar to that seen in humans. Subretinal injection of AAV5 (n = 5) or AAV8 (n = 2) encoding the canine Rpgrip1 improved photoreceptor survival in transduced areas of treated retinas. Cone function was significantly and stably rescued in all treated eyes (18–72% of those recorded in normal eyes) up to 24 months postinjection. Rod function was also preserved (22–29% of baseline function) in four of the five treated dogs up to 24 months postinjection. No detectable rod function remained in untreated contralateral eyes. More importantly, treatment preserved bright- and dim-light vision. Efficacy of gene therapy in this large animal model of cone–rod dystrophy provides great promise for human treatment. PMID:24091916

  2. Successful gene therapy in the RPGRIP1-deficient dog: a large model of cone-rod dystrophy.

    PubMed

    Lhériteau, Elsa; Petit, Lolita; Weber, Michel; Le Meur, Guylène; Deschamps, Jack-Yves; Libeau, Lyse; Mendes-Madeira, Alexandra; Guihal, Caroline; François, Achille; Guyon, Richard; Provost, Nathalie; Lemoine, Françoise; Papal, Samantha; El-Amraoui, Aziz; Colle, Marie-Anne; Moullier, Philippe; Rolling, Fabienne

    2014-02-01

    For the development of new therapies, proof-of-concept studies in large animal models that share clinical features with their human counterparts represent a pivotal step. For inherited retinal dystrophies primarily involving photoreceptor cells, the efficacy of gene therapy has been demonstrated in canine models of stationary cone dystrophies and progressive rod-cone dystrophies but not in large models of progressive cone-rod dystrophies, another important cause of blindness. To address the last issue, we evaluated gene therapy in the retinitis pigmentosa GTPase regulator interacting protein 1 (RPGRIP1)-deficient dog, a model exhibiting a severe cone-rod dystrophy similar to that seen in humans. Subretinal injection of AAV5 (n = 5) or AAV8 (n = 2) encoding the canine Rpgrip1 improved photoreceptor survival in transduced areas of treated retinas. Cone function was significantly and stably rescued in all treated eyes (18-72% of those recorded in normal eyes) up to 24 months postinjection. Rod function was also preserved (22-29% of baseline function) in four of the five treated dogs up to 24 months postinjection. No detectable rod function remained in untreated contralateral eyes. More importantly, treatment preserved bright- and dim-light vision. Efficacy of gene therapy in this large animal model of cone-rod dystrophy provides great promise for human treatment. PMID:24091916

  3. Efficient In Silico Identification of a Common Insertion in the MAK Gene which Causes Retinitis Pigmentosa

    PubMed Central

    Bujakowska, Kinga M.; White, Joseph; Place, Emily; Consugar, Mark; Comander, Jason

    2015-01-01

    Background Next generation sequencing (NGS) offers a rapid and comprehensive method of screening for mutations associated with retinitis pigmentosa and related disorders. However, certain sequence alterations such as large insertions or deletions may remain undetected using standard NGS pipelines. One such mutation is a recently-identified Alu insertion into the Male Germ Cell-Associated Kinase (MAK) gene, which is missed by standard NGS-based variant callers. Here, we developed an in silico method of searching NGS raw sequence reads to detect this mutation, without the need to recalculate sequence alignments or to screen every sample by PCR. Methods The Linux program grep was used to search for a 23 bp “probe” sequence containing the known junction sequence of the insert. A corresponding search was performed with the wildtype sequence. The matching reads were counted and further compared to the known sequences of the full wildtype and mutant genomic loci. (See https://github.com/MEEIBioinformaticsCenter/grepsearch.) Results In a test sample set consisting of eleven previously published homozygous mutants, detection of the MAK-Alu insertion was validated with 100% sensitivity and specificity. As a discovery cohort, raw NGS reads from 1,847 samples (including custom and whole exome selective capture) were searched in ~1 hour on a local computer cluster, yielding an additional five samples with MAK-Alu insertions and solving two previously unsolved pedigrees. Of these, one patient was homozygous for the insertion, one compound heterozygous with a missense change on the other allele (c. 46G>A; p.Gly16Arg), and three were heterozygous carriers. Conclusions Using the MAK-Alu grep program proved to be a rapid and effective method of finding a known, disease-causing Alu insertion in a large cohort of patients with NGS data. This simple approach avoids wet-lab assays or computationally expensive algorithms, and could also be used for other known disease

  4. Progressive outer retinal necrosis-like retinitis in immunocompetent hosts.

    PubMed

    Chawla, Rohan; Tripathy, Koushik; Gogia, Varun; Venkatesh, Pradeep

    2016-01-01

    We describe two young immunocompetent women presenting with bilateral retinitis with outer retinal necrosis involving posterior pole with centrifugal spread and multifocal lesions simulating progressive outer retinal necrosis (PORN) like retinitis. Serology was negative for HIV and CD4 counts were normal; however, both women were on oral steroids at presentation for suspected autoimmune chorioretinitis. The retinitis in both eyes responded well to oral valaciclovir therapy. However, the eye with the more fulminant involvement developed retinal detachment with a loss of vision. Retinal atrophy was seen in the less involved eye with preservation of vision. Through these cases, we aim to describe a unique evolution of PORN-like retinitis in immunocompetent women, which was probably aggravated by a short-term immunosuppression secondary to oral steroids. PMID:27511757

  5. Cell Targeting in Anti-Cancer Gene Therapy

    PubMed Central

    Lila, Mohd Azmi Mohd; Siew, John Shia Kwong; Zakaria, Hayati; Saad, Suria Mohd; Ni, Lim Shen; Abdullah, Jafri Malin

    2004-01-01

    Gene therapy is a promising approach towards cancer treatment. The main aim of the therapy is to destroy cancer cells, usually by apoptotic mechanisms, and preserving others. However, its application has been hindered by many factors including poor cellular uptake, non-specific cell targeting and undesirable interferences with other genes or gene products. A variety of strategies exist to improve cellular uptake efficiency of gene-based therapies. This paper highlights advancements in gene therapy research and its application in relation to anti-cancer treatment. PMID:22977356

  6. Cyclic AMP-dependent activation of rhodopsin gene transcription in cultured retinal precursor cells of chicken embryo.

    PubMed

    Voisin, Pierre; Bernard, Marianne

    2009-07-01

    The present study describes a robust 50-fold increase in rhodopsin gene transcription by cAMP in cultured retinal precursor cells of chicken embryo. Retinal cells isolated at embryonic day 8 (E8) and cultured for 3 days in serum-supplemented medium differentiated mostly into red-sensitive cones and to a lesser degree into green-sensitive cones, as indicated by real-time RT-PCR quantification of each specific opsin mRNA. In contrast, both rhodopsin mRNA concentration and rhodopsin gene promoter activity required the presence of cAMP-increasing agents [forskolin and 3-isobutyl-1-methylxanthine (IBMX)] to reach significant levels. This response was rod-specific and was sufficient to activate rhodopsin gene transcription in serum-free medium. The increase in rhodopsin mRNA levels evoked by a series of cAMP analogs suggested the response was mediated by protein kinase A, not by EPAC. Membrane depolarization by high KCl concentration also increased rhodopsin mRNA levels and this response was strongly potentiated by IBMX. The rhodopsin gene response to cAMP-increasing agents was developmentally gated between E6 and E7. Rod-specific transducin alpha subunit mRNA levels also increased up to 50-fold in response to forskolin and IBMX, while rod-specific phosphodiesterase-VI and rod arrestin transcripts increased 3- to 10-fold. These results suggest a cAMP-mediated signaling pathway may play a role in rod differentiation. PMID:19457115

  7. Gene therapy: Into the home stretch

    SciTech Connect

    Culliton, B.J.

    1990-08-31

    Tumors cannot live without blood. Shut off the blood vessels that feed a tumor and the tumor will turn black and shrivel away. That simple idea lies behind the first attempt to cure a disease by gene therapy, expected to take place at the National Cancer Institute in the next few weeks. When it does, it will test a technique that worked like a charm in mice. When a potent natural killer called tumor necrosis factor, or TNF, is injected into the bloodstream of mice, it begins to shrink tumors within hours, sometimes even minutes. But so far, attempts to recreate that miracle in people with cancer have not fared as well. TNF has been given intravenously to more than 35 patients in experiments that were a failure. Researchers hope to deliver TNF in much larger doses directly to a tumor by packaging the gene for TNF inside special lymphocytes that have a natural affinity for cancer.

  8. Microphthalmia-associated transcription factor regulates the visual cycle genes Rlbp1 and Rdh5 in the retinal pigment epithelium

    PubMed Central

    Wen, Bin; Li, Shuang; Li, Huirong; Chen, Yu; Ma, Xiaoyin; Wang, Jing; Lu, Fan; Qu, Jia; Hou, Ling

    2016-01-01

    Regeneration of the visual pigment by cells of the retinal pigment epithelium (RPE) is fundamental to vision. Here we show that the microphthalmia-associated transcription factor, MITF, which plays a central role in the development and function of RPE cells, regulates the expression of two visual cycle genes, Rlbp1 which encodes retinaldehyde binding protein-1 (RLBP1), and Rdh5, which encodes retinol dehydrogenase-5 (RDH5). First, we found that Rlbp1 and Rdh5 are downregulated in optic cups and presumptive RPEs of Mitf-deficient mouse embryos. Second, experimental manipulation of MITF levels in human RPE cells in culture leads to corresponding modulations of the endogenous levels of RLBP1 and RDH5. Third, the retinal degeneration associated with the disruption of the visual cycle in Mitf-deficient mice can be partially corrected both structurally and functionally by an exogenous supply of 9-cis-retinal. We conclude that the expression of Rlbp1 and Rdh5 critically depends on functional Mitf in the RPE and suggest that MITF has an important role in controlling retinoid processing in the RPE. PMID:26876013

  9. Cytomegalovirus retinitis

    MedlinePlus

    ... to prevent its return. Alternative Names Cytomegalovirus retinitis Images Eye CMV retinitis CMV (cytomegalovirus) References Crumpacker CS. ... 5. Read More Antibody HIV/AIDS Immune response Retinal detachment Systemic WBC count Update Date 12/10/ ...

  10. Glucagon-Like Peptide-1 Gene Therapy

    PubMed Central

    Rowzee, Anne M.; Cawley, Niamh X.; Chiorini, John A.; Di Pasquale, Giovanni

    2011-01-01

    Glucagon-like peptide 1 (GLP-1) is a small peptide component of the prohormone, proglucagon, that is produced in the gut. Exendin-4, a GLP-1 receptor agonist originally isolated from the saliva of H. suspectum or Gila monster, is a peptide that shares sequence and functional homology with GLP-1. Both peptides have been demonstrated to stimulate insulin secretion, inhibit glucagon secretion, promote satiety and slow gastric emptying. As such, GLP-1 and Exendin-4 have become attractive pharmaceutical targets as an adjunctive therapy for individuals with type II diabetes mellitus, with several products currently available clinically. Herein we summarize the cell biology leading to GLP-1 production and secretion from intestinal L-cells and the endocrine functions of this peptide and Exendin-4 in humans. Additionally, gene therapeutic applications of GLP-1 and Exendin-4 are discussed with a focus on recent work using the salivary gland as a gene therapy target organ for the treatment of diabetes mellitus. PMID:21747830

  11. Gene Therapy May Offer Hope for 'Bubble Boy' Disease

    MedlinePlus

    ... html Gene Therapy May Offer Hope for 'Bubble Boy' Disease Preliminary research tries new approach to rebuild ... therapy shows preliminary promise against so-called "Bubble Boy" disease, researchers report. A small, early-stage trial ...

  12. Identification of an Alternative Splicing Product of the Otx2 Gene Expressed in the Neural Retina and Retinal Pigmented Epithelial Cells

    PubMed Central

    Kole, Christo; Berdugo, Naomi; Da Silva, Corinne; Aït-Ali, Najate; Millet-Puel, Géraldine; Pagan, Delphine; Blond, Frédéric; Poidevin, Laetitia; Ripp, Raymond; Fontaine, Valérie; Wincker, Patrick; Zack, Donald J.; Sahel, José-Alain; Poch, Olivier; Léveillard, Thierry

    2016-01-01

    To investigate the complexity of alternative splicing in the retina, we sequenced and analyzed a total of 115,706 clones from normalized cDNA libraries from mouse neural retina (66,217) and rat retinal pigmented epithelium (49,489). Based upon clustering the cDNAs and mapping them with their respective genomes, the estimated numbers of genes were 9,134 for the mouse neural retina and 12,050 for the rat retinal pigmented epithelium libraries. This unique collection of retinal of messenger RNAs is maintained and accessible through a web-base server to the whole community of retinal biologists for further functional characterization. The analysis revealed 3,248 and 3,202 alternative splice events for mouse neural retina and rat retinal pigmented epithelium, respectively. We focused on transcription factors involved in vision. Among the six candidates suitable for functional analysis, we selected Otx2S, a novel variant of the Otx2 gene with a deletion within the homeodomain sequence. Otx2S is expressed in both the neural retina and retinal pigmented epithelium, and encodes a protein that is targeted to the nucleus. OTX2S exerts transdominant activity on the tyrosinase promoter when tested in the physiological environment of primary RPE cells. By overexpressing OTX2S in primary RPE cells using an adeno associated viral vector, we identified 10 genes whose expression is positively regulated by OTX2S. We find that OTX2S is able to bind to the chromatin at the promoter of the retinal dehydrogenase 10 (RDH10) gene. PMID:26985665

  13. Identification of an Alternative Splicing Product of the Otx2 Gene Expressed in the Neural Retina and Retinal Pigmented Epithelial Cells.

    PubMed

    Kole, Christo; Berdugo, Naomi; Da Silva, Corinne; Aït-Ali, Najate; Millet-Puel, Géraldine; Pagan, Delphine; Blond, Frédéric; Poidevin, Laetitia; Ripp, Raymond; Fontaine, Valérie; Wincker, Patrick; Zack, Donald J; Sahel, José-Alain; Poch, Olivier; Léveillard, Thierry

    2016-01-01

    To investigate the complexity of alternative splicing in the retina, we sequenced and analyzed a total of 115,706 clones from normalized cDNA libraries from mouse neural retina (66,217) and rat retinal pigmented epithelium (49,489). Based upon clustering the cDNAs and mapping them with their respective genomes, the estimated numbers of genes were 9,134 for the mouse neural retina and 12,050 for the rat retinal pigmented epithelium libraries. This unique collection of retinal of messenger RNAs is maintained and accessible through a web-base server to the whole community of retinal biologists for further functional characterization. The analysis revealed 3,248 and 3,202 alternative splice events for mouse neural retina and rat retinal pigmented epithelium, respectively. We focused on transcription factors involved in vision. Among the six candidates suitable for functional analysis, we selected Otx2S, a novel variant of the Otx2 gene with a deletion within the homeodomain sequence. Otx2S is expressed in both the neural retina and retinal pigmented epithelium, and encodes a protein that is targeted to the nucleus. OTX2S exerts transdominant activity on the tyrosinase promoter when tested in the physiological environment of primary RPE cells. By overexpressing OTX2S in primary RPE cells using an adeno associated viral vector, we identified 10 genes whose expression is positively regulated by OTX2S. We find that OTX2S is able to bind to the chromatin at the promoter of the retinal dehydrogenase 10 (RDH10) gene. PMID:26985665

  14. Gene expression regulation in retinal pigment epithelial cells induced by viral RNA and viral/bacterial DNA

    PubMed Central

    Brosig, Anton; Kuhrt, Heidrun; Wiedemann, Peter; Kohen, Leon; Bringmann, Andreas

    2015-01-01

    Purpose The pathogenesis of age-related macular degeneration (AMD) is associated with systemic and local inflammation. Various studies suggested that viral or bacterial infection may aggravate retinal inflammation in the aged retina. We compared the effects of synthetic viral RNA (poly(I:C)) and viral/bacterial DNA (CpG-ODN) on the expression of genes known to be involved in the development of AMD in retinal pigment epithelial (RPE) cells. Methods Cultured human RPE cells were stimulated with poly(I:C; 500 µg/ml) or CpG-ODN (500 nM). Alterations in gene expression and protein secretion were determined with real-time RT–PCR and ELISA, respectively. Phosphorylation of signal transduction molecules was revealed by western blotting. Results Poly(I:C) induced gene expression of the pattern recognition receptor TLR3, transcription factors (HIF-1α, p65/NF-κB), the angiogenic factor bFGF, inflammatory factors (IL-1β, IL-6, TNFα, MCP-1, MIP-2), and complement factors (C5, C9, CFB). Poly(I:C) also induced phosphorylation of ERK1/2 and p38 MAPK proteins, and the secretion of bFGF and TNFα from the cells. CpG-ODN induced moderate gene expression of transcription factors (p65/NF-κB, NFAT5) and complement factors (C5, C9), while it had no effect on the expression of various TLR, angiogenic factor, and inflammatory factor genes. The activities of various signal transduction pathways and transcription factors were differentially involved in mediating the poly(I:C)-induced transcriptional activation of distinct genes. Conclusions The widespread effects of viral RNA, and the restricted effects of viral/bacterial DNA, on the gene expression pattern of RPE cells may suggest that viral RNA rather than viral/bacterial DNA induces physiologic alterations of RPE cells, which may aggravate inflammation in the aged retina. The data also suggest that selective inhibition of distinct signal transduction pathways or individual transcription factors may not be effective to inhibit

  15. Lentiviral Vectors and Cystic Fibrosis Gene Therapy

    PubMed Central

    Castellani, Stefano; Conese, Massimo

    2010-01-01

    Cystic fibrosis (CF) is a chronic autosomic recessive syndrome, caused by mutations in the CF Transmembrane Conductance Regulator (CFTR) gene, a chloride channel expressed on the apical side of the airway epithelial cells. The lack of CFTR activity brings a dysregulated exchange of ions and water through the airway epithelium, one of the main aspects of CF lung disease pathophysiology. Lentiviral (LV) vectors, of the Retroviridae family, show interesting properties for CF gene therapy, since they integrate into the host genome and allow long-lasting gene expression. Proof-of-principle that LV vectors can transduce the airway epithelium and correct the basic electrophysiological defect in CF mice has been given. Initial data also demonstrate that LV vectors can be repeatedly administered to the lung and do not give rise to a gross inflammatory process, although they can elicit a T cell-mediated response to the transgene. Future studies will clarify the efficacy and safety profile of LV vectors in new complex animal models with CF, such as ferrets and pigs. PMID:21994643

  16. Targeting iron-mediated retinal degeneration by local delivery of transferrin.

    PubMed

    Picard, Emilie; Le Rouzic, Quentin; Oudar, Antonin; Berdugo, Marianne; El Sanharawi, Mohamed; Andrieu-Soler, Charlotte; Naud, Marie-Christine; Jonet, Laurent; Latour, Chloé; Klein, Christophe; Galiacy, Stéphane; Malecaze, François; Coppin, Hélène; Roth, Marie-Paule; Jeanny, Jean-Claude; Courtois, Yves; Behar-Cohen, Francine

    2015-12-01

    Iron is essential for retinal function but contributes to oxidative stress-mediated degeneration. Iron retinal homeostasis is highly regulated and transferrin (Tf), a potent iron chelator, is endogenously secreted by retinal cells. In this study, therapeutic potential of a local Tf delivery was evaluated in animal models of retinal degeneration. After intravitreal injection, Tf spread rapidly within the retina and accumulated in photoreceptors and retinal pigment epithelium, before reaching the blood circulation. Tf injected in the vitreous prior and, to a lesser extent, after light-induced retinal degeneration, efficiently protected the retina histology and function. We found an association between Tf treatment and the modulation of iron homeostasis resulting in a decrease of iron content and oxidative stress marker. The immunomodulation function of Tf could be seen through a reduction in macrophage/microglial activation as well as modulated inflammation responses. In a mouse model of hemochromatosis, Tf had the capacity to clear abnormal iron accumulation from retinas. And in the slow P23H rat model of retinal degeneration, a sustained release of Tf in the vitreous via non-viral gene therapy efficently slowed-down the photoreceptors death and preserved their function. These results clearly demonstrate the synergistic neuroprotective roles of Tf against retinal degeneration and allow identify Tf as an innovative and not toxic therapy for retinal diseases associated with oxidative stress. PMID:26454080

  17. Structural recovery of the retina in a retinoschisin-deficient mouse after gene replacement therapy by solid lipid nanoparticles.

    PubMed

    Apaolaza, P S; Del Pozo-Rodríguez, A; Solinís, M A; Rodríguez, J M; Friedrich, U; Torrecilla, J; Weber, B H F; Rodríguez-Gascón, A

    2016-06-01

    X-linked juvenile retinoschisis (XLRS) is a retinal degenerative disorder caused by mutations in the RS1 gene encoding a protein termed retinoschisin. The disease is an excellent candidate for gene replacement therapy as the majority of mutations have been shown to lead to a complete deficiency of the secreted protein in the retinal structures. In this work, we have studied the ability of non-viral vectors based on solid lipid nanoparticles (SLN) to induce the expression of retinoschisin in photoreceptors (PR) after intravitreal administration to Rs1h-deficient mice. We designed two vectors prepared with SLN, protamine, and dextran (DX) or hyaluronic acid (HA), bearing a plasmid containing the human RS1 gene under the control of the murin opsin promoter (mOPS). In vitro, the nanocarriers were able to induce the expression of retinoschisin in a PR cell line. After injection into the murine vitreous, the formulation prepared with HA induced a higher transfection level in PR than the formulation prepared with DX. Moreover, the level of retinoschisin in the inner nuclear layer (INL), where bipolar cells are located, was also higher. Two weeks after vitreal administration into Rs1h-deficient mice, both formulations showed significant improvement of the retinal structure by inducing a decrease of cavities and PR loss, and an increase of retinal and outer nuclear layer (ONL) thickness. HA-SLN resulted in a significant higher increase in the thickness of both retina and ONL, which can be explained by the higher transfection level of PR. In conclusion, we have shown the structural improvement of the retina of Rs1h-deficient mice with PR specific expression of the RS1 gene driven by the specific promoter mOPS, after successful delivery via SLN-based non-viral vectors. PMID:26986855

  18. Cellular responses following retinal injuries and therapeutic approaches for neurodegenerative diseases.

    PubMed

    Cuenca, Nicolás; Fernández-Sánchez, Laura; Campello, Laura; Maneu, Victoria; De la Villa, Pedro; Lax, Pedro; Pinilla, Isabel

    2014-11-01

    Retinal neurodegenerative diseases like age-related macular degeneration, glaucoma, diabetic retinopathy and retinitis pigmentosa each have a different etiology and pathogenesis. However, at the cellular and molecular level, the response to retinal injury is similar in all of them, and results in morphological and functional impairment of retinal cells. This retinal degeneration may be triggered by gene defects, increased intraocular pressure, high levels of blood glucose, other types of stress or aging, but they all frequently induce a set of cell signals that lead to well-established and similar morphological and functional changes, including controlled cell death and retinal remodeling. Interestingly, an inflammatory response, oxidative stress and activation of apoptotic pathways are common features in all these diseases. Furthermore, it is important to note the relevant role of glial cells, including astrocytes, Müller cells and microglia, because their response to injury is decisive for maintaining the health of the retina or its degeneration. Several therapeutic approaches have been developed to preserve retinal function or restore eyesight in pathological conditions. In this context, neuroprotective compounds, gene therapy, cell transplantation or artificial devices should be applied at the appropriate stage of retinal degeneration to obtain successful results. This review provides an overview of the common and distinctive features of retinal neurodegenerative diseases, including the molecular, anatomical and functional changes caused by the cellular response to damage, in order to establish appropriate treatments for these pathologies. PMID:25038518

  19. Gene and Stem Cell Therapy: Alone or in Combination?

    PubMed Central

    Rafi, Mohammad A.

    2011-01-01

    Introduction Both gene and stem cell therapies hold great promise in the treatment of many genetic diseases and are currently focus of interest for many investigators. While both approaches are offering great and valuable treatment options for devastating and life-threatening diseases, they hold much greater promise in combination. Methods As there are multiple options in selecting gene transfer vehicles among the non-viral and viral vectors, there are also many options among the different transplantable cell types ranging from lineage-restricted progenitor cells to multipotent and pluripotent stem cells. Here, combination of the gene therapy and stem cell therapy is discussed. Results Several suc-cessful gene and stem cell therapies have been reported both in animal and human trials. Combination of the gene therapy and stem cell therapy can be carried out sequentially where the cell transplantation and the in vivo gene therapy are accomplished one after the other; or, as it is more commonly practiced, they can be carried out as ex vivo gene therapy where the transplantable cells are genetically modified outside the body before being transplanted into the body. Conclusion The combination of the stem-cell technology with gene therapy has the potential of providing both regenerative tissue and therapeutic material simultaneously; therefore, having the benefits of both technologies. PMID:23678430

  20. Inner Limiting Membrane Barriers to AAV-mediated Retinal Transduction From the Vitreous

    PubMed Central

    Dalkara, Deniz; Kolstad, Kathleen D; Caporale, Natalia; Visel, Meike; Klimczak, Ryan R; Schaffer, David V; Flannery, John G

    2009-01-01

    Adeno-associated viral gene therapy has shown great promise in treating retinal disorders, with three promising clinical trials in progress. Numerous adeno-associated virus (AAV) serotypes can infect various cells of the retina when administered subretinally, but the retinal detachment accompanying this injection induces changes that negatively impact the microenvironment and survival of retinal neurons. Intravitreal administration could circumvent this problem, but only AAV2 can infect retinal cells from the vitreous, and transduction is limited to the inner retina. We therefore sought to investigate and reduce barriers to transduction from the vitreous. We fluorescently labeled several AAV serotype capsids and followed their retinal distribution after intravitreal injection. AAV2, 8, and 9 accumulate at the vitreoretinal junction. AAV1 and 5 show no accumulation, indicating a lack of appropriate receptors at the inner limiting membrane (ILM). Importantly, mild digestion of the ILM with a nonspecific protease enabled substantially enhanced transduction of multiple retinal cell types from the vitreous, with AAV5 mediating particularly remarkable expression in all retinal layers. This protease treatment has no effect on retinal function as shown by electroretinogram (ERG) and visual cortex cell population responses. These findings may help avoid limitations, risks, and damage associated with subretinal injections currently necessary for clinical gene therapy. PMID:19672248

  1. Genetically engineering adenoviral vectors for gene therapy.

    PubMed

    Coughlan, Lynda

    2014-01-01

    Adenoviral (Ad) vectors are commonly used for various gene therapy applications. Significant advances in the genetic engineering of Ad vectors in recent years has highlighted their potential for the treatment of metastatic disease. There are several methods to genetically modify the Ad genome to incorporate retargeting peptides which will redirect the natural tropism of the viruses, including homologous recombination in bacteria or yeast. However, homologous recombination in yeast is highly efficient and can be achieved without the need for extensive cloning strategies. In addition, the method does not rely on the presence of unique restriction sites within the Ad genome and the reagents required for this method are widely available and inexpensive. Large plasmids containing the entire adenoviral genome (~36 kbp) can be modified within Saccharomyces cerevisiae yeast and genomes easily rescued in Escherichia coli hosts for analysis or amplification. A method for two-step homologous recombination in yeast is described in this chapter. PMID:24243238

  2. Engineering AAV receptor footprints for gene therapy.

    PubMed

    Madigan, Victoria J; Asokan, Aravind

    2016-06-01

    Adeno-associated viruses (AAV) are currently at the forefront of human gene therapy clinical trials as recombinant vectors. Significant progress has been made in elucidating the structure, biology and tropisms of different naturally occurring AAV isolates in the past decade. In particular, a spectrum of AAV capsid interactions with host receptors have been identified and characterized. These studies have enabled a better understanding of key determinants of AAV cell recognition and entry in different hosts. This knowledge is now being applied toward engineering new, lab-derived AAV capsids with favorable transduction profiles. The current review conveys a structural perspective of capsid-glycan interactions and provides a roadmap for generating synthetic strains by engineering AAV receptor footprints. PMID:27262111

  3. [Therapeutical effect of growth-associated protein 43 (GAP43) gene-modified bone marrow mesenchymal stem cell transplantation on rat retinal degenerative diseases].

    PubMed

    Yang, Juan; Xie, Maosong; Zheng, Weidong; Hu, Jianzhang; Qu, Qiang

    2016-08-01

    Objective To investigate the potential of the treatment of growth-associated protein 43 (GAP43) gene-modified bone marrow-derived mesenchymal stem cells (BMSCs) for retinitis pigmentosa (RP). Methods BMSCs were isolated and cultured by adherence method. By transfecting GAP43 gene into BMSCs via a lentivirus vector, we got GAP43 gene-modified BMSCs. Sixty-three Royal College of Surgeons (RCS) rats were randomly divided into three groups: experimental group, negative control group and blank control group. The experimental rats received subretinal injection of GAP43 gene-modified BMSCs. The negative control rats received subretinal injection of BMSCs. The control rats received subretinal injection of PBS. Thirty days after transplanting, the retinal thickness was detected by optical coherence tomography (OCT), and the expression of rhodopsin in RCS rat retinas was examined by Western blotting. Results Compared with the blank control group and the negative control group, 30 days after GAP43 gene-modified BMSC transplantation, the retinal thickness of the experimental group remarkably increased and the expression of rhodopsin significantly rose. Conclusion GAP43 gene-modified BMSC transplantation can increase survival photoreceptor cells and delay retinal degeneration. PMID:27412933

  4. Mutations in the pre-mRNA splicing factor gene PRPC8 in autosomal dominant retinitis pigmentosa (RP13).

    PubMed

    McKie, A B; McHale, J C; Keen, T J; Tarttelin, E E; Goliath, R; van Lith-Verhoeven, J J; Greenberg, J; Ramesar, R S; Hoyng, C B; Cremers, F P; Mackey, D A; Bhattacharya, S S; Bird, A C; Markham, A F; Inglehearn, C F

    2001-07-15

    Retinitis pigmentosa (RP) is a genetically heterogeneous disorder characterized by progressive degeneration of the peripheral retina leading to night blindness and loss of visual fields. With an incidence of approximately 1 in 4000, RP can be inherited in X-linked, autosomal dominant or autosomal recessive modes. The RP13 locus for autosomal dominant RP (adRP) was placed on chromosome 17p13.3 by linkage mapping in a large South African adRP family. Using a positional cloning and candidate gene strategy, we have identified seven different missense mutations in the splicing factor gene PRPC8 in adRP families. Three of the mutations cosegregate within three RP13 linked families including the original large South African pedigree, and four additional mutations have been identified in other unrelated adRP families. The seven mutations are clustered within a 14 codon stretch within the last exon of this large 7 kb transcript. The altered amino acid residues at the C-terminus exhibit a high degree of conservation across species as diverse as humans, Arabidopsis and trypanosome, suggesting that some functional significance is associated with this part of the protein. These mutations in this ubiquitous and highly conserved splicing factor offer compelling evidence for a novel pathway to retinal degeneration. PMID:11468273

  5. Virotherapy: cancer gene therapy at last?

    PubMed Central

    Bilsland, Alan E.; Spiliopoulou, Pavlina; Evans, T. R. Jeffry

    2016-01-01

    For decades, effective cancer gene therapy has been a tantalising prospect; for a therapeutic modality potentially able to elicit highly effective and selective responses, definitive efficacy outcomes have often seemed out of reach. However, steady progress in vector development and accumulated experience from previous clinical studies has finally led the field to its first licensed therapy. Following a pivotal phase III trial, Imlygic (talimogene laherparepvec/T-Vec) received US approval as a treatment for cutaneous and subcutaneous melanoma in October 2015, followed several weeks later by its European authorisation. These represent the first approvals for an oncolytic virotherapy. Imlygic is an advanced-generation herpesvirus-based vector optimised for oncolytic and immunomodulatory activities. Many other oncolytic agents currently remain in development, providing hope that current success will be followed by other diverse vectors that may ultimately come to constitute a new class of clinical anti-cancer agents. In this review, we discuss some of the key oncolytic viral agents developed in the adenovirus and herpesvirus classes, and the prospects for further enhancing their efficacy by combining them with novel immunotherapeutic approaches.

  6. [Acute retinal necrosis].

    PubMed

    Lucke, K; Reinking, U; el-Hifnawi, E; Dennin, R H; Laqua, H

    1988-12-01

    The authors report on three patients with acute retinal necrosis who were treated with the virostatic agent Acyclovir and who underwent vitreoretinal surgery with silicone oil filling for total retinal detachment. In two eyes the retina was reattached, but useful vision was only preserved in one patient. Titers from blood and the vitreous, as well as microscopic findings in retinal biopsies, support the view that the necrosis is caused by a herpes simplex virus infection. After therapy with Acyclovir was instituted no further progression on the necrosis was observed. However, the development of retinal detachment could not be prevented. Early diagnosis and antiviral therapy are essential to improve the otherwise poor prognosis in this rare syndrome. PMID:3221657

  7. Autozygome-guided exome sequencing in retinal dystrophy patients reveals pathogenetic mutations and novel candidate disease genes

    PubMed Central

    Abu-Safieh, Leen; Alrashed, May; Anazi, Shamsa; Alkuraya, Hisham; Khan, Arif O.; Al-Owain, Mohammed; Al-Zahrani, Jawahir; Al-Abdi, Lama; Hashem, Mais; Al-Tarimi, Salwa; Sebai, Mohammed-Adeeb; Shamia, Ahmed; Ray-zack, Mohamed D.; Nassan, Malik; Al-Hassnan, Zuhair N.; Rahbeeni, Zuhair; Waheeb, Saad; Alkharashi, Abdullah; Abboud, Emad; Al-Hazzaa, Selwa A.F.; Alkuraya, Fowzan S.

    2013-01-01

    Retinal dystrophy (RD) is a heterogeneous group of hereditary diseases caused by loss of photoreceptor function and contributes significantly to the etiology of blindness globally but especially in the industrialized world. The extreme locus and allelic heterogeneity of these disorders poses a major diagnostic challenge and often impedes the ability to provide a molecular diagnosis that can inform counseling and gene-specific treatment strategies. In a large cohort of nearly 150 RD families, we used genomic approaches in the form of autozygome-guided mutation analysis and exome sequencing to identify the likely causative genetic lesion in the majority of cases. Additionally, our study revealed six novel candidate disease genes (C21orf2, EMC1, KIAA1549, GPR125, ACBD5, and DTHD1), two of which (ACBD5 and DTHD1) were observed in the context of syndromic forms of RD that are described for the first time. PMID:23105016

  8. Prospects for Gene Therapy in the Fragile X Syndrome

    ERIC Educational Resources Information Center

    Rattazzi, Mario C.; LaFauci, Giuseppe; Brown, W. Ted

    2004-01-01

    Gene therapy is unarguably the definitive way to treat, and possibly cure, genetic diseases. A straightforward concept in theory, in practice it has proven difficult to realize, even when directed to easily accessed somatic cell systems. Gene therapy for diseases in which the central nervous system (CNS) is the target organ presents even greater…

  9. Gene therapy in head and neck cancer: a review

    PubMed Central

    Chisholm, E; Bapat, U; Chisholm, C; Alusi, G; Vassaux, G

    2007-01-01

    Gene therapy for cancer is a rapidly evolving field with head and neck squamous cell cancer being one of the more frequently targeted cancer types. The number of clinical trials in the UK is growing and there is already a commercially available agent in China. Various gene therapy strategies along with delivery mechanisms for targeting head and neck cancer are reviewed. PMID:18057169

  10. Feedback from each retinal neuron population drives expression of subsequent fate determinant genes without influencing the cell cycle exit timing.

    PubMed

    Kei, Jeremy Ng Chi; Dudczig, Stefanie; Currie, Peter D; Jusuf, Patricia R

    2016-09-01

    During neurogenesis, progenitors balance proliferation and cell cycle exit together with expression of fate determinant genes to ensure that the correct number of each of these neuron types is generated. Although intrinsic gene expression acting cell autonomously within each progenitor drives these processes, the final number of neurons generated is also influenced by extrinsic cues, representing a potential avenue to direct neurogenesis in developmental disorders or regenerative settings without the requirement to change intrinsic gene expression. Thus, it is important to understand which of these stages of neurogenesis are amenable to such extrinsic influences. Additionally, all types of neurons are specified in a highly conserved histogenic order, although its significance is unknown. This study makes use of conserved patterns of neurogenesis in the relatively simple yet highly organized zebrafish retina model, in which such histogenic birth order is well characterized. We directly visualize and quantify birth dates and cell fate determinant expression in WT vs. environments lacking different neuronal populations. This study shows that extrinsic feedback from developing retinal neurons is important for the temporal expression of intrinsic fate determinants but not for the timing of birth dates. We found no changes in cell cycle exit timing but did find a significant delay in the expression of genes driving the generation only of later- but not earlier-born cells, suggesting that the robustness of this process depends on continuous feedback from earlier-formed cell types. Thus, extrinsic cues selectively influence cell fate determinant progression, which may explain the function of the retinal histogenic order observed. J. Comp. Neurol. 524:2553-2566, 2016. © 2016 Wiley Periodicals, Inc. PMID:26850379

  11. Induced Pluripotent Stem Cells and Outer Retinal Disease

    PubMed Central

    Yang, Jin; Cai, Bingcui; Glencer, Patrick; Li, Zhiqing; Zhang, Xiaomin; Li, Xiaorong

    2016-01-01

    The retina, which is composed of multiple layers of differing cell types, has been considered the first choice for gene therapy, disease modeling, and stem cell-derived retinal cell transplant therapy. Because of its special characteristics, the retina, located in the posterior part of the eye, can be well observed directly after gene therapy or transplantation. The blood-retinal barrier is part of a specialized ocular microenvironment that is immune privileged. This protects transplanted cells and tissue. Having two eyes makes perfect natural control possible after a single eye receives gene or stem cell therapy. For this reason, research about exploring retinal diseases' underlying molecular mechanisms and potential therapeutic approach using stem cell technique has been developing rapidly. This review is to present an up-to-date summary of the iPSC's sources, variations, differentiation methods, and the wide-ranging application of iPSCs-RPCS or iPSCs-RPE on retinal disease modeling, diagnostics, and therapeutics. PMID:26880948

  12. Transcriptional regulation of PRPF31 gene expression by MSR1 repeat elements causes incomplete penetrance in retinitis pigmentosa

    PubMed Central

    Rose, Anna M.; Shah, Amna Z.; Venturini, Giulia; Krishna, Abhay; Chakravarti, Aravinda; Rivolta, Carlo; Bhattacharya, Shomi S.

    2016-01-01

    PRPF31-associated retinitis pigmentosa presents a fascinating enigma: some mutation carriers are blind, while others are asymptomatic. We identify the major molecular cause of this incomplete penetrance through three cardinal features: (1) there is population variation in the number (3 or 4) of a minisatellite repeat element (MSR1) adjacent to the PRPF31 core promoter; (2) in vitro, 3-copies of the MSR1 element can repress gene transcription by 50 to 115-fold; (3) the higher-expressing 4-copy allele is not observed among symptomatic PRPF31 mutation carriers and correlates with the rate of asymptomatic carriers in different populations. Thus, a linked transcriptional modifier decreases PRPF31 gene expression that leads to haploinsufficiency. This result, taken with other identified risk alleles, allows precise genetic counseling for the first time. We also demonstrate that across the human genome, the presence of MSR1 repeats in the promoters or first introns of genes is associated with greater population variability in gene expression indicating that copy number variation of MSR1s is a generic controller of gene expression and promises to provide new insights into our understanding of gene expression regulation. PMID:26781568

  13. Transcriptional regulation of PRPF31 gene expression by MSR1 repeat elements causes incomplete penetrance in retinitis pigmentosa.

    PubMed

    Rose, Anna M; Shah, Amna Z; Venturini, Giulia; Krishna, Abhay; Chakravarti, Aravinda; Rivolta, Carlo; Bhattacharya, Shomi S

    2016-01-01

    PRPF31-associated retinitis pigmentosa presents a fascinating enigma: some mutation carriers are blind, while others are asymptomatic. We identify the major molecular cause of this incomplete penetrance through three cardinal features: (1) there is population variation in the number (3 or 4) of a minisatellite repeat element (MSR1) adjacent to the PRPF31 core promoter; (2) in vitro, 3-copies of the MSR1 element can repress gene transcription by 50 to 115-fold; (3) the higher-expressing 4-copy allele is not observed among symptomatic PRPF31 mutation carriers and correlates with the rate of asymptomatic carriers in different populations. Thus, a linked transcriptional modifier decreases PRPF31 gene expression that leads to haploinsufficiency. This result, taken with other identified risk alleles, allows precise genetic counseling for the first time. We also demonstrate that across the human genome, the presence of MSR1 repeats in the promoters or first introns of genes is associated with greater population variability in gene expression indicating that copy number variation of MSR1s is a generic controller of gene expression and promises to provide new insights into our understanding of gene expression regulation. PMID:26781568

  14. Viral Vectors for Gene Therapy: Current State and Clinical Perspectives.

    PubMed

    Lukashev, A N; Zamyatnin, A A

    2016-07-01

    Gene therapy is the straightforward approach for the application of recent advances in molecular biology into clinical practice. One of the major obstacles in the development of gene therapy is the delivery of the effector to and into the target cell. Unfortunately, most methods commonly used in laboratory practice are poorly suited for clinical use. Viral vectors are one of the most promising methods for gene therapy delivery. Millions of years of evolution of viruses have resulted in the development of various molecular mechanisms for entry into cells, long-term survival within cells, and activation, inhibition, or modification of the host defense mechanisms at all levels. The relatively simple organization of viruses, small genome size, and evolutionary plasticity allow modifying them to create effective instruments for gene therapy approaches. This review summarizes the latest trends in the development of gene therapy, in particular, various aspects and prospects of the development of clinical products based on viral delivery systems. PMID:27449616

  15. A snapshot of gene therapy in Latin America.

    PubMed

    Linden, Rafael; Matte, Ursula

    2014-03-01

    Gene therapy attempts the insertion and expression of exogenous genetic material in cells for therapeutic purposes. Conceived in the 1960s, gene therapy reached its first clinical trial at the end of the 1980s and by December 2013 around 600 genuine open clinical trials of gene therapy were registered at NIH Clinical Trials Database. Here, we summarize the current efforts towards the development of gene therapy in Latin America. Our survey shows that the number of scientists involved in the development of gene therapy and DNA vaccines in Latin America is still very low. Higher levels of investment in this technology are necessary to boost the advancement of innovation and intellectual property in this field in a way that would ease both the social and financial burden of various medical conditions in Latin America. PMID:24764763

  16. A snapshot of gene therapy in Latin America

    PubMed Central

    Linden, Rafael; Matte, Ursula

    2014-01-01

    Gene therapy attempts the insertion and expression of exogenous genetic material in cells for therapeutic purposes. Conceived in the 1960s, gene therapy reached its first clinical trial at the end of the 1980s and by December 2013 around 600 genuine open clinical trials of gene therapy were registered at NIH Clinical Trials Database. Here, we summarize the current efforts towards the development of gene therapy in Latin America. Our survey shows that the number of scientists involved in the development of gene therapy and DNA vaccines in Latin America is still very low. Higher levels of investment in this technology are necessary to boost the advancement of innovation and intellectual property in this field in a way that would ease both the social and financial burden of various medical conditions in Latin America. PMID:24764763

  17. Advances in Gene Therapy for Diseases of the Eye

    PubMed Central

    Petit, Lolita; Khanna, Hemant; Punzo, Claudio

    2016-01-01

    Over the last few years, huge progress has been made with regard to the understanding of molecular mechanisms underlying the pathogenesis of neurodegenerative diseases of the eye. Such knowledge has led to the development of gene therapy approaches to treat these devastating disorders. Challenges regarding the efficacy and efficiency of therapeutic gene delivery have driven the development of novel therapeutic approaches, which continue to evolve the field of ocular gene therapy. In this review article, we will discuss the evolution of preclinical and clinical strategies that have improved gene therapy in the eye, showing that treatment of vision loss has a bright future. PMID:27178388

  18. Advances in Gene Therapy for Diseases of the Eye.

    PubMed

    Petit, Lolita; Khanna, Hemant; Punzo, Claudio

    2016-08-01

    Over the last few years, huge progress has been made with regard to the understanding of molecular mechanisms underlying the pathogenesis of neurodegenerative diseases of the eye. Such knowledge has led to the development of gene therapy approaches to treat these devastating disorders. Challenges regarding the efficacy and efficiency of therapeutic gene delivery have driven the development of novel therapeutic approaches, which continue to evolve the field of ocular gene therapy. In this review article, we will discuss the evolution of preclinical and clinical strategies that have improved gene therapy in the eye, showing that treatment of vision loss has a bright future. PMID:27178388

  19. Clock genes, melanopsins, melatonin, and dopamine key enzymes and their modulation by light and glutamate in chicken embryonic retinal cells.

    PubMed

    Lima, Leonardo Henrique Ribeiro Graciani de; Santos, Kátia Pereira dos; Lauro Castrucci, Ana Maria de

    2011-03-01

    The avian circadian system is composed of the retina, the mammalian homolog region of the suprachiasmatic nucleus (SNC), and the pineal gland. The retina, itself, displays many rhythmic physiological events, such as movements of photoreceptor cells, opsin expression, retinal reisomerization, and melatonin and dopamine production and secretion. Altogether, these rhythmic events are coordinated to predict environmental changes in light conditions during the day, optimizing retina function. The authors investigated the expression pattern of the melanopsin genes Opn4x and Opn4m, the clock genes Clock and Per2, and the genes for the key enzymes N-Acetyltransferase and Tyrosine Hidroxylase in chicken embryo dispersed retinal cells. Primary cultures of chicken retina from 8-day-old embryos were kept in constant dark (DD), in 12-h light/12-h dark (12L:12D), in 12L:12D followed by DD, or in DD in the absence or presence of 100 µM glutamate for 12 h. Total RNA was extracted throughout a 24-h span, every 3 h starting at zeitgeber time 0 (ZT0) of the 6th day, and submitted to reverse transcriptase-polymerase chain reaction (RT-PCR) followed by quantitative PCR (qPCR) for mRNA quantification. The data showed no rhythmic pattern of transcription for any gene in cells kept in DD. However under a light-dark cycle, Clock, Per2, Opn4m, N-Acetyltransferase, and Tyrosine Hydroxylase exhibited rhythmic patterns of transcription. In DD, 100 µM glutamate was able to induce rhythmic expression of Clock, strongly inhibited the expression of Tyrosine Hydroxylase, and, only at some ZTs, of Opn4x and Opn4m. The neurotransmitter had no effect on Per2 and N-Acetyltransferase transcription. The authors confirmed the expression of the protein OPN4x by immunocytochemistry. These results suggest that chicken embryonic retinal cells contain a functional circadian clock, whose synchronization requires light-dark cycle or glutamate stimuli. PMID:21231870

  20. Glucocorticoids induce transactivation of tight junction genes occludin and claudin-5 in retinal endothelial cells via a novel cis-element.

    PubMed

    Felinski, Edward A; Cox, Amy E; Phillips, Brett E; Antonetti, David A

    2008-06-01

    Tight junctions between vascular endothelial cells help to create the blood-brain and blood-retinal barriers. Breakdown of the retinal tight junction complex is problematic in several disease states including diabetic retinopathy. Glucocorticoids can restore and/or preserve the endothelial barrier to paracellular permeability, although the mechanism remains unclear. We show that glucocorticoid treatment of primary retinal endothelial cells increases content of the tight junction proteins occludin and claudin-5, co-incident with an increase in barrier properties of endothelial monolayers. The glucocorticoid receptor antagonist RU486 reverses both the glucocorticoid-stimulated increase in occludin content and the increase in barrier properties. Transcriptional activity from the human occludin and claudin-5 promoters increases in retinal endothelial cells upon glucocorticoid treatment, and is dependent on the glucocorticoid receptor (GR) as demonstrated by siRNA. Deletion analysis of the occludin promoter reveals a 205bp sequence responsible for the glucocorticoid response. However, this region does not possess a canonical glucocorticoid response element and does not bind to the GR in a chromatin immunoprecipitation (ChIP) assay. Mutational analysis of this region revealed a novel 40bp occludin enhancer element (OEE), containing two highly conserved regions of 10 and 13 base pairs, that is both necessary and sufficient for glucocorticoid-induced gene expression in retinal endothelial cells. These data suggest a novel mechanism for glucocorticoid induction of vascular endothelial barrier properties through increased occludin and claudin-5 gene expression. PMID:18501346

  1. The role of pharmacogenetics and advances in gene therapy in the treatment of diabetic retinopathy.

    PubMed

    Agarwal, Aniruddha; Ingham, Sally A; Harkins, Keegan A; Do, Diana V; Nguyen, Quan Dong

    2016-02-01

    Diabetic retinopathy (DR) and its complications such as diabetic macular edema continue to remain a major cause for legal blindness in the developed world. While the introduction of anti-tVEGF agents has significantly improved visual outcomes of patients with DR, unpredictable response, largely due to genetic polymorphisms, appears to be a challenge with this therapy. With advances in identification of various genetic biomarkers, novel therapeutic strategies consisting of gene transfer are being developed and tested for patients with DR. Application of pharmacogenetic principles appears to be a promising futuristic strategy to attenuate diabetes-mediated retinal vasculopathy. In this comprehensive review, data from recent studies in the field of pharmacogenomics for the treatment of DR have been provided. PMID:26807609

  2. [Familial forms of central nervous system cavernomas: from recognition to gene therapy].

    PubMed

    Labauge, P

    2007-06-01

    Ten percent of all cavernomas are familial forms. 300 independent families have been identified in France since 1995. Clinical manifestations are more frequent in familial (50%) than in sporadic forms (5%). The symptoms are the same in both forms: epilepsy, hemorrhages, neurological focal deficits and headache, but hemorrhages are more frequent and the age of revelation is younger, before 30 years. It is also frequent to observe extraneural location, cutaneous and retinal. On MRI, four types of lesional aspects were described and lesions are multiple in all cases with numerous "de novo" cavernomas. The prognostic does not depend on the number of lesions, but on their topography, especially in the brain stem. Familial forms may be considered not only as a neurological but as a systemic disease for which global management with a genetic counseling should be considered. Gene therapy is not today available, but perhaps in the future. PMID:17498752

  3. Identification of a Novel Gene on 10q22.1 Causing Autosomal Dominant Retinitis Pigmentosa (adRP)

    PubMed Central

    Sullivan, Lori S.; Bowne, Sara J.; Koboldt, Daniel C.; Blanton, Susan H.; Wheaton, Dianna K.; Avery, Cheryl E.; Cadena, Elizabeth D.; Koenekoop, Robert K.; Fulton, Robert S.; Wilson, Richard K.; Weinstock, George M.; Lewis, Richard A.; Birch, David G.

    2016-01-01

    Whole-genome linkage mapping identified a region on chromosome 10q21.3–q22.1 with a maximum LOD score of 3.0 at 0 % recombination in a six-generation family with autosomal dominant retinitis pigmentosa (adRP). All known adRP genes and X-linked RP genes were excluded in the family by a combination of methods. Whole-exome next-generation sequencing revealed a missense mutation in hexokinase 1, HK1 c.2539G > A, p.Glu847Lys, tracking with disease in all affected family members. One severely-affected male is homozygous for this region by linkage analysis and has two copies of the mutation. No other potential mutations were detected in the linkage region nor were any candidates identified elsewhere in the genome. Subsequent testing detected the same mutation in four additional, unrelated adRP families, for a total of five mutations in 404 probands tested (1.2 %). Of the five families, three are from the Acadian population in Louisiana, one is French Canadian and one is Sicilian. Haplotype analysis of the affected chromosome in each family and the homozygous individual revealed a rare, shared haplotype of 450 kb, suggesting an ancient founder mutation. HK1 is a widely-expressed gene, with multiple, abundant retinal transcripts, coding for hexokinase 1. Hexokinase catalyzes phosphorylation of glucose to glusose-6-phospate, the first step in glycolysis. The Glu847Lys mutation is in a highly-conserved site, outside of the active site or known functional sites. PMID:26427411

  4. Identification of a Novel Gene on 10q22.1 Causing Autosomal Dominant Retinitis Pigmentosa (adRP).

    PubMed

    Daiger, Stephen P; Sullivan, Lori S; Bowne, Sara J; Koboldt, Daniel C; Blanton, Susan H; Wheaton, Dianna K; Avery, Cheryl E; Cadena, Elizabeth D; Koenekoop, Robert K; Fulton, Robert S; Wilson, Richard K; Weinstock, George M; Lewis, Richard A; Birch, David G

    2016-01-01

    Whole-genome linkage mapping identified a region on chromosome 10q21.3-q22.1 with a maximum LOD score of 3.0 at 0 % recombination in a six-generation family with autosomal dominant retinitis pigmentosa (adRP). All known adRP genes and X-linked RP genes were excluded in the family by a combination of methods. Whole-exome next-generation sequencing revealed a missense mutation in hexokinase 1, HK1 c.2539G > A, p.Glu847Lys, tracking with disease in all affected family members. One severely-affected male is homozygous for this region by linkage analysis and has two copies of the mutation. No other potential mutations were detected in the linkage region nor were any candidates identified elsewhere in the genome. Subsequent testing detected the same mutation in four additional, unrelated adRP families, for a total of five mutations in 404 probands tested (1.2 %). Of the five families, three are from the Acadian population in Louisiana, one is French Canadian and one is Sicilian. Haplotype analysis of the affected chromosome in each family and the homozygous individual revealed a rare, shared haplotype of 450 kb, suggesting an ancient founder mutation. HK1 is a widely-expressed gene, with multiple, abundant retinal transcripts, coding for hexokinase 1. Hexokinase catalyzes phosphorylation of glucose to glusose-6-phospate, the first step in glycolysis. The Glu847Lys mutation is in a highly-conserved site, outside of the active site or known functional sites. PMID:26427411

  5. Nanocarriers of nanotechnology in retinal diseases.

    PubMed

    Al-Halafi, Ali M

    2014-10-01

    We are approaching a new era of retinal pharmacotherapy where new drugs are rapidly being worked out for the treatment of posterior-segment disease. Recent development in ocular drug delivery systems research has provided new insights into drug development, and the use of nanoparticles for drug delivery is thus a promising excellent approach for advanced therapy of ocular diseases. The primary goal is to develop a variety of drug delivery systems to complement and further enhance the efficacy of the available new medications. The ideal sustained release technology will provide a high level of safety with continuous release over an extended period of time while maintaining almost total drug bioactivity. The use of nanocarriers, such as cyclodextrin nanoparticle suspension, liposomes, nanospheres and, nanoemulsions for gene therapy of retinal diseases has been highlighted in this review. PMID:25473348

  6. 75 FR 65640 - Cellular, Tissue and Gene Therapies Advisory Committee; Notice of Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-26

    ... HUMAN SERVICES Food and Drug Administration Cellular, Tissue and Gene Therapies Advisory Committee... and Gene Therapies Advisory Committee. General Function of the Committee: To provide advice and... Tumor Vaccines and Biotechnology Branch, Office of Cellular, Tissue and Gene Therapies, Center...

  7. Retroviral Integrations in Gene Therapy Trials

    PubMed Central

    Biasco, Luca; Baricordi, Cristina; Aiuti, Alessandro

    2012-01-01

    γ-Retroviral and lentiviral vectors allow the permanent integration of a therapeutic transgene in target cells and have provided in the last decade a delivery platform for several successful gene therapy (GT) clinical approaches. However, the occurrence of adverse events due to insertional mutagenesis in GT treated patients poses a strong challenge to the scientific community to identify the mechanisms at the basis of vector-driven genotoxicity. Along the last decade, the study of retroviral integration sites became a fundamental tool to monitor vector–host interaction in patients overtime. This review is aimed at critically revising the data derived from insertional profiling, with a particular focus on the evidences collected from GT clinical trials. We discuss the controversies and open issues associated to the interpretation of integration site analysis during patient's follow up, with an update on the latest results derived from the use of high-throughput technologies. Finally, we provide a perspective on the future technical development and on the application of these studies to address broader biological questions, from basic virology to human hematopoiesis. PMID:22252453

  8. Duchenne muscular dystrophy gene therapy in the canine model.

    PubMed

    Duan, Dongsheng

    2015-03-01

    Duchenne muscular dystrophy (DMD) is an X-linked lethal muscle disease caused by dystrophin deficiency. Gene therapy has significantly improved the outcome of dystrophin-deficient mice. Yet, clinical translation has not resulted in the expected benefits in human patients. This translational gap is largely because of the insufficient modeling of DMD in mice. Specifically, mice lacking dystrophin show minimum dystrophic symptoms, and they do not respond to the gene therapy vector in the same way as human patients do. Further, the size of a mouse is hundredfolds smaller than a boy, making it impossible to scale-up gene therapy in a mouse model. None of these limitations exist in the canine DMD (cDMD) model. For this reason, cDMD dogs have been considered a highly valuable platform to test experimental DMD gene therapy. Over the last three decades, a variety of gene therapy approaches have been evaluated in cDMD dogs using a number of nonviral and viral vectors. These studies have provided critical insight for the development of an effective gene therapy protocol in human patients. This review discusses the history, current status, and future directions of the DMD gene therapy in the canine model. PMID:25710459

  9. Duchenne Muscular Dystrophy Gene Therapy in the Canine Model

    PubMed Central

    2015-01-01

    Abstract Duchenne muscular dystrophy (DMD) is an X-linked lethal muscle disease caused by dystrophin deficiency. Gene therapy has significantly improved the outcome of dystrophin-deficient mice. Yet, clinical translation has not resulted in the expected benefits in human patients. This translational gap is largely because of the insufficient modeling of DMD in mice. Specifically, mice lacking dystrophin show minimum dystrophic symptoms, and they do not respond to the gene therapy vector in the same way as human patients do. Further, the size of a mouse is hundredfolds smaller than a boy, making it impossible to scale-up gene therapy in a mouse model. None of these limitations exist in the canine DMD (cDMD) model. For this reason, cDMD dogs have been considered a highly valuable platform to test experimental DMD gene therapy. Over the last three decades, a variety of gene therapy approaches have been evaluated in cDMD dogs using a number of nonviral and viral vectors. These studies have provided critical insight for the development of an effective gene therapy protocol in human patients. This review discusses the history, current status, and future directions of the DMD gene therapy in the canine model. PMID:25710459

  10. Characterization of Three-Dimensional Retinal Tissue Derived from Human Embryonic Stem Cells in Adherent Monolayer Cultures.

    PubMed

    Singh, Ratnesh K; Mallela, Ramya K; Cornuet, Pamela K; Reifler, Aaron N; Chervenak, Andrew P; West, Michael D; Wong, Kwoon Y; Nasonkin, Igor O

    2015-12-01

    Stem cell-based therapy of retinal degenerative conditions is a promising modality to treat blindness, but requires new strategies to improve the number of functionally integrating cells. Grafting semidifferentiated retinal tissue rather than progenitors allows preservation of tissue structure and connectivity in retinal grafts, mandatory for vision restoration. Using human embryonic stem cells (hESCs), we derived retinal tissue growing in adherent conditions consisting of conjoined neural retina and retinal pigment epithelial (RPE) cells and evaluated cell fate determination and maturation in this tissue. We found that deriving such tissue in adherent conditions robustly induces all eye field genes (RX, PAX6, LHX2, SIX3, SIX6) and produces four layers of pure populations of retinal cells: RPE (expressing NHERF1, EZRIN, RPE65, DCT, TYR, TYRP, MITF, PMEL), early photoreceptors (PRs) (coexpressing CRX and RCVRN), inner nuclear layer neurons (expressing CALB2), and retinal ganglion cells [RGCs, expressing BRN3B and Neurofilament (NF) 200]. Furthermore, we found that retinal progenitors divide at the apical side of the hESC-derived retinal tissue (next to the RPE layer) and then migrate toward the basal side, similar to that found during embryonic retinogenesis. We detected synaptogenesis in hESC-derived retinal tissue, and found neurons containing many synaptophysin-positive boutons within the RGC and PR layers. We also observed long NF200-positive axons projected by RGCs toward the apical side. Whole-cell recordings demonstrated that putative amacrine and/or ganglion cells exhibited electrophysiological responses reminiscent of those in normal retinal neurons. These responses included voltage-gated Na(+) and K(+) currents, depolarization-induced spiking, and responses to neurotransmitter receptor agonists. Differentiation in adherent conditions allows generation of long and flexible pieces of 3D retinal tissue suitable for isolating transplantable slices of tissue

  11. Gene Therapy, Early Promises, Subsequent Problems, and Recent Breakthroughs

    PubMed Central

    Razi Soofiyani, Saeideh; Baradaran, Behzad; Lotfipour, Farzaneh; Kazemi, Tohid; Mohammadnejad, Leila

    2013-01-01

    Gene therapy is one of the most attractive fields in medicine. The concept of gene delivery to tissues for clinical applications has been discussed around half a century, but scientist’s ability to manipulate genetic material via recombinant DNA technology made this purpose to reality. Various approaches, such as viral and non-viral vectors and physical methods, have been developed to make gene delivery safer and more efficient. While gene therapy initially conceived as a way to treat life-threatening disorders (inborn errors, cancers) refractory to conventional treatment, to date gene therapy is considered for many non–life-threatening conditions including those adversely influence on a patient’s quality of life. Gene therapy has made significant progress, including tangible success, although much slower than was initially predicted. Although, gene therapies still at a fairly primitive stage, it is firmly science based. There is justifiable hope that with enhanced pathobiological understanding and biotechnological improvements, gene therapy will be a standard part of clinical practice within 20 years. PMID:24312844

  12. Advancements in gene transfer-based therapy for hemophilia A

    PubMed Central

    Doering, Christopher B; Spencer, H Trent

    2010-01-01

    Gene therapy has promised clinical benefit to those suffering with hemophilia A, but this benefit has not yet been realized. However, during the past two decades, basic and applied gene therapy research has progressed and the goal of gene therapy for hemophilia A is once again in our sights. The hemophilia A patient population suffers from a disease that requires invasive, lifelong management, is exorbitantly expensive to treat, has geographically limited treatment access and can become untreatable due to immune reactions to the treatment product. Subsequent to the cloning of the factor VIII gene and cDNA in the early 1980s, academic and commercial research laboratories began to pursue gene transfer-based therapies to supplement or supplant the available protein replacement therapy. However, to date, clinical trials for gene therapy of hemophilia A have been unsuccessful. Three trials have been conducted with each having tested a different gene-transfer strategy and each demonstrating that there is a considerable barrier to achieving sustained expression of therapeutic amounts of factor VIII. Recent progress has been made in gene-transfer technology and, relevant to hemophilia A, towards increasing the biosynthetic efficiency of factor VIII. These advances are now being combined to develop novel strategies to treat and possibly cure hemophilia A. PMID:20577574

  13. Genetic and phenotypic variations of inherited retinal diseases in dogs: the power of within- and across-breed studies

    PubMed Central

    Acland, Gregory M.

    2014-01-01

    Considerable clinical and molecular variations have been known in retinal blinding diseases in man and also in dogs. Different forms of retinal diseases occur in specific breed(s) caused by mutations segregating within each isolated breeding population. While molecular studies to find genes and mutations underlying retinal diseases in dogs have benefited largely from the phenotypic and genetic uniformity within a breed, within- and across-breed variations have often played a key role in elucidating the molecular basis. The increasing knowledge of phenotypic, allelic, and genetic heterogeneities in canine retinal degeneration has shown that the overall picture is rather more complicated than initially thought. Over the past 20 years, various approaches have been developed and tested to search for genes and mutations underlying genetic traits in dogs, depending on the availability of genetic tools and sample resources. Candidate gene, linkage analysis, and genome-wide association studies have so far identified 24 mutations in 18 genes underlying retinal diseases in at least 58 dog breeds. Many of these genes have been associated with retinal diseases in humans, thus providing opportunities to study the role in pathogenesis and in normal vision. Application in therapeutic interventions such as gene therapy has proven successful initially in a naturally occurring dog model followed by trials in human patients. Other genes whose human homologs have not been associated with retinal diseases are potential candidates to explain equivalent human diseases and contribute to the understanding of their function in vision. PMID:22065099

  14. Whole Exome Sequencing Reveals Mutations in Known Retinal Disease Genes in 33 out of 68 Israeli Families with Inherited Retinopathies

    PubMed Central

    Beryozkin, Avigail; Shevah, Elia; Kimchi, Adva; Mizrahi-Meissonnier, Liliana; Khateb, Samer; Ratnapriya, Rinki; Lazar, Csilla H.; Blumenfeld, Anat; Ben-Yosef, Tamar; Hemo, Yitzhak; Pe’er, Jacob; Averbuch, Eduard; Sagi, Michal; Boleda, Alexis; Gieser, Linn; Zlotogorski, Abraham; Falik-Zaccai, Tzipora; Alimi-Kasem, Ola; Jacobson, Samuel G.; Chowers, Itay; Swaroop, Anand; Banin, Eyal; Sharon, Dror

    2015-01-01

    Whole exome sequencing (WES) is a powerful technique for identifying sequence changes in the human genome. The goal of this study was to delineate the genetic defects in patients with inherited retinal diseases (IRDs) using WES. WES was performed on 90 patient DNA samples from 68 families and 226 known genes for IRDs were analyzed. Sanger sequencing was used to validate potential pathogenic variants that were also subjected to segregation analysis in families. Thirty-three causative mutations (19 novel and 14 known) in 25 genes were identified in 33 of the 68 families. The vast majority of mutations (30 out of 33) have not been reported in the Israeli and the Palestinian populations. Nine out of the 33 mutations were detected in additional families from the same ethnic population, suggesting a founder effect. In two families, identified phenotypes were different from the previously reported clinical findings associated with the causative gene. This is the largest genetic analysis of IRDs in the Israeli and Palestinian populations to date. We also demonstrate that WES is a powerful tool for rapid analysis of known disease genes in large patient cohorts. PMID:26306921

  15. Germ-line gene therapy and the medical imperative.

    PubMed

    Munson, Ronald; Davis, Lawrence H

    1992-06-01

    Somatic cell gene therapy has yielded promising results. If germ cell gene therapy can be developed, the promise is even greater: hundreds of genetic diseases might be virtually eliminated. But some claim the procedure is morally unacceptable. We thoroughly and sympathetically examine several possible reasons for this claim but find them inadequate. There is no moral reason, then, not to develop and employ germ-line gene therapy. Taking the offensive, we argue next that medicine has a prima facie moral obligation to do so. PMID:11645742

  16. Isolated and Syndromic Retinal Dystrophy Caused by Biallelic Mutations in RCBTB1, a Gene Implicated in Ubiquitination.

    PubMed

    Coppieters, Frauke; Ascari, Giulia; Dannhausen, Katharina; Nikopoulos, Konstantinos; Peelman, Frank; Karlstetter, Marcus; Xu, Mingchu; Brachet, Cécile; Meunier, Isabelle; Tsilimbaris, Miltiadis K; Tsika, Chrysanthi; Blazaki, Styliani V; Vergult, Sarah; Farinelli, Pietro; Van Laethem, Thalia; Bauwens, Miriam; De Bruyne, Marieke; Chen, Rui; Langmann, Thomas; Sui, Ruifang; Meire, Françoise; Rivolta, Carlo; Hamel, Christian P; Leroy, Bart P; De Baere, Elfride

    2016-08-01

    Inherited retinal dystrophies (iRDs) are a group of genetically and clinically heterogeneous conditions resulting from mutations in over 250 genes. Here, homozygosity mapping and whole-exome sequencing (WES) in a consanguineous family revealed a homozygous missense mutation, c.973C>T (p.His325Tyr), in RCBTB1. In affected individuals, it was found to segregate with retinitis pigmentosa (RP), goiter, primary ovarian insufficiency, and mild intellectual disability. Subsequent analysis of WES data in different cohorts uncovered four additional homozygous missense mutations in five unrelated families in whom iRD segregates with or without syndromic features. Ocular phenotypes ranged from typical RP starting in the second decade to chorioretinal dystrophy with a later age of onset. The five missense mutations affect highly conserved residues either in the sixth repeat of the RCC1 domain or in the BTB1 domain. A founder haplotype was identified for mutation c.919G>A (p.Val307Met), occurring in two families of Mediterranean origin. We showed ubiquitous mRNA expression of RCBTB1 and demonstrated predominant RCBTB1 localization in human inner retina. RCBTB1 was very recently shown to be involved in ubiquitination, more specifically as a CUL3 substrate adaptor. Therefore, the effect on different components of the CUL3 and NFE2L2 (NRF2) pathway was assessed in affected individuals' lymphocytes, revealing decreased mRNA expression of NFE2L2 and several NFE2L2 target genes. In conclusion, our study puts forward mutations in RCBTB1 as a cause of autosomal-recessive non-syndromic and syndromic iRD. Finally, our data support a role for impaired ubiquitination in the pathogenetic mechanism of RCBTB1 mutations. PMID:27486781

  17. Early changes in gene expression induced by blue light irradiation of A2E-laden retinal pigment epithelial cells

    PubMed Central

    van der Burght, Barbro W.; Hansen, Morten; Olsen, Jørgen; Zhou, Jilin; Wu, Yalin; Nissen, Mogens H.; Sparrow, Janet R.

    2016-01-01

    Purpose Accumulation of bisretinoids as lipofuscin in retinal pigment epithelial (RPE) cells is implicated in the pathogenesis of some blinding diseases including age-related macular degeneration (AMD). To identify genes whose expression may change under conditions of bisretinoid accumulation, we investigated the differential gene expression in RPE cells that had accumulated the lipofuscin fluorophore A2E and were exposed to blue light (430 nm). Methods A2E-laden RPE cells were exposed to blue light (A2E/430 nm) at various time intervals. Cell death was quantified using Dead Red staining, and RNA levels for the entire genome was determined using DNA microarrays (Affymetrix GeneChip Human Genome 2.0 Plus). Array results for selected genes were confirmed by real-time reverse-transcriptase polymerase chain reaction. Results Principal component analysis revealed that the A2E-laden RPE cells irradiated with blue light were clearly distinguishable from the control samples. We found differential regulation of genes belonging to the following functional groups: transcription factors, stress response, apoptosis and immune response. Among the last mentioned were downregulation of four genes that coded for proteins that have an inhibitory effect on the complement cascade: (complement factor H, complement factor H-related 1, complement factor I and vitronectin) and of two belonging to the classical pathway (complement component 1, s subcomponent and complement component 1, r subcomponent). Conclusion This study demonstrates that blue light irradiation of A2E-laden RPE cells can alter the transcription of genes belonging to different functional pathways including stress response, apoptosis and the immune response. We suggest that these molecules may be associated to the pathogenesis of AMD and can potentially serve as future therapeutic targets. PMID:23742627

  18. Current progress in suicide gene therapy for cancer.

    PubMed

    Yazawa, Kazuyuki; Fisher, William E; Brunicardi, F Charles

    2002-07-01

    Standard chemotherapeutic agents and ionizing radiation destroy dividing cells. Because tumor cells divide more rapidly than normal cells, there is a therapeutic index in which damage to the cancer cells is maximized while keeping the toxicity to the normal host cells acceptable. Suicide gene therapy strives to deliver genes to the cancer cells, which convert nontoxic prodrugs into active chemotherapeutic agents. With this strategy, the systemically administered prodrug is converted to the active chemotherapeutic agent only in cancer cells, thereby allowing a maximal therapeutic effect while limiting systemic toxicity. A literature search was conducted using the MEDLINE database from 1990 to 2001 to identify articles related to suicide gene therapy for cancer. A number of suicide gene systems have been identified, including the herpes simplex virus thymidine kinase gene, the cytosine deaminase gene, the varicella-zoster virus thymidine kinase gene, the nitroreductase gene, the Escherichia coli gpt gene, and the E. coli Deo gene. Various vectors, including liposomes, retroviruses, and adenoviruses, have been used to transfer these suicide genes to tumor cells. These strategies have been effective in cell culture experiments, laboratory animals, and some early clinical trials. Advances in tissue- and cell-specific delivery of suicide genes using specific promoters will improve the clinical utility of suicide gene therapy. PMID:11948367

  19. Gene Therapy and Cell-Based Therapies for Therapeutic Angiogenesis in Peripheral Artery Disease

    PubMed Central

    Nakagami, Hironori; Koriyama, Hiroshi; Morishita, Ryuichi

    2013-01-01

    Gene therapy and cell-based therapy have emerged as novel therapies to promote therapeutic angiogenesis in critical limb ischemia (CLI) caused by peripheral artery disease (PAD). Although researchers initially focused on gene therapy using proangiogenic factors, such as vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), and hepatocyte growth factors (HGF), cell therapy using bone marrow mononuclear cells (BMMNCs), mesenchymal stem cells (BMMSCs), G-CSF-mobilized peripheral blood mononuclear cells (M-PBMNCs), and endothelial progenitor cells (EPCs) have also been extensively studied. Based on the elaborate studies and favorable results of basic research, some clinical phase I/II trials have been performed, and the results demonstrate the safety of these approaches and their potential for symptomatic improvement in CLI. However, the phase 3 clinical trials have thus far been limited to gene therapy using the HGF gene. Further studies using well-designed larger placebo-controlled and long-term randomized control trials (RCTs) will clarify the effectiveness of gene therapy and cell-based therapy for the treatment of CLI. Furthermore, the development of efficient gene transfer systems and effective methods for keeping transplanted cells healthy will make these novel therapies more effective and ease the symptoms of CLI. PMID:24294599

  20. The interplay of post-translational modification and gene therapy

    PubMed Central

    Osamor, Victor Chukwudi; Chinedu, Shalom N; Azuh, Dominic E; Iweala, Emeka Joshua; Ogunlana, Olubanke Olujoke

    2016-01-01

    Several proteins interact either to activate or repress the expression of other genes during transcription. Based on the impact of these activities, the proteins can be classified into readers, modifier writers, and modifier erasers depending on whether histone marks are read, added, or removed, respectively, from a specific amino acid. Transcription is controlled by dynamic epigenetic marks with serious health implications in certain complex diseases, whose understanding may be useful in gene therapy. This work highlights traditional and current advances in post-translational modifications with relevance to gene therapy delivery. We report that enhanced understanding of epigenetic machinery provides clues to functional implication of certain genes/gene products and may facilitate transition toward revision of our clinical treatment procedure with effective fortification of gene therapy delivery. PMID:27013864

  1. The interplay of post-translational modification and gene therapy.

    PubMed

    Osamor, Victor Chukwudi; Chinedu, Shalom N; Azuh, Dominic E; Iweala, Emeka Joshua; Ogunlana, Olubanke Olujoke

    2016-01-01

    Several proteins interact either to activate or repress the expression of other genes during transcription. Based on the impact of these activities, the proteins can be classified into readers, modifier writers, and modifier erasers depending on whether histone marks are read, added, or removed, respectively, from a specific amino acid. Transcription is controlled by dynamic epigenetic marks with serious health implications in certain complex diseases, whose understanding may be useful in gene therapy. This work highlights traditional and current advances in post-translational modifications with relevance to gene therapy delivery. We report that enhanced understanding of epigenetic machinery provides clues to functional implication of certain genes/gene products and may facilitate transition toward revision of our clinical treatment procedure with effective fortification of gene therapy delivery. PMID:27013864

  2. Synergistic nanomedicine by combined gene and photothermal therapy.

    PubMed

    Kim, Jinhwan; Kim, Jihoon; Jeong, Cherlhyun; Kim, Won Jong

    2016-03-01

    To date, various nanomaterials with the ability for gene delivery or photothermal effect have been developed in the field of biomedicine. The therapeutic potential of these nanomaterials has raised considerable interests in their use in potential next-generation strategies for effective anticancer therapy. In particular, the advancement of novel nanomedicines utilizing both therapeutic strategies of gene delivery and photothermal effect has generated much optimism regarding the imminent development of effective and successful cancer treatments. In this review, we discuss current research progress with regard to combined gene and photothermal therapy. This review focuses on synergistic therapeutic systems combining gene regulation and photothermal ablation as well as logically designed nano-carriers aimed at enhancing the delivery efficiency of therapeutic genes using the photothermal effect. The examples detailed in this review provide insight to further our understanding of combinatorial gene and photothermal therapy, thus paving the way for the design of promising nanomedicines. PMID:26748259

  3. The use of canine models of inherited retinal degeneration to test novel therapeutic approaches

    PubMed Central

    Beltran, William A.

    2011-01-01

    Inherited retinal degenerations (RDs) are a common cause of blindness in dogs and in humans. Over the past two decades numerous genes causally associated with these diseases have been identified and several canine models have been used to improve our understanding of the molecular mechanisms of RDs, as well as to test the proof of principle and safety of novel therapies. This review briefly summarizes the drug delivery approaches and therapeutic strategies that have been and are currently tested in dogs, with a particular emphasis on corrective gene therapy, and retinal neuroprotection. PMID:19392879

  4. Role of the Retinal Vascular Endothelial Cell in Ocular Disease

    PubMed Central

    Bharadwaj, Arpita S.; Appukuttan, Binoy; Wilmarth, Phillip A.; Pan, Yuzhen; Stempel, Andrew J.; Chipps, Timothy J.; Benedetti, Eric E.; Zamora, David O.; Choi, Dongseok; David, Larry L.; Smith, Justine R.

    2012-01-01

    Retinal endothelial cells line the arborizing microvasculature that supplies and drains the neural retina. The anatomical and physiological characteristics of these endothelial cells are consistent with nutritional requirements and protection of a tissue critical to vision. On the one hand, the endothelium must ensure the supply of oxygen and other nutrients to the metabolically active retina, and allow access to circulating cells that maintain the vasculature or survey the retina for the presence of potential pathogens. On the other hand, the endothelium contributes to the blood-retinal barrier that protects the retina by excluding circulating molecular toxins, microorganisms, and pro-inflammatory leukocytes. Features required to fulfill these functions may also predispose to disease processes, such as retinal vascular leakage and neovascularization, and trafficking of microbes and inflammatory cells. Thus, the retinal endothelial cell is a key participant in retinal ischemic vasculopathies that include diabetic retinopathy and retinopathy of prematurity, and retinal inflammation or infection, as occurs in posterior uveitis. Using gene expression and proteomic profiling, it has been possible to explore the molecular phenotype of the human retinal endothelial cell and contribute to understanding of the pathogenesis of these diseases. In addition to providing support for the involvement of well-characterized endothelial molecules, profiling has the power to identify new players in retinal pathologies. Findings may have implications for the design of new biological therapies. Additional progress in this field is anticipated as other technologies, including epigenetic profiling methods, whole transcriptome shotgun sequencing, and metabolomics, are used to study the human retinal endothelial cell. PMID:22982179

  5. Duchenne muscular dystrophy gene therapy: Lost in translation?

    PubMed Central

    Duan, Dongsheng

    2011-01-01

    A milestone of molecular medicine is the identification of dystrophin gene mutation as the cause of Duchenne muscular dystrophy (DMD). Over the last 2 decades, major advances in dystrophin biology and gene delivery technology have created an opportunity to treat DMD with gene therapy. Remarkable success has been achieved in treating dystrophic mice. Several gene therapy strategies, including plasmid transfer, exon skipping, and adeno-associated virus-mediated microdystrophin therapy, have entered clinical trials. However, therapeutic benefit has not been realized in DMD patients. Bridging the gap between mice and humans is no doubt the most pressing issue facing DMD gene therapy now. In contrast to mice, dystrophin-deficient dogs are genetically and phenotypically similar to human patients. Preliminary gene therapy studies in the canine model may offer critical insights that cannot be obtained from murine studies. It is clear that the canine DMD model may represent an important link between mice and humans. Unfortunately, our current knowledge of dystrophic dogs is limited, and the full picture of disease progression remains to be clearly defined. We also lack rigorous outcome measures (such as in situ force measurement) to monitor therapeutic efficacy in dystrophic dogs. Undoubtedly, maintaining a dystrophic dog colony is technically demanding, and the cost of dog studies cannot be underestimated. A carefully coordinated effort from the entire DMD community is needed to make the best use of the precious dog resource. Successful DMD gene therapy may depend on valid translational studies in dystrophin-deficient dogs. PMID:21691429

  6. Bone Marrow Gene Therapy for HIV/AIDS

    PubMed Central

    Herrera-Carrillo, Elena; Berkhout, Ben

    2015-01-01

    Bone marrow gene therapy remains an attractive option for treating chronic immunological diseases, including acquired immunodeficiency syndrome (AIDS) caused by human immunodeficiency virus (HIV). This technology combines the differentiation and expansion capacity of hematopoietic stem cells (HSCs) with long-term expression of therapeutic transgenes using integrating vectors. In this review we summarize the potential of bone marrow gene therapy for the treatment of HIV/AIDS. A broad range of antiviral strategies are discussed, with a particular focus on RNA-based therapies. The idea is to develop a durable gene therapy that lasts the life span of the infected individual, thus contrasting with daily drug regimens to suppress the virus. Different approaches have been proposed to target either the virus or cellular genes encoding co-factors that support virus replication. Some of these therapies have been tested in clinical trials, providing proof of principle that gene therapy is a safe option for treating HIV/AIDS. In this review several topics are discussed, ranging from the selection of the antiviral molecule and the viral target to the optimal vector system for gene delivery and the setup of appropriate preclinical test systems. The molecular mechanisms used to formulate a cure for HIV infection are described, including the latest antiviral strategies and their therapeutic applications. Finally, a potent combination of anti-HIV genes based on our own research program is described. PMID:26193303

  7. Gene Therapy from the perspective of Systems Biology

    PubMed Central

    Mac Gabhann, Feilim; Annex, Brian H.

    2010-01-01

    Gene therapy research has expanded from its original concept of replacing absent or defective DNA with functional DNA for transcription. Genetic material may be delivered via multiple vectors, including naked plasmid DNA, viruses and even cells with the goal of increasing gene expression; and the targeting of specific tissues or cell types is aimed at decreasing risks of systemic or side effects. As with the development of any drug, there is an amount of empiricism in the choice of gene target, route of administration, dosing and in particular the scaling-up from pre-clinical models to clinical trials. Systems Biology, whose arsenal includes high-throughput experimental and computational studies that account for the complexities of host-disease-therapy interactions, holds significant promise in aiding the development and optimization of gene therapies, including personalized therapies and the identification of biomarkers for success of these strategies. In this review we describe some of the obstacles and successes in gene therapy, using the specific example of growth factor gene delivery to promote angiogenesis and blood vessel remodeling in ischemic diseases; we also make references to anti-angiogenic gene therapy in cancer. The opportunities for Systems Biology and in silico modeling to improve on current outcomes are highlighted. PMID:20886389

  8. Stem Cell Gene Therapy for Fanconi Anemia: Report from the 1st International Fanconi Anemia Gene Therapy Working Group Meeting

    PubMed Central

    Tolar, Jakub; Adair, Jennifer E; Antoniou, Michael; Bartholomae, Cynthia C; Becker, Pamela S; Blazar, Bruce R; Bueren, Juan; Carroll, Thomas; Cavazzana-Calvo, Marina; Clapp, D Wade; Dalgleish, Robert; Galy, Anne; Gaspar, H Bobby; Hanenberg, Helmut; Von Kalle, Christof; Kiem, Hans-Peter; Lindeman, Dirk; Naldini, Luigi; Navarro, Susana; Renella, Raffaele; Rio, Paula; Sevilla, Julián; Schmidt, Manfred; Verhoeyen, Els; Wagner, John E; Williams, David A; Thrasher, Adrian J

    2011-01-01

    Survival rates after allogeneic hematopoietic cell transplantation (HCT) for Fanconi anemia (FA) have increased dramatically since 2000. However, the use of autologous stem cell gene therapy, whereby the patient's own blood stem cells are modified to express the wild-type gene product, could potentially avoid the early and late complications of allogeneic HCT. Over the last decades, gene therapy has experienced a high degree of optimism interrupted by periods of diminished expectation. Optimism stems from recent examples of successful gene correction in several congenital immunodeficiencies, whereas diminished expectations come from the realization that gene therapy will not be free of side effects. The goal of the 1st International Fanconi Anemia Gene Therapy Working Group Meeting was to determine the optimal strategy for moving stem cell gene therapy into clinical trials for individuals with FA. To this end, key investigators examined vector design, transduction method, criteria for large-scale clinical-grade vector manufacture, hematopoietic cell preparation, and eligibility criteria for FA patients most likely to benefit. The report summarizes the roadmap for the development of gene therapy for FA. PMID:21540837

  9. Cystic Fibrosis Gene Therapy in the UK and Elsewhere

    PubMed Central

    Pytel, Kamila M.; Alton, Eric W.F.W.

    2015-01-01

    Abstract The cystic fibrosis transmembrane conductance regulator (CFTR) gene was identified in 1989. This opened the door for the development of cystic fibrosis (CF) gene therapy, which has been actively pursued for the last 20 years. Although 26 clinical trials involving approximately 450 patients have been carried out, the vast majority of these trials were short and included small numbers of patients; they were not designed to assess clinical benefit, but to establish safety and proof-of-concept for gene transfer using molecular end points such as the detection of recombinant mRNA or correction of the ion transport defect. The only currently published trial designed and powered to assess clinical efficacy (defined as improvement in lung function) administered AAV2-CFTR to the lungs of patients with CF. The U.K. Cystic Fibrosis Gene Therapy Consortium completed, in the autumn of 2014, the first nonviral gene therapy trial designed to answer whether repeated nonviral gene transfer (12 doses over 12 months) can lead to clinical benefit. The demonstration that the molecular defect in CFTR can be corrected with small-molecule drugs, and the success of gene therapy in other monogenic diseases, is boosting interest in CF gene therapy. Developments are discussed here. PMID:25838137

  10. Cystic Fibrosis Gene Therapy in the UK and Elsewhere.

    PubMed

    Griesenbach, Uta; Pytel, Kamila M; Alton, Eric W F W

    2015-05-01

    The cystic fibrosis transmembrane conductance regulator (CFTR) gene was identified in 1989. This opened the door for the development of cystic fibrosis (CF) gene therapy, which has been actively pursued for the last 20 years. Although 26 clinical trials involving approximately 450 patients have been carried out, the vast majority of these trials were short and included small numbers of patients; they were not designed to assess clinical benefit, but to establish safety and proof-of-concept for gene transfer using molecular end points such as the detection of recombinant mRNA or correction of the ion transport defect. The only currently published trial designed and powered to assess clinical efficacy (defined as improvement in lung function) administered AAV2-CFTR to the lungs of patients with CF. The U.K. Cystic Fibrosis Gene Therapy Consortium completed, in the autumn of 2014, the first nonviral gene therapy trial designed to answer whether repeated nonviral gene transfer (12 doses over 12 months) can lead to clinical benefit. The demonstration that the molecular defect in CFTR can be corrected with small-molecule drugs, and the success of gene therapy in other monogenic diseases, is boosting interest in CF gene therapy. Developments are discussed here. PMID:25838137

  11. Cardiovascular gene therapy: current status and therapeutic potential

    PubMed Central

    Gaffney, M M; Hynes, S O; Barry, F; O'Brien, T

    2007-01-01

    Gene therapy is emerging as a potential treatment option in patients suffering from a wide spectrum of cardiovascular diseases including coronary artery disease, peripheral vascular disease, vein graft failure and in-stent restenosis. Thus far preclinical studies have shown promise for a wide variety of genes, in particular the delivery of genes encoding growth factors such as vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF) to treat ischaemic vascular disease both peripherally and in coronary artery disease. VEGF as well as other genes such as TIMPs have been used to target the development of neointimal hyperplasia to successfully prevent vein graft failure and in-stent restenosis in animal models. Subsequent phase I trials to examine safety of these therapies have been successful with low levels of serious adverse effects, and albeit in the absence of a placebo group some suggestion of efficacy. Phase 2 studies, which have incorporated a placebo group, have not confirmed this early promise of efficacy. In the next generation of clinical gene therapy trials for cardiovascular disease, many parameters will need to be adjusted in the search for an effective therapy, including the identification of a suitable vector, appropriate gene or genes and an effective vector delivery system for a specific disease target. Here we review the current status of cardiovascular gene therapy and the potential for this approach to become a viable treatment option. PMID:17558439

  12. Gene therapy for CNS diseases – Krabbe disease

    PubMed Central

    Rafi, Mohammad A.

    2016-01-01

    Summary This is a brief report of the 19th Annual Meeting of the American Society of Gene and Cell Therapy that took place from May 4th through May 7th, 2016 in Washington, DC, USA. While the meeting provided many symposiums, lectures, and scientific sessions this report mainly focuses on one of the sessions on the "Gene Therapy for central nervous system (CNS) Diseases" and specifically on the "Gene Therapy for the globoid cell leukodystrophy or Krabbe disease. Two presentations focused on this subject utilizing two animal models of this disease: mice and dog models. Different serotypes of adeno-associate viral vectors (AAV) alone or in combination with bone marrow transplantations were used in these research projects. The Meeting of the ASGCT reflected continuous growth in the fields of gene and cell therapy and brighter forecast for efficient treatment options for variety of human diseases. PMID:27525222

  13. Comparison of Mouse and Human Retinal Pigment Epithelium Gene Expression Profiles: Potential Implications for Age-Related Macular Degeneration

    PubMed Central

    Bennis, Anna; Gorgels, Theo G. M. F.; ten Brink, Jacoline B.; van der Spek, Peter J.; Bossers, Koen; Heine, Vivi M.; Bergen, Arthur A.

    2015-01-01

    Background The human retinal pigment epithelium (RPE) plays an important role in the pathogenesis of age related macular degeneration (AMD). AMD is the leading cause of blindness worldwide. There is currently no effective treatment available. Preclinical studies in AMD mouse models are essential to develop new therapeutics. This requires further in-depth knowledge of the similarities and differences between mouse and human RPE. Methods We performed a microarray study to identify and functionally annotate RPE specific gene expression in mouse and human RPE. We used a meticulous method to determine C57BL/6J mouse RPE signature genes, correcting for possible RNA contamination from its adjacent layers: the choroid and the photoreceptors. We compared the signature genes, gene expression profiles and functional annotations of the mouse and human RPE. Results We defined sets of mouse (64), human (171) and mouse–human interspecies (22) RPE signature genes. Not unexpectedly, our gene expression analysis and comparative functional annotation suggested that, in general, the mouse and human RPE are very similar. For example, we found similarities for general features, like “organ development” and “disorders related to neurological tissue”. However, detailed analysis of the molecular pathways and networks associated with RPE functions, suggested also multiple species-specific differences, some of which may be relevant for the development of AMD. For example, CFHR1, most likely the main complement regulator in AMD pathogenesis was highly expressed in human RPE, but almost absent in mouse RPE. Furthermore, functions assigned to mouse and human RPE expression profiles indicate (patho-) biological differences related to AMD, such as oxidative stress, Bruch’s membrane, immune-regulation and outer blood retina barrier. Conclusion These differences may be important for the development of new therapeutic strategies and translational studies in age-related macular

  14. Inner retinal change in a novel rd1-FTL mouse model of retinal degeneration

    PubMed Central

    Greferath, Ursula; Anderson, Emily E.; Jobling, Andrew I.; Vessey, Kirstan A.; Martinez, Gemma; de Iongh, Robb U.; Kalloniatis, Michael; Fletcher, Erica L.

    2015-01-01

    While photoreceptor loss is the most devastating result of inherited retinal degenerations such as retinitis pigmentosa, inner retinal neurons also undergo significant alteration. Detailing these changes has become important as many vision restorative therapies target the remaining neurons. In this study, the rd1-Fos-Tau-LacZ (rd1-FTL) mouse model was used to explore inner retinal change at a late stage of retinal degeneration, after the loss of photoreceptor nuclei. The rd1-FTL model carries a mutation in the phosphodiesterase gene, Pde6b, and an axonally targeted transgenic beta galactosidase reporter system under the control of the c-fos promoter. Retinae of transgenic rd1-FTL mice and control FTL animals aged 2–12 months were processed for indirect fluorescence immunocytochemistry. At 2 months of age, a time when the majority of photoreceptor nuclei are lost, there was negligible c-fos reporter (FTL) expression, however, from 4 months, reporter expression was observed to increase within subpopulations of amacrine and ganglion cells within the central retina. These areas of inner retinal FTL expression coincided with regions that contained aberrant Müller cells. Specifically, these cells exhibited reduced glutamine synthetase and Kir4.1 immunolabelling, whilst showing evidence of proliferative gliosis (increased cyclinD1 and glial fibrillary acidic protein expression). These changes were limited to distinct regions where cone photoreceptor terminals were absent. Overall, these results highlight that distinct areas of the rd1-FTL central retina undergo significant glial alterations after cone photoreceptor loss. These areas coincide with up-regulation of the c-fos reporter in the inner retina, which may represent a change in neuronal function/plasticity. The rd1-FTL mouse is a useful model system to probe changes that occur in the inner retina at later stages of retinal degeneration. PMID:26283925

  15. Cell and gene therapy in Australia.

    PubMed

    Martiniello-Wilks, R; Rasko, J E J

    2007-01-01

    The expansion of human cells to produce cell therapeutic products for the treatment of disease is, with few exceptions, an experimental therapy. Because cell therapies involve a biological product, often with some genetic or other modification, they require extensive pre-clinical research and development. Cell therapy production processes and premises require licensing by the Therapeutic Goods Administration. In this review, timed to coincide with the international meetings of the ISCT and ISSCR in Australia, we describe some promising cell therapies currently under development. PMID:17464751

  16. Prevailing public perceptions of the ethics of gene therapy.

    PubMed

    Robillard, Julie M; Roskams-Edris, Dylan; Kuzeljevic, Boris; Illes, Judy

    2014-08-01

    Gene therapy research is advancing rapidly, and hopes of treating a large number of brain disorders exist alongside ethical concerns. Most surveys of public attitudes toward these ethical issues are already dated and the content of these surveys has been researcher-driven. To examine current public perceptions, we developed an online instrument that is responsive and relevant to the latest research about ethics, gene therapy, and the brain. The 16-question survey was launched with the platform Amazon Mechanical Turk and was made available to residents of Canada and the United States. The survey was divided into six themes: (1) demographic information, (2) general opinions about gene therapy, (3) medical applications of gene therapy, (4) identity and moral/belief systems, (5) enhancement, and (6) risks. We received and analyzed responses from a total of 467 participants. Our results show that a majority of respondents (>90%) accept gene therapy as a treatment for severe illnesses such as Alzheimer disease, but this receptivity decreases for conditions perceived as less severe such as attention deficit hyperactivity disorder (79%), and for nontherapeutic applications (47%). The greatest area of concern for the application of gene therapy to brain conditions is the fear of not receiving sufficient information before undergoing the treatment. The main ethical concerns with enhancement were the potential for disparities in resource allocation, access to the procedure, and discrimination. When comparing these data with those from the 1990s, our findings suggest that the acceptability of gene therapy is increasing and that this trend is occurring despite lingering concerns over ethical issues. Providing the public and patients with up-to-date information and opportunities to engage in the discourse about areas of research in gene therapy is a priority. PMID:24773182

  17. In Vivo Selection Yields AAV-B1 Capsid for Central Nervous System and Muscle Gene Therapy.

    PubMed

    Choudhury, Sourav R; Fitzpatrick, Zachary; Harris, Anne F; Maitland, Stacy A; Ferreira, Jennifer S; Zhang, Yuanfan; Ma, Shan; Sharma, Rohit B; Gray-Edwards, Heather L; Johnson, Jacob A; Johnson, Aime K; Alonso, Laura C; Punzo, Claudio; Wagner, Kathryn R; Maguire, Casey A; Kotin, Robert M; Martin, Douglas R; Sena-Esteves, Miguel

    2016-08-01

    Adeno-associated viral (AAV) vectors have shown promise as a platform for gene therapy of neurological disorders. Achieving global gene delivery to the central nervous system (CNS) is key for development of effective therapies for many of these diseases. Here we report the isolation of a novel CNS tropic AAV capsid, AAV-B1, after a single round of in vivo selection from an AAV capsid library. Systemic injection of AAV-B1 vector in adult mice and cat resulted in widespread gene transfer throughout the CNS with transduction of multiple neuronal subpopulations. In addition, AAV-B1 transduces muscle, β-cells, pulmonary alveoli, and retinal vasculature at high efficiency. This vector is more efficient than AAV9 for gene delivery to mouse brain, spinal cord, muscle, pancreas, and lung. Together with reduced sensitivity to neutralization by antibodies in pooled human sera, the broad transduction profile of AAV-B1 represents an important improvement over AAV9 for CNS gene therapy. PMID:27117222

  18. Novel approaches and mechanisms in hematopoietic stem cell gene therapy.

    PubMed

    Bigger, Brian W; Wynn, Robert F

    2014-04-01

    Hematopoietic stem cell gene therapy is one of the most exciting clinical tools to emerge from the gene therapy stable. This technology combines the expansion capability of hematopoietic stem cells, capable of replacing the entire blood and immune system of an individual, with the capacity for long-term replacement of one or more gene copies using integrating gene therapy vectors. Hematopoietic stem cell gene therapy benefits significantly from the pre-existing experience of standard blood and marrow transplantation, whilst at the same time having the capacity to deliver a safer and more effective therapy to a wider range of diseases. In this review we summarize the potential of hematopoietic stem cell gene therapy to expand the scope of hematopoietic stem cell transplantation, including the evolution of vector delivery systems and the success and failures of current clinical experience with this treatment. In particular we deal with the incidence of vector mediated transformation in patients and the steps that have been taken to minimize this risk. Finally we discuss the innovations in preclinical development that are likely to drive the future of this field, including the expansion to many more genetic diseases, particularly those affecting the brain. PMID:24759625

  19. Bioethical conflicts of gene therapy: a brief critical review.

    PubMed

    Freire, José Ednésio da Cruz; Medeiros, Suelen Carneiro de; Lopes Neto, Antônio Viana; Monteiro Júnior, José Edvar; Sousa, Antônio Juscelino Sudário; Rocha, Antônio José; Menezes, Léa Maria Bezerra de

    2014-01-01

    Methods and techniques employed in gene therapy are reviewed in parallel with pertinent ethical conflicts. Clinical interventions based on gene therapy techniques preferentially use vectors for the transportation of therapeutic genes, however little is known about the potential risks and damages to the patient. Thus, attending carefully to the clinical complications arising as well as to security is essential. Despite the scientific and technological advances, there are still many uncertainties about the side effects of gene therapy. Moreover, there is a need, above all, to understand the principles of bioethics as both science and ethics, in accordance with its socioecological responsibility, in order to prioritize the health and welfare of man and nature, using properly natural resources and technology. Therefore, it is hard to determine objective results and to which extent the insertion of genes can affect the organism, as well as the ethical implication. PMID:25650850

  20. Extensive intrafamilial and interfamilial phenotypic variation among patients with autosomal dominant retinal dystrophy and mutations in the human RDS/peripherin gene.

    PubMed Central

    Apfelstedt-Sylla, E; Theischen, M; Rüther, K; Wedemann, H; Gal, A; Zrenner, E

    1995-01-01

    Clinical phenotypes of patients with mutations in the human RDS/peripherin gene are described. A 67-year-old woman, who carried a 1 base pair deletion in codon 307, presented with typical late onset autosomal dominant retinitis pigmentosa (RP). In another autosomal dominant pedigree, a nonsense mutation at codon 46 caused 'inverse' retinitis pigmentosa-like fundus changes associated with progressive cone-rod degeneration in a 58-year-old man, whereas his 40-year-old son presented with yellow deposits in the retinal pigment epithelial layer resembling a pattern dystrophy, and with moderately reduced rod and cone function, as determined by two colour dark adapted threshold perimetry and electroretinography. It is suggested that both clinical pictures within this latter family may represent manifestations of fundus flavimaculatus. The clinical data of the three patients provide further evidence for the remarkable variety of disease expression within and between families with mutations in the RDS/peripherin gene. Currently, the most comprehensive statement could be that RDS/peripherin mutations are associated either with typical RP or with various forms of flecked retinal disease. Images PMID:7880786

  1. Molecular analysis and genetic mapping of the rhodopsin gene in families with autosomal dominant retinitis pigmentosa

    SciTech Connect

    Bunge, S.; Wedemann, H.; Samanns, C.; Horn, M.; Schwinger, E.; Gal, A. ); David, D. ); Terwilliger, D.J.; Ott, J. ); Born, L.I. van den )

    1993-07-01

    Eighty-eight patients/families with autosomal dominant retinitis pigmentosa (RP) were screened for rhodopsin mutations. Direct sequencing revealed 13 different mutations in a total of 14 (i.e., 16%) unrelated patients. Five of these mutations (T4K, Q28H, R135G, F220C, and C222R) have not been reported so far. In addition, multipoint linkage analysis was performed on two large families with autosomal dominant RP due to rhodopsin mutations by using five DNA probes from 3q21-q24. No tight linkage was found between the rhodopsin locus (RHO) and D3S47 ([theta][sub max] = 0.08). By six-point analysis, RHO was localized in the region between D3S21 and D3S47, with a maximum lod score of 13.447 directly at D3S20. 13 refs., 1 fig., 2 tabs.

  2. Progresses towards safe and efficient gene therapy vectors

    PubMed Central

    Chira, Sergiu; Jackson, Carlo S.; Oprea, Iulian; Ozturk, Ferhat; Pepper, Michael S.; Diaconu, Iulia; Braicu, Cornelia; Raduly, Lajos-Zsolt; Calin, George A.; Berindan-Neagoe, Ioana

    2015-01-01

    The emergence of genetic engineering at the beginning of the 1970′s opened the era of biomedical technologies, which aims to improve human health using genetic manipulation techniques in a clinical context. Gene therapy represents an innovating and appealing strategy for treatment of human diseases, which utilizes vehicles or vectors for delivering therapeutic genes into the patients' body. However, a few past unsuccessful events that negatively marked the beginning of gene therapy resulted in the need for further studies regarding the design and biology of gene therapy vectors, so that this innovating treatment approach can successfully move from bench to bedside. In this paper, we review the major gene delivery vectors and recent improvements made in their design meant to overcome the issues that commonly arise with the use of gene therapy vectors. At the end of the manuscript, we summarized the main advantages and disadvantages of common gene therapy vectors and we discuss possible future directions for potential therapeutic vectors. PMID:26362400

  3. Development of gene therapy for treatment of age-related macular degeneration.

    PubMed

    Askou, Anne Louise

    2014-07-01

    Intraocular neovascular diseases are the leading cause of blindness in the Western world in individuals over the age of 50. Age-related macular degeneration (AMD) is one of these diseases. Exudative AMD, the late-stage form, is characterized by abnormal neovessel development, sprouting from the choroid into the avascular subretinal space, where it can suddenly cause irreversible damage to the vulnerable photoreceptor (PR) cells essential for our high-resolution, central vision. The molecular basis of AMD is not well understood, but several growth factors have been implicated including vascular endothelial growth factor (VEGF), and the advent of anti-VEGF therapy has markedly changed the outcome of treatment. However, common to all current therapies for exudative AMD are the complications of repeated monthly intravitreal injections, which must be continued throughout one's lifetime to maintain visual benefits. Additionally, some patients do not benefit from established treatments. Strategies providing long-term suppression of inappropriate ocular angiogenesis are therefore needed, and gene therapy offers a potential powerful technique. This study aimed to develop a strategy based on RNA interference (RNAi) for the sustained attenuation of VEGF. We designed a panel of anti-VEGF short hairpin RNAs (shRNA), and based on the most potent shRNAs, microRNA (miRNA)-mimicked hairpins were developed. We demonstrated an additive VEGF silencing effect when we combined the miRNAs in a tricistronic miRNA cluster. To meet the requirements for development of medical treatments for AMD with long-term effects, the shRNA/miRNA is expressed from vectors based on adeno-associated virus (AAV) or lentivirus (LV). Both vector systems have been found superior in terms of transduction efficiency and persistence in gene expression in retinal cells. The capacity of AAV-encoded RNAi effector molecules to silence endogenous VEGF gene expression was evaluated in mouse models, including the model

  4. Complex I Subunit Gene Therapy With NDUFA6 Ameliorates Neurodegeneration in EAE

    PubMed Central

    Talla, Venu; Koilkonda, Rajeshwari; Porciatti, Vittorio; Chiodo, Vince; Boye, Sanford L.; Hauswirth, William W.; Guy, John

    2015-01-01

    Purpose. To address the permanent disability induced by mitochondrial dysfunction in experimental autoimmune encephalomyelitis (EAE). Methods. Mice sensitized for EAE were rescued by intravitreal injection of adeno-associated viral vector serotype 2 with the complex I subunit gene scAAV-NDUFA6Flag. Controls were injected with a mitochondrially targeted red fluorescent protein (scAAV-COX8-cherry). Another group received scAAV-COX8-cherry, but was not sensitized for EAE. Serial pattern electroretinograms (PERGs) and optical coherent tomography (OCT) evaluated visual function and structure of the retina at 1, 3, and 6 months post injection (MPI). Treated mice were killed 6 MPI for histopathology. Immunodetection of cleaved caspase 3 gauged apoptosis. Complex I activity was assessed spectrophotometrically. Expression of NDUFA6Flag in the retina and optic nerve were evaluated between 1 week to 1 month post injection by RT-PCR, immunofluorescence and immunoblotting. Results. Reverse transcription-PCR and immunoblotting confirmed NDUFA6Flag overexpression with immunoprecipitation and blue native PAGE showing integration into murine complex I. Overexpression of NDUFA6Flag in the visual system of EAE mice rescued retinal complex I activity completely, axonal loss by 73%, and retinal ganglion cell (RGC) loss by 88%, RGC apoptosis by 66%, and restored the 33% loss of complex I activity in EAE to normal levels; thereby, preventing loss of vision indicated by the 43% reduction in the PERG amplitudes of EAE mice. Conclusions. NDUFA6 gene therapy provided long-term suppression of neurodegeneration in the EAE animal model suggesting that it may also ameliorate the mitochondrial dysfunction associated with permanent disability in optic neuritis and MS patients. PMID:25613946

  5. Development of Lead Hammerhead Ribozyme Candidates against Human Rod Opsin mRNA for Retinal Degeneration Therapy

    PubMed Central

    Abdelmaksoud, Heba E.; Yau, Edwin H.; Zuker, Michael; Sullivan, Jack M.

    2011-01-01

    To identify lead candidate allele-independent hammerhead ribozymes (hhRz) for the treatment of autosomal dominant mutations in the human rod opsin (RHO) gene, we tested a series of hhRzs for potential to significantly knockdown human RHO gene expression in a human cell expression system. Multiple computational criteria were used to select target mRNA regions likely to be single stranded and accessible to hhRz annealing and cleavage. Target regions are tested for accessibility in a human cell culture expression system where the hhRz RNA and target mRNA and protein are coexpressed. The hhRz RNA is embedded in an adenoviral VAI RNA chimeric RNA of established structure and properties which are critical to the experimental paradigm. The chimeric hhRz-VAI RNA is abundantly transcribed so that the hhRzs are expected to be in great excess over substrate mRNA. HhRz-VAI traffics predominantly to the cytoplasm to colocalize with the RHO mRNA target. Colocalization is essential for second-order annealing reactions. The VAI chimera protects the hhRz RNA from degradation and provides for a long half life. With cell lines chosen for high transfection efficiency and a molar excess of hhRz plasmid over target plasmid, the conditions of this experimental paradigm are specifically designed to evaluate for regions of accessibility of the target mRNA in cellulo. Western analysis was used to measure the impact of hhRz expression on RHO protein expression. Three lead candidate hhRz designs were identified that significantly knockdown target protein expression relative to control (p < 0.05). Successful lead candidates (hhRz CUC↓ 266, hhRz CUC↓ 1411, hhRz AUA↓ 1414) targeted regions of human RHO mRNA that were predicted to be accessible by a bioinformatics approach, whereas regions predicted to be inaccessible supported no knockdown. The maximum opsin protein level knockdown is approximately 30% over a 48 hr paradigm of testing. These results validate a rigorous computational

  6. One-year outcome of bevacizumab therapy for chronic macular edema in central and branch retinal vein occlusions in real-world clinical practice in the UK

    PubMed Central

    Lip, Peck Lin; Malick, Huzaifa; Damer, Kenan; Elsherbiny, Samer; Darrad, Kanupriya M; Mushtaq, Bushra; Mitra, Arijit; Stavrou, Panagiota; Yang, Yit

    2015-01-01

    Background The purpose of this study was to investigate the 12-month outcome of macular edema secondary to both chronic and new central and branch retinal vein occlusions treated with intravitreal bevacizumab in the real-life clinical setting in the UK. Methods Retrospective case notes analysis of consecutive patients with retinal vein occlusions treated with bevacizumab in 2010 to 2012. Outcome measures were visual acuity (measured with Snellen, converted into logMAR [logarithm of the minimum angle of resolution] for statistical calculation) and central retinal thickness at baseline, 4 weeks post-loading phase, and at 1 year. Results There were 56 and 100 patients with central and branch retinal vein occlusions, respectively, of whom 62% had chronic edema and received prior therapies and another 32% required additional laser treatments post-baseline bevacizumab. Baseline median visual acuity was 0.78 (interquartile range [IQR] 0.48–1.22) in the central group and 0.6 (IQR 0.3–0.78) in the branch group. In both groups, visual improvement was statistically significant from baseline compared to post-loading (P<0.001 and P=0.03, respectively), but was not significant by month 12 (P=0.058 and P=0.166, respectively); 30% improved by at least three lines and 44% improved by at least one line by month 12. Baseline median central retinal thickness was 449 μm (IQR 388–553) in the central group and 441 μm (IQR 357–501) in the branch group. However, the mean reduction in thickness was statistically significant at post-loading (P<0.001) and at the 12-month time point (P<0.001) for both groups. The average number of injections in 1 year was 4.2 in the central group and 3.3 in the branch group. Conclusion Our large real-world cohort results indicate that bevacizumab introduced to patients with either new or chronic edema due to retinal vein occlusion can result in resolution of edema and stabilization of vision in the first year. PMID:26445525

  7. Gene therapy for inhereted metabolic disorders in companion animals.

    PubMed

    Koeberl, Dwight D; Pinto, Carlos; Brown, Talmage; Chen, Y T

    2009-01-01

    Scientists first described inborn errors of metabolism, also termed inherited disorders of metabolism, early in the 20th century and since then have determined the biochemical and genetic bases of a great number of these disorders both in humans and in an increasing number of companion animals. The availability of metabolic screening tests has advanced the biochemical and genetic characterization in affected breeds of companion animals of inherited metabolic disorders involving amino acid, carbohydrate, fatty acid, and metal metabolism. Advances in gene therapy have led to the development of new treatments for inherited disorders of metabolism, and animal models have played a critical role in this research. For example, glycogen storage disease type Ia in dogs was highly responsive to adeno-associated viral vectormediated gene therapy, which prolonged survival and for more than a year prevented hypoglycemia during fasting. Gene therapy for other glycogen storage diseases and metabolic disorders will also be feasible. The establishment of a breeding colony and the ability to sustain affected animals are critical steps toward evaluating the safety and efficacy of gene therapy with clinically relevant endpoints. The further development of gene therapy for inherited disorders of metabolism could lead to curative therapy for affected humans and animals alike. PMID:19293457

  8. Therapeutic Prospects of Gene Therapy for Atrial Fibrillation.

    PubMed

    Farraha, Melad; Chong, James J H; Kizana, Eddy

    2016-08-01

    Atrial Fibrillation (AF) is one of the most common types of cardiac arrhythmias experienced in clinical practice, increasing the risk of stroke, dementia, myocardial infarction and death. Currently available options for the treatment of AF use either pharmacological agents or catheter-based ablation therapies to restore sinus rhythm or control the ventricular response rate. These current treatment options are suboptimal at best, motivating research into discovering more effective and innovative ways to treat AF. Gene therapy is being explored for its potential to treat various human conditions including cardiac arrhythmias. Gene transfer vectors with increasing transduction efficiency and biosafety have been developed and trialled for cardiovascular disease treatment. With an improved understanding of the molecular mechanisms of AF, several gene therapy targets have been identified and evaluated in an attempt to rate or rhythm control the heart during AF. This review will discuss the gene therapy vectors in use today and methods for delivery of these vectors to the atrium. Further, it will evaluate several gene therapy strategies and approaches for sinus rhythm restoration and ventricular rate control that have the potential to emerge as a therapy for AF. PMID:27262391

  9. Obstacles and future of gene therapy for hemophilia

    PubMed Central

    Arruda, Valder R; Samelson-Jones, Ben J

    2015-01-01

    Introduction The recent success of early-phase clinical trials for adeno-associated viral (AAV) liver-directed gene therapy for hemophilia B (HB) demonstrates the potential for gene therapy, in the future, to succeed protein-based prophylaxis therapy for HB. Significant obstacles, however, need to be overcome prior to widespread adoption. The largest obstacles include immune responses to the AAV capsid including preexisting neutralizing antibodies (NAbs) and a delayed cellular immune response. Emerging evidence suggests that the latter is vector-dose dependent. Furthermore, the development and eradication of inhibitors remains a significant safety concern. Similarly, biological differences between Factor VIII and Factor IX (FIX) impose challenges to direct adoption of the successes for HB to hemophilia A (HA). Areas covered The advantages and limitations of the current strategies addressing these obstacles for gene therapy for HB and HA are discussed, as well as vector manufacturing issues relevant to widespread adoption. Alternative strategies including both ex-vivo and in-vivo lentiviral-based methods are discussed, though we focus on AAV-based approaches because of their recent clinical success and potential. Expert opinion Our opinion is that these obstacles can be overcome with current approaches, and AAV-based gene therapy for HB will likely translate into future clinical care. Innovative approaches are, however, likely needed to solve the current problems obstructing HA gene therapy. PMID:26900534

  10. Gene Therapy for Alpha-1 Antitrypsin Deficiency Lung Disease.

    PubMed

    Chiuchiolo, Maria J; Crystal, Ronald G

    2016-08-01

    Alpha-1 antitrypsin (AAT) deficiency, characterized by low plasma levels of the serine protease inhibitor AAT, is associated with emphysema secondary to insufficient protection of the lung from neutrophil proteases. Although AAT augmentation therapy with purified AAT protein is efficacious, it requires weekly to monthly intravenous infusion of AAT purified from pooled human plasma, has the risk of viral contamination and allergic reactions, and is costly. As an alternative, gene therapy offers the advantage of single administration, eliminating the burden of protein infusion, and reduced risks and costs. The focus of this review is to describe the various strategies for AAT gene therapy for the pulmonary manifestations of AAT deficiency and the state of the art in bringing AAT gene therapy to the bedside. PMID:27564673

  11. Gene Therapy in Cardiac Surgery: Clinical Trials, Challenges, and Perspectives

    PubMed Central

    Katz, Michael G.; Fargnoli, Anthony S.; Kendle, Andrew P.; Hajjar, Roger J.; Bridges, Charles R.

    2016-01-01

    The concept of gene therapy was introduced in the 1970s after the development of recombinant DNA technology. Despite the initial great expectations, this field experienced early setbacks. Recent years have seen a revival of clinical programs of gene therapy in different fields of medicine. There are many promising targets for genetic therapy as an adjunct to cardiac surgery. The first positive long-term results were published for adenoviral administration of vascular endothelial growth factor with coronary artery bypass grafting. In this review we analyze the past, present, and future of gene therapy in cardiac surgery. The articles discussed were collected through PubMed and from author experience. The clinical trials referenced were found through the Wiley clinical trial database (http://www.wiley.com/legacy/wileychi/genmed/clinical/) as well as the National Institutes of Health clinical trial database (Clinicaltrials.gov). PMID:26801060

  12. Gene Therapy in Cardiac Surgery: Clinical Trials, Challenges, and Perspectives.

    PubMed

    Katz, Michael G; Fargnoli, Anthony S; Kendle, Andrew P; Hajjar, Roger J; Bridges, Charles R

    2016-06-01

    The concept of gene therapy was introduced in the 1970s after the development of recombinant DNA technology. Despite the initial great expectations, this field experienced early setbacks. Recent years have seen a revival of clinical programs of gene therapy in different fields of medicine. There are many promising targets for genetic therapy as an adjunct to cardiac surgery. The first positive long-term results were published for adenoviral administration of vascular endothelial growth factor with coronary artery bypass grafting. In this review we analyze the past, present, and future of gene therapy in cardiac surgery. The articles discussed were collected through PubMed and from author experience. The clinical trials referenced were found through the Wiley clinical trial database (http://www.wiley.com/legacy/wileychi/genmed/clinical/) as well as the National Institutes of Health clinical trial database (Clinicaltrials.gov). PMID:26801060

  13. Evaluation of the effectiveness and safety of glucocorticoids intravitreal implant therapy in macular edema due to retinal vein occlusion

    PubMed Central

    Michalska-Małecka, Katarzyna; Gaborek, Aneta; Nowak, Mariusz; Halat, Tomasz; Pawłowska, Mariola; Śpiewak, Dorota

    2016-01-01

    The purpose of this study was to evaluate the impact of intravitreal dexamethasone implant (Ozurdex) on macular morphology and functions in eyes with macular edema (ME) secondary to retinal vein occlusion. Efficacy outcomes of the treatment were best-corrected visual acuity (BCVA) and central retinal thickness (CRT). Safety outcomes were intraocular pressure and cornea endothelial cell density. The study was conducted by the prospective analysis on 36 patients (17 women and 19 men) aged 28–77 years (the average age was 58±15 years) treated with the injection of dexamethasone implant because of the persistent ME at the Department of Ophthalmology and Ophthalmology Outpatient Clinic of the University Centre of Ophthalmology and Oncology in Katowice. The studied group included 16 patients with central retinal vein occlusion (16 eyes), and 20 patients with branch retinal vein occlusion (20 eyes). We found a significant increase of BCVA after first, second, and third month of treatment. Six months after the treatment, BCVA decreased, although not significantly compared with the value obtained in the third month. Two months after the intravitreal implantation of dexamethasone delivery system, CRT was 338±163 μm and was significantly lower compared with pretreatment value. Between third and sixth month after the treatment, we found insignificant increase of CRT compared with thickness observed in second month. Two months after the treatment, we found an increase in intraocular pressure in 36% of cases and a further decrease during the final visit 6 months after the treatment. During the treatment, there were no significant differences in endothelial cell density in branch retinal vein occlusion and central retinal vein occlusion. We found the intravitreal dexamethasone implant to be safe, well tolerated, and likely to lead to fast morphological and functional improvement of the macula and visual rehabilitation in patients with ME due to retinal vein occlusion. PMID

  14. Novel compound heterozygous mutation in the CNGA1 gene underlie autosomal recessive retinitis pigmentosa in a Chinese family

    PubMed Central

    Jin, Xin; Qu, Ling-Hui; Hou, Bao-Ke; Xu, Hai-Wei; Meng, Xiao-Hong; Pang, Chi-Pui; Yin, Zheng-Qin

    2016-01-01

    Retinitis pigmentosa (RP) describes a group of inherited retinopathies that are characterized by the progressive degeneration of photoreceptor neurons, which causes night blindness, a reduction in the peripheral visual field and decreased visual acuity. More than 50 RP-related genes have been identified. In the present study, we analysed a Chinese family with autosomal recessive RP. We identified a compound heterozygous mutation, c.265delC and c.1537G>A, in CNGA1 using targeted next-generation sequencing (NGS) of RP-causing genes. The mutations were validated in the family members by Sanger sequencing. The mutations co-segregated with the RP phenotype and were absent from ethnically-matched control chromosomes. The mutant (mut) CNGA1 p.(G513R) protein caused by the mis-sense novel mutation c.1537G>A was expressed in vitro. The mut CNGA1 p.(G513R) protein was largely retained inside the cell rather than being targeted to the plasma membrane, suggesting the absence of cGMP-gated cation channels in the plasma membrane would be deleterious to rod photoreceptors, leading lead to RP. PMID:26802146

  15. Development of Viral Vectors for Use in Cardiovascular Gene Therapy

    PubMed Central

    Williams, Paul D.; Ranjzad, Parisa; Kakar, Salik J.; Kingston, Paul A.

    2010-01-01

    Cardiovascular disease represents the most common cause of mortality in the developed world but, despite two decades of promising pre-clinical research and numerous clinical trials, cardiovascular gene transfer has so far failed to demonstrate convincing benefits in the clinical setting. In this review we discuss the various targets which may be suitable for cardiovascular gene therapy and the viral vectors which have to date shown the most potential for clinical use. We conclude with a summary of the current state of clinical cardiovascular gene therapy and the key trials which are ongoing. PMID:21994642

  16. Gene therapy for cancer: regulatory considerations for approval

    PubMed Central

    Husain, S R; Han, J; Au, P; Shannon, K; Puri, R K

    2015-01-01

    The rapidly changing field of gene therapy promises a number of innovative treatments for cancer patients. Advances in genetic modification of cancer and immune cells and the use of oncolytic viruses and bacteria have led to numerous clinical trials for cancer therapy, with several progressing to late-stage product development. At the time of this writing, no gene therapy product has been approved by the United States Food and Drug Administration (FDA). Some of the key scientific and regulatory issues include understanding of gene transfer vector biology, safety of vectors in vitro and in animal models, optimum gene transfer, long-term persistence or integration in the host, shedding of a virus and ability to maintain transgene expression in vivo for a desired period of time. Because of the biological complexity of these products, the FDA encourages a flexible, data-driven approach for preclinical safety testing programs. The clinical trial design should be based on the unique features of gene therapy products, and should ensure the safety of enrolled subjects. This article focuses on regulatory considerations for gene therapy product development and also discusses guidance documents that have been published by the FDA. PMID:26584531

  17. Clinical applications of gene therapy for primary immunodeficiencies.

    PubMed

    Cicalese, Maria Pia; Aiuti, Alessandro

    2015-04-01

    Primary immunodeficiencies (PIDs) have represented a paradigmatic model for successes and pitfalls of hematopoietic stem cells gene therapy. First clinical trials performed with gamma retroviral vectors (γ-RV) for adenosine deaminase severe combined immunodeficiency (ADA-SCID), X-linked SCID (SCID-X1), and Wiskott-Aldrich syndrome (WAS) showed that gene therapy is a valid therapeutic option in patients lacking an HLA-identical donor. No insertional mutagenesis events have been observed in more than 40 ADA-SCID patients treated so far in the context of different clinical trials worldwide, suggesting a favorable risk-benefit ratio for this disease. On the other hand, the occurrence of insertional oncogenesis in SCID-X1, WAS, and chronic granulomatous disease (CGD) RV clinical trials prompted the development of safer vector construct based on self-inactivating (SIN) retroviral or lentiviral vectors (LVs). Here we present the recent results of LV-mediated gene therapy for WAS showing stable multilineage engraftment leading to hematological and immunological improvement, and discuss the differences with respect to the WAS RV trial. We also describe recent clinical results of SCID-X1 gene therapy with SIN γ-RV and the perspectives of targeted genome editing techniques, following early preclinical studies showing promising results in terms of specificity of gene correction. Finally, we provide an overview of the gene therapy approaches for other PIDs and discuss its prospects in relation to the evolving arena of allogeneic transplant. PMID:25860576

  18. Recent advances in gene therapy for lysosomal storage disorders

    PubMed Central

    Rastall, David PW; Amalfitano, Andrea

    2015-01-01

    Lysosomal storage disorders (LSDs) are a group of genetic diseases that result in metabolic derangements of the lysosome. Most LSDs are due to the genetic absence of a single catabolic enzyme, causing accumulation of the enzyme’s substrate within the lysosome. Over time, tissue-specific substrate accumulations result in a spectrum of symptoms and disabilities that vary by LSD. LSDs are promising targets for gene therapy because delivery of a single gene into a small percentage of the appropriate target cells may be sufficient to impact the clinical course of the disease. Recently, there have been several significant advancements in the potential for gene therapy of these disorders, including the first human trials. Future clinical trials will build upon these initial attempts, with an improved understanding of immune system responses to gene therapy, the obstacle that the blood–brain barrier poses for neuropathic LSDs, as well other biological barriers that, when overcome, may facilitate gene therapy for LSDs. In this manuscript, we will highlight the recent innovations in gene therapy for LSDs and discuss the clinical limitations that remain to be overcome, with the goal of fostering an understanding and further development of this important field. PMID:26170711

  19. Gene Therapies for Cancer: Strategies, Challenges and Successes

    PubMed Central

    DAS, SWADESH K.; MENEZES, MITCHELL E.; BHATIA, SHILPA; WANG, XIANG-YANG; EMDAD, LUNI; SARKAR, DEVANAND; FISHER, PAUL B.

    2015-01-01

    Gene therapy, which involves replacement of a defective gene with a functional, healthy copy of that gene, is a potentially beneficial cancer treatment approach particularly over chemotherapy, which often lacks selectivity and can cause non-specific toxicity. Despite significant progress pre-clinically with respect to both enhanced targeting and expression in a tumor-selective manner several hurdles still prevent success in the clinic, including non-specific expression, low-efficiency delivery and biosafety. Various innovative genetic approaches are under development to reconstruct vectors/transgenes to make them safer and more effective. Utilizing cutting-edge delivery technologies, gene expression can now be targeted in a tissue- and organ-specific manner. With these advances, gene therapy is poised to become amenable for routine cancer therapy with potential to elevate this methodology as a first line therapy for neoplastic diseases. This review discusses recent advances in gene therapy and their impact on a pre-clinical and clinical level. PMID:25196387

  20. Gene therapy for hemophilia: past, present and future.

    PubMed

    George, Lindsey A; Fogarty, Patrick F

    2016-01-01

    After numerous preclinical studies demonstrated consistent success in large and small animal models, gene therapy has finally seen initial signs of clinically meaningful success. In a landmark study, Nathwani and colleagues reported sustained factor (F)IX expression in individuals with severe hemophilia B following adeno-associated virus (AAV)-mediated in vivo FIX gene transfer. As the next possible treatment-changing paradigm in hemophilia care, gene therapy may provide patients with sufficient hemostatic improvement to achieve the World Federation of Hemophilia's aspirational goal of "integration of opportunities in all aspects of life… equivalent to someone without a bleeding disorder." Although promising momentum supports the potential of gene therapy to replace protein-based therapeutics for hemophilia, several obstacles remain. The largest challenges appear to be overcoming the cellular immune responses to the AAV capsid; preexisting AAV neutralizing antibodies, which immediately exclude approximately 50% of the target population; and the ability to scale-up vector manufacturing for widespread applicability. Additional obstacles specific to hemophilia A (HA) include designing a vector cassette to accommodate a larger cDNA; avoiding development of inhibitory antibodies; and, perhaps the greatest difficulty to overcome, ensuring adequate expression efficiency. This review discusses the relevance of gene therapy to the hemophilia disease state, previous research progress, the current landscape of clinical trials, and considerations for promoting the future availability of gene therapy for hemophilia. PMID:26805907

  1. Retinal transduction profiles by high-capacity viral vectors

    PubMed Central

    Puppo, Agostina; Cesi, Giulia; Marrocco, Elena; Piccolo, Pasquale; Jacca, Sarah; Shayakhmetov, Dmitry M.; Parks, Robin J.; Davidson, Beverly L.; Colloca, Stefano; Brunetti-Pierri, Nicola; Ng, Philip; Donofrio, Gaetano; Auricchio, Alberto

    2014-01-01

    Retinal gene therapy with adeno-associated viral (AAV) vectors is safe and effective in humans. However, the limited cargo capacity of AAV prevents their use for therapy of those inherited retinopathies (IRs) due to mutations in large (>5kb) genes. Viral vectors derived from Adenovirus (Ad), Lentivirus (LV) and Herpesvirus (HV) can package large DNA sequences but do not target efficiently retinal photoreceptors (PRs) where the majority of genes responsible for IRs are expressed. Here, we have evaluated the mouse retinal transduction profiles of vectors derived from 16 different Ad serotypes, 7 LV pseudotypes, and from a bovine HV. Most of the vectors tested transduced efficiently the retinal pigment epithelium (RPE). We found that LV-GP64 tends to transduce more PRs than the canonical LV-VSVG albeit this was restricted to a narrow region. We observed more extensive PR transduction with HdAd1, 2 and 5/F35++ than with LV, although none of them outperformed the canonical HdAd5 or matched the extension of PR transduction achieved with AAV2/8. PMID:24989814

  2. The "eyes absent" (eya) gene in the eye-bearing hydrozoan jellyfish Cladonema radiatum: conservation of the retinal determination network.

    PubMed

    Graziussi, Daria Federica; Suga, Hiroshi; Schmid, Volker; Gehring, Walter Jakob

    2012-06-01

    Eyes absent (Eya) is a member of the Retinal Determination Gene Network (RDGN), a set of genes responsible for eye specification in Drosophila. Eya is a dual function protein, working as a transcription factor in the nucleus and as a tyrosine phosphatase in the cytoplasm. It had been shown that Pax and Six family genes, main components of the RDGN, are present in the hydrozoan Cladonema radiatum and that they are expressed in the eye. However, nothing had been known about the Eya family in hydrozoan jellyfish. Here we report the presence of an Eya homologue (CrEya) in Cladonema. Real-time PCR analysis and in situ hybridization showed that CrEya is expressed in the eye. Furthermore, the comprehensive survey of eukaryote genomes revealed that the acquisition of the N-terminal transactivation domain, including the EYA Domain 2 and its adjacent sequence shared by all eumetazoans, happened early in evolution, before the separation of Cnidaria and Bilateria. Our results uncover the evolution of the two domains and show a conservation of the expression pattern of the Eya gene between Cnidaria and Bilateria, which, together with previous data, supports the hypothesis of the monophyletic origin of metazoans eyes. We additionally show that CrEya is also expressed in the oocytes, where two other members of the RDGN, CrPaxB, and Six4/5-Cr, are known to be expressed. These data suggest that several members of the RDGN have begun to be localized also into the different context of egg development early in the course of metazoan evolution. PMID:22821862

  3. Construction of a YAC contig in the region of three retinal degeneration genes in 11q13

    SciTech Connect

    Gerhard, J.; Wang, J.

    1994-09-01

    We have previously isolated a large number of bacteriophage clones specific for human chromosome 11. Seventy-two clones map to distal 11q13, a region haboring a number of human disease genes. Among them are genes for Best macular degeneration (BMD), Usher`s syndrome type 1B, autosomal dominant neovascular inflammatory vitreoretinopathy (ADNIV) and a form of Bardet-Biedl syndrome; all diseases involve retinal degenerations. From the genetic mapping it is clear the BMD and Bardet-Biedl syndrome are located in the proximal portion of the band, while Usher`s syndrome 1B and ADNIV are in the distal portion of 11q13. As the first step towards the cloning of the latter two disease genes, we set out to isolate this region of the chromosome as yeast artificial chromosomes (YACs). The 72 clones, as well as two transcribed genes, were assigned into 4 segregation groups with radiation-reduced somatic cell hybrids. We have shown previously that this high probe density can result in the development of large YAC contigs. We chose to use two complementing strategies to screen three different YAC libraries. The two strategies are: (1) the generation of Alu-primed products from the bacteriophage clones that are then used as probes against filters from individual YAC library pools; (2) the sequencing of the bacteriophage clones, STS development and screening YAC libraries by the method of Green and Olson (1990). The former has the advantage of speed, while the latter of specificity. We have identified a total of 140 YACs from 50 screens. Approximately 50% of the markers are already in small contigs. The largest contig has 10 markers and is {approximately}1 mbp. This approach results in fairly rapid development of YAC contigs without additional application of labor-intensive, locus-specific manipulation. We expect to complete the contig within a year.

  4. Personalized therapeutic strategies for patients with retinitis pigmentosa

    PubMed Central

    Zheng, Andrew; Li, Yao

    2015-01-01

    Introduction Retinitis pigmentosa (RP) encompasses many different hereditary retinal degenerations that are caused by a vast array of different gene mutations and have highly variable disease presentations and severities. This heterogeneity poses a significant therapeutic challenge, although an answer may eventually be found through two recent innovations: induced pluripotent stem cells (iPSCs) and clustered regularly interspaced short palindromic repeats (CRISPR)/Cas genome editing. Areas covered This review discusses the wide-ranging applications of iPSCs and CRISPR–including disease modelling, diagnostics and therapeutics – with an ultimate view towards understanding how these two technologies can come together to address disease heterogeneity and orphan genes in a novel personalized medicine platform. An extensive literature search was conducted in PubMed and Google Scholar, with a particular focus on high-impact research published within the last 1 – 2 years and centered broadly on the subjects of retinal gene therapy, iPSC-derived outer retina cells, stem cell transplantation and CRISPR/Cas gene editing. Expert opinion For the retinal pigment epithelium, autologous transplantation of gene-corrected grafts derived from iPSCs may well be technically feasible in the near future. Photoreceptor transplantation faces more significant unresolved technical challenges but remains an achievable, if more distant, goal given the rapid pace of advancements in the field. PMID:25613576

  5. Immunostimulatory Gene Therapy Using Oncolytic Viruses as Vehicles

    PubMed Central

    Loskog, Angelica

    2015-01-01

    Immunostimulatory gene therapy has been developed during the past twenty years. The aim of immunostimulatory gene therapy is to tilt the suppressive tumor microenvironment to promote anti-tumor immunity. Hence, like a Trojan horse, the gene vehicle can carry warriors and weapons into enemy territory to combat the tumor from within. The most promising immune stimulators are those activating and sustaining Th1 responses, but even if potent effects were seen in preclinical models, many clinical trials failed to show objective responses in cancer patients. However, with new tools to control ongoing immunosuppression in cancer patients, immunostimulatory gene therapy is now emerging as an interesting option. In parallel, oncolytic viruses have been shown to be safe in patients. To prolong immune stimulation and to increase efficacy, these two fields are now merging and oncolytic viruses are armed with immunostimulatory transgenes. These novel agents are racing towards approval as established cancer immunotherapeutics. PMID:26561829

  6. Gene Therapy for the Treatment of Neurological Disorders: Metabolic Disorders

    PubMed Central

    Gessler, Dominic J.; Gao, Guangping

    2016-01-01

    Metabolic disorders comprise a large group of heterogeneous diseases ranging from very prevalent diseases such as diabetes mellitus to rare genetic disorders like Canavan Disease. Whether either of these diseases is amendable by gene therapy depends to a large degree on the knowledge of their pathomechanism, availability of the therapeutic gene, vector selection, and availability of suitable animal models. In this book chapter, we review three metabolic disorders of the central nervous system (CNS; Canavan Disease, Niemann–Pick disease and Phenylketonuria) to give examples for primary and secondary metabolic disorders of the brain and the attempts that have been made to use adeno-associated virus (AAV) based gene therapy for treatment. Finally, we highlight commonalities and obstacles in the development of gene therapy for metabolic disorders of the CNS exemplified by those three diseases. PMID:26611604

  7. Immunostimulatory Gene Therapy Using Oncolytic Viruses as Vehicles.

    PubMed

    Loskog, Angelica

    2015-11-01

    Immunostimulatory gene therapy has been developed during the past twenty years. The aim of immunostimulatory gene therapy is to tilt the suppressive tumor microenvironment to promote anti-tumor immunity. Hence, like a Trojan horse, the gene vehicle can carry warriors and weapons into enemy territory to combat the tumor from within. The most promising immune stimulators are those activating and sustaining Th1 responses, but even if potent effects were seen in preclinical models, many clinical trials failed to show objective responses in cancer patients. However, with new tools to control ongoing immunosuppression in cancer patients, immunostimulatory gene therapy is now emerging as an interesting option. In parallel, oncolytic viruses have been shown to be safe in patients. To prolong immune stimulation and to increase efficacy, these two fields are now merging and oncolytic viruses are armed with immunostimulatory transgenes. These novel agents are racing towards approval as established cancer immunotherapeutics. PMID:26561829

  8. Retinal abnormalities in β-thalassemia major.

    PubMed

    Bhoiwala, Devang L; Dunaief, Joshua L

    2016-01-01

    Patients with beta (β)-thalassemia (β-TM: β-thalassemia major, β-TI: β-thalassemia intermedia) have a variety of complications that may affect all organs, including the eye. Ocular abnormalities include retinal pigment epithelial degeneration, angioid streaks, venous tortuosity, night blindness, visual field defects, decreased visual acuity, color vision abnormalities, and acute visual loss. Patients with β-thalassemia major are transfusion dependent and require iron chelation therapy to survive. Retinal degeneration may result from either retinal iron accumulation from transfusion-induced iron overload or retinal toxicity induced by iron chelation therapy. Some who were never treated with iron chelation therapy exhibited retinopathy, and others receiving iron chelation therapy had chelator-induced retinopathy. We will focus on retinal abnormalities present in individuals with β-thalassemia major viewed in light of new findings on the mechanisms and manifestations of retinal iron toxicity. PMID:26325202

  9. Recent trends in the gene therapy of β-thalassemia

    PubMed Central

    Finotti, Alessia; Breda, Laura; Lederer, Carsten W; Bianchi, Nicoletta; Zuccato, Cristina; Kleanthous, Marina; Rivella, Stefano; Gambari, Roberto

    2015-01-01

    The β-thalassemias are a group of hereditary hematological diseases caused by over 300 mutations of the adult β-globin gene. Together with sickle cell anemia, thalassemia syndromes are among the most impactful diseases in developing countries, in which the lack of genetic counseling and prenatal diagnosis have contributed to the maintenance of a very high frequency of these genetic diseases in the population. Gene therapy for β-thalassemia has recently seen steadily accelerating progress and has reached a crossroads in its development. Presently, data from past and ongoing clinical trials guide the design of further clinical and preclinical studies based on gene augmentation, while fundamental insights into globin switching and new technology developments have inspired the investigation of novel gene-therapy approaches. Moreover, human erythropoietic stem cells from β-thalassemia patients have been the cellular targets of choice to date whereas future gene-therapy studies might increasingly draw on induced pluripotent stem cells. Herein, we summarize the most significant developments in β-thalassemia gene therapy over the last decade, with a strong emphasis on the most recent findings, for β-thalassemia model systems; for β-, γ-, and anti-sickling β-globin gene addition and combinatorial approaches including the latest results of clinical trials; and for novel approaches, such as transgene-mediated activation of γ-globin and genome editing using designer nucleases. PMID:25737641

  10. Gene therapy for the treatment of cystic fibrosis.

    PubMed

    Burney, Tabinda J; Davies, Jane C

    2012-01-01

    Gene therapy is being developed as a novel treatment for cystic fibrosis (CF), a condition that has hitherto been widely-researched yet for which no treatment exists that halts the progression of lung disease. Gene therapy involves the transfer of correct copies of cystic fibrosis transmembrane conductance regulator (CFTR) DNA to the epithelial cells in the airways. The cloning of the CFTR gene in 1989 led to proof-of-principle studies of CFTR gene transfer in vitro and in animal models. The earliest clinical trials in CF patients were conducted in 1993 and used viral and non-viral gene transfer agents in both the nasal and bronchial airway epithelium. To date, studies have focused largely on molecular or bioelectric (chloride secretion) outcome measures, many demonstrating evidence of CFTR expression, but few have attempted to achieve clinical efficacy. As CF is a lifelong disease, turnover of the airway epithelium necessitates repeat administration. To date, this has been difficult to achieve with viral gene transfer agents due to host recognition leading to loss of expression. The UK Cystic Fibrosis Gene Therapy Consortium (Imperial College London, University of Edinburgh and University of Oxford) is currently working on a large and ambitious program to establish the clinical benefits of CF gene therapy. Wave 1, which has reached the clinic, uses a non-viral vector. A single-dose safety trial is nearing completion and a multi-dose clinical trial is shortly due to start; this will be powered for clinically-relevant changes. Wave 2, more futuristically, will look at the potential of lentiviruses, which have long-lasting expression. This review will summarize the current status of translational research in CF gene therapy. PMID:23776378

  11. Advances in gene therapy for muscular dystrophies

    PubMed Central

    Abdul-Razak, Hayder; Malerba, Alberto; Dickson, George

    2016-01-01

    Duchenne muscular dystrophy (DMD) is a recessive lethal inherited muscular dystrophy caused by mutations in the gene encoding dystrophin, a protein required for muscle fibre integrity. So far, many approaches have been tested from the traditional gene addition to newer advanced approaches based on manipulation of the cellular machinery either at the gene transcription, mRNA processing or translation levels. Unfortunately, despite all these efforts, no efficient treatments for DMD are currently available. In this review, we highlight the most advanced therapeutic strategies under investigation as potential DMD treatments. PMID:27594988

  12. Advances in gene therapy for muscular dystrophies.

    PubMed

    Abdul-Razak, Hayder; Malerba, Alberto; Dickson, George

    2016-01-01

    Duchenne muscular dystrophy (DMD) is a recessive lethal inherited muscular dystrophy caused by mutations in the gene encoding dystrophin, a protein required for muscle fibre integrity. So far, many approaches have been tested from the traditional gene addition to newer advanced approaches based on manipulation of the cellular machinery either at the gene transcription, mRNA processing or translation levels. Unfortunately, despite all these efforts, no efficient treatments for DMD are currently available. In this review, we highlight the most advanced therapeutic strategies under investigation as potential DMD treatments. PMID:27594988

  13. Gene therapy for the prevention of vein graft disease

    PubMed Central

    Southerland, Kevin W.; Frazier, Sarah B.; Bowles, Dawn E.; Milano, Carmelo A.; Kontos, Christopher D.

    2013-01-01

    Ischemic cardiovascular disease remains the leading cause of death worldwide. Despite advances in the medical management of atherosclerosis over the past several decades, many patients require arterial revascularization to reduce mortality and alleviate ischemic symptoms. Technological advancements have led to dramatic increases in the use of percutaneous and endovascular approaches, yet surgical revascularization (bypass surgery) with autologous vein grafts remains a mainstay of therapy for both coronary and peripheral artery disease. Although bypass surgery is highly efficacious in the short-term, long-term outcomes are limited by relatively high failure rates as a result of intimal hyperplasia, which is a common feature of vein graft disease. The supply of native veins is limited, and many individuals require multiple grafts and repeat procedures. The need to prevent vein graft failure has led to great interest in gene therapy approaches to this problem. Bypass grafting presents an ideal opportunity for gene therapy, as surgically harvested vein grafts can be treated with gene delivery vectors ex vivo, thereby maximizing gene delivery while minimizing the potential for systemic toxicity and targeting the pathogenesis of vein graft disease at its onset. Here we will review the pathogenesis of vein graft disease and discuss vector delivery strategies and potential molecular targets for its prevention. We will summarize the preclinical and clinical literature on gene therapy in vein grafting and discuss additional considerations for future therapies to prevent vein graft disease. PMID:23274305

  14. 77 FR 71194 - Draft Guidance for Industry: Preclinical Assessment of Investigational Cellular and Gene Therapy...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-29

    ... Investigational Cellular and Gene Therapy Products; Availability AGENCY: Food and Drug Administration, HHS. ACTION... document entitled ``Guidance for Industry: Preclinical Assessment of Investigational Cellular and Gene... for Biologics Research and Evaluation (CBER), Office of Cellular, Tissue, and Gene Therapies...

  15. Transcriptional targeting of tumor endothelial cells for gene therapy

    PubMed Central

    Dong, Zhihong; Nör, Jacques E.

    2009-01-01

    It is well known that angiogenesis plays a critical role in the pathobiology of tumors. Recent clinical trials have shown that inhibition of angiogenesis can be an effective therapeutic strategy for patients with cancer. However, one of the outstanding issues in anti-angiogenic treatment for cancer is the development of toxicities related to off-target effects of drugs. Transcriptional targeting of tumor endothelial cells involves the use of specific promoters for selective expression of therapeutic genes in the endothelial cells lining the blood vessels of tumors. Recently, several genes that are expressed specifically in tumor-associated endothelial cells have been identified and characterized. These discoveries have enhanced the prospectus of transcriptionaly targeting tumor endothelial cells for cancer gene therapy. In this manuscript, we review the promoters, vectors, and therapeutic genes that have been used for transcriptional targeting of tumor endothelial cells, and discuss the prospects of such approaches for cancer gene therapy. PMID:19393703

  16. Microneedles As a Delivery System for Gene Therapy

    PubMed Central

    Chen, Wei; Li, Hui; Shi, De; Liu, Zhenguo; Yuan, Weien

    2016-01-01

    Gene delivery systems can be divided to two major types: vector-based (either viral vector or non-viral vector) and physical delivery technologies. Many physical carriers, such as electroporation, gene gun, ultrasound start to be proved to have the potential to enable gene therapy. A relatively new physical delivery technology for gene delivery consists of microneedles (MNs), which has been studied in many fields and for many molecule types and indications. Microneedles can penetrate the stratum corneum, which is the main barrier for drug delivery through the skin with ease of administration and without significant pain. Many different kinds of MNs, such as metal MNs, coated MNs, dissolving MNs have turned out to be promising in gene delivery. In this review, we discussed the potential as well as the challenges of utilizing MNs to deliver nucleic acids for gene therapy. We also proposed that a combination of MNs and other gene delivery approaches may lead to a better delivery system for gene therapy. PMID:27303298

  17. Microneedles As a Delivery System for Gene Therapy.

    PubMed

    Chen, Wei; Li, Hui; Shi, De; Liu, Zhenguo; Yuan, Weien

    2016-01-01

    Gene delivery systems can be divided to two major types: vector-based (either viral vector or non-viral vector) and physical delivery technologies. Many physical carriers, such as electroporation, gene gun, ultrasound start to be proved to have the potential to enable gene therapy. A relatively new physical delivery technology for gene delivery consists of microneedles (MNs), which has been studied in many fields and for many molecule types and indications. Microneedles can penetrate the stratum corneum, which is the main barrier for drug delivery through the skin with ease of administration and without significant pain. Many different kinds of MNs, such as metal MNs, coated MNs, dissolving MNs have turned out to be promising in gene delivery. In this review, we discussed the potential as well as the challenges of utilizing MNs to deliver nucleic acids for gene therapy. We also proposed that a combination of MNs and other gene delivery approaches may lead to a better delivery system for gene therapy. PMID:27303298

  18. Retinal prosthetics, optogenetics, and chemical photoswitches.

    PubMed

    Marc, Robert; Pfeiffer, Rebecca; Jones, Bryan

    2014-10-15

    Three technologies have emerged as therapies to restore light sensing to profoundly blind patients suffering from late-stage retinal degenerations: (1) retinal prosthetics, (2) optogenetics, and (3) chemical photoswitches. Prosthetics are the most mature and the only approach in clinical practice. Prosthetic implants require complex surgical intervention and provide only limited visual resolution but can potentially restore navigational ability to many blind patients. Optogenetics uses viral delivery of type 1 opsin genes from prokaryotes or eukaryote algae to restore light responses in survivor neurons. Targeting and expression remain major problems, but are potentially soluble. Importantly, optogenetics could provide the ultimate in high-resolution vision due to the long persistence of gene expression achieved in animal models. Nevertheless, optogenetics remains challenging to implement in human eyes with large volumes, complex disease progression, and physical barriers to viral penetration. Now, a new generation of photochromic ligands or chemical photoswitches (azobenzene-quaternary ammonium derivatives) can be injected into a degenerated mouse eye and, in minutes to hours, activate light responses in neurons. These photoswitches offer the potential for rapidly and reversibly screening the vision restoration expected in an individual patient. Chemical photoswitch variants that persist in the cell membrane could make them a simple therapy of choice, with resolution and sensitivity equivalent to optogenetics approaches. A major complexity in treating retinal degenerations is retinal remodeling: pathologic network rewiring, molecular reprogramming, and cell death that compromise signaling in the surviving retina. Remodeling forces a choice between upstream and downstream targeting, each engaging different benefits and defects. Prosthetics and optogenetics can be implemented in either mode, but the use of chemical photoswitches is currently limited to downstream

  19. Retinal Prosthetics, Optogenetics, and Chemical Photoswitches

    PubMed Central

    2015-01-01

    Three technologies have emerged as therapies to restore light sensing to profoundly blind patients suffering from late-stage retinal degenerations: (1) retinal prosthetics, (2) optogenetics, and (3) chemical photoswitches. Prosthetics are the most mature and the only approach in clinical practice. Prosthetic implants require complex surgical intervention and provide only limited visual resolution but can potentially restore navigational ability to many blind patients. Optogenetics uses viral delivery of type 1 opsin genes from prokaryotes or eukaryote algae to restore light responses in survivor neurons. Targeting and expression remain major problems, but are potentially soluble. Importantly, optogenetics could provide the ultimate in high-resolution vision due to the long persistence of gene expression achieved in animal models. Nevertheless, optogenetics remains challenging to implement in human eyes with large volumes, complex disease progression, and physical barriers to viral penetration. Now, a new generation of photochromic ligands or chemical photoswitches (azobenzene-quaternary ammonium derivatives) can be injected into a degenerated mouse eye and, in minutes to hours, activate light responses in neurons. These photoswitches offer the potential for rapidly and reversibly screening the vision restoration expected in an individual patient. Chemical photoswitch variants that persist in the cell membrane could make them a simple therapy of choice, with resolution and sensitivity equivalent to optogenetics approaches. A major complexity in treating retinal degenerations is retinal remodeling: pathologic network rewiring, molecular reprogramming, and cell death that compromise signaling in the surviving retina. Remodeling forces a choice between upstream and downstream targeting, each engaging different benefits and defects. Prosthetics and optogenetics can be implemented in either mode, but the use of chemical photoswitches is currently limited to downstream

  20. Transcriptionally targeted gene therapy to detect and treat cancer

    PubMed Central

    Wu, Lily; Johnson, Mai; Sato, Makoto

    2010-01-01

    The greatest challenge in cancer treatment is to achieve the highest levels of specificity and efficacy. Cancer gene therapy could be designed specifically to express therapeutic genes to induce cancer cell destruction. Cancer-specific promoters are useful tools to accomplish targeted expression; however, high levels of gene expression are needed to achieve therapeutic efficacy. Incorporating an imaging reporter gene in tandem with the therapeutic gene will allow tangible proof of principle that gene expression occurs at the correct location and at a sufficient level. Gene-based imaging can advance cancer detection and diagnosis. By combining the cancer-targeted imaging and therapeutic strategies, the exciting prospect of a ‘one-two punch’ to find hidden, disseminated cancer cells and destroy them simultaneously can potentially be realized. PMID:14557054

  1. Mesenchymal stem cell-based gene therapy for erectile dysfunction.

    PubMed

    Kim, J H; Lee, H J; Song, Y S

    2016-05-01

    Despite the overwhelming success of PDE5 inhibitor (PDE5I), the demand for novel pharmacotherapeutic and surgical options for ED continues to rise owing to the increased proportion of elderly individuals in the population, in addition to the growing percentage of ED patients who do not respond to PDE5I. Surgical treatment of ED is associated with many complications, thus warranting the need for nonsurgical therapies. Moreover, none of the above-mentioned treatments essentially corrects, cures or prevents ED. Although gene therapy is a promising option, many challenges and obstacles such as local inflammatory response and random transgene expression, in addition to other safety issues, limit its use at the clinical level. The use of stem cell therapy alone also has many shortcomings. To overcome these inadequacies, many scientists and clinicians are investigating new gene and stem cell therapies. PMID:26888355

  2. [Is a gene therapy for diabetic syndromes foreseeable?].

    PubMed

    Assan, R; Clauser, E; Larger, E

    1994-01-01

    The concepts and methods of gene therapy are summarized in order to assess a possible implication in the treatment of diabetes mellitus. Gene therapy requires identification of the critical genetic defect and then the preparation and introduction of the therapeutic transgene, with an appropriate targeting and a strong regulated expression. The bases of the different human diabetic syndromes are reviewed in their present state of knowledge: they are mostly clarified in the case of MODY, extreme insulin resistance syndromes, and some mitochondrial diabetic syndromes; but still obscure in the case of Type 2 and Type 1 diabetic syndromes. Substantial contributions to the understanding of the pathophysiology of diabetes have been brought by transgenic animal models. Gene therapy of human diabetic syndromes may become available, in an undetermined future, particularly under the forms of insulin secreting transgenic "organoïds". Such treatments should be proportionate to the intrinsic severity of the candidate diseases and carefully screened for safety. PMID:8001711

  3. Adeno-associated virus for cystic fibrosis gene therapy.

    PubMed

    Martini, S V; Rocco, P R M; Morales, M M

    2011-11-01

    Gene therapy is an alternative treatment for genetic lung disease, especially monogenic disorders such as cystic fibrosis. Cystic fibrosis is a severe autosomal recessive disease affecting one in 2500 live births in the white population, caused by mutation of the cystic fibrosis transmembrane conductance regulator (CFTR). The disease is classically characterized by pancreatic enzyme insufficiency, an increased concentration of chloride in sweat, and varying severity of chronic obstructive lung disease. Currently, the greatest challenge for gene therapy is finding an ideal vector to deliver the transgene (CFTR) to the affected organ (lung). Adeno-associated virus is the most promising viral vector system for the treatment of respiratory disease because it has natural tropism for airway epithelial cells and does not cause any human disease. This review focuses on the basic properties of adeno-associated virus and its use as a vector for cystic fibrosis gene therapy. PMID:21952739

  4. Regulation of Cell and Gene Therapy Medicinal Products in Taiwan.

    PubMed

    Lin, Yi-Chu; Wang, Po-Yu; Tsai, Shih-Chih; Lin, Chien-Liang; Tai, Hsuen-Yung; Lo, Chi-Fang; Wu, Shiow-Ing; Chiang, Yu-Mei; Liu, Li-Ling

    2015-01-01

    Owing to the rapid and mature development of emerging biotechnology in the fields of cell culture, cell preservation, and recombinant DNA technology, more and more cell or gene medicinal therapy products have been approved for marketing, to treat serious diseases which have been challenging to treat with current medical practice or medicine. This chapter will briefly introduce the Taiwan Food and Drug Administration (TFDA) and elaborate regulation of cell and gene therapy medicinal products in Taiwan, including regulatory history evolution, current regulatory framework, application and review procedures, and relevant jurisdictional issues. Under the promise of quality, safety, and efficacy of medicinal products, it is expected the regulation and environment will be more flexible, streamlining the process of the marketing approval of new emerging cell or gene therapy medicinal products and providing diverse treatment options for physicians and patients. PMID:26374219

  5. Large Animal Models of Neurological Disorders for Gene Therapy

    PubMed Central

    Gagliardi, Christine; Bunnell, Bruce A.

    2009-01-01

    The development of therapeutic interventions for genetic disorders and diseases that affect the central nervous system (CNS) has proven challenging. There has been significant progress in the development of gene therapy strategies in murine models of human disease, but gene therapy outcomes in these models do not always translate to the human setting. Therefore, large animal models are crucial to the development of diagnostics, treatments, and eventual cures for debilitating neurological disorders. This review focuses on the description of large animal models of neurological diseases such as lysosomal storage diseases, Parkinson’s disease, Huntington’s disease, and neuroAIDS. The review also describes the contributions of these models to progress in gene therapy research. PMID:19293458

  6. Improving the management of Inherited Retinal Dystrophies by targeted sequencing of a population-specific gene panel.

    PubMed

    Bravo-Gil, Nereida; Méndez-Vidal, Cristina; Romero-Pérez, Laura; González-del Pozo, María; Rodríguez-de la Rúa, Enrique; Dopazo, Joaquín; Borrego, Salud; Antiñolo, Guillermo

    2016-01-01

    Next-generation sequencing (NGS) has overcome important limitations to the molecular diagnosis of Inherited Retinal Dystrophies (IRD) such as the high clinical and genetic heterogeneity and the overlapping phenotypes. The purpose of this study was the identification of the genetic defect in 32 Spanish families with different forms of IRD. With that aim, we implemented a custom NGS panel comprising 64 IRD-associated genes in our population, and three disease-associated intronic regions. A total of 37 pathogenic mutations (14 novels) were found in 73% of IRD patients ranging from 50% for autosomal dominant cases, 75% for syndromic cases, 83% for autosomal recessive cases, and 100% for X-linked cases. Additionally, unexpected phenotype-genotype correlations were found in 6 probands, which led to the refinement of their clinical diagnoses. Furthermore, intra- and interfamilial phenotypic variability was observed in two cases. Moreover, two cases unsuccessfully analysed by exome sequencing were resolved by applying this panel. Our results demonstrate that this hypothesis-free approach based on frequently mutated, population-specific loci is highly cost-efficient for the routine diagnosis of this heterogeneous condition and allows the unbiased analysis of a miscellaneous cohort. The molecular information found here has aid clinical diagnosis and has improved genetic counselling and patient management. PMID:27032803

  7. Cerebro-retinal microangiopathy with calcifications and cysts due to recessive mutations in the CTC1 gene.

    PubMed

    Bisserbe, A; Tertian, G; Buffet, C; Turhan, A; Lambotte, O; Nasser, G; Alvin, P; Tardieu, M; Riant, F; Bergametti, F; Tournier-Lasserve, E; Denier, C

    2015-05-01

    Cerebro-retinal microangiopathy with calcifications and cysts (CRMCC) or Coats plus syndrome is a pleiotropic disorder affecting the eyes, brain, bone and gastrointestinal tract. Its primary pathogenesis involves small vessel obliterative microangiopathy. Recently, autosomal recessively inherited mutations in CTC1 have been reported in CRMCC patients. We herein report an adolescent referred to our hospital following new seizures in a context of an undefined multisystem disorder. Cerebral imaging disclosed asymmetrical leukopathy, intracranial calcifications and cysts. In addition, he presented other typical CRMCC features i.e. a history of intrauterine growth retardation, skeletal demineralization and osteopenia, bilateral exudative vitreo-retinopathy reminiscent of Coats disease, recurrent gastrointestinal hemorrhages secondary to watermelon stomach and variceal bleeding of the esophagus due to idiopathic portal hypertension and telangiectatic and angiodysplasic changes in the small intestine and colon, and anemia due to recurrent bleeding and bone marrow abnormalities. The patient was diagnosed with Coats plus syndrome. CTC1 gene screening confirmed the diagnosis with the identification of heterozygous deleterious mutations. CRMCC due to CTC1 mutations has a broad clinical expressivity. Our case report illustrates the main possible associated phenotypes and their complications, demonstrating the need for a careful etiological search in order to initiate appropriate therapeutic and preventive measures. PMID:25843205

  8. Improving the management of Inherited Retinal Dystrophies by targeted sequencing of a population-specific gene panel

    PubMed Central

    Bravo-Gil, Nereida; Méndez-Vidal, Cristina; Romero-Pérez, Laura; González-del Pozo, María; Rodríguez-de la Rúa, Enrique; Dopazo, Joaquín; Borrego, Salud; Antiñolo, Guillermo

    2016-01-01

    Next-generation sequencing (NGS) has overcome important limitations to the molecular diagnosis of Inherited Retinal Dystrophies (IRD) such as the high clinical and genetic heterogeneity and the overlapping phenotypes. The purpose of this study was the identification of the genetic defect in 32 Spanish families with different forms of IRD. With that aim, we implemented a custom NGS panel comprising 64 IRD-associated genes in our population, and three disease-associated intronic regions. A total of 37 pathogenic mutations (14 novels) were found in 73% of IRD patients ranging from 50% for autosomal dominant cases, 75% for syndromic cases, 83% for autosomal recessive cases, and 100% for X-linked cases. Additionally, unexpected phenotype-genotype correlations were found in 6 probands, which led to the refinement of their clinical diagnoses. Furthermore, intra- and interfamilial phenotypic variability was observed in two cases. Moreover, two cases unsuccessfully analysed by exome sequencing were resolved by applying this panel. Our results demonstrate that this hypothesis-free approach based on frequently mutated, population-specific loci is highly cost-efficient for the routine diagnosis of this heterogeneous condition and allows the unbiased analysis of a miscellaneous cohort. The molecular information found here has aid clinical diagnosis and has improved genetic counselling and patient management. PMID:27032803

  9. Antisense Gene Silencing: Therapy for Neurodegenerative Disorders?

    PubMed Central

    Nielsen, Troels T.; Nielsen, Jørgen E.

    2013-01-01

    Since the first reports that double-stranded RNAs can efficiently silence gene expression in C. elegans, the technology of RNA interference (RNAi) has been intensively exploited as an experimental tool to study gene function. With the subsequent discovery that RNAi could also be applied to mammalian cells, the technology of RNAi expanded from being a valuable experimental tool to being an applicable method for gene-specific therapeutic regulation, and much effort has been put into further refinement of the technique. This review will focus on how RNAi has developed over the years and how the technique is exploited in a pre-clinical and clinical perspective in relation to neurodegenerative disorders. PMID:24705213

  10. Technology evaluation: VEGF165 gene therapy, Valentis Inc.

    PubMed

    Morse, M A

    2001-02-01

    Valentis Inc, formerly GeneMedicine, is developing a vascular endothelial growth factor (VEGF165) non-viral gene therapy using its proprietary PINC polymer for plasmid condensation. Two physician-initiated phase II angioplasty trials are ongoing, one for treating peripheral vascular disease and one for treating coronary artery disease [281714], [347153]. In February 2000, the trials were expected to be completed in the fourth quarter of 2000 [356225]; however, in October 2000, it was reported that the trial for peripheral vascular disease would be completed in the first quarter of 2001 [385232]. In March 2000, Valentis initiated a trial incorporating Valentis's DOTMA-based cationic lipid gene delivery system and the VEGF165 gene with Eurogene's local collar-reservoir delivery device. The trial is designed to demonstrate that the VEGF165 gene, delivered locally to the outside surface of a blood vessel, will transfect and express in the smooth muscle cells of the vessel wall [360683]. In March 1999, Valentis was awarded with a Phase II SBIR grant of $686,260. The aim of grant was to advance the development of non-viral gene therapies for ischemia. Specifically, Valentis intended to select an optimal promoter to be used with the VEGF expression plasmid. Valentis also intended to evaluate the gene therapy system in a rabbit ischemia model and complete the necessary preclinical studies for submission of an IND [318137]. PMID:11249737

  11. Macrophage mediated PCI enhanced gene-directed enzyme prodrug therapy

    NASA Astrophysics Data System (ADS)

    Christie, Catherine E.; Zamora, Genesis; Kwon, Young J.; Berg, Kristian; Madsen, Steen J.; Hirschberg, Henry

    2015-03-01

    Photochemical internalization (PCI) is a photodynamic therapy-based approach for improving the delivery of macromolecules and genes into the cell cytosol. Prodrug activating gene therapy (suicide gene therapy) employing the transduction of the E. coli cytosine deaminase (CD) gene into tumor cells, is a promising method. Expression of this gene within the target cell produces an enzyme that converts the nontoxic prodrug, 5-FC, to the toxic metabolite, 5-fluorouracil (5-FU). 5-FC may be particularly suitable for brain tumors, because it can readily cross the bloodbrain barrier (BBB). In addition the bystander effect, where activated drug is exported from the transfected cancer cells into the tumor microenvironment, plays an important role by inhibiting growth of adjacent tumor cells. Tumor-associated macrophages (TAMs) are frequently found in and around glioblastomas. Monocytes or macrophages (Ma) loaded with drugs, nanoparticles or photosensitizers could therefore be used to target tumors by local synthesis of chemo attractive factors. The basic concept is to combine PCI, to enhance the ex vivo transfection of a suicide gene into Ma, employing specially designed core/shell NP as gene carrier.

  12. Challenges and Prospects for Alpha-1 Antitrypsin Deficiency Gene Therapy.

    PubMed

    Wozniak, Joanna; Wandtke, Tomasz; Kopinski, Piotr; Chorostowska-Wynimko, Joanna

    2015-11-01

    Alpha-1 antitrypsin (AAT) is a protease inhibitor belonging to the serpin family. A number of identified mutations in the SERPINA1 gene encoding this protein result in alpha-1 antitrypsin deficiency (AATD). A decrease in AAT serum concentration or reduced biological activity causes considerable risk of chronic respiratory and liver disorders. As a monogenic disease, AATD appears to be an attractive target for gene therapy, particularly for patients with pulmonary dysfunction, where augmentation of functional AAT levels in plasma might slow down respiratory disease development. The short AAT coding sequence and its activity in the extracellular matrix would enable an increase in systemic serum AAT production by cellular secretion. In vitro and in vivo experimental AAT gene transfer with gamma-retroviral, lentiviral, adenoviral, and adeno-associated viral (AAV) vectors has resulted in enhanced AAT serum levels and a promising safety profile. Human clinical trials using intramuscular viral transfer with AAV1 and AAV2 vectors of the AAT gene demonstrated its safety, but did not achieve a protective level of AAT >11 μM in serum. This review provides an in-depth critical analysis of current progress in AATD gene therapy based on viral gene transfer. The factors affecting transgene expression levels, such as site of administration, dose and type of vector, and activity of the immune system, are discussed further as crucial variables for optimizing the clinical effectiveness of gene therapy in AATD subjects. PMID:26413996

  13. Stem cells’ guided gene therapy of cancer: New frontier in personalized and targeted therapy

    PubMed Central

    Mavroudi, Maria; Zarogoulidis, Paul; Porpodis, Konstantinos; Kioumis, Ioannis; Lampaki, Sofia; Yarmus, Lonny; Malecki, Raf; Zarogoulidis, Konstantinos; Malecki, Marek

    2014-01-01

    Introduction Diagnosis and therapy of cancer remain to be the greatest challenges for all physicians working in clinical oncology and molecular medicine. The statistics speak for themselves with the grim reports of 1,638,910 men and women diagnosed with cancer and nearly 577,190 patients passed away due to cancer in the USA in 2012. For practicing clinicians, who treat patients suffering from advanced cancers with contemporary systemic therapies, the main challenge is to attain therapeutic efficacy, while minimizing side effects. Unfortunately, all contemporary systemic therapies cause side effects. In treated patients, these side effects may range from nausea to damaged tissues. In cancer survivors, the iatrogenic outcomes of systemic therapies may include genomic mutations and their consequences. Therefore, there is an urgent need for personalized and targeted therapies. Recently, we reviewed the current status of suicide gene therapy for cancer. Herein, we discuss the novel strategy: genetically engineered stem cells’ guided gene therapy. Review of therapeutic strategies in preclinical and clinical trials Stem cells have the unique potential for self renewal and differentiation. This potential is the primary reason for introducing them into medicine to regenerate injured or degenerated organs, as well as to rejuvenate aging tissues. Recent advances in genetic engineering and stem cell research have created the foundations for genetic engineering of stem cells as the vectors for delivery of therapeutic transgenes. Specifically in oncology, the stem cells are genetically engineered to deliver the cell suicide inducing genes selectively to the cancer cells only. Expression of the transgenes kills the cancer cells, while leaving healthy cells unaffected. Herein, we present various strategies to bioengineer suicide inducing genes and stem cell vectors. Moreover, we review results of the main preclinical studies and clinical trials. However, the main risk for

  14. Stem Cell Based Gene Therapy in Prostate Cancer

    PubMed Central

    Lee, Hong Jun; Song, Yun Seob

    2014-01-01

    Current prostate cancer treatment, especially hormone refractory cancer, may create profound iatrogenic outcomes because of the adverse effects of cytotoxic agents. Suicide gene therapy has been investigated for the substitute modality for current chemotherapy because it enables the treatment targeting the cancer cells. However the classic suicide gene therapy has several profound side effects, including immune-compromised due to viral vector. Recently, stem cells have been regarded as a new upgraded cellular vehicle or vector because of its homing effects. Suicide gene therapy using genetically engineered mesenchymal stem cells or neural stem cells has the advantage of being safe, because prodrug administration not only eliminates tumor cells but consequently kills the more resistant therapeutic stem cells as well. The attractiveness of prodrug cancer gene therapy by stem cells targeted to tumors lies in activating the prodrug directly within the tumor mass, thus avoiding systemic toxicity. Therapeutic achievements using stem cells in prostate cancer include the cytosine deaminase/5-fluorocytosine prodrug system, herpes simplex virus thymidine kinase/ganciclovir, carboxyl esterase/CPT11, and interferon-beta. The aim of this study is to review the stem cell therapy in prostate cancer including its proven mechanisms and also limitations. PMID:25121103

  15. Long-term and age-dependent restoration of visual function in a mouse model of CNGB3-associated achromatopsia following gene therapy.

    PubMed

    Carvalho, Livia S; Xu, Jianhua; Pearson, Rachael A; Smith, Alexander J; Bainbridge, James W; Morris, Lynsie M; Fliesler, Steven J; Ding, Xi-Qin; Ali, Robin R

    2011-08-15

    Mutations in the CNGB3 gene account for >50% of all known cases of achromatopsia. Although of early onset, its stationary character and the potential for rapid assessment of restoration of retinal function following therapy renders achromatopsia a very attractive candidate for gene therapy. Here we tested the efficacy of an rAAV2/8 vector containing a human cone arrestin promoter and a human CNGB3 cDNA in CNGB3 deficient mice. Following subretinal delivery of the vector, CNGB3 was detected in both M- and S-cones and resulted in increased levels of CNGA3, increased cone density and survival, improved cone outer segment structure and normal subcellular compartmentalization of cone opsins. Therapy also resulted in long-term improvement of retinal function, with restoration of cone ERG amplitudes of up to 90% of wild-type and a significant improvement in visual acuity. Remarkably, successful restoration of cone function was observed even when treatment was initiated at 6 months of age; however, restoration of normal visual acuity was only possible in younger animals (e.g. 2-4 weeks old). This study represents achievement of the most substantial restoration of visual function reported to date in an animal model of achromatopsia using a human gene construct, which has the potential to be utilized in clinical trials. PMID:21576125

  16. Long-term and age-dependent restoration of visual function in a mouse model of CNGB3-associated achromatopsia following gene therapy

    PubMed Central

    Carvalho, Livia S.; Xu, Jianhua; Pearson, Rachael A.; Smith, Alexander J.; Bainbridge, James W.; Morris, Lynsie M.; Fliesler, Steven J.; Ding, Xi-Qin; Ali, Robin R.

    2011-01-01

    Mutations in the CNGB3 gene account for >50% of all known cases of achromatopsia. Although of early onset, its stationary character and the potential for rapid assessment of restoration of retinal function following therapy renders achromatopsia a very attractive candidate for gene therapy. Here we tested the efficacy of an rAAV2/8 vector containing a human cone arrestin promoter and a human CNGB3 cDNA in CNGB3 deficient mice. Following subretinal delivery of the vector, CNGB3 was detected in both M- and S-cones and resulted in increased levels of CNGA3, increased cone density and survival, improved cone outer segment structure and normal subcellular compartmentalization of cone opsins. Therapy also resulted in long-term improvement of retinal function, with restoration of cone ERG amplitudes of up to 90% of wild-type and a significant improvement in visual acuity. Remarkably, successful restoration of cone function was observed even when treatment was initiated at 6 months of age; however, restoration of normal visual acuity was only possible in younger animals (e.g. 2–4 weeks old). This study represents achievement of the most substantial restoration of visual function reported to date in an animal model of achromatopsia using a human gene construct, which has the potential to be utilized in clinical trials. PMID:21576125

  17. Gene therapy, fundamental rights, and the mandates of public health.

    PubMed

    Lynch, John

    2004-01-01

    Recent and near-future developments in the field of molecular biology will make possible the treatment of genetic disease on an unprecedented scale. The potential applications of these developments implicate important public policy considerations. Among the questions that may arise is the constitutionality of a state-mandated program of gene therapy for the purpose of eradicating certain genetic diseases. Though controversial, precedents of public health jurisprudence suggest that such a program could survive constitutional scrutiny. This article provides an overview of gene therapy in the context of fundamental rights and the mandates of public health. PMID:15255004

  18. Pathogenic mechanisms and the prospect of gene therapy for choroideremia

    PubMed Central

    Dimopoulos, Ioannis S; Chan, Stephanie; MacLaren, Robert E

    2015-01-01

    Introduction Choroideremia is a rare, X-linked disorder recognized by its specific ocular phenotype as a progressive degenerative retinopathy resulting in blindness. New therapeutic approaches, primarily based on genetic mechanisms, have emerged that aim to prevent the progressive vision loss. Areas covered This article will review the research that has progressed incrementally over the past two decades from mapping to gene discovery, uncovering the presumed mechanisms triggering the retinopathy to preclinical testing of potential therapies. Expert opinion While still in an evaluative phase, the introduction of gene replacement as a potential therapy has been greeted with great enthusiasm by patients, advocacy groups and the medical community. PMID:26251765

  19. Activation of rhodopsin gene transcription in cultured retinal precursors of chicken embryo: role of Ca(2+) signaling and hyperpolarization-activated cation channels.

    PubMed

    Bernard, Marianne; Dejos, Camille; Bergès, Thierry; Régnacq, Matthieu; Voisin, Pierre

    2014-04-01

    This study reports that the spontaneous 50-fold activation of rhodopsin gene transcription, observed in cultured retinal precursors from 13-day chicken embryo, relies on a Ca(2+)-dependent mechanism. Activation of a transiently transfected rhodopsin promoter (luciferase reporter) in these cells was inhibited (60%) by cotransfection of a dominant-negative form of the cAMP-responsive element-binding protein. Both rhodopsin promoter activity and rhodopsin mRNA accumulation were blocked by Ca(2+)/calmodulin-dependent kinase II inhibitors, but not by protein kinase A inhibitors, suggesting a role of Ca(2+) rather than cAMP. This was confirmed by the inhibitory effect of general and T-type selective Ca(2+) channel blockers. Oscillations in Ca(2+) fluorescence (Fluo8) could be observed in 1/10 cells that activated the rhodopsin promoter (DsRed reporter). A robust and reversible inhibition of rhodopsin gene transcription by ZD7288 indicated a role of hyperpolarization-activated channels (HCN). Cellular localization and developmental expression of HCN1 were compatible with a role in the onset of rhodopsin gene transcription. Together, the data suggest that the spontaneous activation of rhodopsin gene transcription in cultured retinal precursors results from a signaling cascade that involves the pacemaker activity of HCN channels, the opening of voltage-gated Ca(2+)-channels, activation of Ca(2+)/calmodulin-dependent kinase II and phosphorylation of cAMP-responsive element-binding protein. Rhodopsin gene expression in cultured retinal precursors from chicken embryo relies on a Ca2+-dependent mechanism whereby hyperpolarization-activated cyclic nucleotide-gated channels (HCN) activate T-type voltage-dependent Ca2+ channels (VDCC) through membrane depolarization, causing calmodulin-dependent kinase II (CaMKII) to phosphorylate the cAMP-responsive element-binding protein (CREB) and leading to activation of rhodopsin gene transcription. Photoreceptor localization and development

  20. Current gene therapy using viral vectors for chronic pain.

    PubMed

    Guedon, Jean-Marc G; Wu, Shaogen; Zheng, Xuexing; Churchill, Caroline C; Glorioso, Joseph C; Liu, Ching-Hang; Liu, Shue; Vulchanova, Lucy; Bekker, Alex; Tao, Yuan-Xiang; Kinchington, Paul R; Goins, William F; Fairbanks, Carolyn A; Hao, Shuanglin

    2015-01-01

    The complexity of chronic pain and the challenges of pharmacotherapy highlight the importance of development of new approaches to pain management. Gene therapy approaches may be complementary to pharmacotherapy for several advantages. Gene therapy strategies may target specific chronic pain mechanisms in a tissue-specific manner. The present collection of articles features distinct gene therapy approaches targeting specific mechanisms identified as important in the specific pain conditions. Dr. Fairbanks group describes commonly used gene therapeutics (herpes simplex viral vector (HSV) and adeno-associated viral vector (AAV)), and addresses biodistribution and potential neurotoxicity in pre-clinical models of vector delivery. Dr. Tao group addresses that downregulation of a voltage-gated potassium channel (Kv1.2) contributes to the maintenance of neuropathic pain. Alleviation of chronic pain through restoring Kv1.2 expression in sensory neurons is presented in this review. Drs Goins and Kinchington group describes a strategy to use the replication defective HSV vector to deliver two different gene products (enkephalin and TNF soluble receptor) for the treatment of post-herpetic neuralgia. Dr. Hao group addresses the observation that the pro-inflammatory cytokines are an important shared mechanism underlying both neuropathic pain and the development of opioid analgesic tolerance and withdrawal. The use of gene therapy strategies to enhance expression of the anti-pro-inflammatory cytokines is summarized. Development of multiple gene therapy strategies may have the benefit of targeting specific pathologies associated with distinct chronic pain conditions (by Guest Editors, Drs. C. Fairbanks and S. Hao). PMID:25962909

  1. HSV Recombinant Vectors for Gene Therapy

    PubMed Central

    Manservigi, Roberto; Argnani, Rafaela; Marconi, Peggy

    2010-01-01

    The very deep knowledge acquired on the genetics and molecular biology of herpes simplex virus (HSV), has allowed the development of potential replication-competent and replication-defective vectors for several applications in human healthcare. These include delivery and expression of human genes to cells of the nervous systems, selective destruction of cancer cells, prophylaxis against infection with HSV or other infectious diseases, and targeted infection to specific tissues or organs. Replication-defective recombinant vectors are non-toxic gene transfer tools that preserve most of the neurotropic features of wild type HSV-1, particularly the ability to express genes after having established latent infections, and are thus proficient candidates for therapeutic gene transfer settings in neurons. A replication-defective HSV vector for the treatment of pain has recently entered in phase 1 clinical trial. Replication-competent (oncolytic) vectors are becoming a suitable and powerful tool to eradicate brain tumours due to their ability to replicate and spread only within the tumour mass, and have reached phase II/III clinical trials in some cases. The progress in understanding the host immune response induced by the vector is also improving the use of HSV as a vaccine vector against both HSV infection and other pathogens. This review briefly summarizes the obstacle encountered in the delivery of HSV vectors and examines the various strategies developed or proposed to overcome such challenges. PMID:20835362

  2. State of the art: gene therapy of haemophilia.

    PubMed

    Spencer, H T; Riley, B E; Doering, C B

    2016-07-01

    Clinical gene therapy has been practiced for more than a quarter century and the first products are finally gaining regulatory/marketing approval. As of 2016, there have been 11 haemophilia gene therapy clinical trials of which six are currently open. Each of the ongoing phase 1/2 trials is testing a variation of a liver-directed adeno-associated viral (AAV) vector encoding either factor VIII (FVIII) or factor IX (FIX) . As summarized herein, the clinical results to date have been mixed with some perceived success and a clear recognition of the immune response to AAV as an obstacle to therapeutic success. We also attempt to highlight promising late-stage preclinical activities for AAV-FVIII where, due to inherent challenges with manufacture, delivery and transgene product biosynthesis, more technological development has been necessary to achieve results comparable to what has been observed previously for AAV-FIX. Finally, we describe the development of a stem cell-based lentiviral vector gene therapy product that has the potential to provide lifelong production of FVIII and provide a functional 'cure' for haemophilia A. Integral to this program has been the incorporation of a blood cell-specific gene expression element driving the production of a bioengineered FVIII designed for optimal efficiency. As clearly outlined herein, haemophilia remains at the forefront of the rapidly advancing clinical gene therapy field where there exists a shared expectation that transformational advances are on the horizon. PMID:27405679

  3. Megakaryocyte- and megakaryocyte precursor–related gene therapies

    PubMed Central

    2016-01-01

    Hematopoietic stem cells (HSCs) can be safely collected from the body, genetically modified, and re-infused into a patient with the goal to express the transgene product for an individual’s lifetime. Hematologic defects that can be corrected with an allogeneic bone marrow transplant can theoretically also be treated with gene replacement therapy. Because some genetic disorders affect distinct cell lineages, researchers are utilizing HSC gene transfer techniques using lineage-specific endogenous gene promoters to confine transgene expression to individual cell types (eg, ITGA2B for inherited platelet defects). HSCs appear to be an ideal target for platelet gene therapy because they can differentiate into megakaryocytes which are capable of forming several thousand anucleate platelets that circulate within blood vessels to establish hemostasis by repairing vascular injury. Platelets play an essential role in other biological processes (immune response, angiogenesis) as well as diseased states (atherosclerosis, cancer, thrombosis). Thus, recent advances in genetic manipulation of megakaryocytes could lead to new and improved therapies for treating a variety of disorders. In summary, genetic manipulation of megakaryocytes has progressed to the point where clinically relevant strategies are being developed for human trials for genetic disorders affecting platelets. Nevertheless, challenges still need to be overcome to perfect this field; therefore, strategies to increase the safety and benefit of megakaryocyte gene therapy will be discussed. PMID:26787735

  4. Retinal Thickening and Photoreceptor Loss in HIV Eyes without Retinitis

    PubMed Central

    Arcinue, Cheryl A.; Bartsch, Dirk-Uwe; El-Emam, Sharif Y.; Ma, Feiyan; Doede, Aubrey; Sharpsten, Lucie; Gomez, Maria Laura; Freeman, William R.

    2015-01-01

    Purpose To determine the presence of structural changes in HIV retinae (i.e., photoreceptor density and retinal thickness in the macula) compared with age-matched HIV-negative controls. Methods Cohort of patients with known HIV under CART (combination Antiretroviral Therapy) treatment were examined with a flood-illuminated retinal AO camera to assess the cone photoreceptor mosaic and spectral-domain optical coherence tomography (SD-OCT) to assess retinal layers and retinal thickness. Results Twenty-four eyes of 12 patients (n = 6 HIV-positive and 6 HIV-negative) were imaged with the adaptive optics camera. In each of the regions of interest studied (nasal, temporal, superior, inferior), the HIV group had significantly less mean cone photoreceptor density compared with age-matched controls (difference range, 4,308–6,872 cones/mm2). A different subset of forty eyes of 20 patients (n = 10 HIV-positive and 10 HIV-negative) was included in the retinal thickness measurements and retinal layer segmentation with the SD-OCT. We observed significant thickening in HIV positive eyes in the total retinal thickness at the foveal center, and in each of the three horizontal B-scans (through the macular center, superior, and inferior to the fovea). We also noted that the inner retina (combined thickness from ILM through RNFL to GCL layer) was also significantly thickened in all the different locations scanned compared with HIV-negative controls. Conclusion Our present study shows that the cone photoreceptor density is significantly reduced in HIV retinae compared with age-matched controls. HIV retinae also have increased macular retinal thickness that may be caused by inner retinal edema secondary to retinovascular disease in HIV. The interaction of photoreceptors with the aging RPE, as well as possible low-grade ocular inflammation causing diffuse inner retinal edema, may be the key to the progressive vision changes in HIV-positive patients without overt retinitis. PMID:26244973

  5. Advancing Therapeutic Strategies for Inherited Retinal Degeneration: Recommendations From the Monaciano Symposium

    PubMed Central

    Thompson, Debra A.; Ali, Robin R.; Banin, Eyal; Branham, Kari E.; Flannery, John G.; Gamm, David M.; Hauswirth, William W.; Heckenlively, John R.; Iannaccone, Alessandro; Jayasundera, K. Thiran; Khan, Naheed W.; Molday, Robert S.; Pennesi, Mark E.; Reh, Thomas A.; Weleber, Richard G.; Zacks, David N.

    2015-01-01

    Although rare in the general population, retinal dystrophies occupy a central position in current efforts to develop innovative therapies for blinding diseases. This status derives, in part, from the unique biology, accessibility, and function of the retina, as well as from the synergy between molecular discoveries and transformative advances in functional assessment and retinal imaging. The combination of these factors has fueled remarkable progress in the field, while at the same time creating complex challenges for organizing collective efforts aimed at advancing translational research. The present position paper outlines recent progress in gene therapy and cell therapy for this group of disorders, and presents a set of recommendations for addressing the challenges remaining for the coming decade. It is hoped that the formulation of these recommendations will stimulate discussions among researchers, funding agencies, industry, and policy makers that will accelerate the development of safe and effective treatments for retinal dystrophies and related diseases. PMID:25667399

  6. Alphavirus vectors as tools in neuroscience and gene therapy.

    PubMed

    Lundstrom, Kenneth

    2016-05-01

    Alphavirus-based vectors have been engineered for in vitro and in vivo expression of heterelogous genes. The rapid and easy generation of replication-deficient recombinant particles and the broad range of host cell infection have made alphaviruses attractive vehicles for applications in neuroscience and gene therapy. Efficient delivery to primary neurons and hippocampal slices has allowed localization studies of gene expression and electrophysiological recordings of ion channels. Alphavirus vectors have also been applied for in vivo delivery to rodent brain. Due to the strong local transient expression provided by alphavirus vectors a number of immunization and gene therapy approaches have demonstrated both therapeutic and prophylactic efficacy in various animal models. PMID:26307195

  7. Neuroprotective effect of minocycline in a rat model of branch retinal vein occlusion.

    PubMed

    Sun, Chuan; Li, Xiao-Xin; He, Xiang-Jun; Zhang, Qi; Tao, Yong

    2013-08-01

    Branch retinal vein occlusion (BRVO) is the second most frequent retinal vascular disorder. Currently the first-line therapies for BRVO include anti-VEGF and dexamethasone implant treatment, however, with direct or indirect damage on retinal neurons, it has limited effect in improving patients visual acuity. Therefore, novel treatments with neuroprotective effect for BRVO retina were expected. Minocycline is a semisynthetic, broad spectrum tetracycline antibiotic with high penetration through the blood brain barrier. The neuroprotective effects of minocycline have been shown in various central nervous system (CNS) disease. Since both CNS and retina were composed of neurons and glials, it is reasonable to expect a neuroprotective effect by minocycline for BRVO retina. Therefore, the aim of the present study was to study whether minocycline has neuroprotective effect in branch retinal vein occlusion (BRVO) and the possible underlying molecular basis. We created BRVO in rats using laser photocoagulation. The animals were then randomly divided into 4 groups to evaluate the effect of minocycline: group A: minocycline 45 mg/kg intraperitoneal injection (i.p.), group B: minocycline 90 mg/kg i.p., group C: normal saline i.p., group D: sham injection. Fundus photography and fluorescein angiography (FA) were conducted. The changes in thickness of retinal layers were measured with optical coherence tomography (OCT) in vivo. We found that retinal edema occurred predominantly in the inner retinal layers. Intraperitoneal administration of minocycline significantly ameliorated retinal edema in the early stage of BRVO. We performed Full field Electroretinography (ffERG) to evaluate retinal function and found that the reduction of b wave amplitude decreased in the combined maximal response. The expressional levels of apoptosis related genes (Bax, Bcl-2) and inflammation related genes (IL-1 β, TNF α, MCP-1 and CCR2) were measured by real-time PCR, the results showed that

  8. Gene therapy for primary immunodeficiencies: current status and future prospects.

    PubMed

    Qasim, Waseem; Gennery, Andrew R

    2014-06-01

    Gene therapy using autologous haematopoietic stem cells offers a valuable treatment option for patients with primary immunodeficiencies who do not have access to an HLA-matched donor, although such treatments have not been without their problems. This review details gene therapy trials for X-linked and adenosine deaminase (ADA)-deficient severe combined immunodeficiency (SCID), Wiskott-Aldrich syndrome (WAS) and chronic granulomatous disease (CGD). X-linked SCID was chosen for gene therapy because of previous 'natural' genetic correction through a reversion event in a single lymphoid precursor, demonstrating limited thymopoiesis and restricted T-lymphocyte receptor repertoire, showing selective advantage of progenitors possessing the wild-type gene. In early studies, patients were treated with long terminal repeats-intact gamma-retroviral vectors, without additional chemotherapy. Early results demonstrated gene-transduced cells, sustained thymopoiesis, and a diverse T-lymphocyte repertoire with normal function. Serious adverse effects were subsequently reported in 5 of 20 patients, with T-lymphocyte leukaemia developing, secondary to the viral vector integrating adjacent to a known oncogene. New trials using self-inactivating gamma-retroviral vectors are progressing. Trials for ADA-SCID using gamma-retroviral vectors have been successful, with no similar serious adverse effects reported; trials using lentiviral vectors are in progress. Patients with WAS and CGD treated with early gamma-retroviral vectors have developed similar lymphoproliferative adverse effects to those seen in X-SCID--current trials are using new-generation vectors. Targeted gene insertion using homologous recombination of corrected gene sequences by cellular DNA repair pathways following targeted DNA breakage will improve efficacy and safety of gene therapy. A number of new techniques are discussed. PMID:24848753

  9. Glaucoma: genes, phenotypes, and new directions for therapy

    PubMed Central

    Fan, Bao Jian; Wiggs, Janey L.

    2010-01-01

    Glaucoma, a leading cause of blindness worldwide, is characterized by progressive optic nerve damage, usually associated with intraocular pressure. Although the clinical progression of the disease is well defined, the molecular events responsible for glaucoma are currently poorly understood and current therapeutic strategies are not curative. This review summarizes the human genetics and genomic approaches that have shed light on the complex inheritance of glaucoma genes and the potential for gene-based and cellular therapies that this research makes possible. PMID:20811162

  10. Dystrophin Gene Replacement and Gene Repair Therapy for Duchenne Muscular Dystrophy in 2016: An Interview.

    PubMed

    Duan, Dongsheng

    2016-03-01

    After years of relentless efforts, gene therapy has now begun to deliver its therapeutic promise in several diseases. A number of gene therapy products have received regulatory approval in Europe and Asia. Duchenne muscular dystrophy (DMD) is an X-linked inherited lethal muscle disease. It is caused by mutations in the dystrophin gene. Replacing and/or repairing the mutated dystrophin gene holds great promises to treated DMD at the genetic level. Last several years have evidenced significant developments in preclinical experimentations in murine and canine models of DMD. There has been a strong interest in moving these promising findings to clinical trials. In light of rapid progress in this field, the Parent Project Muscular Dystrophy (PPMD) recently interviewed me on the current status of DMD gene therapy and readiness for clinical trials. Here I summarized the interview with PPMD. PMID:27003751

  11. Repair of rhodopsin mRNA by spliceosome-mediated RNA trans-splicing: a new approach for autosomal dominant retinitis pigmentosa.

    PubMed

    Berger, Adeline; Lorain, Stéphanie; Joséphine, Charlène; Desrosiers, Melissa; Peccate, Cécile; Voit, Thomas; Garcia, Luis; Sahel, José-Alain; Bemelmans, Alexis-Pierre

    2015-05-01

    The promising clinical results obtained for ocular gene therapy in recent years have paved the way for gene supplementation to treat recessively inherited forms of retinal degeneration. The situation is more complex for dominant mutations, as the toxic mutant gene product must be removed. We used spliceosome-mediated RNA trans-splicing as a strategy for repairing the transcript of the rhodopsin gene, the gene most frequently mutated in autosomal dominant retinitis pigmentosa. We tested 17 different molecules targeting the pre-mRNA intron 1, by transient transfection of HEK-293T cells, with subsequent trans-splicing quantification at the transcript level. We found that the targeting of some parts of the intron promoted trans-splicing more efficiently than the targeting of other areas, and that trans-splicing rate could be increased by modifying the replacement sequence. We then developed cell lines stably expressing the rhodopsin gene, for the assessment of phenotypic criteria relevant to the pathogenesis of retinitis pigmentosa. Using this model, we showed that trans-splicing restored the correct localization of the protein to the plasma membrane. Finally, we tested our best candidate by AAV gene transfer in a mouse model of retinitis pigmentosa that expresses a mutant allele of the human rhodopsin gene, and demonstrated the feasibility of trans-splicing in vivo. This work paves the way for trans-splicing gene therapy to treat retinitis pigmentosa due to rhodopsin gene mutation and, more generally, for the treatment of genetic diseases with dominant transmission. PMID:25619725

  12. Repair of Rhodopsin mRNA by Spliceosome-Mediated RNA Trans-Splicing: A New Approach for Autosomal Dominant Retinitis Pigmentosa

    PubMed Central

    Berger, Adeline; Lorain, Stéphanie; Joséphine, Charlène; Desrosiers, Melissa; Peccate, Cécile; Voit, Thomas; Garcia, Luis; Sahel, José-Alain; Bemelmans, Alexis-Pierre

    2015-01-01

    The promising clinical results obtained for ocular gene therapy in recent years have paved the way for gene supplementation to treat recessively inherited forms of retinal degeneration. The situation is more complex for dominant mutations, as the toxic mutant gene product must be removed. We used spliceosome-mediated RNA trans-splicing as a strategy for repairing the transcript of the rhodopsin gene, the gene most frequently mutated in autosomal dominant retinitis pigmentosa. We tested 17 different molecules targeting the pre-mRNA intron 1, by transient transfection of HEK-293T cells, with subsequent trans-splicing quantification at the transcript level. We found that the targeting of some parts of the intron promoted trans-splicing more efficiently than the targeting of other areas, and that trans-splicing rate could be increased by modifying the replacement sequence. We then developed cell lines stably expressing the rhodopsin gene, for the assessment of phenotypic criteria relevant to the pathogenesis of retinitis pigmentosa. Using this model, we showed that trans-splicing restored the correct localization of the protein to the plasma membrane. Finally, we tested our best candidate by AAV gene transfer in a mouse model of retinitis pigmentosa that expresses a mutant allele of the human rhodopsin gene, and demonstrated the feasibility of trans-splicing in vivo. This work paves the way for trans-splicing gene therapy to treat retinitis pigmentosa due to rhodopsin gene mutation and, more generally, for the treatment of genetic diseases with dominant transmission. PMID:25619725

  13. Gene therapy ethics and haemophilia: an inevitable therapeutic future?

    PubMed

    Dimichele, D; Miller, F G; Fins, J J

    2003-03-01

    Haemophilia was recognized early on as an ideal candidate for a gene transfer approach to therapy. In the past decade, gene transfer experimentation in the haemophilias has indeed played an integral role in furthering the science in the global field of gene therapy. However, these expectations have placed haemophilia gene transfer researchers under pressure to succeed in a scientific domain in which successes are infrequent and progress is necessarily slow. These same expectations have also fueled the perception of gene therapy as the inevitable therapeutic goal for the youngest children with haemophilia. In this paper, we will discuss the ethical implications of this perception in light of anticipated benefits, acceptable risk, perceived consumer need and the unknown cost of this intervention. A framework for the future study and therapeutic implementation of gene transfer technology in this specific population is proposed. Public debate on this issue that includes the voices of the intended beneficiaries, especially the parents of the youngest children with haemophilia and the children themselves, is encouraged. PMID:12614364

  14. Genome-editing Technologies for Gene and Cell Therapy.

    PubMed

    Maeder, Morgan L; Gersbach, Charles A

    2016-03-01

    Gene therapy has historically been defined as the addition of new genes to human cells. However, the recent advent of genome-editing technologies has enabled a new paradigm in which the sequence of the human genome can be precisely manipulated to achieve a therapeutic effect. This includes the correction of mutations that cause disease, the addition of therapeutic genes to specific sites in the genome, and the removal of deleterious genes or genome sequences. This review presents the mechanisms of different genome-editing strategies and describes each of the common nuclease-based platforms, including zinc finger nucleases, transcription activator-like effector nucleases (TALENs), meganucleases, and the CRISPR/Cas9 system. We then summarize the progress made in applying genome editing to various areas of gene and cell therapy, including antiviral strategies, immunotherapies, and the treatment of monogenic hereditary disorders. The current challenges and future prospects for genome editing as a transformative technology for gene and cell therapy are also discussed. PMID:26755333

  15. Genome-editing Technologies for Gene and Cell Therapy

    PubMed Central

    Maeder, Morgan L; Gersbach, Charles A

    2016-01-01

    Gene therapy has historically been defined as the addition of new genes to human cells. However, the recent advent of genome-editing technologies has enabled a new paradigm in which the sequence of the human genome can be precisely manipulated to achieve a therapeutic effect. This includes the correction of mutations that cause disease, the addition of therapeutic genes to specific sites in the genome, and the removal of deleterious genes or genome sequences. This review presents the mechanisms of different genome-editing strategies and describes each of the common nuclease-based platforms, including zinc finger nucleases, transcription activator-like effector nucleases (TALENs), meganucleases, and the CRISPR/Cas9 system. We then summarize the progress made in applying genome editing to various areas of gene and cell therapy, including antiviral strategies, immunotherapies, and the treatment of monogenic hereditary disorders. The current challenges and future prospects for genome editing as a transformative technology for gene and cell therapy are also discussed. PMID:26755333

  16. Gene therapy for lung inflammatory diseases: not so far away?

    PubMed Central

    Sallenave, J. M.; Porteous, D. J.; Haslett, C.

    1997-01-01

    The lung is a readily accessible target organ for gene therapy. To date, therapeutic gene delivery has largely focused on introducing functional, corrective genes in lung diseases arising from single gene defects such as cystic fibrosis. More recently interest has centred on gene therapy as a potential therapeutic tool in modulating complex pathological processes such as pulmonary inflammation. Genetic modification of critical components of the inflammatory process may be beneficial-for example, overexpressing anti-elastase genes may circumvent elastase mediated lung damage in emphysema. With the development of improved viral and liposome vectors and the evolution of effective adjuvant immunosuppression to obviate host immune responses-- for example, using selective cytokines and blockers of T cell surface activation--the potential exists to target therapeutic doses of transgene to deficient or dysregulated cells. Furthermore, increased understanding of tissue-specific promoter regions and of mechanisms controlling regulation of gene expression offer the potential for close control of therapeutic gene expression within the lung. Continuing refinements in these technologies will provide new therapeutic strategies in inflammatory lung disease. 


 PMID:9337837

  17. Gene therapy for lung inflammatory diseases: not so far away?

    PubMed

    Sallenave, J M; Porteous, D J; Haslett, C

    1997-08-01

    The lung is a readily accessible target organ for gene therapy. To date, therapeutic gene delivery has largely focused on introducing functional, corrective genes in lung diseases arising from single gene defects such as cystic fibrosis. More recently interest has centred on gene therapy as a potential therapeutic tool in modulating complex pathological processes such as pulmonary inflammation. Genetic modification of critical components of the inflammatory process may be beneficial-for example, overexpressing anti-elastase genes may circumvent elastase mediated lung damage in emphysema. With the development of improved viral and liposome vectors and the evolution of effective adjuvant immunosuppression to obviate host immune responses--for example, using selective cytokines and blockers of T cell surface activation--the potential exists to target therapeutic doses of transgene to deficient or dysregulated cells. Furthermore, increased understanding of tissue-specific promoter regions and of mechanisms controlling regulation of gene expression offer the potential for close control of therapeutic gene expression within the lung. Continuing refinements in these technologies will provide new therapeutic strategies in inflammatory lung disease. PMID:9337837

  18. Characterization and mapping of the human rhodopsin kinase gene and screening of the gene for mutations in patients with retinitis pigmentosa

    SciTech Connect

    Khani, S.C.; Lin, D.; Magovcevic, I.

    1994-09-01

    Rhodopsin kinase (RK) is a cytosolic enzyme in rod photoreceptors that initiates the deactivation of the phototransductions cascade by phosphorylating photoactivated rhodopsin. Although the cDNA sequence of bovine RK has been determined previously, no human cDNA or genomic sequence has thus far been available for genetic studies. In order to investigate the possible role of this candidate gene in retinitis pigmentosa (RP) and allied diseases, we have isolated and characterized human cDNA and genomic clones derived from the RK locus. The coding sequence of the human gene is 1692 nucleotides in length and is split into seven exons. The human and the bovine sequence show 84% identity at the nucleotide level and 92% identity at the amino acid level. Thus far, the intronic sequences flanking each exon except for one have been determined. We have also mapped the human RK gene to chromosome 13q34 using fluorescence in situ hybridization. To our knowledge, no RP gene has as yet been linked to this region. However, since the substrate for RK (rhodopsin) and other members of the phototransduction cascade have been implicated in the pathogenesis of RP, it is conceivable that defects in RK can also cause some forms of this disease. We are evaluating this possibility by screening DNA from 173 patients with autosomal recessive RP and 190 patients with autosomal dominant RP. So far, we have found 11 patients with variant bands. In one patient with autosomal dominant RP we discovered the missense change Ser536Leu. Cosegregation studies and further sequencing of the variant bands are currently underway.

  19. Whole-exome sequencing reveals a novel frameshift mutation in the FAM161A gene causing autosomal recessive retinitis pigmentosa in the Indian population.

    PubMed

    Zhou, Yu; Saikia, Bibhuti B; Jiang, Zhilin; Zhu, Xiong; Liu, Yuqing; Huang, Lulin; Kim, Ramasamy; Yang, Yin; Qu, Chao; Hao, Fang; Gong, Bo; Tai, Zhengfu; Niu, Lihong; Yang, Zhenglin; Sundaresan, Periasamy; Zhu, Xianjun

    2015-10-01

    Retinitis pigmentosa (RP) is a heterogenous group of inherited retinal degenerations caused by mutations in at least 50 genes. To identify genetic mutations underlying autosomal recessive RP (arRP), we performed whole-exome sequencing study on two consanguineous marriage Indian families (RP-252 and RP-182) and 100 sporadic RP patients. Here we reported novel mutation in FAM161A in RP-252 and RP-182 with two patients affected with RP in each family. The FAM161A gene was identified as the causative gene for RP28, an autosomal recessive form of RP. By whole-exome sequencing we identified several homozygous genomic regions, one of which included the recently identified FAM161A gene mutated in RP28-linked arRP. Sequencing analysis revealed the presence of a novel homozygous frameshift mutation p.R592FsX2 in both patients of family RP-252 and family RP-182. In 100 sporadic Indian RP patients, this novel homozygous frameshift mutation p.R592FsX2 was identified in one sporadic patient ARRP-S-I-46 by whole-exome sequencing and validated by Sanger sequencing. Meanwhile, this homozygous frameshift mutation was absent in 1000 ethnicity-matched control samples screened by direct Sanger sequencing. In conclusion, we identified a novel homozygous frameshift mutations of RP28-linked RP gene FAM161A in Indian population. PMID:26246154

  20. Functional imaging of inherited retinal disease with a commercial optical coherence tomography device

    NASA Astrophysics Data System (ADS)

    Theelen, T.; Hoyng, C. B.; Klevering, B. J.; Cense, B.

    2011-06-01

    Retinal dystrophies (RD) are blinding diseases affecting visual acuity mostly at young age. Intrinsic optical signals (IOS) on optical coherence tomography (OCT) may give topographical information on injure of retinal function in these patients. We demonstrate light response of the healthy and diseased human retina by IOS on a commercially available spectral-domain OCT. Significant IOS could be measured in the healthy retina and in unchanged retinal sectors of the RD patients. Main responses were located in the outer retina (photoreceptors) and the nerve fiber layer. In affected areas of RD eyes IOS were significantly reduced or even absent. Functional OCT imaging was able to give information about retinal function in RD patients on a micrometer scale. These results could be of value for refined disease analysis and control of upcoming gene therapy studies.

  1. Quantitative analysis of retinal OCT.

    PubMed

    Sonka, Milan; Abràmoff, Michael D

    2016-10-01

    Clinical acceptance of 3-D OCT retinal imaging brought rapid development of quantitative 3-D analysis of retinal layers, vasculature, retinal lesions as well as facilitated new research in retinal diseases. One of the cornerstones of many such analyses is segmentation and thickness quantification of retinal layers and the choroid, with an inherently 3-D simultaneous multi-layer LOGISMOS (Layered Optimal Graph Image Segmentation for Multiple Objects and Surfaces) segmentation approach being extremely well suited for the task. Once retinal layers are segmented, regional thickness, brightness, or texture-based indices of individual layers can be easily determined and thus contribute to our understanding of retinal or optic nerve head (ONH) disease processes and can be employed for determination of disease status, treatment responses, visual function, etc. Out of many applications, examples provided in this paper focus on image-guided therapy and outcome prediction in age-related macular degeneration and on assessing visual function from retinal layer structure in glaucoma. PMID:27503080

  2. Novel molecular approaches to cystic fibrosis gene therapy

    PubMed Central

    Lee, Tim W. R.; Matthews, David A.; Blair, G. Eric

    2005-01-01

    Gene therapy holds promise for the treatment of a range of inherited diseases, such as cystic fibrosis. However, efficient delivery and expression of the therapeutic transgene at levels sufficient to result in phenotypic correction of cystic fibrosis pulmonary disease has proved elusive. There are many reasons for this lack of progress, both macroscopically in terms of airway defence mechanisms and at the molecular level with regard to effective cDNA delivery. This review of approaches to cystic fibrosis gene therapy covers these areas in detail and highlights recent progress in the field. For gene therapy to be effective in patients with cystic fibrosis, the cDNA encoding the cystic fibrosis transmembrane conductance regulator protein must be delivered effectively to the nucleus of the epithelial cells lining the bronchial tree within the lungs. Expression of the transgene must be maintained at adequate levels for the lifetime of the patient, either by repeat dosage of the vector or by targeting airway stem cells. Clinical trials of gene therapy for cystic fibrosis have demonstrated proof of principle, but gene expression has been limited to 30 days at best. Results suggest that viral vectors such as adenovirus and adeno-associated virus are unsuited to repeat dosing, as the immune response reduces the effectiveness of each subsequent dose. Nonviral approaches, such as cationic liposomes, appear more suited to repeat dosing, but have been less effective. Current work regarding non-viral gene delivery is now focused on understanding the mechanisms involved in cell entry, endosomal escape and nuclear import of the transgene. There is now increasing evidence to suggest that additional ligands that facilitate endosomal escape or contain a nuclear localization signal may enhance liposome-mediated gene delivery. Much progress in this area has been informed by advances in our understanding of the mechanisms by which viruses deliver their genomes to the nuclei of host

  3. Lentiviral Hematopoietic Stem Cell Gene Therapy in Inherited Metabolic Disorders

    PubMed Central

    2014-01-01

    Abstract After more than 20 years of development, lentiviral hematopoietic stem cell gene therapy has entered the stage of initial clinical implementation for immune deficiencies and storage disorders. This brief review summarizes the development and applications, focusing on the lysosomal enzyme deficiencies, especially Pompe disease. PMID:25184354

  4. Gene Therapy for the Treatment of Primary Immune Deficiencies.

    PubMed

    Kuo, Caroline Y; Kohn, Donald B

    2016-05-01

    The use of gene therapy in the treatment of primary immune deficiencies (PID) has advanced significantly in the last decade. Clinical trials for X-linked severe combined immunodeficiency, adenosine deaminase deficiency (ADA), chronic granulomatous disease, and Wiskott-Aldrich syndrome have demonstrated that gene transfer into hematopoietic stem cells and autologous transplant can result in clinical improvement and is curative for many patients. Unfortunately, early clinical trials were complicated by vector-related insertional mutagenic events for several diseases with the exception of ADA-deficiency SCID. These results prompted the current wave of clinical trials for primary immunodeficiency using alternative retro- or lenti-viral vector constructs that are self-inactivating, and they have shown clinical efficacy without leukemic events thus far. The field of gene therapy continues to progress, with improvements in viral vector profiles, stem cell culturing techniques, and site-specific genome editing platforms. The future of gene therapy is promising, and we are quickly moving towards a time when it will be a standard cellular therapy for many forms of PID. PMID:27056559

  5. Genomic DNA nanoparticles rescue rhodopsin-associated retinitis pigmentosa phenotype.

    PubMed

    Han, Zongchao; Banworth, Marcellus J; Makkia, Rasha; Conley, Shannon M; Al-Ubaidi, Muayyad R; Cooper, Mark J; Naash, Muna I

    2015-06-01

    Mutations in the rhodopsin gene cause retinal degeneration and clinical phenotypes including retinitis pigmentosa (RP) and congenital stationary night blindness. Effective gene therapies have been difficult to develop, however, because generating precise levels of rhodopsin expression is critical; overexpression causes toxicity, and underexpression would result in incomplete rescue. Current gene delivery strategies routinely use cDNA-based vectors for gene targeting; however, inclusion of noncoding components of genomic DNA (gDNA) such as introns may help promote more endogenous regulation of gene expression. Here we test the hypothesis that inclusion of genomic sequences from the rhodopsin gene can improve the efficacy of rhodopsin gene therapy in the rhodopsin knockout (RKO) mouse model of RP. We utilize our compacted DNA nanoparticles (NPs), which have the ability to transfer larger and more complex genetic constructs, to deliver murine rhodopsin cDNA or gDNA. We show functional and structural improvements in RKO eyes for up to 8 months after NP-mediated gDNA but not cDNA delivery. Importantly, in addition to improvements in rod function, we observe significant preservation of cone function at time points when cones in the RKO model are degenerated. These results suggest that inclusion of native expression elements, such as introns, can significantly enhance gene expression and therapeutic efficacy and may become an essential option in the array of available gene delivery tools. PMID:25713057

  6. Molecular genetics of retinitis pigmentosa.

    PubMed Central

    Farber, D. B.; Heckenlively, J. R.; Sparkes, R. S.; Bateman, J. B.

    1991-01-01

    Retinitis pigmentosa is a model for the study of genetic diseases. Its genetic heterogeneity is reflected in the different forms of inheritance (autosomal dominant, autosomal recessive, or X-linked) and, in a few families, in the presence of mutations in the visual pigment rhodopsin. Clinical and molecular genetic studies of these disorders are discussed. Animal models of retinal degeneration have been investigated for many years with the hope of gaining insight into the cause of photoreceptor cell death. Recently, the genes responsible for two of these animal disorders, the rds and rd mouse genes, have been isolated and characterized. The retinal degeneration of the rd mouse is presented in detail. The possible involvement of human analogues of these mouse genes in human retinal diseases is being investigated. Images PMID:1771877

  7. Targeted expression of suicide gene by tissue-specific promoter and microRNA regulation for cancer gene therapy.

    PubMed

    Danda, Ravikanth; Krishnan, Gopinath; Ganapathy, Kalaivani; Krishnan, Uma Maheswari; Vikas, Khetan; Elchuri, Sailaja; Chatterjee, Nivedita; Krishnakumar, Subramanian

    2013-01-01

    In order to realise the full potential of cancer suicide gene therapy that allows the precise expression of suicide gene in cancer cells, we used a tissue specific Epithelial cell adhesion molecule (EpCAM) promoter (EGP-2) that directs transgene Herpes simplex virus-thymidine kinase (HSV-TK) expression preferentially in EpCAM over expressing cancer cells. EpCAM levels are considerably higher in retinoblastoma (RB), a childhood eye cancer with limited expression in normal cells. Use of miRNA regulation, adjacent to the use of the tissue-specific promoter, would provide the second layer of control to the transgene expression only in the tumor cells while sparing the normal cells. To test this hypothesis we cloned let-7b miRNA targets in the 3'UTR region of HSV-TK suicide gene driven by EpCAM promoter because let-7 family miRNAs, including let-7b, were found to be down regulated in the RB tumors and cell lines. We used EpCAM over expressing and let-7 down regulated RB cell lines Y79, WERI-Rb1 (EpCAM (+ve)/let-7b(down-regulated)), EpCAM down regulated, let-7 over expressing normal retinal Müller glial cell line MIO-M1(EpCAM (-ve)/let-7b(up-regulated)), and EpCAM up regulated, let-7b up-regulated normal thyroid cell line N-Thy-Ori-3.1(EpCAM (+ve)/let-7b(up-regulated)) in the study. The cell proliferation was measured by MTT assay, apoptosis was measured by probing cleaved Caspase3, EpCAM and TK expression were quantified by Western blot. Our results showed that the EGP2-promoter HSV-TK (EGP2-TK) construct with 2 or 4 copies of let-7b miRNA targets expressed TK gene only in Y79, WERI-Rb-1, while the TK gene did not express in MIO-M1. In summary, we have developed a tissue-specific, miRNA-regulated dual control vector, which selectively expresses the suicide gene in EpCAM over expressing cells. PMID:24391761

  8. Conditional knockout of retinal determination genes in differentiating cells in Drosophila.

    PubMed

    Jin, Meng; Eblimit, Aiden; Pulikkathara, Merlyn; Corr, Stuart; Chen, Rui; Mardon, Graeme

    2016-08-01

    Conditional gene knockout in postmitotic cells is a valuable technique which allows the study of gene function with spatiotemporal control. Surprisingly, in contrast to its long-term and extensive use in mouse studies, this technology is lacking in Drosophila. Here, we use a novel method for generating complete loss of eyes absent (eya) or sine oculis (so) function in postmitotic cells posterior to the morphogenetic furrow (MF). Specifically, genomic rescue constructs with flippase recognition target (FRT) sequences flanking essential exons are used to generate conditional null alleles. By removing gene function in differentiating cells, we show that eya and so are dispensable for larval photoreceptor differentiation, but are required for differentiation during pupal development. Both eya and so are necessary for photoreceptor survival and the apoptosis caused by loss of eya or so function is likely a secondary consequence of inappropriate differentiation. We also confirm their requirement for cone cell development and reveal a novel role in interommatidial bristle (IOB) formation. In addition, so is required for normal eye disc morphology. This is the first report of a knockout method to study eya and so function in postmitotic cells. This technology will open the door to a large array of new functional studies in virtually any tissue and at any stage of development or in adults. PMID:27257739

  9. Changes in gene expression associated with retinal degeneration in the rd3 mouse

    PubMed Central

    Cheng, Christiana L.

    2013-01-01

    Purpose To identify and characterize changes in gene expression associated with photoreceptor degeneration in the rd3 mouse model of Leber congenital amaurosis (LCA) type 12. Methods Global genome expression profiling using microarray technology was performed on total RNA extracts from rd3 and wild-type control mouse retinas at postnatal day 21. Quantitative PCR analysis of selected transcripts was performed to validate the microarray results. Results Functional annotation of differentially regulated genes in the rd3 mouse defined key canonical pathways, including phototransduction, glycerophospholipid metabolism, tumor necrosis factor receptor 1 signaling, and endothelin signaling. Overall, 1,140 of approximately 55,800 transcripts were differentially represented. In particular, a large percentage of the upregulated transcripts encode proteins involved in the immune response; whereas the downregulated transcripts encode proteins involved in phototransduction and lipid metabolism. Conclusions This analysis has elucidated several candidate genes and pathways, thus providing insight into the pathogenic mechanisms underlying the photoreceptor degeneration in the rd3 mouse retina and indicating directions for future studies. PMID:23687432

  10. Retinal Prosthesis

    PubMed Central

    Weiland, James D.; Humayun, Mark S.

    2015-01-01

    Retinal prosthesis have been translated from the laboratory to the clinical over the past two decades. Currently, two devices have regulatory approval for the treatment of retinitis pigmentosa. These devices provide partial sight restoration and patients use this improved vision in their everyday lives. Improved mobility and object detection are some of the more notable findings from the clinical trials. However, significant vision restoration will require both better technology and improved understanding of the interaction between electrical stimulation and the retina. This paper reviews the recent clinical trials, highlights technology breakthroughs that will contribute to next generation of retinal prostheses. PMID:24710817

  11. Foveomacular retinitis.

    PubMed Central

    Kuming, B S

    1986-01-01

    A group of patients is described who developed the clinical features of foveomacular retinitis. No causative factors were isolated, and all patients strongly denied any type of sun gazing. It is possible that there is a group of patients who have the features of foveomacular retinitis but have not had any direct exposure to the sun. These patients would then constitute a primary type of foveomacular retinitis, as opposed to a secondary type which has a known cause and is synonymous with solar retinopathy. Images PMID:3790482

  12. Gene therapy for aromatic L-amino acid decarboxylase deficiency.

    PubMed

    Hwu, Wuh-Liang; Muramatsu, Shin-ichi; Tseng, Sheng-Hong; Tzen, Kai-Yuan; Lee, Ni-Chung; Chien, Yin-Hsiu; Snyder, Richard O; Byrne, Barry J; Tai, Chun-Hwei; Wu, Ruey-Meei

    2012-05-16

    Aromatic L-amino acid decarboxylase (AADC) is required for the synthesis of the neurotransmitters dopamine and serotonin. Children with defects in the AADC gene show compromised development, particularly in motor function. Drug therapy has only marginal effects on some of the symptoms and does not change early childhood mortality. Here, we performed adeno-associated viral vector-mediated gene transfer of the human AADC gene bilaterally into the putamen of four patients 4 to 6 years of age. All of the patients showed improvements in motor performance: One patient was able to stand 16 months after gene transfer, and the other three patients achieved supported sitting 6 to 15 months after gene transfer. Choreic dyskinesia was observed in all patients, but this resolved after several months. Positron emission tomography revealed increased uptake by the putamen of 6-[(18)F]fluorodopa, a tracer for AADC. Cerebrospinal fluid analysis showed increased dopamine and serotonin levels after