title: Lentivirus-mediated expression of cDNA and shRNA slows degeneration in retinitis pigmentosa.
abstract: Mutations in Pde6b lead to high levels of signaling molecules cyclic guanosine monophosphate (cGMP) and Ca(2+), which ultimately result in photoreceptor cell death in certain forms of retinitis pigmentosa (RP). The level of cGMP, which is controlled by opposing activities of guanylate cyclase (GUCY) and photoreceptor phosphodiesterase-6 (PDE6), regulates the opening of cyclic nucleotide-gated ion channels [CNG] and thereby controls Ca(2+) influx into the outer segments. Using a lentiviral gene therapy approach, we have previously shown that degeneration can be temporarily slowed either by introducing wild-type PDE6β or knocking down expression of GUCY2E and CNGA1 in photoreceptors of Pde6b(H620Q), a mouse model for RP. Rescue was transient with either approach. Therefore, we tested a novel combination therapy using bipartite lentiviral vectors designed to both introduce wild-type PDE6β expression and knockdown GUCY2E or CNGA1. Immunoblot analysis shows simultaneous increases in PDE6β and decreases in GUCY2E or CNGA1 in retinas transduced by the vectors, indicating successful transduction. In Pde6b(H620Q) mutants, we observe rescue of photoreceptor function and an increase in photoreceptor rows as compared with untreated controls. However, no evidence of prolonged rescue beyond the limit of the previously tested single therapy was observed.
authors: Bernard & Shirlee Brown Glaucoma Laboratory, Department of Pathology & Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
authors: Joaquin
authors: J
authors: Tosi
authors: Javier
authors: J
authors: Sancho-Pelluz
authors: Richard J
authors: RJ
authors: Davis
authors: Chun Wei
authors: CW
authors: Hsu
authors: Kyle V
authors: KV
authors: Wolpert
authors: Jesse D
authors: JD
authors: Sengillo
authors: Chyuan-Sheng
authors: CS
authors: Lin
authors: Stephen H
authors: SH
authors: Tsang
mesh_terms: D000818:Animals; D054707:Cyclic Nucleotide Phosphodiesterases, Type 6 / Q000235:genetics; D018076:DNA, Complementary / Q000627:therapeutic use*; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000235:genetics / Q000627:therapeutic use; D016086:Lentivirus / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D020419:Photoreceptor Cells, Vertebrate / Q000502:physiology; D034741:RNA, Small Interfering / Q000627:therapeutic use*; D012160:Retina / Q000378:metabolism / Q000821:virology; D012174:Retinitis Pigmentosa / Q000235:genetics / Q000628:therapy*; D014161:Transduction, Genetic / Q000379:methods
chemical_list: D018076:DNA, Complementary; D034741:RNA, Small Interfering; D054707:Cyclic Nucleotide Phosphodiesterases, Type 6; C517438:Pde6b protein, mouse