title: AAV-based shRNA silencing of NF-κB ameliorates muscle pathologies in mdx mice.
abstract: Chronic inflammation, promoted by an upregulated NF-kappa B (NF-κB) pathway, has a key role in Duchenne muscular dystrophy (DMD) patients' pathogenesis. Blocking the NF-κB pathway has been shown to be a viable approach to diminish chronic inflammation and necrosis in the dystrophin-defective mdx mouse, a murine DMD model. In this study, we used the recombinant adeno-associated virus serotype 9 (AAV9) carrying an short hairpin RNA (shRNA) specifically targeting the messenger RNA of NF-κB/p65 (p65-shRNA), the major subunit of NF-κB associated with chronic inflammation in mdx mice. We examined whether i.m. AAV9-mediated delivery of p65-shRNA could decrease NF-κB activation, allowing for amelioration of muscle pathologies in 1- and 4-month-old mdx mice. At 1 month after treatment, NF-κB/p65 levels were significantly decreased by AAV gene transfer of p65-shRNA in the two ages of treatment groups, with necrosis significantly decreased compared with controls. Quantitative analysis revealed that central nucleation (CN) of the myofibers of p65-shRNA-treated 1-month-old mdx muscles was reduced from 67 to 34%, but the level of CN was not significantly decreased in treated 4-month-old mdx mice. Moreover, delivery of the p65-shRNA enhanced the capacity of myofiber regeneration in old mdx mice treated at 4 months of age when the dystrophic myofibers were most exhausted; however, such p65 silencing diminished the myofiber regeneration in young mdx mice treated at 1 month of age. Taken together, these findings demonstrate that the AAV-mediated delivery of p65-shRNA has the capacity to ameliorate muscle pathologies in mdx mice by selectively reducing NF-κB/p65 activity.
authors.affiliation: Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA 15219, USA.
authors.forename: Q
authors.initials: Q
authors.lastname: Yang
authors.forename: Y
authors.initials: Y
authors.lastname: Tang
authors.forename: K
authors.initials: K
authors.lastname: Imbrogno
authors.forename: A
authors.initials: A
authors.lastname: Lu
authors.forename: J D
authors.initials: JD
authors.lastname: Proto
authors.forename: A
authors.initials: A
authors.lastname: Chen
authors.forename: F
authors.initials: F
authors.lastname: Guo
authors.forename: F H
authors.initials: FH
authors.lastname: Fu
authors.forename: J
authors.initials: J
authors.lastname: Huard
authors.forename: B
authors.initials: B
authors.lastname: Wang
mesh_terms: D000818:Animals; D000229:Dependovirus / Q000235:genetics; D008297:Male; D051379:Mice; D018101:Mice, Inbred mdx; D018482:Muscle, Skeletal / Q000473:pathology*; D020388:Muscular Dystrophy, Duchenne / Q000235:genetics* / Q000473:pathology; D016328:NF-kappa B / Q000235:genetics* / Q000378:metabolism; D034741:RNA, Small Interfering; D012038:Regeneration / Q000235:genetics
chemical_list: D016328:NF-kappa B; D034741:RNA, Small Interfering