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Xin C, Chu X, Wei W, Kuang B, Wang Y, Tang Y, Chen J, You H, Li C, Wang B. Combined gene therapy via VEGF and mini-dystrophin synergistically improves pathologies in temporalis muscle of dystrophin/utrophin double knockout mice. Hum Mol Genet 2021; 30:1349-1359. [PMID: 33987645 DOI: 10.1093/hmg/ddab120] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 04/15/2021] [Accepted: 04/19/2021] [Indexed: 12/16/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a severe X-linked inherited muscular disorder characterized by the loss of dystrophin. We have previously shown that monogene therapy using the mini-dystrophin gene improves muscle function in DMD. However, chronic inflammation plays an important role in progressive muscle degeneration in DMD as well. Vascular endothelial growth factor (VEGF) has been used to enhance muscle vasculature, reduce local inflammation and improve DMD muscle function. Temporalis muscles are the key skeletal muscles for mastication and loss of their function negatively affects DMD patient quality of life by reducing nutritional intake, but little is known about the pathology and treatment of the temporalis muscle in DMD. In this work, we tested the hypothesis that the combined delivery of the human mini-dystrophin and human VEGF genes to the temporalis muscles using separate recombinant adeno-associated viral (rAAV) vectors will synergistically improve muscle function and pathology in adult male dystrophin/utrophin double-knockout (mdx/utrn+/-) mice. The experimental mice were divided into four groups including: dystrophin + VEGF combined, dystrophin only, VEGF only and PBS control. After 2 months, gene expression and histological analysis of the temporalis muscles showed a synergistic improvement in temporalis muscle pathology and function coincident with increased restoration of dystrophin-associated protein complexes and nNOS in the dystrophin + VEGF combined group. We also observed significantly reduced inflammatory cell infiltration, central nucleation, and fibrosis in the dystrophin + VEGF combined group. We have demonstrated the efficacy of combined rAAV-mediated dystrophin and VEGF treatment of temporalis muscles in a DMD mouse model.
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Affiliation(s)
- Can Xin
- Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA.,Department of Neurosurgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, 430071, China
| | - Xiangyu Chu
- Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA.,Department of Orthopedics, Tongji Hospital, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Wenzhong Wei
- Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA.,Department of Immunology, University of Pittsburgh, PA, 15213, USA
| | - Biao Kuang
- Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA.,Department of Orthopedics, Xiangya Hospital, Zhongnan University, Changsha, Hunan, 410008, China
| | - Yiqing Wang
- Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA
| | - Ying Tang
- Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA.,Center for Pulmonary Vascular Biology and Medicine, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Jincao Chen
- Department of Neurosurgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei, 430071, China
| | - Hongbo You
- Department of Orthopedics, Tongji Hospital, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Chengwen Li
- Gene Therapy Center, Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Bing Wang
- Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA
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Mu W, Xu B, Ma H, Ji B, Zhang Z, Li J, Amat A, Cao L. Halofuginone attenuates articular cartilage degeneration by inhibition of elevated TGF‑β1 signaling in articular cartilage in a rodent osteoarthritis model. Mol Med Rep 2017; 16:7679-7684. [PMID: 28944864 DOI: 10.3892/mmr.2017.7549] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 08/14/2017] [Indexed: 11/05/2022] Open
Abstract
Osteoarthritis (OA) is the most common degenerative condition of the weight‑bearing joints worldwide without effective medical therapy. In order to investigate whether administration of halofuginone (HF) may attenuate OA, the present study allocated 3‑month‑old male mice into Sham group, vehicle‑treated anterior cruciate ligament transection (ACLT) group and HF‑treated ACLT group. The present study determined that HF treatment reduced the expression of matrix metallopeptidase‑13 and collagen X in articular cartilage. Additionally, it lowered the Osteoarthritis Research Society International‑Modified Mankin score and prevented the loss of articular cartilage from Safranin O and Fast Green staining. HF reduced the progression of osteoarthritis by downregulating abnormally elevated TGF‑β1 activity in articular cartilage. Administration of HF may be a potential preventive therapy for OA.
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Affiliation(s)
- Wenbo Mu
- Department of Orthopaedics, First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830054, P.R. China
| | - Boyong Xu
- Department of Orthopaedics, First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830054, P.R. China
| | - Hairong Ma
- Department of Orthopaedics, First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830054, P.R. China
| | - Baochao Ji
- Department of Orthopaedics, First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830054, P.R. China
| | - Zhendong Zhang
- Department of Orthopaedics, First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830054, P.R. China
| | - Jiao Li
- Department of Orthopaedics, First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830054, P.R. China
| | - Abdusami Amat
- Department of Orthopaedics, First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830054, P.R. China
| | - Li Cao
- Department of Orthopaedics, First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830054, P.R. China
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Yin X, Tang Y, Li J, Dzuricky AT, Pu C, Fu F, Wang B. Genetic ablation of P65 subunit of NF‐κB in
mdx
mice to improve muscle physiological function. Muscle Nerve 2017; 56:759-767. [DOI: 10.1002/mus.25517] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 12/07/2016] [Accepted: 12/09/2016] [Indexed: 01/05/2023]
Affiliation(s)
- Xi Yin
- Department of Orthopaedic SurgeryUniversity of PittsburghSuite 216, Bridgeside Point II, 450 Technology Drive, Pittsburgh Pennsylvania 15219 USA
- Department of Geriatric NeurologyChinese PLA General HospitalBeijing China
| | - Ying Tang
- Department of Orthopaedic SurgeryUniversity of PittsburghSuite 216, Bridgeside Point II, 450 Technology Drive, Pittsburgh Pennsylvania 15219 USA
| | - Jian Li
- Department of Orthopaedic SurgeryUniversity of PittsburghSuite 216, Bridgeside Point II, 450 Technology Drive, Pittsburgh Pennsylvania 15219 USA
- Beijing Friendship HospitalCapital Medical UniversityBeijing China
| | - Anna T. Dzuricky
- Department of Orthopaedic SurgeryUniversity of PittsburghSuite 216, Bridgeside Point II, 450 Technology Drive, Pittsburgh Pennsylvania 15219 USA
| | - Chuanqiang Pu
- Department of Geriatric NeurologyChinese PLA General HospitalBeijing China
| | - Freddie Fu
- Department of Orthopaedic SurgeryUniversity of PittsburghSuite 216, Bridgeside Point II, 450 Technology Drive, Pittsburgh Pennsylvania 15219 USA
| | - Bing Wang
- Department of Orthopaedic SurgeryUniversity of PittsburghSuite 216, Bridgeside Point II, 450 Technology Drive, Pittsburgh Pennsylvania 15219 USA
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Cui Z, Crane J, Xie H, Jin X, Zhen G, Li C, Xie L, Wang L, Bian Q, Qiu T, Wan M, Xie M, Ding S, Yu B, Cao X. Halofuginone attenuates osteoarthritis by inhibition of TGF-β activity and H-type vessel formation in subchondral bone. Ann Rheum Dis 2015; 75:1714-21. [PMID: 26470720 PMCID: PMC5013081 DOI: 10.1136/annrheumdis-2015-207923] [Citation(s) in RCA: 167] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 09/20/2015] [Indexed: 12/28/2022]
Abstract
Objectives Examine whether osteoarthritis (OA) progression can be delayed by halofuginone in anterior cruciate ligament transection (ACLT) rodent models. Methods 3-month-old male C57BL/6J (wild type; WT) mice and Lewis rats were randomised to sham-operated, ACLT-operated, treated with vehicle, or ACLT-operated, treated with halofuginone. Articular cartilage degeneration was graded using the Osteoarthritis Research Society International (OARSI)-modified Mankin criteria. Immunostaining, flow cytometry, RT-PCR and western blot analyses were conducted to detect relative protein and RNA expression. Bone micro CT (μCT) and CT-based microangiography were quantitated to detect alterations of microarchitecture and vasculature in tibial subchondral bone. Results Halofuginone attenuated articular cartilage degeneration and subchondral bone deterioration, resulting in substantially lower OARSI scores. Specifically, we found that proteoglycan loss and calcification of articular cartilage were significantly decreased in halofuginone-treated ACLT rodents compared with vehicle-treated ACLT controls. Halofuginone reduced collagen X (Col X), matrix metalloproteinase-13 and A disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS 5) and increased lubricin, collagen II and aggrecan. In parallel, halofuginone-attenuated uncoupled subchondral bone remodelling as defined by reduced subchondral bone tissue volume, lower trabecular pattern factor (Tb.pf) and increased thickness of subchondral bone plate compared with vehicle-treated ACLT controls. We found that halofuginone exerted protective effects in part by suppressing Th17-induced osteoclastic bone resorption, inhibiting Smad2/3-dependent TGF-β signalling to restore coupled bone remodelling and attenuating excessive angiogenesis in subchondral bone. Conclusions Halofuginone attenuates OA progression by inhibition of subchondral bone TGF-β activity and aberrant angiogenesis as a potential preventive therapy for OA.
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Affiliation(s)
- Zhuang Cui
- Department of Orthopaedic Surgery, Institute for Cell Engineering, Johns Hopkins University, Baltimore, Maryland, USA Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Janet Crane
- Department of Orthopaedic Surgery, Institute for Cell Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Hui Xie
- Department of Orthopaedic Surgery, Institute for Cell Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Xin Jin
- Department of Orthopaedic Surgery, Institute for Cell Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Gehua Zhen
- Department of Orthopaedic Surgery, Institute for Cell Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Changjun Li
- Department of Orthopaedic Surgery, Institute for Cell Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Liang Xie
- Department of Orthopaedic Surgery, Institute for Cell Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Long Wang
- Department of Orthopaedic Surgery, Institute for Cell Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Qin Bian
- Department of Orthopaedic Surgery, Institute for Cell Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Tao Qiu
- Department of Orthopaedic Surgery, Institute for Cell Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Mei Wan
- Department of Orthopaedic Surgery, Institute for Cell Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Min Xie
- Department of Pharmaceutical Chemistry, Gladstone Institute of Cardiovascular Disease, University of California, San Francisco, California, USA
| | - Sheng Ding
- Department of Pharmaceutical Chemistry, Gladstone Institute of Cardiovascular Disease, University of California, San Francisco, California, USA
| | - Bin Yu
- Department of Orthopaedics and Traumatology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Xu Cao
- Department of Orthopaedic Surgery, Institute for Cell Engineering, Johns Hopkins University, Baltimore, Maryland, USA
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Lu A, Poddar M, Tang Y, Proto JD, Sohn J, Mu X, Oyster N, Wang B, Huard J. Rapid depletion of muscle progenitor cells in dystrophic mdx/utrophin-/- mice. Hum Mol Genet 2014; 23:4786-800. [PMID: 24781208 DOI: 10.1093/hmg/ddu194] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Duchenne muscular dystrophy (DMD) patients lack dystrophin from birth; however, muscle weakness becomes apparent only at 3-5 years of age, which happens to coincide with the depletion of the muscle progenitor cell (MPC) pools. Indeed, MPCs isolated from older DMD patients demonstrate impairments in myogenic potential. To determine whether the progression of muscular dystrophy is a consequence of the decline in functional MPCs, we investigated two animal models of DMD: (i) dystrophin-deficient mdx mice, the most commonly utilized model of DMD, which has a relatively mild dystrophic phenotype and (ii) dystrophin/utrophin double knock-out (dKO) mice, which display a similar histopathologic phenotype to DMD patients. In contrast to age-matched mdx mice, we observed that both the number and regeneration potential of dKO MPCs rapidly declines during disease progression. This occurred in MPCs at both early and late stages of myogenic commitment. In fact, early MPCs isolated from 6-week-old dKO mice have reductions in proliferation, resistance to oxidative stress and multilineage differentiation capacities compared with age-matched mdx MPCs. This effect may potentially be mediated by fibroblast growth factor overexpression and/or a reduction in telomerase activity. Our results demonstrate that the rapid disease progression in the dKO model is associated, at least in part, with MPC depletion. Therefore, alleviating MPC depletion could represent an approach to delay the onset of the histopathologies associated with DMD patients.
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Affiliation(s)
- Aiping Lu
- Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Minakshi Poddar
- Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Ying Tang
- Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Jonathan D Proto
- Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Jihee Sohn
- Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Xiaodong Mu
- Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Nicholas Oyster
- Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Bing Wang
- Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA 15219, USA
| | - Johnny Huard
- Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA 15219, USA
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Motor physical therapy affects muscle collagen type I and decreases gait speed in dystrophin-deficient dogs. PLoS One 2014; 9:e93500. [PMID: 24713872 PMCID: PMC3979701 DOI: 10.1371/journal.pone.0093500] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 03/07/2014] [Indexed: 11/19/2022] Open
Abstract
Golden Retriever Muscular Dystrophy (GRMD) is a dystrophin-deficient canine model genetically homologous to Duchenne Muscular Dystrophy (DMD) in humans. Muscular fibrosis secondary to cycles of degeneration/regeneration of dystrophic muscle tissue and muscular weakness leads to biomechanical adaptation that impairs the quality of gait. Physical therapy (PT) is one of the supportive therapies available for DMD, however, motor PT approaches have controversial recommendations and there is no consensus regarding the type and intensity of physical therapy. In this study we investigated the effect of physical therapy on gait biomechanics and muscular collagen deposition types I and III in dystrophin-deficient dogs. Two dystrophic dogs (treated dogs-TD) underwent a PT protocol of active walking exercise, 3×/week, 40 minutes/day, 12 weeks. Two dystrophic control dogs (CD) maintained their routine of activities of daily living. At t0 (pre) and t1 (post-physical therapy), collagen type I and III were assessed by immunohistochemistry and gait biomechanics were analyzed. Angular displacement of shoulder, elbow, carpal, hip, stifle and tarsal joint and vertical (Fy), mediolateral (Fz) and craniocaudal (Fx) ground reaction forces (GRF) were assessed. Wilcoxon test was used to verify the difference of biomechanical variables between t0 and t1, considering p<.05. Type I collagen of endomysium suffered the influence of PT, as well as gait speed that had decreased from t0 to t1 (p<.000). The PT protocol employed accelerates morphological alterations on dystrophic muscle and promotes a slower velocity of gait. Control dogs which maintained their routine of activities of daily living seem to have found a better balance between movement and preservation of motor function.
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Cabello-Verrugio C, Morales MG, Cabrera D, Vio CP, Brandan E. Angiotensin II receptor type 1 blockade decreases CTGF/CCN2-mediated damage and fibrosis in normal and dystrophic skeletal muscles. J Cell Mol Med 2012; 16:752-64. [PMID: 21645240 PMCID: PMC3822846 DOI: 10.1111/j.1582-4934.2011.01354.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Connective tissue growth factor (CTGF/CCN-2) is mainly involved in the induction of extracellular matrix (ECM) proteins. The levels of CTGF correlate with the degree and severity of fibrosis in many tissues, including dystrophic skeletal muscle. The CTGF overexpression in tibialis anterior skeletal muscle using an adenoviral vector reproduced many of the features observed in dystrophic muscles including muscle damage and regeneration, fibrotic response and decrease in the skeletal muscle strength. The renin-angiotensin system is involved in the genesis and progression of fibrotic diseases through its main fibrotic components angiotensin-II and its transducer receptor AT-1. The use of AT-1 receptor blockers (ARB) has been shown to decrease fibrosis. In this paper, we show the effect of AT-1 receptor blockade on CTGF-dependent biological activity in skeletal muscle cells as well as the response to CTGF overexpression in normal skeletal muscle. Our results show that in myoblasts ARB decreased CTGF-mediated increase of ECM protein levels, extracellular signal regulated kinases 1/2 (ERK-1/2) phosphorylation and stress fibres formation. In tibialis anterior muscle overexpressing CTGF using an adenovirus, ARB treatment decreased CTGF-mediated increase of ECM molecules, α-SMA and ERK-1/2 phosphorylation levels. Quite remarkable, ARB was able to prevent the loss of contractile force of tibialis anterior muscles overexpressing CTGF. Finally, we show that ARB decreased the levels of fibrotic proteins, CTGF and ERK-1/2 phosphorylation augmented in a dystrophic skeletal muscle from mdx mice. We propose that ARB is a novel pharmacological tool that can be used to decrease the fibrosis induced by CTGF in skeletal muscle associated with muscular dystrophies.
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Affiliation(s)
- Claudio Cabello-Verrugio
- Laboratorio de Diferenciación Celular y Patología, Centro de Regulación Celular y Patología (CRCP), Departamento de Biología Celular y Molecular, Pontificia Universidad Católica de Chile, Santiago, Chile.
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Elashry MI, Collins-Hooper H, Vaiyapuri S, Patel K. Characterisation of connective tissue from the hypertrophic skeletal muscle of myostatin null mice. J Anat 2012; 220:603-11. [PMID: 22463481 DOI: 10.1111/j.1469-7580.2012.01503.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Myostatin is a potent inhibitor of muscle development. Genetic deletion of myostatin in mice results in muscle mass increase, with muscles often weighing three times their normal values. Contracting muscle transfers tension to skeletal elements through an elaborate connective tissue network. Therefore, the connective tissue of skeletal muscle is an integral component of the contractile apparatus. Here we examine the connective tissue architecture in myostatin null muscle. We show that the hypertrophic muscle has decreased connective tissue content compared with wild-type muscle. Secondly, we show that the hypertrophic muscle fails to show the normal increase in muscle connective tissue content during ageing. Therefore, genetic deletion of myostatin results in an increase in contractile elements but a decrease in connective tissue content. We propose a model based on the contractile profile of muscle fibres that reconciles this apparent incompatible tissue composition phenotype.
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Yang Q, Tang Y, Imbrogno K, Lu A, Proto JD, Chen A, Guo F, Fu FH, Huard J, Wang B. AAV-based shRNA silencing of NF-κB ameliorates muscle pathologies in mdx mice. Gene Ther 2012; 19:1196-204. [DOI: 10.1038/gt.2011.207] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Inhibition of the IKK/NF-κB pathway by AAV gene transfer improves muscle regeneration in older mdx mice. Gene Ther 2010; 17:1476-83. [PMID: 20720575 DOI: 10.1038/gt.2010.110] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The IκB kinase (IKKα, β and the regulatory subunit IKKγ) complex regulates nuclear factor of κB (NF-κB) transcriptional activity, which is upregulated in many chronic inflammatory diseases. NF-κB signaling promotes inflammation and limits muscle regeneration in Duchenne muscular dystrophy (DMD), resulting in fibrotic and fatty tissue replacement of muscle that exacerbates the wasting process in dystrophic muscles. Here, we examined whether dominant-negative forms of IKKα (IKKα-dn) and IKKβ (IKKβ-dn) delivered by adeno-associated viral (AAV) vectors to the gastrocnemius (GAS) and tibialis anterior (TA) muscles of 1, 2 and 11-month-old mdx mice, a murine DMD model, block NF-κB activation and increase muscle regeneration. At 1 month post-treatment, the levels of nuclear NF-κB in locally treated muscle were decreased by gene transfer with either AAV-CMV-IKKα-dn or AAV-CMV-IKKβ-dn, but not by IKK wild-type controls (IKKα and β) or phosphate-buffered saline (PBS). Although treatment with AAV-IKKα-dn or AAV-IKKβ-dn vectors had no significant effect on muscle regeneration in young mdx mice treated at 1 and 2 months of age and collected 1 month later, treatment of old (11 months) mdx with AAV-CMV-IKKα-dn or AAV-CMV-IKKβ-dn significantly increased levels of muscle regeneration. In addition, there was a significant decrease in myofiber necrosis in the AAV-IKKα-dn- and AAV-IKKβ-dn-treated mdx muscle in both young and old mice. These results demonstrate that inhibition of IKKα or IKKβ in dystrophic muscle reduces the adverse effects of NF-κB signaling, resulting in a therapeutic effect. Moreover, these results clearly demonstrate the therapeutic benefits of inhibiting NF-κB activation by AAV gene transfer in dystrophic muscle to promote regeneration, particularly in older mdx mice, and block necrosis.
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