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Hu X, Meister R, Tode J, Framme C, Fuchs H. Long-term in vitro monitoring of AAV-transduction efficiencies in real-time with Hoechst 33342. PLoS One 2024; 19:e0298173. [PMID: 38427668 PMCID: PMC10906819 DOI: 10.1371/journal.pone.0298173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 01/19/2024] [Indexed: 03/03/2024] Open
Abstract
Adeno-associated viral transduction allows the introduction of nucleic fragments into cells and is widely used to modulate gene expressions in vitro and in vivo. It enables the study of genetic functions and disease mechanisms and, more recently, serves as a tool for gene repair. To achieve optimal transduction performance for a given cell type, selecting an appropriate serotype and the number of virus particles per cell, also known as the multiplicity of infection, is critical. Fluorescent proteins are one of the common reporter genes to visualize successfully transduced cells and assess transduction efficiencies. Traditional methods of measuring fluorescence-positive cells are endpoint analysis by flow cytometry or manual counting with a fluorescence microscope. However, the flow cytometry analysis does not allow further measurement in a test run, and manual counting by microscopy is time-consuming. Here, we present a method that repeatedly evaluates transduction efficiencies by adding the DNA-stain Hoechst 33342 during the transduction process combined with a microscope or live-cell imager and microplate image analysis software. The method achieves fast, high-throughput, reproducible, and real-time post-transduction analysis and allows for optimizing transduction parameters and screening for a proper approach.
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Affiliation(s)
- Xiaonan Hu
- Institute of Ophthalmology, University Eye Hospital, Hannover Medical School, Hannover, Germany
| | - Roland Meister
- Institute of Ophthalmology, University Eye Hospital, Hannover Medical School, Hannover, Germany
| | - Jan Tode
- Institute of Ophthalmology, University Eye Hospital, Hannover Medical School, Hannover, Germany
| | - Carsten Framme
- Institute of Ophthalmology, University Eye Hospital, Hannover Medical School, Hannover, Germany
| | - Heiko Fuchs
- Institute of Ophthalmology, University Eye Hospital, Hannover Medical School, Hannover, Germany
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Serotype-specific transduction of canine joint tissue explants and cultured monolayers by self-complementary adeno-associated viral vectors. Gene Ther 2022; 30:398-404. [PMID: 36261499 DOI: 10.1038/s41434-022-00366-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 08/04/2022] [Accepted: 09/14/2022] [Indexed: 11/08/2022]
Abstract
A formal screening of self-complementary adeno-associated virus (scAAV) vector serotypes in canine joint tissues has not been performed to date. Selecting appropriate serotypes is crucial for successful treatment due to their varying levels of tissue tropism. The objective of this study is to identify the most optimal scAAV vector serotype that maximizes transduction efficiencies in canine cell monolayer cultures (chondrocytes, synoviocytes, and mesenchymal stem cells) and tissue explant cultures (cartilage and synovium). Transduction efficiencies of scAAV serotypes 1, 2, 2.5, 3, 4, 5, 6, 8, and 9 were evaluated in each culture type in three different vector concentrations by encoding a green fluorescent protein. It was found that scAAV2 and 2.5 showed the overall highest transduction efficiency among serotypes with dose-response. Since possible immune response against conventional AAV2 was previously reported in dogs, the chimeric scAAV2.5 may be more suitable to use. Evaluation of the safety and efficacy of the scAAV2.5 vector with an appropriate therapeutic gene in vivo is indicated.
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Mehta V, Ofir K, Swanson A, Kloczko E, Boyd M, Barker H, Avdic-Belltheus A, Martin J, Zachary I, Peebles D, David AL. Gene Targeting to the Uteroplacental Circulation of Pregnant Guinea Pigs. Reprod Sci 2016; 23:1087-95. [PMID: 26865541 DOI: 10.1177/1933719116630411] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Our study aimed to target adenoviral gene therapy to the uteroplacental circulation of pregnant guinea pigs in order to develop a novel therapy for fetal growth restriction. Four methods of delivery of an adenovirus encoding β-galactosidase (Ad.LacZ) were evaluated: intravascular injection using phosphate-buffered saline (PBS) into (1) uterine artery (UtA) or (2) internal iliac artery or external administration in (3) PBS or (4) pluronic F-127 gel (Sigma Aldrich). Postmortem examination was performed 4 to 7 days after gene transfer. Tissue transduction was assessed by X-gal histochemistry and enzyme-linked immunosorbent assay. External vascular application of the adenovirus vector in combination with pluronic gel had 91.7% success rate in terms of administration (85% maternal survival) and gave the best results for maternal/fetal survival and local transduction efficiency without any spread to maternal or fetal tissues. This study suggests an optimal method of gene delivery to the UtAs of a small rodent for preclinical studies.
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Affiliation(s)
- Vedanta Mehta
- Institute for Women's Health, University College London, London, United Kingdom Centre for Cardiovascular Biology and Medicine, University College London, London, United Kingdom
| | - Keren Ofir
- Institute for Women's Health, University College London, London, United Kingdom
| | - Anna Swanson
- Institute for Women's Health, University College London, London, United Kingdom
| | - Ewa Kloczko
- Institute for Women's Health, University College London, London, United Kingdom
| | - Michael Boyd
- BSU, Royal Veterinary College, London, United Kingdom
| | - Hannah Barker
- BSU, Royal Veterinary College, London, United Kingdom
| | | | - John Martin
- Centre for Cardiovascular Biology and Medicine, University College London, London, United Kingdom
| | - Ian Zachary
- Centre for Cardiovascular Biology and Medicine, University College London, London, United Kingdom
| | - Donald Peebles
- Institute for Women's Health, University College London, London, United Kingdom
| | - Anna L David
- Institute for Women's Health, University College London, London, United Kingdom
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Use of Tissue Engineering Strategies to Repair Joint Tissues in Osteoarthritis: Viral Gene Transfer Approaches. Curr Rheumatol Rep 2014; 16:449. [DOI: 10.1007/s11926-014-0449-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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In vivo reduction or blockade of interleukin-1β in primary osteoarthritis influences expression of mediators implicated in pathogenesis. Osteoarthritis Cartilage 2012; 20:1610-8. [PMID: 22935786 PMCID: PMC3478416 DOI: 10.1016/j.joca.2012.08.011] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 08/10/2012] [Accepted: 08/18/2012] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Diminish interleukin-1β (IL-1β) signaling in a model of primary osteoarthritis by RNA interference-based transcript reduction or receptor blockade, and quantify changes incurred on transcript expression of additional mediators. METHODS Knees of Hartley guinea pigs were collected at 120 and 180 days of age following injection with viral vectors (N = 4/treatment group/date) at 60 days. Two groups received either adeno-associated viral serotype 5 vector containing a knockdown sequence (TV), or adenoviral vector encoding for IL-1 receptor antagonist protein (Ad-IRAP); treatments were contrasted with opposite knees administered corresponding vector controls. A third group evaluated TV relative to saline-only injected knees. Chondropathy and immunohistochemistry findings were compared to untreated guinea pigs. Transcript expression levels in cartilage were calculated using the comparative CT (2(-ΔΔCT)) method and analyzed by one-way analysis of variance (ANOVA) with pairwise comparisons using Tukey 95% confidence intervals. RESULTS Vector transduction was confirmed at both harvest dates. TV and Ad-IRAP, relative to vector controls, significantly decreased IL-1β. Inflammatory mediators [tumor necrosis factor-α (TNF-α), IL-8, interferon-γ (IFN-γ)], and catabolic matrix metalloproteinase 13 (MMP13) were also decreased, while anabolic transforming growth factor-β1 (TGF-β1) was increased. IL-1β was also decreased by TV vs saline, with a decrease in MMP13 and increase TGF-β1; TNF-α, IL-8, and IFN-γ were transiently increased. CONCLUSIONS This work confirmed that a reduction in IL-1β signaling was accomplished by either method, resulting in decreased expression of three inflammatory mediators and one catabolic agent, and increased expression of an anabolic molecule. Thus, evidence is provided that IL-1β serves a role in vivo in spontaneous osteoarthritis and that these translational tools may provide beneficial disease modification.
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Mason JB, Vandenberghe LH, Xiao R, Wilson JM, Richardson DW. Influence of serotype, cell type, tissue composition, and time after inoculation on gene expression in recombinant adeno-associated viral vector-transduced equine joint tissues. Am J Vet Res 2012; 73:1178-85. [PMID: 22849678 PMCID: PMC10694859 DOI: 10.2460/ajvr.73.8.1178] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/06/2023]
Abstract
OBJECTIVE To evaluate transduction efficiency of gene therapy for treatment of osteoarthritis in horses. SAMPLE Cartilage and synovial tissues were aseptically collected from the stifle joints of 3 Thoroughbreds; horses were 3, 7, and 12 years old and free from sepsis and long-term drug treatment and were euthanized for reasons unrelated to joint disease. PROCEDURES Gene transfer experiments were performed with 8 recombinant adeno-associated viral vector (rAAV) serotypes in monolayer-cultured equine chondrocytes, synovial cells, and mesenchymal stromal cells and in cartilage and synovial tissues. RESULTS Serotypes rAAV2/5 and rAAV2/2 yielded the highest transduction efficiency in cultured cells 6 days after transduction. Synovial cells and mesenchymal stromal cells were more readily transduced than were chondrocytes. Serotype rAAV2/6.2 yielded the highest rate of gene expression in both cartilage and synovial tissues at 6 days after inoculation. However, at 30 and 60 days after inoculation, gene expression of serotypes rAAV2/2 and rAAV2/5 surpassed that of rAAV2/6.2 and all other serotypes. CONCLUSIONS AND CLINICAL RELEVANCE Maximally expressing serotypes changed between 6 and 30 days in tissues; however, the most efficient serotypes for transduction of joint cells over time were also the most efficient serotypes for transduction of joint tissues. In addition, the low transduction efficiency of articular cartilage tissue was paralleled by a low transduction efficiency of isolated chondrocytes. This suggested that the typically low transduction efficiency of articular cartilage may be attributable in part to the low transduction efficiency of the chondrocytes and not solely a result of the dense cartilage matrix.
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Affiliation(s)
- Jeffrey B Mason
- Department of Clinical Studies, University of Pennsylvania, Kennett Square, PA 19348, USA.
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Pohle D, Kasch R, Herlyn P, Bader R, Mittlmeier T, Pützer BM, Müller-Hilke B. Adenoviral transduction supports matrix expression of alginate cultured articular chondrocytes. Biotechnol Bioeng 2012; 109:2402-8. [PMID: 22447406 DOI: 10.1002/bit.24505] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Revised: 02/16/2012] [Accepted: 03/12/2012] [Indexed: 11/06/2022]
Abstract
The present study examines the effects of adenoviral (Ad) transduction of human primary chondrocyte on transgene expression and matrix production. Primary chondrocytes were isolated from healthy articular cartilage and from cartilage with mild osteoarthritis (OA), transduced with an Ad vector and either immediately cultured in alginate or expanded in monolayer before alginate culture. Proteoglycan production was measured using dimethylmethylene blue (DMMB) assay and matrix gene expression was quantified by real-time PCR. Viral infection of primary chondrocytes results in a stable long time transgene expression for up to 13 weeks. Ad transduction does not significantly alter gene expression and matrix production if chondrocytes are immediately embedded in alginate. However, if expanded prior to three dimension (3D) culture in alginate, chondrocytes produce not only more proteoglycans compared to non-transduced controls, but also display an increased anabolic and decreased catabolic activity compared to non-transduced controls. We therefore suggest that successful autologous chondrocyte transplantation (ACT) should combine adenoviral transduction of primary chondrocytes with expansion in monolayer followed by 3D culture. Future studies will be needed to investigate whether the subsequent matrix production can be further improved by using Ad vectors bearing genes encoding matrix proteins.
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Affiliation(s)
- D Pohle
- University of Rostock, Medical Faculty, Institute of Immunology, Rostock, Germany.
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Inflammation and immune response of intra-articular serotype 2 adeno-associated virus or adenovirus vectors in a large animal model. ARTHRITIS 2012; 2012:735472. [PMID: 22288012 PMCID: PMC3263587 DOI: 10.1155/2012/735472] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Accepted: 10/05/2011] [Indexed: 12/02/2022]
Abstract
Intra-articular gene therapy has potential for the treatment of osteoarthritis and rheumatoid arthritis. To quantify in vitro relative gene transduction, equine chondrocytes and synovial cells were treated with adenovirus vectors (Ad), serotype 2 adeno-associated virus vectors (rAAV2), or self-complementary (sc) AAV2 vectors carrying green fluorescent protein (GFP). Using 6 horses, bilateral metacarpophalangeal joints were injected with Ad, rAAV2, or scAAV2 vectors carrying GFP genes to assess the in vivo joint inflammation and neutralizing antibody (NAb) titer in serum and joint fluid. In vitro, the greater transduction efficiency and sustained gene expression were achieved by scAAV2 compared to rAAV2 in equine chondrocytes and synovial cells. In vivo, AAV2 demonstrated less joint inflammation than Ad, but similar NAb titer. The scAAV2 vectors can induce superior gene transduction than rAAV2 in articular cells, and both rAAV2 and scAAV2 vectors were showed to be safer for intra-articular use than Ad vectors.
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Effective reduction of the interleukin-1β transcript in osteoarthritis-prone guinea pig chondrocytes via short hairpin RNA mediated RNA interference influences gene expression of mediators implicated in disease pathogenesis. Osteoarthritis Cartilage 2011; 19:1449-57. [PMID: 21945742 PMCID: PMC3256924 DOI: 10.1016/j.joca.2011.09.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2011] [Revised: 09/06/2011] [Accepted: 09/09/2011] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To ascertain a viral vector-based short hairpin RNA (shRNA) capable of reducing the interleukin-1β (IL-1β) transcript in osteoarthritis (OA)-prone chondrocytes and detect corresponding changes in the expression patterns of several critical disease mediators. METHODS Cultured chondrocytes from 2-month-old Hartley guinea pigs were screened for reduction of the IL-1β transcript following plasmid-based delivery of U6-driven shRNA sequences. A successful plasmid/shRNA knockdown combination was identified and used to construct an adeno-associated virus serotype 5 (AAV5) vector for further evaluation. Relative real-time reverse transcription polymerase chain reaction (RT-PCR) was used to quantify in vitro transcript changes of IL-1β and an additional nine genes following transduction with this targeting knockdown vector. To validate in vitro findings, this AAV5 vector was injected into one knee, while either an equivalent volume of saline vehicle (three animals) or non-targeting control vector (three animals) were injected into opposite knees. Fold differences and subsequent percent gene expression levels relative to control groups were calculated using the comparative CT (2(-ΔΔCT)) method. RESULTS Statistically significant decreases in IL-1β expression were achieved by the targeting knockdown vector relative to both the mock-transduced control and non-targeting vector control groups in vitro. Transcript levels of anabolic transforming growth factor-β (TGF-β) were significantly increased by use of this targeting knockdown vector. Transduction with this targeting AAV5 vector also significantly decreased the transcript levels of key inflammatory cytokines [tumor necrosis factor-α (TNF-α), IL-2, IL-8, and IL-12] and catabolic agents [matrix metalloproteinase (MMP)13, MMP2, interferon-γ (IFN-γ), and inducible nitrous oxide synthase (iNOS)] relative to both mock-transduced and non-targeting vector control groups. In vivo application of this targeting knockdown vector resulted in a >50% reduction (P=0.0045) or >90% (P=0.0001) of the IL-1β transcript relative to vehicle-only or non-targeting vector control exposed cartilage, respectively. CONCLUSIONS Successful reduction of the IL-1β transcript was achieved via RNA interference (RNAi) techniques. Importantly, this alteration significantly influenced the transcript levels of several major players involved in OA pathogenesis in the direction of disease modification. Investigations to characterize additional gene expression changes influenced by targeting knockdown AAV5 vector-based diminution of the IL-1β transcript in vivo are warranted.
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Payne KA, Lee HH, Haleem AM, Martins C, Yuan Z, Qiao C, Xiao X, Chu CR. Single intra-articular injection of adeno-associated virus results in stable and controllable in vivo transgene expression in normal rat knees. Osteoarthritis Cartilage 2011; 19:1058-65. [PMID: 21571082 PMCID: PMC3139006 DOI: 10.1016/j.joca.2011.04.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Revised: 04/14/2011] [Accepted: 04/19/2011] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To test the hypothesis that in vivo transgene expression mediated by single intra-articular injection of adeno-associated virus serotype 2 (AAV2) persists within intra-articular tissues 1 year post-injection and can be externally controlled using an AAV2-based tetracycline-inducible gene regulation system containing the tetracycline response element (TRE) promoter. METHODS Sprague Dawley rats received intra-articular injections of AAV2-cytomegalovirus (CMV)-enhanced green fluorescent protein (GFP) and AAV2-CMV-luciferase (Luc) into their right and left knees, respectively. Luciferase expression was evaluated over 1 year using bioluminescence imaging. After sacrifice, tissues were analyzed for GFP+ cells by fluorescent microscopy. To study external control of intra-articular AAV-transgene expression, another set of rats was co-injected with AAV2-TRE-Luc and AAV2-CMV-reverse-tetracycline-controlled transactivator (rtTA) into the right knees, and AAV2-CMV-Luc and AAV2-CMV-rtTA into the left knees. Rats received oral doxycycline (Dox), an analog of tetracycline, for 7 days. Luciferase expression was assessed by bioluminescence imaging. RESULTS Luciferase expression was localized to the injected joint and persisted throughout the 1-year study period. Abundant GFP+ cells were observed within intra-articular soft tissues. Transgene expression in AAV2-TRE-Luc injected joints was upregulated by oral administration of Dox, and downregulated following its removal, at 14 days and 13 months post-AAV injection. CONCLUSIONS This longitudinal in vivo study shows that sustained and stable AAV-mediated intra-articular transgene expression can be achieved through a single intra-articular injection and can be controlled using a tetracycline-controlled inducible AAV system in a normal rat knee model. Highly regulatable long-term intra-articular transgene expression is of potential clinical utility for development of treatment strategies for chronic intra-articular disease processes such as inflammatory and degenerative arthritis.
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Affiliation(s)
- Karin A. Payne
- Cartilage Restoration Center, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Hannah H. Lee
- Cartilage Restoration Center, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA, Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Amgad M. Haleem
- Cartilage Restoration Center, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Cesar Martins
- Cartilage Restoration Center, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Zhenhua Yuan
- Division of Molecular Pharmaceutics, The Eshelman School of Pharmacy, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, USA
| | - Chunping Qiao
- Division of Molecular Pharmaceutics, The Eshelman School of Pharmacy, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, USA
| | - Xiao Xiao
- Division of Molecular Pharmaceutics, The Eshelman School of Pharmacy, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, USA
| | - Constance R. Chu
- Cartilage Restoration Center, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA, Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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Menendez MI, Clark DJ, Carlton M, Flanigan DC, Jia G, Sammet S, Weisbrode SE, Knopp MV, Bertone AL. Direct delayed human adenoviral BMP-2 or BMP-6 gene therapy for bone and cartilage regeneration in a pony osteochondral model. Osteoarthritis Cartilage 2011; 19:1066-75. [PMID: 21683796 DOI: 10.1016/j.joca.2011.05.007] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Revised: 04/19/2011] [Accepted: 05/17/2011] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To evaluate healing of surgically created large osteochondral defects in a weight-bearing femoral condyle in response to delayed percutaneous direct injection of adenoviral (Ad) vectors containing coding regions for either human bone morphogenetic proteins 2 (BMP-2) or -6. METHODS Four 13mm diameter and 7mm depth circular osteochondral defects were drilled, 1/femoral condyle (n=20 defects in five ponies). At 2 weeks, Ad-BMP-2, Ad-BMP-6, Ad-green fluorescent protein (GFP), or saline was percutaneously injected into the central drill hole of the defect. Quantitative magnetic resonance imaging (qMRI) and computed tomography (CT) were serially performed at 12, 24, and 52 weeks. At 12 (one pony) or 52 weeks, histomorphometry and microtomographic analyses were performed to assess subchondral bone and cartilage repair tissue quality. RESULTS Direct delivery of Ad-BMP-6 demonstrated delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) and histologic evidence of greater Glycosaminoglycan (GAG) content in repair tissue at 12 weeks, while Ad-BMP-2 had greater non-mineral cartilage at the surface at 52 weeks (p<0.04). Ad-BMP-2 demonstrated greater CT subchondral bone mineral density (BMD) by 12 weeks and both Ad-BMP-2 and -6 had greater subchondral BMD at 52 weeks (p<0.05). Despite earlier (Ad-BMP-6) and more persistent (Ad-BMP-2) chondral tissue and greater subchondral bone density (Ad-BMP-2 and -6), the tissue within the large weight-bearing defects at 52 weeks was suboptimal in all groups due to poor quality repair cartilage, central fibrocartilage retention, and central bone cavitation. Delivery of either BMP by this method had greater frequency of subchondral bone cystic formation (p<0.05). CONCLUSIONS Delivery of Ad-BMP-2 or Ad-BMP-6 via direct injection supported cartilage and subchondral bone regeneration but was insufficient to provide long-term quality osteochondral repair.
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Affiliation(s)
- M I Menendez
- Comparative Orthopaedic Research Laboratory, Department of Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA
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Dougherty SS, Santangelo KS, Bertone AL. Evaluation of the ability of two transfection reagents to deliver small interfering RNA molecules to equine and guinea pig cartilage in vitro. Am J Vet Res 2011; 72:813-9. [PMID: 21627528 DOI: 10.2460/ajvr.72.6.813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate 2 commercially available transfection reagents for transfection efficiency and distribution of small interfering RNA (siRNA) molecules to chondrocytes in monolayer cultures and full-thickness cartilage explants from guinea pigs and horses. SAMPLE Cartilage explants from 5 one-month-old and 3 adult guinea pigs and 5 adult clinically normal horses. PROCEDURES Monolayer chondrocytes and uniform cartilage explants were exposed to 1 of 2 siRNA transfection complexes according to manufacturers' protocols (1μM [1×]). Additionally, monolayer chondrocytes were exposed to 2× the suggested amount of a proprietary siRNA molecule. Full-thickness cartilage explants were treated with 1× (1μM), 2× (2μM), and 4× (4μM) or 1× (0.13μM), 4× (0.52μM), and 8× (1.04μM) the recommended concentrations of the proprietary siRNA and the cationic liposome siRNA, respectively, in equivalent media volumes. Use of fluorescent siRNA duplexes allowed quantification of transfected cells via flow cytometry and direct visualization of the depth and distribution of in situ transfection via fluorescent microscopy. RESULTS With both transfection reagents, > 90% of monolayer chondrocytes were transfected. In explants, only use of the proprietary molecule achieved > 50% transfection efficiency, whereas use of the cationic liposome achieved < 20%. Only the proprietary molecule-treated cartilage consistently contained fluorescent cells throughout all zones; the cationic liposome-transfected chondrocytes were restricted to explant surfaces. CONCLUSIONS AND CLINICAL RELEVANCE Robust transfection of chondrocytes in monolayer was achieved with both reagents, but only use of the proprietary molecule attained effective full-thickness transfection of explants that may allow relevant transcript reduction via RNAi.
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Affiliation(s)
- Sarah S Dougherty
- Willamette Valley Equine Surgical and Medical Center, Aurora, OR 97002, USA
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