rAAV‐mediated combined gene transfer and overexpression of TGF‐β and SOX9 remodels human osteoarthritic articular cartilage

Abstract

Direct administration of therapeutic candidate gene sequences using the safe and effective recombinant adeno-associated virus (rAAV) vectors is a promising strategy to stimulate the biologic activities of articular chondrocytes as an adapted tool to treat human osteoarthritic (OA) cartilage. In the present study, we developed a combined gene transfer approach based on the co-delivery of the pleiotropic transformation growth factor beta (TGF-β) with the specific transcription factor SOX9 via rAAV to human normal and OA chondrocytes in vitro and cartilage explants in situ in light of the mitogenic and pro-anabolic properties of these factors. Effective, durable co-overexpression of TGF-β and SOX9 significantly enhanced the levels of cell proliferation both in human normal and OA chondrocytes and cartilage explants over an extended period of time (21 days), while stimulating the biosynthesis of key matrix components (proteoglycans, type-II collagen) compared with control conditions (reporter lacZ gene transfer, absence of vector treatment). Of further note, expression of hypertrophic type-X collagen significantly decreased following co-treatment by the candidate vectors. The present findings show the value of combining the transfer and expression of potent candidate factors in human OA cartilage as a means to re-establish essential features of normal cartilage and counteract the pathological shift of homeostasis. These observations support the concept of developing dual therapeutic rAAV gene transfer strategies as future, adapted tools for the direct treatment of human OA. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:2181-2190, 2016.

Therapeutic Delivery of rAAV sox9 via Polymeric Micelles Counteracts the Effects of Osteoarthritis-Associated Inflammatory Cytokines in Human Articular Chondrocytes

“…rAAV-FLAG-h sox9 is derived from pSSV9, an AAV-2 genomic clone [ 25 , 26 ], and carries a FLAG-tagged human sox9 cDNA under the control of the cytomegalovirus immediate-early (CMV-IE) promoter [ 23 , 27 , 28 , 29 ]. The vectors were packaged using a helper-free, two-plasmid transfection system in 293 cells with the Adenovirus helper plasmid pXX6 and the packaging plasmid pXX2 [ 18 ].…”

Repair of Damaged Articular Cartilage: Current Approaches and Future Directions

“…Intra-articular delivery of genes coding soluble interleukin 1 (IL-1) receptor (IL-1Ra), IL-10, TGF-β1, and Sox9 reduced the inflammatory process and promoted the regeneration of cartilage tissue [8,182]. The ex vivo transfection of synovial fibroblasts with an IL-1Ra-expressing vector following their re-implantation prevents leukocyte infiltration and cartilage tissue degradation, and this therapy (sc-rAAV2.5IL-1Ra, Mayo Clinic, Rochester, MN, USA) was approved for a Phase I clinical trial in the United States [7,9].…”

“…For people above 65 years of age, this incidence rises to 49.7% (World Health Organization (WHO) statistics 2010), and these numbers continue rising in connection with the aging of the society and an escalating epidemic of obesity. Current treatments of knee and hip OA include cyclooxygenase 2 (COX-2)-selective [7] and nonselective nonsteroidal anti-inflammatory drugs (NSAIDs), as well as intra-articular injections of corticosteroids [8,9], thereby focusing on reducing pain and inflammation without addressing the underlying causes, which eventually leads to joint replacement surgery. The etiology of OA is not yet understood completely; however, aging, trauma, genetic predisposition, obesity, inflammation, and the metabolic syndrome are known to be involved in this disease [10].…”

Interleukin-1 receptor antagonist protein (IL-1Ra) and miR-140 overexpression via pNNS-conjugated chitosan-mediated gene transfer enhances the repair of full-thickness cartilage defects in a rabbit model

“…Currently, gene therapy has attracted more attention and has become a popular research topic. 1-5 Choosing the gene delivery method is very important for gene therapy, and many studies have been undertaken to develop safe and efficient gene delivery methods. 2-7 Chitosan (CS), a polycationic non-viral gene carrier, has been studied by many researchers.…”

“…Therefore, therapy with multiple recombinant genes may improve functional repair, and many studies have combined multiple genes to treat cartilage defects. 5,10,14,15 Several cytokines play important roles in the metabolism of normal cartilage. Because of the chondroregenerative effects of cytokines, many genes coding for insulin-like growth factor I (IGF-I), 1-3,10,11,14 transforming growth factor-β (TGF-β), 5,14,15 transcription factor SOX9, 1,5 and interleukin-1 receptor antagonist protein (IL-1Ra) 10,15 have been transferred into chondrocytes both in vitro and in vivo .…”