Adeno-associated virus gene therapy vector scAAVIGF-I for transduction of equine articular chondrocytes and RNA-seq analysis

Temporal insights into molecular and cellular responses during rAAV production in HEK293T cells

The gene therapy field seeks cost-effective, large-scale production of recombinant adeno-associated virus (rAAV) vectors for high-dosage therapeutic applications. Although strategies like suspension cell culture and transfection optimization have shown moderate success, challenges persist for large-scale applications. To unravel molecular and cellular mechanisms influencing rAAV production, we conducted an SWATH-MS proteomic analysis of HEK293T cells transfected using standard, sub-optimal, and optimal conditions. Gene Ontology and pathway analysis revealed significant protein expression variations, particularly in processes related to cellular homeostasis, metabolic regulation, vesicular transport, ribosomal biogenesis, and cellular proliferation under optimal transfection conditions. This resulted in a 50% increase in rAAV titer compared with the standard protocol. Additionally, we identified modifications in host cell proteins crucial for AAV mRNA stability and gene translation, particularly regarding AAV capsid transcripts under optimal transfection conditions. Our study identified 124 host proteins associated with AAV replication and assembly, each exhibiting distinct expression pattern throughout rAAV production stages in optimal transfection condition. This investigation sheds light on the cellular mechanisms involved in rAAV production in HEK293T cells and proposes promising avenues for further enhancing rAAV titer during production.

A pilot study to determine the optimal dose of scAAVIL-1ra in a large animal model of post-traumatic osteoarthritis

Gene therapy approaches using adeno-associated viral vectors have been successfully tested in the equine post-traumatic osteoarthritis (PTOA) model. Owing to differences in the levels of transgene expression and adverse tissue reactions observed in published studies, we sought to identify a safe therapeutic dose of scAAVIL-1ra in an inflamed and injured joint that would result in improved functional outcomes without any adverse events. scAAVIL-1ra was delivered intra-articularly over a 100-fold range, and horses were evaluated throughout and at the end of the 10-week study. A dose-related increase in IL-1ra levels with a decrease in PGE2 levels was observed, with the peak IL-1ra concentration being observed 7 days post-treatment in all groups. Perivascular infiltration with mononuclear cells was observed within the synovial membrane of the joint treated with the highest viral dose of 5 × 1012 vg, but this was absent in the lower-dosed joints. The second-highest dose of scAAVeqIL-1ra 5 × 1011 vg demonstrated elevated IL-1ra levels without any cellular response in the synovium. Taken together, the data suggest that the 10-fold lower dose of 5 × 1011vg scAAVIL-1ra would be a safe therapeutic dose in an equine model of PTOA.

New treatment for osteoarthr: pbad014itis: Gene therapy

Osteoarthritis is a complex degenerative disease that affects the entire joint tissue. Currently, non-surgical treatments for osteoarthritis focus on relieving pain. While end-stage osteoarthritis can be treated with arthroplasty, the health and financial costs associated with surgery have forced the search for alternative non-surgical treatments to delay the progression of osteoarthritis and promote cartilage repair. Unlike traditional treatment, the gene therapy approach allows for long-lasting expression of therapeutic proteins at specific sites. In this review, we summarize the history of gene therapy in osteoarthritis, outlining the common expression vectors (non-viral, viral), the genes delivered (transcription factors, growth factors, inflammation-associated cytokines, non-coding RNAs) and the mode of gene delivery (direct delivery, indirect delivery). We highlight the application and development prospects of the gene editing technology CRISPR/Cas9 in osteoarthritis. Finally, we identify the current problems and possible solutions in the clinical translation of gene therapy for osteoarthritis.

Administration and detection of gene therapy in horses: A systematic review

Gene therapy uses genetic modification of cells to produce a therapeutic effect. Defective or missing genes can be repaired or replaced, or gene expression can be modified using a variety of technologies. Repair of defective genes can be achieved using specialized gene editing tools. Gene addition promotes gene expression by introducing synthetic copies of genes of interest (transgenes) into cells where they are transcribed and translated into therapeutic proteins. Protein production can also be modified using therapies that regulate gene expression. Gene therapy is currently prohibited in both human and equine athletes because of the potential to induce production of performance-enhancing proteins in the athlete's body, also referred to as "gene doping." Detection of gene doping is challenging and necessitates development of creative, novel analytical methods for doping control. Methods for detection of gene doping must be specific to and will vary depending on the type of gene therapy. The purpose of this paper is to present the results of a systematic review of gene editing, gene therapy, and detection of gene doping in horses. Based on the published literature, gene therapy has been administered to horses in a large number of experimental studies and a smaller number of clinical cases. Detection of gene therapy is possible using a combination of PCR and sequencing technologies. This summary can provide a basis for discussion of appropriate and inappropriate uses for gene therapy in horses by the veterinary community and guide expansion of methods to detect inappropriate uses by the regulatory community.

Gene therapy approaches for equine osteoarthritis

With an intrinsically low ability for self-repair, articular cartilage injuries often progress to cartilage loss and joint degeneration resulting in osteoarthritis (OA). Osteoarthritis and the associated articular cartilage changes can be debilitating, resulting in lameness and functional disability both in human and equine patients. While articular cartilage damage plays a central role in the pathogenesis of OA, the contribution of other joint tissues to the pathogenesis of OA has increasingly been recognized thus prompting a whole organ approach for therapeutic strategies. Gene therapy methods have generated significant interest in OA therapy in recent years. These utilize viral or non-viral vectors to deliver therapeutic molecules directly into the joint space with the goal of reprogramming the cells' machinery to secrete high levels of the target protein at the site of injection. Several viral vector-based approaches have demonstrated successful gene transfer with persistent therapeutic levels of transgene expression in the equine joint. As an experimental model, horses represent the pathology of human OA more accurately compared to other animal models. The anatomical and biomechanical similarities between equine and human joints also allow for the use of similar imaging and diagnostic methods as used in humans. In addition, horses experience naturally occurring OA and undergo similar therapies as human patients and, therefore, are a clinically relevant patient population. Thus, further studies utilizing this equine model would not only help advance the field of human OA therapy but also benefit the clinical equine patients with naturally occurring joint disease. In this review, we discuss the advancements in gene therapeutic approaches for the treatment of OA with the horse as a relevant patient population as well as an effective and commonly utilized species as a translational model.

Low-Input RNA-Sequencing in Patients with Cartilage Lesions, Osteoarthritis, and Healthy Cartilage

OBJECTIVE

To analyze and compare cartilage samples from 3 groups of patients utilizing low-input RNA-sequencing.

DESIGN

Cartilage biopsies were collected from patients in 3 groups (n = 48): Cartilage lesion (CL) patients had at least ICRS grade 2, osteoarthritis (OA) samples were taken from patients undergoing knee replacement, and healthy cartilage (HC) was taken from ACL-reconstruction patients without CLs. RNA was isolated using an optimized protocol. RNA samples were assessed for quality and sequenced with a low-input SmartSeq2 protocol.

RESULTS

RNA isolation yielded 48 samples with sufficient quality for sequencing. After quality control, 13 samples in the OA group, 9 in the HC group, and 9 in the CL group were included in the analysis. There was a high degree of co-clustering between the HC and CL groups with only 6 genes significantly up- or downregulated. OA and the combined HC/CL group clustered significantly separate from each other, yielding 659 significantly upregulated and 1,369 downregulated genes. GO-term analysis revealed that genes matched to cartilage and connective tissue development terms.

CONCLUSION

The gene expression profiles from the 3 groups suggest that there are no major differences in gene expression between cartilage from knees with a cartilage injury and knees without an apparent cartilage injury. OA cartilage, as expected, showed markedly different gene expression from the other 2 groups. The gene expression profiles resulting from this low-input RNA-sequencing study offer opportunities to discover new pathways not previously recognized that may be explored in future studies.

The Concentration of Plasma Provides Additional Bioactive Proteins in Platelet and Autologous Protein Solutions

BACKGROUND

Currently, platelet-poor plasma (PPP) is a discarded waste product of platelet-rich plasma (PRP) and may contain valuable proteins.

PURPOSE/HYPOTHESIS

The study's goal was to evaluate the concentration of plasma as a potential additive biotherapy for the treatment of osteoarthritis. We hypothesized that a novel polyacrylamide concentration device would efficiently concentrate insulin-like growth factor-1 (IGF-1) from PPP and be additive to PRP or autologous protein solution (APS).

STUDY DESIGN

Descriptive laboratory study.

METHODS

A laboratory study was conducted with human and equine whole blood from healthy volunteers/donors. Fresh samples of blood and plasma were processed and characterized for platelet, white blood cell, and growth factor/cytokine content and then quantified by enzyme-linked immunosorbent assays specific for IGF-1, transforming growth factor-β, interleukin-1β, and interleukin-1 receptor antagonist as representatives of cartilage anabolic and inflammatory mediators.

RESULTS

A potent cartilage anabolic protein, IGF-1, was significantly concentrated by the polyacrylamide concentration device in both human and equine PPP. The polyacrylamide device also substantially increased plasma proteins over whole blood, most dramatically key proteins relevant to the treatment of osteoarthritis, including transforming growth factor-β (29-fold over blood) and interleukin-1 receptor antagonist (70-fold over plasma).

CONCLUSION

Concentrated PPP is a unique source for biologically relevant concentrations of IGF-1. PRP and APS can produce greater concentrations of other anabolic and anti-inflammatory proteins not found in plasma.

CLINICAL RELEVANCE

The polyacrylamide device efficiently concentrated PPP to create a unique source of IGF-1 that may supplement orthopaedic biologic therapies.

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

Objectives

Previously, we reported the improved transfection efficiency of a plasmid DNA-chitosan (pDNA-CS) complex using a phosphorylatable nuclear localization signal-linked nucleic kinase substrate short peptide (pNNS) conjugated to chitosan (pNNS-CS). This study investigated the effects of pNNS-CS-mediated miR-140 and interleukin-1 receptor antagonist protein (IL-1Ra) gene transfection both in rabbit chondrocytes and a cartilage defect model.

Methods

The pBudCE4.1-miR-140, pBudCE4.1-IL-1Ra, and negative control pBudCE4.1 plasmids were constructed and combined with pNNS-CS to form pDNA/pNNS-CS complexes. These complexes were transfected into chondrocytes or injected into the knee joint cavity.

Results

High IL-1Ra and miR-140 expression levels were detected both in vitro and in vivo. In vitro, compared with the pBudCE4.1 group, the transgenic group presented with significantly increased chondrocyte proliferation and glycosaminoglycan (GAG) synthesis, as well as increased collagen type II alpha 1 chain (COL2A1), aggrecan (ACAN), and TIMP metallopeptidase inhibitor 1 (TIMP-1) levels. Nitric oxide (NO) synthesis was reduced, as were a disintegrin and metalloproteinase with thrombospondin type 1 motif 5 (ADAMTS-5) and matrix metalloproteinase (MMP)-13 levels. In vivo, the exogenous genes reduced the synovial fluid GAG and NO concentrations and the ADAMTS-5 and MMP-13 levels in cartilage. In contrast, COL2A1, ACAN, and TIMP-1 levels were increased, and the cartilage Mankin score was decreased in the transgenic group compared with the pBudCE4.1 group. Double gene combination produced greater efficacies than each single gene, both in vitro and in vivo.

Conclusion

This study suggests that pNNS-CS is a good candidate for treating cartilage defects via gene therapy, and that IL-1Ra in combination with miR-140 produces promising biological effects on cartilage defects.

Cite this article: R. Zhao, S. Wang, L. Jia, Q. Li, J. Qiao, X. Peng. 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. Bone Joint Res 2019;8:165–178. DOI: 10.1302/2046-3758.83.BJR-2018-0222.R1.

Biomarkers for equine joint injury and osteoarthritis

We report the results of a symposium aimed at identifying validated biomarkers that can be used to complement clinical observations for diagnosis and prognosis of joint injury leading to equine osteoarthritis (OA). Biomarkers might also predict pre-fracture change that could lead to catastrophic bone failure in equine athletes. The workshop was attended by leading scientists in the fields of equine and human musculoskeletal biomarkers to enable cross-disciplinary exchange and improve knowledge in both. Detailed proceedings with strategic planning was written, added to, edited and referenced to develop this manuscript. The most recent information from work in equine and human osteoarthritic biomarkers was accumulated, including the use of personalized healthcare to stratify OA phenotypes, transcriptome analysis of anterior cruciate ligament (ACL) and meniscal injuries in the human knee. The spectrum of "wet" biomarker assays that are antibody based that have achieved usefulness in both humans and horses, imaging biomarkers and the role they can play in equine and human OA was discussed. Prediction of musculoskeletal injury in the horse remains a challenge, and the potential usefulness of spectroscopy, metabolomics, proteomics, and development of biobanks to classify biomarkers in different stages of equine and human OA were reviewed. The participants concluded that new information and studies in equine musculoskeletal biomarkers have potential translational value for humans and vice versa. OA is equally important in humans and horses, and the welfare issues associated with catastrophic musculoskeletal injury in horses add further emphasis to the need for good validated biomarkers in the horse. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:823-831, 2018.

Therapeutic advances in musculoskeletal AAV targeting approaches

The use of recombinant adeno-associated viruses (rAAVs) is highly prevalent in musculoskeletal gene therapies due to their versatility, high transduction efficiency, natural tropism and vector genome persistence for years. As the largest organ in the body, treatment of skeletal muscle for widespread and sufficient therapeutic gene expression is highly challenging. In addition to disease-specific hurdles, vector genome loss, off-target gene transfer and immune responses to treatment can diminish the overall benefit of rAAV therapies. A variety of approaches have been developed to overcome these challenges and improve musculoskeletal targeting of rAAVs. This review focuses on recent advancements and remaining obstacles in creating optimal rAAV-based therapies for musculoskeletal application.

Peripheral blood aspirates overexpressing IGF-I via rAAV gene transfer undergo enhanced chondrogenic differentiation processes

Implantation of peripheral blood aspirates induced towards chondrogenic differentiation upon genetic modification in sites of articular cartilage injury may represent a powerful strategy to enhance cartilage repair. Such a single‐step approach may be less invasive than procedures based on the use of isolated or concentrated MSCs, simplifying translational protocols in patients. In this study, we provide evidence showing the feasibility of overexpressing the mitogenic and pro‐anabolic insulin‐like growth factor I (IGF‐I) in human peripheral blood aspirates via rAAV‐mediated gene transfer, leading to enhanced proliferative and chondrogenic differentiation (proteoglycans, type‐II collagen, SOX9) activities in the samples relative to control (reporter rAAV‐lacZ) treatment over extended periods of time (at least 21 days, the longest time‐point evaluated). Interestingly, IGF‐I gene transfer also triggered hypertrophic, osteo‐ and adipogenic differentiation processes in the aspirates, suggesting that careful regulation of IGF‐I expression may be necessary to contain these events in vivo. Still, the current results demonstrate the potential of targeting human peripheral blood aspirates via therapeutic rAAV transduction as a novel, convenient tool to treat articular cartilage injuries.

Insights on Molecular Mechanisms of Chondrocytes Death in Osteoarthritis

Osteoarthritis (OA) is a joint pathology characterized by progressive cartilage degradation. Medical care is mainly based on alleviating pain symptoms. Compelling studies report the presence of empty lacunae and hypocellularity in cartilage with aging and OA progression, suggesting that chondrocyte cell death occurs and participates to OA development. However, the relative contribution of apoptosis per se in OA pathogenesis appears complex to evaluate. Indeed, depending on technical approaches, OA stages, cartilage layers, animal models, as well as in vivo or in vitro experiments, the percentage of apoptosis and cell death types can vary. Apoptosis, chondroptosis, necrosis, and autophagic cell death are described in this review. The question of cell death causality in OA progression is also addressed, as well as the molecular pathways leading to cell death in response to the following inducers: Fas, Interleukin-1β (IL-1β), Tumor Necrosis factor-α (TNF-α), leptin, nitric oxide (NO) donors, and mechanical stresses. Furthermore, the protective role of autophagy in chondrocytes is highlighted, as well as its decline during OA progression, enhancing chondrocyte cell death; the transition being mainly controlled by HIF-1α/HIF-2α imbalance. Finally, we have considered whether interfering in chondrocyte apoptosis or promoting autophagy could constitute therapeutic strategies to impede OA progression.