Long-term repair of porcine articular cartilage using cryopreservable, clinically compatible human embryonic stem cell-derived chondrocytes
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ABSTRACT: Osteoarthritis (OA) impacts hundreds of millions of people worldwide, with those affected incurring significant physical and financial burdens. Injury to the articular surface is a major contributing risk factor for the development of OA. Current cartilage repair strategies are moderately effective at reducing pain but often replace damaged tissue with biomechanically inferior fibrocartilage. Here we describe the development, transcriptomic ontogenetic characterization and quality assessment at the single cell level, as well as the scaled manufacturing of an allogeneic pluripotent stem cell-derived articular chondrocyte formulation that exhibits long-term functional repair of porcine articular cartilage. These results define a new potential clinical paradigm for articular cartilage repair and mitigation of the associated risk of OA.
Project description:Full thickness articular cartilage lesions with penetration into the subchondral bone fill with fibrocartilage-like repair tissue. However, the repair tissue has compromised structural and biomechanical properties relative to normal articular cartilage. The objective of this study was to evaluate transcriptome differences between normal articular cartilage and repair tissue. Bilateral one-cm2 full-thickness lesions were made in the articular surface of the distal femurs of four adult horses followed by subchondral microfracture. Four months postoperatively, repair tissue from the lesion site and grossly normal articular cartilage from each stifle were collected. Total RNA was isolated from tissue samples, linearly amplified, and applied to a 9367-probeset equine-specific cDNA microarray. Eight paired comparisons matched by limb and horse were made with a dye-swap experimental design. Comparisons were validated by histological analysis and quantitative real-time polymerase chain reaction (qPCR). Statistical analysis revealed 3,327 (35.2%) differentially expressed probesets. Biomarkers typically associated with normal articular cartilage and fibrocartilage repair tissue corroborate earlier studies. Other changes in gene expression previously unassociated with cartilage repair were also revealed and validated by qPCR. The magnitude of divergence in transcriptional profiles between normal chondrocytes and the cells that populate repair tissue reveal substantial functional differences between these two cell populations. At the four-month postoperative time point, the relative deficiency within repair tissue of transcripts from genes which typically define articular cartilage indicate that while cells occupying the lesion might be of mesenchymal origin, they have not recapitulated differentiation to the chondrogenic phenotype of normal articular chondrocytes.
Project description:As the most common degenerative joint disease, osteoarthritis (OA) contributes significantly to pain and disability during aging. Several genes of interest involved in articular cartilage damage in OA have been identified. However, the direct causes of OA are poorly understood. Evaluating the public human RNA-seq dataset showed that Cbfβ, (subunit of a heterodimeric Cbfβ/Runx1,Runx2, or Runx3 complex) expression is decreased in the cartilage of patients with OA. Here, we found that the chondrocyte-specific deletion of Cbfβ in tamoxifen-induced Cbfβf/fCol2α1-CreERT mice caused a spontaneous OA phenotype, worn articular cartilage, increased inflammation, and osteophytes. RNA-sequencing analysis showed that Cbfβ deficiency in articular cartilage resulted in reduced cartilage regeneration, increased canonical Wnt signaling and inflammatory response, and decreased Hippo/YAP signaling and TGF-β signaling. Immunostaining and western blot validated these RNA-seq analysis results. ACLT surgery-induced OA decreased Cbfβ and Yap expression and increased active β-catenin expression in articular cartilage, while local AAV-mediated Cbfβ overexpression promoted Yap expression and diminished active β-catenin expression in OA lesions. Remarkably, AAV-mediated Cbfβ overexpression in knee joints of mice with OA showed the significant protective effect of Cbfβ on articular cartilage in the ACLT OA mouse model. Overall, this study, using loss-of-function and gain-of-function approaches, uncovered that low expression of Cbfβ may be the cause of OA. Moreover, Local admission of Cbfβ may rescue and protect OA through decreasing Wnt/β-catenin signaling, and increasing Hippo/Yap signaling and TGFβ/Smad2/3 signaling in OA articular cartilage, indicating that local Cbfβ overexpression could be an effective strategy for treatment of OA. Using unbiased genome-wide RNA-seq data from Cbfβf/f;Col2α1-Cre hip joint articular cartilage and Cbfβf/f;Aggrecan-cre knee joint articular cartilage and their controls, we examined Cbfβ-mediated transcriptional targets for articular cartilage regeneration in OA.
Project description:Osteoarthritis (OA) is a degenerative joint disease that involves destruction of articular cartilage and eventually leads to disability. Mesenchymal stem cells (MSCs) reside in healthy and diseased cartilage, and through their chondrogenic potential may provide a strategy for cartilage repair. To this end, we performed an image-based, high throughput screen and identified the small molecule, kartogenin, that promotes selective MSC differentiation into chondrocytes (EC50=100nM), shows chondroprotective effects in vitro, and is efficacious in two OA animal models. Kartogenin binds filamin A and induces chondrogenesis by regulating the CBFbeta-RUNX1 transcriptional program. This work provides new insights into the control of chondrogenesis that may ultimately lead to an effective stem-cell based therapy for osteoarthritis. one compound, three doses, two time points, a vehicle control
Project description:Osteoarthritis (OA) is characterised by an irreversible degeneration of articular cartilage. Here we show that the BMP-antagonist Gremlin 1 (Grem1) marks a bipotent chondrogenic and osteogenic progenitor cell population within the articular surface. Notably, these progenitors are depleted by injury-induced OA and increasing age. OA is also caused by ablation of Grem1 cells in mice. Transcriptomic and functional analysis in mice found that articular surface Grem1-lineage cells are dependent on Foxo1 and ablation of Foxo1 in Grem1-lineage cells caused OA. FGFR3 signalling was confirmed as a promising therapeutic pathway by administration of pathway activator, FGF18, resulting in Grem1-lineage chondrocyte progenitor cell proliferation, increased cartilage thickness and reduced OA. These findings suggest that OA, in part, is caused by mechanical, developmental or age-related attrition of Grem1 expressing articular cartilage progenitor cells. These cells, and the FGFR3 signalling pathway that sustains them, may be effective future targets for biological management of OA.
Project description:Background: Meniscus tears are the most common injury in the knee and are associated with an increased risk of osteoarthritis (OA). The molecular profile of knees with meniscus tears is not well-studied. Therefore, to advance our understanding of the early response of the knee to injury, we compared the gene expression profile of meniscus and articular cartilage within the same knees following meniscus injury. Hypothesis/Purpose: To identify differences between the molecular signatures of meniscus and articular cartilage from knees with intact articular cartilage undergoing arthroscopic partial meniscectomy. Study Design: Descriptive laboratory study Methods: Patients (n=12) with a known isolated medial meniscus tear without any knee chondrosis or radiographic OA were consented prior to surgery. During arthroscopic partial meniscectomy, a sample of their injured meniscus and a sample of their articular cartilage off the medial femoral condyle were procured. The transcriptome signatures, as measured through Affymetrix microarray, were compared between the two tissues and underlying biological processes were explored computationally. Results: 3566 gene transcripts were differentially expressed between meniscus and articular cartilage. Gene transcripts down-regulated in articular cartilage were associated with extracellular matrix organization, wound healing, cell adhesion, and chemotaxis. Gene transcripts up-regulated in articular cartilage were associated with blood vessels morphogenesis and angiogenesis. Examples of individual genes with significant differences in expression between the two tissues include IBSP (23.76 fold; P < 0.001), upregulated in meniscus, and TREM1 (3.23 fold; P = 0.006), upregulated in meniscus. Conclusion: The meniscus and articular cartilage have distinct gene expression profiles in knees with meniscus tears and intact articular cartilage. Total RNA obtained from injured meniscus and normal articular cartilage from patients undergoing partial meniscectomy.
Project description:Previous studies have demonstrated relative deficiencies of repair tissue within articular lesions when compared to articular cartilage. While cells occupying the lesions might be of mesenchymal origin, they do not recapitulate differentiation to the chondrogenic phenotype of normal articular chondrocytes. Nevertheless, attributes of repair tissue appear similar to chondrocytes and their precursors at various other different states. We hypothesized that analyses of gene expression profiles for these other cell phenotypes would elucidate the identity of repair tissue cells. Total RNA was isolated from repair tissue samples, neonatal articular cartilage, primary articular chondrocytes maintained in monolayer culture and passaged weekly over 28 days, and bone marrow stromal cells expanded to 80% confluence in monolayer culture. Total RNA was linearly amplified and applied to a 9413-probe set equine-specific cDNA microarray. Four repair tissue samples were compared with a dye-swap experimental design to four samples from each of the three other cell populations for a total of twelve comparisons, or twenty-four slides. Differential expression of genes of interest was validated by real-time quantitative polymerase chain reaction. Statistical analysis revealed that a total of 934 (9.9%), 1839 (19.5%), and 940 (10.0%) probe sets were differentially expressed for the bone marrow stromal cells versus repair tissue, de-differentiated chondrocytes versus repair tissue, and neonatal articular chondrocytes versus repair tissue comparisons, respectively. Transcriptional and translational machinery gene ontological categories were over-represented in transcripts demonstrating stable expression amongst the three comparisons. Biomarkers typically associated with normal articular cartilage and fibrocartilage repair tissue comprised much of the genes with the greatest levels of differential expression amongst the three comparisons. Overall, the profiles indicated that repair cells were more chondrogenic than bone marrow stromal cells and de-differentiated chondrocytes. However, transcript levels of key biomarkers and growth factors for repair tissue cells four months post-operatively fell far short of those of neonatal articular chondrocytes destined to undergo normal cartilage maturation.
Project description:Osteoarthritis (OA) is a prevalent degenerative disease, which involves progressive and irreversible destruction of cartilage matrix. Despite efforts to reconstruct cartilage matrix in osteoarthritic joints, it has been a difficult task as adult cartilage exhibits marginal repair capacity. Here we report the identification of tankyrase as a regulator of the cartilage anabolism axis based on systems-level factor analysis of mouse reference populations. Tankyrase inhibition drives the expression of a cartilage-signature matrisome and elicits a transcriptomic pattern that is inversely correlated with OA progression. Furthermore, tankyrase inhibitors ameliorate surgically-induced OA in mice, and stem cell transplantation coupled with tankyrase knockdown results in superior regeneration of cartilage lesions. Mechanistically, the pro-regenerative features of tankyrase inhibition are mainly triggered by uncoupling SOX9 from a poly(ADP-ribosyl)ation (PARylation)-dependent protein degradation pathway. Our findings provide insights into the development of future OA therapies aimed at reconstruction of articular cartilage.
Project description:Genome wide gene expression was determined in paired samples of OA affected and preserved cartilage of the same joint using microarray analysis for 33 patients of the RAAK-study. Among the 1717 genes that were significantly different expressed between OA affected and preserved cartilage we found significant enrichment for genes involved in skeletal development (e.g. TNFRSF11B and FRZB). Also several inflammatory genes such as CD55, PTGES and TNFAIP6, previously identified in within-joint analyses as well as in analyses comparing preserved cartilage from OA affected joints versus healthy cartilage were among the top genes. A notable new gene was NGF, highly up-regulated in OA cartilage. To identify gene expression profiles associated with OA processes in articular cartilage and determine pathways responsive to the disease process gene expression profiles of paired preserved and OA affected cartilage samples of the same joint were determined.
Project description:Proteolytic destruction of articular cartilage is a major pathogenic mechanism in osteoarthritis (OA), but was not previously investigated on a proteome-wide scale. We sought to define the human knee OA cartilage degradome.
Project description:Articular cartilage is deprived of blood vessels and nerves, and the only cells residing in this tissue are chondrocytes. The molecular properties of the articular cartilage and the architecture of the extracellular matrix demonstrate a complex structure that differentiates on the depth of tissue. Osteoarthritis (OA) is a degenerative joint disease, the most common form of arthritis, affecting the whole joint. It is associated with ageing and affects the joints that have been continually stressed throughout life including the knees, hips, fingers, and lower spine region. OA is a multifactorial condition of joint characterised by articular cartilage loss, subchondral bone sclerosis, and inflammation leading to progressive joint degradation, structural alterations, loss of mobility and pain. Articular cartilage biology is well studied with a focus on musculoskeletal diseases and cartilage development. However, there are relatively few studies focusing on zonal changes in the cartilage during osteoarthritis.