Gene transfer with HSP 70 in rat chondrocytes confers cytoprotection in vitro and during experimental osteoarthritis

Abstract

Osteoarthritis is characterized by a gradual degradation of extracellular matrix, resulting from an excess of chondrocyte cell death, mainly due to an increase in apoptotis. Recent studies have revealed the essential role of HSP70 in protecting cells from stressful stimuli. Therefore, overexpressing HSP70 in chondrocytes could represent a good strategy to prevent extracellular matrix destruction. To this end, we have developed a vector carrying HSP70/GFP, and transduced chondrocytes were thus more resistant to cell death induced by mono-iodoacetate (MIA). To overcome the barrier-effect of matrix, we investigated the efficacy of plasmid delivery by electroporation (EP) in rat patellar cartilage. Two days after EP, 50% of patellar chondrocytes were HSP/GFP+. After 3 months, long-term expression of transgene was only depicted in the deep layer (20-30% positive cells). HSP70 overexpression inhibited the natural endochondral ossification in the deep layer, thus leading to a lesser decrease in chondrocyte distribution. Moreover, overexpression of HSP70, after a preventive EP transfer in rat patella, was sufficient to decrease the severity of osteoarthritis-induced lesions, as demonstrated histologically and biochemically. In conclusion, intracellular overexpression of HSP70, through EP delivery, could protect chondrocytes from cellular injuries and thus might be a novel chondroprotective modality in rat OA.

Increased expression of matrilin‐3 not only in osteoarthritic articular cartilage but also in cartilage‐forming tumors, and down‐regulation of SOX9 via epidermal growth factor domain 1–dependent signaling

“…PHCs were obtained from the healthiest pieces of articular cartilage, procured in the context of prosthesis replacement as described previously (19). The PHCs were inoculated at 10 6 cells per 75-cm 2 flask in 15 ml culture medium (Dulbecco's modified Eagle's medium [DMEM]/F-12, 10% fetal calf serum [FCS]), and grown to confluence.…”

Benefits of Recombinant Adeno-Associated Virus (rAAV)-Mediated Insulinlike Growth Factor I (IGF-I) Overexpression for the Long-Term Reconstruction of Human Osteoarthritic Cartilage by Modulation of the IGF-I Axis

“…Current approaches that aim at re-equilibrating the metabolic balance in OA cartilage are on the basis of the transfer of sequences coding for agents that either counteract the processes of matrix degradation or enhance the synthesis of matrix components. Protective effects against cartilage breakdown have been documented in experimental models of OA using sequences coding for inhibitors of inflammatory pathways (an IL-1 receptor antagonist [IL-1Ra], soluble TNF receptor [sTNFR], tissue inhibitor of metalloproteinases [TIMP-1]) (6)(7)(8)(9)(10)(11)(12)(13)(14) or factors such as IL-10 (12), heat shock protein 70 (15), glutamine:fructose-6-phosphate amidotransferase (16), thrombospontin-1 (17), kallistatin (18) and inhibitors of nuclear factor κB (19). Even though application of these stimuli was capable of containing cartilage degradation, it was not sufficient to compensate for the loss of matrix elements and cells and to reestablish an original cartilage surface.…”

“…In contrast with vectors derived from adenoviruses (6,10,13,14,(16)(17)(18)(19)21,22,25) and retroviruses (7,11,12,23,26,30) or with nonviral compounds (8,15,28,29), systems based on the replication-defective, nonpathogenic human adeno-associated virus (AAV) may provide better tools for OA, since recombinant AAV (rAAV) can deliver genes in nondividing cells such as chondrocytes both in vitro and in situ in their dense extracellular matrix at high efficiencies and for extended periods of time (20,24,27,31). Also, removal of the viral protein coding sequences in rAAV make them less immunogenic than adenoviral vectors characterized by shortterm transgene expression levels (32).…”

Restoration of the extracellular matrix in human osteoarthritic articular cartilage by overexpression of the transcription factor SOX9

“…Protective effects of an IL-1 receptor antagonist (IL-1Ra) sequence against IL-1-induced cartilage breakdown have been documented in experimental models ex vivo (5,6) and in vivo (7,8). The transfer of the gene for a heat-shock protein (Hsp70) was also shown to afford protection against cellular injuries in chondrocytes (9). Alternatively, the delivery of sequences encoding for growth and enzymatic factors can potentially stimulate cartilage anabolism in vitro and in situ, such as insulinlike growth factor 1 (IGF-1) (10), fibroblast growth factor 2 (FGF-2) (11), bone morphogenetic protein 7 (BMP-7) (12), transforming growth factor ␤ (TGF␤) (13), and glucuronosyltransferase I (14).…”