Anti-apoptotic Bcl-2 gene transfection of human articular chondrocytes protects against nitric oxide-induced apoptosis

Abstract

We stably transfected early passage chondrocytes with an anti-apoptotic Bcl-2 gene in vitro using a retrovirus vector. Samples of articular cartilage were obtained from 11 patients with a mean age of 69 years (61 to 75) who were undergoing total knee replacement for osteoarthritis. The Bcl-2-gene-transfected chondrocytes were compared with non-transfected and lac-Z-gene-transfected chondrocytes, both of which were used as controls. All three groups of cultured chondrocytes were incubated with nitric oxide (NO) for ten days. Using the Trypan Blue exclusion assay, an enzyme-linked immunosorbent assay and flow cytometric analysis, we found that the number of apoptotic chondrocytes was significantly higher in the non-transfected and lac-Z-transfected groups than in the Bcl-2-transfected group (p < 0.05). The Bcl-2-transfected chondrocytes were protected from NO-induced impairment of proteoglycan synthesis. We conclude that NO-induced chondrocyte death involves a mechanism which appears to be subject to regulation by an anti-apoptotic Bcl-2 gene. Therefore, Bcl-2 gene therapy may prove to be of therapeutic value in protecting human articular chondrocytes.

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

“…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. Growth, transcription and enzymatic factors are potent candidates to achieve these goals because of their anabolic or mitogenic properties such as fibroblast growth factor 2 (FGF-2) (20,21), bone morphogenetic proteins 2 and 4 (BMP-2 and BMP-4) (22,23), transforming growth factor β (TGF-β) (22,24,25), transcription factor sex-determining region Y-type high mobility group box 9 (SOX9) (20,26,27), glucuronosyltransferase-I (28), bcl-2 (29) and telomerase (30). A critical agent that may have the strongest value to readjust the disturbed homeostasis in OA cartilage is insulinlike growth factor (IGF)-I, since it has the ability to influence concomitantly metabolic and proliferative processes, affording protection against extracellular matrix degradation in horse and rabbit articular cartilage explant cultures experimentally treated with proinflammatory cytokines (13,14,22).…”

“…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).…”

Induction of CD56 and TCR-Independent Activation of T Cells with Aging

“…p16 is a direct inhibitor of mitosis that leads to irreversible arrest of cell division (35), whereas p53 is an indirect mitotic inhibitor through signaling of p21 expression (36). A role of Bcl2 in senescence could be inferred from findings about correlation between high levels of its expression and resistance to programmed cell death of CD28 null T cells (41) and other senescent somatic cells (37,50,51). Fig.…”

Melanocortin peptides protect chondrocytes from mechanically induced cartilage injury

“…Additionally, OA is featured by reduced cellularity [21,[23][24][25][26][27][28][29], a fact that is thought to contribute to the inability of the remaining chondrocytes to maintain normal matrix synthesis, thereby contributing to cartilage degradation [30].…”