Chemically modified ribozyme targeting TNF-alpha mRNA regulates TNF-alpha and IL-6 synthesis in synovial fibroblasts of patients with rheumatoid arthritis

Nucleic Acid Engineering: RNA Following the Trail of DNA

The self-assembly feature of the naturally occurring biopolymer, DNA, has fascinated researchers in the fields of materials science and bioengineering. With the improved understanding of the chemical and structural nature of DNA, DNA-based constructs have been designed and fabricated from two-dimensional arbitrary shapes to reconfigurable three-dimensional nanodevices. Although DNA has been used successfully as a building block in a finely organized and controlled manner, its applications need to be explored. Hence, with the myriad of biological functions, RNA has recently attracted considerable attention to further the application of nucleic acid-based structures. This Review categorizes different approaches of engineering nucleic acid-based structures and introduces the concepts, principles, and applications of each technique, focusing on how DNA engineering is applied as a guide to RNA engineering.

Antisense makes sense in engineered regenerative medicine

The use of antisense strategies such as ribozymes, oligodeoxynucleotides (ODNs) and small interfering RNA (siRNA) in gene therapy, in conjunction with the use of stem cells and tissue engineering, has opened up possibilities in curing degenerative diseases and injuries to non-regenerating organs and tissues. With their unique ability to down-regulate or silence gene expression, antisense oligonucleotides are uniquely suited in turning down the production of pathogenic or undesirable proteins and cytokines. Here, we review the antisense strategies and their applications in regenerative medicine with a focus on their efficacies in promoting cell viability, regulating cell functionalities as well as shaping an optimal microenvironment for therapeutic purposes.

Gene targeting by ribozyme against TNF-alpha mRNA inhibits autoimmune arthritis

Ribozymes are catalytic RNA that bind and cleave specific regions of target RNA. Therefore, protein synthesis by the target RNA may be specifically inhibited by ribozymes. In this study, we have investigated if ribozymes possess therapeutic activity on inflammatory processes in vivo, as judged from effects on an arthritis model. A hammerhead ribozyme against TNF-alpha was designed and its catalytic activity in vitro was verified. The ribozyme was employed in vivo without any delivery system, as the plasmid-based ribozyme was taken up adequately by various tissues in mice by intravenous injection. The ability of the ribozyme to regulate the development of collagen-induced arthritis (CIA), a model largely dependent on TNF-alpha, was investigated. Systemic administration of the ribozyme to mice immunized with collagen type II in CFA significantly reduced the development of CIA. No effect was observed with a catalytically inactive variant of the ribozyme. Furthermore, the ribozyme efficiently blocked cartilage and bone destruction in the joints and ameliorated established CIA. These data demonstrate for the first time that gene targeting by a ribozyme to inactivate TNF-alpha in vivo is highly efficient in suppressing autoimmune arthritis, thus providing proof of concept that it may be used as therapeutic tool for TNF-alpha-dependent chronic inflammatory disorders.

Anti-inflammatory effect of linear polarized infrared irradiation on interleukin-1β-induced chemokine production in MH7A rheumatoid synovial cells

We examined the anti-inflammatory effect of infrared linear polarized light irradiation on the MH7A rheumatoid fibroblast-like synoviocytes (FLS) stimulated with the proinflammatory cytokine interleukin (IL)-1beta. Expression of messenger ribonucleic acids (mRNAs) encoding IL-8, RANTES (regulated upon activation, normal T cell expressed and secreted), growth-related gene alpha (GROalpha), and macrophage inflammatory protein-1alpha (MIP1alpha) was measured using real-time reverse transcription polymerase chain reaction, and the secreted proteins were measured in the conditioned media using enzyme-linked immunosorbent assays. We found that irradiation with linear polarized infrared light suppressed IL-1beta-induced expression of IL-8 mRNA and, correspondingly, the synthesis and release of IL-8 protein in MH7A cells. This anti-inflammatory effect was equivalent to that obtained with the glucocorticoid dexamethasone. Likewise, irradiation suppressed the IL-1beta-induced expression of RANTES and GROalpha mRNA. These results suggest that the irradiation of the areas around the articular surfaces of joints affected by rheumatoid arthritis (RA) using linear polarized light may represent a useful new approach to treatment.

Gene transfer as a future therapy for rheumatoid arthritis

Inhibiting key pathogenic processes within the rheumatoid synovium is a most attractive goal to achieve, and the number of potential intra- and extracellular pathways operative in rheumatoid arthritis (RA) that could be used for a gene therapy strategy is increasing continuously. Gene transfer or gene therapy might also be one of the approaches to solve the problem of long-term expression of therapeutic genes, in order to replace the frequent application of recombinant proteins, in the future. However, at present, gene therapy has not reached a realistic clinical stage, which is mainly due to severe side effects in humans, the complexity of RA pathophysiology and the current state of available gene transfer techniques. On the other hand, novel gene delivery systems are not restricted to vectors or certain types of cells, as mobile cells including macrophages, dendritic cells, lymphocytes and multipotent stem cells can also be used as smart gene transfer vehicles. Moreover, the observation in animal models that application of viral vectors into a joint can exert additional therapeutic effects in nearby joints might also facilitate the transfer from animal to human gene therapy. Future strategies will also examine the potential of novel long-term expression vectors such as lentiviruses and cytomegalovirus (CMV)-based viruses as a basis for future clinical trials in RA.

Ribozymes: recent advances in the development of RNA tools

The discovery 20 years ago that some RNA molecules, called ribozymes, are able to catalyze chemical reactions was a breakthrough in biology. Over the last two decades numerous natural RNA motifs endowed with catalytic activity have been described. They all fit within a few well-defined types that respond to a specific RNA structure. The prototype catalytic domain of each one has been engineered to generate trans-acting ribozymes that catalyze the site-specific cleavage of other RNA molecules. On the 20th anniversary of ribozyme discovery we briefly summarize the main features of the different natural catalytic RNAs. We also describe progress towards developing strategies to ensure an efficient ribozyme-based technology, dedicating special attention to the ones aimed to achieve a new generation of therapeutic agents.