Lang A, Neuhaus J, Pfeiffenberger M, Schröder E, Ponomarev I, Weber Y, Gaber T, Schmidt MFG. Optimization of a nonviral transfection system to evaluate Cox-2 controlled interleukin-4 expression for osteoarthritis gene therapy in vitro.
J Gene Med 2015;
16:352-63. [PMID:
25382123 DOI:
10.1002/jgm.2812]
[Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 06/15/2014] [Accepted: 11/03/2014] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND
Gene therapy appears to have the potential for achieving a long-term remedy for osteoarthritis (OA). However, there is a risk of adverse reactions, especially when using cytomegalovirus-controlled expression. To provide a safe application, we focused on the expression of therapeutic cytokines [e.g. interleukin (IL)-4] in a disease-responsive manner by use of the previously cloned Cox-2 promoter as 'genetic switch'. In the present study, we report the functionality of a controlled gene therapeutic system in an equine osteoarthritic cell model.
METHODS
Different nonviral transfection reagents were tested for their efficiency on equine chondrocytes stimulated with equine IL-1β or lipopolysaccharide to create an inflammatory environment. To optimize the transfection, we successfully redesigned the vector by excluding the internal ribosomal entry site (IRES). The functionality of our Cox-2 promoter construct with respect to expressing IL-4 was proven at the mRNA and protein levels and the anti-inflammatory potential of IL-4 was confirmed by analyzing the expression of IL-1β, IL-6, IL-8, matrix metalloproteinase (MMP)-1, MMP-3 and tumor necrosis factor (TNF)-α using a quantitative polymerase chain reaction.
RESULTS
Nonviral transfection reagents yielded transfection rates from 21% to 44% with control vectors with and without IRES, respectively. Stimulation of equine chondrocytes resulted in a 20-fold increase of mRNA expression of IL-1β. Such exogenous stimulation of chondrocytes transfected with pNCox2-IL4 led to an increase of IL-4 mRNA expression, whereas expression of inflammatory mediators decreased. The timely link between these events confirms the anti-inflammatory potential of synthesized IL-4.
CONCLUSIONS
We consider that this approach has significant potential for translation into a useful anti-inflammation therapy. Molecular tools such as the described therapeutic plasmid pave the way for a local-controlled, self-limiting gene therapy.
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