Background/Purpose:

Excessive production of reactive oxygen species (ROS) of the chondrocyte plays an important role of cartilage degradation, inflammation, and increased chondrocyte death in the development and progression of osteoarthritis (OA). Recently, many studies have demonstrated that the transduction of a therapeutic protein using protein transduction domain (PTD), which targets the lipid bilayer directly can be utilized for therapeutic applications. GLRX (Glutaredoxins) are endogenous antioxidant systems and key players in the balance of cellular redox homeostasis. In this study we sought to investigate whether PEP-1-GLRX-1, a fusion protein of GLRX-1 with PEP-1 peptide, one of protein transduction domains, could suppress catabolic responses in primary human chondrocytes and carrageenan-induced paw edema mouse model.

Methods:

Human articular chondrocytes were enzymatically isolated from articular cartilage and cultured in monolayer. The transduction efficiency of PEP-1-GLRX1 into articular chondrocytes was measured by Western blot and immunochemistry analysis. The effect of PEP-1-GLRX1 on MMP expression and catabolic factor expressions in interleukin-1β (IL-1β)- and lipopolysaccharide (LPS)-treated chondrocytes were analyzed by real-time quantitative reverse transcription-polymerase chain reaction and Western blot analysis. The effect of PEP-1-GLRX1 on mitogen activated protein kinase (MAPK) and NF-κB signaling pathway were analyzed by Western blot analysis. The inhibitory effect of PEP-1-GLRX-1 on MMP13 production was measured in carrageenan-induced edema mouse model.

Results:

PEP-1- Efficient penetration of GLRX-1 into human and mouse cartilage was demonstrated by western blot and immunochemistry analysis. PEP-1-GLRX-1 in interleukin-1β (IL-1β)- and lipopolysaccharide (LPS)-treated chondrocytes significantly suppressed the expressions of matrix metalloproteinase (MMP)-13 and inducible NO synthase (iNOS), at both mRNA and protein levels compared with GLRX-1. In addition, PEP-1-GLRX-1 decreased IL-1β- and LPS-induced activation of mitogen activated protein kinase (MAPK) and NF-κB. In a mouse model of carrageenan-induced paw edema, PEP-1-GLRX-1 significantly suppressed carrageenan-induced MMP-13 production as well as paw edema.

Conclusion:

Therefore, these results showed that PEP-1-GLRX-1 can be efficiently transduced in vitro and in vivo and down-regulate catabolic responses in chondrocytes and in arthritis animal model through inhibiting activation of MAPK and NF-κB. PEP-1-GLRX-1 has a potential to reduce catabolic responses in chondrocytes and cartilage.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/effect-of-pep-1-glrx-1-on-catabolic-gene-expression-in-human-articular-chondrocytes-and-in-mouse-carrageenan-induced-paw-edema-model/