Related Experiment Video
Updated: Jun 6, 2026
A Novel in vivo Gene Transfer Technique and in vitro Cell Based Assays for the Study of Bone Loss in Musculoskeletal Disorders
Published on: June 8, 2014
Anti-inflammatory effect of MAPK phosphatase-1 local gene transfer in inflammatory bone loss
1Department of Craniofacial Biology, Medical University of South Carolina, Charleston, SC 29425, USA.
Abstract:
Alveolar bone loss associated with periodontal diseases is the result of osteoclastogenesis induced by bacterial pathogens. The mitogen-activated protein kinase (MAPK) phosphatase 1 (MKP-1) is a critical negative regulator of immune response as a key phosphatase capable of dephosphorylating activated MAPKs. In this study, rat macrophages transduced with recombinant adenovirus (Ad.)MKP-1 specifically dephosphorylated activated MAPKs induced by lipopolysaccharide (LPS) compared with control cells. Bone marrow macrophages from MKP-1 knockout (KO) mice exhibited higher interleukin (IL)-6, IL-10, tumor necrosis factor (TNF)-α, and select chemokine compared with wild-type (WT) mice when stimulated by LPS. In addition, bone marrow cultures from MKP-1 KO mice exhibited significantly more osteoclastogenesis induced by LPS than when compared with WT mice. Importantly, MKP-1 gene transfer in bone marrow cells of MKP-1 KO mice significantly decreased IL-6, IL-10, TNF-α and chemokine levels, and formed fewer osteoclasts induced by LPS than compared with control group of cells. Furthermore, MKP-1 gene transfer in an experimental periodontal disease model attenuated bone resorption induced by LPS. Histological analysis confirmed that periodontal tissues transduced with Ad. MKP-1 exhibited less infiltrated inflammatory cells, less osteoclasts and less IL-6 than compared with rats of control groups. These studies indicate that MKP-1 is a key therapeutic target to control of inflammation-induced bone loss.
Insights
Mitogen-activated protein kinase phosphatase 1 (MKP-1) inhibits osteoclastogenesis and bone loss in periodontal disease. Gene transfer of MKP-1 reduces inflammation and bone resorption, highlighting its therapeutic potential.
Area of Science:
- Immunology
- Molecular Biology
- Periodontology
Background:
- Periodontal diseases cause alveolar bone loss via bacterial pathogen-induced osteoclastogenesis.
- Mitogen-activated protein kinase (MAPK) phosphatase 1 (MKP-1) negatively regulates immune responses by dephosphorylating activated MAPKs.
Purpose of the Study:
- To investigate the role of MKP-1 in regulating osteoclastogenesis and bone loss during periodontal disease.
- To evaluate the therapeutic potential of MKP-1 gene transfer in controlling inflammation-induced bone loss.
Main Methods:
- Utilized recombinant adenovirus (Ad.MKP-1) for gene transfer in rat macrophages and bone marrow cells.
- Compared bone marrow macrophages from MKP-1 knockout (KO) and wild-type (WT) mice stimulated with lipopolysaccharide (LPS).
- Assessed levels of inflammatory cytokines (IL-6, IL-10, TNF-α) and chemokine, osteoclastogenesis, and bone resorption in experimental periodontal disease models.
Main Results:
- Ad.MKP-1 transduced macrophages dephosphorylated activated MAPKs induced by LPS.
- MKP-1 KO macrophages showed increased IL-6, IL-10, TNF-α, and osteoclastogenesis upon LPS stimulation compared to WT.
- MKP-1 gene transfer in KO mice significantly reduced inflammatory markers, osteoclast formation, and bone resorption in vivo.
- Histological analysis showed reduced inflammatory cells, osteoclasts, and IL-6 in Ad.MKP-1 treated periodontal tissues.
Conclusions:
- MKP-1 acts as a crucial negative regulator of inflammatory responses and osteoclastogenesis.
- MKP-1 gene transfer demonstrates significant therapeutic potential for mitigating inflammation-induced alveolar bone loss in periodontal disease.
