DUSP4 alleviates LPS-induced chondrocyte injury in knee osteoarthritis via the MAPK signaling pathway

Area of Science:

• Biomedical research
• Cell biology
• Molecular mechanisms of disease

Background:

• Knee osteoarthritis (KOA) involves complex cartilage damage pathogenesis.
• Dual specificity protein phosphatase 4 (DUSP4) expression is reduced in osteoarthritis (OA).
• The precise function and mechanism of DUSP4 in OA remain unclear.

Purpose of the Study:

• To investigate the role and mechanism of DUSP4 in knee osteoarthritis.
• To determine if DUSP4 affects chondrocyte viability, oxidative stress, inflammation, and apoptosis.
• To elucidate the involvement of the MAPK signaling pathway in DUSP4's function in OA.

Main Methods:

• Established an OA cell injury model using ATDC5 cells treated with lipopolysaccharide (LPS).
• Quantified DUSP4 expression using reverse transcription-quantitative PCR and western blot.
• Assessed cell viability, oxidative stress, inflammation, and apoptosis via Cell Counting Kit-8, ELISA, TUNEL, and western blotting assays.
• Investigated the MAPK pathway's role using a specific agonist (PMA).

Main Results:

• DUSP4 expression was significantly decreased in OA chondrocytes.
• Overexpression of DUSP4 inhibited LPS-induced chondrocyte injury.
• DUSP4 overexpression suppressed the MAPK signaling pathway, reducing oxidative stress, inflammation, and apoptosis.
• MAPK pathway activation reversed the protective effects of DUSP4.

Conclusions:

• DUSP4 plays a protective role in knee osteoarthritis.
• DUSP4 alleviates LPS-induced chondrocyte injury in KOA.
• The protective mechanism involves the inhibition of the MAPK signaling pathway.