Increased Circulating CD14+ Monocytes in Patients with Psoriatic Arthritis Presenting Impaired Apoptosis Activity

Area of Science:

• Immunology
• Rheumatology
• Molecular Biology

Background:

• Psoriatic arthritis (PsA) is a chronic inflammatory condition impacting joints.
• Osteoclast activation drives the osteolytic effects observed in PsA joints.

Purpose of the Study:

• To investigate differential gene expression in peripheral CD14+ monocytes from PsA patients versus healthy controls.
• To identify molecular mechanisms underlying monocyte dysfunction in PsA.

Main Methods:

• Isolation of peripheral CD14+ monocytes from PsA patients (n=15) and healthy controls (n=15).
• Flow cytometry for apoptosis assessment (Annexin V).
• Microarray analysis for gene expression profiling (GEO accession: GSE261765) and PCR validation.

Main Results:

• PsA patients exhibited a higher count of peripheral CD14+ monocytes compared to HCs.
• Apoptosis signaling pathways were significantly impaired in CD14+ monocytes from PsA patients.
• Relative expression of cathepsin L was significantly lower in PsA monocytes.

Conclusions:

• Increased peripheral CD14+ monocyte numbers and impaired apoptosis in PsA patients.
• This monocyte dysfunction may promote macrophage maturation and osteoclast activation.
• Resistance to apoptosis in CD14+ monocytes could contribute to active joint inflammation in PsA.