Psoriatic Arthritis Skin Demonstrates Upregulated Chemokines

According to a study published in Arthritis Research & Therapy, lesional psoriatic arthritis (PsA) skin shows upregulated chemokines and their receptors compared with uninvolved PsA skin.

Researchers aimed to compare the transcriptome of PsA skin with healthy control (HC) skin by evaluating atypical chemokine receptor 2 (ACKR2) expression in PsA skin. They conducted full-thickness skin biopsies from HC skin and sequenced lesional and uninvolved skin from participants with PsA on NovaSeq 6000. These findings were validated using quantitative polymerase chain reaction (qPCR) and RNAscope.

Results showed that PsA uninvolved skin shared a similarity with HC skin, whereas lesional PsA skin was enriched in epidermal and inflammatory genes. Additionally, lesional PsA skin was enriched in chemokine-mediated signaling pathways compared with uninvolved skin, which was not. Also, ACKR2 was upregulated in lesional PsA skin compared with HC skin, which had an unchanged expression. Researchers confirmed the expression of ACKR2 by utilizing qPCR, and the RNAscope showcased a strong expression of ACKR2 in the suprabasal layer of the epidermis in PsA lesions.

“In contrast to previous psoriasis studies, ACKR2 was not upregulated in uninvolved PsA skin,” the authors stated. “Further understanding of the chemokine system in PsA may help to explain why inflammation spreads from the skin to the joints in some people with psoriasis,” they concluded.

Reference
Johnsson H, Cole J, Siebert S, McInnes IB, Graham G. Cutaneous lesions in psoriatic arthritis are enriched in chemokine transcriptomic pathways. Arthritis Res Ther. Published online May 2, 2023. doi:10.1186/s13075-023-03034-6