The embryonic origins of site-specific arthritis.

ABSTRACT: The cellular basis for site-specific inflammation remains unclear. In human fingers, proximal interphalangeal (PIP) joints are preferentially affected by inflammatory arthritis, whereas distal interphalangeal joints are spared, providing a model to investigate the predilection of inflammation to distinct sites. Here we combine single-cell RNA sequencing, imaging and X-ray tomography to examine cellular composition, spatial organization and structure of finger joints during fetal development. PIP joints had a larger synovial volume and were enriched for PI16⁺ 'universal' fibroblasts. These cells were located in perivascular regions and at developing tendon-ligament interfaces. PI16⁺ fibroblasts exhibited both a shared inflammatory and cell-type-specific response to cyt

SUBMITTER: Davidson S 

PROVIDER: S-EPMC13310765 | biostudies-literature | 2026 Jul

REPOSITORIES: biostudies-literature