RNA Sequencing Revealed Distinct Expression Profiles and Temporal Expression Dynamics in Murine Model of Foreign Body Reaction

ABSTRACT Foreign body reaction (FBR) is an inflammatory and fibrotic reaction to degradation‐resistant foreign materials characterised by the temporal cascade of cellular and molecular dynamics, which remains not fully elucidated. The aim of our study was to elucidate the temporal gene expression profiles of FBR. An FBR model was generated by implanting polycaprolactone into the abdominal subcutaneous layer of C57BL/6 mice. RNA sequencing was performed using established FBR tissues at various time points after implantation (FBR group; 2, 4, 8 and 12 weeks, n = 4 for each time points), and normal dorsal skin of mice as the control group ( n = 3). We identified distinct gene expression profiles between the control group and the FBR group. Extracellular matrix (ECM), immune, and epigenetics‐related genes were significantly enriched in the FBR group compared to normal skin. Within the FBR groups, expression profiles did not show definitive segregation across time points. We observed the highest expression of ECM‐related genes ( Adamts4 , Col9a3 , Col6a2 , and Furin ) and pathways in the 2‐week samples, followed by a gradual down‐regulation thereafter. In conclusion, our study elucidated distinct expression profiles of FBR in comparison to normal skin, as well as the temporal expression dynamics of FBR.