Assessment of the Role of Telocyte Zbtb16 in Lymphatic Drainage using Efhd1-CreERT2 x Zbtb16 ^flox/flox Mice

Lymphatic function is critical for maintaining fluid homeostasis and immune surveillance in synovial tissues, and its dysfunction is implicated in the progression of rheumatoid arthritis and osteoarthritis. Zbtb16, a transcription factor involved in cellular differentiation that is downregulated in mice with inflammatory arthritis and lymphatic defects, has been linked to skeletal development and immune regulation, but its direct role in lymphatic function remains unexplored. To investigate this, we generated Zbtb16 ^fl/fl mice for conditional-inducible loss-of-function experiments. Initial validation studies demonstrated that CMV-Cre x Zbtb16 ^fl/fl mice display the same skeletal phenotypes as previously reported Zbtb16 ^-/- global knockout mice. To achieve telocyte-specific deletion, Efhd1-CreERT2 x Zbtb16 ^fl/fl mice were treated with tamoxifen, and successful recombination was verified by PCR analysis of genomic DNA from popliteal lymphatic vessel tissue. Functional assessment using NIR-ICG imaging demonstrated that Zbtb16 deletion in telocytes partially impaired lymphatic clearance, suggesting a role in maintaining lymphatic function during homeostasis. These findings demonstrate the utility of Zbtb16 ^fl/fl mice for their intended purpose and support future studies on the role of Zbtb16 within the synovial lymphatic system.