PRS PSRC Podium Proofs 2016
Mingu Hong, BA,* Sara Yang, BA,* Eunson Jung, MA,* Won Jung, BA,* Young Jin Seoung, BA,* Eunkyung Park, MA,* Athanasios Bramos, MD,* Kyu Kim, PhD,* Sunju Lee, PhD,* George Daghlian, BA,* Jung In Seo, BA,* Inho Choi, PhD,* In-Seon Choi, PhD,† Chester Koh, MD,† Agnieszka Kobielak, PhD,* Qi-Long Ying, PhD,* Maxwell Johnson, MS,* Daniel Gardner, MS,* Alex K. Wong, MD,* Dongwon Choi, PhD,* Young-Kwon Hong, PhD*
From the *Keck School of Medicine of USC, Los Angeles, Calif.; and †Baylor College of Medicine, Houston, Tex.
PURPOSE: Lymphatic reporter mouse lines are important tools in the study of the lymphatic vascular system. Unfortunately, many are limited by their reliance on promoters that fail to recapitulate endogenous gene expression patterns. In this study, we aimed to evaluate the reporter expression pattern of the novel lymphatic reporter line Prox1-tdTomato and to assess its value in studying lymphangiogenesis.
METHODS: Reporter expression pattern was evaluated using fluorescent imaging in embryos and adult mouse tissue. Lymphangiogenesis was evaluated using unilateral axillary lymphadenectomy, axillary lymph node transplantation, and a mouse tail lymphedema model. Embryonic stem cells (ESCs) from the reporter line were implanted in NOD-SCID mice to examine their ability to differentiate into lymphatic endothelium.
RESULTS: Strong reporter expression consistent with endogenous Prox1 expression enabled direct visualization of well-organized lymphatic vascular networks in the expected distribution of tissues, including skin, mesentery, and lymph nodes. This permitted rapid characterization of lymphangiogenesis in all models. Reporter line ESCs implanted into NOD-SCID mice differentiated into lymphatic endothelium and formed structurally normal lymphatic vessels.
CONCLUSIONS: The Prox1-tdTomato reporter line recapitulates endogenous lymphatic-specific gene expression patterns and enables the direct visualization of lymphangiogenesis in a variety of models. Reporter line ESCs may be useful for the real-time monitoring of lymphatic endothelial differentiation, elucidating an otherwise poorly understood process.